User Guide of PRO II 9.3

SimSci ®

PRO/II® 9.3 User Guide

May 2014

All rights reserved. No part of this documentation shall be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of Invensys Systems, Inc. No copyright or patent liability is assumed with respect to the use of the information contained herein. Although every precaution has been taken in the preparation of this documentation, the publisher and the author assume no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein. The information in this documentation is subject to change without notice and does not represent a commitment on the part of Invensys Systems, Inc. The software described in this documentation is furnished under a license or nondisclosure agreement. This software may be used or copied only in accordance with the terms of these agreements. © 2014 by Invensys Systems, Inc. All rights reserved. Invensys Systems, Inc. 26561 Rancho Parkway South Lake Forest, CA 92630 U.S.A. (949) 727-3200 http://www.simsci.com/ For comments or suggestions about the product documentation, send an e-mail message to [email protected]. All terms mentioned in this documentation that are known to be trademarks or service marks have been appropriately capitalized. Invensys Systems, Inc. cannot attest to the accuracy of this information. Use of a term in this documentation should not be regarded as affecting the validity of any trademark or service mark. Invensys, Invensys logo, PRO/II, and SimSci are trademarks of Invensys plc, its subsidiaries and affiliates.

Table of Contents Chapter 1 Using PRO/II ........................................................................................ 1 Before Starting PRO/II ..................................................................................... 1 Starting PRO/II.................................................................................................. 1 PRO/II Main Window Components ................................................................. 3 Using the Menus .............................................................................................. 6 Using the PFD Floating Palette ...................................................................... 9 Using the PFD Palette Button ....................................................................... 10 Using the Toolbars ........................................................................................ 10 Using the Customize Icon Pallette .............................................................. 11 Using the PRO/II Main Window..................................................................... 19 Chapter 2 Simulation Basics............................................................................ 21 General Approach .......................................................................................... 21 Run the Process Simulation ........................................................................ 22 Analyze the Simulation Results ................................................................... 23 Building the Flowsheet ................................................................................. 23 Unit Operations ............................................................................................ 23 Streams ....................................................................................................... 23 Required Data................................................................................................. 23 Components ................................................................................................ 23 Thermodynamic Methods ............................................................................ 24 Stream Information ...................................................................................... 24 Unit Operations ............................................................................................ 24 Optional Data.................................................................................................. 25 Miscellaneous Data ..................................................................................... 25 Miscellaneous Calculation Options ............................................................. 26 Default Data ................................................................................................. 28 Other Optional Data..................................................................................... 28 Chapter 3 Managing Simulation Files ............................................................. 29

Table of Contents - I

Opening a New Simulation ........................................................................... 29 Opening an Existing Simulation................................................................... 30 Saving the Current Simulation ..................................................................... 30 Closing a Simulation ..................................................................................... 32 Deleting a Simulation .................................................................................... 32 Copying a Simulation .................................................................................... 33 Importing a PRO/II Keyword Input File ........................................................ 35 Keyword Features without PRO/II GUI support .......................................... 36 Keyword Features Imported in “Run-Only” Mode ....................................... 36 Exporting Simulation Data to a File ............................................................. 38 Export Simulation Data to a Keyword File ................................................... 39 Exporting the Flowsheet Drawing to the Clipboard ..................................... 40 Exporting Stream or Unit Property Table Data ............................................ 40 Exporting Stream Property Table Data to Stream Report Writer ................ 41 Exporting the PFD to an AutoCAD .............................................................. 41 Exporting Tag Data to a File ........................................................................ 42 Exporting Data to Excel Using Spreadsheet Tools .................................... 42 Copying Property Table Data to the Clipboard ........................................... 42 Copying/Pasting Stream Data in an Excel Sheet........................................ 43 Chapter 4 Building a Flowsheet ...................................................................... 44 Setting Simulation Preferences.................................................................... 44 Setting Problem Description Global Defaults .............................................. 44 Overriding the Global Default Problem Description .................................... 45 Setting Units of Measure Global Defaults ................................................... 45 Changing Global Units of Measure for One Simulation .............................. 46 Units of Measure Library ............................................................................. 48 Setting Thermodynamic System Global Defaults ........................................ 52 Changing Delete Confirmation .................................................................... 53 Setting Global Flowsheet Tolerances.......................................................... 53 Placing a Unit on the Flowsheet................................................................... 54

Drawing Streams ........................................................................................... 57 Drawing a Connection ................................................................................. 59 Connecting Streams When One Unit is Not Visible .................................... 60 Labeling a Stream ....................................................................................... 60 Moving Streams........................................................................................... 61 Searching for a Unit or Stream .................................................................... 61 Drawing Freehand Objects ........................................................................... 62 Entering Text ............................................................................................... 62 Drawing Lines .............................................................................................. 63 Drawing Shapes .......................................................................................... 64 Drawing Pages ............................................................................................ 64 Chapter 5 Manipulating Objects ...................................................................... 67 Selecting Objects or Groups of Objects ..................................................... 67 Selecting Multiple Objects ........................................................................... 67 Selecting a Group of Objects ...................................................................... 68 Resizing Objects ............................................................................................ 69 Rearranging Objects or Groups of Objects ................................................ 70 Editing Text .................................................................................................... 72 Chapter 6 Viewing Flowsheet Contents .......................................................... 73 Scrolling the PFD ........................................................................................... 73 Zooming .......................................................................................................... 73 Opening Multiple Viewport Windows .......................................................... 75 Redrawing the Simulation ............................................................................. 75 Panning ........................................................................................................... 76 Moving the Bounding Box ............................................................................ 77 Chapter 7 Data Entry Windows ......................................................................... 79 Defining the Simulation ................................................................................. 79 Selecting Components .................................................................................. 80 Modifying Component Properties ................................................................ 81 Selecting Thermodynamic Methods ............................................................ 82

Table of Contents - III

Selecting Assay Data .................................................................................... 84 Specifying Reaction Data .............................................................................. 84 Specifying Reaction Procedure Data ........................................................... 86 Specifying Multiple Simulations for Case Study ........................................ 86 Setting the Problem Calculation Sequence ................................................ 87 Specifying Recycle Convergence ................................................................ 89 Data Entry Windows for Unit Operations .................................................... 90 Grids and the X-Y Grid ................................................................................ 91 Chapter 8 Specifying Component, Thermodynamic and Stream Data ........ 96 Component Data ............................................................................................ 96 Selecting Library Components .................................................................... 96 Entering User-defined Components ............................................................ 98 Modifying Component Properties .............................................................. 100 PRO/II and TDM Integration ...................................................................... 102 Assay Data.................................................................................................... 104 TBP Cut point Sets .................................................................................... 105 Assay Characterization Options ................................................................ 106 Thermodynamic Data .................................................................................. 107 Selecting Predefined Method Sets ............................................................ 108 User-added Thermodynamic Data ............................................................ 114 CAPE-OPEN Property Package................................................................ 114 Property Calculations .................................................................................. 114 Defining Transport Properties .................................................................... 115 Specifying Water Decant Options .............................................................. 116 Stream Data .................................................................................................. 120 Specifying Composition Defined Streams ................................................. 121 Specifying Stream Thermal Condition ....................................................... 122 Specifying Petroleum Assay Streams ....................................................... 122 Specifying Recycle Streams ....................................................................... 125 Scaling Product Streams ........................................................................... 127

Specifying Reference Streams .................................................................. 128 Copying Stream Data ................................................................................ 128 Refinery Inspection and User-defined Properties .................................... 132 Entering Refinery Inspection Properties .................................................... 133 User-defined Special Properties ................................................................ 134 Entering Assay Data for Stream Special Properties ................................. 134 Assay Data for Refinery Inspection Properties ......................................... 135 Assay Data for User-defined Special Properties ....................................... 135 BVLE (Validating Equilibrium Data) ........................................................... 140 Chapter 9 Unit Operations and Utility Modules ........................................... 142 Calculator ..................................................................................................... 143 General Information ................................................................................... 143 Sample Calculator Procedures .................................................................. 159 CAPE-OPEN.................................................................................................. 163 Column, Batch.............................................................................................. 167 Column, Distillation ..................................................................................... 168 Column Algorithm ...................................................................................... 169 Reactions ................................................................................................... 170 Pressure Profile ......................................................................................... 172 Condensers ............................................................................................... 173 Reboilers ................................................................................................... 174 Heaters and Coolers.................................................................................. 175 Flash Zones ............................................................................................... 175 Column Heat Leaks ................................................................................... 175 Pumparounds and Vapor Bypasses .......................................................... 176 Initial Estimates ......................................................................................... 176 Homotopy Options for Convergence on Specification .............................. 180 Tray Hydraulics.......................................................................................... 181 ®

Column RATEFRAC Tray Options .......................................................... 181 ®

Column RATEFRAC Packing Options ..................................................... 182

Table of Contents - V

®

RATEFRAC Transport Calculation Methods ........................................... 183 Tray Efficiencies ........................................................................................ 184 Side Columns ............................................................................................ 184 Print Options .............................................................................................. 185 Thermodynamic Systems .......................................................................... 185 Column, Liquid–Liquid Extraction ............................................................. 185 Column Algorithm ...................................................................................... 187 Pressure Profile ......................................................................................... 187 Heaters and Coolers.................................................................................. 188 Initial Estimates ......................................................................................... 188 Performance Specifications ....................................................................... 189 Print Options .............................................................................................. 190 Thermodynamic Options ........................................................................... 190 Column, Side ................................................................................................ 190 Solution Methods ....................................................................................... 191 Compressor .................................................................................................. 192 Pressure, Work, or Head Specification ..................................................... 193 Controller ...................................................................................................... 196 Counter Current Decanter ........................................................................... 198 Crystallizer.................................................................................................... 199 Cyclone ......................................................................................................... 202 Rotary Drum Filter ....................................................................................... 208 Solids Dryer .................................................................................................. 210 Melter/Freezer............................................................................................... 212 Depressuring Unit ........................................................................................ 213 Dissolver ....................................................................................................... 219 Filtering Centrifuge ...................................................................................... 220 Excel Unit...................................................................................................... 227 Data Transfer Sheet .................................................................................. 230 Expander....................................................................................................... 233 Flash .............................................................................................................. 235

Flash With Solids ......................................................................................... 238 Flowsheet Optimizer .................................................................................... 239 Heat Exchanger, LNG .................................................................................. 244 Heat Exchanger, Air Cooled ....................................................................... 246 Heat Exchanger, Rigorous .......................................................................... 247 Heat Exchanger, Simple .............................................................................. 256 Heating/Cooling Curves .............................................................................. 260 Mixer.............................................................................................................. 269 Multivariable Controller ............................................................................... 270 Phase Envelope ........................................................................................... 272 PIPEPHASE Unit Operation ........................................................................ 273 Pipe ............................................................................................................... 276 Line/Fitting Data ........................................................................................ 278 Line Sizing Data ........................................................................................ 279 Polymer Reactor .......................................................................................... 281 Procedure Data ............................................................................................ 282 Procedure Code ........................................................................................ 283 Pump ............................................................................................................. 290 Reaction Data ............................................................................................... 291 Reactor .......................................................................................................... 294 Conversion and Equilibrium Reactors ...................................................... 296 Continuous Stirred Tank Reactor .............................................................. 296 Plug Flow Reactor ....................................................................................... 297 Boiling Pot Reactor ..................................................................................... 300 Gibbs Reactor .............................................................................................. 301 Unit Reaction Definitions ............................................................................ 302 Reactor, Batch.............................................................................................. 307 Solid Separator ............................................................................................ 308 Splitter ........................................................................................................... 309 Stream Calculator ........................................................................................ 310 Specifications............................................................................................... 313

Table of Contents - VII

VARY ............................................................................................................. 315 DEFINE .......................................................................................................... 317 User-added Unit Operations ....................................................................... 329 Customized UAS Data Entry Window ....................................................... 332 Modular User-Added Unit Operations ....................................................... 333 Modular User-Added Utilities ..................................................................... 334 Detailed Information .................................................................................. 334 Electrolytic Column Algorithm (ELDIST) ................................................... 337 Simsci Add-on Modules .............................................................................. 337 SIMSCI POLYMER CSTR Unit Operation ................................................ 337 SIMSCI COMPONENT PROPERTY REPORTER Unit Operation ........... 338 SIMSCI BLEND Unit Operation ................................................................. 339 SIMSCI RESET Unit Operation ................................................................. 339 SIMSCI Profimatics Reactor Unit Operations ........................................... 340 Valve .............................................................................................................. 340 Wiped Film Evaporator ................................................................................ 341 Chapter 10 Running and Viewing a Flowsheet ............................................ 343 Using the Run Toolbar ................................................................................ 343 Checking the Simulation Status ................................................................. 344 Understanding the Unit Color Coding Cues .............................................. 345 Running the Simulation .............................................................................. 346 Stepping Through Simulation Execution ................................................... 347 Stopping Simulation Execution .................................................................. 347 Using Breakpoints ..................................................................................... 348 Viewing Results ......................................................................................... 349 Selecting Streams for Property Tables...................................................... 351 Customizing the Stream Property Tables ................................................. 351 Defining Stream Property Lists (Formats) ................................................. 352 How Stream Property Tables Persists on File Save and File Open ......... 354 Mapping the Stream Property Table to the Stream Report Writer ............ 354

Running a Case Study ................................................................................. 356 Viewing Case Study Results ..................................................................... 358 Running Files in Batch Mode ..................................................................... 358 Revising the File Execution Sequence Order ........................................... 362 Creating an Execution File List.................................................................. 362 Executing the Batch List ............................................................................ 363 Viewing Output Results ............................................................................. 363 Chapter 11 Printing and Plotting .................................................................... 364 Defining Output Reports ............................................................................. 364 Generating a Report .................................................................................... 372 Plotting.......................................................................................................... 373 Chapter 12 Customizing the PFD Workplace ................................................ 379 Changing Unit Operation Styles................................................................. 379 Changing the Unit Icon Globally ................................................................ 380 Changing the Unit Icon for a Single Unit ................................................... 381 Changing the Label Displayed for a Specific Unit ..................................... 382 Changing Stream Styles ............................................................................. 383 Changing the Global Stream Style ............................................................ 383 Display Stream Property Lists As Stream Labels ..................................... 386 Create Custom Stream Property Lists ....................................................... 387 Changing the Style of an Individual Stream ............................................. 389 Changing the ID Name of an Individual Stream ........................................ 390 Toggle Stream Property List Button .......................................................... 392 Adding the Toggle Stream Button to the Tool Bar .................................... 393 Customizing Stream ToolTips .................................................................... 395 Modifying Drawing Preferences ................................................................. 397 Specifying a Default Editor ......................................................................... 397 Changing the Default Font .......................................................................... 397 Index ....................................................................................................................... i

Table of Contents - IX

Chapter 1 Using PRO/II This chapter describes how to start and exit PRO/II. In addition, it reviews some basic Windows features as they appear in PRO/II and briefly describes how to use them.

Before Starting PRO/II If you have not yet installed PRO/II on your system, see the PRO/II PC/LAN Installation Guide. If you do not see a PRO/II icon in a SIMSCI group window or in your Program/SIMSCI Start menu, see the troubleshooting section in the PRO/II PC/LAN Installation Guide.

Compatibility with Previous Versions This release of PRO/II can read simulation files created by previous versions of PRO/II. When you open a simulation file created by a previous version, the file is automatically converted to the current version, and a copy of the original file is saved under a different name. For example, if you open G3.prz that was created by PRO/II version 6, the converted file will be saved as “G3.prz” and a copy of the original file will be saved as “G3_v60.prz”. Note: Some keyword input files created manually may include features that are not supported by the PRO/II graphical user interface. PRO/II issues a warning when this occurs. For flowsheet execution, all features will be preserved if you choose either the Read Only or Run Batch mode. In all cases, if you subsequently export the problem, all unsupported features will be lost. The exported file will not include any of the unsupported features. Later import of an exported file will reveal that the unsupported features are missing. It is always prudent to make copies of your original files and to work only on the copies of the original files.

Starting PRO/II To start PRO/II: 

Double-click the PRO/II icon, or launch from the Start menu.

The PRO/II welcome window appears. This window contains information on opening files and on the color codes used in the program.

Chapter 1

Using PRO/II 1

Figure 1-1 PRO/II Welcome Window

2 PRO/II User Guide

April 2014



Click OK to close this window and open the PRO/II main window.

Figure 1-2: The PRO/II Main Window You can now open a new simulation file (select File/New), open an existing file (select File/Open), or import a keyword file (select File/Import). See Chapter 3, Managing PFD Files, for additional details.

PRO/II Main Window Components Component

Description

Control Menu Box

Displays a menu with commands for sizing, moving and closing the active window.

Title Bar

Identifies the application and the name of the open file; can be used to move the entire window.

Minimize Button

Reduces the application window to an icon.

Maximize/Restore Button

Enlarges a window to full screen or restores it to its default size

Menu Bar

Identifies the menus available in PRO/II: File, Edit, Input, Output, Tools, Draw, View, Options, Window and Help.

Chapter 1

Using PRO/II 3

Component

Description

Toolbar

Provides push button access to various Edit, Input, Tools, View, Window, and Help options

PFD Main Window

Provides a workspace for placing units, making stream connections, drawing objects, and adding text.

Horizontal Scroll Bar

Functions as a sliding scale for moving the flowsheet to the right or left in the PRO/II main window.

Vertical Scroll Bar

Functions as a sliding scale for moving the flowsheet up or down in the PRO/II main window.

Status Bar

Displays help, information and error messages for the active feature or object.

Border Handles

Changes window height, width, or size when the corresponding border handle is dragged to a new position.

Manipulating the PRO/II Window The PRO/II window offers many features that enable you to customize its appearance, relative to the full screen and other applications. Detailed instructions on use of the Windows’ graphical user interface may be found in numerous reference manuals available at any large bookstore.

Changing Window Size The Windows interface provides tools for resizing each window. Some tools automatically change a window to a particular size and orientation; others enable you to control the magnification.

Using Minimize/Maximize Buttons The minimize and maximize buttons automatically adjust the size of a window.

Using Border Handles You can use the window border to change the size of the main window. The border works like a handle that you can grab with the cursor and drag to a new position.

4 PRO/II User Guide

April 2014

Using the Control Menu In addition to the border handles, you can also use the Control menu to Restore, Move, Size, Minimize, or Maximize a window. Open the Control menu by clicking the PRO/II icon at the far left of the title bar or by pressing .

Changing Window Position You can change the position of the main window (or any pop-up window) by dragging the title bar.

Working with On-screen Color Coding Cues PRO/II provides the standard visual cue (grayed out text and icons) for menu items and toolbar buttons that are currently unavailable. In addition, PRO/II uses colored borders liberally to indicate the current status of the simulation. You may customize the color coding by accessing the Set Colors window by selecting Options/Colors… from the menu bar.

PRO/II On-Screen Color Codes Color

Significance

Red Required data

Actions or data required of the user

Green

Optional or default data

Blue

Data supplied by user

Yellow

Questionable data. A warning that the value supplied by user is outside the normal range.

Gray

Data field not available to user

Black

Data entry not required

Chapter 1

Using PRO/II 5

Using the Menus The names of the PRO/II main menus appear on the menu bar. Use these menus to access most PRO/II operations.

Figure 1-3: File Menu Figure 1-4: Edit Menu

6 PRO/II User Guide

April 2014

Figure 1-6: Run Menu

Figure 1-5: Input Menu

Figure 1-6: Output Menu

Chapter 1

Using PRO/II 7

Figure 1-9: Draw Menu

Figure 1-8: Tools Menu

Figure 1-10: View Menu

Figure 1-11: Options Menu

8 PRO/II User Guide

April 2014

Figure 1-13: Help Menu

Figure 1-12: Window Menu

Using the PFD Floating Palette The PFD Floating Palette contains the unit operations and streams needed to construct a flowsheet. This palette may be displayed or hidden by selecting View/PFD Palette from the menu bar. Menu Item

Description

View/Palettes/PFD

Checking this option displays the PFD palette containing unit operations and streams (also known as the Streams/Unit palette).

Chapter 1

Using PRO/II 9

Using the PFD Palette Button This button is a toggle that hides or displays the floating PFD palette. Menu Item View/PFD Palettes

Description Displays the PFD palette containing unit operations and streams (also known as the Streams/Unit palette).

Using the Toolbars PROII Toolbars are grouped into 5 categories: Standard, Input, Run, Flowsheet, Output and PFD. These toolbars show only the buttons that you have used most recently. Toolbar buttons duplicate options available from the menus on the menu bar. Simply click a button to perform its function. Hovering the mouse cursor over a button without clicking displays a tool tip that identifies the button. When PRO/II is first installed, several groups of buttons are visible. Many others are available. •

New, Open, Save, and Print

•

Show or Hide PDF Palette

•

Data Entry Window buttons (Input, Component Selection, etc.)

•

Navigation Aids (Pan, Find and Rename Units, Find and Rename Streams)

•

VLE Tool buttons

•

Run/Results buttons

•

Delete and View buttons

•

Help button

10 PRO/II User Guide

April 2014

Using the Customize Icon Pallette The Customize Icon Palette option can be used to customize the icons present on the icon palette. This option enables the user to create a new tab, reorder the existing tabs, delete an existing tab or edit the unit operations present in a tab. The Icon Palette Tab Manager window can be accessed by clicking Customize Icon Palette from Options menu.

Figure 1-7: Icon Palette Tab Manager

Chapter 1

Using PRO/II 11

A summary of the buttons available on the Icon Palette window is provided below: Button

Description Move the selected tab upward one position. Move the selected tab downward one position Create a new tab on the Icon Palette. Rename the selected tab on the Icon Palette. Delete the selected tab from the Icon Palette. Edit the unit operations present in the tab. Restore the icon palette supplied by install.

To add a new tab: 

Highlight a tab.



Click New, to open the New Tab window.

Figure 1-8: New Tab Window 

Enter the new name in the Tab Name field.



Click OK. By default “Custom” is the tab name that appears on the New Tab dialog box. Note: The tab name must be unique.


April 2014

To rename a tab: 

Highlight a tab.



Click Rename, to open the Rename Tab window. By default the selected tab name appears in the edit field of the Rename Tab window.

Figure 1-9: Rename Tab Window 

Enter the name to be replaced in the Tab Name field.



Click OK.

To delete a tab: 

Highlight a tab.



Click Delete. A message appears on the screen to confirm the actions for deleting.

Figure 1-10: Delete Tab Window 

Click Yes to continue.



Click NO to cancel.

To edit the unit operations in the tab: 

Highlight a tab.



Click Edit, an Edit Tab window appears as shown in Figure 1-11.

Chapter 1

Using PRO/II 13

This window contains Up, Down, Top, Bottom, Insert and Delete buttons to reorder, to insert an available unit operation and to delete an existing unit operation from the selected tab. Same unit operation can be added to more than one tab.

Figure 1-11: Edit Tab Window


April 2014

A summary of the buttons available on the Edit Tab window is provided below: Button

Description

Move the selected unit operation upward one position.

Move the selected unit operation downward one position.

Move the selected unit operation to the top of the list.

Move the selected unit operation to the bottom of the list. Insert the selected available unit operations just before the highlighted unit operation in the unit operation list box. Delete the selected unit operation from the Unit Operations List box. A message appears on the screen to confirm the actions for deleting.

Using the Data Entry Window Buttons Each Data Entry Window button provides quick access to the main data entry window for the selected section of input. Button

Menu Item

Description

Input/Problem Description

Describes the current simulation and relates it to a specific project.

Input/Units of Measure

Sets units of measure specific to this simulation. Each new simulation extracts defaults from the default Unit of Measure Set.

Input/Component Selection

Specifies the components and pseudo components for the current simulation.

Input/Component Properties

Supplies component properties.

Chapter 1

Using PRO/II 15

Input/Thermodynamic Data

Selects thermodynamic methods for the current simulation.

Input/Launch TDM

Launch Thermo Data Manager

Input/Assay Characterization

Modifies TBP cut points and characterization options for generating pseudo components from Assay streams.

Input/Reaction Data

Defines reactions and provides heat of reaction, equilibrium, or kinetic data for reaction sets.

Input/Reaction Procedure

Use this window to create or delete Procedure blocks in order to calculate kinetic reaction rates.

Input/Casestudy Data

Allows users to perform studies on a base case solution by altering parameters and rerunning.

Input/Calculation Sequence

Specifies a user-defined calculation sequence.

Input/Recycle Data

Specifies user-defined recycle convergence and acceleration options.

Using Navigation Aid Buttons The Go To buttons enable you to jump to a selected unit or stream. PRO/II repositions the flowsheet to place the selected unit or stream at the center of the main window. The Find and Rename Streams and Find and Units buttons open windows that allow direct data entry and review of output results for the selected stream or unit, and bulk rename of the units or streams available in the flowsheet.

Button

Menu Item

Description

View/Pan View

Allows quick panning through the entire flowsheet.

Find and Rename Units

Displays a list of units in the current flowsheet. By selecting a name, you can jump directly to that unit. Also, you can rename the required units available in the flowsheet at one go.


April 2014

Find and Rename Streams

Displays a list of streams in the current flowsheet. By selecting a name, you can jump directly to that stream. Also, you can rename the required streams available in the flowsheet at one go.

Using VLE Tools Buttons The VLE Tools buttons enable you to perform simulation functions, e.g., flash, a stream highlighted on the PFD using the Flash Hot-key. Button

Menu Item

Description

Tools/Flash Stream

Flashes the stream highlighted on the PFD. (Also called the Flash Hot-key)

Tools/Binary VLE

Generates plots and tables of K-values and fugacity coefficients for binary pairs of components.

Using Run/Results Buttons The Run/Results buttons duplicate functions on the Run Simulation floating palette. They allow you to run, stop a simulation or permit viewing results and generate output reports. The Generate Output button duplicates an Output menu item. Button

Chapter 1

Menu Item

Description

Run/Run Simulation

Runs the simulation

Run/Stop

Stops the simulation

Output/Data Review Window

First, select any stream or unit on the PFD. Pressing this button displays the results of the selected PFD item.

Run/View Results

View Text Results Window. First, solve a simulation; then select any stream or unit on the PFD. Pressing this button displays results for the selected item similar to how they would appear in the complete output text report.

Output/Generate Text Report

Generates an output report for the simulation problem.

--------

Select Active report allows choosing which pre-defined report is currently

Using PRO/II 17

active. Output/Generate Excel Output

Generates an output report suitable for viewing by using Microsoft Excel

Using Delete and View Buttons PRO/II provides a Delete button and a set of View buttons on the toolbar that facilitate editing and viewing of the flowsheet. These buttons duplicate items available on the Edit and View menus. Button

Menu Item

Description

Edit/Delete or

Deletes the currently selected object(s) from the flowsheet.

Input/Toggle Stream Property List

User can select a particular stream property table as the toggle stream property list.

View/Zoom/Zoom Full or

Displays the entire flowsheet in the PFD window.

View/Zoom/Zoom In, Zoom Out

Zooms in or out of the flowsheet.

View/ Zoom/Zoom Area

Displays the selection rectangle used to select a set of units, streams or objects on the flowsheet. The selected area fills the PFD.

View/Zoom/Redraw or

Clears the PFD of any extraneous object by redrawing the flowsheet.

Using the Help Button The What Is? Help button displays context-sensitive help. Button

Menu Item What Is?

Description Displays help for the object you point to.

Customizing the Toolbar Buttons on the toolbar may be added, removed or rearranged by using the Toolbar… item on the View menu. Over 50 buttons are available.


April 2014

Figure 1-12: Toolbar Customization from View menu All items in the “Selected Items” list box from top to bottom appear in order left to right on the tool bar. Items in the “Available Items” list box do not appear on the tool bar. Use the Add, Add ALL, Delete, and Delete ALL buttons to move items between the two list boxes as desired. To add an item to the tool bar, 

Highlight an item in the “Available Items” list box.



Use the Add button to move it to the “Selected Items” list box.

To remove an item from the tool bar, 

Highlight an item in the “Selected Items” list box.



Use the Delete button to move it to the “Available Items” list box.

To change the order of items on the tool bar, 

Highlight an item in the “Selected Items” list box.



Use the Up, Down, Top, and Bottom buttons to change the position of the item in the list.

All changes take effect immediately after pressing OK.

Using the PRO/II Main Window The PRO/II main window (PFD) is the main drawing board. You may place the following objects on the PFD: 

Unit operations from the PFD palette



Stream connections

Chapter 1

Using PRO/II 19



Text



Drawings



Stream property tables

Use the PRO/II main window to see the contents of your simulation. You can choose to view the entire flowsheet or only a portion of it. You control the view using scroll bars, pan options, the zoom bar, or arrow keys. Note: See Chapter 5, Manipulating Objects, for information about placing, selecting and changing the size of objects in the PFD.


April 2014

Chapter 2 Simulation Basics In the previous chapter, you learned some of the basic window features of PRO/II. In this chapter, you will learn simulation basics; that is, how to set up simulation problems, solve them, and analyze the results.

General Approach This chapter provides a quick overview of the use of PRO/II for solving engineering problems. A suggested basic approach is given as well as helpful explanations of the information flow in PRO/II. Sample data entry windows are given to illustrate data entry for PRO/II. Step-by-step examples are available in the PRO/II Tutorial Guide. Online help is also available. You have already learned that PRO/II gives you great flexibility and numerous options when supplying simulation data. For many items of data, default values are supplied. A color code informs you when data are required, supplied by default, out of normal ranges, or missing. Note: You must supply data for all red-bordered fields or red-linked text (including data required) before running your simulation. Problem data may be supplied in almost any order: PRO/II warns you when required data are missing. However, it is still best to follow a logical path when supplying simulation data. For example, some options such as stream compositions are dependent upon the components selected. Some unit operations, such as the flash drum, have features that are dependent on the thermodynamic data. For some other unit operations, performance specifications based on the components in the system are the preferred way to define the operation. For these reasons, the following approach is recommended when building a simulation flowsheet.

Draw the Flowsheet Select the unit operations needed for the flowsheet calculations and position them on the PRO/II PFD main window.

Connect the Unit Operations with Streams The streams are the connectors for the process calculations, with information passed from one unit operation to another via the process streams.

Chapter 2

Simulation Basics 21

Define the Components in Your System It is best to order the components in volatility order, starting with the lightest component. This makes it easy to analyze the separations which occur in unit operations such as distillation. While not a necessity, for hydrocarbon/water systems, defining water as the first component is also a good idea. This makes it easy to see the break between the aqueous and non-aqueous phases. Userdefined petroleum pseudo components and/or polymer components for which you supply data should be entered next. Petroleum pseudo-components generated by PRO/II from petroleum stream assay data will appear last in the component lists of the output reports.

Select the Thermodynamic and Transport Property Methods For many problems, a system may be selected from the Most Commonly Used thermodynamic methods. Guidelines for thermodynamic methods are provided in the PRO/II online help, and in the PRO/II Reference Manual (both in online help and in hardcopy forms). Further assistance is available through SIMSCI Technical Support. Selecting a proper thermodynamic method is a critically important step in the solution of a simulation problem.

Supply Data for the Feed Streams and Recycle Streams You must supply thermal conditions, flow rates, and compositions for all external feed streams to the flowsheet. It is usually desirable, although not necessary, to provide estimated data for recycle streams to speed convergence of recycle calculations.

Supply Operating Conditions for the Unit Operations Double-click the icon for each unit operation to access the data entry windows. The color codes tell you what data you must supply and what data have default values. You may also use the online help to learn more about the calculation options, data entry items, etc., for each unit operation. A quick review is also a good idea at this point. Do the thermodynamic methods support the unit operation calculations? Are transport properties required for any of the unit operations?

Run the Process Simulation PRO/II lets you know, by color code, when sufficient information has been supplied to perform the calculations. When all of the borders on the toolbar icons have changed from red (indicating missing data) to green or blue, you are ready to run your simulation. At this point, you may click the Run (right arrow) icon on the Run toolbar or the Run button on the Run menu to begin the flowsheet calculations.


April 2014

Analyze the Simulation Results Use the many convenient report and plotting features of PRO/II to analyze the simulation results. At this point, your training as an engineer should take charge. Are the results reasonable? How do the results compare with the plant data? Can differences be reconciled? Are better data for the feed stocks needed? Are the models adequate for the intended purposes? Now that we have presented an overall plan for simulating a flowsheet, let’s look at some of the individual steps in more detail.

Building the Flowsheet Unit Operations Use the floating PFD palette to begin building the flowsheet. The icons and names for the unit operations appear as buttons on the PFD palette. To add a unit operation to the flowsheet, click the unit icon on the PFD palette and clickdrop it at the desired location on the flowsheet.

Streams Click the Streams button on the top of the floating PFD palette. The PFD is now in stream mode and a small “S” is attached to the cursor. You will notice that all possible exit ports for each unit operation are now marked. Required outlet ports are colored in red; green is used to mark optional ports. PRO/II adds each stream to the flowsheet in an orthogonal manner, following a rectangular grid pattern. As soon as a valid flowsheet has been built, i.e., all required inlet, outlet, and connector streams have been added for all the process units, the red border around the Streams button on the PFD palette changes to blue.

Required Data Now that the flowsheet has been built, it’s time to supply the required data for the calculations: the components and thermodynamic methods must be defined, inlet feed streams and, optionally, recycle streams must be supplied, and the operating conditions for the unit operations must be specified.

Components To define the components, select Input/Component Selection from the menu bar or click on the benzene ring toolbar icon to open the Component Selection main window. Note that this icon has a red border, indicating that components have not yet been defined.

Chapter 2


Library components for which the library access names are known may be directly typed into this window, where they are transferred to the List of Selected Components for the problem. A convenient search procedure is also provided which may be used by clicking Select From Lists… Petroleum (PETRO) components are defined in the Petroleum Components window, which is reached by clicking Petroleum…. Non-library components can be defined in the Userdefined window which is reached by clicking User-defined…. Note that petroleum pseudo-components defined by PRO/II from petroleum stream assay data do not appear in the Component Selection main window.

Thermodynamic Methods Thermodynamic methods are defined in the Thermodynamic Data main window which is reached by selecting Input/Thermodynamic Data from the menu bar or by clicking on the phase diagram icon. Note that this icon is initially outlined in red, indicating that thermodynamic methods must be defined for the problem. For most problems, a predefined set of thermodynamic methods for calculating K-values, enthalpies, entropies, and densities may be used. PRO/II offers numerous Categories of method sets. After a category has been selected, you may select a method set within that category as a Defined System for the problem and modify it by clicking Modify… to access the Thermodynamic System-Modification window. Note that transport property calculations are not included in the predefined method sets. If they are required for the problem, you must add them to the predefined thermodynamic method set in this window.

Stream Information The identifiers for feed streams requiring input data are marked with red borders indicating that information is missing. Stream information is supplied in the Stream Data main data entry window which is reached by double-clicking a stream identifier. The predefined stream identifier may also be changed in this window. Three types of information must be supplied in this window: the thermal condition of the stream, the flow rate for the stream, and the composition of the stream. For petroleum assay streams, the assay data are provided instead of the composition data, and PRO/II defines the stream composition for you in terms of petroleum pseudo-components. Although optional, it is good practice to provide reasonable estimates for recycle tear streams in order to accelerate convergence of problem recycle calculations.

Unit Operations Unit operation identifiers for which data entries are needed are marked with red borders. To enter information for a unit operation, double-click its icon to retrieve


April 2014

the Unit data entry window. Various input options and numeric values are supplied via this parent window and its child windows. Required information is always bordered in red; data entry fields for items with supplied defaults are always bordered in green. After supplying information in a data entry field, the border color changes to blue. Information you have supplied which lies outside the normal range for the field is marked with a yellow border. You may also change the default unit identifier in this window and furnish a longer, more descriptive name for the unit operation. Notice that when you return to the flowsheet, the unit identifier on the PFD has a black instead of red border, signifying that all data entry requirements are satisfied. If the border is still red, you must return to the data entry window for that unit operation and supply the missing data.

Optional Data Miscellaneous Data All data entries in these categories are optional because PRO/II provides default values for all the options. In some cases, global values may be used to supply the defaults, as explained in Chapter 4, Building a Flowsheet. Miscellaneous data categories include problem descriptive information, the calculation sequence, recycle convergence options, flowsheet tolerances, and the scaling of product streams. Problem descriptive information is optional; however, it can be beneficial to document a simulation model for future users. This information includes a project name, problem name, user name, date, site, and problem description. This information is supplied in the Problem Descriptive Information window, which is with the printed page icon or by accessed by clicking the toolbar icon selecting Input/Problem Description from the menu bar. For most problems, the calculation order determined by PRO/II is satisfactory. To with the two connected supply your own sequence, click the toolbar icon flowsheet blocks or select the Input/Calculation Sequence from the menu bar. Definitions of recycle loops are automatic. To define your own loops, or to use with the flowsheet loop icon to acceleration techniques, click the toolbar icon enter the Problem Recycle Convergence and Acceleration Options window or select the Input/Recycle Convergence from the menu bar. Flowsheet tolerances are used for convergence of unit operation specifications and may be changed in the Default Unit Specification Tolerances window, which is reached by choosing Input/Flowsheet Tolerances from the menu bar. All flowsheet results may be scaled so that a desired flow is obtained for a product stream. To use the scaling feature, select the Output/Report

Chapter 2


Format/Miscellaneous Data. Click Product Stream Scaling… on the Miscellaneous Report Options window to access the Scale Stream Flow rate window.

Miscellaneous Calculation Options PRO/II has default settings for many global calculation settings, but in some simulations it may be desirable to employ alternative settings. The options described here correspond to entries in the General Data category of keyword input. They are more fully described in Chapter 5 of the PRO/II Keyword Input Manual. Note: Chapter 4 of this Guide describes additional settings available through the Options menu. To access these calculation settings in ProVision, navigate to Input/ Miscellaneous Data from the menu bar. This displays the Input Miscellaneous Data dialogue:

Figure 2-1: Miscellaneous Calculations Options Include Exergy Analysis: Placing a check mark in this checkbox requests exergy calculations after the flowsheet has solved. These calculations do not affect flowsheet convergence. This corresponds to the EXERGY statement of General Data keyword input.


April 2014

Component Data: Controls the component slates used in each thermodynamic METHOD set. The default Fixed option forces all thermodynamic sets to use the same component properties uniformly. The Variable option allows each METHOD set to use different properties for the components. This is equivalent to the CDATA option on the CALCULATION statement of General Data keyword input. Polymer Mode Consistency Check: Set Yes by default, this generates a report of how the phases available for polymer components agree with the phases available in the thermodynamic methods. This option takes very little time, and there is no substantial advantage for using the No option. This is equivalent to the PCONVERSION option on the PRINT statement of General Data keyword input. (It is used so rarely it no longer is documented in the Keyword Manual.) Thermo/Phase Designation Consistency Check: This checks that the phases declared in the thermodynamic METHOD sets are compatible with the phase designations of non-polymer components. The default Calculation Time setting performs the checks each time thermodynamic calculations are initiated. The Input Time option performs the checks only once, before flowsheet calculations begin. Performing the checks during calculations has very little impact on the elapsed solution time. This is the same as the COMPCHECK option on the CALCULATION statement of General Data keyword input. Independent Variable Check: In equilibrium calculations where the dependent variable (y) is relatively insensitive to the independent variable (X), the default ON setting forces relatively large changes in the independent variable. This helps ensure the solution is near the local optimum. The OFF option accepts any valid solution that is merely “within tolerance”, but may be desirable in rare situations. This is equivalent to the DVARIABLE option on the CALCULATION statement of General Data keyword input. Flash Algorithm: PRO/II incorporates several strategies for solving flash calculations. Each strategy has unique strengths and weaknesses. The Default setting is robust, and is appropriate for most simulations. The before Version 5.5 setting closely replicates the flash results obtained in older versions of PRO/II. The Alternate setting is recommended when the Default method fails, especially when two liquid phases are expected. For more description, refer to the FLASH option on the CALCULATION statement of General Data keyword input. Maximum Node Calculations: This entry sets the maximum number of unit operations and branching decisions allowed during flowsheet solution. The default number is adequate for virtually all simulations. See the MAXOPS entry on the CALCULATION statement of General Data keyword input.

Chapter 2


Default Data To simplify data input, PRO/II supplies default options and values wherever practical. Default values supplied by PRO/II are printed in black in a data entry field with a green border, or in the case of linked text, in green. For example, the default number of iterations for a column unit operation using the IO method is supplied as 15. Entries which you must always supply are indicated with a color red because they have no default values. While it is not necessary to replace a default entry to satisfy PRO/II input requirements, default data should be inspected carefully to ascertain that they meet your requirements. After replacing a default value, the border color for the data entry field changes to blue, indicating that you have supplied this value. For linked-text strings, the color of the linked text is also changed to blue, indicating that you have replaced the default value.

Other Optional Data Optional data, which are displayed in black, are data or options not specifically necessary for the unit operations to proceed. For example, the Description entry is optional for all unit operations. A reboiler is optional for the Column unit operation, since the calculation requirements may also be satisfied by a vapor feed to the bottom tray of the column. Data options which do not apply to a particular combination of input data appear in the color gray, and are not available for data entry. For example, when the kettle reboiler option is selected for a column reboiler, the data entry fields for a thermosiphon reboiler are colored gray.


April 2014

Chapter 3 Managing Simulation Files This chapter describes how to open, save, close, delete and copy simulation files. In addition, this chapter outlines how to import a PRO/II keyword input file or export a flowsheet.

Opening a New Simulation When you start PRO/II, the program does not automatically bring up a new, untitled simulation. Note: If you want PRO/II always to open with a new simulation, select Options/New File on Startup from the menu bar.

To open a new simulation: 

Choose File/New... from the menu bar. PRO/II clears the main window for a new simulation and opens the initial viewport window, View 1.

Figure 3-1: PRO/II Main Window

Chapter 3

Managing PFD Files 29

Opening an Existing Simulation You can open any previously saved simulation for modification, viewing or printing. PRO/II opens the flowsheet file and its supporting PRO/II database files.

To open an existing simulation: 

Choose File/Open... from the menu bar. PRO/II displays the Open Simulation window.

Figure 3-2: Open Simulation Window 

Type or select the name of the simulation file.



Click Open or press . PRO/II displays the simulation in the PFD main window.

Note: PRO/II 7.x provides a file converter for import of PRO/II 4.x files with the exception of Add-On Module files.

Saving the Current Simulation Before you close a simulation, you should save it. You may also want to save the simulation periodically while creating it.

To save the current simulation: 

Choose File/Save from the menu bar. If you have not previously saved this simulation, PRO/II displays the Save As window.

Note: PRO/II 5.x automatically compresses the three PRO/II database files (*.pr1, *.pr2, *.pr3) and the simulation flow diagram file (*.sfd) into a single


April 2014

*.prz file. Besides reducing the size of stored files, PRO/II file compression assures that a complete set of files for each simulation has been saved.

Figure 3-3: Save As Dialog 

Type a name for this simulation.



Click Save or press .

Note: The PRO/II Autosave functionality automatically creates a backup file at user-specified intervals from which recovery can be made. If you close or exit the simulation without saving, this backup file is deleted. Select Options/Simulation Defaults/Autosave… from the menu bar to access the Autosave Options window.

Saving a Simulation to Another Name You can save a simulation to another name. Changes you made to the simulation since the last save are saved as part of the simulation, under its new name. Note: If you’ve made changes to a simulation and don’t want to alter the original simulation, but do want to keep the changes, use Save As.

To save the current simulation to another file name: 

Choose File/Save As... from the menu bar.

PRO/II prompts you for a new file name. 

Type a name for the simulation.

Chapter 3




Click Save or press .

PRO/II appends a .PRZ extension to the filename.

Closing a Simulation You should save a simulation before closing it, although PRO/II will prompt you to save changes for an existing simulation.

To close a simulation: 

Choose File/Close from the menu bar.

If you close a simulation without first saving the simulation files, you lose any changes you made to the simulation since the last save.

Deleting a Simulation You can delete any simulation except the current (active) simulation at any time.

To delete a simulation file: 

Choose File/Delete... from the menu bar. PRO/II displays a list of existing PRO/II simulation files.

Figure 3-4: List of Files 

Type or select the name of the file you want to delete. (You may not delete the current simulation.)



Click Open or press . PRO/II deletes all files associated with this simulation.


April 2014

Copying a Simulation You can copy all files associated with a simulation (one flowsheet and three database files) to a target simulation you name. You can copy to new or existing file. If you copy to an existing file, PRO/II verifies if you want to overwrite the existing file.

To copy a simulation file: 

Choose File/Copy... from the menu bar. This opens the dialog illustrated in Figure 3-5.

Figure 3-5: Copying Files 

Select the name of the file you want to copy from the file selector. (You may not copy the current simulation.)



Enter a name for the copy (target).

 Click Open or press . PRO/II copies all files associated with the simulation. Note: There may be as many as 17 separate files associated with a single simulation problem. These are described in Table 3-1.

Chapter 3


Table 3-1: PRO/II Simulation Files File Extension

Description

*.pr1, *.pr2, *.pr3

PRO/II database files

*.sfd

Graphics file

*.prz

Compressed files containing *.pr1, *.pr2, *.pr3 and *.sfd files

*.out

Main output file

*.ot1

Component, calculation sequence, recycle loops/streams output data

*.ot3

Equipment/streams output data

*.sr1

Input source listing

*.ix3

Output index

*.hs2

Calculation history

*.inp

Keyword input file

*.plt

Plots saved in the plot display window

*.txt

Stream property table or plot (saved in ASCII format)

*.csv

Stream property table or plot (saved in tabular format)

*.clp

Graphics saved in Clipboard format


April 2014

*.prc

Temporary procedure file created and removed by PRO/II. Only remains if there is an abnormal termination.

Importing a PRO/II Keyword Input File You can import an existing PRO/II keyword input file into the PRO/II graphical user interface and then execute the simulation problem just as if you had entered the problem using the PFD graphical main window. PRO/II automatically converts the specified keyword input file into a flowsheet and displays it in the PFD window. Note: In the previous versions, PFD layout was retained within the *.prz file. In the current version, *.sfd file will be generated, when a simulation (PFD) is saved and exported. After the generation of *.sfd file, users can restore the PFD layout using *.inp file.

To import a PRO/II keyword input file:  Choosing File/Import from the menu bar. PRO/II displays a list of existing keyword input files.

Figure 3-6: List of Files 

Type or select the name of the keyword file that you want to import.



Click Open or press .

PRO/II converts the selected keyword input file into a flowsheet and displays it in the PFD main window automatically.

Chapter 3


Keyword Features without PRO/II GUI support The RESTART feature is not supported by the graphical user interface in this version of PRO/II. You will not be allowed to import keyword files that contain this feature. If a RESTART keyword is detected upon import, you will be reminded that only the “Run Batch” feature of PRO/II may be used with these keyword input files. See Chapter 10, Running and Viewing a Flowsheet, for information on running keyword files in “Batch” mode.

Keyword Features Imported in “Run-Only” Mode Certain keyword features are not fully supported by the graphical user interface of PRO/II. However, if one of these unsupported features is detected, you will be allowed to import the keyword file, however the GUI interface will operate in the “Run-Only” mode. Such unsupported keywords include: 

BVLE Data



Hydrate Unit Operation



HEXTRAN Property Data Generator.

If you attempt to import a keyword input file that contains PRO/II program features not supported by the graphical user interface, the unsupported features will be automatically listed in a status window. You have the option to save or delete the unsupported features. If you choose to save the unsupported features, PRO/II will run the file in Run-Only Mode.

In “Run-Only” mode, you can: •

Review and modify the PFD graphic image. You may move unit operation icons and streams around to improve the appearance of your PFD.

•

Add drawing elements to the PFD.

•

Add stream property tables to the PFD.

•

Have access to all the capabilities on the Run toolbar (perform all interactive execution functions available on the Run toolbar for both supported/unsupported units, review the calculated results on the PFD for all streams and supported/unsupported units, generate output reports for all features, generate plots for supported features only).

•

Export the flowsheet and stream property table information to other Windows applications.

•

Edit the keyword file, re-import, and rerun (without leaving PRO/II).

•

Use the stream flash icon.


April 2014

In “Run-Only” mode, you cannot: •

View simulation data with the data entry windows. This includes Component and Thermodynamic data. Double-clicking on a unit operation or stream will cause a short warning message to be displayed.

•

Perform any input mode functions, including changing the calculation sequence. All buttons and menu options that access simulation data will be disabled.

•

Perform any of the following functions: adding/deleting units, adding/deleting streams, and reconnecting streams.

•

Export the PRO/II keyword input file.

If you import a keyword file containing unsupported features, one or more messages dialogs appear. These describe the problems and provide options for remedial action. The following display is typical:

Figure 3-7: Typical Unsupported Features Warning Window After responding to each unsupported feature dialog, the message window displays messages similar to the following: ** MESSAGE ** A single STREAM that FEEDS MORE THAN ONE UNIT operation is NOT SUPPORTED by PROVISION. Referencing streams may be used instead. ** MESSAGE ** Duplicate stream 8 feeding X1 is renamed to 8_R1 and is referenced to the first instance of 8. Figure 3-8: Flowsheet Status Window for Unsupported Features

Removing all unsupported features in the dialog boxes allows PRO/II to start normally. However, leaving even one unsupported feature present results in PRO/II operating in “Run-Only” mode. The Title bar of the main PFD window reveals this condition, as illustrated in Figure 3-9.

Chapter 3


Figure 3-8: PRO/II in “Run-only” Mode 

Click Run on the Run menu.

Once the flowsheet solves, you may double-click a unit or stream to view the results.

Exporting Simulation Data to a File PRO/II allows exporting the current simulation flowsheet in a variety of different formats for use in various applications. To begin the export process: 

Choose File/Export… from the menu bar. PRO/II displays the Export window which lists the data export options. Refer to Figure 3-10.

Figure 3-9: Available Data Export Options Note: In the current version, a *.sfd file is generated when the simulation (PFD) is saved and exported. After generation of the *.sfd file, users can restore the PFD layout using the (exported) *.inp file.


April 2014



Choose the Simulation Data to Keyword File option.



Click OK.

PRO/II converts the current simulation flowsheet data into a PRO/II keyword input file in ASCII format. The name of the keyword file will be YYY.INP, where YYY.PR1 is the name of the simulation flowsheet PRO/II database file.

Export Simulation Data to a Keyword File This selection opens a special Save As… dialog window that allows exporting the input data of the simulation to an ".inp" keyword input file. 

Navigate to the destination drive and directory of choice using the Save In: field.



Enter the name of the output file in the File Name: field.



Press the Save button to complete the operation.

The exported keyword file then may be imported into any compatible version of the PRO/II program to rerun the simulation, even on another computer. Keyword files also are a very compact way to archive the data. Note that the keyword file contains all the appropriate data sections (General, Thermodynamics, etc.). In v6.0 and later, the "Simulation Data to Keyword File" option is expanded to include check boxes to control exporting stream and column solution data to the keyword file. If output data exists, even if the solution is unconverged, the two "Include" check boxes are enabled (See figure 3-10). If the Run command was never executed, or not executed since the last time "Restore Input Data" was performed, these checkboxes are disabled. Test for Convergence When the user selects either or both of the "Include" check boxes (Figure 3-10), upon OK, the first thing PRO/II does is test for convergence. If the solution is in an unconverged state, PRO/II displays a message box to warn the user that the data being written to the keyword file is unconverged. Clicking "Yes" continues to the file name selection common dialog. "No" returns the user to the Export window. Note: Beginning with PRO/II version 5.5, exported flowsheets write all unit operations in the flowsheet to the keyword file. Previously, for keyword input files that include a User-Defined Sequence List, only unit operations listed in the Sequence List were exported. This change was necessary to support the new Included/ Excluded functionality. PRO/II now generates a SEQUENCE statement with a list of Available Unit Operations that excludes unit operations marked Excluded at the time of export. Additionally in these instances, PRO/II writes a warning into the keyword file advising that the list of unit operations and the SEQUENCE statement do not

Chapter 3


match. These files may cause input processing problems if read into earlier versions of PRO/II (i.e., versions prior to 5.5).

Exporting the Flowsheet Drawing to the Clipboard You can export part or all of the flowsheet drawing to the Clipboard. You can then paste this drawing into other Windows applications.

To export the entire flowsheet drawing to the Clipboard: 

Choose File/Export from the menu bar. PRO/II displays the Export window (Figure 3-10).



Choose the Flowsheet Drawing option.

 Click OK.

To export one page of the flowsheet to the Clipboard: 

Select the page to export by clicking on its edge on the PFD.






Choose the Selected Page of Flowsheet Drawing option.



Click OK.

Exporting Stream or Unit Property Table Data You can export the information in a stream property table or a unit operation property table to an ASCII file. The file subsequently may be imported into spreadsheet and word processing applications.

To export data from a stream or unit operation property table: 

Select the property table to export (select it on the PFD).






Choose the Stream / Unit Op Property Table option.



Click OK. The Export File Filter window will appear (see Figure 3-11).



Enter a name for the Output File.



Select the desired file format (tab-delimited or comma-delimited) from the Save File as Type drop-down list box.



Click OK.


April 2014

Figure 3-10: Export File Filter Window PRO/II then generates the ASCII file. To import this file into your spreadsheet or word processing program, follow the instructions included with that application.

Exporting Stream Property Table Data to Stream Report Writer You can export the information in a Stream Property Table to a keyword file where it will persist as a Stream Report Writer by using the “Exporting Simulation Data to Keyword File” option. The Property Table name and the specified streams for each table are exported onto an OUTPUT statement and the Property List definition is exported onto a FORMAT statement.

Exporting the PFD to an AutoCAD You can export your flowsheet drawing as an AutoCAD .DXF file: 




Choose one of the following options 

Flowsheet to AutoCAD .DXF



Flowsheet to AutoCAD Design XML



Click OK. The Save As window appears.



Enter a name for the .DXF file.



Click Save to export the data to the file.

Chapter 3


Exporting Tag Data to a File All tagged data in the simulation can be exported to a plain text (ASCII) file for later use in other applications. 




Choose Tag data to file



Click OK. The Save As window appears.



Enter a name for the *.RAW file.



Click Save to export the data to the file.

Exporting Data to Excel Using Spreadsheet Tools Spreadsheet tools are Excel template files and macros that can read information in the PRO/II simulation database to generate reports or perform additional onthe-spot calculations. They can also update data in the simulation database itself using data from an Excel spreadsheet. They offer functionality similar to the export functions described earlier, but export data directly to Microsoft Excel instead of to a disk file. Each Tools/Spreadsheet menu item can be used to start a spreadsheet tool. 

From the Tools menu, choose Spreadsheet. The list of currently installed tools will appear in a side menu.



Click the desired tool to export data and automatically launch Excel.

Note: Microsoft Excel must be installed on your system to use these tools. Additionally, since these tools use macros to export the data, macros must be enabled in Excel. If Excel displays a security dialog, choose “Enable macros”. PRO/II comes pre-installed with some default spreadsheet tools. They can be used to create tables of stream properties, component flow rates, or distillation reports. They also can generate property tables and other reports for a limited number of supported unit operations.

Copying Property Table Data to the Clipboard You can copy the information in a stream or unit operation property table to the clipboard. This table can then be pasted into any other Windows application.

To copy a property table to the Clipboard: 

Select the stream or unit operation property table on the PFD.



Choose Edit/Copy from the menu bar.


April 2014

Copying/Pasting Stream Data in an Excel Sheet Use the buttons labeled Copy / Paste to copy and paste the stream data to and from an Excel sheet. This enables the user to enter and analyze the data with ease. The feature is implemented in all dialog boxes where the data is represented in XY grid. XY grid has the following properties: The grid origin is numbered 0.0. •

The X and Y axis divide the grid into 4 quadrants.

•

Display any grid variable as a distinct value per cell or smoothly varying.

•

No duplicate values are allowed.

Note: Ctrl+C, Ctrl+V, Ctrl+X can be used a shortcut to COPY, PASTE and CUT respectively.

Chapter 3


Chapter 4 Building a Flowsheet This chapter describes how to construct a flowsheet. It begins by describing the various defaults that may apply to your simulation on a global, simulation, or unit level. This chapter also includes instructions for placing unit operations, connecting units, and drawing objects that enhance the presentation of your flowsheet without affecting calculations.

Setting Simulation Preferences PRO/II enables you to set global defaults for problem descriptions information, units of measure and thermodynamic systems. These global defaults apply to all simulations unless you specifically override them either for a particular simulation or unit operation. On a simulation level, you can set problem-specific input and output units of measure defaults. Simulation level settings override global defaults. In addition, you can change units of measure settings for a specific unit. This setting overrides both simulation and global defaults.

Setting Problem Description Global Defaults The Problem Description Information (Project Identifier, Problem Identifier, User Name, Date, and Site) appears on each page of a results printout as a heading and the Problem Description itself appears on the first page. All simulations use the global problem descriptive information unless you override the defaults for a particular simulation.


April 2014

To set problem description global defaults: 

Choose Options/Simulation Defaults from the menu bar.



Choose Problem Description. The Global Default for Problem Descriptive Information window appears, as shown in Figure 4-1.

Figure 4-1: Global Default for Problem Descriptive Information 

Complete the window.



Click OK.

Overriding the Global Default Problem Description Before laying down your flowsheet, you may want to update the problem description for the current simulation. PRO/II uses the global defaults for all simulations, unless you specifically override the data for a particular simulation.

To override the global default problem definition: 

Click Problem Description or choose Input/Problem Description from the menu bar. The Problem Descriptive Information window appears.

You can enter up to ten problem description lines (80 characters each), that will appear on the first page of a results printout.

Setting Units of Measure Global Defaults By default, PRO/II uses the English units of measure set for all input data and for output reports. These defaults apply to all new simulations. You can override the

Chapter 4

Building A Flowsheet 45

default set for either input data or output reports (or both) for all new simulations. PRO/II maintains a library of units of measure sets that you can select from and add to.

To set the unit of measure global defaults: 

Choose Simulation Defaults from the Options menu.

 Choose Units of Measure. The Default Sets of Units of Measure window appears.

Figure 4-2: Global Units of Measure Sets 

Select the desired default units of measure set for entering simulation data. The default choice is ENGLISH-SET1, i.e., the data input will be in English units.



Select the desired default units of measure set for generating the first output report. The default choice is Same as Input, i.e., the first output report will be printed in the default English units.

If any choice other than the default is selected, the second output report will no longer be available, and the list-box for selecting the alternate units of measure set for the second output report will be disabled. Select the desired default units of measure set for generating the second output report. The default choice is None, i.e., no second output report in alternate units will be generated.

Changing Global Units of Measure for One Simulation PRO/II sets English units as the default for units of measure. You can override this default, setting the global units of measure for all new simulations. In addition, you can override the default units of measure for a particular simulation problem.


April 2014

To set the units of measure for the current simulation: 

Click Input Units of Measure or choose Input/Units of Measure from the menu bar. The Default Units of Measure for Problem Data Input window appears.

Figure 4-3: Default Units of Measure for Problem Data Input Window 

Select different dimensional units for data input for each individual category or choose Initialize from UOM Library... to automatically fill in the defaults from another set.



Click Standard Vapor Conditions... to enter the Problem Standard Vapor Condition window. The default temperature and pressure basis are shown in the data entry fields and may be replaced or the standard vapor volume per mole may be replaced, not both. PRO/II default values are:



Note in the following table that standard conditions for liquid molar volume are different than standard vapor conditions. Table 1: Standard Conditions

Temperature English

Chapter 4

60

° F

Pressure 14.696 psia

Vapor Volume 3

379.48 ft /lb-mol

Liquid Mole Volume 77F


Metric

0°C

1.0332 2 kg/cm

22.414 m /kg-mol

SI

273.15 K

101.32 kPa

22.414 m /kg-mol

3

25C

3

298.15K

The current atmospheric pressure (Pressure Gauge Basis) is shown in a data entry field and may be replaced with another value as desired. The PRO/II default value is 14.696 psia or the metric equivalent. 



Click TVP and RVP Conditions... to select the Problem TVP and RVP Conditions window. The temperature for true vapor pressure specifications may be replaced in this window. The PRO/II default for TVP calculations is 10 ° F. The ca lcula tion m pressure may be selected in a drop-down list box on this window. Choices are: 

API Naphtha (the default)



API Crude



ASTM D323-73



ASTM D323-82



ASTM D4593-91



ASTM D5191-91



ASTM D323-94

Click OK.

Units of Measure Library A library of dimensional unit sets which may be used for data entry or report writing is maintained with this feature. To add a new set to the library or to edit an existing set: 

Select Options/Units of Measure List from the menu bar.

The Units of Measure Library window appears and may be used to create, copy, edit, rename, and delete dimensional unit sets. The Units of Measure Set Name and Description list box contains the names of the dimensional unit sets currently in the library. The program provides three initial dimensional unit sets: English (the default), Metric, and SI.

To create a new set: 

Click Create... on the Units of Measure Library window to get the Create Units of Measure Set window.


April 2014

Figure 4-4: Units of Measure Library 

Enter a name for the new set in the data entry field provided, and select the basis for the set with the appropriate radio button: English, Metric, or SI.

Figure 4-5: Create Units of Measure Set Window 

Click OK to continue.

The units for the standard dimensional unit sets in PRO/II are assigned to the new set and the edit feature may be used to customize the set. Note: An alternate way to create a new set is to highlight an existing set in the Units of Measure Set Name and Description list box and click Copy on the Units

Chapter 4


of Measure Library window. The name for the new set is then entered in the Copy Units of Measure Set window. The Edit feature may be used to customize the set.

To delete, rename or edit a set: 

Select the set in the Units of Measure Set Name and Description list box.



Click the Delete, Rename, or Edit button on the Units of Measure Library window.

Editing the Dimensional Unit Sets for Output Reports A dimensional unit set for output reports may be edited in two places in PRO/II: 1. Library sets are edited with the Edit... feature in the Units of Measure Library window. 2. The set being used for the current problem is edited in the Default Units of Measure of the Problem Output Report which is accessible from the PFD main window by: 

Selecting the Output menu on the menu bar.



Selecting the Report Format from the Output menu.

 Selecting Units of Measure from the Report Format menu. Editing of the dimensional items is identical for these two windows. The dimensional unit set for the output report is initialized from the global set, as previously explained. However, a different set may be chosen from the units of measure library while in the Default Units of Measure for Problem Output Report window. To use a different dimensional unit set: 

Click Initialize from UOM Library... The Initialize Units of Measure from UOM Library window appears.



Select the desired set from the drop-down list box.



Click OK to continue. This set now becomes the output report set. The newly selected output report set may be edited in this window as desired. The edited set is saved with the problem.

The Print Option for output reports may also be selected using the Output Report(s) to be Printed drop-down list box where options are: One Output Report in Input Units (the default): When this option is selected, an output report based on the units of measure used for the problem data input will be generated. The currently specified input units of measure will be displayed for informational purposes, but they cannot be changed. With this


April 2014

option, the output units of measure can only be changed by selecting the Units of Measure option from the Input menu. One Output Report in Output Units: When this option is selected, an output report based on the output units of measure specified will be generated. The currently specified output units of measure will be displayed, and they can be changed if desired. Two Output Reports, one in Input Units, one in Output Units: When this option is selected, two output reports will be generated, one each, based on the input and specified output units of measure will be generated. The currently specified output units of measure will be displayed, and they can be changed if desired. For the second and third cases discussed above, the displayed output units of measure set can be copied from the specified input units, or initialized from one of the units of measure sets stored in the units of measure library. To copy the input units of measure set to be used for the output report, or to reset the explicitly specified output units to the previously specified input units: 

Click Copy from Input UOM on the Default Units of Measure for Problem Output Report window.




To initialize the output units of measure set from a units of measure set stored in the units of measure library: 

Click Initialize from UOM Library... on the Default Units of Measure for Problem Output Report window.




If the results of a previously executed simulation must be printed in a different set of dimensional units, it is only necessary to select the required units through this feature and generate a new report. The entire simulation need not be executed from the start just to obtain the output results in a different set of dimensional units.

Chapter 4


Setting Thermodynamic System Global Defaults To set the thermodynamic system global defaults: 

Choose Simulation Defaults from the Options menu.



Choose Thermodynamic System. The Global Default Thermodynamic System window appears.

Figure 4-6: Global Default Thermodynamic System Window 

Complete the window.



Click OK.

Note: This global default will not become effective until the next time File/New is selected.

Setting General Drawing Defaults PRO/II allows you to change the appearance of your workplace through the General Drawing Defaults window. You can set the snap and move tolerances, zoom and pan increments, the PFD palette icon, icon fill, unit snapping, and delete confirmation. The defaults, shown below in Figure 4-7, are appropriate for most scenarios and you may never need to make changes in this window.


April 2014

To make changes to the general drawing defaults: 

Choose Options/Drawing Defaults/General... from the menu bar.

Figure 4-7: General Drawing Defaults Window

Changing Delete Confirmation By default, PRO/II prompts you to confirm each delete operation. You may want to change this default setting.

To turn delete confirmation off: 

Within the General Drawing Defaults window, uncheck Confirm Deletes to turn the option off.

Setting Global Flowsheet Tolerances Use this option to identify the acceptable margins of error and criteria for satisfying certain numerical methods. Some flowsheet tolerances, such as the tolerance for flash calculations, are internal and are not user-definable. The default flowsheet tolerances are satisfactory for most problems.

To set the tolerance for this flowsheet: 

Choose Input/Flowsheet Tolerances on the menu bar to open the Tolerances dialog.

Chapter 4


Figure 4-8: Default Unit Specification Tolerances

Placing a Unit on the Flowsheet The PRO/II main window is your drawing board. PRO/II supplies a floating PFD palette and drawing objects that help you draw your problem quickly. The PFD palette shows icons for each unit operation that you can select to place on the flowsheet. The PFD palette appears automatically when you open a new or existing file, or when you import a keyword file.

To close or open the PFD palette: 

Click Palette on/off , or select the View menu on the main PRO/II window. Check the Palettes/PFD option on or off.


April 2014

Selecting a Unit from the PFD Palette To select a unit icon and place it on your flowsheet: 

Choose the icon from the PFD palette (see Chapter 9 for unit descriptions).



Position the cursor where you want the unit icon to appear and click the left mouse button.

Figure 4-9: Placing a Unit

Snapping When connecting two units with a stream PRO/II will adjust or “snap” the unit icon positions to straighten the connecting stream. By default, units you add to or move in the PFD main window snap to an invisible grid. You can turn grid snapping off.

Chapter 4


To turn grid snapping off: 

Choose Drawing Defaults from the Options menu.



Select General.



Select Unit Snapping. The box.

dis a ppe a rs from the Unit Snapping check

Placing Multiple Unit Icons You can place a series of unit icons in succession.

To place more than one unit at a time: 

Select the desired unit from the floating PFD palette.



Press , and while holding down , click on the PFD main window to place the icon.



While still holding down click on the PFD main window to place the second icon.



Repeat for each additional placement of this icon.

Canceling Unit Placement

To cancel unit placement: 

Click the right mouse button.

Deleting a Unit

To delete a unit already on the flowsheet: 

Click on the unit icon you want to delete.



Click delete on the toolbar, or press , or click the right mouse button and select Delete.

Re-labeling a Unit PRO/II software automatically labels each unit icon you place on the PFD main window. You can change the label for a unit by modifying the label on its data entry window or by clicking Find & Rename Units on the View menu. By default, the label consists of a character and a one-digit auto incrementing number.


April 2014

To re-label a specific unit: 

Double-click on the unit you want to rename. The data entry window for that unit appears.

Figure 4-10: Unit Data Entry Window 

Type over the default name for Unit.



Click OK.

Also, you can rename one or more units through Find & Rename Units window. 

Click Find & Rename Units on the View menu. The Find & Rename Units window appears.



In the Rename field, enter the new name of the unit.



Click Preview to see the changes.



Click Apply or OK to apply the changes.

Drawing Streams Streams mode is used to lay out the connections between units and feed and product streams. The product ports for each unit automatically appear when you

Chapter 4


depress the Streams button. Required product ports are red, while optional product ports are green. For some unit operations, an entire side of the unit will be red or green denoting multiple connections to that port.

To use the Streams mode or display ports: 

Select Streams

on the PFD palette.

Figure 4-11: Streams Button Down The cursor changes to an arrow with a small S to indicate Streams mode. PRO/II displays the product ports for each unit in the layout. To display feed ports, depress the left mouse button while the Streams button is depressed.

To draw a feed stream: 

Click on an unoccupied area of the PFD main window.



Click the mouse on the feed port you want the incoming stream connected to.

To draw a product stream: 

Click the left mouse button on a product port.



Click the left mouse button again where you want the stream to end.


April 2014

Drawing a Connection To connect units: 

Click the left mouse button on a port to anchor or start a stream. The ports and port colors for some unit operations change depending on the port you selected.



Click the mouse again at the other unit you want to connect. PRO/II draws an orthogonal line to connect the ports.

Figure 4-12: Feed, Product, and Connection Streams Layout

Canceling a Connection To cancel a stream connection: 

Click the right mouse button or press .

Chapter 4


Changing a Connection To change a connection: 

Click the end (port) of the stream and hold down the mouse button.



Drag the end of the stream to a new port.



Release the mouse button.

Connecting Streams When One Unit is Not Visible In order to complete a stream connection, the ending unit for the stream segment must be visible in the PFD main window. You may open another viewport window of the same simulation and move to the end port you wish to view. Alternately, you can also use the scroll bars, the Pan View window, Search for Unit, or Search for Stream tool to display the end port.

Labeling a Stream PRO/II software automatically labels each stream you place on the PFD main window. By default, the label consists of an S followed by an auto incrementing number. You can change the label of a stream by changing it on its data entry window or on the Find and Rename Streams window.

To re-label a stream: 

Double-click the stream you want to re-label. The Stream Data window appears.



Type over the default name for Stream.



Choose OK.

This stream will now show the new label; other streams retain the original labeling scheme. Also, you can rename one or more streams through Find & Rename Streams window.    

Click Find & Rename Streams on the View menu. The Find & Rename Streams window appears. In the Rename field, enter the new name of the stream. Click Preview to see the changes. Click Apply or OK to apply the changes.


April 2014

Moving Streams You can change the route of the stream between two connections whenever you wish.

To move a stream: 

Click and hold the left mouse button at an end of the stream you want to move.



Drag the stream to the new location.



Release the mouse button to drop the stream in place.

Rerouting Streams As you add new connections, PRO/II automatically performs a stream route calculation. When you move a stream or a unit operation icon, this calculation may no longer be valid. You can recalculate an unobstructed, orthogonal path for selected streams.

To reroute a stream: 

Select the stream(s) you want to reroute.



Choose Reroute from the Edit menu.

PRO/II calculates the best route for these streams and automatically reroutes them.

Searching for a Unit or Stream PRO/II builds two lists that identify the units and streams you have placed on the flowsheet. The Unit List identifies each unit by name. The Stream List identifies each stream by name.

To search for a unit: 



Click or click Find & Rename Units on the View menu. The Find & Rename Units window appears, showing the names of all the units currently placed on the flowsheet diagram. Select the unit you want to go to. The unit appears at the center of the PRO/II main window.

Chapter 4


To search for a stream: 



Click or click Find & Rename streams on the View menu. The Find & Rename Streams window appears, showing the names of all the streams currently placed on the flow diagram. Select the stream you want to go to. The stream appears at the center of the PFD.

Note: These search tools are only available on the toolbar if the Standard Toolbar is active.

Drawing Freehand Objects PRO/II provides six objects that you can place on the flow diagram, to customize the look and increase understanding of the flow diagram without interfering with simulation data. These objects are: 

Text



Line



Polygon



Rectangle



Ellipse



Page

Entering Text You use the text option to include notes on your drawing. Once you choose text mode, you remain in text mode as long as you continue to choose the OK or Cancel button on the Draw Text window; choosing Cancel exits text mode.

To place text: 

Choose Draw/Text from the menu bar.


April 2014

Figure 4-13: Draw Text Window 

Enter the text you want to appear on the diagram.



Optionally, choose a font size for the text. The default is 50 pixels.



Choose OK.

Drawing Lines You use the line option to add connected lines to the diagram without interfering with simulation data. PRO/II provides an orthogonal poly-line feature.

To draw a line: 

Choose Line from the Draw menu.



Click and hold the mouse button on the PFD main window to anchor the line.



Press to set each anchor point for drawing in a new direction.



Release the mouse button to complete your line.

To draw orthogonal connected lines: 

Choose Line from the Draw menu.



Click and hold the mouse button on the PFD main window to anchor the line.



Press and hold , and while holding down , drag the cursor.



Press to set each anchor point for drawing in a new direction.



Release the mouse button to complete.

Chapter 4


Drawing Shapes You can draw shapes to enclose figures on a diagram without interfering with simulation data.

To draw a polygon: 

Choose Polygon from the Draw menu.



Click and hold down the mouse button on the PFD main window.



Press to each anchor point for drawing in a new direction.



Release the mouse button to complete your object.

To draw an orthogonal polygon: 

Choose Polygon from the Draw menu.



Click and hold the mouse button on the PFD main window.



Press and hold , and while holding down , drag the cursor.



Press to each anchor point for drawing in a new direction.



Release the mouse button to complete your orthogonal polygon.

To draw a rectangle or ellipse: 

Choose Rectangle or Ellipse from the Draw menu.






Drag and release when you see the desired size rectangle.

To draw a square or circle: 

Choose Rectangle or Ellipse from the Draw menu.






Press then drag and release the mouse button to complete your square.

Drawing Pages You can divide your PFD into “pages” and define separate page setup options for each page. Pages can be individually printed or copied to the clipboard (see Chapter 3, Managing PFD Files).

To add a page: 

Choose Page from the Draw menu.


April 2014



Click on the PFD.



Drag and release the mouse button to the desired size.

The page name is automatically given as PG followed by an auto incrementing three-digit number.

Figure 4-14: Pages

To change the page setup options: 

Double-click anywhere along the page border. This brings up the Page Setup window.



Select your page setup options.




After you have set up a page, you can resize it or make this page one cell in a grid of pages.

To resize the page: 

Click near the page outline to highlight the page.



Click and drag the sizing box.

Chapter 4


To move the page: 

Click and drag the page outline to a new location.

To make a grid of pages: 

Select the page by clicking near the page outline.



Double-click the left mouse button to display the Page Setup window.



Click on the radio button labeled Grid in the Change Page Parameters group box.



In the Page/Grid group box, select the radio button for Multiple Pages.



Change the number of rows and columns to make a grid of pages on the PFD. The page you started with will be the upper left cell of the grid.

The grid can be resized and moved on the PFD in the same manner as a single page.


April 2014

Chapter 5 Manipulating Objects This chapter describes how to select unit icons, streams, and other objects on the PFD main window and how to move, resize, rotate, or flip them. In addition, this chapter describes how to edit and align text.

Selecting Objects or Groups of Objects You can select a single object, multiple (noncontiguous) objects, or a group of objects. Objects or groups of objects include units, streams and drawn objects. All manipulations (delete, rotate, move) are performed on selected objects.

Selecting Multiple Objects You can select a set of noncontiguous objects.

To select a set of individual objects: 

Click on the first object.



Press .



While holding down , click on each object you want to include as part of this set.

Figure 5-1: Multiple Unit Selection Handles Handles appear for the set of objects. For example, although five objects appear to be selected as part of this set (Figure 5-1), when you move the selection, the

Chapter 5

Manipulating Objects 67

fourth and fifth objects (the valve and the compressor) do not move with the set (Figure 5-2).

Figure 5-2: Move Multiple Objects

Selecting a Group of Objects You can gather a group of contiguous objects by dragging a selection rectangle around them.

To select a contiguous group of objects: 

Click on an unoccupied area of the PFD adjacent to one of the items you want to select and begin dragging the cursor by moving your mouse.



Drag the cursor until all desired objects are inside the selection rectangle outline.



Release the mouse button to end the selection.



Handles appear for the selected group of objects.

Selecting All Objects You can select all objects on the flowsheet with one command. Once selected, you can then move or delete the entire selection.


April 2014

To select all objects on the flowsheet: 

Choose Select All from the Edit menu.

Deselecting Objects If you change your mind after selecting objects, you can reverse any selection. To deselect or unselect all objects in the layout, do one of the following: 

Choose Select None from the Edit menu.



Click on another item or on an unoccupied area of the PFD.

Resizing Objects You can change the height, width, or overall size of any object or a group of objects on your flowsheet.

Changing the Size of a Selected Object When changing the width of a group of objects, you change the absolute distance between the objects and maintain the relative distance. To change the size of an object: 

Click and drag the cursor until the object is the desired size.




Chapter 5


Figure 5-3: Resize Column Note: Condensers and reboilers shown on distillation or side columns are fixed in size. They do not resize when you change the size of the column.

Restoring Unit Icon Size If you don’t like how your resized icon looks (relative to other icons and objects on your flowsheet) you can quickly return the icon to its default size. To restore an icon to its original size: 

Choose Restore Icon Size from the Edit menu. You can also click the right mouse button on a selected icon, and then choose Restore Icon Size from the Icon pop-up menu.

Rearranging Objects or Groups of Objects You can move objects to a different area of the flowsheet. You can also rotate or flip a unit icon so it fits into the flow of your diagram.

Moving Selected Objects You can move an object to a new position on the flowsheet.


April 2014

To move a selected object: 

Click and drag the object or group of objects to a new position.




Setting Move Tolerance Move Tolerance controls the incremental distance for any object you move. The default is 5 pixels. To change move tolerance: 

Choose Drawing Defaults from the Options menu, then General.

The General Drawing Defaults window appears. 

Type the desired value over the default Move Tolerance.



Choose OK.

Rotating Selected Objects You can rotate a selected object(s) on its axis by 90, 180 or 270 degrees. To rotate a selected object: 

Choose Rotate from the Edit menu. The Rotate degrees cascade menu appears to the right of the Edit menu.



Choose 90, 180, or 270.

Rotating an Icon You can also click the right mouse button on a unit icon, and then choose Rotate from the Pop-up Unit menu to display the rotation degrees.

Flipping Selected Objects You can flip a selected object(s) horizontally or vertically to better orient the object(s) relative to other objects of the diagram. To flip a selected object: 

Select an object(s).



Choose Flip from the Edit menu. The Flip options menu appears to the right of the Edit menu.



Choose Horizontal or Vertical.

Flipping an Icon You can also click the right mouse button on a unit icon, and then choose Flip from the Pop-up Unit menu to display the flip options.

Chapter 5


Editing Text You can change the text, size and or rotation of any text object you placed on the PFD main window. To edit text: 

Double-click on the text object you want to change. The Draw Text window appears.



Edit as desired and choose OK.

Aligning Text You can align text in two or more text boxes to the left, right or center of the box they are drawn in. To align text: 

Select the text you want to align (you must select at least two) by clicking on the first text box, then click other boxes while holding down the key.



Choose Align Text from the Edit menu. The align menu pop-up appears to the right of the Edit menu.



Choose Left, Center or Right.


April 2014

Chapter 6 Viewing Flowsheet Contents PRO/II offers a variety of tools that aid you in viewing your flowsheet contents: 

Horizontal and vertical scroll bars allow you to change the visible portion of the process flow diagram in the PFD main window.



You may open additional viewport windows of your current flowsheet to display different views of your simulation.

 The Pan View window is a special feature of PRO/II that enables you to see a thumbnail of the entire flowsheet and use a bounding box in the thumbnail to move the visible area. This chapter describes how to use the PRO/II scroll, pan, and multiple viewport features to display portions of your flowsheet diagram in the PFD.

Scrolling the PFD You can scroll the PFD left, right, up, or down using the horizontal and vertical Scroll Bars. Both bars enable you to scroll in small or large increments or to scroll to a general location.

Setting Scrolling Increments You can change the actual value for the scroll increments by altering the Pan Increment value on the General Drawing Defaults window.

Zooming You can access the PRO/II zoom features from the View menu, using the zoom buttons on the toolbar, or using the keyboard. To zoom in or out, do one of the following: 

Click



Choose Zoom In or Zoom Out from the View menu.



Choose or to Zoom in or Zoom out the PFD.

on the toolbar.

Zooming in on a Selected Area You can specify the exact area of the flowsheet that you want to zoom in on.

Chapter 6

Viewing Flowsheet Contents 73

To zoom in on a specific area of the flowsheet: 

Click



Click and drag the mouse to encompass the desired area within the selection rectangle outline.



Release to complete the zoom area operation. The selected area fills the PFD.

on the toolbar or choose Zoom Area from the View menu.

Zooming to Show the Full Flowsheet You can quickly display the entire flowsheet in the PFD. To use zoom to show the full flowsheet, do one of the following: 

Click



Choose Zoom Full from the View menu.



Press .

on the toolbar.

Setting the Zoom Increment You can change the increment PRO/II uses to zoom in or zoom out within the General Drawing Defaults window. The default small zoom increment is 5 pixels and the default large zoom increment is 20 pixels.


April 2014

Opening Multiple Viewport Windows You can open multiple viewports of a single simulation problem to display different views of the flowsheet. To open an additional viewport of the current simulation problem, do one of the following: 

Click Multiple Viewports Window menu.

on the toolbar or choose New View on the

Note: If the multiple viewports button is not displayed on your toolbar, check the Standard menu option from the View/Toolbar menu.

Figure 6-1: Multiple Viewports

Redrawing the Simulation You can use redraw to clear extraneous lines and dots from the PFD.

Chapter 6


To redraw the diagram, do one of the following: 

Click



Choose Redraw on the View menu.



Press .

on the toolbar.

Panning You can pan the contents of the PRO/II main window using the Pan window or the Small Pan or Large Pan options on the View menu. The Pan View window is a thumbprint of the entire flowsheet. A bounding box identifies the area of the flowsheet currently visible in the PFD main window. You move the bounding box or change its size to change how much or what portion of the flowsheet you see in the PFD. From the View menu, you can pan in large or small increments: up, down, left, or right. You can change the settings for the pan increment in the General Drawing Defaults window.


April 2014

Displaying and Hiding the Pan View Window To display the Pan View window: 

Click

on the toolbar or choose Pan View from the Window menu.

Figure 6-2: Pan View Window

Panning - Using the Pan View Window Use the bounding box to change the visible portion of the flowsheet in the PFD window by moving, enlarging or reducing the bounding box in the Pan View window. The flowsheet in the PFD view changes to match the area encompassed by the bounding box.

Moving the Bounding Box To move the bounding box: 

Click the mouse inside the box.



Drag to a new location. The area enclosed fills the PFD.

Note: For a large flowsheet, use the Pan View window to quickly switch from one area of the flowsheet to another.

Chapter 6


Changing the Size of the Bounding Box To change the size of the bounding box: 

Click and drag the bounding box border handle to enlarge or reduce the bounding box. The area enclosed fills the PFD.

Panning - Using the Menu Options You can pan the image in the PFD up, down, left, or right using the panning options on the Zoom menu. To pan the image a large or small amount: 

Choose Large Pan or Small Pan from the View menu. The pop-up menu appears.



Choose Left, Right, Up, or Down.

Setting Panning Sensitivity You can change the increment PRO/II uses to pan. The default small pan increment is 5 pixels and the default large pan increment is 20 pixels.


April 2014

Chapter 7 Data Entry Windows PRO/II offers a wide variety of data entry windows for entering the data associated with your PRO/II simulation. There are a number of libraries from which you can extract sets of data. This chapter provides an introduction to these data entry windows.

Defining the Simulation You can use the data entry window buttons on the toolbar or the options on the Input menu to define the scope of the current simulation. PRO/II identifies which units are missing data by putting a red border around the unit icon (on the toolbar). For units that are missing product streams, the identification string for that unit appears in red (on the PRO/II main window). Defining the scope of the simulation involves: 

Defining the simulation problem



Selecting the components for the simulation



Setting the thermodynamic methods for the simulation

Note: Chapter 8, Specifying Component, Thermodynamic and Stream Data, and Chapter 9, Unit Operations and Utility Modules, provide explicit details on the use of the data entry windows introduced in this chapter. A summary of the Data Entry Window buttons available on the PRO/II toolbar is provided below. Button

Chapter 7

Menu Item

Description

Problem Description

Enables you to describe the current simulation and relate it to a specific project.

Units of Measure

Enables you to set units of measure specific to this simulation. Each new simulation extracts defaults from the default Unit of Measure Set.

Component Selection

Enables you to specify the components and pseudo-components you want to use in the current simulation

Component Properties

Enables you to supply component properties.

Data Entry WIndows 79

Thermodynamic Data

Enables you to select thermodynamic methods for the current simulation.

Assay Characterization

Enables you to modify TBP cut points and characterization options for the generation of pseudo-components from Assay streams.

Procedure Data

Enables you to supply FORTRAN code for kinetic reaction rate calculations without the need for compilation and linking.

Case Study Specification

Allows you to perform studies on a base case solution by altering parameters selectively and rerunning.

Reaction Data

Enables you to define reactions and provide heat of reaction, equilibrium, or kinetic data for reaction sets.

Calculation Sequence

Enables you to specify a user-defined calculation sequence.

Recycle Convergence

Enables you to specify user-defined recycle convergence and acceleration options.

Selecting Components Use this option to select the components and pseudo-components that you want to include in this simulation.

To select components for use in this simulation: 

Click on the toolbar or choose Component Selection on the Input menu. The Component Selection window appears.


April 2014

Figure 7-1: Component Selection 

Select a component from the available lists or type the name of the component. Each component you select appears in the List of Selected Components box on the right side of the window.

Modifying Component Properties You can use this option to modify fixed component properties or use the Fill from Structures feature to fill in missing component data for library or user-defined components. To modify component properties: 

on the toolbar or choose Component Properties from the Input Click menu. The Component Property Modification window appears.

Chapter 7


Figure 7-2: Component Property Modification

Selecting Thermodynamic Methods You use the thermodynamic data option to choose the thermodynamic method(s) for this simulation.


April 2014

To set thermodynamic calculation methods for this simulation: 

Click menu.

on the toolbar or choose Thermodynamic Data on the Input

Figure 7-3: Thermodynamic Data You can specify a predefined system of thermodynamic calculation methods. 

Select a category of predefined systems. PRO/II displays the predefined systems for this category in the Primary Method list box.



Select a predefined system from the Primary Method list box.



Choose Add-> to define the calculation method.

Chapter 7


Selecting Assay Data You use this option to modify the data obtained from the selected Assay Set. To select assay data for this simulation: 

Click menu.

on the toolbar or choose Assay Characterization on the Input

Figure 7-4: Assay Cut points and Characterization PRO/II always supplies the Primary TBP cut point set. You can modify the primary set or define a new cut point set or set characterization options.

Specifying Reaction Data You use this option to define reactions and enter heat of reaction, equilibrium, or kinetic data for reaction data sets. To specify reaction data sets for this simulation: 

Click on the toolbar, or choose Reaction Data on the Input menu to open the main Reaction Data window.


April 2014



Add a new Reaction Set Name or highlight an existing one.



If desired, enter an optional description.

Figure 7-5: Main Reaction Set Window 

Click the Enter Data… button to open the Reaction Definitions dialog.

Figure 7-6: Reaction Definitions Dialog

Chapter 7


Specifying Reaction Procedure Data Use this option to create procedure blocks to calculate kinetic reaction rates. You are able to supply FORTRAN code for the reaction rate calculations without the need for compilation and linking. To select procedure data for this simulation: 

Click

on the toolbar or choose Procedure Data on the Input menu.

Figure 7-7: Main Procedure Data Window 

Click a number at the left of a line to select an existing procedure or to add a new one.



If desired, enter an optional description.



Click the Enter Data… button at the right end of the line to open the Kinetic Procedure – Definition dialog. Write the code for performing the Kinetic calculations in this dialog.



Click OK to save the procedure and exit the dialog.

Specifying Multiple Simulations for Case Study Use this option to make changes to input data and then examine the effect of those changes on the values of calculated data or functions of calculated data. To select case study data for this simulation: 

Click menu.



Check the Define Case Study box.

on the toolbar or choose Case Study Data from the Input


April 2014

Figure 7-8: Case Study Specification Dialog

Setting the Problem Calculation Sequence PRO/II performs a simulation by solving one unit operation at a time, following a certain calculation sequence to reach the problem solution. Use this option to specify the method to determine this calculation sequence for the current problem.

Chapter 7




To select calculation sequence for this simulation, Click on the toolbar or choose Calculation Sequence from the Input menu.

Figure 7-9: Calculation Sequence Dialog 

If required, select a different Sequence Method.



To exclude a unit operation from the calculations, clear its corresponding check box in the Sequence map.


April 2014



To include an excluded unit operation, select its corresponding check box in the sequence map.



To see the included or excluded units, select one of the following options in the Show Units list box: All Units, Excluded Units, and Included Units.



To expand or collapse the the loops and unit operations tree in the Sequence map, click one of the following buttons:

.



To search a unit operation in the Sequence map, type the full or partial name of the unit operation in the Search box.



To navigate through the Sequence map, use the following buttons: .



To search a unit operation by typing the initial part of its name, select the following check box:

.

Note: If there are any crossings among the recycle or control loops, they are highlighted in red color in the Sequence map.

Specifying Recycle Convergence You use this option to override the recycle loop sequence determined by PRO/II, and to specify acceleration methods and convergence tolerances for individual loops. Note: This window is not available if you select the SIMSCI method for Calculation Sequencing, since the loops are determined automatically by this method. To select recycle convergence for this simulation: 

Click menu.

Chapter 7

on the toolbar or choose Recycle Convergence on the Input


Figure 7-10: Recycle Convergence Options

Data Entry Windows for Unit Operations The data entry window for any unit operation can be accessed by highlighting the unit on the PFD and selecting the Input/Data Entry from the menu bar. Numerous types of data entry devices are used to supply numeric values and select calculation options in PRO/II, including: Push Buttons, Radio Buttons, Check Boxes, Edit Fields, Spin Buttons, Standard List Boxes, Drop-Down List Boxes, Grid and X-Y Grid, Combo Boxes, DropDown Combo Boxes, Linked Text and Notes.


April 2014

Most main data entry windows provide Help, Overview, and Status buttons that enable you to access different levels of help text. In addition, some main data entry windows (and some subordinate windows) provide UOM, Define and Range buttons. Grayed buttons indicate that the feature is currently unavailable. Button

Description Displays context-sensitive help for the active data entry field or for the window itself (if there is no active field). Displays the main help window for the data entry window. Displays the results of the data consistency checks performed for the main window after you choose OK. Selects a unit of measure set for the selected data entry field. References one stream or unit parameter value to another stream or unit parameter. Displays the valid range of values for the active data entry field. Displays the notes, associated with the unit.

Grids and the X-Y Grid Grids are used to supply data in tabular form. There may be several rows of related data entries. An X-Y Grid is a special type of grid that is used to supply data for relational curves. The two-grid columns contain an independent variable (x) and one related dependent variable (y). The Column Tray Hydraulics window shown below is an example of a grid. Notice that it provides columns for the starting tray number, ending tray number, calculation type, and entry of tray data. Each row has a numbered click button which is used to select the row for toolbar actions. For this example, several types of data entry devices are used in the grid.

Chapter 7


The starting and ending tray numbers are integer edit fields, the calculation type is a drop-down list box, and the entry of tray data is a click button, which brings up the Column Tray Sizing window or Column Tray Rating window, depending on the calculation type that was selected.

Figure 7-11: Column Tray Hydraulics Window Observe that four rows are provided in the initial grid corresponding to five sections in the column. This may be expanded by clicking a row number button and then clicking the Insert button. A row will be added below the selected row. When the number of rows exceeds five, a scroll bar appears at the right side of the grid to provide access to the rows not displayed. To deselect a row, click the number button of the previously selected row, or select a different row. To clear data entries from a row, click the row number button and then click Reset. To remove a row, click the row number button and the Cut button.


April 2014

As another example, the Compressor Outlet Pressure Performance window shown below contains an X-Y grid for a user-supplied compressor pressure curve.

Figure 7-12: Compressor Outlet Pressure Performance Window Notice that two columns are used for the pressure curve. The first column is the volumetric feed rate and the second column is the corresponding outlet pressure from the compressor. Four individual entries or cells corresponding to two rows in the table are marked with a red border as mandatory input. Optionally, more pairs of information may be provided. The initial grid displays four pairs of cells. Note that each row in the grid has a numbered click button which may be used to select the row. The initial table may be expanded with the Insert button on the toolbar as described in the previous example. When the number of rows in the X-Y grid exceeds four, a scroll bar appears to provide access to rows not displayed. A row may be deleted from the grid by clicking its number button and then clicking Cut. To copy a row, first click its number button and then click Copy. The row is copied into the clipboard. Next, click the row number button for the row which will be just below the copied row. Complete the copy by clicking Paste to insert a copy of the row from the clipboard.

Linked text Linked text is used to input information in a sentence format. Numeric values, mathematical operators, stream or unit names, or various options may be

Chapter 7


supplied as linked text. Linked text may serve to access another data entry device. The Feedback Controller data entry window containing linked text is shown in Figure 7-12.

Figure 7-13: Feedback Controller Main Data Entry Window - Initial Display Linked text is used on this window to define the Specification and Variable. Parameter and Value texts in red require you to click them and provide data. The text string the default tolerance is green, denoting a default value. Optionally, a different tolerance may be provided by clicking the afore-mentioned text string to open the Specification Tolerance window, where the appropriate radio button may be clicked to select a new tolerance type, i.e., relative tolerance. Click OK to return to the Feedback Controller window. Notice the relative tolerance text string turns blue, to indicate a user-supplied value. When the value text string is clicked, a floating point entry field for the specification value is displayed with a red border signifying mandatory input. The value you supply is now displayed in blue numbers instead of the value text string.


April 2014

Clicking the Parameter text string retrieves the Parameter window in which the unit or stream and its parameter are defined. The unit or stream identifier and the parameter for the specification are now displayed in blue, replacing the Parameter text string.

Figure 7-14: Feedback Controller Data Entry Window - Final Display

Chapter 7


Chapter 8 Specifying Component, Thermodynamic and Stream Data This chapter describes several types of optional component, thermodynamic and stream information which may be supplied for PRO/II. In many cases, the default values are satisfactory and it may not be necessary for you to visit these sections.

Component Data General Information PRO/II provides considerable flexibility in the definition of component data. No limit is set on the number of components which may be used for any problem. Furthermore, component data may originate from a variety of sources such as SIMSCI databanks, user-prepared databanks, user-defined components, and components derived from petroleum assay data for feed streams. Moreover, you may stipulate a preferential search order when multiple databanks are used. The SIMSCI databanks, SIMSCI and PROCESS, contain more than 1700 components and are adequate for nearly all simulation models. The AIChE DIPPR databank is also available as an add-on to PRO/II. User databanks of thermo-physical data can be created, using SIMSCI LIBMGR and the Thermodynamic Data Manager (TDM) programs, and maintained through PRO/II graphical user interface. SIMSCI REGRESS is fully supported in TDM and PRO/II, and provides the capability of regressing experimental thermo-physical data to fit model equations.

Selecting Library Components You may select library components, from both SIMSCI and user-supplied databanks, through the Component Selection main data entry window. To open this window from the PRO/II main window: 

on the toolbar, or select the menu bar item Input/Component Click Selection. The Component Selection window appears.

If you know the library access name for a component, you may enter it directly into the data entry field. Click Add-> or press to retrieve the component


April 2014

from the component databank and add it to the List of Selected Components. If the component cannot be located by the name you have entered, a warning will recommend that you use the Select from Lists… feature to locate the component in the SIMSCI and PROCESS databanks: 

Click Select from Lists… on the Component Selection main data entry window to open the Component Selection -List/ Search window.



Select a Component Family from the like-named drop-down list box. A large number of component families are provided to speed the search. A brief description is given below:

Most Commonly Used: Approximately 100 components representing all of the pure components commonly encountered in natural gas and petroleum processing. Hydrocarbon Light ends: Light gases commonly reported on analysis for oil refinery streams. All Components: Every component in the SIMSCI and PROCESS databanks. Password Protected Libraries: Component properties taken from password protected libraries are shown with text “PROT” in GUI. Families of Specific Chemical Type: Twenty families in alphabetical order:

Acids

Additional Electrolyte Components

Alcohols

Aldehydes

Amides

Amines

Aromatic Hydrocarbons

Elements

Esters

Ethers

Halogenated Derivatives

Ketones

Miscellaneous

Naphthenic Hydrocarbons

Other Nitrogen Derivatives

Paraffinic Hydrocarbons

Salts and Minerals

Silicon Derivatives

Sulfur Derivatives

Unsaturated Hydrocarbons

For all families listed above, except for Hydrocarbon Light ends, you may define specific search criteria by selecting radio buttons and entering a search string. Use part or all of the component name, alias, or chemical formula as the search string. As components are located, transfer them to the Additions to Component List box. When you have located all the components, click OK to return to the

Chapter 8

Specifying Component, Thermodynamic, and Stream Data 97

Component Selection main window and to transfer the components to the List of Selected Components. The priority order for databanks may be defined by pushing the Databank Hierarchy button on the Component Selection main window to access the Component Selection – Databank Search Order window. This window initially displays the default search order and may be modified to search the databanks in any order. Components are always selected from the first databank in the search order in which they appear. Note: The newly added libraries and databank names in TDM can be recognized in this dialog box by Library Name: Databank Name.

Entering User-defined Components You may want to enter a component as a user-defined component when you wish to use a component that is not in the PRO/II library. 

Enter user-defined components by clicking User-defined… on the Component Selection main window to access the Component Definition User Defined window.



Type in the name of the user-defined component in the Component Name entry field.



Click OK to commit the new component name.

Note: At this point, you have only entered the name of the user-defined component in the database. Next, you must supply the properties for the component by the steps described below in Modifying Component Properties.

Defining Petroleum (PETRO) Components Define PETRO components by clicking Petroleum… on the Component Selection main window to access the Component Selection – Petroleum Components window. You may define any number of PETRO components in a single visit to this window by using the tabular input provided. You must supply at least two of the three correlating properties, normal boiling point, standard liquid density, and molecular weight for each component. Names may be optionally provided or will be supplied by PRO/II as NBP XXX where XXX is the component normal boiling point. PRO/II uses internal correlations to estimate the third parameter, when missing. All necessary physical and thermodynamic properties are computed from the three correlating properties. Molecular weight is the most difficult property to predict accurately from generalized correlations and should be supplied when possible, for the most accurate characterization for a PETRO component.


April 2014

Note: It is not possible to enter data for assay pseudo-components (which are based on stream assay information) with this window. All properties for components derived from assay data are automatically defined by PRO/II. The components are also added to the component list by PRO/II.

Defining Solid Components You can enter inputs for solid characteristics directly into PRO/II. You may specify stream properties, the particle size distribution, and the particle properties. PRO/II also allows you to input experimental solids solubility data. To add a solid component to the flowsheet: 

or select Input/Component Selection from the menu bar to Click open the Component Selection window.



Click Component Phases…. Ensure that the components that may be solid have the solid phase enabled. For example, if you enter NaCl for use in a dissolver, make sure that its component phase designation is “liquid-solid”.

In a flowsheet that includes unit operations that require particle size distributions (e.g., Cyclone, Dissolver, Crystallizer), choose Input/Component Property Data from the menu bar. In the like-named window, click Particle Size Distribution… to open the Particle Size Distribution for Solids window. Enter PSD cut points for all relevant solid components. Particle size grades are bounded by the cut points that are entered here. Grades will not be created on the open ends of the first and last cut points (i.e., if the cut points are 10 and 20 microns, there will be one grade of 10 to 20 microns, not three grades of less than 10, 10 to 20, and greater than 20 microns). To change the units of measure for the particle size distribution, click in any of the Distribution Ranges entry fields to enable the UOM button in the toolbar at the top of the window.

Deleting and Renaming Component Properties Currently, actions on components that appear in the List of Selected Components in the Component Selection main window are limited to deletion or renaming of components. To delete a component: 

Highlight the name of component in the List of Selected Components.



Click Delete.

To rename a component for printout purposes: 

Highlight the component.

Chapter 8




Click Rename… to open the Rename a Component window.



Enter the new name in the data entry field.

Modifying Component Properties You can modify properties for any component entered through the Component Selection main data entry window via the Component Property window. To reach this window: 

Select Input/Component Properties... from the menu bar or click the main toolbar.

on

The Component Properties window is the master navigation point for changing all component properties. Component properties taken from password protected libraries are shown with text “PROT” in GUI and users are not allowed to modify this data. Note: Component properties cannot be defined before the component names have been entered. There are three methods available for component property modification:

Method 1: Specifying Fixed Properties Click Fixed… to open the Components Properties-Fixed Properties window. Here, you can modify fixed component properties such as molecular weight, critical temperature and NBP. With the exception of assay components, all components can be modified via this window. For those properties having UOM's, all data is displayed with the UOM’s of the current problem. Starting from this window, use the appropriate button to modify other properties: 

Click Critical Properties… to specify critical temperature, critical pressure, critical volume and critical compressibility factor.



Click Molecular Constants… to specify properties such as Dipole Moment, Radius of Gyration, van der Waals Area parameter and van der Waals Volume parameter.



Click Heats of Formation… to specify Enthalpy of Formation and Gibbs Energy of Formation. In this entry, reference phase designation is a required input. The reference phase can be vapor, liquid or solid. Vapor phase is the default.



Click Miscellaneous Properties to specify Acentric Factor, Solubility Parameter, Rackett Parameter, Liquid Molar Volume, Heat of Vaporization, Heat of Fusion, Normal Melting Point, Triple Point Temperature, Triple Point Pressure, Heat of Combustion, Gross Heating


April 2014

Value, Lower Heating Value, Carbon Number and Hydrogen Deficiency Number. For PRO/II library components, the values in the database will appear in the various property windows. In cases where there is no library value to serve as the default, the default displayed will be the text “Missing.” You may reassign values for any of these properties.

Method 2: Specifying Temperature-dependent Properties You may enter or override default data for properties that change with temperature, such as density and viscosity, for the vapor, liquid or solid phases of the pure components in your simulation. You may supply new data in the form of tables or as correlation coefficients of one of 29 different equation types. Click Temperature Dependent to open the Component Properties –Temperature Dependent Properties window. All the library and user-defined components from the current problem are displayed. To enter or modify data for a property of a component, click on the corresponding push button for that component. For properties that may apply to more than one phase, you will first be required to select the phase for which you are to supply data in the Component Properties – Phase window, 

Click VP to enter or modify liquid or solid vapor pressure data



Click H to enter or modify vapor, liquid or solid enthalpy data



Click Cp to enter or modify solid heat capacity data



Click ∆Ην to enter or modify latent heat data



Click ρto enter or modify liquid or solid density data



Click µto enter or modify vapor or liquid viscosity data



Click κto enter or modify vapor, liquid or solid conductivity data



Click σ to enter or modify liquid surface tension data

In the Component Properties - Data Source Selection window, choose the method of data entry. You may enter data either in tabular form or as coefficients for one of as many as 29 equations. If you choose the Correlation Coefficients option, you may display the form of the equation by selecting the appropriate Correlation Number in the like-named dropdown list. 

Select one of the correlations and supply coefficients as required. If the form of the equation is logarithmic, you may select the base of the logarithm. You may change the units of the equation and may impose maximum and minimum temperatures of applicability.

Chapter 8


Note: The full range of equations can be found in the online PRO/II Reference Manual accessible via the Help system. If you choose an equation that is not standard, a message to that effect appears, and the border of the drop-down list box will be yellow. If you choose the Tabular Data option, the Component Properties –Tabular Data window appears. 

Enter temperature and property data. You must enter at least one data pair.

PRO/II and TDM Integration Physical and Thermodynamic data of a chemical component has a profound impact on the design and operation of a unit operation in a process industry. Users of PRO/II may utilize their own component data by using the Thermodynamic Data Manager (TDM program) to prepare the data; then use the LIBMGR program to store it in databases suitable for use by PRO/II. PRO/II in turn retrieves data from these libraries through library names and alias. 

LIBMGR – For managing user-defined pure component and binary libraries.



TDM (Thermodynamic Data Manager) – For reviewing and modifying pure component data



REGRESS (now available from both TDM and PRO/II)– For generating pure and binary interaction parameter data from experimental information.



Reporting – For publishing and archiving component and binary data

Current versions of PRO/II are integrated with the Thermodynamic Data Manager (TDM). This integration provides the following advantages to all PRO/II users. 

PRO/II can access data from the TDM-defined libraries as well as the default edlib.lb library provided by SIMSCI and installed with PRO/II.



Users can launch TDM GUI in different modes to define new libraries and databanks within libraries.



The Thermodynamic Data Manager incorporates REGRESS functionality, so all data preparation activities may be performed within the single TDM program.



Due to new library naming conventions, different versions of libraries now may co-exist in the same directory. This means, for example, a PRO/II version 7 library and a PRO/II version 8 library both may be used. It no longer is necessary to always replace older libraries with the newest version.


April 2014

Working with TDM provides these additional advantages: 

TDM allows users to build customized libraries containing pure component data as well as unary and binary thermodynamic parameters.



TDM can generate and display a variety of temperature-dependent graphical plots of tabulated data results.



Multiple databanks may be defined and available in a single library file.



TDM replaces DATAPREP (now obsolete) and includes REGRESS functionality.

New Keyword Format for Declaring Library Data Banks The integration of PRO/II with TDM facilitates the simultaneous use of several libraries, each containing multiple databanks. Consequently, a new keyword input syntax now requires entering both the library (file) name in addition to the individual data bank name. This has the form: LibraryId: DatabankId For example, the former declaration of : BANK=SIMSCI, PROCESS

Now may be fully declared as:

BANK= PROII_8.2:SIMSCI, PROII_8.2:PROCESS

Note: The ID of the library shipped with PRO/II changes with each major version. Refer to the PRO/II Installagion Notes for the current library identifiers. The colon ( : ) between LibraryId and DatabankId always is required. In the PROVISION Graphical User Interface, Library ID’s Component Selection and Thermodynamic Data - Databank Search Order dialog box, the newly added and existing libraries and databank names in TDM can be viewed. Users can select and add the libraries and data banks for the current simulation. Note: Refer to the Thermo Data Manager User Guide for detailed explanation on its functionalities.

Method 3: Specifying Fill From Structure The Fill from Structure button opens the Components Properties – Fill from Structure window. The Available Components list on the left side contains library and user-defined components from the current problem. You may add or remove components to be filled from structure to the like-named list on the right. Click ΟΚ to have the properties of the selected components filled from structure. PRO/II predicts properties from structure using established correlations and techniques. Joback (1985) significantly expanded the work of Lyderson (1955) in this area providing a group contribution method for the prediction of critical

Chapter 8


properties, boiling point, freezing point, ideal gas capacity, enthalpy, and Gibbs heat of formation. Joback used a4 large database of components to statistically determine group parameters for 42 different functional groups. SIMSCI has extended this work to include several missing parameters. To complete the Fill from Structure procedure, click UNIFAC Structures… on the Component Properties window to display the like-named window. A UNIFAC Structure entry is mandatory for all components for which Fill from Structure has been requested. Click UNIFAC Structures… adjacent to the component of interest to open the Define UNIFAC Structure window where you may choose from families of components or from the UNIFAC group number directly.

Assay Data General Information For many petroleum-based streams, the composition is not fully known in terms of defined components. These stocks must be characterized by pseudocomponents for which the necessary physical and thermodynamic properties have been estimated. PRO/II has extensive procedures for the translation of petroleum stream laboratory assay data into pseudo components. Pseudo-components are based on boiling point or “cut point” ranges on the true boiling point (TBP) distillation for the stock. The normal boiling point for a pseudo-component is defined as the weighted average temperature of its cut point range. The TBP distillation must often be derived from another type of laboratory distillation, using a conversion procedure. PRO/II accepts the following types of laboratory distillations: TBP, ASTM D1160, ASTM D86, and ASTM D2887. While laboratory distillations are usually reported on a 760 mm Hg basis, PRO/II has procedures to correct distillations for other laboratory pressures. Estimated values for the standard liquid gravity and molecular weight for each pseudo-component are also needed for the characterization process. The standard liquid gravity for each pseudo-component is derived from the gravity curve for the stream, in similar fashion to the normal boiling point. The gravity curve for the stream is often not available, and it must be estimated, based on the average stream gravity and the distillation curve. The molecular weight curve is seldom available, and the molecular weight for each pseudo-component is usually predicted from its normal boiling point and standard liquid gravity. All other required physical and thermodynamic properties may be estimated from the normal boiling point, standard liquid gravity, and molecular weight. The use of assay data in PRO/II is divided into two logical steps. The first step involves the definition of the cut point ranges and selection of the characterization options used in development of the pseudo components. Characterization options include distillation curve fitting and conversion methods, gravity curve generation procedure, methods for prediction of molecular weight,


April 2014

and methods for estimation of critical properties and ideal gas enthalpies. If the default cut point ranges and methods furnished by PRO/II are acceptable, this step may be omitted. The properties for all pseudo-components derived from the same cut point set are averaged, based on the stream flows, to develop a common set of blend components. This technique provides reasonable results when the streams have similar chemical natures. For example, all of the assay streams are products from the crude distillation unit. However, when assay streams are dissimilar chemically, such as virgin materials and cracked materials, there may be serious errors in the characterizations for the streams when a single set of blend components is used. For this reason, you are allowed to define additional cut point sets. For example, an additional cut point set may be defined to represent the products from an FCC reactor. Note that it is not necessary or desirable to define a separate cut point set for each assay stream. Similar streams may be grouped by using the same cut point set without a serious loss of accuracy. This also minimizes the number of components in the simulation, keeping calculation times smaller. The second step is supplying the petroleum stream laboratory assay data to PRO/II. This step is accomplished in the setup of initial feed streams and is discussed in the Stream Data section of this chapter.

TBP Cut point Sets TBP cut point sets are defined in the Assay Cut points and Characterization main data entry window. This window may be reached from the PFD main window in two ways: •

with the distillation pseudo-component curve on the toolbar, or Click select the menu bar item Input, then select the menu item Assay Characterization.

A Primary Cut point Set is always provided as a default by PRO/II. This set has the following cut point definitions: Cut point Range, Deg F

Cut point Range, Deg C

No of Cuts

100 - 800

38 - 427

28

800 - 1200

427 - 649

8

1200 - 1600

649 - 871

4

The default cut point ranges are usually reasonable for crude oil problems. They may be modified in the Assay Data Primary TBP Cut points Definition window which is accessed by clicking Modify... on the Assay Cut points and

Chapter 8


Characterization main data entry window. A convenient tabular form is provided for editing of the primary cut point set. Additional or Secondary cut point sets may be added to the problem by clicking Define New Cut point Set... on the Assay Cut points and Characterization main data entry window to access the Assay Data Secondary Set of TBP Cuts. A cut point set name is supplied on this window and a tabular entry form is provided for definition of the cut points. This window is also used to modify existing secondary cut point sets and is accessed by clicking Modify on the Assay Cut points and Characterization main data entry window and highlighting a secondary cut point set in the Defined Secondary Sets list box, on the Assay Cut points and Characterization main data entry window. Highlighted secondary cut point sets in the Assay Cut points and Characterization main data entry window may be deleted by clicking Delete.... This action removes the secondary cut point set from the problem. The Default Cut point Set is used for all streams for which a cut point set is not specified. Initially, it is defined as the Primary Cut point Set by PRO/II. After one or more Secondary cut point sets have been defined, the default cut point set may be changed via the drop-down list box on the Assay Cut points and Characterization main data entry window. It is convenient to define the cut point set which is used the most often as the default cut point set.

Assay Characterization Options Assay characterization options are selected on the Assay Characterization Options window which is reached by clicking Characterization Options on the Assay Cut points and Characterization main data entry window. Several groupings of options are shown in this window, with all options selectable with radio buttons. The option groups are as follows: Criticals, Ideal-Gas Enthalpy: SIMSCI (Twu) method (the default), Cavett method, or Lee-Kesler method, Cav80, Extended 1980 API and Heavy Oil. Molecular Weight: SIMSCI (Twu) method (the default), Old (1967) API method, or Extended 1980 API method, Lee-Kesler, Cav80 and Heavy Oil. Gravity Curve Generation Method: Constant Watson K from TBP Curve (default), or Constant Watson K from D86 Curve. Heat of Formation: Current or Version 9.1 Distillation Curve Inter-conversions: API 1987 (the default), API 1963, API 1994, or Edmister-Okamoto.


April 2014

Fitting Procedure: Cubic Spline, Quadratic Polynomials, or Probability Density Function (PDF), Alternate Cubic spline (default). Distillation Boundaries: Initial Point and End Point percentages. Include in PDF: Include Initial Boiling Point in fit, and/or include End Point in fit. Calculation of NBP for Cuts: Liquid Volume Average (default) or Temperature Midpoint. Curve Fit: Current or Version 8 or Version 6 The characterization options are explained in greater detail in the PRO/II help text and the online PRO/II Reference Manual accessed via the Help menu. Version 6 was the only available option until the Improved method was implemented for PRO/II version 7.0. This was renamed the Version 8 method and became the default in PRO/II 8.0. In PRO/II 8.1, yet another improvement was made and now is called the Current option. The Current option always will be the default, even if upgraded. In the future, when the Current option is upgraded, the older Current method will be renamed and be made available as a new option.

Thermodynamic Data General Information The selection of appropriate thermodynamic methods is an important and necessary step in the solution of flowsheet problems. PRO/II provides a wide range of methods to allow solution of the wide variety of systems which occur in the chemical process industries. Thermodynamic properties are an integral part of the flowsheet calculations. The equilibrium K-values (both VLE and LLE) are used to determine the phase separations. The enthalpies for the streams are used to determine the energy required to take a system of components from one set of thermal conditions to another. Entropies are used in the calculation of the isentropic operations and the Gibbs free energy minimization reactor. Liquid and vapor densities are used in heat transfer, pressure drop, and column tray sizing. Transport properties are selected in conjunction with the thermodynamic methods in PRO/II and are comprised of liquid and vapor viscosities, liquid and vapor thermal conductivities, and liquid diffusivities. While not strictly a transport property, liquid surface tension is also included. Transport properties find use in rigorous heat transfer calculations, pressure drop determination, and column sieve tray and packing calculations. Transport properties are also reported in the stream properties reports and may be requested in Heating/Cooling Curves reports.

Chapter 8


In PRO/II, the selection of thermodynamic methods has been simplified by the concept of the method set. Method sets consist of predefined thermodynamic methods for K-values (VLE and LLE), liquid and vapor enthalpies, entropies, vapor fugacities, and densities. Numerous predefined sets are provided. Multiple thermodynamic method sets may be selected for each flowsheet. For example, a default set may be specified for the overall flowsheet and other method sets used for individual units. A facility is also provided to modify the thermodynamic methods in the predefined method sets. Certain parameters for some of the thermodynamic methods may also be supplied.

Selecting Predefined Method Sets Selection of thermodynamic method sets is accomplished via the Thermodynamic Data window which may reached from the PFD main window in two ways: 

with the phase diagram on the toolbar or select the menu bar Click item Input/Thermodynamic Data.

For convenience, several Categories of method sets can be selected in the list box on the Thermodynamic Data window. The Primary Method, i.e., the method used for calculation of equilibrium K-values, for each method set in the selected Category appears in a drop-down list box and may be selected to add the method set to the Defined Systems for the problem. The Defined Systems appear in a list box and each may be selected for further action by highlighting the desired method and clicking Modify..., Delete..., Duplicate and Rename... on the Thermodynamic Data window. The method set for which action is to be taken is selected (highlighted) in the Defined Systems list box. Delete removes the selected method set from the problem. Duplicate creates a copy of the selected method set. This is useful when it is desired to copy the existing thermo system and make minor changes to it. The Rename option is used to change the name of the selected method set. This is useful when it is desired to use a method set more than one time in a problem, perhaps with different parameters. Modification of method sets is discussed later in this section. The following Categories of method sets are provided: Most Commonly Used: These method sets may be used for a wide variety of problems. Nearly all gas processing and oil refining calculations are handled satisfactorily. Method sets in this category are: Soave-Redlich- Kwong (SRK), Peng-Robinson (PR), Grayson-Streed (GS), Braun K-10 (BK10), Ideal, NRTL, UNIQUAC, and UNIFAC.


April 2014

Equations of State: Equations of state are applicable to wide ranges of temperatures and pressures. They can be used to calculate all thermodynamic properties, using the ideal gas state as the reference state. The cubic equations, in particular, are able to accurately predict critical and supercritical conditions. Equation of state method sets are: Soave-Redlich-Kwong (SRK), SRK-KabadiDanner (SRKKD), SRK-Huron-Vidal (SRKH), SRK-Panagiotopoulos-Reid (SRKP), SRK-Modified-Panagiotopoulos-Reid (SRKM), SRK-SIMSCI (SRKS), SRK-Hexamer (HEXAMER), Peng-Robinson (PR), PR-Huron-Vidal (PRH), PRPanagiotopoulos-Reid (PRP), PR-Modified-Panagiotopoulos-Reid (PRM), Predictive Peng-Robinson 78 (PPR78), BWRS (BWRS), Lee-Kesler-Plöcker (LKP), and Uniwaals (UNIWAALS). Liquid Activity: Liquid activity methods use liquid phase activity coefficient models to represent the liquid mixture in phase equilibrium calculations. This approach is useful for modeling strongly non-ideal liquid solution behavior. Methods available in PRO/II include: NRTL, UNIQUAC, Wilson, van Laar, Margules, Regular Solution, Flory-Huggins, UNIFAC, UNIFAC TDep-1, UNIFAC TDep-2, UNIFAC TDep-3, UNIFAC Free Volume, and Ideal. Generalized Correlations: Generalized correlations predict K-values with semirigorous equations. The Grayson-Streed and Chao-Seader correlations use the Redlich Kwong equation for vapor fugacities and empirical relationships for the liquid fugacities. Braun K-10 is based on the convergence pressure concept. A variety of other correlations are used to predict the other properties, i.e., enthalpies, entropies, and densities. Generalized correlations are: Braun-K10 (BK10), Grayson-Streed (GS), Improved-Grayson-Streed (IGS), Grayson-StreedErbar (GSE), Chao-Seader (CS), Chao-Seader-Erbar (CSE), and Ideal (IDEAL). Special Packages: Special packages are designed to solve a particular industrial application. Special packages in PRO/II are: Alcohol (ALCOHOL), Glycol (GLYCOL), Sour Water (SOUR), GPA Sour Water (GPSWATER), and Amine (AMINE) and CAPE-OPEN. All Primary Methods: This category includes all of the primary thermodynamic sets that are listed above. User-added Methods: This category includes all of the 15 user-added method sets that may be defined by the user. The PRO/II online help texts provide application guidelines for the various method sets, as well as a brief description for each method. More detailed information may also be found in the PRO/II Reference Manual (also available online). Table 8-1 at the end of this section gives a detailed list of the composite thermodynamic methods used for each predefined method set.

Chapter 8


Modifying Predefined Method Sets Predefined method sets are modified via the Thermodynamic Data-Modification window which is accessed by clicking Modify... in the Thermodynamic Data window. The pre-selected thermodynamic methods for the various thermodynamic properties may then be changed in this window by following the steps given below: 

Click on the Current Method drop-down list box corresponding to the Property type.



Select the replacement thermodynamic method.

Any or all of the thermodynamic methods may be changed for the method set being modified, including: K-value (VLE), K-value (LLE), liquid enthalpy, vapor enthalpy, liquid entropy, vapor entropy, liquid density, vapor density, and vapor fugacity (where applicable). Note: The newly added libraries and databank names in TDM can be recognized in this dialog box by Library Name: Databank Name. Some property-specific data may also be supplied and/or modified in this window for the thermodynamic methods by clicking Enter Data... in the Property-specific Data field. Many of the methods use specific parameters, such as binary interaction factors, modified acentric factors, etc. A priority search order may be defined for the selection of these parameters from more than one thermodynamic databank. Note that thermodynamic databanks are supplied by SIMSCI and may also be prepared by the user with the SIMSCI LIBMGR program. Property-specific data which apply only to the liquid activity methods include: fill options for missing parameters, Henry’s Law options, and Poynting correction options. For the liquid activity methods, a vapor fugacity method may also be selected. Other property-specific data which may be modified include the dimensionless residence time correction factor for amines DGA and MDEA and the key (or dominant) components in each liquid phase for K-value (LLE) methods. Key component selection is optional and PRO/II will determine them when not supplied. However, convergence time may be enhanced by pre-selecting the key components.

Fill-in Property Prediction PRO/II allows missing data to be “filled in” under several circumstances. For example, when the composition of an azeotrope and activity coefficient values at infinite dilution are known for some pair of species, you can use this option to predict missing activity coefficient values at intermediate concentrations.


April 2014

VLE and LLE K-value parameters for liquid activity coefficient methods may be estimated by the UNIFAC, Temperature-Dependent UNIFAC, Regular Solution, or Flory-Huggins methods, or they may be obtained from an azeotrope bank. The choice of fill-in property prediction is entered on the Binary Data Fill Options window, which is reached by clicking the corresponding Enter Data... button on the Thermodynamic Property Modification-Property Specific Data window. Checking the box will fill in missing data from the azeotrope databank. A method for filling in missing binary parameters (using the UNIFAC, modified UNIFAC, Regular Solution, or Flory-Huggins methods) may be selected by choosing the appropriate radio button.

Equation of State Alpha Data The form to be used for equation of state alphas may be specified on the Alpha Selection window. This window is reached by clicking the appropriate Enter Data... button on the Thermodynamic Property Modification-Property Specific Data window. The source of the alphas to be used in the equation of state may be designated by selecting the appropriate radio button.

Henry’s Law The Henry’s Law window is used to specify whether or not Henry’s Law is to be used in conjunction with a liquid-activity K-value method. This window is brought up by clicking Enter Data... on the Thermodynamic Property ModificationProperty Specific Data window. Checking the box on the Henry’s Law window causes Henry’s Law to be used to determine the solubility of certain components. Designation of solute components may either be determined by the program or selected explicitly by choosing the appropriate radio button. If the solute components are to be designated explicitly, the desired solute components must be selected from the list box on the Henry’s Law window.

Poynting Correction The Poynting Correction window is used to specify the use of the Poynting correction factor for liquid-phase fugacities. The Poynting Correction window is brought up by clicking the appropriate Enter Data... button on the Thermodynamic Property Modification-Property Specific Data window. There are three options to using the Poynting correction: 1. Default: This choice specifies that the Poynting correction will be used only if a vapor fugacity method is chosen. 2. Use Poynting Correction to Liquid Activities: Use the Poynting correction factor for the liquid phase fugacity. 3. Do Not Use Poynting Correction: Do not use Poynting correction factor.

Chapter 8


If either of the first two options is selected, then the liquid molar volume calculation method may be selected from the following choices: Standard (25°C) Volumes, Rackett, Rackett One-Fluid, or Library Density Correlations. The default method is Standard (25°C) Volumes. Note standard vapor conditions are different from standard conditions for liquid molar volume. See Table 1: Standard Conditions on page 47.

Amine Residence Time Correction Factor The Amine Residence Time Correction window is available only for the Amine special data package thermodynamic method for K-values. It is accessed by clicking Enter Data... on the Thermodynamic Property Modification-Property Specific Data window, then clicking LLE Key Components... on the LLE K-values window. A value for the residence time correction factor for systems containing amines MDEA or DGA may be entered in this window. The default value for this factor is 0.30.

LLE Key Components The LLE Key Components window can be accessed whenever an LLE K-Value method is selected, by clicking Enter Data... on the Thermodynamic Property Modification-Property Specific Data window, then clicking LLE Key Components... on the LLE K-value window. Both the light liquid phase and the heavy liquid phase can either be Determined During Calculations or Userspecified by selecting the appropriate radio buttons. When the User-Specified radio button is chosen, a component must be selected in the associated dropdown list box. This drop-down list contains all available liquid-phase components. One component may be selected for each key. Note: The newly added libraries and databank names in TDM can be recognized in this dialog box by Library Name: Databank Name.

Binary Interaction Parameters A number of methods in PRO/II allow the entry of binary interaction parameters. These include equations of state for many properties and liquid-activitycoefficient models for K-values. These parameters are entered on the Binary Interaction Parameters window, which is reached by clicking Enter Data... next to Binary Interaction Parameters on the Thermodynamic Property ModificationProperty Specific Data window. For each column of the grid, the two components for which the data is being entered must first be selected from the drop-down list boxes in the first two rows of the grid. Depending on the thermodynamic method set which has been selected, one or more parameters characterize the interaction between the two components. When the Binary Interaction Parameters window is initially brought up, the box at the top of the window must be checked in order to enable the grid where


April 2014

individual binary interaction parameters are entered. For the NRTL and UNIQUAC methods, there are several different forms of the binary interaction equations. For the NRTL method, the 5-Parameter equation is the default form. For the UNIQUAC method, the default is the 4-Parameter form of the equation. For these two methods, a different equation form may be selected for each component pair from the Equation Format drop-down list box, in order to enter the data in the most convenient form. Depending on the selection in the Equation Format list box, the appropriate rows in the grid become active. For most equation formats, many active parameters have default values of 0.0, except for the SRK-Modified Panagiotopoulos-Reid, PR-Modified Panagiotopoulos-Reid, Glycol, Sour, GPA Sour Water, and Amine methods, where the default value for parameters cij and cji is 1.0.

User supplied K-values A number of methods in PRO/II allow the user to overwrite the primary method Kvalues. The user supplied K-values are entered for all related components on the Thermo Properties - User supplied K-values dialog box. This dialog box is opened by clicking Enter Data... next to User supplied K-values on the Thermodynamic Property Modification-Property Specific Data window. The K-values are supplied through Thermodynamic Data - User supplied K-values dialog box by selecting either the correlated or tabular form. Correlation Coefficient: Antoine equation is used as a default correlation with 1 atm as reference pressure. The coefficients have default values of 0.0. Tabular Data: User needs to supply K-value for at least 2 temperature points for all the relevant components. Detailed information on default correlations is available in PRO/II Reference Manual. Selecting the “User Supplied” option for KVLE/KLLE in the Thermodynamic Property Modification window can also overwrite the entire KVLE/KLLE method.

Heat of Mixing Data For the ideal thermodynamic method, an excess enthalpy method may be specified on the Heat of Mixing window. This window is accessed by clicking Enter Data... beside liquid enthalpy on the Thermodynamic Property-Modification Data window, checking the check box and then clicking Enter Data on the Thermodynamic Property-Modification-Liquid Enthalpy window beside the Heat of Mixing data item. Checking the box on the Heat of Mixing window activates three radio buttons, and the excess enthalpy calculation method may be selected by choosing the desired radio button. If either of the Redlich-Kister Excess Enthalpy methods is chosen, then the Redlich-Kister binary parameters may be entered in the Binary Redlich-Kister Parameters window, which is accessed by

Chapter 8


clicking Enter Data.... When entering the Redlich-Kister binary parameters for any component pair, the Aij field is required and the other parameters have default values of 0.0.

User-added Thermodynamic Data To select a user-added thermodynamic method, select one of the fifteen useradded methods from the drop-down list box in the Primary Method field on the Thermodynamic Data window. The User-added Parameters window allows the input of parameters for user-added thermodynamic subroutines. For each row of the grid, the parameter number (from 1 to 2600) is entered in the first column and the parameter value is entered in the second column. Note: The User-added Subroutines supplement (an add-on to the standard PRO/II package) is required for user-added thermodynamic methods. Contact your local SIMSCI office for more information.

CAPE-OPEN Property Package The PRO/II CAPE-OPEN thermodynamics capability enables users to add third party CAPE-OPEN property packages to perform thermodynamic property calculations for streams on flowsheet. CAPE-OPEN standards are the uniform standards for interfacing process modeling software components developed specifically for the design and operation of chemical processes. These standards allow integration of different software components like Unit Operations and Thermodynamic Property Packages from different vendors into a single simulation.

Selecting the CAPE-OPEN Property Package To install a new CAPE-OPEN Property Package, execute the install program provided by the vendor. The install program should perform all actions necessary to copy the files to your computer and set up the required entries in the Windows Registry. After installation, you can launch PRO/II and immediately use the new CAPE-OPEN software components. When CAPE-OPEN is selected in the “Category" list box, a dialog displays a tree control filled with registered CAPEOPEN property packages and thermodynamic systems. User must select property package. To view the vendor information, components supported, properties supported and phase supported for the particular property package, select the CAPE-OPEN property package and click View. Property package thermo system can be selected for unit operations and streams.

Property Calculations When a Cape Open Property Package is selected for stream or unit operation calculations, the PRO/II Flash calls the CalcEquilibrium function in the property


April 2014

package. If CalcEquilibrium fails, PRO/II uses other properties, such as fugacity coefficients, from property package.

Defining Transport Properties Transport property methods are selected in the Thermodynamics –Transport Properties window which is accessed by clicking Transport Properties on the Thermodynamic System –Modification window. Transport properties, i.e., viscosities, thermal conductivities, liquid surface tension, and liquid diffusivities may be selected on a global basis via radio buttons as: specify individually, purecomponent averages, petroleum-based correlations, the TRAPP method, or user-added methods. Note that the TRAPP method does not predict liquid surface tension. The petroleum method is used to predict this property when TRAPP is selected. Drop-down list boxes may be used to replace any of the global methods, with these options for the properties: Vapor viscosities: None, pure-component average, petroleum correlation, TRAPP correlation, Bromley-Wilkey correlation, CAPE-OPEN, user-added, NIST,GERG04, AGA8. Liquid viscosities: None, pure-component average, petroleum correlation, TRAPP correlation, API correlation, SIMSCI correlation, kinematic viscosity, Lohrenz-Bray-Clark, Twu viscosity w/Twu Bull mixing rule, API viscosity w/Twu Bull mixing rule, Tight Woeflin (petro method), Medium Woeflin (petro method), Loose Woeflin (petro method), Tight Woeflin (pure method), Medium Woeflin (pure method), Loose Woeflin (pure method), CAPE-OPEN, user-added, NIST, GERG04. Vapor thermal conductivities: None, pure-component average, petroleum correlation, TRAPP correlation, CAPE-OPEN, user-added, NIST,GERG04, AGA8. Liquid thermal conductivities: None, pure-component average, petroleum correlations, TRAPP correlation, Latini correlation, API 96 Procedure 12A3.2, API 96 Procedure 12A4.1 (High Pressure), CAPE-OPEN, user-added, NIST,GERG04. Liquid surface tension: None, pure-component average, petroleum correlations, Parachor/Tacite, API 82 Procedure 10A3.2, CAPE-OPEN, useradded, NIST,GERG04. Note:

The None option for the methods above is available only when the Specify Individually option is selected for the Transport System.

Liquid diffusivity: None, Wilke-Chang. Note: A user-added method is not allowed for liquid diffusivity calculations.

Chapter 8


To select a user-added transport method, choose the User-added Subroutine option from the Transport Properties window and select one of the five methods from the drop-down list. Note: The User-added Subroutines Supplement (an add-on to the standard PRO/II package) is required for user-added transport methods. Contact your local SIMSCI office for more information. The PRO/II online help text provides additional information about the various transport property methods. More information may also be found in the PRO/II Reference Manual.

Specifying Water Decant Options When a method set which supports two-liquid phase calculations is selected via the Thermodynamic Data window, the Thermodynamics -Liquid- Liquid Options window appears. Radio buttons on this window may specify using a single liquid phase in the calculations (the default) or that two-liquid phase calculations are performed. For method sets that support water decant, the user may optionally select to decant water as a pure phase. The methods used for the decant water calculations are selected via radio buttons in the Water Options window which is reached by clicking Water Options... on the Thermodynamic System-Modification window. The following options are available: Calculation of Water Solubility in Non-aqueous Phase: SIMSCI Method (the default), SIMSCI Method (Extrapolating), Kerosene correlation, Compute from Equation of State (SRK and PR methods only). Additional options are available from the 1999 API Technical Data Book, Procedure 9A1.3. Options include LUBE, NAPH, APIKERO, PARA, GASO, JP3, and JP4. Calculation of Decanted Water Properties: Vapor-Liquid Saturation Values, Steam Tables and IAPWS-IF97 Steam Tables. Calculation of Water Partial Pressure: Sweet Gas GPSA Correlation, Sour Gas Wichert Correlation. More details on decant of free water are given in the online help text and in the PRO/II Reference Manual. Table 8-1a: Predefined Most Commonly Used Thermodynamic Method Sets Common: Vapor K-value Method Enthalpy SoaveRedlich-Kwong (SRK)

SRK


Liquid Enthalpy

Vapor Entropy

Liquid Entropy

Vapor Density

Liquid Density

Vapor Fugacity

SRK

SRK

SRK

SRK

API

NONE

April 2014

Table 8-1a: Predefined Most Commonly Used Thermodynamic Method Sets PengRobinson (PR)

PR

PR

PR

PR

PR

API

NONE

GraysonStreed (GS)

CP

CP

CP

CP

SRK

API

NONE

Braun-K10 (BK10)

JG

JG

CP

CP

IDEAL

API

NONE

NRTL (NRTL)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

UNIQUAC (UNIQUAC)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

UNIFAC (UNIFAC)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

Note: CP= Curl-Pitzer method, JG = Johnson-Grayson method, API= API Method Table 8-1b: Predefined Generalized Correlation Method Sets Generalized: Vapor Liquid K-value Method Enthalpy Enthalpy

Vapor Entropy

Liquid Entropy

Vapor Density

Liquid Density

Vapor Fugacity

Braun-K10 (BK10)

JG

JG

CP

CP

IDEAL

API

NONE

Chao-Seader (CS)

CP

CP

CP

CP

SRK

API

NONE

Chao-SeaderErbar (CSE)

CP

CP

CP

CP

SRK

API

NONE

Grayson-Streed (GS)

CP

CP

CP

CP

SRK

API

NONE

GraysonStreed-Erbar (GSE)

CP

CP

CP

CP

SRK

API

NONE

ImprovedGrayson-Streed (IGS)

CP

CP

CP

CP

SRK

API

NONE

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

NONE

Ideal (IDEAL)

Chapter 8


Table 8-1c: Predefined Equation of State Thermodynamic Method Sets Eqn of State: K-value Method

Liquid Enthalpy

Vapor Enthalpy

Vapor Entropy

Liquid Entropy

Vapor Density

Liquid Density

Vapor Fugacity

BWRS (BWRS)

BWRS

BWRS

BWRS

BWRS

BWRS

BWRS

NONE

Peng-Robinson (PR)

PR

PR

PR

PR

PR

API

NONE

PR-Huron-Vidal (PRH)

PRH

PRH

PRH

PRH

PRH

API

NONE

PRPanagiotopoulosReid (PRP)

PRP

PRP

PRP

PRP

PRP

API

NONE

PR-ModifiedPanag.-Reid (PRM)

PRM

PRM

PRM

PRM

PRM

API

NONE

Soave-RedlichKwong (SRK)

SRK

SRK

SRK

SRK

SRK

API

NONE

SRK-KabadiDanner (SRKKD)

SRKKD

SRKKD

SRKKD

SRKKD

SRKKD

API

NONE

SRK-Huron-Vidal (SRKH)

SRKH

SRKH

SRKH

SRKH

SRKH

API

NONE

SRKPanagiotopoulosReid (SRKP)

SRKP

SRKP

SRKP

SRKP

SRKP

API

NONE

SRK-ModifiedPanag.-Reid (SRKM)

SRKM

SRKM

SRKM

SRKM

SRKM

API

NONE

SRK-SIMSCI (SRKS)

SRKS

SRKS

SRKS

SRKS

SRKS

API

NONE

SRK-Hexamer (HEXA)

HEXA

HEXA

HEXA

HEXA

HEXA

API

NONE

LKP

LKP

LKP

LKP

LKP

API

NONE

Uniwaals (UNIW)

UNIW

UNIW

UNIW

UNIW

UNIW

UNIW

NONE

Predictive PengRobinson 78 (PPR78)

PR

PR

PR

PR

PR

API

NONE

Lee-KeslerPlöcker


April 2014

Table 8-1d: Predefined Liquid Activity Thermodynamic Method Sets Liq Activity: K-value Method

Liquid Vapor Entropy Entropy

Vapor Density

Liquid Density

Vapor Fugacity

NONE

IDEAL

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

NONE

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

Margules (MARGULES)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

Regular Solution (REGULAR)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

Flory-Huggins (FLORY)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

UNIFAC TDep-1 (UNIFAC TDep-1)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL


IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL


IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

UNIFAC Free Volume (UNIFAC Free Volume)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

IDEAL

Ideal (IDEAL)

IDEAL

IDEAL

NONE

NONE

IDEAL

IDEAL

NONE

Vapor Enthalpy

Liquid Enthalpy

NRTL (NRTL)

IDEAL

IDEAL

NONE

UNIQUAC (UNIQUAC)

IDEAL

IDEAL

UNIFAC (UNIFAC)

IDEAL

Wilson (WILSON) van Laar (VANLAAR)

Table 8-1e: Predefined Special Package Thermodynamic Method Sets Special:

Vapor Enthalpy

Liquid Enthalp y

Vapor Entropy

Liquid Entropy

Vapor Density

Liquid Density

Vapor Fugacit y

Alcohol (NRTL)

SRKM

IDEAL

SRKM

SRKM

SRKM

IDEAL

IDEAL

Amine (AMINE)

SRKM

AMINE

SRKM

SRKM

SRKM

IDEAL

NONE

K-value Method

Chapter 8


Glycol (GLYCOL)

SRKM

SRKM

SRKM

SRKM

SRKM

API

NONE

Sour Water (SOUR)

SRKM

IDEAL

SRKM

SRKM

SRKM

IDEAL

NONE

GPA Sour Water (GPSWAT)

SRKM

IDEAL

SRKM

SRKM

SRKM

IDEAL

NONE

Stream Data General Information This section of data is used to specify the thermal conditions and compositions for all feed streams in the flowsheet. It may also be used to furnish initial estimates of the composition and thermal conditions for recycle tear streams to enhance recycle convergence. Supplied data for tear streams or any other streams which are products from unit operations are used as estimates only and always replaced by the next calculated set of values. Finally, Reference streams may be defined to eliminate thermal recycles. Compositional streams may be of two types: composition fully defined in terms of defined components, or pseudo-components to be generated from petroleum assay data. Reference streams are always assigned the composition of the parent stream. Compositions may be defined on a mole, weight, standard liquid volume or vapor volume basis, corresponding to typical laboratory data. It is necessary to provide both a laboratory distillation and stream average gravity for petroleum assay streams. Light ends analyses, gravity curves, and molecular weight curves may optionally be furnished to improve the characterization of petroleum assay streams. The stream thermal conditions may be specified in a variety of ways including: defined temperature and pressure, bubble or dew point conditions, or fraction liquid. For reference streams, only the temperature and pressure may be defined.

Entering Stream Data You can enter data for a stream on the flowsheet. The data entry window that appears contains any data you previously entered (as well as default values) for the selected stream.


April 2014

To enter data for a stream: 

Double-click on the stream or right-click on the unit icon and select Enter Data... or select the stream and choose Input/Data Entry... from the menu bar.



Select the desired stream operation.

The stream name automatically assigned by the program is displayed in the upper left hand corner of this window and may be edited as desired. If the stream is an intermediate or product stream, a check box appears on this window so that an initial estimate may be supplied for the stream. 

Select the Stream Type.

Figure 8-1: Stream Data Entry Window - Feed Stream

Specifying Composition Defined Streams Within the Stream Data main data entry window: 

Select the Composition Defined radio button.



Click Flow rate and Composition to access the Flow rate and Composition window.

Chapter 8


Radio buttons are used to select the stream flow rate basis as: Total Fluid Rate, or Individual Component Flow rates. A data entry box adjacent to the Total Fluid Rate button is used to enter the total stream flow in mole, mass, standard liquid volume, or standard vapor volume units. The stream composition is supplied in a drop-down list box, and may be supplied on a mole, mass, standard liquid volume, or standard vapor basis. Components not defined are assigned zero flow rates. If the total fluid rate was not given, the flow rate for the stream is taken as the sum of the stream composition. PRO/II displays a running total for the composition as it is entered.

When the total fluid rate is supplied and the composition does not sum to that percentage or 1.00 ± 0.01 (indica ting 1.0 rate or a rate of 100.00 ± or fraction) an error is signaled. Optionally, a check box is provided to normalize the composition based on the specified total fluid rate, in which case no error is signaled for the above condition.

Specifying Stream Thermal Condition The thermal condition for all supplied streams except reference streams must be specified on the Stream Data main data entry window. Two specifications must be supplied. The first specification is selected as Temperature or Pressure via the First Specification drop-down list box and the value entered in an adjacent data entry field. The second is chosen from the Second Specification drop-down list box as: Pressure, Bubble Point, Dew Point, Liquid Mole Fraction, Liquid Weight Fraction, or Liquid Volume Fraction. The pressure and the liquid fraction specifications have an adjacent data entry field. Thus, the thermal condition may be: 

Defined temperature and pressure.



Bubble or dew point (pressure defined, temperature calculated).



Bubble or dew point (temperature defined, pressure calculated).



Liquid fraction (pressure defined, temperature calculated).



Liquid fraction (temperature defined, pressure calculated).

The temperature and pressure may optionally be specified for a reference stream. If not specified, the thermal conditions for the parent stream are used.

Specifying Petroleum Assay Streams Within the Stream Data main data entry window: 

Select the Petroleum Assay radio button.



Click Flow rate and Assay to enter the Flow rate and Assay window.


April 2014

The flow rate for the assay stream is entered in the data entry field provided as weight or liquid volume units. The cut point set for the blend may be selected by clicking the hypertext string default set of TBP cut points to retrieve a list of the problem cut point sets. The pseudo-component blending option is selected by clicking the text string included in. This option is the default and includes the pseudo-components generated for the stream in the assay blending for the cut point set. The excluded from option is used when the assay stream is a recycle estimate and the effect of its estimated pseudo-components on the assay blend properties is not wanted. Entry of the various assay data is discussed below. More information on the various laboratory tests is given in the PRO/II help text and the PRO/II Reference Manual.

Laboratory Distillation 

Click Define/Edit Assay... on the Petroleum Assay Stream window to enter the Assay Definition window. This window is used to enter the laboratory assay data for the petroleum stream.



Select the type of distillation via radio buttons as: True Boiling Point (TBP), ASTM D86, ASTM D1160, or ASTM D2887.

The basis for the distillation may be chosen as: Liquid Volume or Weight. Liquid Volume is the default for all distillations except the ASTM D2887 which is defaulted as weight. Note that gravity and molecular weight curves must be on the same basis, volume or weight, as the distillation curve. The distillation data for TBP, ASTM D86, and ASTM D1160 are assumed to be at a pressure basis of 14.696 psia. If not, enter the laboratory pressure in the data field provided. For ASTM D86 distillations, a Correct for Cracking check box is provided for application of the API Data Book cracking correction to the distillation temperatures. The distillation data are entered in the table provided. At least two points are required when the cubic spline fitting method is used. When only two points are given, PRO/II uses a probability density function to fill in the curve. For the quadratic fitting option, at least three points must be given for TBP’s and five points for other types of distillations. PRO/II needs the entire distillation curve from zero percent to one hundred percent and extrapolates and interpolates as necessary. Wise engineers perform their own extrapolations outside of PRO/II, using their knowledge of the stream being characterized.

Gravity Data The type of gravity data is denoted by radio buttons on the Assay Definition window as: API Gravity, Specific Gravity, or Watson K-Factor. The stream average value must be supplied in the data entry window provided. Optionally, a gravity curve for the stream may be given by clicking Gravity Curve... on this

Chapter 8


window to access the Assay Gravity Curve window which provides a convenient tabular form for entry of the gravity curve.

Molecular Weight Data A molecular weight curve may be optionally given by clicking Molecular Weight... on the Assay Definition window to access the Assay Molecular Weight Data window. This window provides a tabular form for entry of the molecular weight curve. Optionally, the stream average value may also be supplied in this window.

Light ends Data Light ends data may be optionally provided by clicking Light ends... on the Assay Definition window to access the Assay Light ends Data window. The light ends composition may be entered on a mole, mass, standard liquid volume, or standard vapor volume basis. See Table 1: Standard Conditions on page 47 for differences in standard conditions. Any library component or petroleum component that was defined as a PETRO component may be designated as a light end. Several choices are available for specification of the total light ends flow. These choices are selected via radio buttons and are: Match to TBP Curve: The light ends rate is determined such that the normal boiling point for the mid percent of the highest boiling light end exactly matches the TBP curve. The light end components are kept in the same proportions as the supplied composition (the default). Fraction of Assay: The light ends rate is a specified fraction of the total stream rate. A basis of liquid volume or weight may also be selected in the Basis drop-down list box. If no basis is selected, the basis for the distillation curve is assumed. When this option is chosen and the light ends composition does not add to the specified fraction or to 100.0 ± 1.0 or 1.00 ± 0.01 (indicating composition percentage or composition fraction) an error is signaled. Percent of Assay: The light ends rate is a specified percent of the total stream

rate. A basis of liquid volume or weight may also be selected in the Basis drop-down list box. If no basis is selected, the basis for the distillation curve is assumed. When this option is chosen and the light ends composition does not add to the specified percent or to 100.0 ± 1.0 or 1.00 ± 0.01 (indicating composition percentage or composition fraction) an error is signaled. Use Compositions as Actual Rates: The supplied composition is assumed to be component flows, not fractional composition or percentage composition.


April 2014

Light ends Rate: The light ends rate is supplied directly in the data entry field

provided. When this option is chosen and the light ends composition does not add to 100.0 ± 1.0 or 1.00 ± 0.01 (indicating composition percentage or composition fraction) an error is signaled. Optionally, a check box is provided to normalize the composition based on the specified total light ends rate, in which case no error is signaled for a composition total which does not equal fraction, percent or a supplied rate and does not add to 100.0 ± 1.0 or 1.00 ± 0.01.

Assay Stream Thermal Conditions The thermal conditions for petroleum assay streams are specified in the same fashion as that already discussed for compositionally defined streams.

Specifying Recycle Streams The PRO/II calculation engine recognizes recycle loops and automatically sets up loop calculations as needed. For many problems, the default techniques are satisfactory. For complicated flowsheets with nested recycle loops, the user may prefer to define the loop calculation details. Acceleration techniques can also be applied to speed closure of the recycle tear streams.

Setting Recycle Convergence Options Recycle convergence options are entered in the Problem Recycle Convergence and Acceleration Options window which may be reached from the PFD main on the toolbar. The following Recycle Convergence window by clicking Options can be selected with radio buttons: Converge all Streams: Convergence is not attained until all flowsheet streams are converged within the recycle tolerances. This is the default. Converge only Tear Streams: Convergence is reached when all tear streams are converged. This is the option used by the SIMSCI PROCESS Simulation Program. Global recycle tolerances may be set in this window. These tolerances are used for all loops except user specified loops in which tolerances are supplied. Tolerances may be specified as relative or absolute via drop-down list boxes. Tolerances are: Component: The allowed change in a stream component rate from one iteration to the next. The default is 0.01 on a relative basis. Temperature: Allowed change in a stream temperature from one iteration to another. The default is ±1.0°F or equivalent.

Chapter 8


Pressure: Allowed change in stream pressure between iterations. The default is 0.01 on a relative basis. The smallest stream component mole fraction to test for convergence may be changed from the default value of 0.01 by clicking on the linked text numeric value. Note that for some problems such as amine plants, this threshold must be lowered to test the residual acid gas components in the recycle amine solution. Set the frequency of intermediate results printed for recycle calculations by clicking the underlined value in the print statement: Print recycle stream composition every 0 recycle iterations. The number of recycle trials to allow before non-convergence is signaled may be entered by clicking the underlined value in the trials statement: Set default maximum number of trials for each recycle loop to 20. Note that this is a global value which may be superseded for a user specified loop.

Acceleration options are chosen via radio buttons: Direct Substitution (No Acceleration): This is the default. Apply Wegstein Acceleration: Use the Wegstein acceleration method. The following additional options may be chosen with Wegstein by clicking underlined default values: first iteration to accelerate (default is 2), iteration interval for acceleration (default is 1), Wegstein lower and upper factors (defaults are -5.00 and 0.00) Apply Broyden Acceleration: Use the Broyden acceleration method. When this option is selected, the first iteration to accelerate may also be supplied by clicking the underlined (linked text) default value of 2. Ordinarily, all recycle tear streams are accelerated. Click Accelerated Tear Streams... to access the Accelerated Tear Streams window. This window has two options available: Accelerate All Tear Streams: This is the default. Accelerate User-specified Tear Streams: When this option is selected, tear streams are selected in a drop-down list box and moved to the Accelerated Streams list box. Acceleration is only applied to these tear streams in the Accelerated Streams list box.

User-specified Recycle Loops To select user-specified recycle loops, the user must first select the Alternate or Explicitly Defined by User calculation sequence methods in the Problem Calculation Sequence window.


April 2014



Click User-specified Recycle Loops on the Problem Recycle Convergence and Acceleration Options window to reach the Userspecified Recycle Loops window.



Then, click the check box beside User-specified Recycle Loops.

A tabular form is used to supply recycle loop information. Each line in the table has drop-down list boxes which are used to select the Starting Unit and the Ending Unit for each loop. The adjacent Enter Data... button is clicked to enter additional recycle information via the Individual Recycle Loop Data window. Information which may be entered in this window includes: Number of Trials: Number of iteration trials before non-convergence is signaled. If not supplied, the global value is used. Recycle Stream Convergence Tolerances: Tolerances may be supplied for the Component, Temperature, and Pressure changes. A threshold component level may be supplied by clicking the underlined (linked text) default. Note that the global defaults are used when values are not supplied in this window. Acceleration Options: The Direct Substitution, Wegstein Acceleration, or Broyden Acceleration methods may be selected for acceleration of the tear stream. The following additional options may be chosen with Wegstein by clicking highlighted default values: first iteration to accelerate (default is 2), iteration interval for acceleration (default is 1), Wegstein lower and upper factors (defaults are -5.00 and 0.00). For Broyden, the first iteration to accelerate may also be supplied by clicking the highlighted default value of 2.

Scaling Product Streams Scaling provides an easy way to ratio all of the results in a simulation such that the flow of one of the products is equal to a specified flow. For example, it may be desired to build a plant which produces a specified quantity of product, but the exact quantity of feed required is not known. Instead of making multiple runs with different feed rates, one run may be made and the complete result scaled, including the feed rate such that the desired product rate is achieved. To use the scaling feature: 

Select Report Format from the Output menu.



Select Miscellaneous Data from the Report Format menu to access the Miscellaneous Report Options window.



Click Product Stream Scaling to display the Product Stream Scaling window.



Click the check box beside Scale Stream Flow rate.

Chapter 8




Next, pick the stream to scale from the Stream Name drop-down list box in the Product Stream Scaling window and select the stream components on which the scaling rate is based, with the radio button provided. The default is All Components. If the Range of Components is selected, the starting and ending components are chosen in drop-down list boxes and the scaling rate is applied to the total of all components in this range.

The rate for the scaled product stream, either the total stream or a specified range of components, is supplied in the data entry field provided. The Units of may be used to supply the scaling rate as moles, mass, Measure feature standard liquid volume units, or standard vapor volume units.

Non-scaleable Unit Operations Some unit operation results are not scaleable, that is, the calculated results are dependent on the absolute flow through the unit. For example, the calculated pressure drop through a pipe of specified diameter depends on the flow through the pipe and may not be directly scaled for other flow rates. PRO/II disables the scaling option when unit operations are present which are non-scalable. The following unit operations are non-scalable: Column Hydraulics, Rigorous Heat Transfer, Pipe, Depressuring, Plug Flow Reactor.

Specifying Reference Streams A reference stream is a stream of identical composition to its parent stream. Changes in the composition of the parent stream immediately update the composition of the reference stream to match the new values in the parent stream. This concept is very useful in eliminating thermal recycles in flowsheets. Reference streams are designated by double-clicking the stream on the PFD to retrieve the Stream Data main data entry window, selecting the radio button Referenced to Stream, and choosing the parent stream in the drop-down list box. Optionally, a rate may be supplied for the reference stream. If not supplied, the rate of the parent stream is assumed. Optionally, a temperature and pressure may be specified for the reference stream. If not specified, the thermal conditions of the parent stream are used.

Copying Stream Data PRO/II allows you to copy the thermal and composition data for one or more selected streams. Process data for a selected stream can be copied to a new flowsheet stream or can be used to replace the currently existing data in another selected stream.


April 2014

In the case of multiple source streams, the target streams are new flowsheet streams only. Note: Copying of multiple streams on to existing streams is not supported.

Creating a New Stream from an Existing Stream In the PRO/II main window: 

Select the desired single stream or multiple streams to copy by clicking the stream label with the mouse.



Multiple streams can be selected using Shift key. When you select multiple streams, a selection box is drawn and only the streams that are explicitly selected will be part of Copy/Paste operation. Note: Selection with Ctrl keys not available.



Choose Copy on the Edit menu.



Click the left mouse button on an unoccupied area of the PFD main window or choose Select None on the Edit Menu to deselect the selected stream.

The data for the selected stream can now be copied to a new stream as follows: 

Choose Paste on the Edit Menu.



Create a new stream by clicking the left mouse button on an unoccupied area of the PFD main window or on one of the available exit ports for a unit icon.



Drag the mouse to the desired unoccupied area of the PFD or feed port of another unit.



Release the mouse button to complete the creation of the stream.

Create additional duplicate streams if desired, or 

Click the right mouse button or press to exit stream mode.

The newly created stream(s) will have the same thermal conditions, composition, and description as the original source stream.

Copying Data from a Stream to another Stream In the PFD main window: 

Select the desired stream to copy by clicking on the stream label with the left mouse button.




Chapter 8




Click the left mouse button on an unoccupied area of the PFD main window or choose Select None on the Edit menu to deselect the selected stream.

The data for the selected stream can now be copied to one or more existing streams as follows: 

Select the desired destination stream(s) with the left mouse button.



Choose Paste on the Edit menu.

The data from the original source stream will be copied to the destination stream(s), overriding any existing. For compositionally-defined streams containing calculated data, PRO/II allows the user to copy the calculated data (temperature, pressure, and one of total composition, liquid composition, or vapor composition) into the designated stream(s). 

Select the desired compositionally-defined stream to copy by clicking on the stream.






Select the desired destination stream(s) with the left mouse button.



Choose Paste Special from the Edit menu.

You may choose to paste only the input data of the selected stream or paste the input data and calculated data (using the total composition, or vapor composition, or liquid composition). Note: •

Copy/Paste of an assay stream on to the product stream changes the blend option to XBLEND. This is because the product streams are not involved in the calculation of new stream properties.

•

The Paste Special option is not allowed if new pseudo-components generate i.e., flowsheet resets. Again, Paste Special can be enabled by generating the calculated data.

•

Pasting a calculated data of an assay stream using Paste Special (total composition, liquid composition, or vapor composition) on the targeted stream will erase their assay composition data if a new pseudo-component is generated anywhere in the flowsheet.

•

The Paste Special option is not allowed when multiple streams are selected for copy.

Copying Input Stream Data Across Simulation Databases The Stream Data Link feature described previously will only transfer calculated data from the source stream to the input data slots of the destination stream. To


April 2014

copy input stream data from one simulation database to another, you must use the Windows Clipboard. To transfer input stream data from one database to another: 

Select File/Open menu to open the first database.



Highlight the stream of interest and copy the input data of this stream to the Windows clipboard by using the Edit/Copy menu.



Open up the second database using the File/Open menu.



Paste the clipboard data into the destination stream using the Edit/Paste Special menu.

Linking Stream Data Across Simulation Databases The Stream Data Link feature allows for the transfer of calculated stream data across PRO/II simulation databases. By using this feature, you can copy calculated stream data from a source database to the input data of a destination database. When modeling a large flowsheet, this practical feature enables you to: 

Quickly make use of stream data previously calculated in an upstream section of the plant



Avoid possible simulation errors due to manual re-entry of stream data



Easily model each section of the flowsheet as a separate simulation, with each section connected by a stream data link.

To define a Stream Data Link: 

Highlight the stream to be linked to a previous database by clicking on it.



Select the Define Stream Data Link option from the Input menu.

This brings up the Define Stream Data Link window as shown in Figure 7-15. In this window you must select both the name of the previously-run database file, and the stream from that simulation to be linked to your current simulation. 

Click on the Define Link check box.



Enter the name of the previously-run database file, or click on the Browse button to select from a list of available database files.



Enter the name of the stream from the previously-run database to be linked to the stream in your current simulation, or click on the Browse button to select from a list of available streams.



Click

Chapter 8

to return to the main PFD.


Note: You can link a stream in the current flowsheet to another stream in the same flowsheet. This includes linking the input of the currently selected stream to the calculated output data for that stream.

Updating Stream Data Links You may update a stream data link while defining that link or you may update all defined links at a later time via the Input menu. To update a Stream Data Link while defining that link: 

Check the Update Now check box in the Define Stream Data Link window.



Click Modify.

To update all defined Stream Data Links: 

Select Update Stream Data Links menu option from the Input menu.

Note: If the components are different in the two simulation databases, some component rate information may be discarded during the data transfer. If the source stream has rate information for a component which is not present in the second database, that rate information will be ignored. If the source stream contains assay pseudo-components, no component data will be copied to the target stream unless an identical assay exists in the current (target) simulation. Note: All stream data link information will be lost if you export the simulation data to a PRO/II keyword file and then re-import the keyword file.

Refinery Inspection and User-defined Properties Refinery Inspection Properties and User-defined Special Properties are available in PRO/II for calculating bulk stream properties. The stream values of the properties can be included in the PRO/II output and can be used in performance specifications. Refinery Inspection Properties comprises fifty-three predefined properties, commonly used by refineries for measuring and specifying unit operation performance. Examples are cetane index, sulfur content, pour point, and kinematic viscosity. User-defined Special Properties can be defined for any other property for which component data or assay data can be provided. Possible examples include auto-ignition temperature, color, $/tonne.


April 2014

Using Refinery Inspection Properties and User-defined Special Properties in a Flowsheet Refinery Inspection Properties and User-defined Special Properties are used in the following ways:

Globally Through the Component Properties Window Global property data for each component in the flowsheet are entered through the Component Properties window. Values entered here are used everywhere in the flowsheet unless overridden through the Thermodynamic Data window, as described below.

Through the Stream Data Window For streams that are to be defined in terms of assay curves, stream values of Refinery Inspection Properties and User-defined Special Properties can be entered either as curves or as average values or both.

Through the Thermodynamic Data Window The properties that are to be used are specified in the Thermodynamic Data window. If there is more than one thermodynamic system in the flowsheet, some properties may be specified for use in one system and others in another. Component data for each specified property can also be entered for each thermodynamic system. Any component data entered for a thermodynamic system will be used in preference to the data provided globally wherever that thermodynamic system is invoked. Note: A property is available only if it has been specified for a thermodynamic system through the Thermodynamic Data window and is available only in those unit operations where that thermodynamic system is used.

Entering Global Data Through the Component Properties Window Global component data are entered for each component through the Component Properties window of PRO/II. Values entered here are used everywhere in the flowsheet unless overridden through the Thermodynamic Data window.

Entering Refinery Inspection Properties To enter component refinery inspection property data globally: 

Click on the toolbar or select Input/Component Properties.... The Component Properties window appears.

Chapter 8




Click Refinery Inspection Properties to bring up the Component Property Selection for Refinery Inspection Properties window.



Select a property from the Property Name drop-down list box.



Click Enter Data... to enter global values. If the property is Kinematic Viscosity, the Component Data Entry for Kinematic Viscosity window will open. Otherwise the Component Data Entry for Refinery Inspection and User-defined Special Properties window will open.



For each component enter either a Data value or an Index value. For some properties the index method is not applicable and no index values may be entered. If the property is Kinematic Viscosity, enter values at two temperatures.

The stream property value is calculated from the individual component values using a chosen stream mixing method. Note: The SIMSCI databank contains Refinery Inspection Properties for some components; these data will be used if no value is entered in the input. If no data are present for a component, a fill method can be chosen through the Thermodynamic Data window (see below).

User-defined Special Properties To enter component user-defined special property data globally: 

Click on the toolbar or select Input/Component Properties... from the menu bar. The Component Properties window appears.



Click User-defined Special Properties to access the Component Property Selection for User-defined Special Properties window.



Enter the name of a new Special Property in the Property Name dropdown list box or select a special property from the list.



Click Enter Data... to enter global values. The Component Data Entry for Refinery Inspection and User-defined Special Properties window will open.



For each component, enter either a Data value or an Index value.

Entering Assay Data for Stream Special Properties For streams that are defined in terms of assay curves, stream values of Refinery Inspection Properties and User-defined Special Properties can be entered either as curves or as average values.


April 2014

Assay Data for Refinery Inspection Properties To enter assay data for refinery inspection properties: 

Double-click on the stream on the PFD. The Stream Data window appears.



In the Stream Data window, click the Petroleum Assay radio button and then click Flow rate and Assay to access the Flow rate and Assay window.



In the Flow rate and Assay window, click Define/Edit Assay... to access the Stream Data - Assay Definition window.



In the Stream Data - Assay Definition window, first click the appropriate distillation method radio button and then click Refinery Inspection Properties to access the Assay Property Selection for Refinery Inspection Properties window.



Select a property from the Property Name drop-down list box.



Click Enter Data... to enter global values. If the Property is Kinematic Viscosity, the Assay Data Entry for Kinematic Viscosity window will open. Otherwise the Assay Data Entry for Refinery Inspection and Userdefined Special Properties window will open.



Enter the property value(s) as a stream average, a curve against Percent Distilled, or both. If the property is Kinematic Viscosity, enter values at two temperatures.

Assay Data for User-defined Special Properties To enter assay data for user-defined special properties: 

Double-click on the stream on the PFD. The Stream Data window appears.



In the Stream Data window click Flow rate and Assay to access the Flow rate and Assay window.



In the Flow rate and Assay window click Define/Edit Assay... to access the Stream Data - Assay Definition window.



In the Stream Data - Assay Definition window click User-defined Special Properties to access the Assay Property Selection for User-defined Special Properties.



Enter the name of a new Special Property in the Property Name dropdown list box or select a special property from the list.

Chapter 8




Click Enter Data... to enter global values. The Assay Data Entry for Refinery Inspection and User-defined Special Properties window will open.



Enter the property value(s) as a stream average, a curve against Percent Distilled, or both.

Assigning Refinery Inspection Properties and Userdefined Special Properties to Thermodynamic Systems The properties that are to be used in the simulation must be specified through the Thermodynamic Data window. If there is more than one thermodynamic system in the flowsheet, some properties may be specified for use in one system and others in another. A property is available only if it has been specified for a thermodynamic system and only in those unit operations where that thermodynamic system is used. Component data for each specified property can also be entered for each thermodynamic system. Any component data entered in a thermodynamic system will be used in preference to the component Global data wherever that thermodynamic system is invoked. To assign refinery inspection properties to a Thermodynamic System: 

Click or select Thermodynamic Data... on the Input menu bar item. The Thermodynamic Data window appears.



Select the system for which modifications are to be made in the Defined Systems box.



Click Modify... to access the Thermodynamic Data –Modification Window.



Click Refinery Inspection Properties. The Thermodynamic Method Selection for Refinery Inspection Properties window appears. This window has a table in which properties and associated parameters and data will be entered. To eliminate the need to enter standard sets of properties repeatedly, predefined lists of properties have been set up.



To load the table with a predefined list of properties, select from the Predefined Lists list. Selecting None in this list removes all properties from the table.



Select a property from the Property Name drop-down list box in the table.

This displays the available options, and default selections, for the selected property. Change these as required. The options are:


April 2014

Stream Method, which defines the method used to mix component property values to produce a value for the stream. The available options are: i. Summation: The stream property value is determined by summing the product of the component property value and the component fraction. The fraction may be molar, weight or liquid volume and is calculated from the total stream dry composition except for kinematic viscosity when it is from the dry liquid part of the stream. Any Index data supplied for the property will be converted to property values before the summation, using the equation: Index     Reference Index 

³

Value = Reference Value × 

ii. Index: The stream property index is determined by summing the product of the component property index and the component fraction. The fraction may be molar, weight or liquid volume and is calculated from the total stream dry composition except for kinematic viscosity when it is from the dry liquid part of the stream. Before the summation, any supplied property values will be converted to index values using the equation: Value   Index = Reference Index ×    Reference Value 

γ

This equation is then used to convert the stream index value to the stream property value. iii. User-Formula: The stream property value is determined from the equation in a user-added subroutine, which is linked into PRO/II. Data values may be entered for each component and up to 20 real and integer data values may also be supplied. iv. User-Index: The stream property value is determined by a user-added subroutine, which is linked into PRO/II. The same data as for the Index method is available to the user-added subroutine. v. SIMSCI: This method is only available for cloud point and kinematic viscosity. It is an index method but uses specific index equations. vi. API: API procedures may be used to calculate flash point, cetane index, mean average boiling point, cubic average boiling point, moleaverage boiling point, weight-average boiling point, volume-average boiling point, or heat of combustion. The API method requires no component data.

Chapter 8


vii. Nelson: This is an alternative correlation to calculate flash point and no component data are required. viii. Stream Basis, which specifies whether the component values will be mixed using their mole, weight or liquid volume fractions. ix. Component Fill, which specifies the action to be taken when component values are missing for petroleum fractions in the stream. The available options are: a. Zero: This option sets the property value to 0.0. b. No fill: This produces warning messages for missing data and set to 0.0. c.

SIMSCI: This option estimates missing data by SIMSCI correlations for kinematic viscosity, smoke point, hydrogen content, carbon content or carbon-hydrogen ratio.

d. API: This estimates missing data by API methods for kinematic viscosity, pour point or refractive index. e. Nelson: This option estimates missing data by Nelson method for smoke point. x. Component Blend, which defines the way in which missing data are handled when calculating properties from blended assay streams. The options are: a. Zero: The property value for the cuts in the assay with no data is set to 0.0. b. Exclude: The property is calculated by blending only those assays, which have data for this property. c. Missing: For this option, the blended property is not calculated and is reported as “Missing”. 

Click Data… to enter data for this property, for this thermodynamic system. If the Stream Method is defined as User-Formula, the User Formula Data Entry window opens. Otherwise, if the property is Kinematic Viscosity, the Kinematic Viscosity Data Entry window will open and for other properties, the Refinery Inspection and User-defined Special Properties Data Entry window will open.



In the Kinematic Viscosity Data Entry window or the Refinery Inspection and User-defined Special Properties Data Entry window, for each component, enter either a Data value or an Index value. For each component, enter either a Data value or an Index value. If an Index value is entered, Reference Index Data must also be entered. For some properties, the Index method is not applicable and neither Index values


April 2014

nor Reference Index Data may be entered. If the property is Kinematic Viscosity, enter values at two temperatures. 

In the User Formula Data Entry window, for each component, enter a Data value, which will be passed to a linked User-added Subroutine. Up to twenty real and integer values an also be passed to the subroutine. The meaning of the data is determined by the calculation subroutine.

User-defined Special Properties To assign user-defined special properties to a Thermodynamic System: 

Click or select Thermodynamic Data... on the Input menu bar item. The Thermodynamic Data window appears.



Select the system for which modifications are to be made in the Defined Systems list box.



Click Modify... to access the Thermodynamic Data Modification Window.



Click User-defined Properties. The Thermodynamic Method Selection for User defined Properties window appears. This window has a table in which properties, associated parameters and data will be entered.



Enter the name of a new special property in the Property Name dropdown list box or select a special property from the list. Change the available options and their default selections as required. The options are: •

Stream Method, which defines the method used to mix the component property values to produce a value for the stream.

•

Stream Basis, which specifies whether the component values will be mixed using their mole, weight or liquid volume fractions.

•

Component Blend, which defines the way in which missing data are handled when calculating properties from blended assay streams.



Click Data... to enter data for this property, for this thermodynamic system. If the Stream Method is defined as User-Formula, the User Formula Data Entry window opens. Otherwise, the Refinery Inspection and User-defined Special Properties Data Entry window opens.



In the Refinery Inspection and User-defined Special Properties Data Entry window, for each component, enter either a Data value or an Index value. If an Index value is entered, Reference Index Data must also be entered.



In the User Formula Data Entry window, for each component, enter a Data value, which will be passed to a linked User-added Subroutine. Up

Chapter 8


to twenty real and integer values can also be passed to the subroutine. The meaning of the data is determined by the calculation subroutine. Note: If you have assigned Refinery Inspection Properties to a Thermodynamic method set, the standard Stream Data Report will include these Refinery Inspection properties.

Printing Refinery Inspection Properties and User-defined Special Properties Refinery Inspection Properties and User-defined Special Properties can be included in the PRO/II output reports. 

Select Report Format from the Output menu. Next, select the Miscellaneous Data... menu option. The Miscellaneous Report Options window appears.



In the Refinery Inspection and User-defined Special Properties box, check one or both of the following options: Include Input Data —for a printout or data that has been input and/or Input Program Data —for a printout of data generated by PRO/II.

For output of kinematic viscosity data: 

Select Report Format from the Output menu. Next, select the Stream Properties... menu option. The Stream Property Report Options window appears.



Enter two temperatures at which the kinematic viscosity results are required.

BVLE (Validating Equilibrium Data) Tables and plots of binary equilibrium data for given pairs of components may be generated in order to ensure that they are valid in the required range of operation. Any thermodynamic VLE or VLLE K-value method may be used. For liquid activity thermodynamic methods (e.g., NRTL or UNIFAC), the following are calculated: •

K-values,

•

Liquid activity coefficients,

•

Vapor fugacity coefficients,

•

Vapor pressures, and

•

Poynting correction.


April 2014

For non-liquid activity methods, such as equations of state or generalized correlations, the following are determined: •

K-values,

•

Liquid fugacity coefficients, and

•

Vapor fugacity coefficients.

The validation is carried out in the PRO/II - Binary VLE/VLLE Data window which is opened by selecting the Binary VLE option from the Tools menu or by clicking BVLE toolbar. This window is only available when at least two components and a thermodynamic method have been selected. To generate a BVLE plot or table: •

from the Tools menu or click BVLE toolbar to bring up the Select PRO/II - Binary VLE/VLLE Data window.

•

Click TDM Calculated BVLE to view Component and Thermodynamic dialog box. Users can view all the components that have been used in the current flowsheet on the left-hand side of this dialog box. Use Diagram Tab to calculate and view the BVLE plot and its associated data in the Excel sheet format. Here, BVLE plots can be viewed similar to PRO/II, but this plot uses TDM and Modular Thermo Data.

•

Select the required components for the equilibrium calculations from the drop-down lists.

•

Next, select constant pressure or temperature operation and enter the value.

•

Finally, click Calculate to generate plots (by default, all available plots will be generated). If Excel is selected on the Plot Setup option, from the Options menu, tabular data are available in the spreadsheet. Otherwise, only the plots are shown.

Note: For complete technical details, see the Utilities topic in the PRO/II Reference Manual.

Chapter 8


Chapter 9 Unit Operations and Utility Modules This chapter describes how to use unit operation models. Also described are the use of utility modules such as the Calculator, Controller, Flowsheet Optimizer and similar functionalities. For ease of reference, both the unit operation models and the utility modules are presented. Simply +click the hyperlinked name to go to the proper page. Calculator……………………….. 143

Heat Exchanger, Simple ………... 256

CAPE OPEN…………………………163 Heating/Cooling Curves …………. 260 Column, Batch………………………167 Mixer ………………………………… 269 Column, Distillation ……………....168 Multivariable Controller …………. 270 Column, Liquid–Liquid Extraction Phase Envelope …………………... 272 …………………………………………185 Column, Side ……………………... 190

PIPEPHASE Unit Operation …….. 273

Compressor.……………………..….192 Pipe …………………………………. 276 Controller ……………………………196 Polymer Reactor ………………….. 281 Counter Current Procedure Data …………………… 282 Decanter……………………………..198 Crystallizer…………………………..199 Pump ……………………………….. 290 Cyclone ……………………………. 202

Reaction Data ……………………... 291

Rotary Drum Filter…………………208 Reactor …………………………….. 294 Solids Dryer…………………………210 Plug Flow Reactor………………….297 Melter/Freezer……………………….212 Unit Reaction Definitions…….……302 Depressuring Unit………………….213 Reactor, Batch ……………………. 307 Dissolver ………………….…………219 Solid Separator …………………… 308 Filtering


Splitter ……………………………… 309

April 2014

Centrifuge………..…..…................220 Excel Unit…………………………....227 Stream Calculator ………………… 310 Expander ………………………….. 233

Specifications ……………………... 312

Flash ……………………………….. 235

Vary……………………………………315

Flash With Solids ………………... 238

Define…………………………………317

Flowsheet Optimizer ……………. 239

User-added Unit Operations ……. 329

Heat Exchanger, LNG …………… 244

SimSci Add-on Modules…………..337

Heat Exchanger, Air Cooled……..246 Valve ………………………………… 340 Heat Exchanger, Rigorous ………247 Wiped Film Evaporator ………….. 341

Calculator

General Information The Calculator is a versatile utility module useful for a variety of purposes in flowsheet simulation. Parameters are retrieved from the flowsheet and calculations are performed using a FORTRAN-like language or Microsoft Excel. Parameters may be returned to the flowsheet for use by other unit operations. Some uses for the Calculator include: 

Calculating special stream properties



Simulating special processing units such as reactors



Determining operating conditions for other unit operations



Performing design calculations using flowsheet information



Producing special output values for reports



Computing utility costs and economic functions



Calculating target values for Controllers or objective functions for Flowsheet Optimizers

This is by no means an exhaustive list; the usefulness of this module is limited only by the ingenuity of the user.

Chapter 9

Unit Operations and Utility Modules 143

Calculator Setup In the setup section, unit and stream parameters are retrieved from the flowsheet, constants are defined, names are assigned to calculated results, a sequence table is set up for the streams used for input and output, and the dimensions for the various working arrays may be expanded if desired. Start Setup by clicking Edit/View Declarations on the Calculator main data entry window to open the View Area: 

Click Parameters… to retrieve flowsheet parameters into the Calculator. These variables are accessed in the Calculator procedure as elements of array P. Click the Calculator parameter linked text to open the Definition window where you can specify the stream or unit flowsheet parameter to be retrieved. The format for this window is identical to that used for the DEFINE and is described in the SPEC/VARY/DEFINE section of this chapter. In this window, you will find a list of the unit and stream parameters that may be retrieved via DEFINE.



Click Constants… to enter the constant values. These variables are accessed in the Calculator procedure as elements of array C. Although you can enter constants directly in the procedure, this array provides a means for collecting constants that need to be updated occasionally into a common location.



Click Results… to enter names for the Calculator results. These values are accessed in the Calculator procedure as elements of array R. These names will be used in the output report.



Click Stream Sequence… to define an ordered table of flowsheet streams. There are two functions for this table. First, it provides a necessary link between the procedure and the flowsheet streams for information flow. Second, a calculation loop may be performed in the procedure for a range of streams, using the positions of the streams in the table to control the loop order.



Click Arrays… to declare the length of the storage arrays used by the Calculator. These arrays include the P, C, R arrays defined above, and the IS array that is used to hold stream variables. This array is described in the Calculator Procedure discussion. Two additional arrays appear here. In earlier versions of the Calculator, all local variables had to reside in one of these arrays, V for real variables and IX for integers. Now that any valid FORTRAN variable name can be used, these arrays are no longer needed. Nonetheless, they are still available so that older Calculators will work without rewriting.

Once Setup is complete, click Hide Declarations to close the View Area.


April 2014

Calculator Procedures Use one of the following procedures to perform the calculations. •

Excel Procedure

•

PRO/II Procedure

Excel Procedure In the Excel procedure, the specified parameter, constant, stream data, and component properties are transferred to a Microsoft Excel spreadsheet, which invokes a user-defined macro to perform the calculations and sends the results back to PRO/II in R[] array. Other unit operations and streams can refer to the results using the Define system. An Excel spreadsheet template is provided along with the PRO/II application. It has two worksheets, Parameter worksheet and Component worksheet, which are used to transfer data from PRO/II to Excel, and vice versa. All the values are saved according to the UOM set customization in the spreadsheet. Note: You can customize the spreadsheet to include new macro and new formulas. To use the Excel procedure 

In PRO/II, double-click the calculator unit operation module.



Select the Use Excel Procedure check box.



Select the required Thermodynamic System from the Thermodynamic System drop-down list box.



In the Excel Procedure section, enter the details pertaining to the following fields. •

Spreadsheet Name: Browse and select the spreadsheet required for performing the calculations.

•

Worksheet Name: Enter the name of the worksheet that contains fields for calculating and displaying parameters. If the worksheet name is not entered, P2Parameter is used by default.

•

Component Sheet: Enter the name of the worksheet that contains fields for calculating and displaying components. If the Component sheet name is not entered, P2Component is used by default.

•

Macro Name: Enter the name of the macro defined in the spreadsheet for performing the calculations. If the macro name is not entered, Macro 1 is used by default.

Chapter 9


Note: If the information entered in any of the above fields is incorrect, an error message is displayed. 

Select any of the following check boxes, as necessary. •

Display Excel during calculations: Select this check box to display the Excel spreadsheet while calculations are performed.

•

Save Excel after calculations: Select this check box to save the Excel spreadsheet after the calculations are performed.

•

Keep Excel open after calculations: Select this check box to keep the Excel spreadsheet open after the calculations are performed.



Edit the spreadsheet by clicking Edit.



Click OK.



Run the simulation.

Limitations of the Excel Procedure The Excel procedure has the following limitations: •

The Excel macro cannot make any direct function calls to transfer data from Excel to PRO/II. All communications with PRO/II take place using the Excel spreadsheet.

•

In the Excel spreadsheet, during the macro run, PRO/II COM Server functions cannot be used to access data in the current flowsheet.

Data Transfer Sheet The Excel spreadsheet used to transfer data from PRO/II to Excel, and vice versa has a standard format, described in the following table. Asterisk mark (*) indicates that the number of columns or cells can increase based on the stream selection. Column or Cell B2 “P2Parameter”

Contents *

During the calculation, PRO/II fills this cell with the parameter sizing.

D2 “P2Parameter”

During the calculation, PRO/II fills this cell with the constant sizing.

F2 “P2Parameter”

During the calculation, PRO/II fills this cell with the result sizing.


April 2014

H2 “P2Parameter”

During the calculation, PRO/II fills this cell with the number of streams.

B4:Bn “P2Parameter”

During the calculation, PRO/II fills these cells with the parameter values.

D4:Dn “P2Parameter”

During the calculation, PRO/II fills these cells with the constant values.

F4:Fn “P2Parameter”

The relevant values are filled in these cells during the macro run and are transferred to PRO/II.

H1 “P2Parameter”

During the calculation, user can select the UOM set in this cell and all the values are converted and displayed based on the UOM set.

H4:Hn “P2Parameter”

*

B2 “P2Component” B(6:noc):H(6:noc) “P2Component”

During the calculation, PRO/II fills these cells with the stream data like molar rate, temperature, pressure, enthalpy, liquid fraction, water fraction, compressibility, Molecular weight, Specific Enthalpy, Mass flow rate, Volume flow rate and component mole fractions. After macro run, if there is any change in the molar flow rate, temperature, pressure, mass flow rate and volume flow rate, the modified values are re-flashed in the relevant streams by PRO/II. During the calculation, PRO/II fills this cell with the number of components. During the calculation, PRO/II fills these cells with the component properties.

Rules for Transferring Data between Excel Spreadsheet and PRO/II •

In the Excel spreadsheet, if formulae are available for Molar rate (total or component), Mass rate, Volume rate, Temperature, or Pressure in the respective cells, their values are not transferred from PRO/II to Excel. •

Chapter 9

If the result of formula or macro for Molar rate (total or component), Mass rate, Volume rate, Temperature, or Pressure is different from the value available in PRO/II, Special Stream functions such as


SRXSTR are automatically used by PRO/II to re-flash the changed values in the respective streams. •

After running the macro, if the cells for total Molar, Mass, or Standard liquid rates are empty in the Excel spreadsheet, they are ignored while transferring data to PRO/II.

•

In the Excel Spreadsheet, if there is a change in any or all the flow rates (Component, Total Molar, Total Mass, and Total Standard liquid rate) of a stream, the data is transferred from Excel spreadsheet to PRO/II in the following order: •

Individual component flow rates are updated and normalized.

•

Total molar flow rates are updated. Individual component flow rates are changed proportionately.

•

Total Mass flow rates are updated. Individual component flow rates are changed proportionately.

•

Total Volumetric flow rates are updated. Individual component flow rates are changed proportionately.

Note: In the Excel spreadsheet, modification of individual component flow rates for Assay and Spiral streams is not recommended.

PRO/II Procedure In the Procedure section, all the calculations are performed using a simple language based on FORTRAN 77. The language permits the use of mathematical functions, branching and looping, and assignment statements commonly used in programming. Special intrinsic functions are available for retrieving flowsheet component and stream information. Special subroutines are provided for storing calculated results directly in flowsheet streams. Calculated results may also be stored in the “Results” array, making them available to the other unit operations in PRO/II. A special solution “flag” is provided for use when a Calculator models a unit operation. Note: The PROCEDURE section must end with a RETURN statement. The FORTRAN procedure is entered directly into the Procedure field on the Calculator main data entry window. The procedure may be checked as is it composed by clicking Check Procedure. The supported features of the language are discussed in the following sections.


April 2014

Elements of the Language Each statement may contain up to 80 characters. The ampersand (&) at the end of a line denotes continuation of a statement on the following line. Note that an asterisk (*) is not valid as a continuation marker, since it signifies multiplication. All lines of code except the PROCEDURE statement may be preceded by a unique numeric label from 1 to 99999 (shown as ‘‘nn’’ in this manual). A dollar sign ($) causes all following characters on the remainder of the line to be interpreted as a comment rather than as code. Unlike in FORTRAN, a ‘‘C’’ in column one does not designate a comment statement.

Predefined Variables Definitions of predefined variables, including default dimensions for arrays, appear in the following table. Use a DIMENSION statement in the Calculator setup section to reset the number of elements in each array. Arrays C, P, V, and R store values in floating-point form. Array IX stores integer values. Forms of use include: An where A is any of C, P, V, R, or B, and n is an integer that indicates a single element of the array. A(index) A is any of C, P, V, R, or B, and (index) is an expression, such as (IX2 * 5). The parentheses are required. “A(n)” denotes the same element as “An”. Instead of, or in addition to the supplied V and IX arrays, standard FORTRAN variables may be used. They may be up to 8 characters long and may not duplicate the names of any supplied variables; otherwise they follow the conventional FORTRAN rules. The introduction of this feature in PRO/II 5.0 means that the V and IX arrays need not be used. If this is the case, the arrays can be dimensioned to one word each to save memory. Array "IS" is normally used as the index of a DO loop to step through a sequence of streams in the order defined on the SEQUENCE statement. It may serve as the stream index in PRO/II intrinsic functions. The only form allowed is ISn. IS(index) is never valid. Predefined Variables Variable Name and Form

Chapter 9

Default Size (for arrays)

Description and Comments


Predefined Variables Variable Name and Form


Description and Comments

Cn or C(index)

1<=n<=50

Constant values defined in the setup section. Used only on the right side of assignment statements

Pn or P(index)

1<=n<=50

Flowsheet parameters set by DEFINE statements. Used only on the right side of assignment statements.

Vn or V(index)

1<=n<=200

A floating-point work array used on either the left or right side of assignment statements. These elements are initialized to a large negative value and are not available outside the calculator.

Rn or R(index)

1<=n<=200

The array of calculator results, used on either side of assignment statements. This results vector is available to other flowsheet modules external to the Calculator. These elements are initialized to a large negative value.

IXn or IX (index)

0<=n<=9

An array of integer values. The form IX(index) is invalid on a DO statement. It may be used on either side of assignment statements.

ISn

0<=n<=9

An array of elements used as indices of DO loops for stepping through a series of streams in the order defined on the SEQUENCE statement.

ISOLVE


This variable indicates whether or not the Calculator solved. It is initialized to 0 upon each entry into the calculation procedure. The user assigns all subsequent values using an assignment statement. 0 The Calculator has not yet executed (default) or has solved successfully. 1 The Calculator solved. 2 The Calculator did not solve, but continue flowsheet calculations within a recycle loop. 3 The Calculator did not solve, all calculations stop unconditionally. 4 The Calculator solved; but stops all subsequent flow sheet calculations. This sets

April 2014

Predefined Variables Variable Name and Form


Description and Comments the flowsheet solution flag to ‘SOLVED’.

MAXC

Total number of components in the problem.

MAXS

Maximum number of streams in the problem.

FORTRAN Statements Procedure This statement marks the start of the FORTRAN-based procedure section of the Calculator. It is required.

Declaration Statements REAL

rname1, rname2(i), rname3(j, k)...

INTEGER

iname1, iname2(i), iname3(j, k)...

DIMENSION

name1(i), name2(j, k)...

These statements are used to define local scalars and arrays for use in the code. Each subscript may be an integer constant, or two integer constants separated by a colon to specify both the lower and upper array bounds. When defined by the DIMENSION statement, variables assume the normal FORTRAN convention that assigns names starting with I through N as integers, and all others as real. Name lengths may be 8 characters long. Variables defined here may be changed in the code. Variables not defined here are assumed to be real or integer according to the first character. Variable names must not conflict with any reserved words or predefined variables (see table entitled Predefined Variables). Examples: DIMENSION A(20,20), B(20), X(20) REAL MASS INTEGER COUNT, TAB(100) REAL REVENU(1990:1995), PROFIT(1990:1995), LOSS(1990:1995)

Chapter 9


Note: A variable may only appear once in these statements. The following is valid in standard FORTRAN, but not in a Calculator Procedure: REAL MOLWT DIMENSION MOLWT(50) Both standard FORTRAN and the Calculator accept this equivalent form: REAL MOLWT(50)

Assignment Statements nn variable =expression The “expression” is governed by standard FORTRAN conventions. The operations on a given statement are executed in the following order: 1. Expressions within parentheses ( )

4. Multiplications and divisions ( *, /)

2. Functions

5. Additions and subtractions (+,-)

3. Exponential ( ** ) With the exception of exponentiation, calculations with the same precedence are evaluated from left to right. Multiple exponentiations without parentheses to explicitly specify the evaluation order are not permitted. For example, the following is invalid: BADVAL = A**B**C

Note: The Calculator-supplied arrays C and P may not appear on the left side of an assignment statement.

FORTRAN Intrinsic Functions The FORTRAN intrinsic functions tabulated below can be used in expressions: FORTRAN Intrinsic Functions Arguments Function ABS DIM EXP INT LOG

Description Absolute Value Positive Difference Exponential e Truncation Natural Logarithm


Result

Number

Type

Type

1 2 1 1 1

real real real real real

real real real integer real

April 2014

LOG10 MIN MAX MOD NINT SQRT

Common Logarithm Minimum Value Maximum Value Remainder Nearest integer Square Root

1 >=2 >=2 2 1 1

real real real real real real

real real real real integer real

SIN COS TAN ASIN ACOS ATAN SINH COSH TANH

Sine (radians) Cosine (radians) Tangent (radians) Arc Sine (radians) Arc Cosine (radian) Arc Tangent (radian) Hyperbolic Sine Hyperbolic Cosine Hyperbolic Tangent

1 1 1 1 1 1 1 1 1

real real real real real real real real real

real real real radian radian real real real real

PRO/II Intrinsic Functions The following table lists special functions that allow direct retrieval of stream and component properties. In the table, “cno" represents an integer component number which is an integer constant or variable, “sid” is a stream identifier or ISn value. This identifier must appear on the SEQUENCE statement to be used by a PRO/II intrinsic function. Property values are retrieved in the UOM used for problem input. PRO/II Intrinsic Functions Function

Description of Property Pure Component Properties

CMW(cno) CNBP(cno) CSPGR(cno) CTC(cno) CPC(cno) CVC(cno) COMEGA(cno)

Molecular weight Normal boiling temperature Specific gravity (60F/60F) Critical temperature Critical pressure Critical volume, cc/gm-mole Acentric factor Properties of Components in Streams

Chapter 9


PRO/II Intrinsic Functions Function

Description of Property

SCMF(cno, sid) SCWF(cno, sid) SCVF(cno, sid) SCMR(cno, sid) SCWR(cno, sid) SCLVR(cno, sid) SCGVR(cno, sid)

Molar fraction of component in stream Weight fraction of component in stream Standard liquid volume fraction Molar rate of component in stream Weight rate of component in stream Standard liquid volume rate of component Standard gas volume rate of component Stream Properties

SMR(sid) SWR(sid) SLVR(sid) SGVR(sid) STEMP(sid) SPRES(sid)

Mole rate of stream Weight rate of stream Standard liquid volume rate of stream Standard gas volume rate of stream Stream temperature Stream pressure

Stream Property Storage Subroutines nn CALL SRXSTR(type, value, sid) A call to SRXSTR stores a Calculator vector element as a property of stream “sid”. Values being stored must be computed in the dimensional units used for data input. The resulting stream is flashed at the new conditions to determine its thermodynamic state. type This entry identifies the stream property to store. Available options are tabulated below. Stream Properties Stored by SRXSTR Type=

Description

SMR

mole rate of stream

SWR

weight rate of stream

SLVR

standard liquid volume rate

SGVR

standard gas volume rate of stream

STEMP

stream temperature


April 2014

SPRES

stream pressure

value

This argument supplies or identifies the value of the property to store. It can be a real constant or variable.

sid

The sid entry identifies the stream in which to store the property. It may be any stream identifier listed on the SEQUENCE statement of the setup section, or an element of array IS in the form ISn. For example:

CALL SRXSTR(STEMP, R(14), SR4) SRXSTR stores the value of element 14 from array R as the temperature of stream SR4. nn CALL SRVSTR(type, array, sid, i, j) A call to SRVSTR stores a range of values representing component stream properties from a Calculator array into a stream. The resulting stream is flashed at the new conditions to determine its thermodynamic state. type

This entry identifies the component property to store in the stream. Available options are listed in the following table.

Stream Component Properties Stored by SRVSTR Type=

Description

SCMR

molar rate of component in stream

SCWR

weight rate of component in stream

SCLVR

component standard of liquid volume rate

SCGVR

component standard gas volume rate

array

The initial element of a real Calculator array containing values to store as properties of components in a stream.

sid

The sid entry identifies the stream in which to store the property. It may be any stream identifier listed on the SEQUENCE statement of the setup section, or an element of array IS in the form ISn.

i, j

These two entries are component id numbers. They indicate the first and last components, respectively, for which the property is stored.

For example, 100 CALL SRVSTR( SCWR, V(12), FD1, 2, 5 )

Chapter 9


The statement stores elements V(12) - V(15) as the weight flow rates of components 2 through 5 in stream FD1. Stream FD1 is re-flashed using the new composition with the previous temperature and pressure.

Calculation Flow Control Statements nn GOTO mm This is the standard FORTRAN statement that branches to label mm unconditionally. Writing “GO TO” as two words also is allowed. nn CONTINUE This statement serves as a branch destination or the end of a DO loop. It performs no calculations.

IF Statements nn IF (expression) conditional clause. This statement allows logical branching during calculations and conforms to standard FORTRAN rules for “IF” statements. If the parenthetic expression is true, it executes the conditional clause. The conditional clause may not be one of the following: IF ELSEIF ELSE ENDIF

The following table lists logical operators allowed in the expression. Logical Operators in IF Statements Operator

Description

.EQ. .NE. .LT. .GT. .GE. .LE. .AND. .OR. .EQV.

equal to not equal to less than greater than greater than or equal to less than or equal to both true either true equivalent


April 2014

.NEQV. .NOT.

not equivalent true/false toggle

nn IF (expression) THEN ELSEIF (expression) THEN ELSE ENDIF These statements conform to standard FORTRAN IF-THEN-ELSE statements, allowing for structured branching of code. “ELSE IF” and “END IF” written as two words are also accepted. Block “IF” constructs may be nested.

DO Loops nn DO mm iname= i, j, k This statement defines the beginning of a DO loop having a range extending through statement label mm. “i” and “j” are initial and final indices, respectively. The increment step “k” is optional and defaults to 1. nn DO mm ISn= sid1, sid2 This statement defines the beginning of a stream DO loop having a range extending through statement label mm. ISn is a stream variable, and sid1 and sid2 must be stream ids appearing on the SEQUENCE statement. No incremental step index (comparable to k) is allowed.

OPEN Statement nn OPEN(FILE=fileid, ACCESS=OVERWRITE or APPEND) The OPEN statement opens a file for CALCULATOR output. For PC, VAX, and UNIX platforms, the default output name is fileid.CAL, where fileid is the current input file name. A unique filename of up to 12 characters can be specified, if necessary. It must, however, have a “.CAL” extension. Underscore characters are not allowed (e.g., FILE_01). Any OPEN statement automatically closes the previously opened file.

WRITE and FORMAT Statements nn WRITE (*, format) expression, expression, ... nn FORMAT (item, item, ...) These statements allow output using full FORTRAN format control. Output will be to the file most recently opened with the OPEN statement. The WRITE statement list may include constants, variables, expressions, or array names. Specifying an array name causes all elements of the array to be written.

Chapter 9


The WRITE statement refers to a FORMAT statement defining the output format. The following standard FORTRAN format items are supported.

Format Items Function nIw.d

Output integer data

nFw.d, nEw.dEe, nDw.d, nGw.dEe Output real data ‘xxxxx’, nHxxxxx

Output character constants

Tn, TLn, TRn, nX

Tab control

kP

Scale factor

S, SS, SP

Control of sign output

/, :

Line control

n(...)

Grouping

OUTPUT Statement nn OUTPUT {R(i :j ),P(i :j ),C(i :j ),V(i :j ),IX(i :j ),IS (i :j )} This is a special OUTPUT statement provided with PRO/II. It outputs calculatorsupplied arrays or portions of these arrays to the currently open file. Entries “i” and “j” refer to the first and last elements of the array to be output. If they are absent, the entire array will be output.

DISPLAY Statement nn DISPLAY {R( i :j ),P( i :j ),C( i :j ),V( i :j ),IX(i :j ),IS(i :j )} The DISPLAY statement prints out calculator-supplied array values to the standard report file during calculations. Entries “i” and “j” are defined in the same way as the OUTPUT statement.

TRACE Statement nn TRACE option TRACE statements control printing an historical trace as calculations proceed to facilitate debugging the code in the procedure. Options are: ON

Prints line number, statement number, and (action taken/new variable value) as each statement executes.

BRANCH

Prints TRACE information only for branching statements such as IF, GOTO or DO.

OFF

Turns off all TRACE options.

Examples:


April 2014

TRACE BRANCH Traces branching only. TRACE OFF No trace at all. TRACE ON Traces every statement.

Calculation Termination Statements nn STOP - This statement stops all flowsheet calculations and proceeds directly to the output report. The solution flag for the entire flowsheet is set according to the user-defined value of ISOLVE. nn RETURN The RETURN statement signals the end of the calculation procedure of the Calculator and must appear as the last statement in the procedure section. Only one RETURN statement is allowed. The solution flag for the Calculator is set according to the user-defined value of ISOLVE. RETURN always sets TRACE to OFF.

Sample Calculator Procedures Example 1: Determination of Flash Point Use Nelson’s method to estimate the flash point from D86 distillation characterization data. This sample shows how to calculate the flash points of streams V1, V2, V3, V4, V5, and V6 using the formula: P= 0.64 * (D86(10)+D86(ip))/2.0 - 100.0 where the D86 points are in °F. The final results in °C are stored in R(1) through R(6). Before entering the procedure FORTRAN code, it is necessary to specify the streams (V1 through V6) and establish the two pertinent parameters (the D86 10% and IBP temperatures) for each stream:   

 

Open the Calculator main data entry window by double-clicking the Calculator icon on the PFD. Click Edit/View Declarations to display the View Area box. Click Parameters to display the Parameters data entry table. Enter a number in the Parameter Number data entry field to enable the Calculator Parameter linked text. Click on the linked text to open the Definitions window. Check the Set Up Definition for Calculator Parameter P(1) box to enable the “Calculator Parameter = Parameter” linked text. Click the Parameter… hypertext to open the Parameter window where you can specify whether the parameter will be a constant, a stream parameter or a unit parameter. The Constant/Stream/Unit list box

Chapter 9




 

displays a list with the options “Constant,” “Stream” and the various types of unit operations that have been placed on the flowsheet. For this sample problem, select the Stream option and choose V1 from the Stream Name: drop-down list box. Choosing a stream name enables the Parameter… hypertext. Click the linked text to open the Parameter Selection data entry window. For this sample, choose Distillation Curve from the options in the Parameter window. The center window will now display the available distillation curve options. Select D86 from the distillation curve options and choose the desired cut point (here, 10%) from the Volume Percent Distillate drop-down list box.

This completes the parameter specification for the D86(10%) point of the first stream, V1. Repeat these steps to define the D86(Initial Point) for the first stream, V1, then define the D86(10%) and D86(Initial Point) for the remaining five streams. 

Enter the following code into the Procedure window (at this point, this window should still be outlined in red). DIMENSION D8610(6), D86IP(6) DO10 I =1, 6 $ $ COPY PARAMETERS TO LOCAL ARRAYS, $ CONVERTING TO DEG F D8610(I) = P(2*I-1) * 1.8 + 32. D86IP(I) = P(2*I-1) * 1.8 + 32. $ $ EVALUATE FORMULA D86AVG = (D8610(I) + D86IP(I)) / 2. FP = (D86AVG * .64 - 100. $ $ CONVERT BACK TO DEG C AND STORE R(I) = (FP - 32.) / 1.8 10 CONTINUE RETURN



Commit the code by clicking OK.


April 2014

Example 2: Material Balancing with the Calculator This sample demonstrates the use of the Calculator to compute the material balance of hydrogen (component 2) about a recycle loop. We will set the solution flag to indicate “unit not solved” if the hydrogen balance is not met to within 0.01% based on the overall feeds. This specification forces the recycle to continue iterating, even if the flowing streams have changed less than the flowsheet stream tolerance. See the ISOLVE and ISn entries in the Predefined Variables table on page 152 for a listing of solution flags and for an explanation of the use of the Isn variable in SEQUENCE statements. Before entering the procedure code, we must: 

Establish the Stream Sequence for the recycle loop.



Provide a label for the Result.

Establishing the Stream Sequence: The streams pertinent to this example are a hydrogen feed stream (H2FD), two feed streams (FD1, FD2), a purge gas stream (PURG), and vapor and liquid product streams (PRDV, PRDL). To set up the stream sequence that will be used by the Calculator, carry out the following steps: 

Open the Calculator main data entry window by double-clicking the Calculator icon.



Click Stream Sequence to display two windows, one containing a list of Available Streams and the other a list of Selected Streams.



Add the streams H2FD, FD1, FD2, PURG, PRDV and PRDL in the given order. If you add the streams in the wrong order, you can easily change their sequence by removing the improperly positioned stream from the Selected Streams window and reinserting it before or after the appropriate stream that you have highlighted in the Selected Streams window.

Labeling the Result: 

When you have established the desired stream sequence, click Results to display the Result Number and Print Name data entry table.



Enter “1” in the Result Number field of the first row to enable the Print Name entry field. This integer is stored in the first position of the R() array. For this sample problem, call the result “Relative MB.”



Enter the following code into the Procedure window, which should still be outlined in red at this point:

Chapter 9


$ SUM UP H2 IN FEED STREAMS $ HYDROGEN IS THE SECOND COMPONENT IN THE COMPONENT LIST $ SCMR(2, n) IS THE MOLAR FLOWRATE IN THE nth STREAM $ H2FEED = 0.0 DO 10 IS1 = H2FD, FD2 H2FEED = H2FEED + SCMR(2,IS1) 10 CONTINUE $ $ CHECK IF ANY H2 IN FEED. IF NOT, SET “NOT SOLVED” FLAG. $ IF (H2FEED .LT. 0.0001) THEN R(1) = 0 ISOLVE = 2 GO TO 99 ENDIF $ $ SUM UP H2 IN PRODUCTS $ H2PROD= 0.0 DO 20 IS1 = PURG, PRDL H2PROD = H2PROD + SCMR(2, IS1) 20 CONTINUE $ CALCULATE IMBALANCE $ R(1) = (H2FEED - H2PROD) / H2FEED $ $ CHECK IF IN BALANCE. IF SO, RETURN. $ IF NOT, SET “NOT SOLVED” FLAG. $ IF(ABS(R(1)).LE.0.001) THEN


April 2014

ISOLVE =1 ELSE ISOLVE =2 ENDIF $ 99 RETURN

This page intentionally is left blank.

CAPE-OPEN

General Information The PRO/II CAPE-OPEN unit operation enables the users to add third party CAPE-OPEN units. This will help the user to simulate and perform any type of calculation for a specific unit operation placed in a flowsheet. CO-LaN (the CAPE-OPEN Laboratories Network) is a neutral industry and an academic association promoting open standards in process simulation software. CAPE-OPEN has uniform standards for interfacing process modeling software components developed specifically for the design and operation of chemical processes. These standards allow integration of different software components like unit operations and thermodynamic property packages from different vendors into a single simulation. PRO/II supports both versions of 0.9.3 and 1.0 of the CAPE-OPEN interfaces. The CAPE-OPEN Unit Operation has access to the following: •

Flash and Physical property calculations provided by PRO/II

•

Third party CAPE-OPEN property package.

Property values exchanged between PRO/II and CAPE-OPEN unit operation are in SI units. CAPE-OPEN interface descriptions and information are available at http://www.colan.org/ Note: If transport properties are required in the CAPE-OPEN unit operation, you must select a suitable method in the Thermodynamic Data if PRO/II thermodynamics is selected.

Chapter 9


Installing CAPE-OPEN Unit Operations To install a new CAPE-OPEN unit operation or property package, execute the install program provided by the vendor. The install program should perform all actions necessary to copy the files to your computer and set up the required entries in the Windows Registry. After installation, you can launch PRO/II and immediately use the new CAPE-OPEN software components. If the CAPE-OPEN unit operation does not have an installation program, follow the steps mentioned below to manually register the unit operation. 1. Identify the DLL file of the CAPE-OPEN unit operation. 2. Type "regsvr32 myunitop.dll", where "myunitop.dll" is the name of the DLL of the CAPE-OPEN Unit Operation. 3. Identify the "progid" of the CAPE-OPEN unit operation. The "progid" is a short text string, such as "SimSci.Mixer" that Windows uses to identify the DLL. Contact the developer of the unit operation to determine the "progid". 4. From the command prompt, type "CapeRegister.exe progid". "CapeRegister.exe" is a utility available in the PRO/II "bin" directory.

Selecting the CAPE-OPEN Unit Operation Install the CAPE-OPEN unit operation, as described above, and launch PRO/II to use the new CAPE-OPEN software components. When the new CAPE-OPEN unit operation is laid down on the PFD, a dialog will be displayed with a dropdown list box filled with registered CAPE-OPEN unit operations. The user must select the program ID of the required unit.

Feeds and Products Unit Operation may have multiple feed streams and use the data for various flash and property calculations. PRO/II queries the unit operation for a required number of unit ports. The icon is automatically supplied with the required number of ports with one stream allowed for each port. Note: Material type ports are handled while the energy and information type ports are not supported.

Display Unit Operation on PFD To place a CAPE-OPEN unit operation, double-click the icon on the PFD. If the unit operation supports a custom GUI, the built-in GUI for the unit operation is displayed. If the unit operation does not support a custom GUI, PRO/II displays all parameters in the default data entry window. All values are displayed in SI units.


April 2014

Saving the state of CAPE-OPEN Unit Operations PRO/II supports COM Persistence mechanisms through IStream, IStreamInit, IStorage and IPropertyBag interfaces. PRO/II creates a file named prznameuid.dat for storing state. If CAPE-OPEN Unit does not support COM persistence, PRO/II saves the state of the CAPE-OPEN unit operation by querying all input and output parameters and storing their values in the underlying PRO/II database.

Calculation During calculations, PRO/II calls the Validate() and Calculate() method of the CAPE-OPEN unit operation. Property and flash calculations are delegated to property package if property package is selected as unit thermodynamics. If PRO/II thermodynamics is selected for a CAPE-OPEN unit operation, it may call TP, TH, PH, TV, and PV flashes (CalcEquilibrium) for input or output streams. The following properties can be calculated using PRO/II thermodynamics. CAPE-OPEN identifier

Property meaning

Phases Supported

vaporPressure

Vapor Pressure only for Pure calc type

Liquid

surfaceTension

Surface Tension

Liquid

Compressibility Factor

Compressibility Factor Z= PV/RT

Liquid, Vapor, Overall

heatCapacity

Heat Capacity


idealGasHeatCapacity

Heat Capacity of ideal gas

Vapor

viscosity

Viscosity


Thermal Conductivity



fugacity

Fugacity

Liquid, Vapor

logFugacityCoefficient

Logarithm of Fugacity Coefficients

Liquid, Vapor

kvalues

K factors of a pair of phases in Equilibrium

Overall

dewPointPressure

Dew point Pressure at a given temperature

Overall

Chapter 9


CAPE-OPEN identifier

Property meaning

Phases Supported

dewPointTemperature

Dew point Temperature at a given Pressure

Overall

temperature

Temperature


pressure

Pressure


volume

Volume


density

Density


enthalpy

Enthalpy


entropy

Entropy


gibbsFreeEnergy

Gibbs Free Energy


flow

List of partial Molar(or mass) flows for each component within a given phase


fraction

List of partial Molar(or mass) fractions for each component within a given phase


phaseFraction

The fraction of the fluid that is in specified phase

Liquid, Vapor

totalFlow

Mass flow of a phase or whole mixture


molecularWeight

MolecularWeight


boilingPointTemperature

Only supported for “Pure” calc type

Report Generation If the custom reports is supported by CAPE-OPEN unit operation, select and right-click the unit operation. This action will display a menu with “Produce Report” as one of the options. Select Produce Report to open a text file.


April 2014

If the custom reports are not supported, the menu will have “View Results” as one of the options. Select View Results to display all input and output parameters with their values. Note: The standard report of PRO/II will have all input and output parameters with their values for CAPE-OPEN units.

Column, Batch

General Information The Batch Column unit operation models a wide range of column operating scenarios. The Batch Column unit may be run in a true batch simulation mode, with the feedstock charged to the stillpot prior to distillation and products taken from the accumulator at various times, or in a semi-batch mode where feedstock may be introduced during distillation and products drawn from the column or accumulator over some time interval. Batch distillation calculations may also be integrated into a steady-state process simulation. The unit configuration automatically considers the presence of implicit holding tanks for continuous flow streams which provide the time-variant feedstock to the batch unit. Implicit consideration of holding tanks for all product streams (as drawn from the accumulator at different times, or as drawn from the column during distillation) is also made because of the cyclic operation. A representation of the product continuous flow stream comes from the amount of product divided by the batch cycle time.

Thermodynamic System The thermodynamic system for the Batch Column may be specified for the unit as a whole or for selected trays. Batch Column also allows the use of electrolyte thermodynamic methods.

BATCHFRAC® ®

This is a batch distillation model obtained from Koch-Glitsch, LP. BATCHFRAC has been integrated with PRO/II to handle reaction on trays for VLE, VLLE on all the stages and heat duty specification for trays apart from Batch distillation. Detailed Information ®

For detailed information about the use of BATCHFRAC and Batch Column unit operations, consult the PRO/II Add-On Modules User Guide.

Chapter 9


Column, Distillation

General Information The Column unit operation may be used to simulate any distillation or liquid-liquid extraction process. Liquid-liquid extraction units are described in the LiquidLiquid Extraction Column section of this chapter. A column must contain at least one equilibrium stage or theoretical tray. For purposes of this discussion, the term “trays” is used to denote “equilibrium stages”. The trays are considered to be linked with the vapor from each tray entering the next higher tray and the liquid from each tray feeding the next lower tray. There is no limit on the number of trays in a column model. The condenser, when present, is always numbered as tray one and the reboiler, when present, is assigned the highest tray number in the model. Any tray may have a feed, product draw, or duty. The top and bottom trays must have either a feed or a duty. Distillation columns may simulate vapor/liquid, vapor/liquid/water or vapor/liquid/liquid equilibrium processes.

Feeds and Products Column feeds and products are added during the flowsheet construction in the PFD main window. Click Column Feeds and products… on the Column main data entry window to open the Column Feeds and Products window. Feed tray numbers may be added or changed in this window. There is no limit on the number of feeds a column may have. The feed flash convention to use for all feeds to the distillation column is selected with radio buttons as: Vapor and liquid to be on the feed tray: The default. Flash the feed adiabatically, vapor onto the tray above and liquid onto the feed tray. For this option, the vapor is placed on the feed tray when it is the bottom tray of the column. For products, the product type, phase, tray number, and flow rate are supplied in this window. There is no limit on the number of products a distillation column may have and products may be withdrawn from any tray of the column. Product types include: Overhead, Bottoms, Fixed Rate Draw, Total Phase Draw, and Pseudoproduct. Every column must have an overhead product leaving tray one and a


April 2014

bottoms product leaving the highest numbered tray. The Sure, Inside-Out (IO) and Enhanced IO algorithms may have a decanted water product from tray one (the condenser). The Sure algorithm may also have water draws from any tray. For vapor/liquid/liquid equilibrium (VLLE) processes, either of the liquid phases may be drawn from any tray in the column. You must supply product rates for all fixed rate draw products in molar, mass, or liquid volume units. You must also provide an estimated value for either the overhead or bottoms product. For total draw products, the supplied rate is always assumed to be an estimate. The estimated value for the overhead or bottoms rate should be as accurate as possible to enhance convergence. You must use a Performance Specification to set a desired flow for the overhead or bottoms product.

Pseudo-products Pseudo-products are used to create streams corresponding to column internal streams, making them available for flowsheet calculations. Define pseudoproducts in the Column Pseudo-products window which you may reach by clicking Pseudo-products on the Column Feeds and Products window. The following types of pseudo-products are available: 

Net tray liquid or vapor flow



Total tray liquid or vapor flow



Pumparound liquid or vapor bypass flow



Thermosiphon reboiler feeds and products

Thermosiphon reboiler streams are limited to the Inside-Out algorithm.

Column Algorithm Select the solution algorithm from the drop-down list box, on the Column main data entry window. The available algorithms are: Inside-Out (the default), Sure, Chemdist, Liquid-Liquid, Enhanced IO, and Electrolytic. Detailed information about the column algorithms is available in the online help. Inside-Out: The Inside-Out algorithm is the preferred option for most distillation problems, especially those involving systems of hydrocarbons, because of its speed and insensitivity to the estimated solution profiles. Sure: The Sure algorithm should be used for columns where free water exists on multiple trays. Chemdist: The Chemdist algorithm is well suited to highly non-ideal systems and VLLE processes.

Chapter 9


Liquid-Liquid: The Liquid-Liquid algorithm is used to model liquid-liquid extraction units described in the Liquid-Liquid Extraction Column section of this chapter. Enhanced IO: The Enhanced IO column algorithm extends the capabilities of the default Inside-Out algorithm. Enhanced IO allows zero flow rates, water decant off any tray, total draws from trays and pumparounds. Electrolytic: The Electrolytic method is used to model non-ideal aqueous electrolytic distillation columns involving ionic species. Refer to the PRO/II Add-On Modules User Guide for detailed information on this column algorithm. ®

®

RATEFRAC Software: Rate-based distillation (RATEFRAC ) routines rigorously calculate the actual mass transfer on the stage, avoiding the need for component efficiencies. The non-equilibrium stage model used ® in RATEFRAC is a “rate-based” model. That algorithm uses fundamental heat and mass transfer calculations to model a distillation stage. ®

RATEFRAC is a registered trademark of Koch-Glitsch, LP.

Reactions Reactions in the column can be modeled by the Chemdist or Liquid-Liquid ® extraction and RATEFRAC algorithms found in the Algorithm drop-down list of the Column window. Enter pertinent data in the Column – Reaction Selection window accessible via the Reactions… button on the Column window. In the Column - Reaction Selection window, you can select and modify column reactions, specify stage-wise reacting volumes, designate non-condensable components, select non-volatile catalysts and specify data for user-added subroutines or kinetic procedures. The reactions specified here are limited in scope to the simulation of reactive distillation and (reactive) liquid-liquid extraction.

Column - Reaction Selection To modify reaction sets defined in Reaction Data, select the Include Reactions in Column Calculations check-box. All the reactions defined via Input/Reaction Data are now available to the column. Reactions can be selected from a drop-down list under Reaction Set from Reaction Data, and a local set-name and description can be assigned. Moreover, the individual reactions can be modified in the Reaction Definitions window by clicking Modify Data. The selected reaction sets can also be assigned to individual trays (or ranges of trays) by selecting reaction sets from a drop-down list under Column Reaction Set and then entering a tray range, i.e., starting tray to ending tray.


April 2014

Note: Although you can modify a local copy of a reaction set in the column, the original reaction set specified in the ‘Reaction Data’ section remains unchanged.

Reacting Volumes The user can specify volume available for reaction (effective volume) per stage for both liquid and vapor phase reactions in the Column –Tray Effective Reaction Volumes window accessible from the Reaction Selection window. A tabulation of tray numbers and the respective volumes is provided for data entry. This specification is used in calculating the rate of kinetic reaction. For Ratefrac column, user can specify segment volume percents of both liquid and vapor. This data is used in non-equilibrium calculations of Ratefrac. Data supplied on only one tray will be copied to all other trays and data supplied to multiple trays will be interpolated to any missing trays during calculations.

Nonvolatile Catalyst Components that catalyze a reaction without volatilizing can be selected and the quantity of their charge specified as an amount or a fraction in the Column - NonVolatile Catalyst for Boiling Pot window accessible from the Column - Reaction Selection window.

Non-condensable Non-condensing components can be specified in the Column - Non-Condensing Components window accessible from the Column –Reaction Selection window.

Subroutine/Procedure Data Data used for user-added subroutines and kinetic procedures can be specified in the form of Integer, Real and Supplemental Data entries in the Column - User Subroutine and Procedure Data window accessible from the Column - Reaction Selection window via the Subroutine/Procedure Data button. See the Reaction Data and Procedure Data sections, in this chapter, for detailed information on the data requirements for these utility modules.

Modify Data (Reaction Data) All data pertaining to a reaction (in a specified reaction set) can be modified except for reaction stoichiometry - in the Column-Reaction Definitions window accessible via Modify Data… in the Column-Reaction Selection window. The calculation method for a reaction can be modified to follow a user-added subroutine, procedure or kinetic power-law expression. The reaction type can also be changed to Kinetic, Equilibrium or Conversion. All reaction data that completely specify any of the above reaction types (except stoichiometry) can be

Chapter 9


changed in the data entry fields accessible via the Enter Data… button under the Additional Data column for the respective reaction. Instructions for entering data for the three types of reactions (Kinetic, Equilibrium and Conversion) are covered in detail, in the Reaction Data section of this chapter.

Calculated Phases Select the appropriate phase system in the drop-down list box on the Column main data entry window. All distillation algorithms support the default phase system of vapor/liquid. The Sure and Chemdist algorithms also support the vapor/liquid/liquid system. In addition, the Sure and Enhanced IO algorithms support the phase system vapor/liquid/water that allows a free water phase on any tray of a column.

Number of Trays Enter the number of trays in the model, in the data entry field provided on the Column main data entry window. Every Column must have at least two trays. There is no limit on the number of trays in a Column.

Number of Iterations Supply the number of iterations in the data entry field provided on the Column main data entry window. The number of iterations corresponds to the number of outer loop trials for the Inside-Out algorithm and the number of trial solutions for the other algorithms. A non-convergence is flagged when this number of iterations is performed and the column equations are not satisfied within the tolerances. The default values are 15 for the Inside-Out algorithm, 10 for the ® Sure algorithm, 20 for the Chemdist algorithm, and 30 for the RATEFRAC algorithm.

Pressure Profile The pressure for every tray in a column model must be defined. All calculations are performed at the defined tray pressures. Define the tray pressures in the Column Pressure Profile window which you may reach by clicking Pressure Profile… on the Column main data entry window. Tray pressures may be supplied on an overall or tray-by-tray mode by choosing a radio button in this window. For the overall mode, supply the top tray pressure (tray two for columns with condensers) and either the pressure drop per tray or the total pressure drop across the column. A default value of zero is supplied for the pressure drop per tray and the column pressure drop. All tray pressures are derived by linear application of the supplied pressure drop.


April 2014

Individual tray pressures are supplied for the tray by tray mode. Note that the top and bottom trays must be included when supplying a table of individual tray pressures. Missing pressures are determined by linear interpolation of supplied values. This method is useful for defining the pressure profile for columns with irregular pressure profiles such as refinery vacuum units.

Condensers The condenser is always a heat sink on tray one. It is defined in the Column Condenser window, which you may access by clicking Condenser… on the Column main data entry window. The top products from columns with condensers correspond to the products from the reflux accumulator drum. The pressure for all types of condensers is supplied in this window. The condenser type is selected with the appropriate radio button from the following options: Partial: This condenser is an equilibrium stage and may or may not have a net liquid product as well as vapor product. The net liquid product, if present, is defined as a “Fixed rate liquid draw” from tray one. The condenser temperature is the dew point of the equilibrium vapor. An optional estimate for the condenser temperature may be supplied in the Column Condenser window. The condenser pressure and duty may also be supplied. Bubble Temperature: The vapor from tray two is cooled to a bubble point liquid phase. While one portion is returned as reflux to tray two, the other portion is withdrawn as the “Overhead” product from the column. An optional estimate for the condenser temperature may be supplied in the Column Condenser window. The condenser pressure and duty may also be supplied. Subcooled, Fixed Temperature: The vapor from tray is cooled below its bubble point as defined by a subcooled temperature provided in this window. PRO/II ascertains that the product is subcooled, and if, not, signals a non-convergence condition with an appropriate diagnostic message. The subcooled liquid product is designated the “Overhead” product from the column. The condenser pressure and duty may also be supplied. Subcooled, Fixed Temperature Drop: This condenser is the same as the subcooled type described above except that the degrees of sub cooling below the product bubble point is defined, always resulting in a subcooled “Overhead” product. The duty and pressure for the condenser may also be supplied in this window, if desired. If the duty is designated as a parameter to vary, any supplied duty for any of these condenser options is used as an estimate.

Chapter 9


Sub-cooled Reflux Only: This option is enabled only by selecting Partial or Bubble Temperature under Condenser Type. Select the appropriate Temperature specification namely, Fixed Temperature or Temperature Drop that needs to be followed in the Subcooled reflux for the chosen condenser type.

Reboilers Column reboilers are described in the Column Reboiler window which is entered via the Reboiler button on the Column main data entry window. The reboiler type is selected with a radio button on this form. The default type is the Kettle (Conventional) reboiler, which corresponds to a duty on the bottom tray of the column with the equilibrium liquid withdrawn as the “Bottoms” product. For both Inside-Out and Enhanced IO algorithms, following reboiler types are available to the user. •

Thermosiphon without Baffles, and

•

Thermosiphon with Baffles.

For other algorithms, only default type is made available to the user. The thermosiphon without baffles type corresponds to the case when the Column bottom product and reboiler feed are withdrawn from a common sump. Note: Thermosiphon reboilers with baffles in which the reboiler return flows into the reboiler sump and overflows to the product sump are equivalent to the “no baffles” type for simulation purposes and should be modeled as such. One specification may be selected for thermosiphon reboilers by choosing the appropriate radio button and entering a value in the field provided. Choices include: •

Reboiler return liquid fraction

•

Return temperature

•

Temperature change across the reboiler

•

Reboiler circulation rate.

An estimate for the return fluid liquid fraction or circulation rate, as is applicable, may be given to enhance convergence. The duty for the reboiler may also be supplied in this data entry window, if desired. If the duty is designated as a parameter to vary, any supplied duty is used as an estimate.


April 2014

Heaters and Coolers Side heaters and coolers may be supplied via the Column Side Heaters/Coolers window accessible via the Heaters and Coolers… button on the Column main data entry window. Side heaters and coolers that are associated with a pumparound are not entered with this window. A negative duty indicates cooling; a positive duty is used for heating. There are no limits on the number of side heaters/coolers. ®

RATEFRAC routines support heating and cooling for both phases (Liquid/Vapor). For each side heater/cooler, the following information must be provided: tray number, a reference name, and the duty, with the appropriate algebraic sign.

Flash Zones The Flash Zone calculation models a fired heater added to a tray in an Inside-Out column. Flash zones are associated with column heaters when a feed stream entering the column is heated in a separate furnace. The furnace is considered as an additional theoretical stage. Liquid from the tray above the flash zone or vapor from the tray below the flash zone could enter the flash zone or they can bypass it. Data entry fields for flash zones can be accessed through the likenamed button on the Heater data entry window. Specification options include fired heater efficiency, vapor and liquid by-pass fractions and transfer line temperature drop. ®

Note: If you are working with RATEFRAC , this option is disabled.

Column Heat Leaks Column heat leaks may be modeled by clicking Heat Leak on the Column Side Heaters/Coolers window to open the Column Heat Leak window. The heat leak may be designated as: •

Overall, or,

•

By Individual Trays

For the Overall option, the heat leak duty for all of the trays except the reboiler and condenser is given on a per tray basis or total column basis. A heat leak may also be provided for the condenser and the reboiler, if desired. For the By Individual Trays option, heat leak duties for ranges of trays are supplied as tabular input. At least two values must be supplied. Heat leaks for trays not given, but which lie between trays with defined heat leaks, are determined by linear interpolation. ®

Note: If you are working with RATEFRAC routines, this option is disabled.

Chapter 9


Pumparounds and Vapor Bypasses Column pumparounds and vapor bypasses may be defined for the Inside-Out and Sure algorithms in the Column Pumparounds window, which is accessed via the Pumparounds… button on the Column main data entry window. A pumparound may be either a liquid or vapor, with vapor pumparounds more commonly termed “bypasses”. Pumparounds are added and edited in a tabular form by clicking on hypertext strings. Entries for each pumparound include: phase, pumparound name, draw tray, return tray, return pressure, and two specifications. Supply these specifications in the Column Pumparound Specifications window which is entered by clicking the two specifications hypertext string. The following specification combinations are selectable via radio buttons: Rate and Duty: The rate and duty data entry fields are enabled for input. A reference name may also be supplied for the heater. Rate without Heater: The rate field only is enabled for input. Rate and Return Condition: The rate and return condition fields are enabled for input. The return condition may be the temperature or the temperature drop or the liquid fraction. A reference name may also be supplied for the heater. Duty and Return Condition: The duty and return condition fields are enabled for input. The return condition may be the temperature or the temperature drop or the liquid fraction. A reference name may also be supplied for the heater. For the Sure algorithm only, the pumparound rate may be designated as the total fluid leaving the tray. Total liquid pumparounds must pump down the column and total vapor pumparounds (bypasses) must flow up.

Initial Estimates All column algorithms use an iterative solution technique, starting from an initial estimate of the tray temperature, flow and composition profiles. The initial estimate may be produced internally using an initial estimate generator and/or provided by the user as initial profile data. User-supplied profiles may also be used to selectively replace values produced by an estimate generator. Click Initial Estimates on the Column main data entry window to enter the Column Initial Estimates window. To use an initial estimate generator, select the generator method from the drop-down list box. Methods provided are:


April 2014

Simple: Profiles are determined by a simple material balance. Temperatures are determined from estimated product compositions. This model is quick and adequate for simple column configurations. Conventional: A general method designed to produce an adequate estimate for most distillation problems. Shortcut calculations are used to estimate the product flows and compositions. The compositions are used to estimate temperatures. Internal flows are estimated by using the product flows and a reflux estimate. This method works best for conventional fractionators with condensers and reboilers in which classic Fenske techniques provide reasonable results. Special techniques are also included for absorbers and strippers. Refinery: This method is designed for complex refinery columns which have bottom steam instead of reboilers such as crude and vacuum columns, F.C.C. main fractionators, etc. These columns may also have side columns, pumparound cooling circuits, and decanted water at the overhead accumulator. A multi-product shortcut technique developed by SIMSCI is used for these columns. The user-supplied estimates for the product rates are used in the shortcut model. Adjustments in the profiles are made for side coolers. Chemical: This generator should be restricted to highly non-ideal chemical distillation problems. The method is time-consuming and uses successive series of adiabatic flashes up and down the column to establish the tray compositions. When using an estimate generator, you may optionally provide temperature estimates for the following trays: condenser, top tray, bottom tray of column, and reboiler. You may also provide an estimate for the reflux rate or reflux ratio. When no reflux estimate is provided by the user, PRO/II supplies a reflux ratio of 3.0 (which solves many columns). Any supplied data replaces values predicted by the estimate generator. When an initial estimate generator is not used, the minimum data which must be supplied as input profiles are tray temperatures and flows, vapor, liquid, or a combination thereof. Note that the minimum data which may be supplied are the temperatures and flows for the top and bottom trays for the column. While these are the minimum data required, they are rarely adequate to produce an acceptable initial estimate. It may also be desirable to provide solution profiles from a converged solution to speed future calculations with a column model. Initial profiles are entered in tables accessed by clicking the following buttons on the Column Initial Estimates window: •

Net Vapor Rates…

•

Vapor Composition…

Chapter 9


•

Liquid Composition…

•

Tray Temperatures…

•

Net Liquid Rate…

•

Mass Transfer…

Composition estimates may be helpful for highly non-ideal mixtures; however, they are rarely needed for most problems. ®

RATEFRAC Initial Estimate: ®

For RATEFRAC routines, Initial Estimate may be used to perform Initial Estimate. Option is also provided to include design specifications. By default, the Perform Initial Estimate option is checked to provide the user to have an estimate on Temperature and Reflux, etc. Check Include Design Specs in Estimate to include design specifications to be considered during Initial Estimate. Tolerance: Enter the Tolerance value. Liquid/Vapor Flow Transformation: Select the appropriate Liquid/Vapor Flow Transformation from the drop list. •

Standard

•

Square

•

Logarithmic

Performance Specifications Performance specifications or SPEC's may be imposed on a column operation such that product stream flows or properties, column internal flows, column tray temperatures, etc., are at desired values in the solution. For each SPEC, a degree of freedom or VARY must be calculated. For a column, a VARY may be a feed stream rate, heat duty, or the draw rate for a “fixed rate draw.” Furthermore, for convergence to be achieved, there must be a direct effect on all of the SPEC's by the collective set of VARY's. To supply SPEC’s and define VARY’s for a column, click Performance Specifications on the main Column data entry window to access the Column Specifications and Variables window. SPEC’s and VARY’s are entered or edited by clicking on the hypertext strings. PRO/II requires that there be an equal number of SPEC’s and VARY’s. Thus, whenever you add or delete a SPEC, you are required to add or delete a VARY. SPEC’s and VARY’s use the general form in PRO/II and are discussed more fully in the SPEC/VARY/DEFINE section of this chapter. A list of the stream and


April 2014

column parameters which may be used for SPEC’s and VARY’s also is given in that section.

Convergence Data Convergence data include Convergence Parameters, Convergence Tolerances, Homotopy Options for Convergence Specifications and Convergence History (printout options) for Column iterations. These data are entered in the Column Convergence Data window accessible via the Convergence Data… button on the Column main data entry window.

Convergence tuning parameters Damping Factor: Using a damping factor of less than unity often improves convergence when the convergence is oscillating. Refinery complex fractionators should be given damping factors of 0.8. Chemdist columns may require more severe damping. A default value of 1.0 is supplied by PRO/II. Damping cannot be applied to the Sure algorithm. Damping Cutoff: The Chemdist algorithm uses the damping factor cutoff value. The damping factor is only applied when the sum of the errors is -8 larger than this value. A default value of 10 is supplied by PRO/II. Error Increase Factor: This factor limits the increase in the sum of the errors from iteration to iteration. PRO/II supplies a default value of 1.0 for the Inside-Out algorithm or 100 for the Chemdist algorithm. This factor does not apply to the Sure algorithm. Component Averaging Factor: This weighting factor for update of compositions is used for the Sure algorithm. A factor of 1.0 gives equal weight to the current and last set of compositions; a factor of 2.0 gives double weight to the last set of compositions, and so forth. A default value of 0.0 is supplied by PRO/II. Key Component: In rare circumstances, specifying a key component can enhance the convergence for the Sure algorithm. The key component is normally determined by PRO/II but may be specified by the user. Stop if no improvement after 5 iterations: The number of consecutive Sure algorithm iterations allowed without improvement in the solution. You can change the number of iterations by clicking on the hypertext string. Changing this parameter rarely, if ever, results in convergence. Note: The use of tuning factors usually results in an increase in the time required to solve a distillation problem.

Chapter 9


Convergence Tolerances Tolerances for the column equations may also be changed although this should rarely, if ever, be done and never as a means to reach a converged solution. Tolerances are: Bubble Point: The maximum bubble point error for each tray. The default of -3 ® 10 is not used by the RATEFRAC . Enthalpy Balance: The maximum heat balance error for each tray. The default -3 is 10 . Equilibrium K-value: The maximum allowable relative change in a component K-value generated in the outer loop of the Inside-Out algorithm versus -3 the last value used in the inner loop. The default of 10 is not used by ® RATEFRAC . Component Balance: The maximum relative component balance error for -3 each tray. Not used for the Inside-Out algorithm. The default is 10 . ®


Homotopy Options for Convergence on Specification The homotopy option is an aid to converging simulations where the specification is difficult to meet by virtue of the value of the specification (as opposed to the type of specification). The homotopy option was designed for Reactive Distillation where convergence is more complex, but it may be used for any column algorithm. One example of the use of homotopy is to systematically increase tray volumes to very large values, to determine the equilibrium compositions for reversible kinetic reactions. The homotopy option allows you to solve the simulation with an initial value for the specification and then automatically move to the desired final value in a set number of steps. The column is converged at each step. To use the homotopy option for any specification, you must supply the initial value of the specification and the number of intervals to use in moving from the initial value to the final value. You cannot change the final value in this window. The homotopy option may be used for a specification which is varied by a Controller or Flowsheet Optimizer. If Initially is selected under the field entitled Apply During Control Loop (the default), the homotopy iterations will be carried out to meet the given column specification. If the specification value is then changed by another unit operation, the column will solve without homotopy iterations. If Always is selected, the homotopy iterations will be carried out every time the column is re-converged after the specification has been changed. In this


April 2014

case, the initial value will be the last converged specification value, not the supplied value.

Convergence History Printout of the column iterations is useful in the diagnosis of a convergence failure. History printout for the iterations may be requested by selecting the printout level desired for the following options. •

Convergence History Print Level

•

Print Column Profiles in Keyword Input File Form Format

•

RATEFRAC

®

routines Initial Estimate Print Level

®


Tray Hydraulics Tray hydraulic calculations may be used to size new columns and to rate existing tray or packed columns. To perform sizing or rating calculations, click Tray and Packing Data… on the Column main data entry window. For sizing and rating purposes, the column is divided into sections of trays or packing on the Column Tray Hydraulics window. Enter tray/packing sizing and rating information in the Column Tray/Packing Rating or Column Tray/Packing Sizing windows accessible via the Enter Data… button. The Glitsch valve tray method is used to perform the tray calculations. The valve tray results are de-rated by five and twenty percent respectively, to represent the performance of sieve and bubble cap trays. For packed columns, random or structured packings are available, as are various types of metallic and ceramic rings and saddles. For sizing calculations, column diameter for each tray is sized independently to meet the specified or default flooding criteria. The largest diameter in each section is then selected and the entire section is re-rated using the largest required standard diameter. For rating calculations, the percent of flood is calculated for each tray. The feature of multiple sections of trays is useful in representing existing columns, which often have a variety of tray and downcomer arrangements.

Column RATEFRAC® Tray Options ®

Column RATEFRAC routines tray options may be used to select the following •

Vapor and liquid mixing characteristics

•

Correlation used to calculate Mass, Heat Transfer and Interfacial Area.

Chapter 9


Base Segment: Enter the Tray number on which the characteristics need to be set. Base Segment will be made available to the user only if you have selected the following in the Column – Tray Hydraulics dialog box: •

Internal – Tray

•

Calculation Type - Sizing

Liquid/Vapor Mixing: Select the appropriate Liquid/Vapor Mixing characteristics from the drop list: •

Complete

•

Linear

•

Logarithmic ®


The options are explained below: Complete – Select, if there is a complete mixing of liquid or vapor phase in the column. This corresponds to a flat concentration profile across a tray. It is the default value and for most cases provides good results. Linear – This option indicates that there is a linear concentration profile across the tray. Logarithmic – This option indicates that there is a logarithmic concentration across the tray.

Column RATEFRAC® Packing Options ®

RATEFRAC Packing Options may be used to select the following and enter the data required for calculation: •

Vapor and liquid mixing characteristics

•

Correlation used to calculate Mass, Heat Transfer and Interfacial Area

Critical Surface Tension: Enter the Critical Surface Tension, if you have selected Random Packing under Internal in the Column - Tray Hydraulics dialog box. Liquid/Vapor Mixing: Select the appropriate Liquid/Vapor Mixing characteristics from the drop list: •

Complete

•

Linear

•

Logarithmic


April 2014

User needs to enter the above-mentioned data for both Sizing and Rating calculation. ®


RATEFRAC® Transport Calculation Methods ®

RATEFRAC Transport Calculation Methods is used to select a suitable correlation for calculating Heat Transfer, Mass Transfer and Interfacial Area.

Heat Transfer Check Correlation and Select Chilton - Colburn Correlation from the drop-down list to calculate Heat Transfer.

Mass Transfer Check Correlation and select the appropriate correlation name from the dropdown list to calculate Mass Transfer: •

Scheffe & Weiland (Internals - Trays and Sizing calculation type)

•

Chan & Fair (Internals - Trays and Rating calculation type)

•

Rocha 1996 (Internals - Structured Packing and for both Sizing and Rating calculation type)

•

Onda (Internals - Random Packing and for both Sizing and Rating calculation type)

Interfacial Area Select any of the listed correlation to calculate Interfacial Area: •

Scheffe & Weiland (Internals - Trays and Sizing calculation type)

•

Chan & Fair (Internals - Trays and Rating calculation type)

•

Rocha 1996 (Internals - Structured Packing and for both Sizing and Rating calculation type)

•

Onda (Internals - Random Packing and for both Sizing and Rating calculation type)

•

Bravo (Internals - Random Packing and for both Sizing and Rating calculation type)

If the user-defined correlation is available for any of the parameters mentioned above, check Subroutine and select the user-defined correlation from the dropdown list. ®


Chapter 9


Tray Efficiencies All trays in a column model are treated as equilibrium stages or theoretical trays unless one of the tray efficiency models is used. This implies that the user must apply some type of tray efficiency to the actual number of trays in the column, to determine the number of theoretical trays to use in the model. Engineers typically use overall tray efficiency factors based on experience to convert actual trays to theoretical trays. This is almost always the best manner in which to model tray efficiency, since generalized correlations for overall tray efficiency are nonexistent in the literature. For the Inside-Out algorithm, PRO/II provides several tray efficiency models: •

Murphree

•

Equilibrium

•

Vaporization.

For the Chemdist algorithm, only the Vaporization model may be used. However, none of these models predicts the overall tray efficiency. All of the models use an equation or factor to adjust the equilibrium vapor composition leaving a tray. The models are useful for tuning a tray or a few trays in a Column model, but their general application to all trays in a column is not recommended. To use tray efficiencies, click Tray Efficiencies… on the Column main data entry window to enter the Column Tray Efficiency window. Select the efficiency model with a radio button and click Efficiency Data… to begin the tabular entry of tray efficiencies. Tray efficiencies may be given for all components on a tray or selected components on a tray. An overall scaling factor may also be provided to be applied to all tray efficiencies. This factor may be adjusted by a Controller unit to meet a desired SPEC.

Side Columns A column using the Inside-Out or Sure algorithm may have attached Side Columns, where a Side Column is a stripper or rectifier. The Side Column draws feed from the main Column and returns a product to the main Column. A finished product is withdrawn from the Side Column. Side Columns are attached as part of the flowsheet construction in the PFD main window. They may be completed and edited by double-clicking on the side column icon on the PFD. The side column data entry windows are identical to the Column main data entry windows with the exception that irrelevant features are eliminated. The Inside-Out algorithm merges a side column with the main column, for calculations. This simultaneous approach means that the SPEC’s and VARY’s


April 2014

for the main column and side columns need not be balanced provided that the SPEC’s and VARY’s for the total column configuration are balanced. The Sure algorithm solves side columns as separate columns in recycle. This approach is more time consuming, and demands that the SPEC’s and VARY’s for the main column and every side column are balanced. The Chemdist algorithm does not permit side columns.

Print Options Click Print Options… on the Column main data entry window to enter the Column Print Options data entry window. Select the desired report options with the check boxes provided. To request plotted results, click Plot Column Results… and select the desired plots with the check boxes on the Column Plot Options data entry window. ®

RATEFRAC Software Print Options: Click RateFrac… to bring up Print Options dialog box. By default, Calculated HETP for each segment option is checked. Check the other options to make the data available in the generated report.

Thermodynamic Systems A thermodynamic system is required for the equilibrium calculations on each tray. The thermodynamic system may be changed from the global default in the Column Thermodynamic Systems data entry window, which is reached by clicking Thermodynamic Systems… on the Column main data entry window. A single thermodynamic system may be defined for the complete column or different systems may be used in individual sections of the column. If a vapor/liquid equilibrium thermodynamic system is used for part of a column with the Chemdist or RATEFRAC algorithm, additional checks may be performed to determine which trays have two liquid phases by clicking the Test for VLLE or VLE Trays check box. The thermodynamic system is then changed to a vapor/liquid/liquid system for those trays. ®

If you are working with RATEFRAC , tests for VLLE or VLE Trays can be performed by entering appropriate data in Column- VLLE Test Data window. ®


Column, Liquid–Liquid Extraction General Information The Column unit operation may be used to simulate any distillation or liquid-liquid extraction process. Distillation columns are described in the Distillation Column section of this chapter. Although liquid-liquid extraction (llex) columns are

Chapter 9


generally not trayed, the distillation column nomenclature is used and the term tray denotes an equilibrium stage. A Liquid–Liquid Extraction Column must contain at least two trays. The trays are considered to be linked with the light-liquid phase moving up the column and the heavy liquid moving down. There is no limit on the number of trays in a liquid-liquid extraction column model. Any tray may have a feed, product draw, or duty. There must be a feed to the top and bottom trays. Note: Side columns may not be used with liquid-liquid extraction columns. The following distillation column features are not applicable to LLEX columns and will be disabled: •

Condenser and reboiler

•

Pumparounds

•

Tray hydraulics

•

Tray efficiencies.

Feeds and Products Column feeds and products are added as part of the flowsheet construction in the PFD. They may be accessed from the Column Feeds and Products window accessible via the Feeds and Products… icon on the Column main data entry window. Feed tray numbers may be added or changed in this window. There is no limit on the number of feeds a column may have. For products, the product type, phase, tray number, and flow rate are supplied in this window. There is no limit on the number of products a liquid-liquid extraction column may have and products may be withdrawn from any tray of the column. Product types include: Overhead, Bottoms, Fixed Rate Draw, and Pseudo-product. Every column must have an overhead product leaving tray one and a bottoms product leaving the highest numbered tray. The product phase may be Light Liquid (Liquid 1) or Heavy Liquid (Liquid 2). Product rates must be supplied for all draw products. Rates may be supplied in molar, mass, or liquid volume units. An estimated value must also be provided for either the overhead or bottoms product. The estimated value for the overhead or bottoms rate should be as accurate as possible to enhance convergence. It is necessary to use a Performance Specification to set a desired flow for the overhead or bottoms product.


April 2014

Pseudo-products Pseudo-products are used to create streams corresponding to column internal streams, making them available for flowsheet calculations. Pseudo-products are defined in the Column Pseudo-products window accessible via the Pseudoproducts… button on the Column Feeds and Products window. The following types of pseudo-products are available: 

Net tray light or heavy liquid flow



Total tray light or heavy liquid flow

Column Algorithm The solution algorithm is selected in the drop-down list box on the Column main data entry window. The Inside-Out (default), Sure, and Chemdist algorithms are for distillation columns. To specify a liquid-liquid extraction column, select the Liquid-Liquid option.

Calculated Phases When the Liquid-Liquid algorithm is selected, the phase system will automatically be set to liquid/liquid.

Number of Trays The number of trays in the model is entered in the data entry field provided on the Column main data entry window. Every Column must have at least two trays. There is no limit on the number of trays in a Column.

Number of Iterations The maximum number of trial solutions is supplied in the data entry field provided on the Column main data entry window. The default value is 30 for the LiquidLiquid algorithm.

Pressure Profile The pressure for every tray in a column model must be defined. All calculations are performed at the defined tray pressures. The tray pressures are defined in the Column Pressure Profile window, which is reached by clicking Pressure Profile… on the Column main data entry window. Tray pressures may be supplied on an overall or tray by tray mode by choosing a radio button in this window. For the overall mode, the top tray pressure must be supplied and either the pressure drop per tray or the total pressure drop across the column. A default value of zero is supplied for the pressure drop per tray and the column pressure

Chapter 9


drop. All tray pressures are derived by linear application of the supplied pressure drop. Individual tray pressures are supplied for the tray by tray mode. Note that the top and bottom trays must be included when supplying a table of individual tray pressures. Missing pressures are determined by linear interpolation of supplied values.

Heaters and Coolers Side heaters and side coolers may be configured in the Column Side Heaters/Coolers window that is accessed using the Heaters and Coolers… icon on the Column main data entry window. A negative duty indicates cooling; a positive duty is used for heating. There are no limits on the number of side heaters/coolers. For each side heater/cooler, the following information must be provided: tray number, a reference name, and the duty, with the appropriate algebraic sign.

Initial Estimates The Liquid-Liquid algorithm uses an iterative solution technique, starting from an initial estimate of the tray temperature, flow and composition profiles. By default, the initial estimate is produced internally using the initial estimate generator. User-supplied profiles may be used to replace some or all of the values produced by the estimate generator. Click Initial Estimates… on the Column main data entry window to enter the Column Initial Estimates window. When using the initial estimate generator, profiles are determined by a simple material balance. Temperatures are determined from estimated product compositions. You may optionally provide temperature estimates for the top and bottom trays which replace values predicted by the estimate generator, as well as an estimate of the ratio of the liquid flows on tray 1. When the initial estimate generator is not used, the data which must be supplied as input profiles are tray temperatures and flows, either light or heavy liquid, or a combination thereof. Note that the minimum data which may be supplied are the temperatures and flows for the top and bottom trays for the column. While these are the minimum data required, they are rarely adequate to produce an acceptable initial estimate. It may also be desirable to provide solution profiles from a converged solution to speed future calculations with a column model. Initial profiles are entered in tables accessed by clicking the following buttons on the Column Initial Estimates window: Net Vapor Rate…, Vapor Composition…, Tray Temperature…, Liquid Composition…, and Net Liquid Rate… Composition estimates are rarely needed for most problems.


April 2014

Performance Specifications Performance specifications or SPEC’s may be imposed on a liquid-liquid extraction column operation such that product stream flows or properties, column internal flows, column tray temperatures, etc., are at desired values in the solution. For each SPEC, a degree of freedom or VARY must be calculated. For a liquid-liquid extraction column, a VARY may be a feed stream rate, heat duty, or draw rate. Furthermore, for convergence to be achieved, there must be a direct effect on all of the SPEC’s by the collective set of VARY’s. To supply SPEC’s and define VARY’s, access the Column Specifications and Variables window via the Performance Specifications… button on the main Column data entry window. SPEC’s and VARY’s are entered or edited via the hypertext strings. PRO/II requires that there be an equal number of SPEC’s and VARY’s. Thus, when a SPEC is added or deleted, you are required to add or delete a VARY. SPEC’s and VARY’s use the general form in PRO/II and are discussed more fully in the SPEC/VARY/DEFINE section of this chapter. A list of the stream and liquid-liquid extraction column parameters available for SPEC’s and VARY’s also is given in this section.

Convergence Data Convergence data include algorithm tuning parameters, tolerances, and history printout options for Column iterations. Open the Column Convergence Data window via the Convergence Data… button on the Column main data entry window to enter these data. The tuning parameters are as follows: Damping Factor: A damping factor of less than unity usually improves convergence when the convergence is oscillating. A default value of 1.0 is supplied by PRO/II. Error Increase Factor: This factor limits the increase in the sum of the errors from iteration to iteration. PRO/II supplies a default value of 100. Note: The use of tuning factors usually increases the solution time. Tolerances for the liquid-liquid extraction column equations may also be changed although this should rarely, if ever, be done and never as a means to reach a converged solution. Tolerances are: Liquid-liquid: The maximum liquid-liquid equilibrium tolerance (equal to the -3 bubble point tolerance for VLE) for each tray. The default is 10 . Enthalpy Balance: The maximum heat balance error for each tray. The default -3 is 10 .

Chapter 9


Component Balance: The maximum relative component balance error for -3 each tray. The default is 10 . Printout of the liquid-liquid extraction column iterations is useful in diagnosing a convergence failure. History printout for the iterations may be requested by clicking Convergence Data… and selecting the printout level desired.

Print Options Click Print Options… on the Column main data entry window to enter the Column Print Options data entry window. Select the desired report options with the check boxes provided. To request plotted results, click Plot Column Results… and select the desired plots with the check boxes on the Column Plot Options data entry window.

Thermodynamic Options A thermodynamic system which supports liquid-liquid equilibrium is required for the equilibrium calculations on each tray. The thermodynamic system may be changed from the global default in the Column Thermodynamic Systems data entry window which is reached by clicking Thermodynamic Systems… on the Column main data entry window. A single thermodynamic system may be defined for the complete column or different systems may be used in individual sections of the column.

Column, Side

General Information The Side Column unit operation models side strippers and side rectifiers associated with a main Column. The Side Column model is currently restricted to the Inside-Out, Enhanced I/O and Sure algorithms. See Column Algorithm in the Distillation Column discussion (page 191) for further information on these methods. Side Columns always use the same distillation algorithm as the main Column. Multiple Side Columns attached to one main Column are possible and, in fact, are common practice in the petroleum refining industry.

Feeds and Products Side Columns are added to the flowsheet with the Side Column unit icon and attached to the main Column with the feed and product streams. Every Side Column has at least one external product which exits the complex column arrangement.


April 2014

Solution Methods Solution methods for Side Columns vary with the algorithm. The Inside-Out (and Enhanced I/O) algorithm merges the Side Column with the main column and solves the complex column arrangement simultaneously. There are three benefits to this approach: •

The simultaneous method results in more precision in the solution.

•

The simultaneous solution is more efficient and uses less computing time.

•

The simultaneous solution provides more flexible product specifications.

For example, the last benefit permits the use of both a D86 (5%) and a D86 (95%) specification for a side stripper product. To solve this same set of specifications with the Sure method requires the use of a Multi-variable Controller unit wrapped around the main column/side column units. The Sure method solves each side column separately from the main column and uses recycle streams to relate the side column and main column. When using special recycle logic to converge the column/ side column recycle problem, this method has three disadvantages compared to the Inside-Out column simultaneous treatment: •

The solution is less precise since a recycle stream tolerance is used in addition to the column equation tolerances.

•

The recycle approach is much slower.

•

Main column variables (except the main column draw rate) cannot be directly related to the side stripper products. This makes it necessary to use controllers to solve for more than one specification on a side product.

Additional Information on Side Strippers Side strippers are widely used to control the front end volatility (flash point) of liquid products such as diesel, fuel and kerosene. The liquid product is drawn from the main column and charged to the top tray of the side stripper, which typically has 6 to 10 actual trays. A stripping medium (usually steam) is fed to the bottom tray of the side stripper to strip about ten percent of the liquid feed (the lightest material) which is then returned to the main column for further fractionation together with the stripping medium. The stripped liquid is withdrawn from the bottom tray of the stripper as a finished product. Steam side strippers have an overall tray efficiency of about 25 percent and can be represented with two theoretical trays.

Chapter 9


A variation in side stripper design is the use of a reboiler on the bottom of the side stripper to "heat strip" the liquid feed. No stripping medium is used for reboiled side strippers. The advantage of this arrangement is a smaller stripped vapor return stream to the main column which reduces the vapor loading for the main column. Reboiled side strippers have higher tray efficiencies than those which use a stripping medium. Therefore, three to five theoretical trays are typically used to model these strippers. Side strippers do not normally have any other items of equipment such as condensers, pumparounds, side heaters/coolers, etc. Only the Sure method permits the use of a condenser on a side stripper. This capability may be useful when modeling some unusual types of column configurations.

Additional Information on Side Rectifiers Side rectifiers are used to remove heavy materials from vapor draw products by providing a rectification section. The vapor draw from the main column is fed to the bottom tray of the side rectifier which may have a large number of trays. The side rectifier must have a condenser or cooling duty at the top to condense the liquid reflux which is used to rectify the vapor product. The overhead product from the side rectifier is removed as a finished product. The liquid from the bottom tray is returned to the main column for further fractionation. The side rectifier corresponds to the rectification section of a conventional distillation column. An overall tray efficiency of 45 to 55 percent is reasonable for many applications. Side rectifiers do not normally have other items of equipment such as pumparounds, side heaters/coolers, etc. Reboilers are never used for these columns.

Compressor

General Information The Compressor simulates a single stage isentropic compression. Outlet conditions and work requirements may be determined using either adiabatic or polytropic efficiency. Optional tabular input may be used to determine performance from supplied curves for outlet pressure or pressure ratio, head, work, and/or efficiency. An optional after-cooler calculation may be included.


April 2014

Both VLE and VLLE calculations are supported. Multistage compressors may be modeled by linking single stage compressor units.

Feeds and Products A compressor operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. Compressors may have one or more product streams. The product phase condition for units with one product stream is automatically set by PRO/II. For compressors with two or more product streams, the product phases must be specified in the Product Phases window which is accessed by clicking Product Phases… on the Compressor main data entry window. Note that for compressors with after-coolers, the products correspond to outlet conditions from the aftercooler. Product phases allowed include: vapor, liquid, decanted water, heavy liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified.

Pressure, Work, or Head Specification The pressure, work, or head specification is selected from a drop-down list box in the Compressor main data entry window. At least one specification must be supplied for every compressor. Options include: Outlet Pressure: The outlet pressure from the compressor. Pressure Increase: The pressure rise across the compressor. Pressure Ratio: Compression ratio (absolute outlet pressure/absolute inlet pressure). Work: Actual work for the compressor. Pressure Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to outlet pressure in the Compressor Outlet Pressure Performance Curve window. Pressure Ratio Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to compression ratio in the Compressor Pressure Ratio Performance Curve window. Adiabatic Work Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to adiabatic work in the Compressor Work Performance Curve window. Polytropic Work Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to polytropic work in the Compressor Work Performance Curve window.

Chapter 9


Actual Work Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to actual work (efficiency has been applied) in the Compressor Work Performance Curve window. Adiabatic Head Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to adiabatic head in the Compressor Head Performance Curve window. Polytropic Head Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to polytropic head in the Compressor Head Performance Curve window. Actual Head Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to actual head (efficiency has been applied) in the Compressor Head Performance Curve window.

Efficiency or Temperature Specification An efficiency or outlet temperature specification may be selected from a dropdown list box in the Compressor main data entry window. Options are: Adiabatic Efficiency: Compressor adiabatic efficiency in percent. This is sometimes called the “isentropic” efficiency. Polytropic Efficiency: Compressor polytropic efficiency in percent. Outlet Temperature: Compressor outlet temperature. Efficiency is calculated. Single Adiabatic Efficiency Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to adiabatic efficiency in the Compressor Efficiency Curve window. Single Polytropic Efficiency Curve: Click Enter Curve… to supply a curve relating volumetric feed rate to polytropic efficiency in the Compressor Efficiency Curve window. Multiple Adiabatic Efficiency Curve: Click Enter Curve… to supply multiple curves at designated Compressor inlet or outlet pressures, which relate volumetric feed rate to adiabatic efficiency in the Compressor Multiple Efficiency Curves window. Multiple Polytropic Efficiency Curve: Click Enter Curve… to supply multiple curves at designated Compressor inlet or outlet pressures, which relate volumetric feed rate to polytropic efficiency in the Compressor Multiple Efficiency Curves window. Selection of an efficiency or temperature specification is optional, and if none is selected a default value of 100 percent adiabatic efficiency is used. Note that this corresponds to a perfect isentropic compression.


April 2014

RPM Adjustment of Compressor Curves Curves for head, work, and efficiency are usually based on a specific compressor speed. Therefore, they should be adjusted when the compressor is operated at a different speed. PRO/II performs adjustments for these curves when values are supplied for the Reference RPM (curve basis) and the Operating RPM. Adjustments are based on the fan laws and are as follows:

[

]2.0

[

]3.0

Head = Headref RPM / RPMreference

Work = Work ref RPM / RPMreference

[

Efficiency = Efficiency ref RPM / RPMreference

]

Aftercooler Option An aftercooler may be added via the Aftercooler… icon on the Compressor main data entry window and supplying the cooler outlet temperature and pressure drop in the Compressor Aftercooler window.

Outlet Temperature Estimate An estimate for the outlet temperature for the compressor may optionally be supplied in the Compressor main data entry window to speed convergence. Note that this is not the same as the Outlet Temperature specification.

Calculation Method Select the method to calculate the Compressor head by clicking Calculation Method… on the Compressor main data entry window. This displays the Compressor Calculation Mode window. The method may be chosen with the radio buttons provided, with choices as follows: GPSA Engineering Data Book: The GPSA Data Book equation is used to compute head. ASME Power Test Code 10: The ASME Power Test Code 10 equation is used to compute head. This method, the default, is the most rigorous. The compression ratio above which the head equation is used to compute the isentropic/ polytropic coefficient may also be supplied in this window. This entry only applies to the GPSA method, with a default value of 1.15 supplied. Below this compression ratio, the GPSA “temperature equation” is used to compute the isentropic/polytropic coefficients.

Chapter 9


Relative Convergence Tolerance for Work Specifications For compressors with Work specifications, a relative convergence tolerance may optionally be supplied in the Compressor main data entry window. A default value of 0.001 is used when no value is supplied.

Maximum Outlet Pressure For compressors with Work specifications, a maximum outlet pressure may optionally be supplied in the Compressor main data window. The outlet pressure will be reset to this value when the supplied work results in a pressure exceeding this value.

Thermodynamic System The thermodynamic system of methods to be used for compressor calculations may be selected by choosing a method from the Thermodynamic Systems dropdown list box on the Compressor main data entry window.

Controller

General Information The Controller simulates the action of a feedback process controlled by adjusting an upstream flowsheet parameter to achieve a specified result for a process stream or unit operation. A controller must have one Specification and one VARY, where the SPEC may be a stream flow rate or property, a unit operating condition, or a Calculator result. The control variable (VARY) must be a stream or unit operation flowsheet parameter that is otherwise at a fixed value in the flowsheet.

Specification The Specification is supplied via the appropriate underlined hypertext in the Specification field of the Feedback Controller main data entry window (accessed by double-clicking on the Controller flowsheet icon). By clicking the hypertext string Parameter, the Parameter window appears in which you can select the unit parameter or stream parameter to use as the SPEC. The SPEC may be a single parameter or a mathematical expression that relates two flowsheet parameters. You may next enter the value and the tolerance for the SPEC by clicking the appropriate linked text. See the SPEC/VARY/DEFINE section of this chapter for further details on the generalized SPEC form used in PRO/II.


April 2014

Variable The control variable (VARY) is selected by clicking the linked text string Parameter in the Variable field of the Feedback Controller window. The Parameter window is used to designate the stream or unit parameter to use for the VARY in a manner analogous to that used in selecting the SPEC above. The SPEC/VARY/DEFINE section of this chapter gives more information on the VARY concept. You will also find tables of the flowsheet variables that may be used for SPEC’s and VARY’s in controller units.

Limits and Step Sizes Limits and step sizes for the control variable may be supplied by clicking Limits and Step Sizes… on the Feedback Controller window. A maximum value, minimum value, and/or maximum change in the control variable may be entered in the Limits and Step Sizes window. Optionally, you may supply a value for the control variable for the second iteration by selecting the appropriate radio button to replace the default change of 2.0 percent of the initial control variable value. You may specify a different percent or value for the second iteration.

Parameters Several parameters regarding the operation of the Controller may be supplied on this section of the Feedback Controller window. You may change the maximum number of iterations from the default value of 10. Use the radio buttons may to select the action taken when the control variable exceeds the prescribed limits: •

The value is set to the limit as a solution and flowsheet calculations continue (the default), or

•

Flowsheet calculations are halted.

Print Results for Controller Iterations The default setting prints a summary for each iteration of the controller. To eliminate this printout, deselect the check box on the Feedback Controller window.

Next Unit Calculated after Control Variable is Updated Ordinarily, this is the first unit operation in the calculation sequence that is affected by the control variable and is determined automatically (“calculated”) by PRO/II. You may specify a different return unit by using the drop-down list box on the Feedback Controller window.

Non-convergence of Controllers The controller uses a Newton-Raphson technique to search for the value of the control variable that meets the specified flowsheet parameter result. Therefore, it

Chapter 9


is important that there be a continuous and monotonic relationship between the control variable and the specification. Control functions with discontinuities or localized maxima and minima may fail to converge or converge to an undesired result. For some cases, the limits and step sizes entries may keep the control function within a range of feasible solutions.

Controllers and Recycle Loops Controllers always create a recycle loop in the flowsheet, from the downstream unit at which the specification is evaluated to the first upstream unit affected by the control variable. When a controller is located within a recycle loop, PRO/II normally solves the controller as part of the loop. This means the controller and the recycle solve simultaneously. To reach convergence of the controller in each iteration of the loop, changes must be made to the calculation order. This typically is accomplished by re-ordering the controller to execute after the last downstream unit that is referenced by the controller. Tolerances are another area of attention. To ensure convergence, It is important for the tolerance of the controller to be tighter than the tolerance of the encompassing recycle loop. This page intentionally is left blank.

Counter Current Decanter

General Information The Counter Current Decanter is used to recover one or more liquid phase components from slurry, by countercurrent decantation with a solvent. The Counter Current Decanter can be used either as a clarifier or thickener, depending on the application.

Feeds and Products There can be multiple Slurry Feeds and Wash Feeds but there should be only two products. At least one Slurry Feed stream must be given which must contain both liquid and solid phases. Wash streams are mandatory only for the Design


April 2014

problem. The Overflow product contains primarily liquid with a little entrained solids whereas the Underflow product stream contains primarily solids with some liquid.

Calculation Mode Counter Current Decanter can be simulated in the Design mode or the Rating mode. i. Design Mode In Design problem, the number of stages is selected to achieve a given liquid component recovery in either the Overflow or the Underflow product. For Design problem, at least one WASH feed is a must. ii. Rating Mode In Rating Mode, the number of stages is a mandatory input. Hence, the number of stages will be fixed and the solids content in the product streams is calculated.

Operating Conditions Pressure Specification and Separation Factors constitute the operating conditions for counter current decanter. The separation factors used in calculation are Volumetric Flow rate and Mass Concentration. These are expressed as the ratio of the value in overflow product to that in the underflow product.

Crystallizer

General Information The Crystallizer unit operation simulates crystallization processes for the manufacture of organics, inorganics, fertilizers, biochemicals and polymers. The crystallizer transforms a supersaturated solution into a mixed solid/liquid crystal slurry. The crystallizer is modeled as a Mixed Suspension Mixed Product Removal (MSMPR) crystallizer or Continuous Stirred Tank Crystallizer (CSTC). These models assume ideal mixing in the unit and that the product conditions are the same as the bulk conditions. The model also assumes that breakage or agglomeration of solid particles is negligible. A feed heat exchanger may be included in the model with recirculation if required.

Chapter 9


The crystallization process depends on phase equilibria as well as kinetic or nonequilibrium considerations. Solid-liquid equilibrium is defined in terms of solubility, which is calculated from either the Van't Hoff equation or user-supplied solubility data. You must select Design or Rating calculations in the Crystallizer Calculation Mode window. In design mode, a specification is required and the volume is calculated. In the rating mode, the vessel volume is defined. The formation rate relationships are expressed as power law expressions in the Crystallizer Growth and Nucleation Rates window. These relationships are similar to equations for power law kinetics used for chemical reactions. Full details of the calculation method can be found in the PRO/II Reference Manual.

Feeds and Products The Crystallizer can have any number of feed streams. The inlet pressure is taken to be the lowest pressure of all the feed streams. Both an overhead and bottoms product must be specified in the Crystallizer Products window. The bottoms product contains the crystals in the solid/liquid slurry. The overhead contains any vapor generated in the unit.

Unit Specification A Crystallizer unit operation is specified by filling in the data variables for Solute and Solvent, Crystal Shape Factor, Calculation Mode, Design Specification (in Design Mode) and Growth and Nucleation Rates. Access the appropriate data entry windows from the Crystallizer main data entry window. Access the main Crystallizer Data Window by double-clicking the Crystallizer unit icon.

Crystal Shape Factor The shape factor defaults to 1.0 which indicates cubic crystals. A value of p/6 indicates spherical crystals.

Solute and Solvent Select the solute and solvent components. The solute must be defined as a liquid-solid component. If there are no liquid-solid components available in the simulation, a warning message is displayed prior to opening the Crystallizer main data entry window. To specify a component as liquid-solid, select Input/Component Selection/ Component Phases.

Calculation Mode Click Calculation Mode… to specify the Design or Rating calculation mode. In Design mode, a specification is required and the vessel volume is calculated. Specification options are:


April 2014

Crystal Production Rate: Enter the production rate of the crystals in weight units. Fraction of Solute Crystallized: Enter the fraction of the total solute in the combined feeds that is to be crystallized. Magma Density in the Bottom Product: Enter the density of the bottom product as weight of crystals per unit volume of slurry. Supersaturation Ratio: Enter the supersaturation ratio which is defined as: (Xexit - Xsat)/ Xsat where: Xexit is the liquid phase mole fraction of the solute in the bottom product, and Xsat is the saturation mole fraction of the solute in the bottom product. In Rating mode, the vessel volume is defined.

Growth and Nucleation Rates Click Growth and Nucleation Rates… to specify Growth and Nucleation Rates. Crystal Growth Rate: You must supply the Rate Constant for the rate equation in ft/sec or m/sec. Growth rates are typically in the range -7 -8 2.0x10 to 2.0x10 m/sec. By default, the rate is directly proportional to the Supersaturation Ratio. You may change this by overriding the default Exponential Factor. Factors are usually in the range 0.0 to 2.5. Crystal Nucleation Rate: The Nucleation Rate is the number of crystals nucleated per unit time, per unit liquid volume. You must supply the Rate Constant for nucleation and specify its dimensional units. By default, the rate is directly proportional to the Supersaturation Ratio. You may change this by overriding the default Exponential Factors. Typical values for the Supersaturation Ratio Factor are in the range 0.5 to 2.5 for secondary nucleation and up to 10 for primary nucleation. If an exponent is specified for the Impeller Speed, you may need to change the default value of 100 RPM.

Operating Conditions Click Operating Conditions… to specify Crystallizer Operating Conditions. By default, the crystallizer operates at the combined feed temperature and pressure with no recirculation. Pressure Specification: The pressure may be specified as a drop below the combined feed pressure or you may specify the pressure value directly.

Chapter 9


Second Specification: If an option other than At Merged Feed Temperature is selected, the unit is assumed to include a feed heat exchanger. You may specify either the crystallizer operating Temperature or the Duty of the exchanger. Recirculation Flow rate: Some of the bottom product may be remixed with the feed and passed through the feed exchanger. To specify this option, you must either specify the recirculation Volumetric Rate or the Temperature Change across the exchanger. A negative change denotes a temperature drop. Alternatively, instead of entering a numeric value for the parameters in this window, they may be referenced using the DEFINE system relative to any available unit operation or stream parameter calculated elsewhere in the simulation. See the table of Crystallizer Parameters available for CrossReferencing in the online help for more details.

Print Options Click Print Options… to access the Crystallizer Print Options window. Check the Include Crystal Size Distribution box to request additional output, including tables of fractions and population densities for the feed and product streams as functions of the crystal size distribution.

Cyclone

General Information The Cyclone unit operation models the separation of particulate solids from a solid and gas stream. The particulate collection efficiency is determined by the solids loading, component characteristics, particle size distribution, stream flow rate, and cyclone geometry. The Cyclone unit operation will calculate the collection efficiency for every particle size range of each solid component as well as the pressure drop through the unit. The Cyclone is assumed to operate isothermally and mechanisms such as agglomeration and crumbling are discounted.

Feeds and Products A Cyclone may have up to ten feed streams. Unless otherwise specified, the inlet pressure will be taken as that of the feed stream with the lowest pressure. The feed streams may not contain a liquid phase, and there must be two product streams. The overhead stream will contain all the gas that comes in as well as any uncollected solids. The bottom stream will contain only the collected solids.


April 2014

All solid components that enter a cyclone must have a particle size distribution. This distribution may be set by another unit or defined by the user.

Unit Specification A cyclone unit operation is specified by filling in the appropriate real and integer data variables for operating mode, geometry, pressure drop calculations, efficiency calculations, and multiple cyclone configuration in the Gas/Solid Cyclone main data entry window that is accessed by double-clicking the Cyclone unit icon on the PFD.

Rating Mode If you select Rating Mode, you must supply the diameter of the cyclone. The other dimensions of the cyclone will be generated from the diameter. If you select User Defined Geometry, you must also enter all of the geometric ratios as described below. In Rating Mode, PRO/II will calculate: pressure drop, total efficiency, component efficiencies, grade efficiencies and weight percent solids in the overhead stream.

Design Mode If you select Design Mode, you need not provide the cyclone diameter. Again, if you select User Defined Geometry, you must enter all of the geometric ratios as described below. In addition, you must specify a target for total solids collection (see entry for RPARM(13) below). You may also wish to override the default maximum pressure drop of 10 inches of water by entering a value in whatever input pressure units you prefer (see entry for RPARM(16) below). In addition to the normal Rating Mode output, Design Mode will calculate the number and size of identical cyclones that are necessary to meet the specification. There may be many cyclone systems that meet the specification. In all cases, Design Mode will return the system requiring the fewest cyclones.

Multiple Cyclones The Cyclone can model a system of identical cyclones that are arranged either in parallel or in series. In the case of parallel cyclones, the feed streams are split evenly among the cyclones. The overhead products from all cyclones merge into one overhead and the bottoms products from all cyclones merge into one bottom stream. In the case of series cyclones, the overhead from the first cyclone is the feed to the second and so on. The overhead product is the overhead product from the final cyclone while the bottom product is the combined bottom product from all the cyclones in the system. Both product streams are at the outlet pressure of the final cyclone in the system. It is not possible to specify recycle streams inside the unit or to reference intermediate stage data from the flowsheet. For example, if you wish to set a specification on the second cyclone in a three-cyclone series or set a recycle from the second cyclone to the first

Chapter 9


cyclone, you should model the system as three separate units. Note that while increasing the number of identical cyclones will increase efficiency and pressure drop in a series system, it will decrease the efficiency and pressure drop in a parallel system.

Integer Data for Unit Calculation Mode (IPARM(1)) This input is optional. Options are: 1. Rating (default) 2. Design Efficiency Model (IPARM(2)) This input is optional. Options for Rating and Design mode are: 1. Koch & Licht 2. API (default) 3. Lapple The Lapple model is based on a ratio of particle diameter to cut diameter (the diameter of the particles which are collected with 50% efficiency). The API method is based on a ratio of particle diameter to critical diameter (the diameter of particles which would be collected at 100%). The Koch & Licht method is not based on a particle size ratio. Pressure Model (IPARM(3)) This input is optional. Options for both Rating and Design mode are: 1. Koch & Licht (default) 2. API If the cyclone is inside another vessel, the API method allows values for the Inlet Width Ratio and the Superficial Gas Velocity (described later in the section titled Real Data for Unit) to be specified. Cyclone Geometry (IPARM(4)) This input is optional. Options for both Rating and Design mode are: 1. Stairmand (default) 2. High efficiency Swift 3. Lapple 4. General purpose Swift 5. Peterson & Whitby 6. User-defined geometry


April 2014

If the user-defined geometry is used, values must be specified for the inlet height ratio, inlet width ratio, cyclone dust outlet diameter ratio, cyclone gas outlet diameter ratio, gas outlet tube length ratio, height of cylindrical section ratio, and total cyclone height ratio as appropriate for the calculation method used as shown. Inlet Vane Flag (IPARM(5)) This input is optional. Options for both Rating and Design mode are: 1. No (default) 2. Yes Shape of Gas Inlet Flag (IPARM(6)) This input is optional. Options for both Rating and Design mode are: 1. Tangential (default) 2. Scroll or volute 3. Axial Cyclone is inside Vessel Flag (IPARM(7)) This input is optional. Options for both Rating and Design mode are: 1. No (default) 2. Yes For a value of 2, the Inlet Width Ratio and the Superficial Gas Velocity must be specified. Dipleg Size is calculated if the value of 2 is entered. Efficiency Adjustment Due to Loading Flag (IPARM(8)) This input is optional. Options for both Rating and Design mode are: 1. Adjust (default) 2. Do not Adjust Automatically Switch Pressure Drop Model (IPARM(9)) This input is optional. Options for both Rating and Design mode are: 1. Do not Switch (default) 2. Switch This entry allows changes to be made automatically in the pressure drop model between the Koch & Licht and API methods based on solids loading. Configuration of Multiple Cyclones Flag (IPARM(10)) This input is optional. Options for both Rating and Design mode are: 1. Parallel (default)

Chapter 9


2. Series Number of Identical Cyclones (Series or Parallel) (IPARM(11)): This input is optional and is used only in Rating Mode. The default value is 1 cyclone. Number of Particle Size to be Specified (IPARM(12)) This input is optional and is for Rating Mode only. This and the following entry can be used together to specify the component and PSD size range whose weight fraction in the overhead will be output to RPARM(64). This latter value can be accessed by a Controller, MVC or Optimizer. For example, if a solid with PSD data: 10, 20, 30, 40 (in default input units) is required to have a weight fraction of 0.20 in size range 20 to 30, the value for this entry would be 2 (the second size range) and the value for a DEFINE statement would be 0.20. The default value is 1 (the first size range). Number of the Component to be Specified (IPARM(13)) This input is optional and is for Rating Mode only. This optional input is the number of the component with particle size distribution data to be used in the design. The default is the first solid component with a PSD that the design mode may evaluate. Maximum Number of Cyclones (IPARM(14)) This input is optional and is for Design Mode only. The value indicates the number of cyclones in parallel or series as appropriate based on the value specified above for the Configuration of Multiple Cyclones Flag. The default is 20 for parallel and 3 for series.

Real Data for Unit The cyclone geometry is input as the ratio of length divided by overall cyclone body diameter, so that an inlet height of 0.1 meters on a cyclone of diameter 0.2 meters would have an inlet height ratio of 0.1/0.2 = 0.5. Diameter of Cyclone Cylinder (RPARM(1)) This input is required and is for Rating Mode only. Inlet Height Ratio (RPARM(2)) This Rating/Design Mode entry is optional. Inlet Width Ratio (RPARM(3)) This Rating/Design Mode entry is optional. Cyclone Dust Outlet Diameter Ratio (RPARM(4)) This Rating/Design Mode entry is optional. Cyclone Gas Outlet Diameter Ratio (RPARM(5)) This Rating/Design Mode entry is optional. Gas Outlet Tube Length Ratio (RPARM(6)) This Rating/Design Mode entry is optional.


April 2014

Height of Cylindrical Section Ratio (RPARM(7)) This Rating/Design Mode entry is optional. Total Cyclone Height Ratio (RPARM(8)) This Rating/Design Mode entry is optional. Diameter of Vessel Housing (RPARM(9)) This Rating/Design Mode entry is optional. Superficial Gas Velocity (RPARM(10)) This Rating/Design Mode entry is optional. Pressure Drop to Inlet (RPARM(11)) This Rating/Design Mode entry is optional. This value is the pressure drop between the feed stream and the inlet to the cyclone. The default is 0.0. Absolute pressure at cyclone inlet (RPARM(12)) This Rating/Design Mode entry is optional. For use if cyclone inlet pressure differs from feed stream pressure. The default is the lowest feed stream pressure. Goal Efficiency for Design Mode (wt%) (RPARM(13)) This Design Mode entry is required. Minimum Cyclone Diameter (RPARM(14)) This Design Mode entry is optional. The default is 0.1 m. Maximum Cyclone Diameter (RPARM(15)) This Design Mode entry is optional. The default is 0.5 m. Maximum Pressure Drop (RPARM(16)) This Design Mode entry is optional. This value is the maximum pressure drop across cyclones in a unit The default is 2.488 kPa. Tolerance for Cyclone Body Diameter (RPARM(17)) This Design Mode entry is optional. The default is 0.001.

Real Number Output from Cyclone The output values calculated by the Cyclone model are stored in the indicated locations in the RPARM() array and can be accessed by a Controller, MVC or Optimizer. All RPARM() outputs are produced in both Rating and Design modes. Overall Efficiency (wt%) (RPARM(51)) In Design mode, this is an input value included in the output report for the cyclone unit. Diameter Of Cyclone Cylinder (RPARM(52)) In Rating mode, this is an input value included in the output report for the Cyclone model. Pressure Drop (RPARM(53)) This is adjusted for loading by the user. Total Solids In Overhead (RPARM(54)) This is the weight % of the total overhead stream.

Chapter 9


Inlet Height Dimension (RPARM(55)) Inlet Width Dimension (RPARM(56)) Cyclone Dust Outlet Diameter Dimension (RPARM(57)) Cyclone Gas Outlet Diameter Dimension (RPARM(58)) Gas Outlet Tube Length Dimension (RPARM(59)) Height of Cylindrical Section Dimension (RPARM(60)) Total Cyclone Height Dimension (RPARM(61)) Dipleg diameter (RPARM(62)) This requires that the cyclone be located above a fluidized bed, i.e., the cyclone must be located inside a vessel. This value is output in the cyclone output report only if applicable. PSD weight fraction in the overhead RPARM(64) This value is the particle size distribution weight fraction in the overhead of the size and component specified. See entries for IPARM(12) and IPARM(13) above. This is the ratio of weight in the specified size range divided by the weight of the component in the overhead. This value is output in the cyclone output report only if applicable.

Rotary Drum Filter

General Information The Rotary Drum Filter unit is used to decrease the liquid content of a stream containing solids. The model assumes a rotating, horizontal drum partially submerged in a trough of slurry mixture, which is to be filtered.

Feeds and Products There can be multiple Feed Streams but only two products for Rotary Drum Filter. The Filtrate product consists of the liquid components removed from the feed(s) and contains no solids. The Cake stream is a mixed phase stream containing predominantly solids with some liquids.

Unit Specification A Rotary Drum Filter unit operation is specified by filling in the appropriate real and/or integer data variables in the tabs named as: Calculation mode, Operating Conditions and Cake Properties in the main data entry window. It is accessed by


April 2014

double-clicking the Rotary Drum Filter unit icon on the PFD. The variables associated with each tab are discussed below.

Calculation Mode In calculation mode Tab, one will see that the Rotary Drum Filter can be operated in either of the two modes: i. Rating Mode If one selects the Rating Mode, then Diameter and Width of the Rotary Drum Filter must be supplied. The Maximum Pressure Drop across the Rotary Drum Filter and Width to Diameter Ratio will be calculated. ii. Design Mode If one selects the Design Mode, one must provide the Maximum Pressure Drop across the Rotary Drum Filter diameter whereas Width to Diameter Ratio is optional. This will lead to the calculation of Diameter and Width of Rotary Drum Filter.

Operating conditions Value for Rotational speed of the drum (in RPM’s) is a mandatory user input, but one has a choice to specify either the angle of filtration or the percentage of drum submerged. The default values for angle of filtration and percentage of drum submerged are available.

Cake properties Porosity, Percentage of solids in the cake, Average Sphericity, Cake Resistance at existing pressure drop and Cake Compressibility have default values and hence are optional fields. User can either specify the percentage of solids in the cake or ask PRO/II to calculate it. In the latter case, Average Particle Diameter has to be made available through one of the following possible ways: (i) Particle Size Distribution (PSD) should be given so that PRO/II can calculate Average Particle Diameter and use it in further calculation sequence. (ii) It can be given directly as a user input in the Float field provided. PS: Though the Float field is shown as optional, there is no default value for Average Particle Diameter. In the similar way, user can either specify the Filtration Resistance or ask PRO/II to calculate it. If user wants PRO/II to calculate the Filtration Resistance, then the Specific Resistance is a mandatory user input.

Chapter 9


Solids Dryer

General Information The Solids Dryer is used to decrease the liquid content of a stream containing solids. Generally, the liquid being removed is water. The Solids Dryer may be operated at a fixed temperature and pressure or at a fixed heat duty requirement. Alternatively, the pressure or temperature may be fixed and a design specification placed on one of the product streams, generally, the dried solid stream.

Calculation Method The Solids Dryer provides the option of specifying two specifications to satisfy the degrees of freedom. Two types of specifications are available for this unit operation; they are Operation Specification and Design Specification. Flash calculations are used to meet the provided specifications.

Feeds and Product Streams The Solids Dryer unit can have any number of feed streams. The Solids Dryer unit requires two product streams. Both an overhead and bottoms product streams must be specified.

First Specification Select one of the following parameters: Pressure Drop: The decrease in outlet pressure over the lowest feed stream pressure. Negative values indicate a pressure rise. Pressure: The pressure in the Solids Dryer Temperature: The temperature in the Solids Dryer.

Second Specification Select one of the Unit Specification or supply product specification.

Unit Specification Choices If Pressure/Pressure Drop is selected in the first specification Temperature and Duty are available for selection in the unit specification list box. If Temperature is selected in the first specification Pressure, Pressure Drop and Duty are available for selection in the unit specification list box.


April 2014

Temperature Estimate: Optionally, supply an estimate for the temperature value, which will be taken as the starting point of the iterative calculations to determine the actual temperature. Pressure Estimate: Optionally, supply an estimate for the pressure value, which will be taken as the starting point of the iterative calculations to determine the actual pressure.

Product Specification Choices 

Rate



Moisture Content



PPM



Fraction



Vapor Fraction

Rate: The flow rate of either the OVHD or BTMS stream on a weight (WT) basis or a molar (M) basis. The default is weight. Molar may only be used if all solids have their molecular weights defined. If COMPONENT is also used, then rate refers to the flow rate of a component or group of components. When RATE is used with the BTMS keyword, the rate may refer either to the total BTMS rate (PHASE=T and default) or to the liquid portion of the BTMS rate (PHASE=L). Fraction: The fraction of a particular component or group of components in the OVHD or BTMS stream on a weight (WT) basis or a molar (M) basis. The default is weight. Molar may be used only if all solids have their molecular weights defined. The COMPONENT entry is also required. PHASE=T is not allowed with this specification. PHASE=L must be entered Moisture: The moisture content of the BTMS stream on a weight (WT) basis or a molar (M) basis. The default is weight. Molar may only be used if all solids have their molecular weights defined. Moisture Content is defined as the ratio of mass or moles of water to mass or moles of total solids. PPM: The parts per million of a particular component or group of components in the OVHD or BTMS stream on a weight (WT) basis or a molar (M) basis. The default is weight. Molar may be used only if all solids have their molecular weights defined. The COMPONENT entry is also required. PHASE=T is not allowed with this specification. PHASE=L must be entered Vapor Fraction: The fraction of the feed vaporized on a weight (WT) basis or a molar (M) basis. The default is weight. Molar may only be used if all solids have their molecular weights defined. The fraction may refer either to the total feed rate (PHASE=T and default) or to the liquid portion of the feed (PHASE=L). The BTMS keyword is not allowed with VFRAC.

Chapter 9


Melter/Freezer

General Information The MELTER/FREEZER unit operation model provides the capability to melt a solid to transform it into the liquid phase and freeze a liquid to transform it into the solid phase. The component phase type must be VLS or LS for each component to be considered for this operation.

Feeds and Product Streams The Melter/Freezer unit can have any number of feed streams. The unit requires minimum one product stream and can be connected to maximum of four product streams. Generally these product streams are corresponding to different phases.

Calculation Method The calculations are based on the melting temperature of the component. However, the liquid-solid equilibrium effects are not considered. The unit is capable of operating in two modes. These include performing calculations when the user provides the specification as Melting/Freezing fraction and the other by performing calculations based on Normal Melting Point (NMP). If the optional MELFRAC or FREFRAC keywords are not supplied on the OPERATION statement, the melting temperature is used to determine appropriate phase transformations. If the MELFRAC and FREFRAC keywords are used, the unit will ignore the melting temperature for those components with MELFRAC/FREFRAC specified. The specified fractions then determine the extent of phase transformation. The products are flashed at outlet pressure and temperature to determine vapor-liquid distribution. The duty is reported by taking the initial and final thermodynamic states into account (which includes the heat of fusion for transformed solid components).

Unit Specifications User can specify the thermal condition and melt/freeze condition as specifications. None of these specifications are compulsory. Pressure drop of zero and temperature drop of zero are being considered as default specification values.

Thermal Condition First Specification


April 2014

Select one of the following parameters: Pressure Drop: The decrease in outlet pressure over the lowest feed stream pressure. Negative values indicate a pressure rise. Pressure: The pressure in the Melter/Freezer Unit.

Second Specification Select one of the following parameters: Temperature Drop: The decrease in outlet temperature over the feed stream temperature. Negative values indicate a temperature rise. Temperature: The temperature in the Melter/Freezer Unit. Temperature Estimate: Temperature related specification and Temperature Estimate are mutually exclusive. One can be provided. Temperature Estimate can be provided by selecting the radio button associated with it.

Melt/Freeze Condition After selecting the Melt/Freeze Fraction radio button, the grid associated with the radio button is enabled and the focus will be changed to Starting Component list box. User can provide the Melt/Freeze fraction by selecting the starting component, ending component, melt/freeze type and the value of the fraction. Melt/Freeze fraction can be provided for range of components and can also be defined using PRO/II Define system. In case of defining fraction, both the starting and ending component must be same. However, define feature is not allowed for multiple components. The other parameters that can be defined with PRO/II define system include Temperature, Pressure, Pressure Drop, Temperature Drop and Melt/Freeze fraction.

Product Phases Button When there are multiple product streams leaving the Melter/Freezer unit, user will be able to configure the Product Phase options. User must specify the product phase for each stream using the Product Phases window, which is displayed when this button is pushed.

Depressuring Unit

Chapter 9


General Information The Depressuring Unit simulates the time-pressure-temperature relationships that occur when a vessel is depressured through a relief or control valve. Several different valve models, vessel configurations and models for heat flow into the unit are available. An optional external makeup stream may also be specified. The initial phase of the vessel contents may be either a vapor or a vapor-liquid mixture.

Calculation Options Calculation options include procedures from API Standard 2000, API Recommended Practice 520, and other industry standards.

Initial Relief Conditions The initial relief conditions can be based on either a specified initial time or a specified initial pressure by selecting the appropriate radio button. The default selection is to start the depressuring calculations at the beginning of the simulation (time zero.) Note: This option is only available if the heat input model type “Fire Relief Model” is selected.

Final Depressuring Conditions To set the final depressuring conditions, values may be entered for either or both final Vessel Pressure and Elapsed Time. The elapsed time can be measured from Time Zero or from the Start of Relief by choosing the desired toggle text. If both final Vessel Pressure and Elapsed Time are selected, the depressuring calculations will stop when the first criterion is satisfied.

Time Step Size Calculation Options User-supplied values for the relative volume tolerance per time step, the maximum number of time steps, and the time step size can be entered on the Calculation Options window. This window is brought up by clicking Calculation Options… on the Depressuring Unit main data entry window. The default value for the Volume Tolerance per Time Step is 0.0001. The default value for the Maximum Number of Time Steps allowed in the depressuring simulation is 100. The default value for the Time Step size is calculated using default values for the sizing parameters. User-supplied values for the parameters used in this calculation may be entered via the appropriate hypertext string. The step size basis is selected from a pop-up list, which includes a. total fluid quantity in increments of the amount* (a constant)


April 2014

b. vapor quantity in increments of the amount* (a constant), or c.

the smaller of (1) or (2).

The default selection for time step size basis is (a). Choosing either (a) or (a) allows entering user-supplied values for the constants in the pop-up float field. For the time step size basis of (1), the default value of the constant is 0.04. For (2), the default value of the constant is 0.50.

Specification of Isentropic Efficiency Either the default isentropic efficiency or a user-supplied value may be used in the blowdown calculations by selecting the appropriate radio button on the Depressuring Unit - Calculation Options window. For all heat flow models except for Rigorous Blowdown or Semi-rigorous Blowdown, the default value is 0.0. If Rigorous Blowdown or Semi-rigorous Blowdown is selected for the Heat Flow Model, the default isentropic efficiency is 1.0.

Action when Errors are Detected By default, the simulation will stop if pressure profile errors are detected. Clicking on the Stop hypertext on the Calculation Options window toggles the option to Continue and allows the simulation to continue even if pressure profile errors are detected.

Valve Data Data can be entered on the Depressuring Valve Data window to define the flow characteristics of the relief valve or control valve. This window is brought up by clicking Valve Data… on the Depressuring Unit main data entry window. A Valve Model must be selected from the four choices by choosing the appropriate radio button. The available valve models are Supersonic Flow, Subsonic Flow, Constant Flow, Orifice, and User Model. The default is Supersonic Flow. The equation for the selected model is displayed as an aid to entering the parameters in the valve equation. The units displayed for the equation are consistent with the default UOM for the problem and may not be changed. A Valve Constant (C) must be entered for all models except for the User Model. For the Supersonic Flow model, the valve constant is the only entry allowed. For the Subsonic Flow model, an optional back pressure may be entered along with the required the valve constant. For the Constant Flow model, the only allowable entry is the valve constant. For the User model, the control valve coefficient must be entered. The Valve Constant (C) can be provided either as a single value or as a profile through the policy grid. If you are using a profile, the Valve Constant is calculated, at the respective time steps, by using the liner profile.

Chapter 9


The default value for back pressure is 0.0 and the default value for critical flow factor is 1.0. You may enter different values if desired. Downstream Pipe Diameter is not a required field, but it is useful in finding the outlet conditions of the valve. If Diameter is not entered, the downstream pressure and temperature do not appear in the output report.

SOLID CO2/H2S/C6H6 Prediction By default, the simulation will not predict the formation of Solid CO2/H2S/C6H6. Selecting this option will predict solid CO2/H2S/C6H6 formation at all time steps. This option also prints and predicts the density of solids formed.

Vessel Data The Depressuring Vessel Data window is used to define the configuration of the depressuring unit. This window is accessible via the Vessel Data button on the Depressuring Unit main data entry window. One of the following must be selected by choosing the appropriate radio button. •

Sphere

•

Horizontal Cylinder

•

Vertical Cylinder

•

Unspecified Shape

If Sphere is the selected vessel geometry, a value for the diameter must be entered. If Horizontal Cylinder is the selected vessel geometry, the diameter and tangent-to-tangent length must be entered. For the Vertical Cylinder vessel geometry, the diameter and tangent-to-tangent height must be entered. For vessels of any of these defined geometries, entering a value for liquid height is optional. For vessels of the Unspecified Shape geometry, the vessel volume must be entered. Liquid Holdup is optional only if the geometry is Unspecified Shape. By default, the holdup liquid is saturated liquid of the combined feed composition at the initial conditions. The remaining vessel volume contains vapor in equilibrium with this liquid. The holdup may be on a mole, weight, or actual volume fraction basis with the default being the mole fraction basis. The Vessel Weight and the Vessel Specific Heat can be entered for any vessel geometry. Vessel Weight can be calculated by using Vessel Density and Vessel Wall Thickness. If Vessel Specific Heat is given, either Vessel Weight is required or Vessel Wall Thickness and Vessel Density are required. Vessel Density and Vessel Wall Thickness are applicable to spherical, horizontal, cylindrical, and vertical vessel geometries. These items are required only if “Blowdown” appears


April 2014

on the Heat Input window, otherwise they are optional. (See discussion on vessel Heat input options below.) The volume correction factor is an optional entry for the Sphere, Horizontal Cylinder, and Vertical Cylinder vessel geometries only. This entry is used to correct the vessel volume for pipes, fittings, and end plates and defaults to 1.00 if not supplied.

Heat Input Click Heat Input… on the Depressuring Unit main data entry window to open the Heat Input window. A heat input model may be selected from the drop-down list box, which includes the following options: •

User-defined

•

API 2000

•

API 2000 Method with Scaling

•

API RP 520 with Scaling

•

API RP 520

•

Isothermal

•

Rigorous Blowdown

•

Semi-rigorous Blowdown

•

Fire Relief.

User-Defined is the default as this supplies no heat input to the vessel. The difference between the Rigorous and Semi-rigorous Blowdown models is the physical property calculations. The selected heat transfer equation is displayed, along with the equation’s units of measure. Depending on the Heat Flow Model selected, from one to five of the coefficients may be supplied. For the UserDefined or Semi-rigorous or Rigorous Blowdown models, values for these coefficients default to 0.0. The User-Defined model allows up to six coefficients while the Blowdown model allows five coefficients. In these two models, each coefficient ‘Ci’ is used as a separate term. By omitting or providing zero as the value of coefficient effectively removes it from the equation (i.e. the contribution of the term is zero). Therefore, by selecting non-zero values for different combinations of coefficients, these two equations will support wider variety of equation forms. For example, the sixth coefficient in the User-Defined model allows a modelling called NORSOK correlation. For the Fire Relief Model only, the first two coefficients C1 and C2 are required.

Chapter 9


The Initial Wetted Area field is made unavailable when a value has been entered for Liquid Height on the Vessel Data window. Otherwise, a value for Initial Wetted Area must be entered for the API 2000, Scaled API 2000, RP 520, Scaled RP 520, and Fire Relief Models. The Area Scaling Factor is an optional entry for these same heat input models only when the Initial Wetted Area is input. It has a default value of 1.0. Calculate Dynamic Wetted Area is an additional input to Initial Wetted Area. It is used to calculate the Wetted Area dynamically for Liquid Holdup changes. The Heat Input Scaling Factor may be input for any heating model except the Semi-rigorous and Rigorous Blowdown and Isothermal models. It has a default value of 1.0. The Semi-rigorous and Rigorous Blowdown models provide the following radio button options for the heat transfer coefficient: Calculated Using Scaling Factor, Overall coefficient, or individual vapor and liquid phase heat transfer coefficients. The default is the Calculated Using Scaling Factor option with a default scaling factor of 1.0.

Makeup Stream One feed stream to the depressuring unit can be designated as a constant-rate makeup stream. Click Makeup… on the Depressuring Unit main data entry window to open the Makeup Stream window, where a makeup stream can be designated. Checking the box enables a drop-down list box which contains the names of all feed streams to the depressuring unit shown on the PFD. One stream may be selected as a makeup stream. The flow of this stream will always begin at time = 0, regardless of when the depressuring begins. By default, no makeup stream is included.

Print Results for Depressuring Unit The Print Options window allows the user to control the intermediate and final printed results for the Depressuring Unit. This window can be accessed through the Output/Report Format/Unit Operations menu option or from the Depressuring Unit main data entry window. The default for all stream printout is a molar basis; clicking on the toggle text allows the user to select weight basis. By default, component compositions are printed for all steps. The user may choose to print all steps, or only the initial, final, and relief conditions, by clicking the hypertext. The user may suppress all composition printout by deselecting the box. Intermediate printout is printed at each calculation step time by default. The user may select a different interval by clicking the default time step linked text, which brings up the Intermediate Print Interval Options window. The Intermediate Print


April 2014

Interval Options window provides the following radio button options for specifying the print frequency of intermediate results: Default Time Step, User-defined Time Step, and User-defined Pressure Interval. Simply select the appropriate radio button.

Products The vent gas product streams can be set either at the calculation time steps or at the specified time steps. If the total number of time steps is less than the total number of product streams, the total number of time steps is considered for associating the data generated by the depressuring unit with the product streams. Similarly, if the number of product streams is lesser than the total number of time steps, the number of product streams is considered. For example, if the number of time steps is 2 and the total number of product streams is 5. The data is associated only with the first two product streams, the rest 3 are not considered.

Thermodynamic System For problems where more than one thermodynamic method has been specified, a drop-down list box allows the selection of a thermodynamic method set to be used for the Depressuring Unit.

Dissolver

General Information The Dissolver unit operation models the dissolution of solids into liquid solutions. This mass transfer operation is widely used in the chemical industry in both organic as well as inorganic processes.

Feeds and Products The dissolver unit can have any number of feed streams. The inlet pressure is taken to be the lowest pressure of all the feed streams. Both an overhead and bottoms product must be specified. The default allocation may be modified in the Dissolver Products window. The bottoms product contains the liquid product along with any remaining crystals. The overhead contains any vapor generated in the unit.

Chapter 9


Calculation Method The dissolver transforms crystals in solution from the solid to the liquid phase. PRO/II models the most common type of dissolver which is the stirred tank dissolver. A feed heat exchanger may be included in the model if required. A Solid-liquid equilibrium method must be defined in terms of solubility, which is calculated from either the Van't Hoff equation or user-supplied solubility data. You must select Design or Rating calculations in the Dissolver Calculation Mode window. In Design mode, a specification is required and the volume is calculated for a given feed particle size distribution and operating conditions. In Rating mode, the vessel volume is defined and the exit particle size distribution is determined. The mass transfer coefficient may be specified in the Dissolver Dissolution Rate window. Alternatively, you may specify that the coefficient should be calculated from diffusivity data entered in the Thermodynamic Data. Full details of the calculation method can be found in the PRO/II Reference Manual.

Filtering Centrifuge

General Information The Filtering Centrifuge unit is used to decrease the liquid content of a stream containing solids. The most common types of filtering centrifuge are basket types. A slurry mixture to be filtered is fed to a rotating perforated basket lined with a cloth or mesh insert. This insert retains the solids as the liquid is forced through the basket by centrifugal force. The Filtering Centrifuge may be operated in design or rating mode. In design mode, a list of allowed bowl diameters (and optionally rotational speeds) is provided. One diameter and speed is selected from this list, which satisfies the required flow rate. In rating mode, the pressure drop is calculated for a given diameter and speed.

Feeds and Product Streams The Filtering Centrifuge unit can have any number of feed streams. The Filtering Centrifuge unit requires two product streams. Generally these product streams are corresponding to Cake and Filtrate.


April 2014

Calculation Method For rating applications, the basket diameter, and rotational speed in revolutions per minute and centrifuge type are specified. The centrifugal force is then computed using the following equation:

Where: gcent = Centrifugal force R= radius of centrifuge basket.

(Rotational Speed rad/sec) RPM = rotational speed of basket in revolutions/min gc = acceleration due to gravity The amount of solids remaining the basket is computed from:

Where: = mass of solids remaining in the basket = radius of inner surface of filter cake h = height of basket = solid density = average filter cake porosity The thickness of the filter cake is given by:

Chapter 9


The surface area of the filter basket and the log-mean and arithmetic mean area of the filter cake are given by:

Where: = log-mean surface area of filter cake. = arithmetic mean surface area of filter cake = surface area of filter basket The drainage of liquid through the filter cake of granular solids in a filtering centrifuge is a result of two forces; the gravitational force, and the centrifugal force in the basket, and is given by:

Where: K = permeability of filter cake = diameter of cake particle A, B are constants

The values of the constants A and B in equation (7) are a function of, the ratio of the cake sphericity to the cake porosity. A and B is given by: For

> 1.5,


April 2014

For

< 1.5,

The residual cake saturation, a result of small amounts of liquid held between the cake particles by surface tension forces, is a function of a dimensionless group known as the capillary number, Nc. The capillary number is given by:

Where: = liquid density = liquid surface tension The residual cake saturation, s0 is then calculated based on the value of the capillary number: For 0.002 < Nc < 0.03,

For Nc > 0.03,

For Nc < 0.002,

Chapter 9


The cake drain number and height are calculated from the cake permeability, centrifugal force, and the liquid density and surface tension:

The average cake saturation is then given by:

Where: = average filter cake saturation The corresponding moisture content of the filter cake, Xcake, is calculated using:

Finally, the actual rate of filtrate through the basket is given by:

Where: = rate of filtrate = total mass rate of feed to centrifuge


April 2014

= weight fraction of liquid in feed = weight fraction of solid in feed = total mass rate of inert components in feed For design calculations, an iterative method solution method is used, in combination with the equations given above, to calculate the filter diameter required to produce a specified filtrate flow.

Design Specifications Diameter and RPM List: For DESIGN case, enter a list of allowable diameters in course length units in the first column of design specifications grid. A corresponding list of rotational speeds may also be entered into the second column of the grid. The “best” diameter is selected such that the maximum filtrate throughput of the centrifuge is just larger than the actual filtrate flow rate.

Rating Specifications Diameter: Diameter of the bowl in course length dimensions Rpm: Rotational speed of the bowl. If Centrifuge TYPE is not selected, RPM is required. Centrifuge Type: PRO/II provides the support for five different kinds of centrifuges as indicated below. Default selection is “Centrifuge type “Not Specified” ”. Table 2 : Centrifuge Types Type

Description

WIDE

Wide angle. Half angle of basket cone angle of repose of solids.

DIFF

Differential scroll. Movement of solids from filter basket controlled by a screw.

AXIAL

Axial vibration. High frequency force applied to the axis of rotation.

TORSION

Torsional vibration. High frequency force applied around the drive shaft.

Chapter 9


OSCIL

Oscillating. A low frequency force is applied to a pivot supporting the drive shaft.

Operating Conditions The Liquid ratio, Cake ratio and Height ratio constitute the operating conditions for filtering Centrifuge. All the ratios have default values. The ratios are defined as: Liquid Ratio: The ratio of the radius of the liquid surface to the radius of the centrifuge. The default value is 0.738. Cake Ratio: The ratio of the radius of the filter cake surface to the radius of the centrifuge. The default value is 0.79. Height Ratio: The ratio of the height of the centrifuge to the radius of the centrifuge. The default value is 0.9545

Cake Properties Data for cake properties is provided using this group box. The user is expected to provide cake properties as determined from laboratory experiments or actual operating unit measurements. If this data is not available, the model calculates the cake properties based on default values. The percentage of solids in the cake can be provided directly or calculated using the sphericity of the particles and the particle diameter. The particle diameter can be specified directly or by the definition of a particle size distribution for the feed stream(s). If the feed stream contains the particle size distribution information, data entry for average particle diameter becomes optional. The cake properties include: Porosity: The porosity of the cake. It has the default value of 0.45. Filter Medium Resistance: The resistance of the filter cloth or screen to the filtrate. This has dimensions of reciprocal course-length. The default value is 0.2E+07/m or equivalent in other dimensional units. Specific Cake Resistance: The specific resistance of the cake. This has dimensions of course-length per weight. The default value is 0.2E+07 m/kg or the equivalent in other dimensional units. Percentage of Solids: The percentage of solids in the filter cake. The default is 50 percent. It is calculated using the defined value of sphericity and particle diameter.


April 2014

Sphericity: The sphericity of the particles in the cake. This entry is not required if percentage of solids is given. It is used in conjunction with average particle diameter to calculate percentage of solids. The default value is 0.75. Average Particle Diameter: The average particle diameter of the cake. If the particle size distribution is not defined for the feed stream, then average particle diameter may be provided. It is used in conjunction with sphericity to calculate percentage of solids. However, this property is not applicable if the percentage of solids is used. The dimensions are fine length.

Excel Unit

General Information The Excel unit operation allows using Microsoft Excel spreadsheet files to model general unit operations in the flowsheet. During calculation, PRO/II transfers feed stream information to the spreadsheet, invokes a user-defined macro, then reads the resulting product stream information back into PRO/II. An Excel file usually contains several worksheets of information. One of these worksheets is used to exchange data between PRO/II and Excel. This data transfer worksheet has a specific format which is described below in the section Data Transfer Sheet. All other sheets in the workbook are ignored by PRO/II and can be used for any other purpose. When PRO/II is installed, an "empty" Excel file (ExcelTemplate.xls) is installed which can be used as a starting point for developing custom spreadsheets. Note: ExcelTemplate.xls does not perform any calculations. A developer can copy and customize the spreadsheet by adding the required macros and/or spreadsheet formulas to calculate the output stream conditions based on the input feed streams and the unit operation data. After the spreadsheet has been customized, a user can add it to a PRO/II flowsheet using the Excel unit operation: 

After starting PRO/II, select File/New from the menu. The PFD Icon palette is displayed.



Scroll to the bottom of the PFD palette, click the Excel button, and click an empty area of the flowsheet to add a new Excel unit operation.



Connect the required feed and product streams.

Chapter 9




Double-click the Excel icon to display the tabbed dialog box (see next section Excel Configuration Dialog Box). This tabbed dialog box is used to specify the name of the Excel file, the name of the worksheet used as the data transfer area, and the name of the macro to invoke at calculation time.



After configuring is complete, click OK to exit the tabbed dialog.

After the flowsheet solves, PRO/II transfers feed stream information to the spreadsheet, invokes the user-defined macro, and then reads the resulting product stream information back into PRO/II. The default text report that PRO/II generates includes the values of the Excel unit operation data arrays.

Limitations The Excel unit operation has the following limitations: •

The Excel macro cannot make any direct function calls back into PRO/II. All communication with PRO/II is done through the data transfer sheet.

•

Use of the PRO/II COM Server functions to access data in the current flowsheet is not supported.

•

The Excel spreadsheet is not stored in the .prz simulation file.

Excel Configuration Dialog Box When the user double-clicks on the Excel unit icon, the following tabbed dialog box is displayed.


April 2014

Figure9-1: Excel Unit Tabbed Dialog Use the main Excel Data Entry Window to specify the configuration and general unit operation information. The window is organized into five tabs.

Spreadsheet Information: contains Excel configuration information. •

Display Excel during calculations: If checked, Excel is displayed when invoked by PRO/II. If unchecked, Excel executes in 'hidden' mode.

•

Save Excel file after calculations: If checked, the state of the Excel spreadsheet is saved after PRO/II calculations.

•

Spreadsheet name: Enter the name of the spreadsheet file. If no path is specified, then the Excel file must reside in the same directory as the PRO/II simulation file.

•

Worksheet name: Specify the name of the worksheet in the Excel file that is used as the transfer area. The default value is "Sheet1".

•

Macro name: Specify the name of the macro to invoke by PRO/II during calculations. The default value is "Macro1".

Integer data: This tab contains an integer data array similar to the "Integer Data" grid in the generic "User-added Unit Operation". This data is

Chapter 9


transferred to Excel during calculations; therefore, the values can be used to supply additional data to the Excel spreadsheet. A user can specify descriptions and values for this data. Parameter data: This tab contains a double-precision data array similar to the "Real Data" grid in the generic "User-added Unit Operation". This data is accessible via PRO/II's SPEC/VARY/DEFINE mechanism, which allows Excel spreadsheets to interact with controllers, MVC units, Optimizers, and the Case Study feature. This data is transferred to Excel during calculations; therefore, the values can be used to supply additional data to the Excel spreadsheet. A user can specify descriptions and values for this data. Double data: This tab contains a double-precision data array similar to the "Supplemental Data" grid in the generic "User-added Unit Operation". This data is transferred to Excel during calculations; therefore, the values can be used to supply additional data to the Excel spreadsheet. A user can specify descriptions and values for this data. Thermodynamics: This tab contains a drop-down list box that can be used to select the Thermodynamic set for the unit operation. Note: This tab contains two text boxes that allow specifying a unit description and the unit notes.

Data Transfer Sheet The worksheet used to transfer data between PRO/II and Excel has a specific format as described in the following table. The Column and Cell identifiers assume that the spreadsheet is configured to support five feed streams and five product streams. If the spreadsheet is modified to increase or decrease this number, then the actual cells for the rows highlighted with an asterisk (*) change accordingly. For example, increasing the number of feed streams to 6 changes the column corresponding to the first product stream from column H to column I. Column or Cell D2

*

Contents At calculation time, PRO/II fills this cell with the number of components in the simulation.


April 2014

Column or Cell

*

Contents

F2

Maximum number of feed streams supported by the spreadsheet. At calculation time, PRO/II reads this value to insure that the number of actual feed streams is less than or equal to the number of columns reserved in the spreadsheet. PRO/II does not change this value. This value must match the number of 'blue' columns used to store feed stream information. If a user customizes the spreadsheet to add one or more blue columns, then this number must be increased to match.

H2

Maximum number of product streams supported by the spreadsheet. At calculation time, PRO/II reads this value to insure that the number of actual product streams is less than or equal to the number of columns reserved in the spreadsheet. PRO/II does not change this value. This value must match the number of 'yellow' columns used to store product stream information. If a user customizes the spreadsheet to add one or more yellow columns, then this number must be increased to match.

J2

Number of rows (starting with row 5) reserved for bulk stream properties. At calculation time, PRO/II reads this number to determine in which row to begin writing stream compositions. PRO/II does not modify this value.

W4

*

Number of additional parameters to be included in the text report. At report time, PRO/II reads this value to determine how many additional data items in columns V and W will be written to the output report.

C5:G24

*

At calculation time, PRO/II fills this range of cells with feed stream information. The number of columns is defined by cell F2; the maximum number of rows is defined by J2.

C25:Gnn

*

At calculation time, PRO/II fills this range of cells with component rate information of the feed streams. The number of columns is defined by cell F2; the number of rows is defined by D2. The values are expressed in PRO/II internal units-of-measure.

H5:L24

*

At calculation time, the spreadsheet fills this range of cells with product stream information. The number of columns is defined by cell H2; the maximum number of rows is defined by J2.

Chapter 9


Column or Cell

*

Contents

H25:Lnn

*

At calculation time, the spreadsheet must fill this range of cells with component rate information of the product streams. The number of columns is defined by cell H2; the number of rows is defined by D2. The values should be expressed in PRO/II internal units-of-measure.

M, O

*

At calculation time, PRO/II will write values to columns M and O. Column M will contain the names of the unit operation Integer (INT) attributes as defined in the Unit Operation Data Definition (.ini) file; column O will contain the current values. After the spreadsheet macro is complete, the updated values in column O will be returned back to PRO/II.

P, R

*

During calculations, PRO/II writes values to these columns. Column P contains the names of the unit operation Parameter (PAR) attributes defined in the Unit Operation Data Definition (.ini) file. Column R contains their current values. After the spreadsheet macro finishes, updated values in column R are returned back to PRO/II. Values are transferred in the units-ofmeasure specified in the [UOM] section of the Data Definition file.

S, U

*

During calculations, PRO/II writes values to these columns. Column S contains the names of the double-precision (DBL) attributes as defined in the Unit Operation Data Definition (.ini) file. Column U contains their current values. After the spreadsheet macro ends, updated values in column U are returned back to PRO/II. Values are transferred in the units-ofmeasure specified in the [UOM] section of the Data Definition file

V

*

Contains the descriptions of the attributes that are included in the PRO/II default text report. PRO/II does not change these values. The number of descriptions and values included in the PRO/II report is specified by the number in cell W4.

W

*

Contains the values calculated by the spreadsheet macros and/or formulas. PRO/II does not change these values. When generating the default text report, PRO/II will include the descriptions from column V and values from column W in the text report. The number of descriptions and values included in the report is specified by the number in cell W4.


April 2014

Column or Cell

*

Contents

X, Y

*

Column X contains the list of unit-of-measure classes. Column Y contains the conversion factor between input and internal units of measure. Normally this value is not required because PRO/II writes all values to the spreadsheet in the same units-of-measure regardless of the units-of-measure selected in the input file. For details on the unit-of-measure classes, refer to the PRO/II UserAdded Subroutines User Guide.

* The actual column used for this data depends upon the declared number of feeds and products. Changing the number of feeds or products changes the column correspondingly. As delivered, the unit has 5 feeds and 5 products.

Additional Customization The Excel unit operation in PRO/II provides generic data attributes and GUI capability. It is possible to perform additional customization using the capabilities of the Modular User-Added Unit Operations. Specifically, the following items can be customized: •

Custom Data attributes names and full support for units-of-measure.

•

Custom tabbed dialog box.

•

Custom icon on the PFD palette.

To perform these modifications, refer to the PRO/II User-Added Subroutines User Guide.

Expander

General Information The Expander operation may be used to model any isentropic expansion such as an expander unit in a natural gas processing plant or a steam turbine, etc. Adiabatic expansion efficiency may be applied to the calculations. Rigorous calculations may be performed for both VLE and VLLE systems.

Chapter 9


Feeds and Products An expander operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. An expander may have one or more product streams. The product phase condition for operations with one product stream is automatically set by PRO/II. For expanders with two or more product streams, the product phases must be specified in the Expander Product Phases window which is accessed by clicking Product Phases… on the Expander main data entry window. Allowable product phases include: vapor, liquid, decanted water, heavy liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified.

Pressure and Work Specifications The outlet conditions for an expander may be selected with the radio buttons provided on the Expander main data entry window. A pressure or work specification is required for every expander. Options are as follows: •

Outlet pressure

•

Pressure ratio (absolute outlet pressure/absolute inlet pressure)

•

Pressure drop

•

Work

A relative tolerance in percent may also be defined for convergence of work specifications. If none is given, a default value of 0.001 percent is used.

Adiabatic Efficiency The isentropic work is adjusted by application of the adiabatic efficiency supplied in the Expander window. When not supplied, a default value of 100 percent is used (perfect isentropic expansion).

Minimum Outlet Pressure For expanders with work specifications, a minimum outlet pressure may optionally be defined in the Expander main data entry window. The work will be reset as needed so this minimum pressure is not violated.

Outlet Temperature Estimate An estimate for the outlet temperature may be optionally supplied in the Expander main data entry window to speed the calculations.


April 2014

Thermodynamic System The thermodynamic system of methods to be used for expander calculations may be selected by choosing a method from the Thermodynamic System dropdown list box on the Expander main data entry window.

Flash

General Information The Flash unit may be used to model any equilibrium calculation where two of the conditions are defined, e.g., temperature and pressure, pressure and enthalpy, etc. The phase equilibrium is determined and the product may be separated into product streams corresponding to the phases. The duty required, if any, to bring the feed to the final conditions is also reported. Both VLE and VLLE calculations are supported by this unit.

Feeds and Products A flash operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. A flash may have one or more product streams. The product phase condition for flash operations with one product stream is automatically set by PRO/II. For flash units with two or more product streams, the product phases must be specified in the Flash Product Phases window which is accessed by clicking Product Phases… on the Flash main data entry window. Product phases allowable include: vapor, liquid, decanted water/second liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified. Note that for Dew Point and Bubble Point calculations, only two product phases are allowed, vapor and liquid. The optional liquid product from a Dew Point calculation corresponds to a pseudo-stream with the equilibrium liquid composition and the optional vapor product from a Bubble Point calculation corresponds to the equilibrium vapor composition.

First Specification The temperature, pressure, or pressure drop from feed conditions is supplied by choosing the appropriate drop-down list box on the Flash main data entry window and supplying the value in the data entry field provided. Only one entry is allowed.

Chapter 9


Second Specification This specification is used in conjunction with the First Specification given above to define the equilibrium calculation desired. The Second Specification may be either a Unit Specification or a Product Specification as denoted by the radio buttons on the Flash main data entry window. These two types of specification are discussed separately below.

Unit Specification The desired second specification is chosen with the drop-down list box and the data entry supplied in the field provided. Options are: Pressure Drop or Pressure: These entries are only applicable when the temperature is chosen as the primary specification and correspond to an isothermal (constant temperature and pressure) flash. The Duty required to bring the feed to the specified conditions is calculated by PRO/II. Duty: This entry corresponds to an adiabatic (duty defined) flash. When the temperature is supplied as the primary specification, the pressure is computed. When the pressure or pressure drop is supplied as the primary specification, the temperature is computed. The duty may be positive (heating), negative (cooling), or zero (constant enthalpy calculation). Dew Point: The dew point pressure is computed when the temperature is supplied as the primary specification. The dew point temperature is determined when the pressure or pressure drop is provided as the primary specification. The Duty required to bring the feed to the specified conditions is calculated by PRO/II. Hydrocarbon Dew Point: The dew point pressure for the hydrocarbon portion of the stream is computed when the temperature is supplied as the primary specification. The dew point temperature is determined when the pressure or pressure drop is provided as the primary specification. This option is only applicable for thermodynamic systems which support a free water phase. The Duty required to bring the feed to the specified conditions is calculated by PRO/II. Water Dew Point: The dew point pressure for the water portion of the stream is computed when the temperature is supplied as the primary specification. The dew point temperature is determined when the pressure or pressure drop is provided as the primary specification. This option is only applicable for thermodynamic systems which support a free water phase. The Duty required to bring the feed to the specified conditions is calculated by PRO/II.


April 2014

Bubble Point: The bubble point pressure is computed when the temperature is supplied as the primary specification. The bubble point temperature is determined when the pressure or pressure drop is provided as the primary specification. The Duty required to bring the feed to the specified conditions is calculated by PRO/II. Isentropic: A constant entropy flash is calculated from feed conditions to final conditions. The product pressure is computed when temperature is given as the primary specification. The product temperature is given when the pressure or pressure drop is given as the primary specification. The Duty required to bring the feed to the specified conditions is calculated by PRO/II. Upper Dew Point: The Upper dew point pressure is available only when the temperature is chosen as the primary specification. This option is applicable for Vapor Liquid Equilibrium phases where a retrograde condensation region occurs. This option computes the upper dew point pressure if a temperature above the critical temperature and below the cricondentherm is supplied. The Duty required to bring the feed to the specified conditions is calculated by PRO/II.

Product Specification When this radio button is selected, the pressure is computed when the temperature is provided as the first specification such that a calculated stream parameter meets a specified value. When the pressure or pressure drop is supplied as the first specification, the temperature is computed. The Duty required to bring the feed to the final conditions is also calculated by PRO/II. The stream parameter specification is entered by clicking on the hypertext strings and uses the general PRO/II specification format. This format is further described in the SPEC/VARY/DEFINE section of this chapter. The stream parameter specification must correspond to one of the flash unit products and may be either an absolute or relative value. An absolute or relative tolerance value may also be supplied. Note that a default relative tolerance of 0.02 is used if none is given.

Entrainment Entrainment from one phase to another phase is requested in the Flash Drum Entrainment dialog. Access that window by clicking Entrainment… on the Flash main data entry window. Users must identify the From and To phases, and specify the quantity of entrainment as either (a) the fraction or percent of the donor phase, or (b) the absolute rate of material. The entrained material has the same composition as the donor phase. Since entrainment calculations are performed after the flash calculations, the resultant products may be different from the original flash specifications. Multiple entrainments are permitted.

Chapter 9


Temperature or Pressure Estimates Estimated temperatures or pressures may be supplied in the data entry boxes at the bottom of the Flash main data entry window. These estimates are optional, with a temperature estimate relevant when the first specification is the pressure or pressure drop, and a pressure estimate relevant when the first specification is the temperature. They do not apply to isothermal flash calculations.

Pseudo-stream Flow Rate Dew Point calculations allow an optional liquid pseudo-product, and Bubble Point calculations allow an optional vapor phase pseudo-product. These are virtual streams that are in phase equilibrium with the dew vapor or bubble point liquid, respectively. Although these pseudo-products are imaginary flows (they have actual rates of zero), they include all other equilibrium properties, such as temperature, pressure and composition. The pseudo-products are useful because other unit operations are able to reference their data and use it for other purposes, such as formulating Spec, Vary, and Define constructs. The rate (actually, an imaginary pseudo-rate) of a pseudo-stream may be supplied in the data entry field provided on the Flash main data entry window. This allows computing the property values of the imaginary phase based upon a useful flow rate datum. However, care must be taken to ensure that pseudostreams having non-zero rates neither feed other units nor participate in the flowsheet material and energy balances.

Thermodynamic System The thermodynamic system of methods to be used for flash calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the Flash main data entry window.

Flash With Solids

General Information The Flash with Solids unit models a flash drum unit operation with a solid product stream. If a solids product stream is to be present, you must use the Flash with Solids unit rather than the conventional Flash unit operation.


April 2014

Feeds and Products A Flash with Solids unit may have multiple feed streams, in which case the inlet pressure is assumed to be that of the feed stream with the lowest pressure. A Flash with Solids unit typically has four product streams: •

A vapor phase overhead stream from the flash drum section.

•

A liquid phase stream from the flash drum section.

•

A decanted water/second liquid from the solids separator section.

•

A solid phase bottom stream from the separator section. The default is complete separation of the solid from the fluid stream and, hence, there is no required input data for this unit.

The bottoms stream from the flash drum section feeding the solids separator is internal to the Flash with Solids unit and is not subject to specification by the user. The main data entry window for the Flash with Solids unit is identical to that of the ordinary Flash unit except that no specification of product phases by the user is required. The phases for the product streams are automatically specified by PRO/II and may be reviewed in the Flash Product Phases window accessible via the Product Phases… button on the Flash main data entry window. For further instructions on unit and product specifications, see the detailed discussions in the Flash section above (page 235, seq.). This page intentionally is left blank.

Flowsheet Optimizer

General Information The Flowsheet Optimizer maximizes or minimizes an objective function by varying one or more flowsheet variables while meeting a number of specifications. Optionally, you can place constraints on minimum and maximum values on the flowsheet variables. The objective function may be an operational criterion, such as maximum recovery or minimum loss, or an economic criterion, such as maximum profit or minimum cost. In order to optimize an economic function, you must first include a Calculator in the flowsheet in order to define the profit or cost. Then use the Optimizer to minimize or maximize the Calculator result.

Chapter 9


Objective Function Either you must choose either Maximize or Minimize as the objective function by selecting the appropriate radio button in the main Optimizer window. Enter the objective function by clicking the linked text string Parameter in the Objective Function field to make the Parameter window available selecting the unit or stream parameter to use as the Objective Function. This Parameter window is similar to the SPEC Parameter window, except that there is no entry allowed for the parameter value and tolerance. The Objective Function may be a single flowsheet parameter or a mathematical expression that relates two flowsheet parameters.

Variables The optimizer variables (VARY’s) are selected by clicking the linked text string Parameter in the Variables grid of the Optimizer main data entry window. In the Parameter window, designate the stream or unit parameter that will be varied, selecting from the same choices given above for the Objective Function. For unit or stream variables, you must also input minimum and maximum values. The SPEC/VARY/DEFINE section of this chapter gives more information on the VARY concept. The tables in that section list the flowsheet variables that may be used for SPEC’s and VARY’s for flowsheet optimizer units.

Variable Step Sizes and Limits You may enter limits on the step size for each control variable. Click the linked text string default step sizes in the main Optimizer window to open the Variable Step Sizes window. You may enter a relative minimum step size and/or absolute maximum step size per iteration in this window. You may also enter a non-default step size used to calculate the derivative in this window. The default relative step size depends on the Optimizer scaling option selected (see the section following titled Scaling of Optimization Variables). Alternatively, a user-supplied step size can be used in the calculations. The alternative step size may be sized on either a relative or absolute basis by selecting the appropriate radio button.

Specifications Specifications (SPEC’s) may be entered for flowsheet parameters other than the control variables. Click Specifications… on the Optimizer main data entry window to bring up the standard Specifications window. Check the Use Specifications box to enable the grid which contains the standard specification linked text. Enter the parameters for each Specification by clicking the appropriate text strings in each specification. Click the linked text string Parameter, to open the Parameter window where you can select the unit or stream parameter to use as the SPEC. The SPEC may be a single flowsheet parameter or a mathematical expression that relates two flowsheet parameters. Next, enter the value and the default tolerance for the SPEC by clicking on the appropriate text strings. See the


April 2014

SPEC/VARY/DEFINE section of this chapter for details on the generalized SPEC form.

Constraints Constraints may also be entered for flowsheet parameters other than the control variables. Constraints limit a variable to a specified range. Click Constraints… on the main Optimizer window to open the Constraints window from the SPEC/VARY system. Check the Use Constraints box to enable the constraint grid. Enter the parameters for each Constraint by clicking the appropriate text strings. Click the hypertext string Parameter to open the Parameter window where you can select the unit or stream parameter to use as the Constraints. The use of this window is analogous to the Parameter window used in selecting the SPEC above. The Minimum Value, Maximum Value, and the default tolerance values for the Constraints are entered by clicking on the appropriate text strings.

Calculation Options Number of Calculation Cycles Several options regarding the operation of the Optimizer may be specified by clicking Options… on the Optimizer main data entry window. The default for the number of calculation cycles is set by PRO/II as 18 plus the current number of variables. Alternatively, you may specify the number of cycles by selecting the appropriate radio button on the Options window.

Scaling of Optimization Variables By default, Optimizer scales the optimization variables in the convergence algorithm. This scaling can be suppressed by deselecting the Use Scaling box on the Options window. If scaling is not selected, the default value of the derivative step size that appears on the Variable Step Sizes window is increased from 2 percent to 5 percent.

Overall Error in any Variable -7

The default value for the overall error in any variable is 10 . You may enter a different value for the overall error in the corresponding data entry field in the Options window.

Minimum Relative Change in Objective Function The default value for the Minimum Relative Change in the Objective Function from one calculation cycle to the next is 0.005. You may enter a different value for the minimum relative change in the box on the Options window.

Chapter 9


Selecting the Next Unit Calculated After Control Variable is Updated Normally, the first unit operation in the calculation sequence that is affected by the control variable is the next unit calculated after the control variable is updated. Normally, this is determined automatically by the program. However, you must specify the next unit calculated whenever any optimization constraint or variable is a thermodynamic parameter. Specify the return unit by selecting the desired unit from the drop-down list box on the Options window.

Type of Thermodynamic Method The PRO/II Optimizer currently supports the use of both Rigorous and Local Thermodynamic Models during the perturbation steps. Specify the thermodynamic model by selecting one of the following options in the Type of Thermodynamic Model drop-down list box: Rigorous This option specifies that PRO/II will use rigorous thermodynamic calculation models. This is the default selection. Local TP Model This option specifies that PRO/II will generate local K-value models for T and P derivatives. Local TPx Model This option specifies that PRO/II will generate local K-value models for T, P, and Liquid composition derivatives. Local Taxi Model This option specifies that PRO/II will generate local K-value models for T, P, and Liquid and Vapor composition derivatives.

Advanced Options The Optimizer Advanced Options are intended for experienced users of PRO/II. If you are unsure how these features may apply to your simulation, consult SIMSCI Technical Support or refer to the PRO/II Reference Manual. 

Click Advanced Options... to specify additional options for the Optimizer.

Special Line Search Logic This option enables a line search mode method for optimization calculations. By default, this feature is Off. The option Specified Number of Trials in the drop-down list box enables this feature. When this feature is enabled, you may specify the maximum number of line search trials for any one optimizer cycle. The number must be a positive integer no greater than 20.


April 2014

Number of Independent Variables to Eliminate This allows specifying the number of independent variables to eliminate during the solution of the optimizer calculations.

Start Broyden Updating at Cycle This allows specifying the optimization cycle at which Broyden Updating begins. By default, this option is Off. Specify a positive integer greater than 1 to enable this feature.

Derivative Analysis By default, this option is Off. Select On in the drop-down list to produce an analysis printout of the derivative step sizes for each optimizer cycle; in addition, a modified perturbation step size will be suggested, if appropriate.

Limit Optimization Step Sizes By default, this option is Enabled (Yes). When enabled, this option limits the step sizes taken by the optimizer to 30, 60, and 90 percent of the upper or lower bounds during optimization cycles 1, 2, and 3, respectively. This is intended as a safety feature to prevent the Optimizer from moving too far, particularly when the derivatives are inaccurate. Selecting No in the dropdown list box disables this feature.

Separate Shadow Price Output File Once the flowsheet optimization has converged and the appropriate operating conditions have been determined, the shadow prices or Lagrange multipliers can be used to assess the sensitivity of the objective function to the specifications, constraints and bounds. For maximization problems, a positive shadow price indicates that the constraint is being pushed against its upper bounds, a negative shadow price indicates that the lower bound is still active, and a zero shadow price indicates that the constraint does not affect the solution By default, printout of these values is disabled (the None option in the Separate Shadow Price Output File drop-down list box). Brief

This option produces a separate output report with the same file name as the input file (with a .shd extension). This report contains the IDs of the variables, specifications, and constraints, along with their corresponding shadow prices as part of the standard output report.

All

This option produces a separate output report with the same file name as the input file (with a .shd extension) containing a detailed summary of the final Optimizer solution. This summary includes the

Chapter 9


values of the objective function, all variables, specifications, and constraints, along with the shadow prices for all active bounds and constraints. Complete technical details may be found under the topic Flowsheet Solution Algorithms in the PRO/II Reference Manual.

Print Results for Flowsheet Optimizer The default is to suppress printing of a convergence report. Click Print Options… on the main Optimizer window to open the Print Options window. Select the desired printout level from a drop-down list that includes the print levels History, Brief, and All. By default, no intermediate printout is produced. Print-out levels for intermediate printout of derivative and/or variable values can be selected from a drop-down list which includes the print levels None, Print after each cycle, or Print after the final cycle. The program limits the options for the variable printout selection such that the level of printout is greater than or equal to the derivative printout option. Select the Include Convergence Plots check box to generate a plot of the convergence diagnostics.

Heat Exchanger, LNG

General Information The LNG Heat Exchanger simulates the exchange of heat between any number of hot and cold streams. The exchanger is divided into cells representing the individual cross-flow elements. Cells are designated as Hot, where the streams are cooled or as Cold where they are heated. The unit must contain at least one hot cell and one cold cell. The number of cells is initially defined on the LNG Heat Exchanger Configuration window that appears when the unit is first placed on the PFD. Cells may be added or deleted in the main LNG Heat Exchanger window.

Feeds and Products Each cell may have one or more feed streams. If multiple feed streams are defined, the mixed feed is flashed at the lowest feed stream pressure. A multiphase product from a cell may be separated into streams containing one or more phase. The allowable product stream phases are vapor, liquid, decanted


April 2014

water, or mixed (vapor + liquid). A mixed phase product is not allowed with a vapor or a liquid product. The decanted water product is also used as the second liquid product phase with rigorous VLLE calculations. If a cell has more than one product stream, the phases must be allocated to the streams in the Product Phases window. This window is accessed via the Cell Data… button in the main LNG Heat Exchanger window, then via the Product Phases… button in the now open LNG Heat Exchanger Cell Data window.

Performance Specifications Any cell may have either a duty or an outlet temperature specification. However, at least one cell must remain unspecified. The product streams from all unspecified cells leave the exchanger at the same temperature.

Cell Data The pressure drop for each cell defaults to zero. Pressure drop values are entered in the LNG Heat Exchanger Cell Data window. The thermodynamic system used for the calculations for an individual cell may also be changed in this window.

Zones Analysis Zones Analysis may be requested in the LNG Heat Exchanger Zones Analysis window accessible via the Zones Analysis… button on the main data entry window. This feature allows internal temperature crossovers and pinch points to be identified by dividing the exchanger into a number of zones. Warnings are issued if crossovers or pinch points are found. The Zones Analysis calculations are normally performed when the exchanger is calculated. However, if the exchanger is in a recycle, computation time may be saved by performing the analysis at output time. Zone Analysis will always be performed at calculation time if required by Controller specifications on the LNG heat exchanger.

Print Options The Print Options window is opened via the Print Options… button on the main data entry window. A number of different Y versus X plots may be generated for temperature, duty, and UA. The options are: •

Temperature vs. Duty (default)

•

UA vs. Duty (default)

•

∆T vs. Temperature (default)

•

∆T vs. Duty

Chapter 9


•

UA vs. ∆T

•

Duty vs. Temperature.

Thermodynamic System The thermodynamic system of methods to be used for LNGHX calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the LNG Heat Exchanger main data entry window. Note: The thermodynamic system used for the calculations for an individual cell (specified in the LNG Heat Exchanger Cell data window) overrides this thermodynamic system for specific cells.

Heat Exchanger, Air Cooled

General Information An Air Cooled Heat Exchanger (ACE) uses air as the cooling medium to remove heat from a process fluid. The process fluid is a stream that flows through the tube-side of the ACE through a tube bundle. Configuration options allow either heating or cooling. The air side is analogous to the shell side of a shell-and-tube exchanger, but the air is propelled using fans. A forced draft configuration locates fans at the air entrance below the tube bundle. An induced draft configuration places the fans above the tube bundle at the air exit. The model allows a single (air side) bay that exchanges heat with one or more (process side) tube bundles configured in series, in parallel, or both. Tube side options configure one tube bundle. When more than one bundle are configured, all bundles have the same physical configuration. Tube-side options allow tube fins and tube-side nozzles. The model executes in either rating (performance) mode or design (sizing) mode. The default rating mode computes heat transfer and other performance data based on a fixed exchanger configuration. It allows either none or one operating specification. Design mode varies the physical dimensions of the exchanger to satisfy a performance specification. It requires exactly one operating specification with additional design constraints on the physical configuration.

Feeds and Products Both the air side and the tube side of the exchanger require at least one feed stream (10 are allowed) and at least one product stream (4 are allowed). All feeds and products are declared using keyword input, or by laying them down


April 2014

and connecting them to the ACE directly on the PFD window of the simulation. ACE data entry windows do no support configuring feed or product streams. The ACE model now supports ‘Air‘ as Utility stream. To use ‘Air’ as Utility, air side ports need not be connected and also Air / Oxygen and Nitrogen need not be defined in the Component Selection DEW. Air as a Utility stream may be specified by unchecking the 'Air is a Process Stream' check box on the Specifcation window and specify the Utility side specifications. The feed to the air side should deliver a process stream that represents air and possibly some contaminates or trace components. For example, component AIR could be present, or air could be represented by a mixture of nitrogen and oxygen. However, there are no explicit constraints upon the composition of the air side feed. Other mixtures that define other gaseous fluids are allowed. Feeds to the tube side may be any process streams that include a fluid (nonsolid) phase. When multiple feed streams are defined on either side, the mixed feed is flashed at the lowest feed stream pressure. A multi-phase product from the exchanger may be separated into separate draw streams containing one or more phases. The air side often takes a single product draw, since the air flow typically represents a utility. Multiple product draws are more common on the tube (process) side. The allowable product stream phases are vapor, liquid, and mixed (vapor + liquid). A mixed phase product is not allowed with a vapor or a liquid product. When the water DECANT=ON option is active, an additional decanted water draw is supported. The water decant product also serves as the second liquid product phase when modeling rigorous VLLE calculations. PRO/II Online Help provides extensive information about the various data entry windows and the input data requirements. More complete information about available options and modes of operation are available in the PRO/II Keyword Manual. In the chapter titled “Air Cooled Heat Exchanger”.

Heat Exchanger, Rigorous

General Information The Rigorous Heat Exchanger simulates the operation of an existing heat exchanger. The geometry of the unit has to be defined and the unit is rated to determine the duty, exit temperatures, and pressure drops. The exchanger duty, or one of the exit temperatures, may be defined. In this case, the fouling resistance is calculated.

Chapter 9


Feeds and Products Each side of the exchanger may have one or more feed streams. If multiple feed streams are defined, the mixed feed is flashed at the lowest feed stream pressure. A multiphase product from the exchanger may be separated into streams containing one or more phase. The allowable product stream phases are vapor, liquid, decanted water and mixed (vapor + liquid). A mixed phase product is not allowed with a vapor or a liquid product. The decanted water product is also used as the second liquid product phase with rigorous VLLE calculations. If either side has more than one product stream, the phases must be allocated to the streams in the Product Phases window accessed via the Product Phases… button in the Rigorous Heat Exchanger–Feeds and Products Data window.

Calculation Type The calculation type is selected from a drop-down list in the Rigorous Heat Exchanger window. The available options are: Rating: Determine the heat transferred with the defined area and fouling factors. This is the default. Fixed Duty: Determine the fouling factors and exit temperatures from the defined duty. Tube Outlet Temperature: Determine the duty, fouling factors, and shell exit temperature from the defined tube outlet temperature. Shell Outlet Temperature: Determine the duty, fouling factors, and tube exit temperature from the defined shell outlet temperature. If the selected calculation type is not Rating, a value must be supplied for the duty or exit temperature as appropriate.

Exchangers Attached to Columns Exchangers may be attached to any tray of a column for which a duty is defined, either heating or cooling. To attach an exchanger to a column, double-click Attach to Column… for the shell or tube side on the Rigorous Heat Exchanger– Feed and Products Data window and supply the appropriate information in the window provided. A column internal stream is considered as one side of the exchanger and a process stream is defined for the other side. Attached exchangers may be used to represent the condenser or reboiler for the column, a pumparound, or side heater/cooler. For side heaters and coolers, the column stream may be the vapor or liquid from the tray to which the exchanger is attached, the vapor from the tray below, or the liquid from the tray above.


April 2014

If the Calculation Type does not fix the exchanger duty or one of the outlet temperatures, the exchanger duty will be fixed by the column heater or cooler. It is generally best to allow the column operation to determine the duty required to meet the defined performance. If the duty is fixed by an exchanger specification, it is considered a “fixed” duty for the column calculations.

Overall Configuration The overall configuration is defined in the Rigorous Heat Exchanger window by entering one or more of the configuration parameters: •

Number of Tubes/Shell

•

Area/Shell

•

Shell Inside Diameter

A value for at least one of these parameters must be supplied. If any of these parameters is missing, it will be calculated from the others.

Configuration Data The configuration details are defined in the Rigorous Heat Exchanger Configuration Data window accessible via Configuration… on the main data entry window. All data in this window have default values: Number of Shells in Series: This is the number of identical shells connected in series in the unit. Both shell and tube sides are considered to be piped in series. The default is 1 shell. Number of Shells in Parallel: This is the number of identical shells connected in parallel in the unit. Both shell and tube sides are considered to be piped in parallel. The default is 1 shell. Number of Tube Passes/Shell: This can be any integer value between 1 and 16. The default is 2. Odd numbered values are allowed, but are not recommended. Orientation: The exchanger orientation is selected from the drop-down list as either Horizontal or Vertical. The default is Horizontal. Configuration: The direction of fluid flow is selected from the drop-down list as either Countercurrent or Cocurrent. The default is Countercurrent. TEMA Type: The three characters for the TEMA type (front, shell and rear of the exchanger) are selected separately from drop-down lists. The default is AES.

Chapter 9


Tube Data Details of the exchanger tubes are entered in the Rigorous Heat Exchanger Tube Data window which is accessed via Tubes… on the main data entry window. All tube data have default values. Length: The nominal tube length includes the thickness of both tube-sheets. For U-tubes, it includes the thickness of the tube sheet and the last baffle. The length defaults to 20 ft (6.1 m). Outside Diameter: The tube outside diameter defaults to 0.75 inches (19.05 mm). Thickness: The tube thickness may be defined as: Inside Diameter Wall Thickness BWG Bare tubes default to an inside diameter of 0.58402 inches (14.834 mm). Finned tubes default to an inside diameter of 0.49598 inches (12.573 mm). Pitch: The center-to-center distance between tubes defaults to 1.0 inch (25.4 mm). Pattern: The tube pattern is selected from the drop-down list. The options are Triangular–30 Degrees, Square–90 Degrees (default), Rotated Triangular–60 Degrees, and Rotated Square– 45 Degrees. Sheet Thickness: The tube sheet thickness is calculated if it is not supplied.

Fin Data The default is not to have finned tubes. If fins are specified, the surface area may be entered directly or calculated from the fin data. Extended Surface Area: This is the total surface area of the tubes including the finned and bare surface areas. A value entered here, overrides the calculated area. Fins/Inch: This is the number of fins per inch of tube length. (Default is 19). Thickness: The fin thickness defaults to a value in inches equal to 0.5/ (Fins per Inch). Height Above Root: The fin height above the root defaults to a value equal to (Tube Outside Diameter - Root Diameter)/2.


April 2014

Root Diameter: The root diameter is the tube diameter at the base of the fins and it defaults to 0.625 inches.

Baffle Data Details of the exchanger baffles are entered in the Rigorous Heat Exchanger Baffle Data window accessible via Baffles… on the main data entry window. All baffle data have default values. Baffle Type: The type is selected from the drop-down list. The options are No Baffles, Single (default), Single Baffles - No Tubes in Window and Double. Baffle Geometry Data: The baffle cut is the height of the window divided by the shell inside diameter and it defaults to 0.2. Alternatively, the Net Free Area Ratio may be entered instead. This is the area of the window divided by the cross-sectional area of the shell. Center Spacing: If a value is not supplied, the baffle center-to-center spacing is calculated by default to be 0.2*(Shell Inside Diameter). Any value entered will be ignored if both Inlet Spacing and Outlet Spacing are defined and the value will be calculated to provide even spacing. Inlet Spacing: This is the center-to-center spacing between the tube sheet and the inlet baffle. If the inlet spacing is not supplied, it is calculated to meet the center spacing or, if no center spacing is defined, it defaults to 5 inches (133 mm) for bare tubes or 3 inches (88 mm) for finned tubes. Outlet Spacing: This is the center-to-center spacing between the tube sheet and the outlet baffle. If the outlet spacing is not supplied, it is calculated to meet the center spacing or, if no center spacing is defined, it defaults to 5 inches (133 mm) for bare tubes or 3 inches (88 mm) for finned tubes. Thickness: If a value is not supplied, the baffle thickness defaults to 0.1875 inches (4.763 mm). Number of Sealing Strips: This is the number of pairs of sealing strips per cross-flow pass. It defaults to zero.

Film Coefficient Data Film Coefficient Data are entered in the Rigorous Heat Exchanger Film Coefficient Data window accessible via Film Coefficients… on the main data entry window. These data provide adjustment factors and override values for the heat transfer parameters. Overall U-value Estimate: This is the initial value for the heat transfer coefficient 2 2 used in the calculation. The default is 50 Btu/hr·ft ·°F (244.1 kCal/hr·m 2 ·°C or 1021.9 kJ/hr·m ·K).

Chapter 9


Overall U-value Scale Factor: This is a multiplier which is applied to all calculated heat transfer coefficients. It can be used in order to match plant data more closely. It defaults to 1.0.

Tubeside and Shellside Data The following items have separate entries for each side of the heat exchanger. Scale Factor: This is a multiplier which is applied to the film coefficient for the specified side of the exchanger. It defaults to 1.0. Coefficient: If a value is entered, it overrides the calculated film coefficient for the specified side. 2

Fouling Resistance: Thermal fouling resistance defaults to 0.002 ft ·hr·°F/Btu 2 2 (0.00041 m ·hr·°C/kCal or 0.00010 m ·hr·K/kJ). If a duty or exit temperature is specified, the fouling will be calculated. Fouling Thickness: The thickness of the fouling layer may be entered to model its effect on the pressure drop. The default value is zero.

Pressure Drop Data Pressure drop data are entered in the Rigorous Heat Exchanger Pressure Drop Data window accessible via Pressure Drop… on the main data entry window. These data provide adjustment factors and override calculated values for the pressure drops. All data may be defaulted. By default the pressure drops are calculated for each side of the exchanger. A scale factor may be applied to the calculated value for either side or the pressure drops may be overridden. DP Scale Factor: This is a multiplier which is applied to the pressure drop for the specified side of the exchanger. It defaults to 1.0. DP / Shell: If a value is entered, the pressure drop per shell overrides the calculated pressure drop for the specified side. DP / Unit: If a value is entered, the pressure drop for the exchanger unit overrides the calculated pressure drop for the specified side. Shellside Pressure Drop Method: The method may be selected from Bell (default) for the Bell-Delaware method or Stream for the stream analysis technique.

Print Options Additional output reports are selected in the Rigorous Heat Exchanger Print Options window accessible via Print Options… on the main data entry window.


April 2014

Extended: By default, a standard TEMA data sheet is produced for the exchanger. Checking the Extended check box produces an additional data sheet with information about stream properties, heat exchanger configuration and hydrodynamics. Zones: Checking the Zones check box produces an additional table showing the phase and zone boundaries used to calculate the duty-averaged logmean-temperature difference. Zones Plot: Checking the Zones Plot check box produces a plot showing the phase and zone boundaries used to calculate the duty-averaged logmean-temperature difference.

Material Data Tube and shell material property data are entered in the Rigorous Heat Exchanger Material Data window accessible via Materials… on the main data entry window. The default material is carbon steel. A different material may be selected from a drop-down list which shows the materials in the library. Individual properties of the selected material may be overridden. Alternatively, the user may select User-added Material from the list and then supply the name and properties of the material. The list of materials in the library is tabulated below. Heat Exchanger Materials of Construction Material

Density

Conductivity

Label

lb/ft

3

kkg/ 3 m

Btu/ hr.ft.°F

kCal/ hr.m.°C

W/m.K

Carbon Steel

CARB STL

490.8

7862

30.0

44.6

51.9

Carbon-moly Steel 0.1C, 0.5Mo

CARB MLY

493.2

7900

29.0

43.2

50.2

Chrome-moly Steel 1.0Cr, 0.5Mo

CHRM MLY

490.1

7851

27.0

40.2

46.7

Low Chrome Steel 2.25Cr, 1.0Mo

LOW CHRM

487.0

7801

25.0

37.2

43.3

Medium Chrome Steel 5.0Cr, 1.0Mo

MED CHRM

480.7

7700

21.0

31.2

36.3

Description

Chapter 9


Heat Exchanger Materials of Construction Material

Density

Conductivity

Label

lb/ft

3

kkg/ 3 m

Btu/ hr.ft.°F

kCal/ hr.m.°C

W/m.K

STR CHRM

487.0

7801

14.0

20.8

24.2

304 Stainless Steel 18Cr, 8Ni

304 S.S.

501.1

8027

9.3

13.8

16.1


310 S.S.

501.1

8027

7.8

11.6

13.5


316 S.S.

501.1

8027

9.4

14.0

16.3


321 S.S.

494.2

7916

9.2

13.7

15.9

Aluminum 1060 H14

A1060H14

170.0

2723

128.3

190.9

222.1

Aluminum 1100 Annealed

A1100 AN

169.3

2712

128.3

190.9

222.1

Aluminum 3003 H14 Annealed

A3003H14

171.1

2741

111.0

165.2

192.1

Aluminum 3003 H25 Annealed

A3003H25

171.1

2741

111.0

165.2

193.1

Aluminum 6061 T4 Tempered

A6061 T4

169.3

2712

95.0

141.4

164.4

Aluminum 6061 T6 Tempered

A6061 T6

169.3

2712

95.0

141.4

164.4

Copper

COPPER

556.4

8913

225.0

334.2

389.4

Arsenical Copper AS

COPPER

560.0

8970

187.0

278.3

323.6

Copper Nickel 90/10

CUNI9010

559.0

8954

26.0

38.7

45.0

Copper Nickel 80/20

CUNI8020

558.5

8946

22.0

32.7

38.1

Copper Nickel 70.30

CUNI7030

585.0

9371

17.0

25.3

29.4

Copper Nickel 60/40

CUNI6040

554.7

8885

12.9

19.2

22.3

Red Brass 85Cu, 15Zn

RED BRAS

546.0

8746

92.0

136.9

159.2

Description Straight Chrome Steel 12Cr


April 2014

Heat Exchanger Materials of Construction Material

Density

Conductivity

Label

lb/ft

3

kkg/ 3 m

Btu/ hr.ft.°F

kCal/ hr.m.°C

W/m.K

ADMRALT Y

531.0

8506

64.0

95.2

110.8

Commercial Brass 55Cu, 34Zn

COM BRAS

529.0

8474

67.0

99.7

116.0

Muntz Metal 60Cu, 40Zn

MUNTZ

524.0

8394

71.0

105.7

122.9

Aluminum Bronze 93Cu, AL BRONZ 5Al

510.0

8169

48.0

71.4

83.1

Aluminum Brass 78Cu, 2Al

AL BRASS

520.0

8330

58.0

86.3

100.4

NICKEL

556.4

8913

45.2

67.3

78.2

Description Admiralty Brass 71Cr, 28Zn, 1Sn

Nickel Annealed Low Carbon Nickel Annealed

L CRB NI

554.7

8885

35.0

52.1

60.6

Monel Nickel 70Ni, 30Cu

MONEL NI

551.2

8829

14.5

21.6

25.1

Inconel 600 76Ni, 16Cr, 8Fe

INCNL600

525.3

8414

8.7

12.9

15.0

Titanium Grade 2

TITANIUM

281.6

4511

9.5

14.1

16.4

Nozzle Data The default nozzle type and sizes can be overridden in the Rigorous Heat Exchanger Nozzle Data window accessible via Nozzles… on the main data entry window. The default is to use conventional nozzles with calculated inside diameters. Nozzle data only affects the calculated pressure drop in the exchanger. Use Tube Side Nozzle or Use Shell Side Nozzle: If either check box is unchecked, the nozzle pressure drop will not be calculated for that side of the exchanger. Inside Diameter: The calculated diameters may be overridden. The Inlet and/or Outlet diameter may be entered.

Chapter 9


Use Annular Shell Side Nozzles: If this box is checked, the pressure drop will be calculated for annular rather than conventional nozzles. In this case, click Enter Data… to open the Annular Nozzle Data window to enter the nozzle details. The required data are: •

Inlet and outlet annular passage lengths

•

Inlet and outlet groove areas

•

Inlet and outlet annular-shell wall clearances

Thermodynamic System The thermodynamic system of methods to be used for each side of the rigorous heat exchanger may be selected by choosing a method from the Thermodynamic System drop-down list box on the Rigorous Heat Exchanger main data entry window.

Heat Exchanger, Simple

General Information The Simple Heat Exchanger may be used to heat or cool a single process stream, exchange heat between two process streams, or exchange heat between a process stream and a utility stream. Rigorous calculations may be performed for VLLE systems. It is also possible to attach an exchanger to any tray of a distillation column and exchange heat between a process stream and a column internal stream, either liquid or vapor.

Feeds and Products For reference, streams and products are grouped according to the side of the exchanger as “hot” or “cold”, where the feed stream(s) on the hot side are cooled and the feed stream(s) on the cold side are heated. Multiple process feed streams are permitted, with the lowest stream pressure used as the inlet pressure. The product from each side of an exchanger may be phase separated as desired into multiple product streams, where products may be liquid, vapor, mixed phase, and decanted water (hydrocarbon systems only). The “water” product stream may also be used to represent a second liquid phase for systems in which rigorous modeling of VLLE thermodynamics is considered.


April 2014

Feed and product streams are accessed via the Heat Exchanger Process Streams window which is opened by clicking Process Stream… on the Heat Exchanger main data entry window. The product phase condition for units with one product stream is automatically set by PRO/II. For simple heat exchangers with two or more product streams from a given side, the product phases must be specified in the Product Phases window accessible by clicking Product Phases… on the Heat Exchanger Process Streams window. Product phases allowable include: vapor, liquid, decanted water, heavy liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified.

Utility Streams For simple heat exchangers with one process side, a hot or cold utility stream may be defined. The required utility rate for the specified heat transfer is always computed. Utility streams may be specified by clicking Utility Stream… on the Heat Exchanger main data entry window to access the appropriate hot or cold utility window. Cold utility streams are supplied in the Heat Exchanger Cold Side Utility window. Options are: Water: Temperature in and out must be supplied. Sensible heat transfer only. Air: Temperature in and out must be supplied. Sensible heat transfer only. Refrigerant: A designated component is vaporized at its saturation pressure or temperature. Latent heat transfer only. Hot utility streams are supplied in the Heat Exchanger Hot Side Utility window. Options are: Steam: Steam is condensed at its saturation temperature or pressure. Latent heat transfer only. Heating Medium: A designated component is condensed at its saturation temperature or pressure. Latent heat transfer only.

Configuration Data Configuration data are supplied in the Heat Exchanger Configuration Data window accessed by clicking Configuration… on the main data entry window. These data only apply to exchangers with two sides and are optional for all exchangers for which a Performance Specification is provided (see below). Flow Direction: Countercurrent or cocurrent. Default is countercurrent. Tube and Shell Passes: When supplied, an N -2N configuration is always assumed, where the number of tube passes is twice the number of shell

Chapter 9


passes. The “FT” LMTD correction factor is computed based on a correlation for N -2N exchangers. Default is two tube and one shell pass, i.e., true countercurrent flow. FT Factor: The LMTD correction factor for the exchanger. Note that this entry is mutually exclusive with the Tube and Shell Passes.

Performance Specifications Exchanger performance is specified in the Heat Exchanger Specifications window accessed via Specifications… on the main data entry window. Exchanger performance may be specified in a variety of ways: Outlet Temperature: Temperature out for hot or cold process fluid. Temperature Approach (Two-sided exchangers only) •

HOCO: Hot out minus cold out.

•

HOCI: Hot out minus cold in.

•

HICO: Hot in minus cold out.

•

Minimum: Smaller of HOCI and HICO.

•

Minimum Internal Temperature Approach (MITA): Minimum internal approach based on a zones analysis for the exchanger.

Duty: Overall heat transfer duty for the exchanger. Outlet Stream Liquid Fraction: The liquid fraction for the hot or cold side exit fluid where 1.0 indicates bubble point and 0.0 indicates dew point conditions. Degrees of Superheat: The degrees of superheat (above the dew point) for the hot or cold side exit fluid. Degrees of Subcooling: The degrees of subcooling (below the bubble point) for the hot or cold side exit fluid. Overall Heat Transfer Coefficient (U): The area is calculated from this entry when not supplied. When both U and Area are given, the heat transfer is computed to satisfy the U*Area and no other performance specifications are allowed for the exchanger. Exchanger Area: The overall heat transfer coefficient for the exchanger is calculated from this entry when not supplied. When both U and Area are given, the heat transfer is computed to satisfy the U*Area and no other performance specifications are allowed for the exchanger. Lumped UA Specification: The product of overall heat transfer coefficient and exchanger area may be supplied directly.


April 2014

Individual U and Area Specification: Individual values for the overall heat transfer coefficient and exchanger area may be supplied directly. Maximum U *Area: A maximum U*Area may be supplied to limit the heat transfer otherwise determined by a performance specification if necessary. This specification is not allowed when either a Lumped UA specification or the exchanger overall U and Area have been supplied individually.

Zone Analysis Zone analysis is requested by clicking Zones Analysis… on the main data entry window. The duty-weighted LMTD of exchangers that encounter phase changes may be computed by dividing the exchanger into at least five zones of equal duty. More zones may be requested as desired. Zones analysis is automatically performed during convergence calculations for exchangers with MITA, a zoned MTD specification, a UA specification, or both a U and an AREA specification together. Each of these configurations requires a zone analysis to reach a solution. Warning messages are given for temperature crossovers. For other types of specifications, the zone analysis may be performed during exchanger calculations or at the completion of all calculations, as requested. Usually, the only zone analysis of interest is the one performed on the final converged exchanger. In this case, convergence calculations may be reduced significantly by requesting zone analysis during OUTPUT rather than during calculations.

Exchangers Attached to Columns Exchangers may be attached to any tray of a column for which a duty is defined, either cooling or heating. To attach an exchanger to a column, click Attach to Column… on the main data entry window and supply the appropriate information in the window provided. An internal column stream is considered as one side of the exchanger; a process stream or utility stream defined for the exchanger is the other side. Note that for utility streams, the duty must be determined by the column calculations. Attached exchangers may be used to represent the condenser or reboiler for the column, a pumparound cooler, or a side heater or cooler. For side heaters and coolers, the column stream may be: the vapor or liquid from the tray to which the exchanger is attached, the vapor from the tray below the tray to which the exchanger is attached, or the liquid from the tray above the tray to which the exchanger is attached. It is generally best to let the exchanger duty be determined in the column operation to meet a desired separation criterion. If the duty is defined by a

Chapter 9


performance specification for the exchanger, it is considered a “fixed” duty for column calculations.

Thermodynamic System The thermodynamic system of methods to be used for each side of the simple heat exchanger may be selected by choosing a method from the Thermodynamic System drop-down list box on the Heat Exchanger main data entry window.

Heating/Cooling Curves

General Information The Heating/Cooling Curve utility module develops heating or cooling curves for any stream in the flowsheet. The tables are a composite of equilibrium flashes, and present the data typically required for the design of heat transfer equipment. Curves may be generated by using equal temperature increments or equal duty increments. Additional points are included when phase boundaries are crossed. For the Flash, Heat Exchanger, and Column unit operations, a convenient means is provided to retrieve the streams involved in heat transfer and generate curves based on the actual duties for the units. For other flowsheet streams, you may define the desired temperature or duty ranges for the curves. In addition to the standard thermal properties, additional properties may be requested for the reports. These properties include physical, critical, thermodynamic, transport, and petroleum properties.

Heating/Cooling Curves for Flowsheet Streams A drop-down list box is used to retrieve flowsheet streams for which curves are desired in the Heating/Cooling Curves main data entry window. After selecting a stream, click Enter Data to open the Heating/Cooling Curve for Flowsheet Stream window. This window is used to select the boundaries for the curves, type of curves, number of points for the curves, and the report options. A combination of two specifications is used to define the type and boundaries for the curves. Curves may be at equal temperature increments, equal duty increments, constant entropy, or may be the dew point or bubble point curve for the fluid. Dew and bubble points may be calculated at defined pressures or at defined temperatures. When the temperature and pressure ranges are defined for a curve, the resultant points are always at equal temperature/pressure


April 2014

intervals. When a temperature, pressure, or duty increment is defined for a curve, the starting point is always taken to be the current stream conditions. The number of points for the curves may be selected on this form by replacing the default value of 11. Crossing phase boundaries adds points to the report. The additional points represent the phase transitions. The following table describes the exact calculation points as a function of specifications given: First Second Starting Point Increments Specification Specification

Pressure Increment

User supplied temperature, stream pressure

Pressure Range

User supplied temperature, user supplied pressure

Dew Point Temperature Range

User supplied temperature, dew point

Bubble Point

User supplied temperature, bubble point

Pressure Increment

Stream temperature, stream pressure

Chapter 9

Equal temperature and pressure increments Equal temperature and pressure increments Equal temperature increments at dew point. Equal temperature increments at bubble point Equal temperature and pressure increments


Pressure Range

Stream temperature, user supplied pressure

Temperature Increment

Dew Point

Stream temperature, dew point

Bubble Point

User supplied temperature, bubble point

Equal temperature increments at dew point. Equal temperature increments at bubble point


User supplied pressure, stream temperature

Equal temperature and pressure increments

Temperature Range

User supplied temperature,


user supplied pressure

Pressure Range



Dew Point

User supplied pressure, dew point

Equal pressure increments at dew point.

Bubble Point

User supplied pressure, bubble point

Equal pressure increments at bubble point

April 2014

Pressure Increment

Chapter 9


Stream pressure, stream temperature


Temperature Range

Stream pressure, user supplied temperature


Dew Point

User supplied pressure, dew point

Equal pressure increments at dew point.

Bubble Point

User supplied pressure, bubble point

Equal pressure increments at bubble point

Temperature and pressure Increments

Stream pressure, stream temperature.

Equal pressure and enthalpy increments with final enthalpy evaluated at T = del T * (points – 1) and P = del P * (points-1)


Pressure and Enthalpy Increments


Equal pressure and enthalpy increments with final enthalpy evaluated at H = Hi + Hdif

Pressure Range and Enthalpy Increment

User supplied pressure, stream enthalpy (reflashed at pressure)

Equal pressure and enthalpy increments with final enthalpy evaluated at H = Hi + Hdif

Temperature and Pressure Ranges

User supplied temperature and pressure

Equal pressure and enthalpy increments with final enthalpy evaluated at user supplied temperature and pressure

Enthalpy Change (Adiabatic)


April 2014

Isentropic (Constant Entropy)

Temperature Increment and Pressure Range

Stream temperature and user supplied pressure

Equal pressure and enthalpy increments with final enthalpy evaluated at T = del T * (points – 1)

Pressure Increment


Equal pressure increments and constant entropy

Pressure Range

User supplied pressure, stream temperature

Equal pressure increments and constant entropy



Equal temperature increments and constant entropy

Temperature Range

Stream pressure, user supplied temperature

Equal temperature increments and constant entropy

A check box may be used to select printout of liquid activity coefficients, vapor fugacity coefficients, and Pointing correction factors for thermodynamic systems

Chapter 9


based on liquid activity coefficients. The equilibrium K-values for the components may also be selected for printout with a check box.

Heating/Cooling Curves for Unit Operations A drop-down list box is provided for selection of unit operations for which curves are desired in the Heating/Cooling Curves main data entry window. Units for which curves may be requested include the Flash, Heat Exchanger, and Column. To select the options for the unit: 

Click Enter Data adjacent to the unit name.

The appropriate window for the unit operation appears for selection of curve options. In each case, the user may specify printout options for liquid activity coefficients, vapor fugacities, and Poynting corrections for thermodynamic systems based on liquid activity coefficients. The equilibrium K-values for the components may also be selected for printout.

Heating/Cooling Curves for Flash Units Check boxes and radio buttons are used on the Heating/Cooling Curves for Flash Drum window to select the options for the curves. The temperature and pressure range is predefined as the inlet and outlet conditions for the Flash. The curves may be defined as isothermal, i.e., at equal temperature increments, or as adiabatic, i.e., at equal duty increments. The number of points for the curves may be selected on this form by replacing the default value of 11. Crossing phase boundaries adds points the report. The additional points represent the phase transitions.

Heating/Cooling Curves for Heat Exchangers Check boxes and radio buttons are used on the Heating/Cooling Curves for Heat Exchangers window to select the options for the curves. The temperature and pressure range is predefined as the inlet and outlet conditions for each side of the Heat Exchanger. The curves may be defined as isothermal, i.e., at equal temperature increments, or as adiabatic, i.e., at equal duty increments. The number of points for the curves may be selected on this form by replacing the default value of 11. Crossing phase boundaries adds points the report. The additional points represent the phase transitions. Note: 11 points result in 10 intervals.

Heating/Cooling Curves for Columns Column streams are selected in a drop-down list box on the Heating/Cooling Curves for Column Internal Streams window. Streams available include the condenser and reboiler feeds, and feeds to trays with duties such as side


April 2014

reboilers and pumparound coolers. The curves may be defined as isothermal, i.e., at equal temperature and pressure increments, or as adiabatic, i.e., at equal enthalpy and pressure increments. The temperature and duty ranges are predefined as the unit operating conditions. A pressure range may be added to pumparound streams to simulate the effects of pumping. The number of points for the curves may be selected on this form by replacing the default value of 11. Crossing phase boundaries adds points the report. The additional points represent the phase transitions. Note: 11 points result in 10 intervals.

Standard Reports Standard reports include the data in the table below: Property

Total Feed

Temperature

X

Pressure

X

Molar Flow Enthalpy

X

Weight Flow Molar Entropy

X

Vapor

Liquid

X

X

X

X

X

X

X

X

Additional Stream Properties These properties are requested by clicking Report Additional Stream Properties on the Heating/Cooling Curve main data entry window. These properties are reported in addition to the standard reports for all curves selected for the Heating/Cooling Curve.

Additional Stream Properties Reports Additional reports may include the data tabulated below: Property

Vapor

Liquid

Molecular Weight

X

X

Actual Density

X

X

Volumetric Flow

X

X

Chapter 9

Total Feed


Compressibility Factor

X

Specific Gravity

X

Flowing Entropy

X

X

X

Enthalpy (unit basis)

X

X

X

Latent Heat

X

X

Heat Capacity

X

X

Viscosity

X

X


X

X

Surface Tension

X

Critical Temperature

X

X

Critical Pressure

X

X

Critical Compressibility

X

X

API Gravity

X

X

Watson K Factor

X

X

Molar Average Boiling Point Temp.

X

X


April 2014

Plots Refer to Chapter 11, Printing and Plotting, for more information about generating graphical plots of Heating/Cooling Curve results.

Thermodynamic System You may select the thermodynamic system of methods to be used for heating/cooling curves calculations by choosing a method from the Thermodynamic System drop-down list box on the Heating/Cooling Curves main data entry window.

Mixer

General Information The Mixer unit combines two or more streams into a single product stream. The outlet pressure may be specified if desired. The outlet temperature and phase condition are always determined with an adiabatic flash from the feed conditions. This unit supports both VLE and VLLE calculations.

Feeds and Products The inlet pressure is assumed to be the lowest feed pressure. There is no limit on the number of feed streams to a mixer. Only one product stream is allowed for a mixer. PRO/II automatically sets the temperature and phase condition for the product. If phase separation of the product is desired, a separate flash unit must be used for this purpose.

Outlet Pressure Specification The pressure specification for the mixer product is selected with the appropriate radio button on the Mixer window: •

Pressure drop from feed conditions, or

•

Outlet pressure

If neither entry is supplied, the default is a pressure drop of zero.

Chapter 9


Thermodynamic System The thermodynamic system of methods to be used for mixer calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the Mixer main data entry window. This page intentionally is left blank.

Multivariable Controller

General Information The Multivariable Controller (MVC) is an expanded form of the Controller and simulates two or more feedback process controllers. The MVC is capable of adjusting an unlimited number of upstream variables to reach the same number of specified objectives. Each Specification may be a stream flow rate or property, a unit operating condition, or a Calculator result. The control variables may be stream and unit operation conditions, thermodynamic parameters, and Calculator results that are otherwise at fixed values in the flowsheet. For the Multivariable Controller, the number of variables must equal the number of specifications. The linked text above the Specifications grid in the Multivariable Controller main data entry window indicates whether the current number of specifications equals the number of variables. If they are unequal, the hypertext string “does not equal” will appear in red.

Specifications Establish the Specifications by clicking the appropriate linked text in the Specification grid of the Multivariable Controller window. MVC Specifications are established in the same manner as for the simple Controller Specifications. See the SPEC/VARY/DEFINE section of this chapter for further details on the generalized SPEC form.

Variables Establish the control variables (VARY’s) by clicking the linked text string Parameter in the Variable grid of the Multivariable Controller window. MVC VARY's are established in exactly the same manner as simple Controller VARY’s. See the SPEC/VARY/DEFINE section of this chapter for more information on the VARY concept. Tables are also given in that section listing the flowsheet variables that may be used for SPEC’s and VARY’s for multivariable controller units.


April 2014

Variable Limits and Step Sizes You may input limits for the each control variable, if desired. Variable limits and steps sizes for MVC are established in exactly the same manner as simple Controller limits and step sizes. In contrast to the simple Controller which has a default percent change of 2.0% of the initial control variable for the second iteration, the MVC has a default percent change of 10.0%.

Optional Variable Scaling Select the Use User-defined Variable Scaling check box on the Variable Limits window to enable a linear formula for scaling the variable. In order to access this window, click on the default limits linked text in the Variables field in the Multivariable Controller window. After you have enabled the Scaled Variable formula, the default limits linked text will change to read user-defined limits. Defaults for the scaled variable data are displayed on the Options window which can be accessed via MVC Options on the Multivariable Controller window. The same initial value, step sizes and tolerances are applied to all scaled parameters in the MVC. You may enter your own values here to replace the default values -5 100, 10, and 10 respectively.

Number of Calculation Cycles You may access several options for the operation of the MVC through the MVC Options button on the Multivariable Controller window. The default for the number of calculation cycles is calculated by the program as 18 plus the current number of variables. Alternatively, you may specify the number of cycles by selecting the appropriate radio button on the Options window. By default, the simulation will stop if any variable exceeds the maximum or minimum limits. You may select the Continue Calculations if Any Variable Exceeds the Limits check box to continue calculations using the limiting value if the limit is exceeded.

Select Next Unit Calculated After Control Variable is Updated Normally, the first unit operation in the calculation sequence affected by the control variable is the next unit calculated after the control variable is updated. Normally, the calculation sequence is determined automatically by PRO/II. However, you must supply a User-Defined Calculation Sequence whenever any of the control variables are thermodynamic parameters. You may specify the return unit by choosing a unit from the drop-down list box on the Options window.

Chapter 9


Print Results for Multivariable Controller The default is to suppress printing of a convergence report. The Print Options window allows you to override the default. This window is accessed by clicking Print Options on the Multivariable Controller window or be selecting Output/Report Format/Unit Operations from the menu. A convergence summary can be printed after the last cycle or after every cycle by selecting the appropriate radio button. Select the Include Convergence Diagnostics check box to generate a plot of the convergence diagnostics. Select the Include Convergence Diagnostics check box to generate a plot of the convergence diagnostics.

Non-convergence of Multivariable Controllers See the Controller section of this chapter for a discussion of convergence techniques used in the Multivariable Controller calculations.

Controllers and Recycle Loops See the Controller section of this chapter for a discussion of recycle loops. This page intentionally is left blank.

Phase Envelope

General Information The Phase Envelope utility module generates phase envelopes for multicomponent streams using the Soave-Redlich-Kwong or Peng-Robinson equations of state. The module is not available for other thermodynamic systems. Phase envelope generation is performed after the completion of flowsheet calculations and has no effect on flowsheet convergence. For systems with noncondensable gases such as hydrogen, helium, and nitrogen it may be impossible for the bubble point calculations to converge. The results should be reviewed carefully.

Selection of Streams You may select feed and product streams from any unit operation in the flowsheet for phase envelope generation. Up to five flowsheet streams may be selected using drop-down list boxes in the Phase Envelope main data entry window. You may optionally supply a liquid mole fraction for any of the selected flowsheet streams to generate a curve at a constant liquid mole fraction. This option is useful for generating liquid fraction curves to be superimposed on the


April 2014

phase envelope. Normally, you would first select a flowsheet stream with no liquid fraction entry to generate the phase envelope, followed by one or more selections with specified liquid fraction entries to generate a family of curves. It is not permissible to duplicate the same stream with the same liquid mole fraction in a single phase envelope.

Plot Options Select a plot option for the phase envelope in the Phase Envelope Plot Options window which you can access by clicking Plot Options on the Phase Envelope main data entry window. For each selected stream, a default descriptive label is provided in this window. The default label will contain the stream name and an L/F value if specified. You may modify each label. Duplicate labels are not allowed. An example default stream label with a specified L/F is: “S100 - L/F= 0.9". A drop-down list box contains plot options as follows: None - This is the default. No plots are generated. Individual - Individual generates a plot with only the stream selected. Comparison All streams with the Comparison option are plotted on the same graph. The Comparison option is useful for plotting a stream phase envelope with superimposed curves of constant liquid mole fraction. When you select the Comparison option for a stream, you will be prompted to provide a comparison plot symbol to label the data points for the generated curve. The symbol may be an integer number in the range one through nine. If you do not provide a symbol is not provided for the comparison plot, the next available integer between one and nine is used Individual and Comparison - The Individual and Comparison option performs both the Individual and Comparison options for a stream.

Thermodynamic System Select the thermodynamic system of methods to be used for Phase Envelope calculations by choosing a method from the Thermodynamic System drop-down list box on the Phase Envelope main data entry window.

PIPEPHASE Unit Operation

Chapter 9


General Information The PIPEPHASE Unit Operation (PPUOP) encapsulates a PIPEPHASE simulation enabling it to be solved in sequential modular form within a conventional PRO/II simulation. The PPUOP allows the user to link PRO/II simulation streams to PIPEPHASE simulations streams so that stream properties from a PRO/II simulation is passed to the PIPEPHASE simulation, and back to PRO/II upon solution of the PIPEPHASE simulation. As with any unit operation in PRO/II, the PPUOP can be accessed multiple times in calculation loops, and a PRO/II simulation can have multiple instances of PPUOP's in the flowsheet. The PPUOP is represented as an icon and is similar to other PRO/II unit operations. It can be initialized with a PIPEHASE simulation.

Note: Refer to the PRO/II Installation Notes for the specific versions of PIPEPHASE currently supported by PRO/II.

Feed and Product Streams The PIPEPHASE Unit Operation (PPUOP) can have multiple feed and product streams connected to it. The PRO/II feed streams are always mapped to the Sources in a PPUOP and the product streams are mapped to the Sinks in a PPUOP. The PPUOP Source can be specified with one feed stream only where as the Sink unit operation data can be mapped to multiple product streams. The stream properties that can be transferred through mapping are: Temperature, Pressure, Flow rate and Composition.

Component mapping Component mapping is allowed only if the number of components in both PRO/II and PIPEPHASE are equal. The components can be mapped by either Name or Index. These two options can be selected from the Component mapping dropdown list in the PRO/II PIPEPHASE window, which can be accessed by doubleclicking the PPUOP. If the components are mapped by Name, the PRO/II component data is mapped with the PIPEPHASE component of the same name. If the components are mapped by Index, then the first component in the PRO/II component data list is mapped with the first component of the PIPEPHASE component data list, irrespective of the component names.

Initialization The PPUOP can be initialized with a PIPEPHASE simulation (.inp for PIPEPHASE 8.2 and either an .inp or a .ppzip for PIPEPHASE 9.0) by clicking Initialize from PIPEPHASE simulation… in the PRO/II PIPEPHASE window. If the


April 2014

user reinitializes a PIPEPHASE simulation with another simulation, then all the information of the previous simulation will be removed. Note: When using PIPEPHASE version 8.2 files for initialization, it is necessary for the GUI database files, (.pp0 and .pp1) to be present. Otherwise, the user must generate the PIPEPHASE GUI database files by importing the corresponding keyword file.

PIPEPHASE GUI The PIPEPHASE GUI can be launched from within the PRO/II flowsheet. The user can commit the changes made to the simulation in the GUI, and export the changes to the keyword input file. The user can launch the PIPEPHASE GUI by clicking the PIPEPHASE GUI button in the PRO/II PIPEPHASE window. Note: The PIPEPHASE v8.2 requires the PIPEPHASE GUI files (.pp0 and .pp1) of the simulation. If not present, a warning message is displayed and the user is required to export the keyword file. However, for PIPEPHASE version 9.0, changes made in the PIPEPHASE GUI automatically are exported to the keyword file while saving the simulation.

Export The user can export a copy of the PIPEPHASE simulation to an external location by clicking Export to external PIPEPHASE simulation….

PIPEPHASE Reports The PIPEPHASE Report displays only the results of the PIPEPHASE simulation and not the PRO/II PIPEPHASE integration flowsheet. You can view the results of a solved PIPEPHASE simulation by clicking PIPEPHASE Report…button in the PRO/II PIPEPHASE window or right-click the PIPEPHASE icon and select View Results.

Stream link specifications A link between the PRO/II simulation and a PIPEPHASE simulation can be established on the Stream Link Specifications grid, in the PRO/II PIPEPHASE window. This window can be accessed by double-clicking the PPUOP icon. PRO/II streams that have been attached as feeds and products are displayed on the left side of the grid. PIPEPHASE Source streams are available on the dropdown lists on the right side, adjacent to PRO/II feed streams, and PIPEPHASE Sink streams are available on the drop-down lists on the right side, adjacent to the PRO/II product streams.

Chapter 9


Define Data link specifications The parameters of a PIPEPHASE unit operation can be specified as Spec/Vary/Define variables from within a PRO/II simulation to control either a PRO/II flowsheet or a PIPEPHASE network simulation. The Spec/Vary/Define variables can be specified in the Data Link specifications grid. This grid is available in the PRO/II PIPEPHASE window, which can be accessed by double-clicking the PPUOP. Check the option Define data link specifications to access the grid. For more details on these concepts, refer to the SPEC/VARY/DEFINE section of Chapter 9 in this manual.

File Handling When you drag and drop a new PPUOP on the PFD, and initialize it with a PIPEPHASE simulation, a copy of the PIPEPHASE file along with its database files is stored in the PRO/II Temp directory. This Temp folder is called the Managed folder and it will be the working directory for that specific PPUOP. All PIPEPHASE related files reside in this folder during the PRO/II simulation run. The files in the Managed folder are under the control of PRO/II and any changes made to these files by providing inputs through the PIPEPHASE GUI launched by clicking PIPEPHASE GUI… are saved to the files in the Managed folder and not to the PIPEPHASE database files in the original location. When PRO/II saves a set of simulation files, a new zip file is created by copying all the PIPEPHASE files from the Managed folder. These include all the PIPEHASE files (.inp, .pp0, .pp1, .out , and other intermediate files for PIPEHASE version 8.2, or ppzip for PIPEPHASE version 9.0) The .zip file name has the form “PRZfilename_UnitID.zip”, where “PRZfilename" is the simulation file name and “UnitID" is the ID of the PIPEPHASE unit in the simulation. This .zip file is archived in the PRO/II .prz, along with the conventional PRO/II (.pr1, .pr2, .sfd, etc.) files. This page intentionally is left blank.

Pipe

General Information The Pipe unit is used to model single or multiphase pressure drops in pipes and/or fittings which connect unit operations. This unit may be used in two


April 2014

modes: Rating Mode where the pressure drop is computed based on a specified line diameter, and Design Mode where the line diameter is calculated to meet a specified pressure drop and/ or velocity criteria. Numerous algorithms are provided for the pressure drop calculations to model a variety of piping applications. A rigorous heat balance may also be performed for the calculations, in which heat is transferred through the pipe to or from an ambient medium, or a duty is uniformly applied to the length of the pipe. The phase equilibrium is determined for the product and it may be separated into streams according to the phases. Both VLE and VLLE calculations are supported by this unit.

Feeds and Products A pipe operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. A pipe may have one or more product streams. The product phase condition for pipe operations with one product is automatically set by PRO/II. For pipe units with two or more product streams, the product phases must be specified in the Product Phases window which is accessed by clicking Product Phases… on the Pipe main data entry window. Allowed product phase declarations include: vapor, liquid, decanted water, heavy liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified. It is important to note that where two liquid phases are present in multiphase calculations, all pressure drop methods consider only a single liquid phase which has fluid properties that are an average of the properties for the two liquid phases.

Calculation Type The Calculation Type may be selected with the radio buttons provided on the Pipe main data entry window. Options are as follows: •

Fixed Line Diameter - Forward Calculation (default)

•

Fixed Line Diameter - Backward Calculation

•

Line Sizing - Forward Calculation

Backward calculations determine the pressure drop in a backward, or reverse, direction starting at the pipe outlet conditions. The pipe inlet conditions are defined by the results of the backward calculations. The line sizing option may be used for design mode, in which case the diameter of the pipe is determined to meet a specified design criterion. Note: Pipe calculations require liquid and vapor viscosities, and, for two phase flow, the liquid surface tension. Therefore, the thermodynamic system chosen for the calculations must provide these properties.

Chapter 9


Corrective Action for Calculation Failures The Continue text string on the Pipe main data entry window may be clicked to select the corrective action for certain types of calculation failures. The default option of Continue uses the best available solution or sets a negative computed outlet pressure to a small value and allows the flowsheet calculations to continue. For line sizing calculation failures, the line diameter which most closely satisfies the design criteria is selected and flowsheet calculations continue. A maximum of three consecutive failures is allowed for pipe units in recycle loops. The Stop option terminates all flowsheet calculations whenever the pipe unit fails to reach a solution, or a negative outlet pressure is encountered.

Pressure Drop Method Select the pressure drop method in the Pipe Pressure Drop Method window accessible via Pressure Drop Method… on the Pipe main data entry window. The pressure drop method is selected with the drop-down list box in this window, and includes the following methods: Beggs-Brill-Moody (BBM), Beggs-Brill-Moody with Palmer Correction (BBP), Olimens (OLIMENS), Dukler-Eaton-Flanigan (DEF), Mukherjee-Brill (MB), Gray (GRAY), and Hagedorn-Brown (HB). Beggs-Brill-Moody is selected as the default correlation. An optional estimated pressure drop may be supplied in this window to reduce the computing time. The convergence tolerance default of one percent and the default flow efficiency of 100 percent may be replaced in this window. The flow efficiency is a linear adjustment factor that is applied to the calculated pressure drop to better match actual conditions. The Moody friction factor for the pressure drop calculations may be supplied directly in this window, if desired. If no value is entered, the Moody friction factor is calculated using the modified Colebrook-White equations. The check box may be used to include or exclude the pressure drop contribution from acceleration. Under certain high velocity or high pressure drop conditions, this term becomes unrealistically high for the Beggs-Brill-Moody equation. Under these situations, excluding this term results in a more reasonable answer. Note: The Beggs-Brill-Moody equation does not cover critical flow.

Line/Fitting Data Line and fitting data are supplied in the Pipe Line/Fitting Data window which is reached by clicking Line/Fitting Data on the Pipe main data entry window. For fixed line diameter calculations, radio buttons on this window are used to select


April 2014

the input mode for the pipe diameter. When the Inside Diameter radio button is selected, the pipe inside diameter is supplied directly. When the Nominal Pipe Size radio button is selected, a drop-down list box is used to select the desired pipe nominal diameter from a table of common pipe sizes. For this option, the pipe schedule may also be chosen with a drop-down list box. When no schedule is chosen, schedule 40 pipe is assumed in most cases. The line length is supplied directly in this window. The maximum allowable line length is 900,000 feet (274,000 meters). An elevation change over the line length may be entered in the Pipe Line/Fitting Data window. A plus value indicates an increase in elevation; a minus sign indicates a decrease in elevation. The absolute value of the elevation change must not exceed the line length. One fitting K-factor may be attached to a pipe unit and supplied in this window. The K-factor is defined as the total resistance coefficient, and is limited to a maximum value of 100.0. Note that the supplied K-factor may be used to represent multiple fittings, valves, and exit losses. When a pipe unit is being used to represent a fitting or fittings only, a negligible line length should be provided. Radio buttons are used to select the pipe roughness in this window. The Absolute roughness may be entered in length units or the Relative roughness may be supplied. The roughness applies to both the line and the fitting. A default absolute roughness of 0.0018 inches or equivalent (new steel pipe) is used when no roughness is supplied. The number of calculation segments is selected by clicking the text string at the bottom of this window. A maximum of 50 segments may be used. The pressure drop calculations are based on the average fluid properties in a segment; therefore, it is important to use multiple segments for systems in which the fluid properties vary significantly over the line length (such as multiphase systems). The number of calculation segments has a significant effect on the calculated pressure drop for such systems. It is also recommended that long lines be divided into segments of 10,000 feet (3040 meters) or less. Note that a default of one segment is used for a pipe unit unless otherwise specified. Note: When line sizing calculations are performed, the line/fitting diameter and fitting K-factor cannot be supplied, and these data entry fields are not available.

Line Sizing Data Line sizing data are supplied in the Pipe Line Sizing window which is accessed by clicking Line Sizing Data on the Pipe main data entry window. Primary sizing criterion options are: •

Maximum Pressure Drop

Chapter 9


•

Minimum Outlet Pressure

Values for the maximum pressure drop or the minimum outlet pressure are supplied directly in the data entry fields provided. A Maximum Average Fluid Velocity constraint may also be defined. This constraint can not be violated, and the primary sizing criterion will be relaxed as needed to not exceed the supplied maximum velocity. The Line Inside Diameter Selection Method is chosen with radio buttons as follows: •

Use Explicitly-defined Inside Diameters

•

Use Nominal Pipe Sizes

A default inside pipe diameter table with ten diameters is provided. The default values may be replaced as desired. Use Clear All to clear the pipe diameter table. The Restore Defaults button restores the ten default diameters. A table of nominal pipe sizes and corresponding schedule numbers may be supplied in the Nominal Pipe Sizes window which is reached by clicking Enter Data… on the Pipe Line Sizing window. Up to ten pairs of data may be provided. Nominal pipe sizes are selected from a table of supplied values via drop-down list boxes. The corresponding schedule numbers are also selected via drop-down list boxes. Pipe schedule numbers default to schedule 40 in most cases. The Clear All button may be used to clear all selected nominal pipe sizes and corresponding schedules.

Heat Transfer Data Heat transfer data are supplied on the Pipe Heat Transfer window accessible via the Heat Transfer icon on the Pipe main data entry window. The duty calculation option is selected via radio buttons: •

Fixed Duty

•

Ambient Heat Transfer

•

Isothermal Operation

For Fixed Duty calculations, the supplied duty is applied evenly over the entire length of the line. A positive value is used for heating and a negative value signifies cooling. This option with a duty of zero is used as the heat transfer default option. This option may be used for both forward and backward calculations. An overall U factor and ambient temperature must be provided for the Ambient Heat Transfer option. The U factor has units of energy/ (area)(time)(degree). A


April 2014

default value of 6°F is used for the ambient temperature. The heat transfer is computed from the pipe segment inlet and outlet temperatures, U factor, pipe inside area, and the ambient temperature. This option may not be used with backward calculations. The Isothermal Operation option performs all pressure drop calculations at the inlet temperature to the pipe unit. This option is not allowed for backward calculations.

Thermodynamic System The thermodynamic system for the pipe calculations may be selected with the drop-down list box on the Pipe main data entry window. The problem Default system is used when no other thermodynamic system is selected. This page intentionally is left blank.

Polymer Reactor

General Information The Polymer Reactor model simulates either a free radical or stepwise polymerization process in an ideal Continuous Stirred Tank Reactor (CSTR) or Plug Flow Reactor (PFR). The polymerization reactions are assumed to take place in the liquid phase and the system is assumed to be homogeneous. The reactors may be run in the isothermal or non-isothermal modes and the operating pressure may be set. The Polymer Reactor calculation model allows for up to 79 different reaction mechanisms to be used in copolymer free radical kinetics. Not all are intended to be used simultaneously; in fact, the fewer mechanisms specified for the polymer system, the more realistic and reliable the model. It is assumed that the polymerization reactions occur in the liquid phase. If the reaction leads to a two phase situation, a warning message is given and the user must then specify new operating conditions to keep the system in the one phase region. The CSTR mass and energy balances are solved to identify a single stable operating point. The polymer which exists at this operating condition is then characterized in terms of the method of moments to provide number and weight average molecular weights.

Chapter 9


The PFR mass and energy balances are solved to identify a sequence of stable operating points along the axial dimension. The polymer which exists at each point along the axial profile is then characterized in terms of the method of moments to provide number and weight average molecular weights. The user must supply the feed component temperature, pressure, and composition along with an estimate of the temperature of the isothermal reactor or a temperature estimate for the non-isothermal reactor. Kinetic and thermodynamic data for the reaction between chemical species must also be provided.

Detailed Information For detailed information regarding operating modes, data requirements, and range of applicability of the Polymer Reactor model, consult the PRO/II Add-On Modules User Guide.

Procedure Data General Information Procedures provide a way to calculate the reaction rate based on a user’s own calculation method. The reaction rate calculation is required by the plug, CSTR, reactive distillation and batch reactor units. PRO/II’s default method for reaction rate calculation is based on power law rate expressions. For any other rate, expression type (such as Langmuir-Hishelwood) or any reaction rate which deviates from the base rate (such as a reaction with a mass transfer limitation), Procedures and the alternative User-Added Kinetic Subroutines (see PRO/II User-Added Subroutines User Guide) can be used to calculate the proper rate for reactor simulations. Procedures are essentially in line routines written in a language based on FORTRAN 77. There are two sections to a Procedure: Setup and Code. The setup section allows for the definition of each Procedure’s name, description, variables and parameters. The code section is where all calculations are performed. This section resembles a subroutine written in a FORTRAN-like language.

Procedure Setup Use the Procedure Data dialog to enter procedure data. Access the dialog window through the Input/Procedure Data… menu option, or by clicking the . Each Procedure in this window has a Procedure Data toolbar button mandatory name and an optional description. As soon as the name for a Procedure is entered, the Enter Data… button becomes available. The button opens the Kinetic Procedure Definition window where you may click Edit/View Declaration to access the Declarations of variables and parameters.


April 2014



Any variable names entered in Defined Procedure Variables will be available to transfer information from the reactor unit to the Procedures it calls. They can be DEFINE'd in the reactor unit, and accessed in the same manner as any other variable in the Procedure code.



There is only one Parameter available to be specified, which is the maximum number of reactions allowed. This only needs be changed if the Procedure must handle more than the default of 15 reactions.

After completing the setup, click Hide Declaration to close the Declarations dialog.

Procedure Code Note: The Procedure Code section is required and must terminate with a RETURN statement. The actual FORTRAN procedure is entered directly in the Code field on the Kinetic Procedure Definition data entry window. You may check the procedure as you compose it by clicking Check Code. The following predefined variables are provided from the calling reactor unit: 

Kinetic data: These are the kinetic parameters are provided via K… of the Reaction Data section, and/or Unit Reaction Definitions… of the Reactor unit.



Reactor data: These data include the reactor sizing parameters and operating conditions.



Property data: These data include the thermo-physical property data of the pure components (e.g., molecular weight or critical pressure), and the property data of the individual components and mixture at the reaction conditions.



User data: These are the integer, real, and supplemental data provided by the user via Enter Data… when the procedure name is specified for rate calculations for a Reactor unit.



Procedure data: These are the defined procedure variables entered during the Procedure setup. Their values are DEFINE’d in the same window as the User data.

The supported language features are discussed below.

Elements of the Language Each statement contains a maximum of 80 characters. An ampersand (&) at the end of a line indicates continuation on the following line. Note that an asterisk (*) is not valid as a continuation marker, since it signifies multiplication.

Chapter 9


All lines of code except the CODE statement may be preceded by a unique numeric label from 1 to 99999 (shown as “nn” in this manual). A dollar sign (“$”) causes all following data on the line to be interpreted as a comment rather than as code. Unlike in FORTRAN, a “C” in column 1 does not designate a comment statement.

Predefined Variables The following variable names are reserved. They are used to pass values between the procedure and the unit operation that uses the procedure. The first tables list variables that provide input values to the procedure. They may not appear on the left side of an assignment statement. Procedure Data Predefined REAL Scalar Variables Property

Variable Name

PFR

CSTR

Batch

RxDist

REAL Scalar Variables - Supplied in standard problem dimensional units Temperature

RTEMP

X

X

X

X

Pressure

RPRES

X

X

X

X

Total Molecular weight

RMW

X

X

X

X

Vapor Phase

RVMW

X

Liquid Phase

RLMW

X

L1 Phase

RL1MW

X

L2 Phase

RL2MW

X

Specific gravity (60/60)

RSPGR

X

X

X

X

Total Molar Rate

RMRATE

X

X

X

X

Vapor Phase

RVMRAT

X

Liquid Phase

RLMRAT

X

L1 Phase

RL1MRA

X

L2 Phase

RL2MRA

X

Weight Rate

RWRATE

X

X

X

Standard Volumetric 2 Rate

RSVRAT

X

X

X

Actual Volumetric Rate

RAVRAT

X

X

X

Vapor Phase

RVVRAT


X

X

April 2014

Procedure Data Predefined REAL Scalar Variables Property

Variable Name

PFR

CSTR

Batch

RxDist

Liquid Phase

RLVRAT

X

L1 Phase

RL1VRA

X

L2 Phase

RL2VRA

X

Liquid Fraction

RLFRAC

L1 Phase

RL1FRA

X

L2 Phase

RL2FRA

X

Vapor Phase Viscosity

RVVISC

X

X

X

X

Liquid Phase Viscosity

RLVISC

X

X

X

X

X

X

X

X

REAL Scalar Variables - Supplied in standard problem dimensional units Vapor Phase Conductivity

RVCOND

X

X

X

X

Liquid Phase Conductivity

RLCOND

X

X

X

X

Vapor Phase Sp. heat

RVCP

X

X

X

X

Liquid Phase Sp. heat

RLCP

X

X

X

X

Surface tension

RSURF

X

X

X

X

Absolute Temperature

RTABS

X

X

X

X

Tube Diameter (fine length)

TDIAM

X

Tube Length

TLEN X

X

Cumulative Length

CUMLEN

X

Plug Flow Step Size (fine length)

DELX

X

Total reactor volume (CSTR & BATCH) or volume step size of PLUGFLOW reactor

VOLUME

X

X

X

Vapor Phase Volume

RVVOLU

Chapter 9

X


Procedure Data Predefined REAL Scalar Variables Property

Variable Name

PFR

CSTR

Batch

RxDist

Liquid Phase Volume

RLVOLU

X

L1 Phase Volume

RL1VOL

X

L2 Phase Volume

RL2VOL

X

Gas Constant

RGAS

X

X

X

X

1 Volumetric flow rates for CSTR and PLUGFLOW are calculated using bulk compositions assuming the specified reactor phase, even if the phase is actually mixed. A warning is printed if the actual phase is mixed. 2 Standard vapor volume conditions are different from liquid mole volume standard conditions. Refer to Table 1: Standard Conditions on page 47.

Procedure Data Predefined INTEGER Scalar Variables Property

Variable Name

PFR

CSTR

Batch

RxDist

Total # of components

NOC

X

X

X

X

Total # of reactions

NOR

X

X

X

X

Reaction phase

IRPHAS

X

X

X

Basis for Rate Calculation 0 = molar 1 = partial pressure 2 = fugacity 3 = mole-gamma

ICPFA

X

X

X

Step #

ISTEP

X

Unit # for output file

IOUT

X

X

X

X

Unit # for index file

INDX

X

X

X

X

Maximum # of reactions

MAXNOR

X

X

X

X


April 2014

Procedure Data Predefined REAL Variable Arrays Property

Variable Name

PFR

CSTR

Batch

RxDist

X

Dimension : NOC Total Molar Composition

XTOTAL

X

X

X

Total Molar Concentration

XCONC

X

X

X

Vapor Phase

XVCONC

X

Liquid Phase

XLCONC

X

L1 Phase

XL1CON

X

L2 Phase

XL2CON

X X

X

X

X

Vapor Phase Fugacity

XVFUG

Liquid Phase Fugacity

XLFUG

X

L1 Phase

XL1FUG

X

L2 Phase

XL2FUG

X

XLACT

X

L1 Phase

XL1ACT

X

L2 Phase

XL2ACT

X

Liquid Phase Activity

Vapor phase Mole Fractions

XVAP

X

X

X

X

Liquid phase Mole Fractions

XLIQ

X

X

X

X

L1 Phase

XLIQ1

X

L2 Phase

XLIQ2

X

Vapor phase Mass Fractions

XVMFRA

X

Liquid phase Mass Fractions

XLMFRA

X

L1 Phase

XL1MFR

X

L2 Phase

XL2MFR

X

Dimension: 70 Real

Chapter 9

RDATA

X

X

X

X


Procedure Data Predefined REAL Variable Arrays Property

Variable Name

PFR

CSTR

Batch

RxDist

numbers supplied on RDATA statement Dimension: 200 Real numbers supplied on SUPPLE statement

SUPPLE

X

X

X

X

Dimension: NOR Activation Energy* Pre-exponential factor Temperature Exponent

ACTIVE PREEXP TEXPON

X X X

X X X

X X X

X X X

Dimension: (NOC,NOR) Stoichiometric factor Reaction order

STOICH ORDER

X X

X X

X X

X X

* There is an important distinction between the values of activation energy for in line procedures and calculations involving local reaction sets in distillation columns or reactors. The values of activation energy supplied the reference reaction set (in RXDATA) or in the local reaction sets are assumed to be in thousands of energy units per mole units, whereas, in the case of procedures, the user-supplied value is used without the above assumption. E.g., for the SI system, a value of ACTIV=123 kJ/kmol in the RXDATA or local rxnset is used as 123,000 kJ/kmol in calculations. A procedure using the same variable, say ACTIV(1), would calculate based on a value of 123 kJ/kmol. Procedure Data Predefined INTEGER Variable Arrays Variable Name Dimension: 10 Integer supplied on IDATA statement Dimension: NOR Base Component Calculation basis for each reaction rate (liquid phase)


PFR

CSTR

Batch

RxDist

IDATA

X

X

X

X

IDBASE

X

X

X

X

ILBASI

1

X

April 2014

0 = molar 1 = partial pressure 2 = fugacity 3 = mole-gamma 4 = mole fraction 5 = mass fraction Calculation basis for each reaction rrate (vapor phase) 0 = molar 1 = partial pressure 2 = fugacity 3= mole-gamma 4 = mole fraction 5 = mass fraction Dimension: (NOC,NOR) Phase of components in rxn 1 = Vapor 2 = Liquid

1

X

IVBASI

X

IPHASE

1

Available only for Boiling Pot CSTR

The following variables are the PROCEDURE block results available to PRO/II after control is returned to the PLUGFLOW, CSTR or Reactive Distillation unit operation. RRATES must be defined for all reactions. PROCEDURE Results Variable Name Values of solution flag: 0 Default value. Assumes the PROCEDURE step has solved. 1 PROCEDURE solved. 2 PROCEDURE failed; continue calculations if in a recycle or control loop. 3 PROCEDURE failed,

Chapter 9

PFR

CSTR

Batch

RxDist

X

X

X

X


stop all flowsheet calculations. Reaction rates for each reaction moles/ (liqvol* time) for OPERATION 1 PHASE=L , moles/(vapvol*time) for OPERATION 1 PHASE=V Temperature derivatives for each reaction Composition derivatives for each reaction

RRATES (NOR)

X

X

DRDT 2 (NOR) DRDX (NOC, 2 NOR)

X

X

X X

1 CSTR and PLUGFLOW should not be used when multiphase reactions are expected. Except for Reactive Distillation and the CSTR boiling pot model, PRO/II assumes the phase is 100% liquid or vapor as defined on the OPERATION statement. 2 The use of this is optional.

Procedure Data Programming Language See the discussion of the Calculator module at the beginning of this chapter for a survey of the proper use of Declaration Statements, Assignment Statements, Fortran Intrinsic Functions, PRO/II Intrinsic Functions, IF Statements, Calculation Flow Control Statements , and Calculation Termination Statements ).

Pump

General Information The Pump may be used to compute the energy required to increase the pressure of a process stream. This quantity of energy is added to the feed enthalpy to determine the outlet temperature. Only the bulk liquid phase is considered in the calculations.


April 2014

Feeds and Products A pump operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. A single liquid product stream is allowed from a pump.

Specifications Outlet Conditions The Pressure Specification for a pump is selected with the appropriate radio button on the Pump main data entry window as: •

Outlet pressure

•

Pressure rise (” P)

•

Pressure ratio based on the lowest feed stream pressure.

Pump Efficiency A pumping efficiency in percent may be supplied in the data entry field provided on the Pump main data entry window. This value is used for the work and outlet temperature calculations. If not supplied, a default value of 100 percent is used.

Thermodynamic System The thermodynamic system of methods to be used for pump calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the Pump main data entry window.

Reaction Data General Information Use the Reaction Data Sets data entry window to supply reaction stoichiometry, heat of reaction, kinetic and equilibrium data, and to specify the base component for each reaction. One or more reactions may be saved as separate reaction data sets and used in all reactor types (conversion, equilibrium, Gibbs free energy minimization, plug flow, CSTR, and boiling pot reactors). Multiple unit operations can have common access to the same reaction data. The PRO/II graphical user interface now supports multiple equilibrium expressions for each Equilibrium Reactor. Note: You may specify the base component of the reaction and provide heat of reaction and equilibrium and kinetic data in the Reactor data entry window. For conversion reactors, these data are considered to be local

Chapter 9


and are entered at the unit operation level. See the Reactor section later in this chapter.

To access the Reaction Data window: 

Click Reaction Data

on the main toolbar.

Note: Any data entered in the Reaction Data window is passed to the Unit Reaction Definitions dialog (a sub-window of the main Reactor window) and used as default values.

Specifying Reaction Sets Provide a name and description for each reaction data set in the main Reaction Data window. The name is required but the description is optional. Note: You must define the component list in the Component Selection data entry window before entering reaction data. This order is important because components for each reaction must be selected from a previously-defined component list. To enter data for each newly-defined reaction data set, or to modify the data for imported sets: 

Click Enter Data… for that set.

This opens the Reaction Definitions window for that set. Here, you may enter the following information for the reaction data set: •

Kinetic rate calculation method

•

The name of all reactions in the set (required)

•

The reaction stoichiometry (required)

•

The heat of reaction and the base component (required)

•

Equilibrium data (optional)

•

Kinetic data (optional).

To select the kinetic rate calculation method: The kinetic rate can be calculated from PRO/II’s reaction rate subroutine based on the power law rate expression, by an inline procedure or by the user’s kinetic subroutine. The inline procedure must be first defined in the Procedure Data section and selected from the Procedure Name drop-down list box. When a useradded kinetic subroutine is used, it can be selected from the Subroutine Name drop-down list box. The user’s added kinetic subroutine must be named as one of the five USKIN1, USKIN2, USKIN3, USKIN4 and USKIN5 routines and linked to PRO/II as described in the PRO/II UAS/PDTS Installation Guide.


April 2014

To define the stoichiometry: Define the reaction stoichiometry by clicking on the linked text Reactants = Products in the Definition column to open the Reaction Components window. Here, you may select the reactants and products for the reaction and supply the stoichiometric coefficient for each. You may define the reaction based on the chemical formula of the component (library components only), or based on the name (for library, non-library, or petro components). To define the heat of reaction: You may define the heat of reaction for any selected reaction in a specific reaction data set, in the Heat of Reaction Data window. This window appears when you click H… located beside the selected reaction on the Reaction Definitions window. In this window, you may choose one of two options: Calculated from Heat of Formation: This option allows PRO/II to calculate the heat of reaction based on the heats of formation for the reaction components. This is the default. User-specified: You supply the heat of reaction (in units of energy/ weight). If you do so, you may also optionally supply the reference temperature, component, and reference reaction phase. Note: You must supply heat of reaction data for non-library components that do not have heat of formation data. You must also specify the base component for the reaction. To supply equilibrium data for a specific reaction in a reaction data set: 

Click E… located beside the selected reaction in the Reaction Definitions window. The Reaction Equilibrium Data window appears.



Click the Define Equilibrium Data check box to enter equilibrium data.

You may supply the following data in this window:

Equilibrium Coefficients: Up to 8 (A-H) coefficients for the equilibrium equation (at least one coefficient must be supplied). Units: Temperature, weight, volume and pressure units of measure for the equilibrium data may be supplied by clicking on the linked (underlined) text in the Units box. (If you do not change the temperature units, the global units are used by default). Equilibrium Constant Expression: The default reaction phase, reaction activity bases for vapor and liquid phases, component reaction phases, and exponent orders can be entered here. Click Activity Exponent and Activity Phase to specify the exponent order and activity phase for each

Chapter 9


component in the reaction. The vapor activity basis is used for all components specified with vapor phase activity phase while the liquid activity basis is used for all components specified with liquid phase activity phase. To supply kinetic data for a specific reaction in a reaction data set: 

Click K… located beside the selected reaction in the Reaction Definitions window. The Reaction Kinetic Data window appears.



Click the Define Kinetic Data check box to enter kinetic data.

You may supply the following data in this window: Pre-exponential Factor (A): The pre-exponential factor of the power law kinetic rate equation for the reaction. The default is 1.0. Activation Energy: The activation energy of the power law kinetic rate equation for the reaction in units of energy/weight. A default of zero is used if a value is not supplied. Temperature Exponent: The temperature exponent of the power law kinetic rate

equation for the reaction. A default of zero is used if a value is not supplied. Reaction Order and Activity Basis: The data declared using this option include: the default reaction phase, reaction activity bases for vapor phase, liquid phase, component reaction phase and kinetic orders that define the kinetic rate expression. Click Reaction Order and Activity Phase to specify the kinetic reaction order and activity phase for each component, which appeared in the rate expression. The vapor activity basis is used with all components specified with vapor activity phase while the liquid activity basis is used with all components specified with liquid activity phase.

Reactor General Information The Reactor unit operation simulates the operation of many chemical reactors including conversion reactors, equilibrium reactors, Gibbs (Free Energy Minimization) reactors, Plug Flow Reactors (PFR’s), Continuous Stirred Tank Reactors (CSTR’s), and Boiling Pot Reactors. In addition to the above reactor types, PRO/II contains built-in Shift and Methanation reaction data sets for either conversion or equilibrium reactors.


April 2014

Feeds and Products Each reactor may have one or more feed streams. A multiphase product from the reactor may be separated into streams containing one or more phase. The allowable product stream phases are vapor, liquid, decanted water and mixed (vapor + liquid). A mixed phase product is not allowed with a vapor or a liquid product. The decanted water product is also used as the second liquid product phase with rigorous VLLE calculations. If this is more than one product stream, the phases must be allocated to the streams in the Product Phases window. Access this window by clicking Product Phases… on the main Reactor data entry window for the particular reactor type.

Reactor Type For conversion, equilibrium, Gibbs, or plug flow reactors, select the reactor type by choosing the appropriate reactor icon from the PFD palette. CSTR and boiling pot reactors share the CST/Boiling Pot Reactors icon. Select the desired reactor type from a drop-down list box on the main Reactor data entry window.

Reaction Set For all reactor types other than the Gibbs reactor, you must select a reaction data set from the Reaction Set Name drop-down list box (options include a built-in reaction set, e.g., Shift reaction, or a user-defined set) on the Reactor main data entry window. For the Gibbs reactor type, either no reaction data set may be selected (option None), or a user-defined set may be specified. See the Reaction Data section, earlier in this chapter, for more information on specifying reaction data sets.

Thermal Specifications For most reactor types, the fixed operating temperature, the temperature rise across the reactor, or the fixed reactor duty may be specified by using radio buttons and entering values in the appropriate data fields. The available options are: Temperature Rise: This is the temperature increase across the reactor. This option is available for conversion and equilibrium reactors only where it is the default. Combined Feed Temperature: Enter the average temperature for all feed streams to the reactor. This is available for plug flow and Gibbs reactors, and CSTR's only where it is the default. Fixed Temperature: You may specify the final reactor temperature for all reactor types.

Chapter 9


Fixed Duty: You may specify the reactor duty for all reactor types. A default value of 0 will be used if a value is not specified. The following additional reactor information may also be given via the main Reactor window: External Heat: You may specify information on the external heating or cooling source by selecting the External Heat option. This is for plug flow reactors only. Click Enter Data… and enter data in the External Heating/Cooling window. Temperature Profile: You may enter the reactor temperature profile in tabular form as a function of the actual reactor length, or as a function of percent or fractional distance along the reactor. This is for plug flow reactors only.

Reactor Data Click Reactor Data… from the main Reactor data entry window to open the Reactor Data window where you can supply reactor configuration information.

Conversion and Equilibrium Reactors

For these reactor types, you may choose an error handling option by clicking the Stop calculations hypertext. The options are: Stop Calculations: This stops calculations if an error occurs (e.g., for negative component flows). This is the default. Continue Calculations with no Reaction: Continue calculations with no reaction if an error occurs. Add Makeup of Limiting Reactant: Reduce conversion by adding a makeup of the limiting reactant if an error occurs. Reduce Conversion: Reduce conversion if an error occurs.

Continuous Stirred Tank Reactor

You must provide the reactor volume for CSTR’s in the Reactor Data window. Optionally, you may also provide estimates of the product flow rate.


April 2014

Plug Flow Reactor

Enter the following data for PFR’s in the Reactor Data window: Reactor Length: The total length of the reactor. Data for this field is mandatory. Tube Inside Diameter: The inside diameter of the PFR tubes. Data for this field is mandatory. Number of Tubes: The total number of tubes in the PFR. Default is 1. Number of Points for Profile: The number of equidistant locations along the reactor length for the temperature profile. Default is 10. Integration Options: You may select one of four integration options: •

Fixed step size Runge-Kutta method. The Runge-Kutta method with 20 steps is the default.

•

Runge-Kutta method with user-specified step size.

•

Gear integration method with user-specified gear tolerance (default tolerance = 0.1%).

•

LSODA (Livermore Solver of Ordinary Differential Algebraic equations) method with user-specified tolerance (default tolerance = 0.1%).

Enter the following data for PFR’s in the Pressure window:

Select between the two options listed for Reactor Type •

Open Pipe: Select this option, when the packing is not found in PFR.

•

Packed Pipe: Select this option, when the PFR is packed with catalyst particles.

Select an appropriate option from the list to enter the pressure specification •

Inlet and Outlet Pressure

•

Pressure Profile

•

Pressure Drop Method

•

Packed Bed Pressure Drop

Chapter 9


If you have selected Open Pipe under Reactor Type, the first three options mentioned above will be made available to the user. If you have selected Packed Pipe under Reactor Type, except Pressure Drop Method all other options will be made available to the user. Inlet and Outlet Pressure: Selecting this option will enable the Inlet and Outlet section. User is prompted to enter data listed under the following section. •

Inlet

•

Outlet

Pressure Profile: Selecting this option will enable the Enter Data button. Click Enter Data to open the Pressure Profile dialog box. Select the appropriate Location option from the drop-down list and start entering the data for Location and Pressure. •

Actual Tube Length

•

Percentage of Tube Length

•

Fraction of Tube Length

If you have selected Open Pipe in the Reactor Type section, Pressure Drop Method will be made available for selection. In case you have selected Packed Pipe in the Reactor Type section, Packed Bed Pressure Drop will be made available for selection. Pressure Drop Method: Selecting this option will enable the Enter Data button. Click on it to open the Pressure Drop Method dialog box. Pressure Drop Correlation: Select the appropriate pressure drop method listed in the drop list. Pressure Drop Correlation

Significance

Beggs-Brill-Moody

This is the default PRO/II method, and is the recommended method for most systems, especially single phase systems.

Olimens

Used for gas condensate systems, which uses the Eaton correlation to calculate liquid holdup and Moody diagrams for friction factor.

Dukler-Eaton-Flanigan

This hybrid correlation is for gas condensate systems that are mainly gas.

Gray

Recommended for vertical gas condensate


April 2014

systems. It is not suitable for horizontal lines. Hagedorn-Brown

This method also is recommended for vertical pipe lines, and should not be used for horizontal pipes.

Mukherjee-Brill

Used for gas condensate systems. This method must be used with care due to its discontinuities. Use at least 2 pipe segments to avoid failures due to changing flow regimes.

Beggs-Brill-Moody-Palmer

This is the same as Beggs-Brill-Moody, but also includes the Palmer modification to account for liquid holdup, based on experimental data for uphill and downhill lines.

Convergence Tolerance: Supplies a relative convergence tolerance value for the calculated pressure drop per reactor segment. The tolerance applies to changes between successive iterations. By default, PRO/II uses a one percent tolerance. Flow Efficiency: This parameter is used for linear adjustment of the calculated pressure drop to match actual conditions. For given flow conditions, decreasing this value causes an increase in the calculated pressure drop. The value may be greater than 100 percent. It is recommended that data for roughness or Moody friction factor be provided for accurate calibration of results. Moody Friction Factor: PRO/II usually calculates the friction factor from reactor roughness and Reynolds number using the modified Colebrook-White equations. You can supply a value for this field if desired. Roughness: A roughness value can be supplied either in Absolute or Relative units. By default, PRO/II supplies an absolute roughness of 0.0018 inch. Acceleration Term: Check this option to include the acceleration pressure gradient. Under certain high velocity or high pressure conditions, the Beggs and Brill acceleration term becomes unrealistically large and dominates the equation. Dropping the term often results in a better answer in these cases. Packed Bed Pressure Drop: Selecting this option will enable the Enter Data button. Click Enter Data to open the Packed Bed Pressure Drop Method dialog box. Pressure Drop Correlation: Select Ergun Equation to calculate the pressure drop across the packed bed. Diameter of Catalyst: Enter the diameter of the catalyst. Data for this field is mandatory.

Chapter 9


Void Fraction of the Packed Bed: Enter the Void fraction of the packed bed. Data for this field is mandatory. Under Shape Factor section, enter data for the shape of the catalyst. Select either of the two options depending on the catalyst. Sphericity: Enter the sphericity of the catalyst. Shape of the Catalyst: Selecting this option will make the following option available to the user. Select either of the two options. •

Spherical

•

Cylindrical: If you have selected Cylindrical, enter the Length.

Boiling Pot Reactor

You may supply the following reactor calculation options for the boiling pot reactor in the Reactor Data window: Tolerances: The absolute temperature and relative mole fraction and enthalpy tolerances for the reactor may be changed from their default values of -5 -4 0.1º, 10 , and 10 respectively. Note: If the Fixed Duty option is specified on the main Reactor data entry window, an estimate of the reactor temperature may optionally be provided in the Reactor Data window. The minimum and maximum temperature defaults of - 457.87 F and 4940.33 F may also be overridden. Maximum Liquid Volume: If a fixed volume is not supplied on the main Reactor window, you may supply a maximum liquid reactor volume in this 3 window. A default of 3531.5 ft will be used if a value is not provided. Initial Volume Estimate: An initial volume estimate may optionally be supplied in this window. Component product rate estimates may also be supplied by clicking Product Estimates… on the Reactor Data window. The number of Broyden trials before the Jacobian matrix is updated may be specified along with the derivative step size multiplier by clicking on the appropriate underlined linked text. The defaults are 3 trials and a step size multiplier of 0.01.


April 2014

Gibbs Reactor

For the Gibbs reactor, the user may provide a number of optional calculation options in the Reactor Data window: Maximum Iterations: The maximum number of iterations allowed. The default is 50. Convergence Tolerance: The relative convergence tolerance. The -4 -6 default is 10 for isothermal conditions and 10 for adiabatic conditions. Fibonacci Tolerance: The convergence tolerance for the Fibonacci search calculations. The default is 0.01. In addition, you may specify the physical property evaluation method by clicking on the underlined hypertext. The options are: Evaluated at each step: This is the default setting. It evaluates physical property values at each step of the search. This is the default. Used from previous iteration: The physical property values from the previous iteration are used. You may select the product rate estimate option by clicking on the underlined linked text. The available options are: PRO/II default: The default generates an initial estimate of the product rates using the PRO/II method. Average of all feeds: This uses the average of all feed rates to generate an initial product rate estimate. Supplied reacting component rates: This option instructs the algorithm to use the user-supplied values instead of calculating its own rate estimates for the reacting components. Supply reacting components and estimated rates in the Reacting Components window, which is reached by clicking Reacting Components and Estimates on the Reactor Data window. The options to specify the parameters for the free energy minimization phase calculations are found in the Phase Split Parameters window. This opens by clicking Phase Split Parameters on the Reactor Data window. Note: The Phase Split Parameters window is available only if the Reactor Operation Phase is specified as Calculated on the Unit Reaction Definitions window. See below for Unit Reaction Definitions.

Chapter 9


Specfying Reactions: The number of chemical reactions (i.e., the number of REACTION statements) must equal the number of chemical species minus the number of effective atoms. Usually, the number of effective atoms is the number of atomic species.. The number of effective atoms differs from the number of atomic species when two or more atoms always occur together in the same proportion. For example, consider the chlorination of ethylene: Keq

C 2 H 4 + Cl 2 ⇔ C 2 H 4 + Cl 2 There are 3 atomic species (C, H, Cl), but C and H always occur in a 1:2 ratio. Therefore, the number of effective atoms is 2 (Cl and CH2). These two effective atoms represent the three chemical species, so only one chemical reaction is allowed. The options available on the Phase Split Parameters window are: Initial Phase Estimate: This entry is the phase used for the initial reactor calculations. The user may select the vapor, liquid, vapor–liquid, liquid– liquid, or vapor–liquid–liquid phase. The default is vapor–liquid. First Phase Evaluation at Iteration: Specify the first iteration where the phase will be reevaluated. The phase should not be evaluated too early because the reaction results may still be far from the final solution. The default is 6. Phase Evaluation Frequency: Specify the number of iterations between phase evaluations. The default is 4. Minimum Phase Tolerance: When the molar ratio of a phase to the total quantity of material is less than this value, the phase is considered as -6 non-existent. The default is 10 . Atomic groups can be provided in the Atomic Groups window. This window can be reached by clicking the User-specified Atomic Groups button on the Reactor Data window.

Unit Reaction Definitions The reaction phase, heat of reaction, equilibrium data, and kinetic data for the reactor may be entered in the Unit Reaction Definitions window. Bring up this window by clicking Unit Reaction Definitions… on the main Reactor window. Note: Any data previously entered in the Reaction Data Category window will be transferred to the Unit Reaction Definitions window and used as default values. You can overwrite the data for a particular reactor in the Unit Reactions Definitions window for that reactor.


April 2014

Equilibrium Reactor You may supply the operation phase of the reactor in the Unit Reaction Definitions window. By clicking Equilibrium Data… in this window, you gain access to the fields where you may supply the following: Equilibrium Coefficients: Eight coefficients (A-H) of the equilibrium equation. Units: The temperature, weight, volume and pressure units of measure for the equilibrium equation can be changed by clicking on the underlined linked text. Options are restricted to ºR or ºK for the temperature units.

Conversion Reactor You may overwrite the stoichiometric coefficients for the first reaction in the selected reaction set by clicking the Define the Stoichiometry for the First Reaction check box. The values of stoichiometric coefficients are to be determined from the calculation results of the selected Calculator unit. Frequently, this feature is applied to use a single reaction to represent the overall reaction behavior in the reactor and, therefore, there is only a single reaction defined in the entire reaction set. The stoichiometric data displayed in the grid box are merely used to echo the reaction equation previously defined in the Reaction Data section.

Continuously Stirred Tank Reactor and Boiling Pot Reactor You may supply the reactor operation phase, reaction activity basis and kinetic rate calculation method in the CSTR Unit Reaction Definitions window. Reactor Operation Phase: The options are vapor or liquid phase for the CSTR, but restricted to liquid phase for the BPR. Reaction Activity Basis: For vapor phase, the options are Molar Concentration, Partial Pressure or Fugacity. For liquid phase, the options are Molar Concentration, Fugacity or Activity. Currently, only homogeneous reaction rate expressions based on either vapor or liquid phase reactions are allowed for the CSTR. For BPR's, heterogeneous reaction rate expressions are allowed. Kinetic Rate Calculation Method: The options are Power Law, User Added Subroutine or Kinetic Procedure. If the default is used, the reaction rates are computed by power law kinetics in the form of the general Arrhenius equation. For any of these methods, kinetic data can be entered through the Kinetic Data… button. Power Law: This is the default method.

Chapter 9


User-added Kinetic Subroutine: This option directs the CSTR module to use a User-added Subroutine (UAS) written in FORTRAN to perform reaction rate calculations. Specify a Subroutine Name in the Unit Kinetic Data window. The identifying arguments for the subroutine name “U1”, “U2” … “U5” correspond to user-added subroutines “USKIN1” … “USKIN5” respectively. After selecting the user-added kinetic subroutine, you can enter local values (i.e., specific just to this reactor) for variables to be used for the rate calculation. Use the upper left table to supply local values for an array of real variables, the lower left table for any array of integer variables and the upper right for an additional (Supplemental) array of real variables. These local data, kinetic reaction data specified in the selected reaction set, and thermo-physical property data of the reaction mixture will be provided to the selected kinetic subroutine for reaction rate calculations. Refer to the PRO/II User-added Subroutines User Manual for instructions on creating and installing UAS’s. Kinetic Procedure: This option directs the CSTR module to use a user-supplied in line kinetic Procedure to perform reaction rate calculations. After selecting the name of the Procedure (which must be first defined in the Procedure Data section), you can enter values for local variables similar to the procedure for the User Added Kinetic Subroutine mentioned above. Additionally, you may provide the values for those procedure variables (PDATA) used by the selected Procedure.

Plug Flow Reactor Data that may be specified for the Plug Flow Reactor are the same as those described above for the CSTR. Pre-exponential Factor: The pre-exponential factor for the kinetic power law rate

equation. The default is 1. Activation Energy: The activation energy for the kinetic power law rate equation. The default is 0. Temperature Exponent: The temperature exponent for the kinetic power law rate equation. The default is 0. Base Component: A base component must be supplied for the kinetic reaction rate report. Reaction Order and Activity Basis: As is done in the Reaction Data section on a global basis, the default reaction phase, reaction activity bases for both vapor and liquid phases, component reaction phase and kinetic orders that are used to define the kinetic rate expression can be entered here as local data for this reactor. Click Reaction Order and Activity Phase to specify the kinetic reaction order and activity phase for each component which appears in the rate expression. The vapor activity basis is used for


April 2014

all components specified with vapor activity phase while the liquid activity basis is used for all components specified with liquid activity phase.

Gibbs Reactor You may specify the phase of the reactor operation in the Unit Reaction Definitions window. The reaction phase options are Calculated (default), Vapor, Liquid, Vapor–Liquid, Liquid–Liquid or Vapor–Liquid–Liquid. If Calculated is selected, PRO/II determines the phase as part of the free energy minimization calculation. If a phase is selected, the calculations are based on the selected phase.

Extent of Reaction To specify the extent of a conversion reaction (in Equilibrium and Gibbs reactors only); click Extent of Reaction… on the main Reactor data entry window to open the Extent of Reaction window.

Conversion Reactor You may select the base component from which the conversion data were determined. If the base component is not selected (select “None”), the stoichiometric coefficients of the reaction are taken as the absolute moles reacted. You may supply constants for the second order temperature-dependent fractional conversion equation in this window. Default values for the constants are given in the table. Click on the underlined linked text to change the temperature units of measure for the conversion reaction. If the temperature units of measure are not specified locally, the problem temperature units are used.

Equilibrium Reactor The base component for user-supplied reactions must be specified in the Extent of Reaction window. You may access this window via the Reaction Set window, which contains a list of the reactions that have earlier been defined for the flowsheet. Upon choosing the desired equation, the Extent of Reaction window appears. (The base components of built-in reactions such as Shift and Methanation are predetermined and need not be supplied by the user.) You may specify the approach to conversion either as a temperature or a fractional approach. As was the case with the Conversion reactor, you may supply constants for the second order temperature-dependent fractional conversion equation in this window. Default values for the constants are given in the table. Click on the underlined linked text to change the temperature units of measure for the conversion reaction. If the temperature units of measure are not specified locally, the problem temperature units are used.

Chapter 9


Gibbs Reactor The extent of reaction can be provided on a global basis in the Extent of Reaction window (as a component percent converted, or as a component product rate). The extent of reaction can also be specified for each individual reaction as a temperature approach or a base component product rate.

Amount of Catalyst For boiling pot reactors only, you can specify the amount of a nonvolatile catalyst component on a weight or molar fraction, or total weight or mole basis in the Catalytic Components window (which may be reached by clicking Catalysts on the Reactor Data window). Before the button becomes active, the following conditions must be met: •

You must specify the catalytic component with a reaction stoichiometry of ‘0.’ (Input/Reaction Data(Enter Data…)/ Reaction Definitions(Definition)/ Reaction Components). See the previous section on Reaction Data for more information on defining reaction data sets.

•

You must specify the reaction order for the catalytic component as any number other than ‘0’ in the Reaction Order & Activity Phase window. This window may be accessed by clicking on the like-named button located on the Unit Reaction Definitions/Unit Kinetic Data window for the boiling pot reactor, or by the following path: Input/Reaction Data(Enter Data…)/Reaction Definitions/(K…)/Kinetic Reaction Data(Reaction Order & Activity Phase).

Pressure For conversion, equilibrium, Gibbs reactors and CSTR’s, click Pressure on the main Reactor window to enter the following reactor pressure options in the Pressure data entry window: Pressure Drop: Provide the pressure drop across the reactor. This defaults to 0 if not supplied. Outlet Pressure: The pressure at the reactor outlet. For the plug flow reactor, either the inlet and outlet pressure or a pressure profile along the reactor length (actual length, or percent or fraction of tube length) may be entered on the Pressure window: Inlet:

Either the pressure drop below feed (the default is 0 psi), or the inlet pressure may be supplied.

Outlet: Either the pressure drop below inlet (the default is 0 psi), or the outlet pressure may be supplied.


April 2014

Print Options For all reactor types except the Gibbs reactor, the following print option is available in the Print Options window: Print Calculation Path for Enthalpy Balance: This option prints the calculation path for the heat of reaction calculation.

Thermodynamic System The thermodynamic system of methods for the reactor calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the main Reactor window.

Reactor, Batch

General Information The Batch Reactor unit operation models material production as a result of simultaneous and/or sequential reactions in the liquid contents of a reactor vessel. Phase equilibrium analysis during the reaction allows for the tracking or removal of vapor phase products. The Batch Reactor may be run in a true batch simulation mode, with the reactants charged to the reactor vessel prior to the onset of reactions, and product taken from the vessel at the end of reaction process, or in a semi-batch mode where reactants may be introduced throughout the reaction process. Batch reactor calculations may also be integrated into a steady-state process simulation. The unit configuration automatically considers the presence of holding tanks for steady flow streams to provide the time-variant reactants to the batch unit. Implicit holding tanks are also considered for the product streams to provide a coupling of the time-variant process to the continuous process simulation environment. A representation of the product steady flow stream comes from an overall process time average of the quantity accumulated into a given product. Currently, the Batch Reactor supports only liquid-phase reactions. A reaction may produce one or more vapor constituents. Whether the vapor constituent(s) will return to the liquid phase and again be available for reaction(s) will be determined by equilibrium analysis done at the end of each time step.

Chapter 9


Thermodynamic System The thermodynamic system for the unit is selected by using the Thermodynamic System drop-down list box in the Batch Reactor dialog box. Batch Reactor also allows the use of electrolyte thermodynamic methods.

Detailed Information For detailed information about the use of the Batch Reactor unit operation, consult the PRO/II Add-On Modules User Guide.

Solid Separator

General Information The Solid Separator unit models the separation of solid phase material from a mixture of feed streams. The unit operates adiabatically at the lowest of the individual feed stream pressures.

Feed and Product Streams The solid separator unit can have up to ten (10) feed streams. The inlet thermal condition is determined by an adiabatic flash calculation at the lowest feed stream pressure. The solid separator requires both overhead and bottoms product streams.

Calculation Method The solid separator provides the option of specifying the fraction of the solid components in the total feed that is removed in the bottoms stream. The default fraction of the solid components removed in the bottoms stream is 1.00. An adiabatic flash calculation is used to determine the product phases and the outlet temperature based upon the thermal condition of the combined feed. The solid separator unit supports both VLE (two phase) and VLLE (three phase) calculations to determine the individual phase compositions. See the online Technical Information discussion entitled VLE Model and VLLE Model for more details. To access the main data entry window for VLE and VLLE calculations, select Tools/Binary VLE from the menu bar. This page intentionally is left blank.


April 2014

Splitter

General Information This unit may be used to split a single feed or mixture of feeds into two or more products of identical composition and phase condition. The outlet stream pressure may be specified, if desired, and an adiabatic flash used to determine the outlet temperature and phase. A choice of options is provided for splits in which insufficient feed is available to meet the specified product rates.

Feeds and Products A splitter may have multiple feed streams. The lowest feed pressure is used for the pressure of the combined feed. A splitter must have two or more product streams. All product streams have identical compositions and phase conditions. Phase separation of product streams is not available in this unit, and, if desired, a Flash unit operation must be used for this purpose.

Product Rate Specifications For a splitter with N product streams, N-1 product stream rates must be specified. Product rate specifications are supplied by clicking on the underlined hypertext strings in the Product Rate Specifications section of the Splitter main data entry window. All of the splitter product streams are listed and any one may be used for the unspecified rate. Specifications use the general specification format and are further described in the SPEC/VARY/DEFINE section of this chapter. Only specifications that are rate dependent are allowed, e.g., stream or component(s) rate total, stream or component(s) recovery, stream enthalpy, etc.

Outlet Pressure Specification The outlet pressure for the splitter products may be changed by applying a pressure drop to the lowest feed pressure. This value is supplied in the Pressure Specification window, which is accessed by clicking Pressure Specification… on the Splitter main data entry window. When a pressure drop is supplied, the resulting outlet temperature and phase condition are determined by an adiabatic flash calculation from the composite feed inlet conditions.

Chapter 9


Inadequate Feed Rate Options There are two options for situations in which insufficient feed is available to satisfy all product stream rate specifications. They may be selected by radio buttons on the Splitter main data entry window: Satisfy Each Specification in Order Until Feed is Exhausted: Each specification is satisfied in the order of the products until the feed is exhausted. The product stream that encounters insufficient feed is limited to the feed available and the remaining products are assigned zero rates. (This is the default option.) Satisfy Each Specification and Normalize Flow rates if Needed: All specified product rate specifications are satisfied and the resultant rates are normalized to the total feed rate. The product with the unspecified rate is assigned a zero flow. The order of the product streams in the list box may be changed, if desired, by clicking Change Stream Specification Order… on the Splitter main data entry window. You can reset a stream specification by clicking Reset Stream Specification on the Splitter main data entry window.

Thermodynamic System The thermodynamic system of methods to be used for splitter calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the Splitter main data entry window.

Stream Calculator

General Information The Stream Calculator unit blends any number of feed streams and splits them into two product streams with defined compositions and thermal condition. It may also be used to synthesize a product stream based on the blended feeds, or by defining the amount of each component in the stream.

Feeds and Products The stream calculator may have any number of feed streams. Scale factors (positive or negative) may be applied to all feeds in the Feed Scaling window in order to create a mixed feed with the desired composition. If scale factors other than 1.0 are used, the unit will not be in material balance. Multiple feed streams are flashed at the lowest feed stream pressure.


April 2014

For stream splitting, both the overhead and bottoms products are required. In order to create a stream, a pseudo-product must be defined. The feeds may be split and a product stream created in the same stream calculator unit. If there is no feed to the unit, only a pseudo-product may be synthesized. Pseudo-products are virtual rather than actual streams, and must not feed unit operations or otherwise participate in the material balance of the flowsheet. A multiphase product from the stream calculator may be separated into streams containing one or more phase. The allowable product stream phases are vapor, liquid, decanted water and mixed (vapor + liquid). A mixed phase product is not allowed with a vapor or a liquid product. The decanted water product is also used as the second liquid product phase with rigorous VLLE calculations. If any product, overheads or bottoms, has more than one stream attached, the phases must be allocated to the streams in the Product Phases window, which is accessed by clicking Product Phases in the overhead or bottoms product windows.

Mode of Operation The mode of operation is specified by the number of feeds and products attached to the unit so it is important to connect the streams correctly before entering the unit data.

Stream Splitting In order to define the component splits, specifications must be entered in the Product Specifications window to define how much of each component goes into either the overhead or the bottoms product. Specifications may be on single components or on ranges of contiguous components. Several specifications may be required and some may specify the amount of components in the overhead and others the amount in the bottoms product. Each component must appear in one, and only one, specification. The component rates, recovery or composition in a product may be specified. The thermal condition of the products may optionally be defined in the Overhead Product Conditions window and the Bottoms Product Conditions window. Pressure defaults to the lowest feed pressure. If no temperature specification is supplied for either product, the product temperatures are set equal at a value calculated from the enthalpy balance, using the duty entered on the Stream Calculator window. If one temperature is supplied, the other temperature is calculated to meet the enthalpy balance. If both temperatures are given, duty is calculated. Temperature specifications may be a temperature value, the temperature rise above the feed, dew or bubble point or an approach to dew or bubble point.

Chapter 9


Stream Synthesis In order to synthesize a pseudo-product, specifications must be entered in the Pseudo-product Specifications window to define how much of each component is in the product. Specifications may be on single components or on ranges of contiguous components and several specifications may be required. At least one specification must be defined. Any component that does not appear in a specification has a zero rate in the pseudo-product. If the unit has feeds, component rates, recovery, or composition in the product may be specified. Otherwise, the component rates must be defined. If there is no feed to the unit, pseudo-product thermal conditions must be defined in the Pseudo-product Conditions window. If there is a feed, the temperature and pressure specifications are optional. The pressure defaults to lowest feed pressure, and the temperature is calculated to satisfy the enthalpy balance. If a duty is supplied, it is used only for the stream splitting enthalpy balance. Duty is not used for the pseudo-product enthalpy balance. Temperature specifications may be a temperature value, a temperature rise above the feed, dew, or bubble point, or an approach to dew or bubble point. If there is no feed, a temperature rise specification is not allowed.

Negative Component Rates It is possible to specify the unit to generate negative component rates in a product stream. Options to handle this situation include: •

reset any negative rates to zero (this is the default)

•

reset the rates to their absolute value

•

the unit should fail.

Thermodynamic System The thermodynamic system of methods to be used for the stream Calculator may be selected by choosing a method from the Thermodynamic System drop-down list box on the Stream Calculator main data entry window.

SPEC/VARY/DEFINE General Information PRO/II has an extensive system of cross-referencing for flowsheet parameters. Flowsheet parameters include operating conditions for unit operations, calculated results from unit operations, and stream flows, compositions, and properties. For example, the supplied outlet pressure for a Pump, the calculated temperature for a dew point Flash, and the simulated D86 ninety-five percent distilled temperature for a Column product stream are all flowsheet parameters.


April 2014

Most unit operation parameters may be either DEFINE'd or SPEC'd relative to any other flowsheet parameter in the problem. Some unit operations may VARY a flowsheet parameter that would ordinarily remain constant at the input value. The table below summarizes the methods for cross-referencing flowsheet parameters: SPEC: A unit operation or stream performance specification (calculated result) must meet a desired value, either on an absolute basis or relative basis. VARY: A unit operation or stream flowsheet parameter is varied from the supplied value. DEFINE: A unit operation parameter is defined by cross-reference to another flowsheet parameter. PRO/II uses a common format for the Specification (SPEC), VARY, and DEFINE features. Each feature is discussed separately below. Tables are also presented with cross-reference availabilities of the flowsheet parameters for streams and the unit operations.

Specifications By definition, a SPEC always must be a calculated flowsheet result. The following unit operations use the generalized SPEC format to define the performance of the unit: Flash, Splitter, Column/Side Column, and Controller. A SPEC has the following general form: Parameter = value within the default tolerance A choice for the Parameter and a numeric entry for the value must be supplied by clicking the underlined hypertext strings to gain access to the pertinent data entry fields. Optionally, the tolerance basis may be changed from the default to absolute or relative and the default tolerance value of 0.02 replaced by direct entry. 

Click on the Parameter hypertext to access the Parameter window.



Choose the Stream or Unit from the drop-down list box.



Select the unit or stream name in the drop-down list box.



Finally, click on the Parameter hypertext and select the desired parameter from the window that is displayed. Note that only those unit or stream parameters that are valid for use as a SPEC are available.

If the SPEC is not related to another flowsheet parameter: 

Click OK to return to the unit specification.



Click on the value hypertext, and enter the desired numeric value for the SPEC.

Chapter 9


To create a mathematical expression for the SPEC: 

Select the = sign linked text and select an option from the pop-up window. Choices are as follows:

No Operator Primary parameter only (the default) + Operator Primary parameter plus reference parameter (SUM) - Operator Primary parameter minus reference parameter (DIFFERENCE) / Operator Primary parameter divided by reference parameter (RATIO) x Operator Primary parameter times reference parameter (TIMES) 

Select the Reference Parameter and click on the Parameter text string, and select the desired reference parameter from the list which is displayed.

Note: Only unit or stream parameters that are valid for use in SPEC’s are available. 

Click OK to return to the unit specification window; then click on the value linked text string to enter the desired numeric value for the SPEC.

The following examples illustrate the use of SPEC’s:

Example 1: Reid Vapor Pressure of stream S103 = 6.0 Unit or stream parameter = a value within a relative tolerance of 0.02 |

|

|

[6.0]

Specification Unit/Stream [Stream]


Stream Name {Parameter Window} [S103]

April 2014

Parameter [Vapor Pressure] Keyword analog: SPEC STREAM=S103, RVP, AS VALUE=6.0, RTOL=0.02

Example 2: Duty of exchanger X103 / Duty of exchanger X104 = 1.0 with relative tolerance of 0.001 Unit or stream parameter = a value within a relative tolerance of 0.001 |

|

|

|

[1.0] [absolute]

| [0.001]

Specification Unit/Stream [Heat Exchanger]

Unit Name {Parameter Window} [X103]

Parameter [Duty]

Reference: [/ Parameter =] Reference Parameter Unit/Stream [Heat Exchanger]

Unit Name {Parameter Window} [X104]

Parameter [Duty] Keyword analog: SPEC HX=X103, DUTY, DIVIDE, HX=X104, DUTY, VALUE=1.0, RTOL=0.001

Note: [ ] denotes user input.

VARY For each SPEC in a flowsheet, there must be one VARY to provide one degree of freedom. The VARY for the Flash unit is implicitly defined, i.e., not defined explicitly by the user. For Flash units with specifications, the degree of freedom is the temperature when the pressure or pressure drop is given and the pressure when the temperature is supplied. Other unit Operations which have VARY’s are

Chapter 9


the Column/Side Column and the Controller. A VARY is always a flowsheet parameter that has a fixed versus calculated value in the flowsheet. For Columns/Side Columns a VARY may be a feed stream rate, product draw rate, or a heat duty. For example, the lean oil feed rate to a column may be defined as a VARY in order to meet a specification on the propane recovery for the column. Ordinarily, the lean oil feed rate would have a fixed or constant rate in the flowsheet. Controllers have VARY’s that are associated with other unit operations. For example, the supplied outlet pressure for a Compressor may be a VARY for a Controller. Note that this flowsheet parameter would ordinarily have a fixed or constant value in the flowsheet. On the other hand, the calculated temperature for a dew point Flash unit could not be used as a VARY, since this is a flowsheet parameter that is determined by the flowsheet calculations. A VARY construct has the following general form: Vary Parameter To enter a parameter: 

Click on the underlined hypertext string to access the Variable window.



From this window, select the type of vary, i.e., stream or unit type, in the drop-down list box.



Next, select the unit or stream name in the adjacent drop-down list box.



Finally, click on the Parameter hypertext string and select the desired parameter to be varied from the list.

Note: Only unit or stream parameters that are valid for use as a VARY are available. The following example illustrates the use of VARY’s:

Example 3: The temperature for isothermal flash unit D101 is varied by a Controller. Vary unit or stream parameter | |

Specification Unit/Stream

Unit Name {Variable Window}

[Flash]

[D101]

Parameter [Temperature]


April 2014

Keyword analog: VARY FLASH=D101, TEMP Note: [ ] denotes user input.

DEFINE The DEFINE is used to dynamically define the value for a flowsheet parameter that ordinarily has a fixed versus calculated value in the flowsheet. Thus, the value for a unit operating condition may be set to a value that is based on a calculated flowsheet parameter. For example, the DEFINE may be used to set the temperature for an isothermal Flash to the temperature that is calculated for a Compressor outlet stream plus 10 degrees. This concept greatly enhances the flow-sheeting capability of PRO/II, and, in fact, nearly every unit operation input parameter may be DEFINE’d in PRO/II. To define a flowsheet parameter: 

Select the parameter in the appropriate window for the unit operation. At this point, the Define button on the toolbar is activated if the parameter may be DEFINE’d. Click Define to access the Definition window.



From this window, select the check box to enable the DEFINE options.



Click on the Parameter text string and select the desired parameter from the window which is displayed.

Note: Only unit or stream parameters that are valid for use as a DEFINE are available. 

If the DEFINE is not related to another flowsheet parameter click OK to return to the unit window. If the DEFINE is related to another flowsheet parameter, establish the appropriate mathematical relationship. Mathematical expressions for a DEFINE are created in a manner completely analogous to that described above on page 309 for a SPEC.



Select the reference parameter type in the same manner as used to select the primary parameter.



Click the OK button in the child windows to return to the unit operation window.

For a constant: 

Select Constant from the Constant/Stream/Unit drop-down list box in the Parameter window.



Enter a numerical constant in the supplied data entry field.

The following example illustrates the use of a DEFINE:

Chapter 9


Example 4: DEFINE the temperature for Flash drum D103 to be the temperature of stream S104 minus 15 degrees. [Select the temperature field on the Flash Second Specification] [Click Define from the Toolbar] [Select the check box to set up the Define] | Primary Parameter: Unit/Stream/Constant

Unit Name {Definition Window}

[Stream]

[S104]

Parameter [Temperature] Reference: [= Parameter - Parameter] Reference Parameter: Unit/Stream/Constant

Value

[Constant]

[15.0]

Note that the DEFINE is nearly identical in structure to the SPEC. Stream Parameters Available for Cross-referencing 1

SPECS

DEFINE

VARY

2

Flash

Splitter

Column

Controller

All Units

Controller

Temperature

Yes

-

Yes

Yes

Yes

Yes

Pressure

Yes

-

Yes

Yes

Yes

Yes

Enthalpy

Yes

-

Yes

Yes

Yes

-

Mole Weight

Yes

-

Yes

Yes

Yes

-

Total Flow

Yes

Yes

Yes

Yes

Yes

Yes

Component Flow

Yes

Yes

Yes

Yes

Yes

-

Composition

Yes

-

Yes

Yes

Yes

-

Phase Fraction

Yes

-

Yes

Yes

-

Parameter

Density/Volume

Yes

-

Yes

Yes

Yes

-

Distill. Curve

Yes

-

Yes

Yes

Yes

-

Vapor Pressure

Yes

-

Yes

Yes

Yes

-


April 2014

Transport Property

Yes

-

Yes

Yes

Yes

-

Refining Property

Yes

-

Yes

Yes

Yes

-

Special User Property

Yes

-

Yes

Yes

Yes

-

1. In general, any applicable stream property may be used to define a unit operating condition. Not all stream properties are applicable to all unit operating conditions. 2. With the exception of the Column, only the Controller may vary stream parameters. The Column may vary the total flow of a feed stream.

Unit Parameters Available for Cross-referencing Within Operation Parameter

SPEC

VARY

External DEFINE

Reference

Controllers 1

SPEC

VARY

Yes

Yes

Yes

Calculator Result

-

Yes

Yes

Parameter

-

Yes

Yes

Stream Calculator Temperature

-

Yes

Yes

-

Yes

Yes

Pressure

-

Yes

Yes

-

Yes

Yes

Delta T

-

Yes

Yes

-

Yes

Yes

Temp. Below Bubble Pt.

-

Yes

Yes

-

Yes

Yes

Temp. Above Dew Pt.

-

Yes

Yes

-

Yes

Yes

Delta P

-

Yes

Yes

-

Yes

Yes

Feed Cofactor

-

Yes

Yes

-

Yes

Yes

Duty

-

Yes

Yes

Yes

Yes

Yes

Frac. Overhead

-

Yes

Yes

-

Yes

Yes

Frac. Bottoms

-

Yes

Yes

-

Yes

Yes

Frac. Product

-

Yes

Yes

-

Yes

Yes

Overheat Rate

-

Yes

Yes

-

Yes

Yes

Bottoms Rate

-

Yes

Yes

-

Yes

Yes

Chapter 9



External

SPEC

VARY

DEFINE

Reference

Product Rate

-

Yes

Yes

Comp. Overhead

-

Yes

Comp. Bottoms

-

Comp. Product

-

Controllers 1

SPEC

VARY

-

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

Yes

Yes

Controller Specification

Yes

Yes

Yes MVC

Specification

Yes

Yes

Yes Optimizer

Specification

Yes

Yes

Yes

Yes

Yes

Constraint

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Column Reflux

Yes

Yes

Yes

Yes

Reflux Ratio

Yes

Yes

Yes

Yes

Yes

Yes

Duty

Yes

Yes

Yes

Yes

Yes

Yes

Feed Rate

-

Yes

Yes

Yes

Yes

Draw Rate

-

Yes

Yes

Yes

Yes

Specification

-

-

Yes

Yes

Yes

Percent of Flood

-

-

Yes

Yes

Yes

Yes

Max % of Flood

-

-

Yes

Yes

Yes

Yes

Downcomer B/U

-

-

Yes

Yes

Yes

Yes

Max D.C. B/U

-

-

Yes

Yes

Yes

Yes

CS Approach

-

-

Yes

Yes

Yes

Flood Approach

-

-

Yes

Yes

Yes

Tray Diameter

-

-

Yes

Yes

Yes

Yes

Max Tray Diam.

-

-

Yes

Yes

Yes

Yes

Condenser Pres

-

-

Yes

Yes

Yes

Top Tray Pres

-

-

Yes

Yes

Yes

Tray Delta P

-

-

Yes

Yes

Yes


April 2014


External

SPEC

VARY

DEFINE

Column Delta P

-

-

Yes

Tray Temp

-

-

Yes

Feed Tray No

-

-

Draw Tray No

-

-

Duty Tray No

-

Tray Effic Factor

Reference

Controllers 1

SPEC

VARY

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

-

Yes

Yes

Yes

Yes

P/A Rate

-

-

Yes

Yes

Yes

P/A Return T

-

-

Yes

Yes

Yes

Product Moles

-

-

Yes

Yes

Yes

Thermosiphon Reboiler Circulation Rate

-

-

Yes

Yes

Yes

Yes

Vapor Fraction

-

-

Yes

Yes

Yes

Yes

Liquid Fraction

-

-

Yes

Yes

Yes

Yes

Outlet Temp

-

-

Yes

Yes

Yes

Yes

Delta T incr.

-

-

Yes

Yes

Yes

Yes

LLEX Specification

-

-

Yes

Yes

Top Tray Pres

-

-

Yes

Yes

Feed Rate

-

Yes

Yes

Yes

Draw Rate

-

Yes

Yes

Yes

Duty

-

Yes

Yes

Yes

Pump Temperature

-

-

Yes

Outlet Pres

-

-

Yes

Yes

Yes

Yes

Delta P

-

-

Yes

Yes

Yes

Yes

Pressure ratio

-

-

Yes

Yes

Yes

Yes

Work

-

-

Yes

Yes

Head

-

-

Yes

Yes

Efficiency

-

-

Chapter 9

Yes

Yes

Yes



SPEC

VARY

External DEFINE

Reference

Controllers 1

SPEC

VARY

Pipe Diameter

-

-

Yes

Yes

Yes

Yes

Max velocity

-

-

Yes

Yes

Yes

Yes

Average velocity

-

-

Yes

Yes

Yes

Delta P

-

-

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Rel Roughness

-

-

Yes

Yes

Yes

Abs Roughness

-

-

Yes

Yes

Yes

Friction Factor

-

-

Yes

Yes

Yes

Flow Efficiency

-

-

Yes

Yes

Yes

Length

-

-

Yes

Yes

Yes

Heat Transfer Coeff.

-

-

Yes

Yes

Yes

Ambient Temp

-

-

Yes

Delta P Max

-

-

Yes

K-Factor

-

-

Yes

Yes

Yes

Simple Exchanger Duty

-

-

Yes

Yes

Yes

Yes

Cold Delta P

-

-

Yes

Yes

Yes

Yes

Cold T Out

-

-

Yes

Yes

Yes

Yes

Cold Liq Fr

-

-

Yes

Yes

Yes

Cold Subcool

-

-

Yes

Yes

Yes

Cold Sup’heat

-

-

Yes

Yes

Yes

Hot Delta P

-

-

Yes

Yes

Yes

Yes

Hot T Out

-

-

Yes

Yes

Hot Liq Fr ac

-

-

Yes

Yes

Hot Subcool

-

-

Yes

Yes

Hot Sup’heat

-

-

Yes

Yes

LMTD

-

-


Yes

Yes

Yes

April 2014


SPEC

VARY

Zoned LMTD

-

-

Overall U

-

-

Area

-

U * Area

-

Ft Factor

External DEFINE

Reference

Controllers 1

SPEC

VARY

Yes

Yes

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

-

Yes

Yes

Yes

Yes

Approach

-

-

Yes

Yes

Yes

Yes

MITA (Pinch)

-

-

Yes

Min. Approach

-

-

Yes

Yes Yes

Yes

Yes

Yes

Rigorous Heat Exchanger Duty

-

-

Yes

Yes

Yes

Overall U

-

-

Yes

Yes

Yes

Estimated U

-

-

Area

-

-

Yes

Yes

Yes

U*Area

-

-

Yes

LMTD

-

-

Shell T Out

-

-

Tube T Out

-

Tube Foul Factor

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

Yes

-

-

Yes

Yes

Yes

Yes

Shell Foul Factor

-

-

Yes

Yes

Yes

Yes

Required Foul Factor

-

-

Yes

Yes

Yes

Yes

Yes

LNG Heat Exchanger Duty

-

-

Cell i Temp Out

-

-

Yes

Yes

Yes

Yes

Cell i Duty

-

-

Yes

Yes

Yes

Yes

Cell I Delta P

-

-

Yes

Yes

U*Area

-

-

Yes

Yes

LMTD

-

-

Yes

Yes

MITA

-

-

Yes

Yes

Chapter 9

Yes



SPEC

VARY

External DEFINE

Reference

Controllers 1

SPEC

VARY

Splitter Temperature

-

-

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta P

-

-

Yes

Yes

Yes

Yes

Specification

-

-

Yes Valve

Temperature

-

-

Pressure

-

-

Delta P

-

-

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Compressor Outlet Temp

-

-

Yes

Yes

Yes

Yes

Outlet Pres

-

-

Yes

Yes

Yes

Yes

Delta P

-

-

Yes

Yes

Yes

Yes

Compr. Ratio

-

-

Yes

Yes

Yes

Yes

Actual Work

-

-

Yes

Yes

Yes

Yes

Head

-

-

Yes

Yes

Yes

Yes

Adiab. Efficiency

-

-

Yes

Yes

Yes

Yes

Poly Efficiency

-

-

Yes

Yes

Yes

Yes

Max. Press

-

-

Yes

Yes

Cooler DP

-

-

Yes

Yes

Cooler Temp

-

-

Yes

Yes

Temp Estimate

-

-

Yes

Yes

RPM

-

-

Yes

Yes

Yes

Curve RPM

-

-

Yes

Yes

Yes

Expander Outlet Temp

-

-

Yes

Yes

Yes

Outlet Pres

-

-

Yes

Yes

Yes

Yes

Pressure Drop

-

-

Yes

Yes

Yes

Yes

Expans. Ratio

-

-

Yes

Yes

Yes

Yes


April 2014


External

SPEC

VARY

DEFINE

Reference

Actual Work

-

-

Yes

Head

-

-

Adiab. Effy

-

Min. Pressure

-

Controllers 1

SPEC

VARY

Yes

Yes

Yes

Yes

Yes

Yes

-

Yes

Yes

Yes

-

Yes

Yes Yes

Flash Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Yes

Specification

-

-

Entrainment

-

-

Yes

Pseudo Prod.

-

-

Yes

Yes Yes

Mixer / Splitter Temperature

-

-

Pressure

-

-

Yes

Yes

Yes Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Specification

-

-

Yes Pump

Temperature

-

-

Yes

Yes

Yes

Outlet Pres

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Press Ratio

-

-

Yes

Yes

Yes

Yes

Work

-

-

Yes

Yes

Head

-

-

Yes

Yes

Efficiency

-

-

Chapter 9

Yes

Yes



SPEC

VARY

External DEFINE

Reference

Controllers 1

SPEC

VARY

Equilibrium Reactor Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Yes

Conversion i

-

-

Yes

Yes

Yes

Yes

Stoic. Coeff.

-

-

Yes

Conversion Reactor Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Yes

Conversion i

-

-

Yes

Yes

Yes

Yes

Gibbs Reactor Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Yes

PFR (Plug-Flow Reactor) Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta Pres

-

-

Yes

Yes

Inlet Pres.

-

-

Yes

Yes

Delta P In

-

-

Yes

Yes

Duty

-

-

Tube Diameter

-

-

Yes

Yes

Length

-

-

Yes

Yes

No. of Tubes

-

-

Yes

Yes

U (HTC)

-

-

Yes

Yes


Yes

Yes

Yes

Yes

April 2014


External

Controllers 1

SPEC

VARY

DEFINE

Reference

SPEC

VARY

Max Veloc.

-

-

Yes

Yes

Yes

Temp In

-

-

Yes

Yes

Yes

Temp Out

-

-

Yes

Yes

Pre-exp. Factor

-

-

Yes

Yes

Activation E i

-

-

Yes

Yes

Yes

Conversion i

-

-

Yes

Yes

Yes

CSTR/Boiling Pot Reactor Temperature

-

-

Yes

Yes

Yes

Yes

Pressure

-

-

Yes

Yes

Yes

Yes

Delta P

-

-

Yes

Yes

Yes

Yes

Duty

-

-

Yes

Yes

Yes

Yes

Conversion i

-

-

Yes

Yes

Pre-exp factor i

-

-

Yes

Yes

Yes

Activation E i

-

-

Yes

Yes

Yes

Volume

-

-

Yes

Yes

Yes

Min. Temp.

-

-

Yes

Yes

Max. Temp.

-

-

Yes

Yes

Max. Veloc.

-

-

Yes

Yes

Depressuring Final Pres.

-

-

Yes

Yes

Relief Pres.

-

-

Yes

Yes

Final Time

-

-

Yes

Yes

Relief Time

-

-

Yes

Yes

Relief Duration

-

-

Yes

Yes

Valve Constant

-

-

Yes

Yes

Valve Back P.

-

-

Yes

Yes

Valve Coeff.

-

-

Yes

Yes

Yes

Critical Flow Factor

-

-

Yes

Yes

Yes

Chapter 9

Yes

Yes Yes

Yes

Yes Yes

Yes

Yes Yes



External

Controllers 1

SPEC

VARY

DEFINE

Reference

SPEC

VARY

Init. Wet Area

-

-

Yes

Yes

Yes

HT Area

-

-

Yes

Yes

Yes

HT Coeff.

-

-

Yes

Yes

Yes

HTC Factor

-

-

Yes

Yes

Yes

Vapor HTC

-

-

Yes

Yes

Yes

Liquid HTC

-

-

Yes

Yes

Yes

Coeff. C1

-

-

Yes

Yes

Yes

Coeff. C2

-

-

Yes

Yes

Yes

Coeff. C3

-

-

Yes

Yes

Yes

Coeff. C4

-

-

Yes

Yes

Yes

Coeff. C5

-

-

Yes

Yes

Yes

Final Temp

-

-

Yes

Yes

Yes

Final Duty

-

-

Yes

Yes

Yes

Final Vent Rate

-

-

Yes

Yes

Yes

Vessel Volume

-

-

Yes

Yes

Liquid Holdup

-

-

Yes

Yes

Vessel Diameter

-

-

Yes

Yes

Vol. Corr. Factor

-

-

Yes

Yes

Ht. of Holdup

-

-

Yes

Yes

Vessel Weight

-

-

Yes

Yes

Vessel Cp

-

-

Yes

Yes

Tan-tan Vessel Length

-

-

Yes

Yes

Tan-tan Vessel Height

-

-

Yes

Yes

Time Step

-

-

Yes

Yes

Isentropic Eff.

-

-

Yes

Yes

Yes

Heat Scale Fac.

-

-

Yes

Yes

Yes

Area Scale Fac.

-

-

Yes

Yes

Yes

1 Available for any SPEC or DEFINE.


April 2014

User-added Unit Operations

General Information The PRO/II User-added Unit Operation capability enables users to add their own FORTRAN subroutines to simulate any type of unit operation or to perform calculations on flowsheet parameters. The subroutine must first be linked into the PRO/II program and it is then accessed via the graphical user interface in the same way as any other unit operation. The User-added Unit Operation has access to the PRO/II physical property data and may call the PRO/II flash and property calculation subroutines. Other information, such as input and output dimensional units, is also available. See the PRO/II Data Transfer System and User-Added Subroutine User Guide for information on writing and interfacing User-added Unit Operation subroutines. The developer of the User-added Unit Operation can also customize the Useradded Unit Operation Data window to request only data which may be required for the calculations. Note: If transport properties are required in the User-added Unit Operation, you must select a suitable method in the Thermodynamic Data.

Selecting the Subroutine When a User-added Unit Operation is laid down on the PFD, the User-added Unit Operation window opens in which the user must select the name of the required subroutine.

Calculation or Output Execution A User-added Unit Operation may be executed during the flowsheet convergence calculations or at output time only. The User-added Unit Operation Data window will show when the selected subroutine is calculated. This affects whether feeds and/or products are allowed. The default is to perform the calculations for the user-added unit as part of the normal flowsheet convergence calculations. Calculation time: The User-added Unit Operation is calculated as part of the normal flowsheet convergence. Additional calculations may be performed at output time and an output report may be produced.

Chapter 9


Output time: If the User-added Unit Operation requires only converged flowsheet data for calculations and reports, it can be executed at output time rather than during the flowsheet convergence.

Feeds and Products The User-added Unit Operation may have up to ten feed streams. The subroutine can retrieve each feed separately. They are not mixed or flashed. If they are to be mixed, the user must do this in the subroutine. User-added Unit Operations which are to be executed during the flowsheet convergence must have at least one feed stream. Those which are only executed at output time need not have any feeds. User-added Unit Operations which are to be executed during the flowsheet convergence may have up to ten product streams. These may be any combination of phases. User-added Unit Operations which are only executed at output time cannot have any product streams.

Stream Reordering If the User-added Unit Operation has more than one feed or product, they will be shown in the order in which they were laid down on the PFD. The user may need to reorder the streams so that they are presented in the correct order to the Useradded Unit Operation. For example, the User-added Unit Operation may always feed vapor to the first product stream and liquid to the second. Reordering is done in the User-added Subroutine - Stream Reordering window accessible by clicking Reorder Streams on the User-added Unit Operation Data window.

Entering Data Data are supplied to the User-added Unit Operation in four tables: •

Real Data (PARAM values, available to SPEC, VARY, DEFINE)

•

Supplemental Data

•

Integer Data

•

Heat Balance Data

Data can be supplied to a User-added Unit Operation using either a “Customized Data Entry Window” or the standard “Developers Data Entry Window.” These two choices are explained below. Data also may be entered into the variables in the Real Data table using the PRO/II Define feature. Only the variables in the Real Data table are available to


April 2014

other unit operations by using SPEC, VARY and DEFINE constructs. Data in the other tables are available only internally in each user-added subroutine.

“Customized” Data Entry Window Users have the option of defining a “Customized Data Entry Window” to use for all user-added unit operations that utilize a specific user-added calculation subroutine. The standard PRO/II User-added Unit Operations use the default names USER41 - USER60 (displayed as US1-US20). If you create a customized data entry window for a user-added calculation subroutine, the name that is selected for it replaces one of the default names in the list of available subroutine names (the list displayed when a user-added unit is laid down on the PFD).

Creating a “Customized” Q Data Entry Window To create a customized data entry window to be used for a specific user-added calculation subroutine, two ASCII files must be created in the directory specified by the “UserConfigDir= entry in the PVISION.INI file. These two files are called UASLIST.INI and USERXX.INI and are described below.

File UASLIST.INI This file contains the user-specified names for specific user-added calculation subroutines that will be displayed in place of the default names US1 - US20, corresponding to the subroutines USER41 - USER60. Each line in the file has two entries; the entry number in the list of user-added subroutine names, and the actual text that is to be displayed for the user-added subroutine. An example of a typical UASLIST.INI file is shown below: 1. PIPE DP Routine 2. Stream Heating Value These entries in the UASLIST.INI file will result in the following list of available user-added calculation subroutines being displayed when a User-added Unit Operation is laid down on the PFD:

File USERXX.INI This file contains the variable names and array locations for all of the Real, Supplemental, Integer, and Heat Balance Data values that the specific useradded calculation subroutine requires or that can be input by the user. For a user-added subroutine with a customized data entry window, a user will only be able to enter values for the data items specified in this file. The “XX” in the name of the USERXX.INI file corresponds to the respective user-added subroutine referenced, i.e. the user-added subroutine USER41 with a user-specified name of “PIPE DP Routine” above would need a “USER41.INI” file to describe the

Chapter 9


required data for the calculations. An example of a typical USERXX.INI file is shown below: Example: USER41.INI file: IPARM 1

iPPrint ControllN

Required

RPARM 1 iPDiameter (in)lm

Required

RPARM 2 iPLength (ft)lg

Required

... SUPPLE 1 “No. Of Segments”

Required

... The first entry on each line indicates to which data array the variable belongs. The second entry is the array number where the data value entered by the User will be stored for access by the User-added calculation subroutine. The third entry is the label to be displayed for the variable in the customized data entry window. This entry must be enclosed in double quotes (“”). The fourth entry on each line indicates whether or not data entry for the item is Optional or is Required. The default is Optional, and this entry is not required. The entries in the USER41.INI file shown above will result in the following required data values and variable names being shown in the custom window displayed for data entry, for any User-added Unit Operation where the userselected “PIPE DP Routine” as the user-added subroutine when the unit was laid down on the PFD as shown below.

Customized UAS Data Entry Window The order in which the variable labels appear on the customized User-added Unit Operation Data window is the same as the order in which they appear in the USERXX.INI file. The limits on the number of variables that can be entered for each array are shown below. These limits are: •

Real Data

- up to 500 elements

•

Supplemental Data

- up to 10,000 elements

•

Integer Data


•

Heat Balance Data

- up to 10 elements

Each table shows the name(s) of the variable(s) for which values must be entered. They will scroll if they contain more than four rows. All data entries


April 2014

displayed using a customized data entry window are required. No checks on validity or completeness of the data are carried out until the User-added Unit Operation is executed.

The Standard Developer’s Data Entry Window A special window is available for developers of User-added Unit Operations. It is the default window displayed for a User-added Unit Operation if a “Customized Data Entry Window” has not been defined for the specific unit. The developer’s data entry window has no variables names and any number of variables may be entered up to the limits of each array. These limits are: •

Real Data


•

Supplemental Data

- up to 10,000 elements

•

Integer Data


•

Heat Balance Data

- up to 10 elements

The user must know which elements of each array are used by the User-added Unit Operation and enter the array element number along with the value. Values may be entered for any or all of the elements in the arrays. The elements defined need not be contiguous and may be entered in any order. PRO/II knows nothing about the data requirements of a User-added Unit Operation and so no restrictions are imposed in the data entry. Note: Unless the user defines a custom Data Entry Window for a specified Useradded Unit Operation, the data entry for that unit will be via the developers' data entry window.

Modular User-Added Unit Operations The new modular interface for user-added subroutines first released in PRO/II 6.0 continues to evolve with this release. The interface addresses many of the limitations of the “classic” user-added interface described above. Enhancements have been made to all phases of simulation, including input, data cross-checking, data storage, calculations, and output reporting. These features are fully supported through both key words and the PROVISION Graphical User Interface. Highlights of the new functionality for user-added unit operations include: •

Almost no restrictions on the number of subroutines or their names (no reserved names).

•

User-defined data supports user-defined text labels that may be used in key word files to identify input data. Unlimited data size; defined and

Chapter 9


organized by the developer, including integer, double precision real, and text data. Scalar through two-dimensional arrays are allowed. •

Automated keyword input processing, using the user-defined data structures and data labels. Cross-check calls the user-added subroutine to perform its own data validation, in addition to generic cross-checks performed automatically by PRO/II.

•

Completely dynamic execution. No restrictions on the location of the dynamic-link libraries created by the developer. The DLL’s may be stored in a single location for access by multiple users.

•

Extensive new features for handling stream data, performing flash calculations. Improved access to the “native” PRO/II error processor.

•

Full support for user-defined output reports written to the standard PRO/II text report.

•

Full support for multi-sided models, such as heat exchangers.

•

User-defined units of measure, used for all data transfer between the user-added subroutines and PRO/II.

•

Full GUI support, including unit lay-down and custom input windows. User-developers may create these using the “AutoGui” feature with the user-defined data structures and labels.

Modular User-Added Utilities Modular utilities are called from PRO/II to perform specific calculations required by native PRO/II features. They always represent a user alternative to calculation ® methods already available in PRO/II. Currently, the RATEFRAC rate-based column algorithm is the only model that utilizes modular utilities. Available useradded utilities are supported for the following calculations in a column segment: •

Interfacial Area between fluid phases

•

Binary mass transfer coefficients in each fluid phase

•

Heat transfer coefficients

Detailed Information Comprehensive discussion of modular user-added subroutines is beyond the scope of this Guide. Please refer to the “PRO/II User-Added Subroutines User Guide”. ®



April 2014

Electrolyte Module General Information The optional Electrolyte Module of PRO/II allows you to handle systems containing electrolytes. See the PRO/II Add-On Modules User Guide for more information. The following unit operations can be used with this electrolyte version: •

Flash

•

Pump

•

Valve, Mixer, Splitter

•

Pipe

•

Simple heat exchanger, LNG heat exchanger

•

Conversion reactor, Equilibrium reactor

•

Stream calculator

•

Heating/Cooling curve

•

Calculator

•

Controller, Optimizer

•

Column (Electrolytic Algorithm, see below)

Thermodynamic Models Eight built-in electrolyte models in PRO/II simulate aqueous systems in a wide range of industrial applications. The models apply to fixed component lists with a predefined set of thermodynamic methods for K-values, enthalpies and densities. It is not possible to define individual methods for K-value, enthalpy or density when using electrolyte thermodynamic models. Note: Electrolyte models may not be used to calculate the following properties: (1) Non-aqueous electrolyte systems; (2) Free water decant; (3) Water dew points; (4) Hydrocarbon dew points, (5) Entropy and heat capacity. The following electrolyte models are available in this release: •

Amine Systems

•

Acid Systems

•

Mixed Salt Systems

Chapter 9


•

Sour Water Systems

•

Caustic Systems

•

Benfield Systems

•

Scrubber Systems

•

LLE and Hydrate Systems

To select an electrolyte model: •

Click Thermodynamic Data on the toolbar to open the Thermodynamics Data main data entry window.

•

Select the Electrolyte option in the Category list box.

•

Choose an appropriate electrolyte model.

The suggested range of applicability for the electrolyte models is summarized below: Temperature:

32-390 F (0-200 C)

Pressure:

0-200 atm

Dissolved gases:

0-30 mole %

Ionic solutes:

0-30 ionic strength

Amine Systems Pressure:

0-30 atm

LLE Systems Organic solutes:

0-10 weight %

You may add your own models, specifically suited to your application, by using the PRO/II and the Electrolyte Chemistry Wizard available from OLI Systems, PLC. If you wish to do this, contact your nearest SIMSCI support office for more information. Note: Take care when using non-electrolyte and electrolyte thermodynamic methods in the same application. The PRO/II electrolytic models use a different enthalpy basis from that used for other thermodynamic systems. When both are used, PRO/II automatically takes care of the difference but it may appear to be confusing. To avoid this, select the electrolyte enthalpy method for all non-electrolyte thermodynamic systems in a mixed application. All systems will then use the electrolyte model basis.


April 2014

Electrolytic Column Algorithm (ELDIST) This column algorithm was designed to solve non-ideal aqueous electrolytic distillation columns involving ionic species. It uses a Newton-Raphson method to solve the mass balance, vapor/liquid equilibrium and specification equations simultaneously. The K-values and enthalpies are supplied by the electrolyte thermodynamic model. The Electrolytic Column Algorithm is selected from the Column Algorithm dropdown list box on the Column main data entry window. Note: Electrolytic thermodynamic models only support VLE and so total phase draws are not permitted. Advantages and disadvantages of the Electrolytic Column Algorithm are given below: Advantages (1) Rigorously models ionic equilibrium systems. (2) Solves highly non-ideal distillation columns. Disadvantages (1) Side columns are not supported. (2) Pumparounds and tray hydraulics are not available. (3) Certain Column Specifications and Variables are not permitted.

Simsci Add-on Modules

Add-on modules can be obtained in this version of PRO/II to extend the functionality of the program. These modules include units for modeling polymer systems, separating solid components from feed streams, blending streams with different component and refinery inspection properties, as well as Profimatics hydrotreating and reformer reactor models.

SIMSCI POLYMER CSTR Unit Operation PRO/II contains features for handling polymers (e.g., van Krevelen property prediction method, polymer moment attributes, ALM thermodynamic method, and polymer flash).

Chapter 9


The SIMSCI Polymer CSTR Add-on Model offers you the capability of modeling a polymerization reactor operating under the following conditions: •

Single monomer producing a linear homo-polymer.

•

Single phase reaction (effects of heat and mass transfer on the mass transport are not considered).

•

Ideal CSTR (steady-state, well-mixed, constant volume reactor).

•

Free radical polymerization kinetics.

•

Bulk or solution polymerization.

This reactor unit has been added to PRO/II as part of the SIMSCI Add-on Models (Polymer CSTR) and is available from SIMSCI as the SIMSCI Polymer CSTR module. Required Data for the Polymer Reactor Unit This version of PRO/II does not allow you to enter the necessary Component, Stream, or Thermodynamic Data via required the data entry windows. However, you can enter the necessary Polymer CSTR data using the Polymer CSTR data entry window for the SIMSCI Add-on Model. To enter data for the Polymer CSTR: Once you have entered your simulation data, including the data for the Polymer CSTR, but excluding any polymer-specific thermodynamic, stream, or component data, you will need to do the following: •

Export the simulation data to a PRO/II keyword file.

•

Add the necessary polymer-specific data to the keyword file.

•

Import the modified keyword file into PRO/II and run the simulation problem in Run-Only mode.

For additional information, refer to the PRO/II Add-On Modules User Guide.

SIMSCI COMPONENT PROPERTY REPORTER Unit Operation This unit prints out the Component Properties and Refinery Inspection Properties for all the thermodynamic methods in the current flowsheet. This unit is selected from a drop-down list box on the SIMSCI Add-on Units main data entry window. No data input is required.


April 2014

SIMSCI BLEND Unit Operation The Blend unit allows you to blend two or more streams to give one product stream with different component and refinery inspection properties. This unit is selected from a drop-down list box on the SIMSCI Add-on Units main data entry window. The feed streams should have different thermodynamic methods for this unit to function correctly, but this is not necessary. The unit thermodynamic method must be different from any of the feed stream thermodynamic methods. The following data must be provided: •

Product stream temperature.

The product stream pressure may also be supplied, but if it is not given, the pressure will be set to the lowest feed stream pressure. The unit thermodynamic method component properties will be recalculated from the blend of the feed streams properties and will then be stored as part of that thermodynamic method data storage. Only petroleum and assay generated component properties will be recalculated; it is assumed that Library component properties do not change in the flowsheet. The unit first recalculates the normal boiling point, molecular weight and specific gravity for all the petroleum components. These recalculated properties are then used to re-characterize all the other petroleum fraction properties such as the critical temperature. Using the Blend Unit with Refinery Inspection Properties Any refinery inspection properties specified in the input will also be blended from the feed streams properties using the specified blending method for that property. It is necessary that every thermodynamic method must have the same refinery inspection properties specified and that these properties must use the same property method and blending basis in order for the unit to work. A check is done at input time to check that all the methods in the problem have the same refinery properties, methods and bases specified. You can request this check to be done, at calculation time, on the methods used in the current unit using the IPARM entry. Note: Requesting this check at calculation time should be used with care and is not recommended.

SIMSCI RESET Unit Operation The RESET unit allows you to reset the product stream enthalpy datum using the thermodynamic method specified within the unit. This unit is selected from a drop-down list box on the SIMSCI Add-on Units main data entry window. Only one feed and one product stream are allowed for the unit.

Chapter 9


Note: If you try to import a keyword file that specifies more than one feed or product stream, PRO/II will produce an input error. The feed stream pressure is always kept constant and you are required to specify whether the temperature, enthalpy, dew point, bubble point or vapor fraction is kept constant. The new product stream conditions will be calculated based on the option specified. The available calculation options are entered through the first value in the Integer Data for Unit field and are as follows: Value Entered Calculation Option 1

Specify the product stream at the feed stream temperature

2

Specify the product stream at the feed stream enthalpy

3

Specify the product stream at the feed stream vapor fraction

4

Specify the product stream at the dew temperature

5

Specify the product stream at the bubble temperature

Note: In this version, a warning message will alert you if the thermodynamic method of the unit operation is different from the thermodynamic method of any of the feed streams. This warning message applies to all unit operations except for the RESET unit, the BLEND unit and any Profimatics reactor models.

SIMSCI Profimatics Reactor Unit Operations These units model Profimatics Hydrotreater and Reformer Reactor unit operations and can be selected from a drop-down list box on the SIMSCI Add-on Units main data entry window.

Valve

General Information The Valve is used to model the Joule-Thompson effect that occurs across a pressure restriction such as a valve, orifice plate, etc. The temperature for the exit fluid is computed by assuming that the operation is adiabatic. Rigorous calculations may be performed for both VLE and VLLE systems.


April 2014

Feeds and Products A valve operation may have multiple feed streams, in which case the inlet pressure is assumed to be the lowest feed stream pressure. A valve may have one or more product streams. The product phase condition for valve operations with one product stream is automatically set by PRO/II. For valve units with two or more product streams, the product phases must be specified in the Valve Product Phases window which is accessed by clicking Product Phases… on the Valve main data entry window. Product phases allowable include: vapor, liquid, decanted water, heavy liquid, and mixed phase (vapor plus liquid). Mixed phase is mutually exclusive with vapor and liquid products and is not allowed when four product streams are specified.

Outlet Conditions The outlet condition for a valve is selected with the appropriate radio button on the Valve main data entry window as: •

Pressure drop

•

Outlet pressure

Thermodynamic System The thermodynamic system of methods to be used for valve calculations may be selected by choosing a method from the Thermodynamic System drop-down list box on the Valve main data entry window.

Wiped Film Evaporator

General Information The Wiped Film Evaporator unit operation (WFE) provides the capability to model the separation of solvents and/or monomers from a polymer melt. A Wiped Film Evaporator should be used when the removal of volatiles from a viscous polymer melt is diffusion limited. The blades inside the wiped film evaporator continually mix and spread a thin film of the melt on the wall of the evaporator. As the melt moves down the evaporator, the volatiles diffuse out of it and into the vapor space of the evaporator. The volatiles are pulled out of the evaporator under vacuum.

Chapter 9


Detailed Information For detailed information regarding operating modes, data requirements, and range of applicability of the Wiped Film Evaporator model, consult the PRO/II Add-On Modules User Guide.


April 2014

Chapter 10 Running and Viewing a Flowsheet This chapter describes how to run a simulation, interactively change the calculation sequence, use breakpoints, and view calculation history and results.

Using the Run Toolbar The PRO/II Run toolbar shown in Figure 10-1 provides options for data verification, interaction with the simulation (running the simulation by stepping through the units) and viewing convergence or simulation results. You access these features by choosing the appropriate button on the Run toolbar. If all required input data have not been provided when you choose Run, PRO/II will display a warning message telling you which data are incomplete. Display/hide the Run toolbar: 

Select/deselect the Run option from the shortcut menu. The Run toolbar appears/disappears on the PRO/II main window.

Figure 10-1: Run Palette

Chapter 10

Running and Viewing a Flowsheet 343

The toolbar displays push buttons that execute or access a feature: Operation

Description

Status

Displays the global messages for the current simulation.

Check Data

Checks the input data to determine whether there are any data inconsistencies.

Run

Executes the simulation, either from the beginning or from a breakpoint. Check Data is automatically performed, if necessary.

Step

Steps through the execution of the simulation by stopping at each unit operation in the calculation sequence.

Stop

Interrupts or stops the simulation while it is executing. The program completes its current calculation before stopping.

Set Breakpoints

Selects the units you want to assign as breakpoints. The program then executes the simulation, stopping at these breakpoints.

Goto

Starts the execution from any specified unit. You can select the unit by clicking the mouse cursor on the desired unit in the flowsheet.

Messages

Displays the calculation history as it is being produced. This window can be displayed when the PRO/II calculation engine is executing the simulation, in which case, the history will be updated as the calculation proceeds.

View Results

Displays the detailed output results of the highlighted unit operation or stream in the flowsheet of the previously run simulation. You can review the results of multiple units or streams, if desired. If the simulation has been run previously, you can view its results without executing it again by opening the appropriate .OUT file.

Show Breakpoints

Shows which units are assigned as breakpoints by displaying their icons in a different color. Clicking the button a second time disables the breakpoint display.

Checking the Simulation Status Use Status to display the Flowsheet Status window. This window allows you to view the global status messages for the current simulation. This button is highlighted as a selectable operation only if Check Data has been previously invoked either directly from the palette or indirectly from execution of the Run


April 2014

operation. The following colors around the Status button indicate the Check Data results: A red border indicates that errors were found. A yellow border indicates that warnings were generated. A black border indicates that no errors were found when Check Data was last performed. In all cases, the status can be viewed by selecting Status. To see the current global status messages for your simulation: 

Choose Status from the Run toolbar. The Flowsheet Status window appears. The Check Data results appear in a scrollable window.

Figure 10-2: Flowsheet Status If errors were detected, you must correct your simulation data. 

Choose Close to exit the Flowsheet Status window.



Correct your simulation errors.

If no errors were detected, run the simulation.

Understanding the Unit Color Coding Cues As the simulation progresses, you will observe that the individual units change color. Refer to the following for the default color codes.

Chapter 10


Unit Color Coding Color

Significance

Yellow

Unit operation at initial condition.

Red

Unit operation has not been solved.

Green

Unit operation in process of being calculated.

Blue

Unit operation has been solved.

Dark Blue

Unit operation has been calculated. This color is displayed only when you use the Run button, and a unit operation was previously calculated.

Purple

Breakpoint set directly before or after a unit operation.

Using the No Colors Feature If you do not wish to see the unit icon colors update as the flowsheet solves, you can get a performance benefit by deselecting the View/Show Run Colors option on the menu bar. This option operates exactly like the Run button on the Run palette, but unit icon colors are updated only when the simulation finishes or stops at a breakpoint.

Running the Simulation When you begin executing the simulation, the flowsheet convergence can be viewed in a Messages window by clicking Messages on the Run palette. You can close this window by clicking again on Messages or by double-clicking on the Message window’s control-menu box. Use Run to begin executing the simulation. The program starts from: 

The first unit, if this is the first run;



The unit at which the calculations were stopped;



The unit you selected using the Goto option.

The Run option automatically runs Check Data.

To begin executing the simulation: 

Choose Run from the Run toolbar.

When stepping through or stopping simulation execution, you may choose to examine the status of the simulation. 

Select Status from the Run toolbar.


April 2014



You may continue stepping through the simulation on a unit-by-unit basis by selecting Step.



Alternatively, you may choose to run the simulation without stepping by selecting Run.

If the run encounters problems, warnings will appear in the Flowsheet Status window. You have the option to close the window and correct the warnings or continue the run by clicking Run Simulation.

Stepping Through Simulation Execution Use Step to execute the calculations for the current unit (stopping at the next unit in the calculation sequence). In this manner, you can step through the execution of the simulation by stopping at each unit operation in the calculation sequence. To step through the execution of the simulation: 

Choose Step from the floating Run toolbar.

If the Messages window is open, you can observe that execution ceases after completion of the current unit.

Stopping Simulation Execution Use Stop to interrupt or stop the simulation while it is executing. The program completes its current calculation before stopping. To stop or interrupt simulation execution: 

Choose Stop from the Run toolbar.

The unit calculations stop. The next unit in the calculation sequence becomes the current unit, as indicated by its color.

Using Goto Use Goto to start execution from a selected unit. This can be invoked at program initiation or after execution pauses while stepping or stopping. To start the execution from a specified unit: 

Select a unit on the PFD.



Choose Goto from the Run toolbar.

The selected unit becomes the current unit. When execution completes on this unit, its Goto status is removed.

Chapter 10


Using Breakpoints You can set a breakpoint on any unit. Breakpoints can be before the unit operation, after it, or both. You can set breakpoints using the cursor or by utilizing the Breakpoints window. In addition, you can set breakpoints before and after a loop using the Breakpoints window. To set breakpoints using a cursor: 

Choose Set Breakpoints from the Run toolbar to turn on the Breakpoint mode. This automatically brings up the Breakpoints window.



Select the unit for which you want to set a breakpoint.



Choose Close to exit the Breakpoints window.

PRO/II turns units selected as breakpoints purple and updates the values in the Breakpoints window. To delete a breakpoint in Breakpoint mode: 

Select the unit. PRO/II will no longer show this unit as purple.

PRO/II updates the values in the Breakpoints window to show that there is no longer a breakpoint attached to this unit. The Breakpoints window lists all unit operations in the calculation sequence and identifies the breakpoint type for each unit: (before, after, both). Units without a breakpoint are considered “Off.” Breakpoints are for use during the current session. PRO/II does not save breakpoint information. To set breakpoints using the Breakpoints window: 

Choose Set Breakpoints from the Run toolbar. The Breakpoints window appears.

Note: Click Show Breakpoints to highlight those units or loops where breakpoints have been previously set.


April 2014

Figure 10-3: Breakpoints Window 

Set the desired breakpoint type by clicking on the check boxes. You can set before, after, or both.



Select a unit from the list.

The breakpoint for the unit is set based on the breakpoint placement you select. To close the Breakpoints window: 

Choose Close.

Note: Closing the Breakpoints window does not turn off Breakpoint mode. To turn off Breakpoint mode: 

Choose Set Breakpoints on the Run toolbar a second time.

Viewing Results Viewing Calculation History Use Messages to view the calculation history that has been produced so far. This can be used while the simulation is executing, after the simulation finally ends, or when the simulation reaches a breakpoint. To view the calculation history for the simulation thus far: 

Choose Messages from the Run toolbar.

Chapter 10


The Messages window appears. This is a multi-line data window that is continuously updated.

Viewing Results for Streams and Unit Operations Use View Results to display the results for the selected stream or unit in the default text editor. To view the results for a stream or unit: 

Select the desired stream or unit.



Click View Results



Choose View Results from the Run toolbar, or



Right-click on the unit and select “View Results” (for most unit operations other than columns), or



Right-click the unit and select “View results (Molar Units)” (for columns only), or



Right-click the unit and select “View results (Mass Units)” (for columns only).



Right-click the stream and select “View results (Molar Units)” or

on the toolbar, or

“View results (Mass Units)” Alternatively, you can view process unit and stream results via the Unit List and Stream List (Go To) windows: 

to open the Unit List or Stream List window

Click unit or stream .



Highlight the desired unit or stream.



Click View Results

.

The PRO/II report generator creates a single ASCII file. The default text editor displays the standard PRO/II output for the selected stream or unit.

Viewing Results in Stream Property Tables The stream property tables provide a convenient means to display selected results for a group of streams on the PFD. Four predefined report formats are supplied. These formats may be modified as desired and/or additional formats may be defined by the user. In addition to the stream properties selected for


April 2014

display, the titles and number of decimal places to display for each stream property may be chosen by the user. A quick check of the material balance for the problem may be accomplished by displaying the source and sink streams for the problem.

Selecting Streams for Property Tables Stream property tables are set up from the PFD palette by adding a stream properties icon to the PFD. 

Double-click the stream properties icon on the PFD to display the Stream Property Table window.



Choose the method for available stream selection by selecting the appropriate radio button:

Include All Streams: This is the default. All the streams in the flowsheet are displayed in the Available Streams list box. Include Flowsheet Source/Sink Streams: Only those streams entering the flowsheet as feeds and leaving the flowsheet as products are displayed in the Available Streams list box, producing a material balance check for the flowsheet. The streams in the Displayed Streams list box may be sorted using the Up, Down, Top and Bottom buttons.

Customizing the Stream Property Tables The appearance of a stream property table may be customized with options provided on the Stream Property Table window. The property list (format) to use for the display may be selected in the Property List to be Used list box. Note that in addition to the property lists supplied by PRO/II, the user may also prepare special property lists for selection. See Defining Stream Property Lists below for information. Contiguous strings of components may be grouped into a single component group for printout. For example, a C6 plus component group might be used to group all components from NC6 and heavier. Any number of component groups may be set up. To specify a component group, click Define Component Groups… on the Stream Property Table window to access the Group Components window. This window may be used to define and name component groups, as well as to edit existing component groups. The appearance of the steam property table itself may be altered by the user in the Stream Property Table window. Options include multiple rows per table,

Chapter 10


displaying the row grid lines, and setting the widths for the borders, lines, and property cell characters.

Defining Stream Property Lists (Formats) Stream property lists are defined and edited via the Define Property List window. This window is accessed by choosing Options/Stream Property Lists from the menu bar. PRO/II provides twelve default lists that may be edited if desired: Short Property List: Temperature, Pressure, Molar flow rate, Phase. Material Balance List: Temperature, Pressure, Molar flow rate, Phase, Molarbased composition. Stream Summary: Phase, Molar flow rate, Standard liquid flow rate, Temperature, Pressure, Molecular weight, Enthalpy, Specific enthalpy, Mole fraction liquid, Reduced temperature, Reduced pressure, Acentric factor, UOP K-value, Standard liquid density, Vapor and liquid molar flow rate, Vapor and liquid mass flow rate, Vapor and liquid volumetric flow rate, Vapor and liquid molecular weight, Vapor and liquid specific enthalpy, Vapor and liquid CP, Vapor and liquid density, Vapor and liquid viscosity, Vapor and liquid thermal conductivity, Liquid surface tension. Comp. Molar Rates: Molar component and total flow rates, Temperature, Pressure, Enthalpy, Molecular weight, Mole fraction vapor and liquid. Dry Stream Summary list: Similar to the Stream Summary list but ignoring water in the stream. Property Label list: Temperature, Pressure, Stream flow rate. Gas Report list: Temperature, Pressure, Weight rate, Molar rate, Enthalpy of the total stream. Molar rate, Weight rate, Actual volumetric rate, Standard vapor volumetric rate, C2+, C3+, Enthalpy, CP, CV, CP/CV ratio, Entropy, Ideal GHV, Ideal LHV, Wobbe index*, Molecular weight, Actual density, Compressibility, Pseudo-critical temperature, Pseudo-critical pressure, Viscosity, and Thermal conductivity of the dry vapor. Also, the Molar weight, Weight rate, Actual liquid volume rate, Standard liquid volume rate, Enthalpy, CP, Molecular weight, Actual density, Standard specific gravity, Viscosity, and Thermal conductivity of the dry liquid. Chemical Report list: Phase, Temperature, Pressure, Molar rate, Weight rate, Enthalpy, Molecular weight, Liquid mole fraction, Liquid weight fraction, Pseudo-critical temperature, Pseudo-critical pressure of the total stream. For the vapor, the Weight rate, the Actual volumetric rate, the Standard vapor volumetric rate, CP, CV, Molecular weight, Density, Compressibility, Vapor viscosity, and Thermal conductivity. For the liquid, Weight rate, Actual liquid volume rate, Standard liquid volume rate, CP, Molecular weight, Density, Viscosity, and Thermal conductivity.


April 2014

Dry Refinery Report list: Phase, Temperature, Pressure, Molar rate, Weight rate, Enthalpy, Molecular weight, Watson K, Flash point, RVP, TVP, Standard API gravity for the total dry stream. For the dry vapor, Weight rate, Actual vapor volume rate, Standard vapor volume rate, CP, CV, Molecular weight, Actual density, Compressibility, Standard specific gravity, Viscosity. For the dry liquid, Weight rate, Actual liquid volume rate, Standard liquid volume rate, CP, Molecular weight, Actual density, Standard API gravity, and Viscosity. Wet Refinery Report list: Similar to the Dry Refinery Report, but including the Water in the streams. Free Water Properties list: Mole fraction, Weight fraction, and LV fraction for Total water, Decant water, and Dissolved water in the stream. Comp Weight. Rates: Total mass and Weight Component rates, Temperature, Pressure, Enthalpy, Molecular weight, Weight fraction of vapor and liquid. To edit an existing property list:

 Use the drop-down list box to select the property list name. To create a new property list: 

Click New to access the New List window and enter a name for the new list in this window. This window also allows you to select an existing list from a drop-down list box to be copied to create the new list.

To add a property to a property list: 

Select the property in the Select Properties drop-down list box on the Define Property List window and click the button to transfer the property to the Property Description Format list box.

The property that was selected is expanded in this window, with the addition of a description and a format which may be edited in the data entry fields provided. The description for the property may be changed from the default value and the number of decimal places for printout may also be changed if desired. When editing an existing property list, properties may be selected in the Property Description Format list box and edited, deleted, or rearranged as desired. In addition to such properties as temperature, pressure, enthalpy, etc., property items such as “double line,” “line,” and “text” may be incorporated in a property list to add blank lines and special headings.

Chapter 10


How Stream Property Tables Persists on File Save and File Open Stream Property Tables are saved with the simulation (.prz) file. This allows the tables to be recreated at a later date or on a different installation and faithfully reproduce the original display. When that file is reopened and if the Stream Property List is not available in the current installation of PRO/II then the list will be created and permanently stored. If the list already exists on the installation and matches the attributes in the simulation file, PRO/II simply uses it. If the list already exists but does not match the simulation file then the user has to reconcile the lists with the choices as shown in Figure 10-9.

Figure 10-9: Stream Property – Pop-up Message while opening a .prz file

Mapping the Stream Property Table to the Stream Report Writer File Export During export, each Stream Property Table is mapped to an OUTPUT statement which will generate its own stream report. If one of the built-in Stream Property Lists is used (such as the Refinery Report), then the report will point to a standard built-in report format. If a custom stream property list is used then a custom FORMAT statement will be written in the keyword file. Output Report Generation The keyword file is re-printed in each output report with OUTPUT and FORMAT statements as described above. The output reports of simulations with Stream Property Tables will generate corresponding stream reports for each table. The


April 2014

formatting for each report will be the same as if they had use the Stream Report Writer function in keywords. File Import Importing keyword files that use the Stream Report Writer will map those reports into Stream Property Tables. If a FORMAT ID does not exist as a Stream Property List, a new Stream Property List will be created and permanently stored on the installation. If the OUTPUT ID already exists there will be a reconciliation step that allows the user to choose between the keyword OUTPUT ID (using the same or new ID), or the existing Stream Property List.

Figure 10-10: Stream Property – Pop-up Message importing a file with backup.sfd On File Export, PRO/II generates a backup graphical layout with a .sfd file extension where the size and position of Stream Property Tables are stored. This enables the correct position of the tables on re-import. A duplicate copy of the Stream Property List is also stored there. These will normally be in sync with the keyword file. If, for some reason they are not in sync, the backup .sfd file takes precedence. Note: In the absence of backup.sfd file, if the number of streams selected in Stream Report Writer definition is more than 12 then the corresponding Stream Property Table will be added to the block diagram during import. Refer to Keyword Manual, Chapter 9.5 – Stream Documentation for more information about Stream Report Writer using keywords.

Chapter 10


Running a Case Study Case Study is an executive level feature that allows you to perform studies on a base case solution by altering parameters selectively and rerunning the simulation. 

Access the Case Study main data entry window by selecting Input/Casestudy Data… from the menu bar.

Figure 10-11: Case Study Main Data Entry Window 

Enable the window by checking the Define Case Study box.

In this window, you can specify the changes you want to make to your input Parameters and to define the Results you want to examine. You may define as many parameters and results as you want. Parameters: The table of parameters initially has one row. You may insert or remove as many rows as you wish.


April 2014

Parameter Identifier: The parameter identifier defines the way you want the output data to be presented after the Case Study has been executed. A default identifier (here “PARAM1”) is supplied. To change the parameter identifier, click on the data field and enter a new name. Parameter: You must identify a parameter to change. Click Parameter to open the Parameter window. Select the parameter that you want to change. When you close this window, the parameter you have specified appears in place of the original text. Start Value: Click Base Case Value to open the Parameter Start Value window where you define the starting value for the parameter. The starting value defaults to the value of the parameter in the base case. When you close this window, the starting value will be displayed. Start Cycle: The start cycle is the cycle after which the incremental changes are implemented. Cycles before the start cycle use the value in the base case. If necessary, enter a new start cycle number. By default, the starting cycle is one (1). For “Case Study Matrix,” the Start Cycle field becomes invisible and by default, 1 is used as the Start Cycle value during the calculations. End Cycle: Cycles after the end cycle use the value in the end cycle. If necessary, enter a new end cycle number. The end cycle defaults to the value of the start cycle. In Case Study Matrix, the number of cycles specified for the parameter acts as its end cycle. The total number of cycles is equal to the product of all the cycles specified for the active parameters. For example, if you specify 5 cycles for the first parameter and 3 cycles for the second parameter and both the parameters are active then the total number of cycles is 15 (5 multiplied with 3). Step Value: Next, define the value of the incremental step change per cycle. The new step value will be displayed. Results: The table of results initially has one row. You may insert or remove as many rows as you wish. You may define a Result as one flowsheet parameter or as a function of two flowsheet parameters or as a function of one flowsheet parameter and a constant. See SPEC/ VARY/DEFINE in Chapter 9 for details on using and changing mathematical operators and composing specifications. Result Identifier: The result identifier will be used when you define how you want the output data to be presented after the Case Study has been executed. A default identifier is supplied. To change the result identifier, click on it and enter a new identifier.

Chapter 10


First Parameter: Click on the first (or only) parameter to open the Parameter window where you select the parameter that you want as a Result or as the first element of the function you are defining. Second (Reference) Parameter: Click on second parameter to open the Parameter window where you select the parameter (or constant) that you want as the second element of the function you are defining. Execution Options: Select from the Execute: list to execute the base case only or the base case and the case study. If you do not want to execute all the cycles of the case study, select Base Case and Specified Cycles and specify a beginning and ending cycle. First parameter cycles first: In Case Study Matrix, by default, the last parameter cycles first, which means the calculation starts at the last parameter. Selecting “First parameter cycles first” check box reverses the cycle and considers the first parameter first for the calculations.

Viewing Case Study Results Select Output/Case Study/Plots… or Output/Case Study/Table… from the menu bar to specify the format of the Case Study results. Enter a name (required) and an optional title for the plot or table. Click Data… to open a window where you specify the parameters and results to plot or tabulate. The dialog also has entries for labels of plot axes, table rows and columns, and other related data.

Running Files in Batch Mode You can execute one or more PRO/II ASCII keyword input files or flowsheet simulation files in Batch Mode from within PRO/II. The keyword input file may be one that was created using a text editor or word processor, or one that was previously created using the Keyword File Export capability. You can also execute flowsheet simulations that were created using PRO/II from the GUI, or were created by importing a PRO/II keyword input file. Batch execution generates the standard PRO/II ASCII output file for each simulation it runs. This occurs regardless of whether the selected files are keyword input files or simulation (.prz) files. While executing simulation problems in batch mode, you can continue to work with other Windows applications. You can terminate the currently executing problem or the batch execution mode completely by pushing the Terminate Current Problem or Terminate Batch Run buttons, respectively.


April 2014

To select a PRO/II keyword input file, simulation file (or group of files), or a previously stored execution list file: 

Close the currently open simulation.



Choose File/Run Batch from the menu bar. PRO/II displays the Run Batch - Input and/or Simulation Files Selection window.

Figure 10-12: Run Batch - Input and/or Simulation Files Selection Initially, there are no keyword input (*.INP) or simulation files (*.PR1) displayed in the File Sequence window. There are two methods of adding keyword input or simulation files to the file sequence list: 

Select the files explicitly using the Add Files… button, or



Load a previously saved list of files using the Load List… button.

Chapter 10


To select the desired keyword input or simulation files: 

Click Add Files…

PRO/II displays a list of available existing keyword input files. The default file type is keyword files (*.INP). You can change the file type to simulation files (*.PR1, *.PRZ) using the Files of type drop-down list-box.

Figure 10-13: Run Batch - File Select 

Type or select the name of the file that you want to execute. You can select multiple files within a given directory. Only the keyword input files highlighted in the currently selected directory will be added to the list of files to execute when you exit this window.



Click OK to validate your selection and return to the Run Batch - Input and/or Simulation Files Selection window.

To load an existing list of keyword input and/or simulation files: 

Click Load List….

PRO/II displays a list of available existing execution list files. The default file type is Run Batch List (*.LST). These files contain the complete path and name of keyword input and simulation files in the execution order previously specified by the user. An example of the typical contents of an execution list file is given below: C:\SIMSCI\PROII_W\USER\CASE1.INP C:\SIMSCI\PROII_W\USER\CASE2.INP


April 2014

C:\SIMSCI\PROII_W\USER\CASE3.INP Execution list files may include comment lines (beginning with a semicolon ;), and include list file directives given by #include followed by the .LST file name. An example is given below: ; This is a comment C:\SIMSCI\PROII_W\USER\CASE1.INP C:\SIMSCI\PROII_W\USER\CASE2.INP ; The following is the list of files to load. ; contains flash problems #include flash.LST Note: The #include directives may be nested, e.g., in the example above, flash.LST itself could contain the directives #include dewpt.LST and #include bubpt.LST.

Figure 10-14: Run Batch - Load File List 

Type or select the name of the execution list file that you want to load. You can select multiple list files within a given directory. Only the list files highlighted in the currently selected directory will be used to create the list of keyword input and simulation files to be executed.



Click OK to validate the selection and exit.

Chapter 10


When you return to the Run Batch - Input and/or Simulation Files Selection window, the contents of the previously selected execution list file(s) will have been expanded and are now displayed in the File Sequence list box. Selected files will be added to the bottom of the list of previously selected files displayed in the File Sequence list box.

Revising the File Execution Sequence Order After creating a list of files, you can revise the order of file execution. Simply highlight one or more files in the list and us the Move Up, Move Down, Move Top, and Move Bottom buttons. Clicking the Remove button only removes the highlighted file from the list; not from the hard drive.

Creating an Execution File List You can store a list of keyword input or simulation files as an Execution File List that can be retrieved and executed at a later date. 

Click Select from Lists….

PRO/II displays the Run Batch - Save File List As window containing the execution file list options.

Figure 10-15: Run Batch - Save File List As 

Enter a name for the Execution List File.



Click OK to store the list as a *.LST file in ASCII format.


April 2014

Executing the Batch List When you return to the Run Batch - Input and/or Simulation Files Selection window, you can begin the execution of the specified file list. To start the batch mode execution of the list: 

Click OK.

The specified list will be executed in the order shown in the File Sequence box. When the execution is complete, a message will be displayed to notify you that the batch mode execution has been completed.

Terminating Execution of a Batch List You have the choice of terminating the currently executing simulation problem, or terminating the batch mode execution completely. To terminate batch mode execution of the selected keyword files: 

Click Terminate Current Problem to terminate the currently executing problem.

Problem execution stops after the current unit calculations are complete. Note: You can terminate an executing problem only during calculation. To terminate batch mode execution completely: 

Click Terminate Batch Run to end the execution.

Viewing Output Results Results of Batch Execution of Keyword Input (*.INP) Files: By default, the program deletes the simulation files that remain after batch mode execution of specified keyword input files (*.INP). The standard PRO/II ASCII output report will be located in the corresponding .OUT file(s). Results of Batch Execution of Simulation (*.PR1, *.PRZ) Files: By default, the program will not delete the simulation files that remain after the batch mode execution of specified simulation files (*.PR1, *.PRZ), or the ASCII format standard output report located in the corresponding .OUT file. You can open the resulting simulation file(s) with the File/Open command, and then proceed to generate reports or modify the simulation flowsheet as desired in PRO/II. Whatever type of file (keyword input or simulation) was executed in batch mode, you can always view and edit the corresponding standard ASCII output files with any ASCII-capable text editor or word processor.

Chapter 10


Chapter 11 Printing and Plotting This chapter describes how to generate, view and print reports, and generate and print plots. Printer setup is also described.

Defining Output Reports PRO/II provides a variety of report options for streams, unit operations and dimensional units. You can change the output format of a report for any solved simulation without re-executing the simulation. To define the output format: 

Choose Output/Report Format from the menu bar. The Report Format menu appears with options for Units of Measure, Miscellaneous Data, Stream Properties, and Unit Operations.

Figure 11-1: Report Format Menu

Setting Miscellaneous Data Report Options You can set the report dimensions, identify the data you want to include and set the product stream scaling using the Miscellaneous Data option. To set miscellaneous data options: 

Choose the Option/Report Format/Miscellaneous Data from the menu bar. The Miscellaneous Report Options window appears.


April 2014

Figure 11-2: Miscellaneous Report Options

Chapter 11

Printing and Plotting 365

Setting Product Stream Scaling To change the scale stream flow rate: 

Choose Product Stream Scaling… from the Miscellaneous Report Options window. The Report Options - Product Stream Scaling window appears.



Select the Scale Stream Flow rate checkbox.



Specify the stream to be scaled, the components to be scaled, and the scaled flow rate.

Figure 11-3: Scale Stream Flow Rate 

Click OK twice to commit the changes and return to the PFD.


April 2014

Setting Stream Properties Report Options To set the stream properties report options: 

Choose the Output/Report Format/Stream Properties menu item. The Stream Property Report Options window appears (Figure 11-4).



Select the desired flow rate, fractions, or percent values for the Standard Component Flow rate/Composition Report.



Click OK to commit the entries and return to the PFD.

Figure 11-4: Stream Property Report Options

Setting Units of Measure Report Options In addition to the global, problem and unit level default units of measure you set for input data, you can also set Problem Units of Measure for output reports. You can change the output values for all the fields by applying a different units-ofmeasure set, or by making individual value adjustments. To set units of measure for output reports: 

Choose the Units of Measure menu item from the Report Format menu. The Default Units of Measure for Problem Output Report window appears.

Chapter 11


Figure 11-5: Default Units of Measure for Problem Output Report 

Click Initialize from UOM Library… to extract default values from another set or replace the default values, as necessary.


April 2014



Optionally, click Standard Vapor Conditions… to change the vapor condition settings for this problem. The Problem Standard Vapor Condition window appears.

Figure 11-6: Problem Standard Vapor Conditions 

Specify the desired standard vapor conditions. The calculated Standard Vapor Volume value is displayed by using the standard temperature and pressure when the check box is ON.



Click OK in the child windows to return to the PFD.

Setting Unit Operations Report Options You can set specific print options for each type of unit operation.

Chapter 11


To set the unit operations report options: 

Choose the Output/Report Format/Unit Operations menu item. The Unit Operation Output Report Options window appears.

Figure 11-7: Unit Operations Output Report Options 

Select the desired unit operation.


April 2014



Choose Print Options… The Column Print Options window appears.

Figure 11-8: Column Print Options 

Select the items you want to include in a Column Report.

Chapter 11




Optionally, click Plot Column Results… to set options for a plot. The Column Plot Options window appears.

Figure 11-9: Column Plot Options 

Click OK in the child windows, then Close to commit the entries and return to the PFD.

Generating a Report You can generate a report to a file. Use the Define Format option to define the format of the report. To generate a report from an executed simulation: 

on the toolbar, or choose Output/Generate Click Generate Reports Reports from the menu bar.

As PRO/II generates the report, a window appears, displaying the status of the report as it runs. Once the report has been generated, the default editor window appears displaying the contents of the report. PRO/II appends an .OUT


April 2014

extension to the current simulation name and saves the file in the USER directory.

Viewing a Report To view a previously generated report of the current simulation: 

Choose Output/View Report from the menu bar.

To view a previously generated report for any simulation: 

Choose File/Open from the menu bar.



Select Report Files in the List Files of Type list box and choose the desired file.

Printing a Report To print the report: 

Print from your text editor while viewing the report, or



Choose File/Print from the menu bar.



Select Report in the Print drop-down list box in the Print window.



Click OK.

Plotting PRO/II generates and displays a variety of plots for input data and tabulated results. The following plots can be generated: •

Input Data

•

Assay stream analysis

•

Output Results

•

Distillation column profiles (temperature, flow rates, composition, and separation factor)

•

Zones analysis for simple and rigorous heat exchangers

•

Phase envelopes

•

Heating/Cooling curves

Plots can be displayed using PRO/II’s Plot Viewer or Microsoft Excel. The section Setting Up the Plot Driver later in this chapter describes how to select and configure the plot driver.

Chapter 11


Generating a Plot To generate an assay stream analysis plot, select View Curve... on the Stream Assay Definition window. Three curves will be generated: •

The actual user input distillation data

•

The regressed TBP curve

•

The component cuts generated.

To generate one of the output results that PRO/II supports: 

Choose Output/Generate Plot from the menu bar. PRO/II displays the Generate Plot window as shown in Figure 11-10.

Figure 11-10: Generate Plot Window By default, the Units for Selection list box displays all the Unit Operations in the flowsheet that can provide data for plots. If you check the Selected Units option, only those units you previously selected on the PFD for which plots are available will be shown. When you select a unit operation in the Units for Selection list box, the Available Plots list box displays all plots available for that unit. You may select a plot then click Plot… to display the plot. If the plot requires additional options to be chosen, the Plot… button will change to an Options… button. Currently, additional data is required only for Distillation Column Plots.


April 2014

Plotting a Column To obtain a plot of vapor and liquid compositions: 

Choose Vapor and Liquid Compositions; then choose Options… to open the Column Vapor and Liquid Composition Plot window.

Figure 11-11: Column Vapor and Liquid Composition Plot 

Enter the additional data required.



Click Plot….

Setting Up the Plot Driver PRO/II can display plots using its internal Plot Viewer or Microsoft Excel (through version 7). The PRO/II Plot Viewer is a built-in utility that also prints plots. Microsoft Excel provides a complete set of formatting features. With Excel, you can change plot colors, axis titles, and other attributes to create a presentationquality graph. To select and configure the plot driver: 

Choose Options/Plot Setup on the menu bar to open the Plot Setup dialog. PRO/II’s installation wizard initially set up the options in this window.

Chapter 11




Select the desired plot driver using the drop-down list box.

Figure 11-12: Plot Setup Window To configure the currently selected plot driver: 

Press Setup to display the Setup Plot Driver window.

You cannot configure the PRO/II Plot Viewer (option “SIMSCI”).

Figure 11-13: Setup Plot Driver Window


April 2014

The configuration options are: Driver File: The complete path and filename of the dynamic link library (DLL) for the plot driver. Driver Function: The function name to invoke the driver. Command Line: The full command line to invoke the plotting application. Options: Additional driver-specific options.

The Plot Viewer PRO/II’s Plot Viewer utility lets you view a plot, print it, copy it to the clipboard, and export its data to a file. Modifications of plot attributes are not supported. If you want access to comprehensive editing and formatting features for your plot, choose the Excel plot driver. To save a plot: 

Choose File/Save As from the Plot window menu.



Enter the desired plot file name and click OK.

You can send a plot from the Plot window to your plotter. To send a plot to the plotter: 

Choose File/Print from the Plot window menu.

To export a plot to an ASCII file: 

Choose File/Export from the Plot window menu.



Select the file type (tab- or comma-delimited) and click OK.

To copy the plot image to the clipboard: 

Choose Edit/Copy from the Plot window menu.

Setting Up the Printer To set up the printer: 

Choose File/Print Setup from the menu bar.



Select a printer.



Select paper orientation and size and click OK.

Chapter 11


Printing a Flowsheet Layout To print a flowsheet diagram: 

Choose File/Print from the menu bar.



Select the range of pages and click OK.


April 2014

Chapter 12 Customizing the PFD Workplace This chapter surveys the customization of PFD appearance. You can control unit and stream appearance, modify the stream property tables, and set the font style used on your PFD.

Changing Unit Operation Styles PRO/II allows users to specify a different icon, name, label, and label starting number for each type of unit operation. Figure 12-1 illustrates the global Unit Style dialog.

Chapter 12

Customizing the PDF Workplace 379

Figure 12-1: Global Unit Style Window

Changing the Unit Icon Globally To Change the Style of A Unit Globally: 

Choose Options/Drawing Defaults/Unit Display… from the menu bar. The Unit Style window shown in Figure 12-1 appears.



Select the type of unit operation you want to change using the drop-down list box at the top of the dialog.



Enter label changes in the Auto Label Format field. In Figure 12-1, the field contains the string “F%d”.

The changes do not apply to any unit operations already present on the flowsheet drawing. They apply only to new unit operations added after the changes are made. Syntax of Auto Label Format: The Auto Label Format defines the template used to generate labels for one type of unit operation (see Auto Label Starting Number below). Each type of unit operation uses a separate Auto Label Format. The syntax of the template is: “prefix %d suffix”, where prefix and suffix represent any text, and %d is a macro command that displays the unit number. The label may not contain spaces or underscores. For example, an Auto Label Format field containing FDrum-%d-A. would generate a series of labels in the form FDrum-1-A, FDrum-2-A, FDrum-3-A, as three new unit operations of this type are added to the flowsheet. Auto Label Starting Number: This field defines the starting unit number used to generate the series of labels defined by the Auto Label Format field. The number must be an integer equal to or greater than zero. For example, setting this field to 7 starts unit numbering at 7. Assuming the Auto Label Format for the Flash unit operation were FDrum-%d, subsequent Flash units placed on the PFD would be labeled FDrum-7, FDrum-8, and so forth. Using Alternative Icons The Unit Style dialog includes a list of icons available to represent the unit operation. Simply highlight the desired icon in the scroll box. The selected icon will be used for all unit operations of this type subsequently added to the flowsheet drawing.


April 2014

Changing the Font of the Label Click the Select button in the Unit Labels group box of the Unit Style dialog to open the Font dialog. The topic Changing the Default Font (later in this chapter) describes modifying the type face and type size used in the label.

Changing the Unit Icon for a Single Unit It is possible to specify a different display icon for any unit operation currently shown in the simulation flowsheet. Some unit operations may be represented by any of several different icons. This choice is particularly useful when modeling different variants of the same unit operation. Note: Any available icon may be assigned to a User-Added Subroutine. To change the style of a single unit: 

In the PFD window, right-click the icon of the unit to modify. The unit menu shown in Figure 12-2 appears.



Select Display.. from this menu (or select Edit/Display Style… from the menu bar) to open the Unit Style window for the selected unit type.

As shown in Figure 12-3, the Unit Style for a specific unit operation does not require selecting the unit type, and does not allow changing the Auto Label fields. (Compare to Figure 12-1.) This prevents conflicts with the global labeling discussed previously.

Figure 12-2: Unit Menu

Using Alternative Icons The Unit Style dialog shown in Figure 12-3 includes a list of icons available to represent the unit operation. Simply highlight the desired icon in the scroll

Chapter 12


box. The selected icon is used only for the specific unit operation (already highlighted on the flowsheet drawing).

Figure 12-3: Individual Unit Style Window Changing the Label Font Click the Select button in the Unit Labels group box of the Unit Style dialog to open the Font dialog. The topic Changing the Default Font later in this chapter describes modifying the attributes of the font used in the label.

Changing the Label Displayed for a Specific Unit PRO/II automatically labels each unit placed on the PFD using the global Auto Label fields (see Figure 12-1). You can change the label for an individual unit, but cannot alter the auto-numbering sequence. To change a unit label: 

Double-click on the unit on the PFD, (or right-click the unit icon and select Data Entry.. from the unit menu).



Type over the existing text in the “Unit” label field of the data entry window. Note: the field does not allow a percent sign (%), which prevents redefining the autonumbering macro.


April 2014



Commit the change by pressing OK.

Changing Stream Styles The display of streams on the PFD may be customized globally (for all streams) or individually. By definition, global settings serve as defaults, while settings for individual streams are over-rides of the global settings. To help maintain a consistent appearance, customization of individual streams is limited and cannot override all global settings. A related set of customizations allows modifying the ToolTip display. For example, instead of changing a stream label to always display a property list, the ToolTip could display the property list only when the mouse cursor hovers over a stream. Because the stream display remains unchanged, this approach leaves the PFD uncluttered, while still providing convenient access to the information in the property table.

Changing the Global Stream Style The options for changing stream labels function in the same manner as changing unit labels (described earlier in this chapter), and the format syntax is the same. The global Stream Style dialog allows customizing the following attributes: •

The height and width of the arrows

•

The fill of the arrows

•

The segments on which the arrows appear

•

The label format

•

The starting number for auto-generated stream labels

•

The stream label location

•

The stream label border (shape) and font attributes

•

The stream label type (stream ID or list of properties)

•

ToolTip display (stream ID or list of properties)

•

The contents of the property list (material balance, gas report, etc.)

To Change the Default Style of Streams: 

Choose Options/Drawing Defaults/Stream Display… from the menu bar to open the global Stream Style dialog shown in Figure 12-4.

Chapter 12




Configure the desired options for Stream Arrows, Stream Labels, and Font. The Stream Tooltip Display options do not affect the default stream style directly (these features are described later in this chapter).



Click OK to apply the changes.

If all the changes do not propagate automatically to the PDF drawing, click the View/Redraw option on the menu bar.

Figure 12-4: Global Stream Style Dialog


April 2014

Sample Custom Stream Display As illustrated in Figure 12-5, default stream labels display simple stream ID’s, have rectangular borders, and appear on the stream line. Process stream arrows are not filled, and appear only on the horizontal segments of orthogonal process streams.

Figure 12-5: Default Stream Style

Chapter 12


Figure 12-6 illustrates the same flowsheet after using the following options from the global Stream Styles dialog: • Stream Label Location: Above Line with Stem • Stream Label Border: Diamond • Stream Arrows: Height: 10; Width: 20 • Fill Arrows

Figure 12-6: Sample of Typical Custom Stream Style These are merely samples of the available customizations. The global settings always apply to new streams added to the flowsheet, but existing streams are not automatically updated. This avoids changing streams that already have local style settings. The topic Changing An Individual Stream Style (later in this chapter) describes how to apply new global settings to individual streams.

Display Stream Property Lists As Stream Labels PRO/II allows you to display various stream properties on labels attached to the streams on the PFD. Display options include: •

Select a global property list for all stream labels in the flowsheet

•

Choose from a group of predefined property lists

•

Create a custom stream label property list

•

Position property labels anywhere (on or beside) streams on the PFD

•

Choose the type of border for any label

•

Choose a different font for any label


April 2014

To Select a Global Default Steam Property: 

Choose Options/Drawing Defaults/Stream Display… from the menu bar to open the Stream Style window.



From the Stream Label Type drop-down list, choose the Properties option.



Choose one of the predefined property lists and click OK to commit your choice.

The selected property list will appear on all streams subsequently added to the PFD.

Create Custom Stream Property Lists PRO/II allows you to create custom property lists for use in Stream Property Tables. You can use the same property list in more than one simulation. The default Stream Property Table is outlined by a single-lined rectangular box. You may arrange the properties in any desired order, and you may separate entries by single or double horizontal lines to improve the legibility of the list. To select a property list: 

Choose Options/Stream Property Lists from the menu bar to display the Define Property List window (Figure 12-7).

Figure 12-7: Define Stream Property List Dialog 

Select a list from the Property List box (Figure 12-8).

Chapter 12


Figure 12-8: A Typical Property List 

You can add or delete properties, modify the property description and change the numerical format.

To create a property list: 

Choose New… from the Define Property List window. The New List window appears.

Figure 12-9: New List Window 

Enter a name for the new list, or



Select the list from which you want to copy an existing property list.



Choose OK to commit the entries.


April 2014

To add one or more properties to a list: 

Select the desired properties. (The usual Windows click, shift-click and control-click selection options are supported.)



Choose Add->.

The selected properties are added to the bottom of the property list. To change the order of the properties in a list: 

Select the properties you want to move.



Use the Up, Down, Top, Bottom buttons to move the selected properties.

To change the description or the format of a property: 

Select the property you want to change.



Enter the new description and format in the entry fields under the property list.



Commit the changes using the Replace button.

To delete a property from a list: 

Select the properties you want to delete.



Choose Remove.

To clear (delete) all properties from a list:  Choose Clear. To demarcate sections of a list:  Insert single or double horizontal lines where desired.

Changing the Style of an Individual Stream Each stream provides the ability to over-ride some of the global stream style settings. These over-rides apply only to the specific stream of interest. Limitations exist to prevent compromising certain global features, such as the stream numbering sequence.

Chapter 12


To Modify the Style of an Individual Stream: 

Right-click a stream on the PDF to open its Stream Menu, as shown in Figure 12-10.



Click the Display item to open the individual Stream Style dialog. (shown below in Figure 1211).

Figure 12-10: Stream Menu

Figure 12-11: Individual Stream Style Dialog 

Choose any of the options in the individual Stream Style menu. Notice they are limited to some label properties and font formatting. They behave analogously to the same options described above for the global Stream Style dialog.



To remove all local over-rides and re-apply the global Stream Style settings, click the Restore Defaults button.



Click the OK button to apply the changes to this one stream.

Changing the ID Name of an Individual Stream PRO/II automatically labels each new stream as it is placed on the PFD. You can change the number or label for just one stream without altering the ongoing numbering sequence.


April 2014

To change a stream label: 

Double-click on the stream to open the Stream Data window. Alternatively, right-click on the stream and choose Data Entry….

Figure 12-12: Stream Data Entry Window 

Enter the new stream name in the Stream entry field.

Positioning Stream Property Labels on the PFD You may place stream labels on, above, below or beside the streams on the PFD. The labels may appear with or without stems connecting them to the streams. To position stream labels: 

Choose Options/Drawing Defaults/Stream Display… from the menu bar.



Select the desired position from the Stream Label Location drop-down list.



Click OK to commit your selection.

Alternatively, drag a stream label to any of these positions from the PFD itself. While in the Stream Styles window, you may also choose a text font and

Chapter 12


a border style for the labels from the corresponding drop-down lists.

Toggle Stream Property List Button Users may configure a stream property table to display on demand by using the Stream Toggle button on the PRO/II tool bar. Clicking the Stream Toggle button switches all stream labels to display the property table. Clicking again switches back to the stream label display. Before the button is used, a property list should be selected and assigned to the button. 

Choose Options/Drawing Defaults/Stream Display… from the menu bar to open the global Stream Style dialog shown in Figure 12-13.



Select a property table to be controlled by the toggle button. Figure 12-13 highlights the Toggle Stream Property List box in red.

Figure 12-13: Toggle Stream Property List 

Click the OK button to complete the configuration.

Users may choose any one of the stream property tables in the drop-down list. The "Property Label List" is the default selection. All custom property tables created by users are included in the drop-down list. They are available for selection, just as any of the pre-defined property tables.


April 2014

Adding the Toggle Stream Button to the Tool Bar If the Stream Toggle button is not already on the tool bar, it must be added to make the feature available for use. 

Choose View/Toolbar… from the menu bar to open the Toolbar Customization dialog shown in Figure 12-14.

Figure 12-14: Adding the Toggle Stream Button to the Tool Bar 

Scroll the Available Items: list box and highlight the Toggle Stream entry as shown in the figure.



Click the Add -> button to move the Toggle Stream entry to the Selected Items list. (The Add -> button is circled in blue in Figure 12-14.)



Use the Up, Down, Top, and Bottom buttons at the right side of the dialog to position the Toggle Stream button in the desired location in the list of selected items. The list order determines the position of items on the tool bar.



Click the OK button to complete the installation.

Click the button on the toolbar and observe that all stream labels change to the selected property table. This is illustrated in Figure 12-15.

Chapter 12


Figure 12-15: The Toggle Stream Button Displays A Property List Instead of the Stream Labels 

Click the Toggle Stream button again to change back to the normal stream ID display.


April 2014

Customizing Stream ToolTips PRO/II supports customizable tool tips for streams. As shown in Figure 12-16, hovering the mouse cursor over a stream displays the stream label. While the default stream tooltip displays the stream label, PRO/II allows reconfiguring stream tooltips to display a stream property list instead of the stream label. This is similar to replacing stream labels with stream property list in the global and individual stream display styles (described earlier in this chapter). It also is similar to configuring the Toggle Streams button.

Figure 12-16: Default Stream Label ToolTip

Chapter 12


To Configure the Stream ToolTip: 

Choose Options/Drawing Defaults/Stream Display… from the menu bar to open the global Stream Style dialog.



Scroll the Stream Tooltip Display list box and highlight an option.

The Stream Tooltip Display list box shown in Figure 12-17 is highlighted in green in the Stream Style dialog is shown in Figure 12-13. Click the OK button to complete the installation.

Figure 12-17: Stream ToolTip Display List Box

Most entries in the Stream Tooltip Display list box are the names of stream property lists. The Off entry sets the tooltip to display the basic stream label. It is the default setting. .Figure 12-18 illustrates displays by both the Toggle Stream and the customized ToolTips features.

Figure 12-18: ToolTip and Stream Label Displaying Stream Property Lists


April 2014

Modifying Drawing Preferences Drawing preferences include settings for snap and move tolerances, zoom and pan increments, the PFD palette icon, icon fill, unit snapping, and delete confirmation. To modify drawing preferences: 

Choose Options/Drawing Defaults/General… from the menu bar.

The General Drawing Defaults window appears with current settings. The settings can be changed as desired.

Specifying a Default Editor You can specify a default editor (such as Brief, Edit or Notepad) for use with PRO/II to display output reports and keyword input files. Using the editor, you can save any displayed text to a file or printer. The default editor is the Programmer’s File Editor (pfe.exe). To specify a default editor: 

Choose Options/Editor from the menu bar to open the Set Text Editor window.



Enter the full path name to the editor executable program file.

Figure 12-19: Set Text Editor

Changing the Default Font The Default Font option enables you to set the default font, font style, and size used in PRO/II’s main and data entry windows. This option is useful when the

Chapter 12


default font size for your system is too large for PRO/II’s data entry windows. Note that you cannot change the fonts for the title, menu, and status bar text. Also, changing the font size does not change the size of PRO/II’s windows. To specify the default font:  Choose Options/Font from the menu bar to display the Font dialog. 

Choose the desired font, font style, and size.

Figure 12-13: Font Window


April 2014

Index Define, 33

Aligning Text, 82 Basics Simulation, 32 Boiling Pot Reactor, 304

Continuous Stirred Tank Reactor, 300 Control Menu, 16 Convergence Test for, 50

Border Handles, 15 Bounding Box Changing the size, 87 Moving, 87

Conversion and Equilibrium Reactors, 300 Copy stream property table, 53

Button

to Excel, 54

PFD Palette, 21 Buttons

Data Default, 39

Delete, 29 Help, 29 Run/Results, 28

Data Entry Window Buttons, 26 Default global override, 56

Toolbar, 21

units of measure, 57

Toolbar, customizing, 29 Using Data Entry, 26 Using Navigation, 27 View, 29 VLE tools, 28 Calculator calculator, 151 cancel

Depressuring Unit, 218 Dissolver, 223 edit text, 82 Entering Text, 73 Excel Unit, 231 Expander, 237 Exporting Drawing to clipboard, 51

Unit placement, 67

keyword file, 49

Cancel

stream property table, 51

Delete, 67

to AutoCAD, 52

Changing Window Size, 15 Column, Side, 195

Features Unsupported, 47

Components, 34 file

Index I

import keyword input, 46 Fill from Structures, 90

Menus Using, 17

Fixed Properties, 108

Minimize/Maximize Buttons, 15

Flash, 239

Mixer, 273

Flash With Solids, 242

mode

Floating Palettes. See Flowsheet Building, 34, 55 Connect Unit Operations, 32 Define Components, 33 Draw, 32 Flowsheet Optimizer, 243 Gibbs Reactor, 305 Go To Buttons, 27 Heat Exchanger Air Cooled, 250 LNG, 248 Rigorous, 251 Simple, 260 Heat Exchanger, Lng, 248 Heat Exchanger, Rigorous, 251 Heat Exchanger, Simple, 260 Heating/Cooling Curves, 264 Help Button, 29 Henry’s Law, 119 import Keyword input file, 46 Importing a PRO/II keyword input file, 46 Linked text, 102 Main Window Using, 30

Run Only, 47, 48 Multiple View and PFD Palette Buttons, 21 Multivariable Controller, 274 Objects Deselecting, 79 Flipping, 81 Moving, 80 Rearranging, 80 Resizing, 79 Rotating, 81 Selecting all, 78 Selecting group, 78 Palettes Using, 20 Pan Left, Right, Up or Down, 87 Panning, 86 PFD Toolbar button, 21 Phase Envelope, 276 Pipe, 280 Properties Transport, 123 Property Methods Thermodynamic and Transport, 33 Pump, 294

II PRO/II User Guide

April 2014

Reactor Polymer Reactor, 285

Copying to Excel, 54 Declaring components, 34

Reactor, Batch, 311

Default data, 39

Report options, 368

Define Components. See Components, Define

Run/Results Buttons, 28 Save Current Simulation, 41 Save as dialog box, 42 Simulation to another name, 41 Screen Color Coding, 16 Scroll Bar Horizontal, 15 Vertical, 15 Scrolling increments, 83 PFD, 83 Select all objects, 78 Group of objects, 78 Multiple objects, 77 Set Breakpoints, 351 Setting Up the Printer, 381 Simsci Add-On Modules, 341 Simulation Analyze results, 34 Basics, 32 Building the flowsheet, 34 Closing, 43 Connect Streams, 32 Copying, 44

Deleting, 43 Draw Flowsheet, 32 Exporting to AutoCAD, 54 Opening, 40 Opening an existing simulation, 41 Run Only mode, 48 Save current, 41 Saving, 41 Savings to another file name, 42 setting preferences, 55 setting units of measure, 57 Simulation Data Exporting to a keyword file, 50 Simulation defaults Problem Description, 56 Units of measure, 56 Simulation Defaults, 56 Snapping, 66 Solid Separator, 312 Splitter, 313 Spreadsheet Tools Using, 53 Starting PRO/II, 12 Stream Calculator, 314 Stream Information, 35 Stream Property, 51

Index III

Temperature-Dependent Properties, 109 Thermodynamic Methods, 35 Toolbar Buttons, 21 Customizing, 29 Navigation buttons, 27 Tools Spreadsheet, 53

Unit Operations, 35 Connect, 32 Units of Measure Library, 59 User defined special properties Thermodynamic Data, 144 User-Added Unit Operations, 167, 333 User-defined Special Properties, 140, 142 Valve, 344

Transport properties, 123

Vertical Scroll Bar, 15

turn off, 353

View Buttons, 29

Unit data entry window, 36

Viewing Results, 354

unit icon, 66

VLE Tools Buttons, 28

unit opeartion

Water Decant Options, 124

Cyclone, 207 unit operation, 150 Column, Batch, 171

Window Changing Position, 16 Customizing, 15

compressor, 197

Wiped Film Evaporator, 345

Controller, 201

Zoom Area, 29

Crystallizer, 204

Zoom Increment, 84

Distillation, 172

Zooming, 83

IV PRO/II User Guide

April 2014

Invensys Systems, Inc. 26561 Rancho Parkway South Lake Forest, CA 92630 United States of America http://iom.invensys.com Global Customer Support Inside U.S.: 1-866-746-6477 Outside U.S.: 1-508-549-2424 or contact your local Invensys Representative. Email: [email protected] Website: http://support.ips.invensys.com

User Guide of PRO II 9.3

Recommend Documents