Aspen Polymer

Aspen Polymers Plus

www.iran-eng.com Examples & Applications Applications

Version Number: 2006 October 2006 Copyright (c) 2006 by Aspen Technology, Inc. All rights reserved. Aspen Polymers Plus, aspenONE, the aspen leaf logo and Plantelligence and Enterprise Optimization are trademarks or registered trademarks of Aspen Technology, Inc., Cambridge, MA. All other brand and product names are trademarks or registered trademarks of their respective companies. This document is intended as a guide to using AspenTech's software. This documentation contains AspenTech proprietary and confidential information and may not be disclosed, used, or copied without the prior consent of AspenTech or as set forth in the applicable license agreement. Users are solely responsible for the proper use of the software and the application of the results obtained. Although AspenTech has tested the software and reviewed the documentation, the sole warranty for the software may be found in the applicable license agreement between AspenTech and the user. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS DOCUMENTATION, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. Aspen Technology, Inc. Ten Canal Park Cambridge, MA 02141-2201 USA Phone: (1) (617) 949-1000 Toll Free: (1) (888) 996-7001 Fax: (1) (617) 949-1030 URL: http://www.aspentech.com

Contents Introducin Introducing g Aspen Polymers Polymers Plus .............. .......................... ......................... .......................... .......................... ....................... .......... 1 About This Manual.......................................................................................... Manual.. ........................................................................................ 1 Related Documentation................................................................................... Documentation................................................................................... 3 Technical Technical Support Support .. .......................................................................................... ........................................................................................ 3 A1 Creating a Simulation Simulation Model.. Model............. ....................... ........................ ........................ ......................... ......................... ................ .... 5 Creating a New Run........................................................................................ Run.. ...................................................................................... 5 Creating the Process Flowsheet Flowsheet ........................................................................ .. ...................................................................... 6 Placing Placing Blocks Blocks and Streams Streams .. ................................................................... ................................................................. 6 Renaming Blocks and Streams Streams ............................................................... .. ............................................................. 7 Specifying Setup and Global Options................................................................. Options................................................................. 7 Entering a Simulation Title..................................................................... Title.. ................................................................... 8 Defining Defining Unit-Sets Unit-Sets .. ................................................................................ .............................................................................. 8 Entering a Simulation Description Description ........................................................... ........................................................... 8 Defining Defining Report Report Options .. ........................................................................ ...................................................................... 9 Specifying Specifying Other Simulation Simulation Options .. ....................................................... ..................................................... 9 Specifying Components................................................................................... Components................................................................................... 9 Characterizing Polymers................................................................................. Polymers... ..............................................................................10 10 Specifying Physical Properties ......................................................................... ... ......................................................................11 11 Specifying Feed Streams ................................................................................ ................................................................................12 12 Specifying Specifying Kinetics Kinetics ... ........................................................................................ .....................................................................................13 13 Modifying Reactions............................................................................. Reactions.............................................................................13 13 Specifying Gel Effect............................................................................ Effect............................................................................15 15 Defining the Unit Operation Block .................................................................... ....................................................................16 16 Entering Block Specifications................................................................. Specifications... ..............................................................16 16 Improving Improving Convergence Convergence ... ....................................................................... ....................................................................17 17 Overriding Overriding Global Global Values ... ...................................................................... ...................................................................17 17 Entering Entering Mixer Specifica Specifications tions ... ................................................................ .............................................................17 17 Running the Simulation.................................................................................. Simulation..................................................................................18 18 Examining Examining Simulation Simulation Results ... ......................................................................... ......................................................................18 18 Input Input Summar Summary y .................................................................................. ..................................................................................19 19 Plotting Plotting Distribution Distributions s ... ..................................................................................... ..................................................................................22 22 Creating Live Distribution Plots........................................................................ Plots........................................................................23 23 Viewing Plots for Multiple Simulations..................................................... Simulations.....................................................24 24 Pasting and Linking Between Aspen Aspen Polymers Plus and Excel ............................... ... ............................26 26 Saving the Run and Exiting............................................................................. Exiting... ..........................................................................27 27 A2 Predicting Physical Properties................ Properties............................. .......................... .......................... .......................... .................. ..... 28 Defining the Simulation.................................................................................. Simulation..................................................................................29 29 Creating a New Run............................................................................. Run... ..........................................................................29 29 Specifying Setup and Global Options ...................................................... ......................................................30 30 Specifying and Characterizing Components ............................................. ... ..........................................30 30

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Specifying Physical Properties ............................................................... ... ............................................................31 31 Defining Molecular Molecular Structure Structure ................................................................. .................................................................32 32 Specifying Mass Mass Fraction Crystallinity ..................................................... .....................................................33 33 Creating Property Sets ......................................................................... .........................................................................33 33 Creating Property Tables ...................................................................... ... ...................................................................34 34 Running the Simulation Simulation and Examining Examining the Results ............................................ ............................................35 35 Input Input Summar Summary y .................................................................................. ..................................................................................37 37 References... References................................................................................................... ................................................................................................38 38 A3 Regressing Property Parameters................ Parameters............................ ......................... ......................... ........................ ................ .... 39 Defining the Simulation.................................................................................. Simulation..................................................................................40 40 Creating a New Run............................................................................. Run... ..........................................................................40 40 Specifying Setup and Global Options ...................................................... ......................................................40 40 Specifying and Characterizing Components ............................................. ... ..........................................41 41 Specifying Specifying Physical Physical Property Property Method ... ...................................................... ...................................................42 42 Entering Entering Experimental Experimental Data ... .................................................................. ...............................................................42 42 Specifying a Regression Regression Case ................................................................ ................................................................45 45 Specifying Physical Property Parameters................................................. Parameters... ..............................................46 46 Running the Simulation Simulation and Examining Examining the Results ............................................ ............................................47 47 Input Input Summar Summary y .................................................................................. ..................................................................................48 48 References... References................................................................................................... ................................................................................................50 50 A4 Fitting Kinetic Parameters............... Parameters........................... ......................... .......................... .......................... ......................... .............. 51 Defining the Simulation.................................................................................. Simulation..................................................................................52 52 Creating a New Run............................................................................. Run... ..........................................................................52 52 Creating the the Process Process Flowsheet ............................................................. ... ..........................................................52 52 Specifying Setup and Global Options ...................................................... ......................................................54 54 Specifying and Characterizing Components ............................................. ... ..........................................55 55 Specifying Physical Properties ............................................................... ... ............................................................56 56 Specifying Polymerization Kinetics ......................................................... .........................................................57 57 Supplying Process Information .............................................................. ... ...........................................................59 59 Specifying Data Regression................................................................... Regression... ................................................................61 61 Running the Simulation Simulation and Examining Examining the Results ............................................ ............................................65 65 Input Input Summar Summary y .................................................................................. ..................................................................................66 66 A5 Fractionating Oligomers... Oligomers ............... ......................... .......................... .......................... .......................... ......................... ............... ... 69 Defining the Simulation.................................................................................. Simulation..................................................................................69 69 Creating a New Run............................................................................. Run... ..........................................................................70 70 Creating the the Process Process Flowsheet ............................................................. ... ..........................................................70 70 Specifying Setup and Global Options ...................................................... ......................................................71 71 Specifying and Characterizing Components ............................................. ... ..........................................72 72 Specifying Physical Properties ............................................................... ... ............................................................73 73 Supplying Process Information .............................................................. ... ...........................................................76 76 Running the Simulation Simulation and Examining Examining the Results ............................................ ............................................77 77 Input Input Summar Summary y .................................................................................. ..................................................................................79 79 References... References................................................................................................... ................................................................................................81 81 A6 Calculating End-Use Properties .............. .......................... ......................... ......................... ......................... .................... ....... 82 Defining the Simulation.................................................................................. Simulation..................................................................................82 82 Creating a New Run............................................................................. Run... ..........................................................................83 83 Creating the the Process Process Flowsheet ............................................................. ... ..........................................................83 83

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Specifying Setup and Global Options ...................................................... ......................................................84 84 Specifying and Characterizing Components ............................................. ... ..........................................84 84 Specifying Physical Properties ............................................................... ... ............................................................85 85 Supplying Process Information .............................................................. ... ...........................................................86 86 Creating Creating a Sensitivity Sensitivity Table Table ... .................................................................. ...............................................................87 87 Running the Simulation Simulation and Examining Examining the Results ............................................ ............................................89 89 Input Input Summar Summary y .................................................................................. ..................................................................................89 89 References... References................................................................................................... ................................................................................................91 91 Section B - User Models............... Models... ......................... .......................... ......................... ......................... ......................... ....................... ........... 92 Installing Polymer User Model Library............................................................... Library... ............................................................92 92 B1 Polymer Fractionation Algorithm............... Algorithm............................ .......................... ......................... ......................... ................ ... 94 Installing the Polymer Fractionation Fractionation Examples... Examples ................................................... ................................................95 95 Creating a Working Directory Directory ................................................................ ................................................................95 95 Developing a Proprietary Model ....................................................................... .......................................................................95 95 Opening Opening the the Model Model ... .............................................................................. ...........................................................................95 95 Specifying Pseudo-Componenets ........................................................... ...........................................................95 95 Running the Example........................................................................... Example... ........................................................................96 96 Example Polymer Fractionation Model - PolFrac1... ............................................. .............................................96 96 Input Input Summar Summary y .................................................................................. ..................................................................................97 97 Stream Stream Report .... .................................................................................. .............................................................................. 100 Example Polymer Fractionation Model - PolFrac2.... .......................................... 103 Input Summary Summary .... ................................................................................ ............................................................................ 106 Stream Stream Report .... .................................................................................. .............................................................................. 108 References.... References................................................................................................. ............................................................................................. 109 B2 Aspen Polymers Plus-Predici Interface .... .................. ........................... ........................... .......................... ............ 110 Developing a Proprietary Model .... ..................................................................... ................................................................. 110 Opening Opening the the Model Model .... ............................................................................ ........................................................................ 110 Mapping Mapping the Components Components .... ................................................................... ............................................................... 111 Specifying Stream Flash Flash .... ..................................................................... ................................................................. 113 Running the Example......................................................................... Example.... ..................................................................... 114 Example Predici Four CSTR Model.................................................................. Model.... .............................................................. 114 Result Results s .... ............................................................................................ 115 Input Summary Summary .... ................................................................................ ............................................................................ 116 Stream Stream Report .... .................................................................................. .............................................................................. 118 C1 Polystyrene Bulk Bulk Polymerization by Thermal Initiation .... ................................. .............................121 121 About This Process Process .... ...................................................................................... .................................................................................. 121 Process Definition........................................................................................ Definition........................................................................................ 121 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 122 Physical Property Models and Data....................................................... Data.... ................................................... 123 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 123 Process Studies................................................................................. Studies.... ............................................................................. 124 Selected Simulation Results.......................................................................... Results.......................................................................... 128 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 130 References.... References................................................................................................. ............................................................................................. 132

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C2 Polystyrene with Styrene Monomer Monomer Distillation Distillation.... ................. .......................... .......................... ............... .. 133 About This Process Process .... ...................................................................................... .................................................................................. 133 Process Definition........................................................................................ Definition........................................................................................ 133 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 134 Polymers and and Segments .... ..................................................................... ................................................................. 135 Physical Property Models and Data....................................................... Data.... ................................................... 135 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 136 Inhibi Inhibitor tor .... .......................................................................................... 136 Process Studies................................................................................. Studies.... ............................................................................. 136 Selected Simulation Results.......................................................................... Results.......................................................................... 141 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 143 References.... References................................................................................................. ............................................................................................. 146 C3 Expanded Polystyrene Suspension Polymerization.... Polymerization................ ......................... ........................ ........... 147 About This Process Process .... ...................................................................................... .................................................................................. 147 Process Definition........................................................................................ Definition........................................................................................ 148 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 149 Physical Property Models and Data....................................................... Data.... ................................................... 150 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 150 Process Studies................................................................................. Studies.... ............................................................................. 151 Selected Simulation Results.......................................................................... Results.......................................................................... 154 References.... References................................................................................................. ............................................................................................. 156 C4 Styrene Ethyl Acrylate Free-Radical Free-Radical Copolymerization Copolymerization Process Process .... ..................... .................157 157 About This Process Process .... ...................................................................................... .................................................................................. 157 Process Definition........................................................................................ Definition........................................................................................ 157 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 158 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 158 Parameter Regression .... ........................................................................ .................................................................... 160 Process Studies................................................................................. Studies.... ............................................................................. 163 Selected Simulation Results.......................................................................... Results.......................................................................... 167 References.... References................................................................................................. ............................................................................................. 171 C5 Styrene Butadiene Emulsion Copolymerization Process .... ................................ ............................172 172 About This Process Process .... ...................................................................................... .................................................................................. 172 Process Definition........................................................................................ Definition........................................................................................ 173 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 173 Physical Property Models and Data....................................................... Data.... ................................................... 175 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 175 Process Studies................................................................................. Studies.... ............................................................................. 176 Selected Simulation Results.......................................................................... Results.......................................................................... 180 References.... References................................................................................................. ............................................................................................. 183 C6 Styrene Butadiene Ionic Polymerization Processes .... ................ ........................ ....................... ........... 184 About This Process Process .... ...................................................................................... .................................................................................. 184 Process Definition........................................................................................ Definition........................................................................................ 185 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 186 Kineti Kinetics cs .... ........................................................................................... 186 Process Studies................................................................................. Studies.... ............................................................................. 187 Selected Simulation Results.......................................................................... Results.......................................................................... 189

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C7 High-Density Polyethylene Polyethylene High Temperature Solution Solution Process Process .... .................... ................192 192 About This Process Process .... ...................................................................................... .................................................................................. 192 Process Definition........................................................................................ Definition........................................................................................ 193 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 193 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 194 Process Studies................................................................................. Studies.... ............................................................................. 194 Selected Simulation Results.......................................................................... Results.......................................................................... 200 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 205 References.... References................................................................................................. ............................................................................................. 210 C8 Low-Density Polyethylene High Pressure Process .... ................. .......................... ........................ ........... 211 About This Process Process .... ...................................................................................... .................................................................................. 211 Process Definition........................................................................................ Definition........................................................................................ 211 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 213 Physical Property Models and Data....................................................... Data.... ................................................... 214 Process Studies................................................................................. Studies.... ............................................................................. 215 Selected Simulation Results.......................................................................... Results.......................................................................... 219 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 222 References.... References................................................................................................. ............................................................................................. 228 C9 Nylon 6 Caprolactam Polymerization Polymerization Process.... Process............... ........................ .......................... .................... ....... 230 About This Process Process .... ...................................................................................... .................................................................................. 230 Process Definition........................................................................................ Definition........................................................................................ 231 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 232 Physical Property Models and Data....................................................... Data.... ................................................... 233 Reaction Kinetics............................................................................... Kinetics............................................................................... 233 Process Studies................................................................................. Studies.... ............................................................................. 239 Selected Simulation Results.......................................................................... Results.......................................................................... 244 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 245 References.... References................................................................................................. ............................................................................................. 248 C10 Methyl Methacrylate Methacrylate Polymerization in Ethyl Ethyl Acetate .... .................................. ..............................249 249 About This Process Process .... ...................................................................................... .................................................................................. 249 Process Definition........................................................................................ Definition........................................................................................ 249 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 250 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 251 Process Studies................................................................................. Studies.... ............................................................................. 251 Selected Simulation Results.......................................................................... Results.......................................................................... 253 References.... References................................................................................................. ............................................................................................. 258 C11 Polypropylene Gas Phase Polymerization Processes .... ................................... ...............................259 259 About This Process Process .... ...................................................................................... .................................................................................. 259 Process Definition........................................................................................ Definition........................................................................................ 260 Process Process Condit Conditions ions .... ............................................................................ ........................................................................ 261 Physical Property Models and Data....................................................... Data.... ................................................... 263 Reactors Reactors / Kinetics Kinetics .... ............................................................................ ........................................................................ 263 Process Studies................................................................................. Studies.... ............................................................................. 264 Selected Simulation Results.......................................................................... Results.......................................................................... 269 Simulation Simulation Stream Summary Summary .... .............................................................. .......................................................... 269 References.... References................................................................................................. ............................................................................................. 277

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Inde Index x .... ................ ........................ ........................ ......................... ......................... ........................ ........................ ........................ ......................... ............. 278

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Introducing Aspen Polymers Plus

Aspen Polymers Plus is a general-purpose process modeling system for the simulation of polymer manufacturing processes. processes. The modeling system includes modules for the estimation of thermophysical properties, and for performing polymerization kinetic calculations and associated mass and energy balances. Also included in Aspen Polymers Plus are modules for: •

Characterizing polymer molecular structure

•

Calculating rheological and mechanical properties

•

Tracking these properties throughout a flowsheet

There are also many additional features that permit the simulation of the entire manufacturing processes. This casebook is a compilation of simulation examples, user models, and industrial application examples. Note: Some of the simulations described in this book require Fortran files. These are found in the same location as the simulation files (\xmp or \app sub-directory of the GUI installation directory). You must compile the accompanying Fortran before running the files.

About This Manual The Aspen Polymers Plus Examples & Applications Casebook is divided into three sections: •

Section A – Simulation Examples provides step-by-step instructions for using Aspen Polymers Plus® to build and use a polymer process simulation model. Topics include: o

Creating a simulation model

o

Predicting physical properties

o

Regressing property parameters

o

Fitting kinetic parameters

o

Fractionating oligomers

o

Calculating end-use properties


1

•

•

Section B – User Models provides step-by–step instructions for using and customizing currently available User2 models. Topics include: o

Four-phase equilibrium TP-Flash

o

Polymer fractionation algorithm

o

User-specified molecular weight distribution for feed streams

o

Aspen Polymers Plus – Predici interface

Section C – Application Examples presents common industrial processes and describes how to simulate the reactor section of specific polymer production processes. A few of the application examples describe a complete plant flowsheet, and others focus on physical property representation. Topics include: o

Polystyrene bulk polymerization by thermal initiation

o

Polystyrene with styrene monomer distillation

o

Expanded polystyrene suspension polymerization

o

Styrene ethyl acrylate free-radical copolymerization process

o

Styrene butadiene emulsion copolymerization process

o

Styrene butadiene ionic polymerization processes

o

High-density polyethylene high temperature solution process

o

Low-density polyethylene high pressure process

o

Nylon 6 caprolactam polymerization process

o

Methyl methacrylate polymerization in ethyl acetate

o

Polypropylene gas phase polymerization processes

Note: Dynamic process applications are available in the Aspen Dynamics™ Examples documentation set.

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Related Documentation In addition to this document, a number of other documents are provided to help users learn and use Aspen Polymers Plus applications. The documentation set consists of the following:

Installation Guides Aspen Engineering Suite Suite Installation Guide

Aspen Polymers Plus Guides Aspen Polymers Plus User Guide, Volume 1 Aspen Polymers Plus User Guide, Volume 2 (Physical Property Methods & Models) Models )

Aspen Plus Guides Aspen Plus User Guide Aspen Plus Getting Started Started Guides

Aspen Dynamics Guides Aspen Dynamics Examples Aspen Dynamics User User Guide Aspen Dynamics Reference Guide

Technical Support AspenTech customers with a valid license and software maintenance agreement can register to access the online AspenTech Support Center at: http://support.aspentech.com This Web support site allows you to: •

Access current product documentation

•

Search for tech tips, solutions and frequently asked questions (FAQs)

•

Search for and download application examples

•

Search for and download service packs and product updates

•

Submit and track technical issues

•

Send suggestions

•

Report product defects

•

Review lists of known deficiencies and defects


3

Registered users can also subscribe to our Technical Support e-Bulletins. These e-Bulletins are used to alert users to important technical support information such as: •

Technical advisories

•

Product updates and releases

Customer support is also available by phone, fax, and email. The most up-todate contact information is available at the AspenTech Support Center at http://support.aspentech.com.. http://support.aspentech.com

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A1 Creating a Simulation Model

This example describes how to construct a polymer simulation model. It provides an overview of Aspen Polymers Plus features. The steps covered include: •

Creating a New Run

•

Creating the Process Flowsheet

•

Specifying Setup and Global Options

•

Specifying Components

•

Characterizing Polymers

•

Specifying Physical Properties

•

Specifying Feed Streams

•

Specifying Kinetics

•

Defining the Unit Operation Block

•

Running the Simulation

•

Examining Simulation Results

•

Plotting Distributions

•

Creating Live Distribution Plots

•

Pasting and Linking Between Aspen Polymers Plus and Excel

•

Saving the Run and Exiting

The process in this example uses two CSTR reactors and a mixer. The freeradical kinetics occur in the reactors.

Creating a New Run To construct the simulation model you need to start Aspen Polymers Plus. To start Aspen Polymers Plus: 1

Start Aspen Plus from the Start Menu or by double clicking the Aspen Plus icon on your desktop. The Aspen Plus Startup dialog box appears.


5

2

On the Aspen Plus Startup dialog box, click the Template option. Click OK. OK. The New dialog box appears. You use this dialog box to specify the simulation template and Run Type for the new run. Aspen Plus uses the Simulation Template you choose to automatically set various defaults appropriate to your application.

3

For this example, click Polymers with Metric Units for your template. The default Run type, type, Flowsheet, is appropriate. Click OK. OK. The Aspen Plus main window is now active.

Creating the Process Flowsheet In a flowsheet you can: •

Place (or delete) blocks

•

Place (or delete) streams

•

Rename blocks and streams

The process flowsheet for this example is shown here.

Placing Blocks and Streams Follow these instructions to: •

Place unit operation blocks

•

Place streams and connect blocks

To place unit operation blocks:

6

1

In the Model Library, click the Reactors tab, then the RCSTR icon. RCSTR icon.

2

Move the mouse to the Process Flowsheet window, then click to place block B1.

3

In the Process Flowsheet window, click to place the second RCSTR block, B2.

4

In the Model Library, click the Mixers/Splitters tab, then the Mixer icon.


If you want to select different Mixer model icons, click the down-arrow on the icon. To place streams: 1

Click the Material STREAMS icon on the left corner of the Model Library and move the mouse to the Process Flowsheet window. Red and blue arrows appear on the unit operation blocks. These arrows indicate the location of the required (red) and optional (blue) stream connection ports.

2

Place the “+” cursor on the red feed arrow of B1 and click to make the connection. Move the mouse away from the block and click again to place stream 1 (FEEDA).

3

Place the “+” cursor on the red product arrow of B1 and click to make the connection. Move the mouse to the red feed arrow of B3 (M) and click again to connect the two blocks. Refer to the process flowsheet for the location of these streams.

4

Repeat these steps to create a feed stream for B2, connect B2 and B3 (M), and create a product stream for B3 (M).

5

After placing all streams, turn off the insert mode by clicking the Select Mode button

in the upper left corner of the Model Library.

Renaming Blocks and Streams To rename blocks and streams: 1

Click the block to be renamed, such as B3, and click the right mouse button to display the menu.

2

Click Rename Block. Block.

3

Enter the Block ID as “M” and click OK. OK.

4

Click the stream to be renamed, such as 1, and click the right mouse button to display the menu.

5

Click Rename Stream. Stream.

6

Enter the Stream ID as “FEEDA” and click OK. OK.

7

Repeat these steps to rename the other streams.

You are now ready to enter input data for your simulation.

Specifying Setup and Global Options To enter process and model specifications into Aspen Polymers Plus, you can use the Next button or the Data Browser Menu Tree. In this example, you enter data using the Menu Tree. Use the Setup folder to: •

Enter a simulation title

•

Define unit-sets


7

•

Review and specify global options set by the simulation template you selected

Entering a Simulation Title To enter a title: 1

From the Data menu, click Setup. Setup. The Setup Specifications - Data Browser appears.

2

On the Global sheet, type the title of your simulation run as:

Creating an Aspen Polymers Plus Simulation Model

Defining Unit-Sets This example requires a user defined unit-set for input data and output results. To define a unit-set: 1

From the Setup folder in the Menu Tree, double-click the Units-Sets subfolder.

2

Click New to create a new set.

3

Enter an ID (for example, SET1) and click OK. OK. A dialog box appears requesting approval to make SET1 the global unit set, click Yes. Yes.

4

Confirm that SI is entered in the Copy from field. If it is not selected, select SI from the pulldown list. This means the simulation will use SI units as the basis for your new unit set.

5

Set the following options: o

Mass Flow = kg/hr

o

Mole Flow = kmol/hr

o

Temperature = C

o

Pressure = atm

Entering a Simulation Description A Description sheet is available to enter a more detailed description of the simulation. To enter the description for this example: 1

From the Setup folder in the Menu Tree, click the Specifications form.

2

Click the Description tab. You can either retain or delete the default information displayed, but type the following description: This example describes how to put together a polymer simulation model.

8


Defining Report Options Since you chose the Polymers with Metric Units simulation template when you started this example, Aspen Plus has set defaults for calculating and reporting stream properties: •

No mole flow

•

Mass flow

To enter a user defined stream report format: 1

From the Setup folder in the Menu Tree, click the Report Options form.

2

Click the Stream tab.

3

In addition to the default options, click Mole for the Flow basis frame and Mass for the Fraction basis frame.

Specifying Other Simulation Options To enter other simulation options for this example: 1

From the Setup folder in the Menu Tree, click the Simulation Options form.

2

Click the Limits tab.

3

Enter 1000 in the Simulation time limit in CPU seconds field.

4

Click the System tab, and click the Print Fortran tracebacks when a Fortran error occurs option.

Specifying Components You use Components forms to select chemical components for your simulation and specify component types (for example, conventional, solid, assay, blend, polymer, segment, oligomer, and pseudocomponent). To select components: 1

From the Data menu, click Components. Components.

2

On the Selection sheet, enter the components as shown:


9

Characterizing Polymers You must enter additional characterization characterization information for segments, polymers, oligomers and site-based species. You must also define the type of segments present. Segments can be repeat units, end groups, or branch points attached to three or four branches. To define the segments: 1

From the Components folder in the Menu Tree, double-click the Polymers sub-folder.

2

From the Polymers sub-folder, click the Characterization form.

3

On the Segments sheet, from the Type pulldown list, click REPEAT for segments STYSEG and ACNSEG.

For each polymer you must define the component attributes to be tracked. All components specified as type Polymer in the Specifying Components section require component attributes. To specify component attributes for the polymers: 1

Click the Polymers tab.

2

Verify SAN appears in the Polymer ID pulldown list, or select it if it does not appear.

3

In the Built-in attribute group field, click Free-radical selection from the pulldown list. The attribute summary table, Attribute list, list, is automatically filled in. You can click the cells in the attribute list table or click Edit to change the selections.

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To track distributions in your simulation in order to generate plots or tables, you need to specify the type of distribution, the polymer, and the display characteristics for the generated distribution data. To request a distribution: 1

From the Menu Tree, click the Distributions form.

2

On the Selection sheet, from the Polymer ID pulldown list, click SAN.

Specifying Physical Properties To define global physical property methods: 1

In the Menu Tree, doubl-click the Properties folder.

2

From the Properties folder, click Specifications. Specifications.

3

On the Global sheet, in the Base method field, click POLYNRTL.

User defined property parameters such as molecular weight for polymers are defined in the Properties folder: 1

From the Properties folder in the Menu Tree, double-click the Parameters sub-folder.

2

In the Parameters sub-folder, click the Pure Component folder.

3

Click New. New. The New Pure Component Parameters dialog box appears.

4

Verify Scalar is selected, and in the Enter new name or accept default field enter DATA1 as new name for parameter. Click OK. OK.

5

From the Parameters pulldown list, click MW. MW.

6

Enter the molecular weights for the components: AIBN=164.0 AIBN=164.0 and SAN=104.150. SAN=104.150.


11

Specifying Feed Streams To enter stream specifications, you either open input forms from the Data Browser Menu Tree, or select a stream on the Process Flowsheet window and use the right mouse button to open the stream menu, where you click Input to open the input form. Here, you use the Menu Tree. To enter feed stream specifications: 1

From the Menu Tree, double-click the Streams folder.

2

From the Streams folder, double-click the FEEDA sub-folder.

3

From the FEEDA sub-folder, click Input. Input. On the Specifications sheet, enter:

12

o

Temperature =70 °C

o

Pressure =2 atm

o

Total Flow (Mass) = 24000 kg/hr

o

Composition = Mass Frac

•

AIBN = 0.002

•

EB = 0.002

•

STY = 0.25

•

ACN = 0.25

•

XYLENE = 0.496

4

From the Menu Tree, double-click the FEEDB sub-folder. Click Input. Input.

5

On the Specifications sheet, enter: o

Temperature =70 C

o

Pressure =2 atm

o

Total Flow (Mass) = 24000 kg/hr

o

Composition = Mass Frac

•

AIBN = 0.004

•

STY = 0.1

•

ACN = 0.4


•

XYLENE = 0.496

Specifying Kinetics Kinetic inputs are specified in the Reactions folder. This example uses the free-radical kinetics model. To specify the free-radical polymerization inputs: 1

From the Menu Tree, double-click the Reactions folder.

2

From the Reactions folder, click the Reactions sub-folder.

3

Click New to create a new reaction.

4

In the Enter ID field, type R1, in the Select type field, select FREERAD. RAD. Click OK. OK.

5

On the Species sheet, enter information as shown:

Be sure to click the Generate Reactions option to generate reactions automatically from the list of reacting species. 6

Click the Comments button to add the description "Grade A SAN polymerization kinetics." Click OK. OK.

Modifying Reactions To review and edit the reactions: 1

Click the Reactions tab. An Auto Generation dialog box appears.

2

Click Yes to turn off reaction generation.

3

On the Reactions sheet, review the automatically generated reactions and delete any unnecessary equations by selecting them in the table and clicking the Delete button reactions for:


. For this example, you can delete all

13

4

o

Chat-agent

o

Chat-sol

o

Term-dis

Click the Rate Constants button. The Rate Constant Parameters form appears.

5

Click the Summary tab and enter reaction rate constants as shown for each reaction:

Tip: To move directly to the Rate Constant Summary sheet, in step 4, click the Rate Constants tab.

Note: You can also refer to the Input Summary REACTIONS paragraph for R1 on page 21 for the rate constants of R1. 6

After entering the data, click Close. Close.

7

To verify you have entered data correctly, click the first reaction in the table, then click the Rate Constants button The Rate Constant Parameters sheet for the first reaction should look like this:

14


8

Click Close. Close.

Specifying Gel Effect To specify Gel effect: 1

Click the Options tab to specify additional simulation options for the model. Click Gel effect. effect.

2

Click the Gel Effect tab.

3

From the No. pulldown list, click New. Note: To enter data in the No. field you can also use the right mouse button to click in the field, then click Create from the menu.

1

Enter the information for the gel effect correlation as shown:


15

Repeat the above procedures for Specifying Kinetics, Kinetics, Modifying Reactions, Reactions, and Specifying Gel Effect to specify the kinetics for R2. Refer to the Input Summary REACTIONS paragraph for R2 on page 21 for the appropriate comment, reactions, rate constants, and gel-effect correlations.

Defining the Unit Operation Block You must define the operating conditions for unit operations.

Entering Block Specifications To enter block specifications for the CSTR reactors: 1

From the Menu Tree, double-click the Blocks folder.

2

From the Blocks folder, double-click the B1 sub-folder.

3

Click Setup, Setup, and on the Specifications sheet enter: o

Pressure =2 atm

o

Temperature =70 C

o

Valid Phases = Liquid-Only

o

Reactor Volume = 10 cum

4

Click the Reactions tab.

5

Click R1, then the button to move it from the Available Reaction Sets to the Selected Reaction Sets frame. This defines R1 as the reaction set that describes the chemical reactions occurring in B1.

6

7

16

Click the Component Attr. tab and set: o

Substream ID = MIXED

o

Component ID = SAN

Enter a series of Attribute of Attribute ID and Component Attribute values as below: o

Attribute ID = LPFRAC Component Attribute value = 1E-005

o

Attribute ID = LEFRAC Component Attribute values = 0.5, 0.5

o

Attribute ID = LSFRAC Component Attribute values = 0.5, 0.5

o

Attribute ID = LDPN Component Attribute value = 500

o

Attribute ID = SFRAC Component Attribute values = 0.5, 0.5

o

Attribute ID = PDI Component Attribute value = 1.5

o

Attribute ID = DPN Component Attribute value = 1000


Improving Convergence Polymer reaction kinetics present very difficult convergence problems, so the standard convergence options are frequently insufficient. To resolve this problem, we use the RCSTR block Convergence form. To do this: 1

From Blocks folder, B1 sub-folder in the Menu Tree, click the Convergence form.

2

Click the Parameters tab and change the Solver to Newton. Newton.

3

Click Newton Parameters and change the Stabilization Strategy to Line-Search. Line-Search. Click Close. Close.

Note: This combination of parameters (step 2 and step 3) is recommended for all addition polymerization kinetics. 4

From the Parameters sheet, click Advanced Parameters and change the Scaling method to Component-based Component-based..

Note: Component-based scaling is recommended for all Aspen Polymers Plus simulations. 5

Click the Initialize using integration option. When this option is selected, CSTR uses an integrator to provide an initial guess to the simultaneous equation solver.

Overriding Global Values Block Options forms can be used to override global values for physical properties, simulation options, diagnostic message levels and report options. For B1 the control panel diagnostic message level is set higher than the global default value 4. To override values: 1

From Blocks folder, BI sub-folder in the Menu Tree, click the Block Options form.

2

Click the Diagnostics tab, and set the On Screen slider bar to level 7.

Repeat the above procedures for Entering Block Specifications, Specifications , Improving Convergence, Convergence, and Overriding Global Values to define the unit operation block B2. Refer to the Input Summary BLOCKS B2 paragraph on page 20. 20. Note that only the Convergence component values differ from Block B1.

Entering Mixer Specifications To enter Mixer specifications: 1

From the Blocks folder in Menu Tree, double-click the M sub-folder.

2

From the M sub-folder, click Input. Input.

3

On the Flash Options sheet enter: o

Pressure = 1 atm

o

Valid phases = Liquid-Only


17

Running the Simulation To run a simulation: 1

Click the input.

button to confirm that you have finished entering all required

The Required Input Complete dialog box appears. 2

Click OK. OK. A Control Panel appears, and shows the run progress.

Note: You can also open a control panel from the Aspen Plus toolbar, by clicking the

button, then the

button.

As the run proceeds, status messages appear in the Control Panel. Panel. When the calculations are complete, the message Results Available appears in the status bar at the right corner of the Aspen Plus main window.

Examining Simulation Results When the message Results Available appears in the status bar you can examine your simulation results. To examine the results: 1

From the Menu Tree, double-click the Results Summary folder.

2

In the Results Summary folder, click Run Status. Status. The Summary sheet appears. The Aspen Plus version, run starting time and run status are summarized on this sheet.

3

From the Results Summary folder, click Streams. Streams. The Material sheet appears with the stream results.

Since you selected the Polymers with Metric Units Simulation Template, POLY_M is used as the stream result format and reports stream Temperature, Pressure, Average MW, and other results. Mass Flow, and Mass Fraction are reported based on the selections made in the Specifying Setup and Global Options section on page 7. You can click the scroll bar to review the stream results that are off the screen.

18


You select Results from the pulldown list between the use the 1

and

buttons and

button to navigate to the next form with results.

After reviewing the Material sheet, and selecting Results from the pulldown list, click the

button.

The Poly. Curves sheet appears. You can review the polymer structural property distribution results for the streams. 2

Click the

button.

The Stream FEEDA Results form appears. 3

Use the

button to review the remainder of the results.

Input Summary The input summary for this example is shown here: TITLE 'Creating an Aspen Polymers Plus Simulation Model' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C PDROP='N/sqm'

&

DEF-STREAMS CONVEN ALL SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=1000.0 DESCRIPTION " This example describes how to put together a polymer simulation model. " DATABANKS PURE11

/ POLYMER

PROP-SOURCES PURE11


/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

19

COMPONENTS AIBN C8H8 / EB C8H10-4 / STY C8H8 / ACN C3H3N / XYLENE C8H10-3 / STYSEG C8H8-R / ACNSEG C3H3N-R / SAN SAN FLOWSHEET BLOCK B1 IN=FEEDA OUT=GRADEA BLOCK B2 IN=FEEDB OUT=GRADEB BLOCK M IN=GRADEA GRADEB OUT=PRODUCT PROPERTIES POLYNRTL PROP-DATA DATA1 IN-UNITS SI PROP-LIST MW PVAL AIBN 164.0 PVAL SAN 104.150 POLYMERS SEGMENTS STYSEG REPEAT / ACNSEG REPEAT POLYMERS SAN ATTRIBUTES SAN DPN DPW PDI MWN MWW ZMOM FMOM SMOM SFLOW & SFRAC LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW LEFRAC & LPFRAC DISTRIBUTION SAN CHAIN-SIZE NPOINTS=100 UPPER=100000. STREAM FEEDA SUBSTREAM MIXED TEMP=70.0 PRES=2.0 MASS-FLOW=24000.0 MASS-FRAC AIBN .0020 / EB .0020 / STY .250 / ACN .250 / & XYLENE .4960 STREAM FEEDB SUBSTREAM MIXED TEMP=70.0 PRES=2.0 MASS-FLOW=24000.0 MASS-FRAC AIBN .0040 / STY .10 / ACN .40 / XYLENE & .4960 BLOCK M MIXER PARAM PRES=1.0 NPHASE=1 PHASE=L BLOCK B1 RCSTR PARAM VOL=10. TEMP=70.0 PRES=2.0 NPHASE=1 PHASE=L SCALING=COMPONENTS ALGORITHM=MIXED CONVERGENCE SOLVER=NEWTON STAB-STRAT=LINE-SEARCH BLOCK-OPTION TERM-LEVEL=7 REACTIONS RXN-IDS=R1 BLOCK B2 RCSTR PARAM VOL=10. TEMP=70.0 PRES=2.0 NPHASE=1 PHASE=L SCALING=COMPONENTS ALGORITHM=MIXED CONVERGENCE SOLVER=NEWTON STAB-STRAT=LINE-SEARCH BLOCK-OPTION TERM-LEVEL=7

20

&

&


REACTIONS RXN-IDS=R2 EO-CONV-OPTI CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC REACTIONS R1 FREE-RAD DESCRIPTION "Grade A SAN Polymerization Kinetics" PARAM SPECIES INITIATOR=AIBN MONOMER=STY ACN CHAINTAG=EB & SOLVENT=XYLENE POLYMER=SAN MON-RSEG STY STYSEG / ACN ACNSEG INIT-DEC AIBN .00003710 0.0 0.0 CHAIN-INI STY 4820.0 0.0 0.0 CHAIN-INI ACN 225.0 0.0 0.0 PROPAGATION STY STY 4820. 0.0 0.0 PROPAGATION STY ACN 10277. 0.0 0.0 PROPAGATION ACN STY 7165.6 0.0 0.0 PROPAGATION ACN ACN 225. 0.0 0.0 CHAT-MON STY STY 0.289 0.0 0.0 CHAT-MON STY ACN 0.289 0.0 0.0 CHAT-MON ACN STY .0060 0.0 0.0 CHAT-MON ACN ACN .0060 0.0 0.0 TERM-COMB STY STY 13900000. 0.0 0.0 TERM-COMB STY ACN 358000000. 0.0 0.0 TERM-COMB ACN STY 358000000. 0.0 0.0 TERM-COMB ACN ACN 10200000. 0.0 0.0 GEL-EFFECT TERMINATION 2 MAX-PARAMS=10 GE-PARAMS=1.0 0.0 2.570 -.005050 9.560 -.01760 -3.030 .007850 0.0 2.0 REACTIONS R2 FREE-RAD DESCRIPTION "Grade B SAN Polymerization Kinetics" PARAM SPECIES INITIATOR=AIBN MONOMER=STY ACN CHAINTAG=EB & SOLVENT=XYLENE POLYMER=SAN MON-RSEG STY STYSEG / ACN ACNSEG INIT-DEC AIBN 3.71E-005 0.0 0.0 EFFIC=1.0 NRADS=2 CHAIN-INI STY 4820.0 0.0 0.0 CHAIN-INI ACN 225.0 0.0 0.0 PROPAGATION STY STY 4820.0 0.0 0.0 PROPAGATION STY ACN 10277.0 0.0 0.0 PROPAGATION ACN STY 7165.60 0.0 0.0 PROPAGATION ACN ACN 225.0 0.0 0.0 CHAT-MON STY STY .2890 0.0 0.0 CHAT-MON STY ACN .2890 0.0 0.0 CHAT-MON ACN STY .0060 0.0 0.0 CHAT-MON ACN ACN .0060 0.0 0.0 TERM-COMB STY STY 1.3900E+08 0.0 0.0 TERM-COMB STY ACN 3.5800E+09 0.0 0.0 TERM-COMB ACN STY 3.5800E+09 0.0 0.0 TERM-COMB ACN ACN 1.0200E+08 0.0 0.0 GEL-EFFECT TERMINATION 2 MAX-PARAMS=10 GE-PARAMS=1.0 0.0 2.570 -.005050 9.560 -.01760 -3.030 .007850 0.0 2.0


&

&

21

Plotting Distributions Follow these instructions to: •

Display and plot the distribution data for a polymerization reactor

•

Display a distribution table for a stream or an entire flowsheet

To display and plot the distribution data for a polymerization reactor: 1

From the Blocks folder B1 sub-folder in the Menu Tree, click the Results form.

2

Click the Distributions tab.

3

From the Aspen Plus menu bar, click Plot, Plot, then Plot Wizard. Wizard. The Aspen Plus Plot Wizard appears.

4

Click Next, Next, then the icon for Chain Size Distr. plot type.

5

Click Next. Next. If you want to review further plot options, click Next, Next, or proceed directly to the next step.

6

Click Finish. Finish. The plot is displayed.

Note: You can modify the plot by using the right mouse button to click the objects in the plot window. From the menu, click Edit, Edit, Properties, Properties, or Modify to make necessary changes. To display a distribution table for a stream or for the entire flowsheet: 1

From the Menu Tree, double-click the Results Summary folder.

2

Click the Streams form.

3

Click the Poly. Curves tab. You may need to use the scroll arrows to locate the tab.

4

From the Aspen Plus menu bar, click Plot, Plot, then Plot Wizard. Wizard.

5


6

Click Next. Next.

7

Click the stream(s) you want to plot from the Available box and click the button to move them to the Selected box. In this example, all streams are selected. If you want to review further plot options, click Next, Next, or proceed directly to the next step.

8

Click Finish. Finish. The plot appears.

22


Creating Live Distribution Plots The distribution plotting capability lets you create live plots that are automatically refreshed when you rerun the simulation. To create a live distribution plot for a reactor: 1


2


3

From the Aspen Plus menu bar, click Plot, Plot, then Plot Wizard. Wizard.

4


5

Click Next. Next.

6

Verify the Show average properties option is selected. Click it if it is not selected.

7

Click Next. Next.

8

To update the plot when new results are available, click Yes in the bottom left corner of the Plot Wizard. Wizard.

Note: To activate this feature when the plot window is active, from the Aspen Plus menu bar, click Edit, Edit, then Live Plot. Plot. 9

Click Finish. Finish. The plot appears.


23

You are now ready to make another simulation and see the plot change. To change the specifications for B1: 1

Keeping the plot window on your screen, from the Blocks folder B1 subfolder in the Menu Tree, click the Setup form.

2

On the Specifications sheet, change temperature to 5 °C and reactor volume to 70 cum.

3

To rerun the simulation, click the

button.

Watch the distribution curve and average properties change in the plot window.

Viewing Plots for Multiple Simulations To manually superimpose distribution plots for several simulations you need to: •

Prepare your current plot

•

Select axis values

•

Add the new data to plot

To clear the existing plot values:

24


1

Click to make the plot window active. From the Aspen Plus menu bar, click Edit, Edit, then Live Plot. Plot. This turns off the feature.

2

Click the average property text (DPN, DPW, PDI) on the plot, click the right mouse button, then Delete. Delete. Click OK. OK.

3

From the Blocks folder B1 sub-folder in the Menu Tree, click the Setup form.

4

On the Specifications sheet, change temperature back to 70 °C and reactor volume to 10 cum.

5

To run the simulation, click the change.

button. This time the plot does not

To manually select x-axis and y-axis values for the plot: 1


2


3

You are going to manually select the x-axis values and y-axis values for the new plot. Click DPn to select the degree of polymerization column as the x-axis.

4

From the Aspen Plus menu bar, click Plot, Plot, then X-Axis Variable. Variable. DPn is set as the x-axis.

5

On the Distributions sheet, click Mass frac. to select the mass fraction column as the y-axis.

6

From the Aspen Plus menu bar, click Plot, Plot, then Y-Axis Variable. Variable. Mass fraction is set as the y-axis.

To superimpose the new data on the plot: 1

From the Aspen Plus menu bar, click Plot, Plot, then Add New Curve. Curve.

2

To choose the plot on which the new curve should be superimposed, in the Plot Window List dialog box, click B1: Chain Length Distribution. Distribution.

3

Click OK. OK. The plot window shows two superimposed curves, with separate y-axes.


25

To use a single y-axis, use the right mouse button to click a curve line, then click Properties from the menu. The Plot Control Properties dialog box appears. 4

Click the AxisMap tab.

5

Click the All in One button, then click Apply. Apply. You can use the Legend tab to change the legend for the new plot and define the reactor conditions.

Pasting and Linking Between Aspen Polymers Plus and Excel You use OLE linking to establish connections between Aspen Plus and other applications. To paste and link the distribution table of B1 to an Excel application: 1

From the the Blocks folder B1 sub-folder in the Menu Tree, click Results. Results.

2

Click the Distributions tab, then use the right mouse button to click DPn. DPn. The column of data is highlighted.

3

On the menu, click Copy. Copy .

4

Open an Excel work sheet and type DPn as the title of the first column. With the mouse curse over the second row, use the right mouse button to click in the cell. On the menu, click Paste Special. Special.

5

On the Paste Special dialog box, click Paste Link, Link, click Text, Text, and click OK.

6

Repeat the same steps for the Mass frac. column.

The distribution table is generated in Excel and is updated when the simulation results change in Aspen Plus. To obtain reaction rate constants from Excel:

26

1

Open an Excel file containing the reaction rate constant parameters.

2

Use the right mouse button to select a column of reaction constants, such as Pre-Exp (ko), and from the menu, click Copy. Copy .


3

In Aspen Plus, from the Reactions folder in the Menu Tree, click R1. R1.

4

Click the Reactions tab.

5

Click Parameters and click the Summary tab on the Rate Constant Parameters dialog box.

6

Place the cursor in the top cell use the right mouse button to click the Pre-Exp column, click Paste Special. Special.

7

Click the Paste Link option and click the Text option.

The reaction constants are copied to Aspen Plus and are updated when changes are made in Excel.

Saving the Run and Exiting Before you exit Aspen Plus, you may save the run as a Backup file (*.bkp) or a Quick Restart file (*.apw). It is recommended that you use the backup file format to save disk space and for future version compatibility. To save an .apw and a .bkp file: 1

From the Aspen Plus menu bar, click File, File, then Save As. As.

2

Enter a file name, then click .apw or .bkp in the Save as type field. Click Save to apply.

To exit Aspen Plus: 1

From the Aspen Plus menu bar, click File, File, then Exit. Exit.

2

A dialog box appears asking if you want to save the run, select Yes if you have not saved the run.

Congratulations! You have just built and run a complete polymerization example using Aspen Polymers Plus.


27

A2 Predicting Physical Properties

This example demonstrates how to use Aspen Polymers Plus to predict pure component properties of polymers using the Van Krevelen group contribution method. The steps covered include: •

Defining the Simulation

•

Creating a New Run

•


•

Specifying and Characterizing Components

•


•

Defining Molecular Structure

•

Specifying Mass Fraction Crystallinity

•

Creating Property Sets

•

Creating Property Tables

•

Running the Simulation and Examining the Results

The Van Krevelen method is based on the chemical structure of the polymers (Van Krevelen, 1990) . It uses additive molar functions based on group contribution. Using this technique a variety of polymer properties can be predicted. In Aspen Polymers Plus, the Van Krevelen method i s used to estimate heat capacity of both liquid and solid polymers, liquid viscosity and thermal conductivity for both polymer melt and polymer solution, and density. In this example, heat capacity, thermal conductivity, and density are predicted at atmospheric pressure in the temperature range of 20 to 500°C for poly (2,6 dimethyl phenylene oxide). Since this temperature range crosses the glass point and melting point of the polymer we will see predictions for liquid and solid polymer. In this example, we consider the polymer of 2,6 dimethyl phenol, which can polymerize through an oxidative coupling reaction to form a type of poly(phenylene oxide), an aromatic polyether. The structure of the repeat unit of this polymer is:

28


*

O

*

The repeat segment considered in this example is not available in the Aspen Polymers Plus databanks. Therefore, the properties of the segment are estimated using Van Krevelen group contribution methods, by providing the groups constituting this segment. Property tables and property sets are used to tabulate liquid heat capacity, heat capacity and density of the polymer.

Defining the Simulation In this example, you apply the Property Analysis feature to estimate the properties of a polymer over a range of temperatures. When using property analaysis or physical property data regression, the polymer components must be defined as oligomers. oligomers. This provides a mechanism through which the structure of the molecule can be defined without using polymer component attributes. In this example we consider purely amorphous polymer and a polymer with 40% mass crystallinity. These two types of polymer are defined as PPO-A and PPO-40. The resulting component list for this simulation run is: Component Type

Name

Formula

PPO-A

OLIGOMER

PPO-40

OLIGOMER

POLY(PHENYLENE-OXIDE)

PPO

PPO-REP

SEGMENT

POLY(PHENYLENE-OXIDE)

PPO

The feed stream consists of 1 kg/hr of styrene, 1 kg/hr of n-butyl-acrylate and 1 kg/hr of the copolymer at one atmosphere pressure and 500 K. The feed is flashed at 500 K and 1 atm.

Creating a New Run To start Aspen Polymers Plus: 1


2

On the Aspen Plus Startup dialog box, click the Template option. Click OK. OK. The New dialog box appears. You use this dialog box to specify the simulation template and Run Type for the new run.

3

For this example, click Polymers with Metric Units for your template.

4

Change the Run type to Property Analysis. Analysis.

5

Click OK. OK. The Aspen Plus main window is now active.


29

Note: For convenience, you may wish to change the default units set to use temperature in degree C. You are now ready to enter input data for your simulation.

Specifying Setup and Global Options To enter process and model specifications into Aspen Polymers Plus, you can use the Next button enter data using

or the Data Browser Menu Tree. In this example, you button.

To enter a title and description for the simulation: 1

From the Aspen Plus toolbar, click the

button.

The Setup Specifications - Data Browser appears. 2

On the Global sheet, type the title of your simulation run as: Estimate properties of poly(2,6 dimethyl phenoxide)

3

Click the Description tab. You can either retain or delete the default information displayed, but type the following description: Estimate properties of 2,6-DM PPO using Van Krevelen group contribution methods.

4

Click

.

A Component Specifications Selection sheet appears.

Specifying and Characterizing Components You use Components forms to select chemical components for your simulation and specify component types (for example, conventional, solid, assay, blend, polymer, segment, oligomer, and pseudocomponent). To specify and characterize components: 1

30

On the Component Specifications Selection sheet, enter the Component ID, ID, Type, Type, Component name, name, and Formula for monomers, segments and copolymer as shown:


Note: For the segment PPO-REP, the name and formula slots are left empty because as part of this exercise you will provide molecular structure for this segment. 2

Click

.

A Components Polymers Characterization form appears. 3

On the Segments sheet, from the Type pulldown list, click REPEAT to define PPO-REP as a repeat segment.

4

Click the Oligomers tab.

5

From the Segment pulldown list, click PPO-REP. PPO-REP.

6

For each oligomer component, enter the number of repeat segments in the table:

Note: In this example, the number of segments in the oligomer is arbitrary since none of the properties being evaluated depend on the chain length. In general, however, the number of segments should be set equal to the expected number average degree of polymerization of the polymer. The weight average degree of polymerization can be specified indirectly by entering the POLPDI unary property parameter for each oligomer component. 7

Click

.

A Properties Specifications Global sheet appears.

Specifying Physical Properties To specify physical properties: 1

On the Properties Specifications Global sheet, from the Base method pulldown list, click POLYNRTL.

2

Click

.

A Required Properties Input Complete dialog box appears. 3

Click OK. OK.


31

Defining Molecular Structure To define the molecular structure for the segment PPO-REP:

32

1

From the Properties folder in the Menu Tree, click the Molecular Structure sub-folder.

2

In the Object manager, manager, click the name PPO-REP and click Edit. Edit.

3

Click the Functional Group tab.

4

From the Method pulldown list, click VANKREV (Van Krevelen) method.

5

Enter the Group number and Number of occurrences as shown:


Note: The structure of the repeat unit is divided into groups:

*

O

Group 118

Group 149

Specifying Mass Fraction Crystallinity The crystallinity of the polymer may be specified using the POLCRY pure component property parameter. To do this: 1

From the Properties folder in the Menu Tree, double click the Parameters sub-folder.

2

Click the Pure Component sub-folder.

3

On the Object manager, manager, click New. New. A New Pure Component Parameters dialog box appears.

4

To enter a scalar parameter, click OK. OK.

5

On the Input tab, enter the oligomer component, property parameter and mass fraction crystallinity as shown:

Creating Property Sets To list desired polymer properties, you need to create property sets and property tables. To do this: 1

From the Properties folder in the Menu Tree, click the Prop-Sets subfolder.

2

In the Object manager, manager, click New. New. A Create new ID dialog box appears


33

3

To accept the name PS-1, click OK. OK.

4

On the Properties sheet, from the Physical properties and Units pulldown lists, enter: o

CP (heat capacity) in J/kg-K

o

K (thermal conductivity) in W/m-K

o

RHO (density) in kg/cum

o

TM (melting point) in C

o

TG (glass transition temperature) in C

Your form should look like this:

5

Click the Qualifiers tab.

6

From the Phase pulldown list, click Liquid

7

In the Component row, enter PPO-A and PPO-40 in the first two columns.

Note: In Aspen Polymers Plus, the Liquid identifier is also used to refer to all types of solid polymer in the mixed substream. The property models switch equations (for liquid, glassy, crystalline, or amorphous polymer) depending on the temperature and the predicted transition temperatures.

Creating Property Tables To create property tables: 1

From the Properties folder in the Menu Tree, click the Analysis subfolder.

2

In the Object manager, manager, click New. New. The Create new ID dialog box appears.

34

3

From the Select type pulldown list, click GENERIC and accept PT-1 as the ID by clicking OK. OK.

4

On the System sheet, click the Specify Component Flow option and enter 1 for each oligomer component.

5

Click the Variable tab, and for Fixed State Variables, Variables, enter a pressure of 1 atm.


6

From the Variable pulldown list, click Temperature. Temperature.

7

Click the Range/List button. The Adjusted Variable Range/List Options dialog box appears.

8

From the Variable range or list pulldown list, click Range and enter 25C to 500C with Increments of 25. Click Close. Close.

9

Click the Tabulate tab, and click PS-1, PS-1, then click the it to Selected Prop-Sets. Prop-Sets.

button to move

Your simulation is now complete.

Running the Simulation and Examining the Results Follow these instructions to: •

Run the simulation

•

Examine the results

To run the simulation: 1

From the Aspen Plus toolbar, click

.

The Control Panel appears. 2

To run the simulation, click

.

As the run proceeds, status messages appear in the Control Panel. Panel. When the calculations are complete, the message Results Available appears in the status bar at the right corner of the Aspen Plus main window. To examine the results: 1

From the Menu Tree, double-click the Results Summary folder. The Summary sheet appears.

2

From the pulldown list between the

3

Click

and

buttons, click Results. Results.

to navigate to the next form with results.

The following figures show selected results for heat capacity, thermal conductivity and density. Note that the polymer goes through glass transition at 210°C and melts at 397°C. Above the melting point, the crystallinity is ignored so both components show the same predictions.


35

0 5 7 2

Heat Capacity

0 0 5 2 K - 0 g 5 2 k / 2 J A C - 0 T 0 A 0 2 E H S 0 S 5 A 7 1 M

LIQUID CP PPO-A LIQUID CP PPO-40

0 0 5 1

0

50

36

150

200

250 TEMP C

300

350

400

450

500

Thermal Conductivity

3 . 0 9 2 . 0 8 2 . 0 7 2 . 0 6 2 . K - 0 m 5 / t t 2 . a 0 W 4 2 . D 0 N O 3 C . - 2 L 0 A 2 2 M . 0 R E 1 H 2 . T 0 2 . 0 9 1 . 0 8 1 . 0 0

100

Semi-Crystalline

LIQUID K PPO-A LIQUID K PPO-40

Liquid Glassy Solid

50

100

150

Amorphous Solid

200 250 300 Temperature, deg C

350

400

450

500


0 0 1 1

Density

LIQUID RHO PPO-A

0 5 0 1

LIQUID RHO PPO-40

0 0 0 1 m u c / g k Y 0 T 5 I S 9 N E D S S 0 A 0 9 M

0 5 8

0

50

100

150

200

250 TEMP C

300

350

400

450

500

Input Summary The input language summary for this example is shown here:

TGS DYNAPLUS DPLUS RESULTS=ON TITLE 'Estimate properties of poly( 2,6 dimethyl

phenoxide ) '

IN-UNITS SI PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' DESCRIPTION " Estimate properties of 2,6-DM PPO using Van Krevelen group contribution methods. " DATABANKS POLYMER

/ SEGMENT

PROP-SOURCES POLYMER

/ PURE12

/ SEGMENT

/ NOASPENPCD

/ PURE12

COMPONENTS PPO-A PPO / PPO-40 PPO / PPO-REP PROPERTIES POLYNRTL STRUCTURES VANKREV PPO-REP 118 1 / 149 1 PROP-DATA PURE-1 IN-UNITS SI PRESSURE=atm TEMPERATURE=C PDROP='N/sqm'


37

PROP-LIST POLCRY PVAL PPO-40 0.4 POLYMERS SEGMENTS PPO-REP REPEAT OLIGOMERS PPO-A PPO-REP 100. / PPO-40 PPO-REP 100. PROP-SET PS-1 CP K RHO TM TG UNITS='J/kg-K' 'Watt/m-K' 'kg/cum' 'C' SUBSTREAM=MIXED PHASE=L

&

PROP-TABLE PT-1 FLASHCURVE MASS-FLOW PPO-A 1. / PPO-40 1. STATE PRES=1. VARY TEMP RANGE LOWER=25. UPPER=500. INCR=25. TABULATE PROPERTIES=PS-1

References Van Krevelen, D. W. (1990). Properties of Polymers, Polymers , 3rd Ed. Amsterdam: Elsevier.

38


A3 Regressing Property Parameters

This example demonstrates how to use the data regression (DRS) capabilities to fit the mixture parameters of an equation of state (EOS) model to binary vapor-liquid equilibrium (VLE) data. The steps covered include: •


•

Creating a New Run

•


•


•

Specifying Physical Property Method

•

Entering Experimental Data

•

Specifying a Regression Case

•

Specifying Physical Property Parameters

•


Correlative models used to describe thermodynamic properties of mixtures often contain binary interaction parameters. These parameters account for mixture non-idealities, and are necessary for accurate representation of the mixture behavior. For each constituent pair of a multicomponent mixture, these parameters are obtained by regressing some form of binary experimental information. In this example, binary VLE data of ethylene-polyethylene mixture is regressed to obtain the two binary interaction parameters of the Sanchezand . You can find the details of this model in Volume 2 Lacombe EOS, of the Aspen the Aspen Polymers Plus User Guide. Guide. Ethylene-polyethylene binary mixture is encountered in polyolefin production, and at high pressures the thermodynamic behavior of this mixture can be described by an EOS such as the Sanchez-Lacombe model.


39

Defining the Simulation In this example, you create an Aspen Polymers Plus data regression (DRS) session, run the DRS, and examine the results.



2


3

For this example, click Polymers with Metric Units for your template.

4

From the Run type pulldown list, click Data Regression

5




User the Setup folder to: •

Enter simulation title and description

•

Define unit-sets

Entering a Simulation Title and Description To enter a title and description for the simulation: 1


.


On the Global sheet, type the title of your simulation run as: Regression of binary parameters for the POLYSL model

3

In the Units of measurement field, for Input data and Output results, results , click SI. SI.

4

Click the Description tab. You can either retain or delete the default information displayed, but type the following description: The objective of this example is to demonstrate how to use the data

40


regression capabilities to fit the mixture parameters of an EOS model to binary VLE data.

Defining Unit-Sets To define a unit-set: 1

From the Setup folder in the Menu Tree, click the Units-Sets sub-folder.

2

Click New. New.

3

To accept US-1 as the unit set ID, click OK. OK. A dialog box appears requesting approval to make US-1 the global unit set

4

Click No No..

5

On the Standard sheet, from the Copy from pulldown list, click Eng. Eng.

6


Temperature = K

o

Pressure = bar

7

Click the Transport tab

8

From the Density pulldown list, click kg/cum. kg/cum .

9

Repeat these steps to create unit set US-3 (step 3) in which: o

Copy from=SI (step 5)

o

Pressure=bar (step 6)

o

Delta P=bar (step 6)

10 Click

.


Specifying and Characterizing Components The component information necessary for this DRS run is: Component ID

Type

Component Name

Formula

PE

Oligomer

POLY(ETHYLENE)

PE

ETHYLENE

Conventional

ETHYLENE

C2H4

C2H4-R

Segment

ETHYLENE-R

C2H4-R

In this example, the polymer is identified as oligomer. This is required for property data regresssion and property analysis runs. By defining the polymer as an oligomer, the need to enter any attribute information is eliminated. The composition (segment fractions) and the number-average chain length and moleuclar weight of the polymer are determined from the structure defined in the oligomer form. To avoid a warning message, you need to supply the true molecular weight of t he oligomer as described in the Specifying Physical Property Parameters section on page 46 46.. However, the results of the DRS run are not affected by the reference molecular weight specified in the property parameters section. To supply the component information for this example:


41

1

On the Component Specifications Selection sheet, enter the Component ID, ID, Component name, name, and Formula for ethylene, polyethylene and ethylene segment as shown:

2

From the Components folder in the Menu Tree, click the Polymers subfolder.

3

On the Segments sheet, from the Type pulldown list, click REPEAT. REPEAT.

4

Click the Oligomers tab, select C2H4-R as the segment and enter 1132 for PE in the oligomer row.

5

Click

.

The Properties Specifications Global sheet appears.

Specifying Physical Property Method The Sanchez-Lacombe model physical property method (POLYSL) is used in this example. To choose this method: 1

On the Properties Specifications Global sheet, from the Base method pulldown list, click POLYSL.

2

Click

.

An Information dialog box appears. 3

Click OK. OK. The Properties Data form appears.

Entering Experimental Data The experimental data used in this DRS run is from Hao and coauthors, and is provided in the appropriate steps of this procedure (Hao, Elbro, & Alessi, 1992). To enter the experimental data: 1

42

In the Object manager, manager, click New. New.


2

Enter ID as C2PE399 (for data at 399K), and from the Select type pulldown list, click MIXTURE. MIXTURE.

3

Click OK. OK. A Properties Data Setup sheet for C2PE399 appears.

4

Enter: o

Category = Phase equilibrium

o

Component basis = Mass Fraction

o

Data type = TPXY

A Change Data Type dialog box appears, click OK. OK. 5

From Available Components, Components, click ETHYLENE and click to Selected Components. Components.

6

Repeat step 5 for PE. PE.

7

Click the Constraints tab. You need to delete PE from the Component column since PE is considered involatile in t his example. Use the right mouse button to click PE, then click Clear. Clear.

8

Click the Data tab, enter: o

Temperature = K

o

Pressure = kPa

o

Overwrite standard deviation as:

•

Temperature = 0

•

Pressure = 1%

•

Mole fraction = .001

•

Enter the data at 399.15K from Hao et al. (1992).

to move it

Usage

Temp., K

Pressure, KPA

X, Ethylene

X, PE

STD-DEV

0

1%

.001

0

DATA

399.15

455.8

.0018

0.9982

DATA

399.15

790.30

.0037

0.9963

DATA

399.15

1135

.0055

0.9945

DATA

399.15

1479

.0075

0.9925

DATA

399.15

1824

.0107

0.9893

DATA

399.15

2168

.0136

0.9864

DATA

399.15

2513

.0158

0.9842

DATA

399.15

2857

.0175

0.9825

DATA

399.15

3202

.0198

0.9802

DATA

399.15

3546

.0221

0.9779

DATA

399.15

3891

.0242

0.9758

DATA

399.15

4235

.0255

0.9745

DATA

399.15

4580

.0285

0.9715

DATA

399.15

4924

.0305

0.9695

DATA

399.15

5269

.0330

0.967

DATA

399.15

5613

.0359

0.9641

After the first four entries, your data sheet should look like this:


43

9

44

From the Properties folder in the Menu Tree, click the Data folder and repeat the steps to enter the data from Hao et al. (1992) at 413.15K and 428.15K. Usage

Temp., K

Pressure, KPA

X, Ethylene

X, PE

STD-DEV

0

1%

.001

0

DATA

413.15

455.8

.0015

0.9985

DATA

413.15

790.30

.0034

0.9966

DATA

413.15

1135

.0048

0.9952

DATA

413.15

1479

.0068

0.9932

DATA

413.15

1824

.0087

0.9913

DATA

413.15

2168

.0112

0.9888

DATA

413.15

2513

.0131

0.9869

DATA

413.15

2857

.0151

0.9849

DATA

413.15

3202

.0166

0.9834

DATA

413.15

3546

.0189

0.9811

DATA

413.15

3891

.0208

0.9792

DATA

413.15

4235

.0235

0.9765

DATA

413.15

4580

.0250

0.975

DATA

413.15

4924

.0277

0.9723

DATA

413.15

5269

.0296

0.9704

DATA

413.15

5613

.0328

0.9672

DATA

428.15

455.8

.0013

0.9987

DATA

428.15

790.30

.0029

0.9971

DATA

428.15

1135

.0039

0.9961

DATA

428.15

1479

.0055

0.9945

DATA

428.15

1824

.0074

0.9926

DATA

428.15

2168

.0090

0.991

DATA

428.15

2513

.0105

0.9895

DATA

428.15

2857

.012

0.988

DATA

428.15

3202

.0146

0.9854

DATA

428.15

3546

.0164

0.9836

DATA

428.15

3891

.0178

0.9822


Usage

Temp., K

Pressure, KPA

X, Ethylene

X, PE

DATA

428.15

4235

.0207

0.9793

DATA

428.15

4580

.0222

0.9778

DATA

428.15

4924

.0242

0.9758

DATA

428.15

5269

.0265

0.9735

DATA

428.15

5613

.0286

0.9714

10 Click

.

A Regression Cases Incomplete dialog box appears.

Specifying a Regression Case To specify a regression case: 1

On the Regression Cases Incomplete dialog box, click Specify the data regression cases.

2

Click OK. OK.

3

Click New. New.

4

To accept R-1, click OK. OK.

5

Click the Parameters tab, enter the Initial value, value, Lower bound, bound, and other options as shown:

Note: Note: The binary parameters may be specified for the oligomer-conventional species pair or for the segment-conventional species pair. For homopolymers either approach is suitable. For copolymers, the segment approach offers greater flexibility to account for the influence of polymer segmental composition on phase equilibrium. 6

Click

.

A Required Properties Input Complete dialog box appears.


45

Specifying Physical Property Parameters To specify physical property parameters: 1

On the Required Properties Input Complete dialog box, click Enter property parameters option.

2

Click OK. An Additional property parameters dialog box appears.

3

To accept the Pure Component Parameters option, click OK. OK.

In the Sanchez-Lacombe model, for each component, three pure component constants, T *, *, P *, *, and ρ* are needed. To enter these pure component constants: 1

In the Properties Parameters Pure Component form, click New.

2

In the lower right corner of New of New Pure Component Parameters dialog box, enter PCES-1 as the new name.

3

To accept the Scalar option, click OK. OK.

4

On the Input sheet, click US-1 from the toolbar units-set pulldown list, enter the other information as shown:

Note: These constants are reported in Appendix E of the Aspen Polymers Plus User Guide, Guide, Volume 2. Unary parameters are entered for segment of the polymer, rather than the polymer itself.

46

5

From the Properties folder Parameters sub-folder in the Menu Tree, click the Pure-Component sub-folder.

6


7

In the lower right corner of New of New Pure Component Parameters dialog box, enter MW as the new name.

8


9

On the Input sheet, click US-3 from the toolbar units-set pulldown list, enter the other information as shown:


Note: It is necessary to identify a polymeric molecule when the oligomer option is used.


Run the simulation

•

Examine the results


Click

.

A Required Properties Input Complete dialog box appears. 2

Click OK. OK. A Required Data Regression Input Complete dialog box appears.

3

Click OK. OK. A Data Regression Run Selection dialog box appears.

4

To accept R-1 as the run selection, click OK. OK. The Control Panel appears and the simulation starts running.

5

When the Parameter Values dialog box appears, click Yes to all to replace the existing parameters with the regressed values.

When you see the message Data Regression completed, completed, the results are present. To examine the results: 1


2


3

Click

and




47

Input Summary The input summary for this example is shown here:

TITLE 'Regression of binary parameters for the POLYSL model' IN-UNITS SI DESCRIPTION " The objective of this example is to demonstrate how to use the data regression capabilities to fit the mixture parameters of an EOS model to binary VLE data. " DATABANKS POLYMER

/ SEGMENT


/ PURE12

/ SEGMENT

/ NOASPENPCD

/ PURE12

COMPONENTS ETHYLENE C2H4 ETHYLENE / PE PE PE / C2H4-R C2H4-R C2H4-R PROPERTIES POLYSL PROP-DATA MW IN-UNITS SI PRESSURE=bar PDROP=bar PROP-LIST MW PVAL PE 31756.8563 PROP-DATA PCES-1 IN-UNITS ENG DENSITY='kg/cum' PRESSURE=bar TEMPERATURE=K PDROP=psi PROP-LIST SLPSTR / SLRSTR / SLTSTR PVAL C2H4-R 4250 / 887 / 673 PVAL ETHYLENE 3339 / 660 / 291

&

PROP-DATA SLETIJ-1 IN-UNITS SI PROP-LIST SLETIJ BPVAL PE ETHYLENE -.4040175320 BPVAL ETHYLENE PE -.4040175320 PROP-DATA SLKIJ-1 IN-UNITS SI PROP-LIST SLKIJ BPVAL PE ETHYLENE -.0900000000 BPVAL ETHYLENE PE -.0900000000 PARAMETERS BIPARAMETER 1 SLKIJ PE ETHYLENE 1 1.00000000E-02 & -9.00000000E-02 1.10000000E-01 1.00000000E+00 BIPARAMETER 2 SLETIJ PE ETHYLENE 1 -9.00000000E-02 & -9.90000000E-01 8.10000000E-01 1.00000000E+00 CASE R-1

48


DATA-GROUPS C2PE399 CONSISTENCY=YES / C2PE413 CONSISTENCY=YES / C2PE428 CONSISTENCY=YES PARAMETERS BINARY=1 2

&

DATA-GROUP C2PE399 IN-UNITS SI PRESSURE=kPa PDROP='N/sqm' SYSTEM-DEF TPXY ETHYLENE PE COMPOSITION=MASS-FRAC PHASE-EQ VL ETHYLENE DATA 1 399.15 455.8 .0018 1 / 2 399.15 790.30 .0037 1 / 3 399.15 1135 .0055 1 / 4 399.15 1479 .0075 1 / 5 399.15 1824 .0107 1 / 6 399.15 2168 .0136 1 / 7 399.15 2513 .0158 1 / 8 399.15 2857 .0175 1 / 9 399.15 3202 .0198 1 / 10 399.15 3546 .0221 1 / 11 399.15 3891 .0242 1 / 12 399.15 4235 .0255 1 / 13 399.15 4580 .0285 1 / 14 399.15 4924 .0305 1 / 15 399.15 5269 .0330 1 / 16 399.15 5613 .0359 1 STD-DEV 1 0 -1 .001 -1 DATA-GROUP C2PE413 IN-UNITS SI PRESSURE=kPa PDROP='N/sqm' SYSTEM-DEF TPXY ETHYLENE PE COMPOSITION=MASS-FRAC PHASE-EQ VL ETHYLENE DATA 1 413.15 455.8 .0015 1 / 2 413.15 790.30 .0034 1 / 3 413.15 1135 .0048 1 / 4 413.15 1479 .0068 1 / 5 413.15 1824 .0087 1 / 6 413.15 2168 .0112 1 / 7 413.15 2513 .0131 1 / 8 413.15 2857 .0151 1 / 9 413.15 3202 .0166 1 / 10 413.15 3546 .0189 1 / 11 413.15 3891 .0208 1 / 12 413.15 4235 .0235 1 / 13 413.15 4580 .0250 1 / 14 413.15 4924 .0277 1 / 15 413.15 5269 .0296 1 / 16 413.15 5613 .0328 1 STD-DEV 1 0 -1 .001 -1 DATA-GROUP C2PE428 IN-UNITS SI PRESSURE=kPa PDROP='N/sqm' SYSTEM-DEF TPXY ETHYLENE PE COMPOSITION=MASS-FRAC PHASE-EQ VL ETHYLENE DATA 1 428.15 455.8 .0013 1 / 2 428.15 790.30 .0029 1 / 3 428.15 1135 .0039 1 / 4 428.15 1479 .0055 1 / 5 428.15 1824 .0074 1 /


49

6 428.15 2168 .0090 1 / 7 428.15 2513 .0105 1 / 8 428.15 2857 .012 1 / 9 428.15 3202 .0146 1 / 10 428.15 3546 .0164 1 / 11 428.15 3891 .0178 1 / 12 428.15 4235 .0207 1 / 13 428.15 4580 .0222 1 / 14 428.15 4924 .0242 1 / 15 428.15 5269 .0265 1 / 16 428.15 5613 .0286 1 STD-DEV 1 0 -1 .001 -1 POLYMERS SEGMENTS C2H4-R REPEAT OLIGOMERS PE C2H4-R 1132 PROPERTY-REP NOPCES PROP-DATA DFMS

References Hao, W., Elbro, H. S., & Alessi, P. (1992). Polymer Solution Data Collection. Collection . Chemistry Data Series, XIV , Part 1, DECHEMA.

50


A4 Fitting Kinetic Parameters

This example demonstrates how to fit kinetic rate constant parameters to available data for a single reactor flowsheet. This example describes the basic procedure for developing a simulation to fit kinetic parameters. The steps covered include: •


•

Creating a New Run

•


•


•


•


•

Specifying Polymerization Kinetics

•

Supplying Process Information

•

Specifying Data Regression

•


The Styrene Ethyl Acrylate Free-Radical Copolymerization Process application example in Section C provides strategies for fitting parameters for complex systems. In this process, vinyl acetate is polymerized in solution in a batch reactor with methanol as a solvent and methyl peroxide as the initiator. The reactor is operated isothermally with the polymerization temperature maintained at the boiling point of methanol, 64.7°C, 1 atm. The reactor is considered liquid filled. Therefore, vapor-liquid equilibrium calculations are not accounted for in this simulation. In practice, there is usually some vapor space in the reactor and reflux condenser. This has some effect on the concentration in the liquid phase. However, the effect is not considered significant for this homopolymerization example. The simulation can be modified to include VLE calculations if necessary. The component information is: Component ID Type MPO


Component Name

Conventional VINYL-ACETATE

Formula C4H6O2-1

51

VAC

Conventional VINYL-ACETATE

C4H6O2-1

MEOH

Conventional METHANOL

CH4O

POLY

Polymer

POLY(VINYL-ACETATE)

PVAC

VAC-SEG

Segment

VINYL-ACETATE-R

C4H6O2-R-3 C4H6O2-R-3

The feed stream consists of 100 kg/hr of vinyl acetate, 80 kg/hr of methanol, 0.0258 kg/hr of initiator at one atmosphere and 64.7°C. The initial charge is determined by multiplying the flowrates by the cycle time needed to prepare the charge.

Defining the Simulation This example demonstrates how to fit kinetic rate constant parameters to available data for a single reactor flowsheet.



2


3

For this example, click Polymers with Metric Units for your template. The default Run type, type, Flowsheet, is appropriate for this example.

4




•


•


The process flowsheet for this example is shown here:

52

A4 Fitting Kinetic Parameter Parameters s



•


To place unit operation blocks: 1

In the Model Library, click the Reactors tab, then the RBatch icon. If you want to select different RBatch model icons, click the down-arrow on the icon.

2

Move the mouse to the Process Flowsheet window, then click to place the block (BATCH).

To place streams: 1


2

Place the “+” cursor on the red feed arrow and click to make the connection. Move the mouse away from the block and click again to place stream 1 (FEED).

3

Repeat step 2 to create the product stream.

4



Renaming Blocks and Streams To rename blocks and streams: 1

Click the block to be renamed, B1, and click the right mouse button to display the menu.

2

Click Rename Block. Block.

3

Enter the Block ID as “BATCH” and click OK. OK.


53

4

Click the stream to be renamed, such as 1 (FEED), and click the right mouse button to display the menu.

5


6

Enter the Stream ID as “FEED” and click OK. OK.

7

Repeat steps 4-6 to rename the PRODUCT stream.




User the Setup folder to: •

Enter simulation title and description

•

Define unit-sets

•

Review and specify other global simulation options



.


On the Global sheet, type the title of your simulation run as: Free-Radical Kinetics Parameter Fitting

3

Click the Description tab. You can either retain or delete the default information displayed, but type the following description: This example illustrates how to fit kinetic rate constant parameters in Aspen Polymers Plus.



2

Click New. New.

3

To accept US-1 as the unit set ID, click OK. OK. A dialog box appears requesting approval to make US-1 the global unit set

4

Click Yes. Yes.

5

On the Standard sheet, from the Copy from pulldown list, click SI. SI.

6

Set the following options:

Mass Flow = kg/hr Mole Flow = kmol/hr Pressure = atm

54


Temperature = C 7

Click

.


Specifying and Characterizing Components To specify and characterize components: 1

On the Component Specifications Selection sheet, enter the Component ID, ID, Component name, name, and Formula for monomers, segments and copolymer as shown:

2

Click

3

On the Segments sheet, from the Type pulldown list, click REPEAT to define VAC-SEG as a repeat segment.

4

Click the Polymers tab, from the Built-in attribute group pulldown list, click Free-radical selection. selection.

5

To modify the attribute group, click Edit. Edit.

6

On the Polymer Attributes dialog box, click to clear the attributes that do not appear below.

.


55

7

Click Close. Close.

8

Click

.

A Properties Specifications Global form appears.

Specifying Physical Properties Follow these instructions to: •

Specify physical properties

•

Enter pure component parameters

•

Enter a Prop-Set

•

Display a Prop-Set in a stream report

To specify physical properties: •

On the Properties Specifications Global form, from the Base Base method pulldown list, click POLYNRTL. POLYNRTL.

Defining Pure Component Parameters To enter pure component parameters: 1

From the Properties folder in the Menu Tree, double-click the Parameters sub-folder.

2

Click the Pure Component sub-folder.

3


4

In the lower right corner of New of New Pure Component Parameters dialog box, enter DATA-1 as the new name.

5


6

On the Input sheet, in the Parameters cell, click to select MW from the pulldown list. For Component, Component, enter: Component

56

MW


MPO

76.050

Defining a Prop-Set To enter a Prop-Set: 1


2

In the Object Manager, Manager, click New. New.

3

Enter DENSITY as the new name of the property set. Click OK. OK.

4

On the Properties tab, click in the Physical properties cell to select RHO, click the Units cell to select kg/cum. Repeat this step to select RHOMX, with units of kg/cum.

5

Click the Qualifiers tab from the Phase pulldown list, click and Liquid. Liquid.

6

From the pulldown lists in the Component row, click to select VAC, POLY, and MEOH.

Defining the Stream Report To display the Prop-Set in the stream report: 1


2

Click the Stream tab.

3

Click the Property Sets button, click DENSITY, and click

to move it

to Selected Property Sets. Sets . 4

Click Close. Close.

Specifying Polymerization Kinetics To specify polymerization kinetics: 1

From the Menu Tree, double-click the Reactions. Reactions.

2

From the Reactions folder, click the Reactions sub-folder.

3


4

In the Enter ID field, type REAC-1, and from the Select Type pulldown list click FREE-RAD. FREE-RAD. Click OK. OK.

5

On the Species sheet, enter the data as shown:


57

6

Click the Reactions tab, enter the data as shown:

To do this for the first reaction: o

Click New. New.

On the Add Reaction dialog box, enter: •

Reaction type = INIT-DEC

•

Initiator = MPO for the

7

58

o

Click Done.

o

Repeat these steps for the other 6 reactions using the information shown.

On the Reactions form, click the Rate Constants button. Click the Summary tab and enter the following rate information: Type

Pre-Exponential (1/s)

Activation Energy (J/kmol)

Initiator Decomposition

5.0E-6

0


Type

Pre-Exponential (1/s)

Activation Energy (J/kmol)

Chain Initiation

9500

0

Propagation

1000

0

Chain Transfer to Monomer

2.337

0

Chain Transfer to Polymer

1.235

0

Chain Transfer to Solvent

0.323

0

Termination by disproportionation 1.645E8

8

0

Click Close. Close.

Specifying Gel-Effect To specify gel effect: 1

Click the Options tab, and click the Gel Effect option.

2

Click the Gel Effect tab.

3

From the No. pulldown list, click New. New.

Note: To enter data in the No. field you can also use the right mouse button to click in the field, then click Create from the menu. 4

Enter the information for the gel effect correlation as shown:

Supplying Process Information Follow these instructions to: •

Enter feed stream information

•

Enter block information

•

Set block convergence and user information


59

Specifying Stream Conditions To enter feed stream information: 1


2

From the Streams folder, click the FEED sub-folder.

3

On the Specifications sheet, enter the stream conditions as:

4

o

Temperature = 64.7°C

o

Pressure = 1 atm

o

MPO = 0.028 kg/hr

o

VAC = 100 kg/hr

o

MEOH = 80 kg/hr

Click

.

Specifying Block Conditions To enter block information: 1

On the Specifications sheet, from the Reactor operating specification pulldown list, click Constant temperature.

2

Enter: o


o

Pressure = 1 atm

The Reactor field already displays Liquid-only. Liquid-only. 3

Click the Reactions tab, click REAC-1, and click Selected reaction sets frame.

4

Click the Stop Criteria tab, enter:

5

o

Criterion No. =1

o

Location = Reactor

o

Variable type = Time

o

Stop value = 5

to move it to the

Click the Operation Times tab, enter: o

Total cycle time =1 hr

o

Maximum calculation time = 5 hr.

o

Time interval between profile points = 0.5 hr

o

Maximum number of profile points = 52

Defining Block Convergence To set convergence and user information for the block:

60

1

From the Menu Tree Blocks folder BATCH sub-folder, click the Convergence form.

2

Click the Integration Loop tab, enter: o

Integration convergence tolerance = 1E-6

o

Initial step size of integration variable = 1E-7

o

Maximum step size of integration variable = 0.1 hr.


3

From the Menu Tree Blocks folder BATCH sub-folder, click the User Subroutine form.

4

In the Values for parameters frame, enter:

5

o

Integer = 100

o

Real = 21000

Click the User Variables tab, and in the Number of user variables field, enter 1.

Specifying Data Regression Follow these instructions to: •

Specify data regression

•

Create multiple data sets

•

Define the regression cases

•

Define the block convergence sequence

To specify data regression: 1

From the Menu Tree, double-click the Model Analysis Tools folder.

2

Double-click the Data Fit folder.

3

Click the Data Set sub-folder. You will need to create two data sets: one named D-INITIA and one named D-PROPAG.

Creating Data Sets To create the first data set: 1

In the Object manager, click New.

2

In the Enter ID field, enter D-INITIA, D-INITIA, and in the Select Type field, click to select PROFILE-DATA. PROFILE-DATA. Click OK. OK.

3

On the Define sheet, enter the data as shown (where MFINIT is the mass fraction of the initiator):


61

4

Click the Data tab, enter a Std-Dev of 1.0 and from the Time pulldown list, click hr. hr.

5

Enter the time and mass fraction data as shown:

6

Data Point

Time (hr)

Mass Fraction of Initiator

1

0.0

1.554E-4

2

0.5

1.551E-4

3

1.0

1.546E-4

4

1.5

1.542E-4

5

2.0

1.538E-4

6

2.5

1.532E-4

7

3.0

1.526E-4

8

3.5

1.522E-4

9

4.0

1.518E-4

10

4.5

1.513E-4

11

5.0

1.509E-4

Click the Initial Conditions tab, enter: o

Temperature = 65 °C

o

Pressure = 1 atm

The Reactor type and Block name fields already display RBATCH and BATCH respectively. To create the second data set: 1

From the Menu Tree Model Analysis Tools folder Data Fit sub-folder, click the Data Set sub-folder.

2


3

In the Enter ID field, enter D-PROPAG, D-PROPAG, and in the Select Type field, click to select PROFILE-DATA. PROFILE-DATA. Click OK. OK.

4

On the Define sheet, enter: o

Variable name = DUTY

o

Variable = DUTY

o

Model and block name = BATCH

RBATCH is already selected as the Block name. name. 5

Click the Data tab, enter a Std-Dev of 5.0. Enter the time and heat release data shown:

62

Data Point

Time (hr)

Instantaneous Heat Release (Watt)

2

0.5

-3750.0

3

1.0

-3700.0

4

1.5

-3300.0

5

2.0

-3250.0

6

2.5

-3100.0

7

3.0

-3000.0

8

3.5

-2800.0

9

4.0

-2650.0


6

10

4.5

-2350.0

11

5.0

-2150.0

Click the Initial Conditions tab, enter: o


o

Pressure = 1 atm

The Reactor type and Block name fields already display RBATCH and BATCH respectively. 7

Click

.

Defining Regression Cases To define the first regression case: 1

On the Data-Fit Regression Cases Incomplete dialog box, click to select Specify Data-Fit Regression Cases. Click OK.

2

From the Menu Tree, click the Regression folder.

3

In the Object manager, manager, click New

4

In the Enter ID field, enter INITA. INITA. Click OK. OK.

5

On the Specifications sheet, from the Data set pulldown list, click DINITIA. INITIA. The Weight is entered as 1.

6

Click the Vary tab, enter:

To define the second regression case: 1

From the Menu Tree Model Analysis Tools folder Data Fit sub-folder, click the Regression sub-folder.

2


3

In the Enter ID field, enter PROPAGA. PROPAGA. Click OK. OK.

4

On the Specifications sheet, from the Data set pulldown list, click DPROPAGA. PROPAGA. The Weight is entered as 1.

5

Click the Vary tab, enter:


63

6

Click the Convergence tab, in the Absolute function tolerance field, enter 1.0.

Defining Block Convergence Sequence To define the block convergence sequence:

64

1

From the Menu Tree, double-click the Convergence folder.

2

From the Convergence folder, click the Sequence sub-folder.

3

In the Object manager, manager, Click New. New.

4

To accept S-1 as the sequence name, click OK. OK.

5

On the Specifications sheet, enter:



Run the simulation

•

Examine the results



.



.



2


3

Click

and



The results for initiation are:

The results for propagation are:


65

Input Summary The input summary for this example is shown here:

TITLE 'Free-Radical Kinetics Parameter Fitting' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C TIME=hr PDROP='N/sqm'

&

DEF-STREAMS CONVEN ALL DESCRIPTION " This example illustrates how to fit kinetic rate constant parameters in Aspen Polymers Plus. " DATABANKS PURE11

/ POLYMER

PROP-SOURCES PURE11

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS MPO C4H6O2-1 / VAC C4H6O2-1 / MEOH CH4O / POLY PVAC / VAC-SEG C4H6O2-R-3 FLOWSHEET BLOCK BATCH IN=FEED OUT=PRODUCT PROPERTIES POLYNRTL PROP-DATA DATA1 IN-UNITS SI PROP-LIST MW

66


PVAL MPO 76.050 POLYMERS SEGMENTS VAC-SEG REPEAT POLYMERS POLY ATTRIBUTES POLY SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM SMOM LSFLOW LEFLOW PROP-SET DENSITY RHO RHOMX UNITS='kg/cum' SUBSTREAM=MIXED COMPS=VAC POLY MEOH PHASE=L

&

&

STREAM FEED SUBSTREAM MIXED TEMP=64.70 PRES=1.0 MASS-FLOW MPO .028 / VAC 100 / MEOH 80 BLOCK BATCH RBATCH USER-VECS NUSER-PROF=1 INT VALUE-LIST=100 REAL VALUE-LIST=21000.0 PARAM TYPE=T-SPEC PRINT-TIME=.5 CYCLE-TIME=1.0 MAX-TIME=5.0 & MAX-NPOINT=52 PRES=1.0 TEMP=64.70 NPHASE=1 PHASE=L & INT-TOL=1.000E-06 HINIT=1.000E-07 INTEG-PARAMS MAXSTEP=.1 STOP 1 REACTOR TIME 5.0 REACTIONS RXN-IDS=REAC-1 REGR-POINTS 1 D-INITIA VALUE-LIST= 0.0 1800.000 3600.000 & 5400.000 7200.000 9000.000 10800.00 12600.00 14400.00 & 16200.00 18000.00 / 2 D-PROPAG VALUE-LIST= 1800.000 & 3600.000 5400.000 7200.000 9000.000 10800.00 12600.00 & 14400.00 16200.00 18000.00 REGR-PARAM MAXPOINT= 11 EO-CONV-OPTI SEQUENCE S-1 BATCH INITIA BATCH (RETURN INITIA) PROPAGA BATCH (RETURN PROPAGA)

&

STREAM-REPOR NOZEROFLOW NOMOLEFLOW MASSFLOW PROPERTIES=DENSITY REACTIONS REAC-1 FREE-RAD DESCRIPTION "EXAMPLE FREE-RADICAL INPUT" PARAM SPECIES INITIATOR=MPO MONOMER=VAC SOLVENT=MEOH POLYMER=POLY MON-RSEG VAC VAC-SEG INIT-DEC MPO 5E-6 .0 .0 CHAIN-INI VAC 9500.0 .0 .0 PROPAGATION VAC VAC 1000.0 .0 .0 CHAT-MON VAC VAC 2.3370 .0 .0 CHAT-POL VAC VAC 1.2350 .0 .0 CHAT-SOL VAC MEOH .3230 .0 .0 TERM-DIS VAC VAC 1.645E+08 .0 .0 GEL-EFFECT TERMINATION 2 MAX-PARAMS=10 GE-PARAMS=1.0 .0 & .44070 .0 6.7530 .0 .34950 .0 .0 1.0 REGRESSION INITIA DATA D-INITIA VARY REACT-VAR REACTION=REAC-1 VARIABLE=IDPRE-EXP


&

67

SENTENCE=INIT-DEC ID1=MPO LIMITS 1E-7 1E-5 ALGORITHM AFCTOL=1.0 INIRIN=0 REGRESSION PROPAGA DATA D-PROPAG VARY REACT-VAR REACTION=REAC-1 VARIABLE=PRPRE-EXP & SENTENCE=PROPAGATION ID1=VAC ID2=VAC LIMITS 1E3 5E4 ALGORITHM AFCTOL=1.0 INIRIN=0 PROFILE-DATA D-INITIA PARAM BLOCK=BATCH TEMP=65.0 PRES=1 UNITS=hr DEFINE ZZTEMP BLOCK-VAR BLOCK=BATCH SENTENCE=PARAM & VARIABLE=TEMP DEFINE ZZPRES BLOCK-VAR BLOCK=BATCH SENTENCE=PARAM & VARIABLE=PRES VECTOR-DEF MFINIT BLOCK-VEC BLOCK=BATCH SENTENCE= & REGR-C-PROF VARIABLE=MASSFRAC-L ID2=MPO USE STD-DEV * -1.0 / DATA 0.0 1.554E-4 / DATA 0.5 & 1.551E-4 / DATA 1.0 1.546E-4 / DATA 1.5 1.542E-4 / & DATA 2.0 1.538E-4 / DATA 2.5 1.532E-4 / DATA 3.0 & 1.526E-4 / DATA 3.5 1.522E-4 / DATA 4.0 1.518E-4 / & DATA 4.5 1.513E-4 / DATA 5.0 1.509E-4 PROFILE-DATA D-PROPAG PARAM BLOCK=BATCH TEMP=64.5 PRES=1 UNITS=hr DEFINE ZZTEMP BLOCK-VAR BLOCK=BATCH SENTENCE=PARAM & VARIABLE=TEMP DEFINE ZZPRES BLOCK-VAR BLOCK=BATCH SENTENCE=PARAM & VARIABLE=PRES VECTOR-DEF DUTY BLOCK-VEC BLOCK=BATCH SENTENCE= REGR-PROF VARIABLE=DUTY USE STD-DEV * 5.0 / DATA 0.5 -3750.0 / DATA 1.0 & -3700.0 / DATA 1.5 -3300.0 / DATA 2.0 -3250.0 / & DATA 2.5 -3100.0 / DATA 3.0 -3000.0 / DATA 3.5 & -2800.0 / DATA 4.0 -2650.0 / DATA 4.5 -2350.0 / & DATA 5.0 -2150.0

68

&


A5 Fractionating Oligomers

This example illustrates the use of Aspen Polymers Plus for modeling a polymer/oligomer fractionation process. The steps covered include: •


•

Creating a New Run

•


•


•


•


•


•


One typical fractionation method is to dissolve the polymer in a good solvent and then add small amounts of antisolvent to it. At the phase equilibria, the high-molecular weight polymer precipitates in the solvent phase, while the lower-molecular weight polymer dissolves in the antisolvent phase. By continuing addition of antisolvent, progressively lower molecular-weight polymer precipitates. The system in this example contains benzene (1, solvent), ethanol (2, antisolvent) and polystyrene (3, polymer). A pseudo-component approach is used to represent the polydispersity of polystyrene. In the pseudo-component approach, a series of oligomers with different degree of polymerization (DP) is defined. The mass distribution of the oligomers in the feed is approximately a Gamma distribution. The Flory-Huggins model of polymer solution is used to calculate the liquid-liquid phase equilibria in this quasi-ternary mixture. The Flory-Huggins binary interaction parameters χ are obtained from Wu and Prausnitz (Wu & Prausnitz, 1990).

Defining the Simulation In this example you create an Aspen Polymers Plus process model to fractionate polystyrene using benzene and ethanol, run the simulation, and examine the results.


69



2


3

For this example, click Polymers with English Units for your template. The default Run type, type, Flowsheet, is appropriate for this example.

4




•


•





•



In the Model Library, click the Separators tab, then the Flash3 icon. If you want to select different Flash3 model icons, click the down-arrow on the icon.

70


2

Move the mouse to the Process Flowsheet window, then click to place the block (B1).

To place streams: 1


2

Place the “+” cursor on the red feed arrow and click to make the connection. Move the mouse away from the block and click again to place stream 1.

3

Repeat step 2 to create the other streams.

4



Renaming Streams To rename streams: 1

Click the stream to be renamed, such as 5, and click the right mouse button to display the menu.

2


3

Enter the Stream ID as “1P” and click OK. OK.


Specifying Setup and Global Options To enter process and model specifications into Aspen Polymers Plus, you can use the Next button or the Data Browser Menu Tree. In this example, you enter data using the Menu Tree. Use the Setup folder to: •

Enter a simulation title

•

Define unit-sets

•

Specify report options


From the Data menu, click Setup. Setup. The Setup Specifications - Data Browser appears.

2

On the Global sheet, type the title of your simulation run as: Polystyrene Oligomer Fractionation

3

Click the Description tab. You can either retain or delete the default information displayed, but type the following description:


71

This example illustrates the use of Aspen Polymers Plus for modeling polymer/oligomer fractionation process.



2

Click New. New.

3

In the Enter ID field, enter SET1, SET1, then click OK. OK. A dialog box appears requesting approval to make SET1 the global unit set

4

Click No No..

5

On the Standard sheet, from the Copy from pulldown list, click Eng. Eng.

6


Pressure = atm

o

Temperature = K

Specifying Report Options To specify report options: 1


2

Click the Stream tab, in the Flow basis frame, click Mole, Mole, and in the Fraction basis frame, click Mole and Mass. Mass.

Specifying and Characterizing Components To specify components:

72

1

From the Menu Tree, double click the Components folder.

2

From the Components folder, click Specifications. Specifications.

3

On the Selection sheet, define benzene, ethanol and ten oligomer components (from OL2 to OL11) as shown:


Note: Styrene segment is needed to define the structure of oligomers. To characterize components: 1

From the Menu Tree Components folder, double-click the Polymers subfolder.

2

In the Polymers sub-folder, click Characterization. Characterization.

3

On the Segments sheet, in the Type field for segment STY-SEG, click REPEAT. REPEAT.

4

Click the Oligomers tab. You need to provide the number of segments for each oligomer. Enter these as shown below using even numbers from 2-20.

Specifying Physical Properties A physical property option set is needed for this simulation. Follow these instructions to: •

Specify physical property method

•

Enter pure component constants

•

Enter binary interaction parameters

•

Select properties to be calculated

•

Display a property sets in a stream report

To specify the global physical property method: 1

From the Menu Tree, double-click the Properties folder.

2

From the Properties folder, click Specifications. Specifications.

3

On the Global sheet, from the Base method pulldown list, click POLYFH. POLYFH.


73

Defining Pure Component Parameters You enter three pure component properties in this example. To enter the first pure component constant: 1

From the Menu Tree Properties folder, double-click the Parameters subfolder.

2

From the Parameters sub-folder, click the Pure Component sub-folder.

3


4

Click to select T-dependent Correlation and expand Liquid vapor pressure to select PLXANT-1. PLXANT-1. Click OK. OK.

5

On the Input sheet, enter data shown in the Input Summary PROP-DATA PLXANT-1 paragraph on page 80. 80. A partial example is shown here:

To enter the second pure component constant:

74

1

From the Menu Tree Properties folder Parameters sub-folder, click the Pure Component folder.

2


3

In the lower right corner of the New Pure component Parameters dialog box, enter the new name as U-3. U-3. Click OK. OK.

4

On the Input sheet, enter the critical constants for oligomers data as shown. Refer to the Input Summary PROP-DATA U-3 paragraph on page 79 for the values of these constants. A partial example is shown here:


5

From the unit field pulldown list on menu bar, click SET1. SET1.

Defining Binary Interaction Parameters To enter binary interaction parameters: 1

From the Menu Tree Properties folder Parameters sub-folder, doubleclick the Binary Interaction sub-folder.

2

From the Binary Interaction sub-folder, click FHCHI-1. FHCHI-1.

3

Enter values as shown below. Refer to the Input Summary PROP-DATA FHCHI-1 paragraph on page 80 for the complete list of parameter values. A partial example is shown here:


75

Defining Properties to be Calculated To select the properties to be calculated: 1

From the Menu Tree Properties folder, click the Prop-Sets sub-folder.

2


3

To accept PS-1 as the new name, Click OK. OK.

4

On the Properties sheet, in the Physical properties field, click GAMMA. GAMMA.

5

Click the Qualifiers tab, from the Phase pulldown list, click Liquid. Liquid.

Defining the Stream Report To display the property set in the stream report: 1


2

Click the Stream tab, and click the Property Sets button.

3

Click PS-1, then click frame. Click Close. Close.

to move it to the Selected property sets

Supplying Process Information Follow these instructions to specify: •

Stream conditions

•

Block specifications

Specifying Stream Conditions To specify the stream condition for the oligomer and non-solvent streams:

76

1


2

From the Streams folder, click the 1 folder.

3

On the Specifications sheet, enter the mass flow and feed condition as follows: o

Temperature = 101.5 F

o

Pressure = 14.7 psi

o

Total flow (Mass) = 2.1 lb/hr

o

Solvent 2 = 2.1 lb/hr

4

From Streams folder in the Menu Tree, click the 1P sub-folder.

5

On the Specifications sheet, enter the data as shown:


Specifying Block Conditions To specify the Flash3 block: 1

From the Menu Tree, double-click the Blocks folder.

2

From the Blocks folder, doubl-click the B1 sub-folder.

3

From the B1 sub-folder, click Input. Input.

4

On the Specifications sheet, enter:

5

o

Temperature = 101.48 F

o

Pressure = 14.7 psi

Click the Key Components tab, from the Key component in the 2nd liquid phase pulldown list, click SOLVENT2. SOLVENT2.


Run the simulation

•

Examine the results



.




.

77



2


3

Click

and



After flashing, the quasi-ternary mixture separates into two liquid phases, a solvent rich phase and an antisolvent rich phase. Using the Flory-Huggins model, the equilibria compositions in solvent and antisolvent phases are computed. The Flory-Huggins predictions for liquid-liquid equilibria of polystyrene-Benzene-Ethanol polystyrene-Benzene-E thanol system are shown here:

78


The solid line is the mass distribution of polystyrene oligomer for the feed stream 1P, dashed lines are for the product streams. When ethanol is added to the polystyrene/benzene mixture, the majority of high molecular weight PS remains in the solvent rich stream while most of the low molecular weight ones dissolve into the antisolvent stream.

Input Summary The input language summary for this example is shown here: TITLE 'Polystyrene Oligomer Fractionation' IN-UNITS ENG DEF-STREAMS CONVEN ALL DESCRIPTION " This example illustrates the use of Aspen Polymers Plus for modeling polymer/oligomer fractionation process. " DATABANKS POLYMER

/ SEGMENT


/ PURE11

/ SEGMENT

/ NOASPENPCD

/ PURE11

COMPONENTS SOLVENT1 C6H6 / SOLVENT2 C2H6O-2 / STY-SEG C8H8-R / OL2 OL3 OL4 OL5 OL6 OL7 OL8 OL9 OL10 OL11 FLOWSHEET BLOCK B1 IN=1 1P OUT=2 3 4 PROPERTIES POLYFH PROP-DATA U-3 IN-UNITS ENG PRESSURE=atm TEMPERATURE=K PDROP=psi PROP-LIST TC / PC / ZC PVAL OL2 500.0 / 20.0 / .20 PVAL OL3 500.0 / 20.0 / .20 PVAL OL4 500.0 / 20.0 / .20 PVAL OL5 600.0 / 20.0 / .20 PVAL OL6 700.0 / 20.0 / .20 PVAL OL7 800.0 / 20.0 / .20 PVAL OL8 850.0 / 20.0 / .20


79

PVAL OL9 900.0 / 20.0 / .20 PVAL OL10 1000.0 / 20.0 / .20 PVAL OL11 1100.0 / 20.0 / .20 PROP-DATA PLXANT-1 IN-UNITS ENG PROP-LIST PLXANT PVAL OL2 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL3 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL4 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL5 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL6 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL7 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL8 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL9 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL10 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL OL11 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PROP-DATA FHCHI-1 IN-UNITS ENG PROP-LIST FHCHI BPVAL SOLVENT1 SOLVENT2 1.7390 0.0 BPVAL SOLVENT1 OL2 .2210 0.0 BPVAL SOLVENT1 OL3 .2210 0.0 BPVAL SOLVENT1 OL4 .2210 0.0 BPVAL SOLVENT1 OL5 .2210 0.0 BPVAL SOLVENT1 OL6 .2210 0.0 BPVAL SOLVENT1 OL7 .2210 0.0 BPVAL SOLVENT1 OL8 .2210 0.0 BPVAL SOLVENT1 OL9 .2210 0.0 BPVAL SOLVENT1 OL10 .2210 0.0 BPVAL SOLVENT1 OL11 .2210 0.0 BPVAL SOLVENT2 OL2 1.4510 0.0 BPVAL SOLVENT2 OL3 1.4510 0.0 BPVAL SOLVENT2 OL4 1.4510 0.0 BPVAL SOLVENT2 OL5 1.4510 0.0 BPVAL SOLVENT2 OL6 1.4510 0.0 BPVAL SOLVENT2 OL7 1.4510 0.0 BPVAL SOLVENT2 OL8 1.4510 0.0 BPVAL SOLVENT2 OL9 1.4510 0.0 BPVAL SOLVENT2 OL10 1.4510 0.0 BPVAL SOLVENT2 OL11 1.4510 0.0 POLYMERS SEGMENTS STY-SEG REPEAT OLIGOMERS OL2 STY-SEG 2 / OL3 STY-SEG 4 / OL4 STY-SEG & 6 / OL5 STY-SEG 8 / OL6 STY-SEG 10 / OL7 STY-SEG & 12 / OL8 STY-SEG 14 / OL9 STY-SEG 16 / OL10 & STY-SEG 18 / OL11 STY-SEG 20 PROP-SET PS-1 GAMMA SUBSTREAM=MIXED PHASE=L STREAM 1 SUBSTREAM MIXED TEMP=101.480003 PRES=14.6959488 MASS-FLOW=2.10 MASS-FLOW SOLVENT2 2.10

80

&


STREAM 1P SUBSTREAM MIXED TEMP=101.480 PRES=14.6959488 MASS-FLOW=1.0 MASS-FRAC SOLVENT1 .708990 / OL2 .020 / OL3 .060 / OL4 & .080 / OL5 .060 / OL6 .040 / OL7 .020 / OL8 .010 & / OL9 .0010 / OL10 .00010 / OL11 .000010 BLOCK B1 FLASH3 PARAM TEMP=101.480003 PRES=14.6959488 L2-COMP=SOLVENT2 STREAM-REPOR MOLEFLOW MASSFLOW MOLEFRAC MASSFRAC PROPERTIES=PS-1

References Wu, A. H., & Prausnitz, J. M. (1990). J. (1990). J. Appl. Pol. Sci ., ., 39, 39, pp. 629-637.


81

A6 Calculating End-Use Properties

This example demonstrates how to use Aspen Polymers Plus to predict important end-use properties including melt-index, intrinsic viscosity and zero-shear viscosity for high-density polyethylene and other polyolefins using user-defined Prop-Set. The steps covered include: •


•

Creating a New Run

•


•


•


•


•


•

Creating a Sensitivity Table

•


The industry uses a number of empirical correlative models to predict melt index of polyethylene product. End-use properties such as melt index are best implemented as a property set (Prop-Set). A number of built-in Prop-Sets are available in Aspen Plus. In addition, Prop-Sets let you specify a property set with add-on user correlations. When doing this, a user-supplied Fortran subroutine is required to perform the calculations. Aspen Polymers Plus supplies a user Prop-Set and the corresponding Fortran subroutine for melt index based on the correlations of Karol, Sinclair, and colleagues, (See the End-Use Properties section in Chapter 2 of the Aspen the Aspen Polymers Plus User Guide, Guide, Volume 1) as well as the intrinsic and zero-shear viscosities (Karol, Brown, & Davison, 1973; Sinclair, 1983).

Defining the Simulation In this example you create an Aspen Polymers Plus process model to predict end-use properties, run the simulation, and examine the results.

82




2


3

For this example, click Polymers with Metric Units for your template. The default Run type, type, Flowsheet, is appropriate for this example.

4




•


•





•



In the Model Library, click the Heat Exchangers tab, then the Heater icon.


83

If you want to select different Heater model icons, click the down-arrow on the icon. 2

Move the mouse to the Process Flowsheet window, then click to place the block (B1).

To place streams: 1


2

Place the “+” cursor on the red feed arrow and click to make the connection. Move the mouse away from the block and click again to place stream 1.

3

Repeat step 2 to create the stream 2.

4





To enter a title and description for the simulation: 1


.


On the Global sheet, type the title of your simulation run as: An example illustrating end-use property calculations

3

Click the Description tab.

4

You can either retain or delete the default information displayed, but type the following description: The objective of this example is to demonstrate how to use Aspen Polymers Plus to predict important end-use properties including meltindex, intrinsic viscosity, and zero-shear viscosity for high-density polyethylene and other polyolefins using user-defined Prop-Sets. This example requires a user Fortran subroutine USRPRP.F. Please copy USRPRP.F from the example directory and compile it in your local directory.

5

Click

.


Specifying and Characterizing Components To specify and characterize components: 1

84

On the Component Specifications Selection sheet, enter the Component ID, ID, Component name, name, and Formula for the segment and polymer as shown:


2

Click

.

3

On the Segments sheet, from the Type pulldown list, click REPEAT. REPEAT.

4

Click the Polymers tab, from the Built-in attribute group pulldown list, click Properties selection. selection.

5

To modify the attribute group, click Edit. Edit.

6

On the Polymer Attributes dialog box, click to select: o

MWW

o

DPW

o

PDI

o

SMOM

7

Click Close. Close.

8

Click

.

A Properties Specifications Global form appears.

Specifying Physical Properties Follow these instructions to: •

Specify physical properties

•

Enter a Prop-Set

To specify physical properties: 1

On the Properties Specifications Global form, from the Base method pulldown list, click POLYFH.

2

From Properties folder in the Menu Tree, double-click the Advanced sub-folder.

3

From the Advanced sub-folder, click User Properties. Properties.

4


5

In the Enter ID field, enter IV as the new name, click OK. OK.

6

On the Specifications sheet, in the User subroutine name field, enter USRPRP.


85

7

Repeat steps 3-6 to enter properties as shown:

Defining a Prop-Set To be able to list desired polymer properties, you need to create property sets and property tables, to do this: To enter a Prop-Set: 1


2

In the Object Manager, Manager, click New. New.

3

In the Enter ID field, enter IV as the new name of the property set. Click OK. OK.

4

On the Properties sheet, click in the Physical properties cell to select IV.

5

Repeat steps 1-4 to create Prop-Sets named MI-K, MI-S and ZVIS (step 3). In step 4, select the corresponding user property name from the Physical properties cell.

6

Click

.

A Required Properties Input Complete dialog box appears.

Supplying Process Information To supply process information: 1

On the Required Properties Input Complete dialog box, click OK. The Stream 1 Input Specifications sheet appears.

2

86

Enter the process information as shown:


3

Click

.

The Component Attr. Sheet appears. 4

From the Attribute ID pulldown menu, click DPN, DPN, in the Value cell, enter 1000.

5

From the Attribute ID pulldown menu, click SFRAC, SFRAC, in the Value cell, enter 1.

6

From the Attribute ID pulldown menu, click PDI, PDI, in the Value cell, enter 3.61

7

Click

.

The BLOCK B1 Input Specifications sheet appears. 8

Enter: o

Temperature = 420K

o

Pressure = 1 atm

Creating a Sensitivity Table To create a sensitivity table: 1

In the Menu Tree, double-click the Model Analysis Tools folder.

2

Click the Sensitivity sub-folder.

3


4

In the Enter ID field, enter END-USE as the ID. Click OK. OK.

5

On the Define sheet, click New. New.

6

In the Enter Variable name field, field, enter IV. Click OK. OK.

7

In the Variable Definition dialog box, select:

8

o

Category = Streams

o

Reference Type = Stream-Prop

o

Stream = 2

o

Prop-Set = IV

Click Close. Close.


87

9

Repeat steps 5-8 to create variables named MIK, MIS and ZVIS (step 6). In step 7, select the corresponding user property name in the Prop-Set field.

10 Click the Vary tab, enter:

11 Click the Tabulate tab, in Column numbers 1-4, enter IV, MI-K, MI-S, and ZVIS respectively. 12 Click the Table Format button, enter:

88


Running the Simulation and Examining the Results Note: This example requires a user subroutine, USRPRP.f. You need to copy the Fortran subroutine USRPRP.F from the Aspen Polymers Plus application folder to your working directory. You then need to compile the subroutine before running this example. Alternately, you can copy the files USERFORT.DLL and USERFORT.DLOPT from the Aspen Polymers Plus application folder (app) to your working directory. Then, from the Aspen Plus menu bar, chose Run | Settings | Engine Files and enter USERFORT.DLOPT in the Linker Options box before running the simulation. Follow these instructions to: •

Run the simulation

•

Examine the results



.



.



2


3

Click

and



Input Summary The input language summary for this example is shown here: TITLE 'An example illustrating end-use property calculations' IN-UNITS MET DEF-STREAMS CONVEN ALL DESCRIPTION "The objective of this example is to demonstrate how to use Aspen Polymers Plus to predict important end-use properties including melt-index, intrinsic viscosity, and zero-shear viscosity for high-density polyethylene and other polyolefins using user-defined PROP-SETS. This example requires a user Fortran subroutine USRPRP.F.


89

Please copy USRPRP.F from the example directory and compile it in your local directory." DATABANKS POLYMER

/ SEGMENT


/ PURE11

/ SEGMENT

/ NOASPENPCD

/ PURE11

COMPONENTS HDPE PE / C2H4-R C2H4-R FLOWSHEET BLOCK B1 IN=1 OUT=2 PROPERTIES POLYFH POLYMERS SEGMENTS C2H4-R REPEAT POLYMERS HDPE ATTRIBUTES HDPE SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM SMOM

&

USER-PROPERT IV SUBROUTINE=USRPRP USER-PROPERT MI-K SUBROUTINE=USRPRP USER-PROPERT MI-S SUBROUTINE=USRPRP USER-PROPERT ZVIS SUBROUTINE=USRPRP PROP-SET IV IV SUBSTREAM=MIXED PROP-SET MI-K MI-K SUBSTREAM=MIXED PROP-SET MI-S MI-S SUBSTREAM=MIXED PROP-SET ZVIS ZVIS SUBSTREAM=MIXED STREAM 1 SUBSTREAM MASS-FLOW COMP-ATTR COMP-ATTR COMP-ATTR

MIXED TEMP=420. PRES=1. HDPE 1000. HDPE SFRAC ( 1. ) HDPE DPN ( 1000. ) HDPE PDI ( 3.61 )

BLOCK B1 HEATER PARAM TEMP=420. PRES=1. EO-CONV-OPTI SENSITIVITY END-USE DEFINE IV STREAM-PROP STREAM=2 PROPERTY=IV DEFINE MIK STREAM-PROP STREAM=2 PROPERTY=MI-K DEFINE MIS STREAM-PROP STREAM=2 PROPERTY=MI-S DEFINE ZVIS STREAM-PROP STREAM=2 PROPERTY=ZVIS TABULATE 1 "IV" COL-LABEL="IV" TABULATE 2 "MI-K" COL-LABEL="MI-K"

90


TABULATE 3 "MI-S" COL-LABEL="MI-S" TABULATE 4 "ZVIS" COL-LABEL="ZVIS" VARY BLOCK-VAR BLOCK=B1 VARIABLE=TEMP SENTENCE=PARAM RANGE LOWER="400" UPPER="500" INCR="10" STREAM-REPOR NOMOLEFLOW MASSFLOW

References Karol, F. J., Brown, G. L., & Davison, J. M. (1973). Chromocene-Based Catalysts for Ethylene Polymerization: Kinetic Parameters. J. Parameters. J. of Polymer Science: Polymer Chemistry Edition, Edition , 11, 11, pp. 413-424. Sinclair, K. B. (1983). Characteristics of Linear LPPE and Description of UCC Gas Phase Process. Process Economics Report . Menlo Park, CA: SRI International.


91

Section B - User Models

Aspen Polymers Plus currently supports the following user models: User Model

Description

Polymer fractionation algorithm

Polymer fractionation algorithm that performs isothermal flash calculations for vapor-liquid equilibria and liquid-liquid equilibria.

Aspen Polymers Plus - Predici Interface

Lets you link a Predici block to an Aspen Plus flowsheet through a graphical user interface.

There are two applications, one for general fl owsheeting (PolFrac1) and one that lets you directly enter MWD for phase analysis (PolFrac2).

To use a model, you select the model from the Polymer User Model Library and move it to the process flowsheet window. This is the same process used to place built-in blocks in a flowsheet. Note: Since these are used as system models, you cannot modify the calculation and variable configuration routines.

Installing Polymer User Model Library To install the Polymer User Model Library: Library: 1

From the menubar, click Library, Library, then References. References. A Library References dialog box appears.

2

Select Polymer User Model Library. Library.

3

Click OK. OK.

4

From the menubar, click Library, Library, then Palette Categories. Categories. A Palette Categories dialog box appears.

5

92

Click Polymer User Model Library and use the up arrow to move the Polymer User Model Library to the beginning of the Available Categories list.


6

Click OK. OK. Polymer User Model Library appears as the first tab in the Model Library.

The user models available on the Polymer User Model Library are: are: Model

Function

User Routines

Example

PolFrac1

Polymer fractionation algorithm with MWD from upstream reactors

UPFRAC.F

PolyfracMWD.bkp

PolFrac2

PREDICI


Polymer fractionation algorithm with user entered MWD Aspen Polymers Plus– Predici interface

VARFRAC1.F

UPFRAC.F VARFRAC2.F

UPREDI.F VARPREDI.F

PolyFracUserMWD.bk p

Available upon request

93

B1 Polymer Fractionation Algorithm

The polymer fractionation algorithm (PolyFrac) is a polymer flash algorithm based on PolyMix, which was originally developed by the research group of Professor Wolfgang Arlt at the Technology University of Berlin (Behme et al., 2003). PolyFrac performs phase equilibrium calculations for streams containing solvents and polymers. Most importantly, PolyFrac allows a polymer component to possess a molecular weight distribution (MWD), that is, the polydispersity. The topics covered include: •

Installing the Polymer Fractionation Examples

•

Developing a Proprietary Model

•

Example Polymer Fractionation Model - PolFrac1

•

Example Polymer Fractionation Model - PolFrac2

PolyFrac is implemented as a User2 model in Aspen Polymers Plus and performs isothermal flash calculations for vapor-liquid equilibria and liquidliquid equilibria using a pseudo-component approach. The algorithm is able to: •

Decompose feed polymer molecular weight distribution curves into a set of pseudo-components

•

Perform efficient flash calculations based on these pseudo-components

•

Reconstruct the polymer molecular weight distribution curves from pseudo-components for polymers in different phases

There are some restrictions for the model, namely the: •

System can only handle one polymer

•

Maximum limit of components is 50 (not including segments)

•

Maximum MWD points are 1000

The computation time is practically independent of the number of pseudocomponents used to mimic the molecular weight distribution. The model currently supports both the SAFT and PC-SAFT equations-of-state and provides two types of applications in Aspen Polymers Plus, PolFrac1 and PolFrac2. PolFrac1 is for general flowsheeting. PolFrac2 provides an interface that lets you directly enter MWD M WD for phase analysis.

94


Installing the Polymer Fractionation Examples The following files support the polymer fractionation user models: File Name

File Type

polyfracMWD.bkp polyfracMWD.bkp

Template backup file using MWD generated by upstream reactors

PolyfracUserMWD.bkp PolyfracUserMWD.bkp

Template backup file using user-entered MWD

Polymer User Model Library.apm Polymer User Model Library/Model Library/Model Library file PolyUserModelLib.dll PolyUserModelLib.dll

Polymer User Model Library/User DLL file

Polfrac2.ocx

Polymer User Model Library/Customized GUI

Creating a Working Directory To install the model: 1

Create a clean user working directory, such as: c:\polyfrac

2

Find the folder: Program Files\Aspentech\Aspen Plus 2004.1\GUI\xmp\Aspen Polymers Plus

3

From this folder, copy the two backup files listed in the table above to the working directory you created in step 1.

Developing a Proprietary Model In this example, a template file is created for the polymer fractionation model. You can open the template file to do a test run and replace the existing flowsheet, component, and streams with your own.

Opening the Model To start the model: 1

Go to your working directory, for example c:\polyfrac.

2

Double-click the polyfracMWD.bkp (or polyfracUSerMWD.bkp) file. The Aspen Plus main window is now active.

Specifying Pseudo-Componenets To change the number of pseudo-components: 1

From the Data Browser, double-click the Components folder, then the Polymers sub-folder.

2

Click the Distributions form.


95

3

On the Selection sheet, enter the appropriate No. points you need for your plot.

Running the Example To run the example: 1

To open the control panel, click

2

To start the run, click

.

.

Example Polymer Fractionation Model - PolFrac1 This example is a modification of the Polystyrene Bulk Polymerization by Thermal Initiation application example provided in Section C. In this example, the downstream Flash2 blocks are replaced with User2 polymer fractionation blocks. The example contains four user variables: •

Temperature (K)

•

Pressure (Pa)

•

Equation of state flag, where

•

o

PC-SAFT=1

o

SAFT=0

Diagnostics flag, where o

1=print diagnostics

o

0=do not print diagnostics

The number of pseudo-components is the same as the points of molecular distribution. The flowsheet for this example is shown here:

The results of the separation with MWD are plotted here:

96


Input Summary The input language summary for this example is shown here: TITLE

& 'Bulk Polymerization of Styrene by Thermal & Chemical Initiation'

IN-UNITS SI DEF-STREAMS CONVEN ALL SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=2000.0 DESCRIPTION " Styrene polymerization in two CSTR's followed by a plug flow reactor” DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS PS PS-1 / STY C8H8 / TBP C8H8 / CINI C8H8 / STY-SEG C8H8-R / EB C8H10-4 / DDM C12H26S / H2O H2O FLOWSHEET BLOCK CSTR-1 IN=FEED OUT=R1-P BLOCK CSTR-2 IN=R1-P OUT=R2-P BLOCK PLUG IN=R2-P OUT=R3-P BLOCK POLFRAC1 IN=R3-P OUT=R3-OLI REC-STY BLOCK POLFRAC2 IN=1 OUT=POLYMER WAX


97

BLOCK MIXER IN=STRIP-AG R3-OLI OUT=1 PROPERTIES POLYPCSF PROPERTIES POLYPCSF / POLYNRTL / POLYSAFT PROP-DATA DATA1 IN-UNITS SI PROP-LIST MW / TB PVAL TBP 216.320 / 2000.0 PVAL DDM 330.0 / 2000.0 PROP-DATA PCSAFT IN-UNITS SI PROP-LIST PCSFTM / PCSFTU / PCSFTV PVAL STY 3.0 / 285 / 3.75 PVAL TBP 3.0 / 285 / 3.75 PVAL CINI 3.0 / 285 / 3.75 PVAL EB 3.0 / 285 / 3.75 PVAL DDM 3.0 / 285 / 3.75 PVAL H2O 3.0 / 285 / 3.75 PROP-LIST PCSFTU / PCSFTV / PCSFTR PVAL PS 267 / 4.1071 / 0.0190 PROP-DATA PURE-1 IN-UNITS SI PROP-LIST SAFTM / SAFTU / SAFTV PVAL STY 4.7 / 245 / .013 PVAL EB 4.719 / 248.79 / .01268 PVAL PS 1000 / 210 / .012 PVAL TBP 5 / 300 / .05 PVAL CINI 3 / 300 / .03 PVAL DDM 3 / 300 / .03 PVAL H2O 1 / 400 / .018 PROP-DATA PLXANT-1 IN-UNITS SI PROP-LIST PLXANT PVAL TBP -30.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL DDM -30.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PROP-DATA PCSKIJ-1 IN-UNITS SI PROP-LIST PCSKIJ BPVAL PS STY 0.05 POLYMERS SEGMENTS STY-SEG REPEAT POLYMERS PS ATTRIBUTES PS SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM & SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW LEFRAC & LPFRAC DISTRIBUTION PS CHAIN-SIZE NPOINTS=200 FUNCLOG=NO & UPPER=100000. STREAM FEED SUBSTREAM MIXED TEMP=298.150 PRES=101325.0 MASS-FLOW=1.94440 NPHASE=1 PHASE=L MASS-FRAC STY .980 / TBP .000250 / EB .019370 / DDM &

98

&


.00060 STREAM STRIP-AG SUBSTREAM MIXED TEMP=298.150 PRES=202650.0 MASS-FLOW=.040 NPHASE=1 PHASE=L MASS-FLOW H2O .040

&

BLOCK MIXER MIXER PARAM PRES=1. NPHASE=1 PHASE=L PROPERTIES POLYPCSF BLOCK-OPTION FREE-WATER=NO BLOCK CSTR-1 RCSTR PARAM VOL=20.0 TEMP=393.150 PRES=101325.0 NPHASE=1 PHASE=L MB-MAXIT=200 MB-TOL=.000010 REACTIONS RXN-IDS=R1 BLOCK CSTR-2 RCSTR PARAM VOL=20.0 TEMP=433.150 PRES=101325.0 NPHASE=1 PHASE=L MB-MAXIT=400 MB-TOL=.000010 REACTIONS RXN-IDS=R1 BLOCK PLUG RPLUG PARAM TYPE=T-SPEC LENGTH=80.0 DIAM=.40 PHASE=L & PRES=101325.0 NPOINT=100 HINIT=1.0000E-07 INT-TOL=.0010 CORR-METHOD=DIRECT T-SPEC 0.0 433.150 / 1.0 473.150 REACTIONS RXN-IDS=R1 BLOCK POLFRAC1 USER2 SUBROUTINE UPFRAC PARAM NINT=2 NREAL=2 NCHAR=2 INT VALUE-LIST=1 1 REAL VALUE-LIST=493.15 101325. CHAR & CHAR-LIST="INT: (0) SAFT (1) PCSAFT-----REAL: "INT: (1) PRINT DIAGNOSTICS----REAL: PRESSURE PROPERTIES POLYPCSF / POLYPCSF BLOCK POLFRAC2 USER2 SUBROUTINE UPFRAC PARAM NINT=2 NREAL=2 NCHAR=2 INT VALUE-LIST=1 1 REAL VALUE-LIST=493.15 70000. CHAR & CHAR-LIST="INT: (0) SAFT (1) PCSAFT-----REAL: "INT: (1) PRINT DIAGNOSTICS----REAL: PRESSURE PROPERTIES POLYPCSF / POLYPCSF

&

&

&

TEMPERATURE IN DEG K" & IN PASCAL"

TEMPERATURE IN DEG K" & IN PASCAL"

EO-CONV-OPTI CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC REACTIONS R1 FREE-RAD DESCRIPTION "Free-Radical Kinetic Scheme"


99

PARAM QSSA=YES SPECIES INITIATOR=TBP COINITIATOR=CINI MONOMER=STY & CHAINTAG=EB DDM POLYMER=PS MON-RSEG STY STY-SEG INIT-DEC TBP 1.6220E+11 1.1530E+08 0.0 EFFIC=.80 NRADS=2 INIT-SP STY CINI 438000.0 1.1480E+08 0.0 CHAIN-INI STY 1.0510E+07 2.9570E+07 0.0 PROPAGATION STY STY 1.0510E+07 2.9570E+07 0.0 CHAT-MON STY STY 3310000.0 5.3020E+07 0.0 CHAT-AGENT STY EB 1051.0 2.9590E+07 0.0 CHAT-AGENT STY DDM 1051.0 2.9590E+07 0.0 TERM-COMB STY STY 1.2550E+09 7017000.0 0.0 INIT-SP-EFF STY COEFFA=0.0 COEFFB=3.0 COEFFC=0.0

Stream Report The stream report for this example is shown here: 1 FEED POLYMER R1-P R2-P -----------------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/SEC PS STY TBP CINI STY-SEG EB DDM H2O COMPONENTS: KG/SEC PS STY TBP CINI STY-SEG EB DDM H2O COMPONENTS: MASS FRAC PS STY TBP CINI STY-SEG EB DDM H2O

100

1 MIXER POLFRAC2

FEED ---CSTR-1

POLYMER POLFRAC2 ----

R1-P CSTR-1 CSTR-2

R2-P CSTR-2 PLUG

LIQUID

LIQUID

LIQUID

LIQUID

LIQUID

1.5140-02 2.2965-04 0.0 0.0 0.0 4.9967-05 4.9795-07 2.2203-03

0.0 1.8292-02 2.2466-06 0.0 0.0 3.5467-04 3.5345-06 0.0

1.5140-02 1.7490-05 0.0 0.0 0.0 7.3202-06 7.2949-08 3.2528-04

4.3369-03 1.3956-02 1.3463-06 0.0 0.0 3.5466-04 3.5344-06 0.0

1.1490-02 6.8065-03 6.9214-08 0.0 0.0 3.5463-04 3.5340-06 0.0

1.5768 2.3918-02 0.0 0.0 0.0 5.3049-03 1.6432-04 4.0000-02

0.0 1.9051 4.8599-04 0.0 0.0 3.7655-02 1.1664-03 0.0

1.5768 1.8217-03 0.0 0.0 0.0 7.7717-04 2.4073-05 5.8600-03

0.4517 1.4536 2.9123-04 0.0 0.0 3.7654-02 1.1663-03 0.0

1.1967 0.7089 1.4972-05 0.0 0.0 3.7650-02 1.1662-03 0.0

0.9579 1.4529-02 0.0 0.0 0.0 3.2225-03 9.9819-05 2.4298-02

0.0 0.9798 2.4995-04 0.0 0.0 1.9366-02 5.9987-04 0.0

0.9946 1.1491-03 0.0 0.0 0.0 4.9023-04 1.5185-05 3.6964-03

0.2323 0.7476 1.4978-04 0.0 0.0 1.9365-02 5.9985-04 0.0

0.6154 0.3646 7.7002-06 0.0 0.0 1.9363-02 5.9979-04 0.0


TOTAL FLOW: KMOL/SEC 1.7640-02 1.8652-02 1.5490-02 1.8653-02 1.8654-02 KG/SEC 1.6462 1.9444 1.5853 1.9444 1.9444 CUM/SEC 1.9860-03 2.1933-03 1.6607-03 2.3281-03 2.1922-03 STATE VARIABLES: TEMP K 495.3221 298.1500 493.1500 393.1500 433.1500 PRES N/SQM 1.0133+05 1.0133+05 7.0000+04 1.0133+05 1.0133+05 VFRAC 0.0 0.0 0.0 0.0 0.0 LFRAC 1.0000 1.0000 1.0000 1.0000 1.0000 SFRAC 0.0 0.0 0.0 0.0 0.0 ENTHALPY: J/KMOL 3.1753+07 1.0443+08 6.5992+07 1.0682+08 8.7482+07 J/KG 3.4025+05 1.0017+06 6.4480+05 1.0248+06 8.3930+05 WATT 5.6012+05 1.9478+06 1.0222+06 1.9925+06 1.6319+06 ENTROPY: J/KMOL-K -2.9690+05 -3.2838+05 -3.2725+05 -2.9332+05 -3.1215+05 J/KG-K -3181.4641 -3150.0706 -3197.5076 -2813.8475 -2994.7575 DENSITY: KMOL/CUM 8.8824 8.5039 9.3271 8.0119 8.5094 KG/CUM 828.9191 886.5019 954.5771 835.1701 886.9594 AVG MW 93.3218 104.2462 102.3447 104.2407 104.2330 COMPONENT ATTRIBUTES: PS SFRAC STY-SEG 1.0000 MISSING 1.0000 1.0000 1.0000 SFLOW STY-SEG 1.5140-02 MISSING 1.5140-02 4.3351-03 1.1485-02 DPN DPN 1201.5028 MISSING 1201.8758 1881.1753 1337.9002 DPW DPW 2310.6280 MISSING 2310.6296 3297.0214 2519.9759 PDI PDI 1.9231 MISSING 1.9225 1.7526 1.8835 MWN MWN 1.2514+05 MISSING 1.2518+05 1.9593+05 1.3934+05 MWW MWW 2.4066+05 MISSING 2.4066+05 3.4339+05 2.6246+05 ZMOM ZMOM 1.2601-05 MISSING 1.2597-05 2.3044-06 8.5844-06 FMOM FMOM 1.5140-02 MISSING 1.5140-02 4.3351-03 1.1485-02 SMOM SMOM 34.9824 MISSING 34.9824 14.2928 28.9421 LDPN LDPN 566.5407 MISSING 566.5407 1220.3105 778.8855 LZMOM LZMOM 8.0891-11 MISSING 8.0891-11 6.7910-11 8.8275-11 LFMOM LFMOM 4.5828-08 MISSING 4.5828-08 8.2871-08 6.8756-08 LSFLOW STY-SEG 4.5828-08 MISSING 4.5828-08 8.2871-08 6.8756-08 LSFRAC STY-SEG 1.0000 MISSING 1.0000 1.0000 1.0000 LEFLOW STY-SEG 8.0891-11 MISSING 8.0891-11 6.7910-11 8.8275-11 LEFRAC STY-SEG 1.0000 MISSING 1.0000 1.0000 1.0000 LPFRAC


101

LPFRAC

6.4196-06

MISSING

6.4216-06

2.9469-05

1.0283-05

R3-OLI R3-P REC-STY STRIP-AG WAX -------------------------------STREAM ID FROM : TO :

R3-OLI POLFRAC1 MIXER

R3-P PLUG POLFRAC1

REC-STY POLFRAC1 ----

SUBSTREAM: MIXED PHASE: LIQUID LIQUID VAPOR COMPONENTS: KMOL/SEC PS 1.5140-02 1.5140-02 2.9089-08 STY 2.2965-04 3.1565-03 2.9269-03 TBP 0.0 0.0 0.0 CINI 0.0 0.0 0.0 STY-SEG 0.0 0.0 0.0 EB 4.9967-05 3.5460-04 3.0463-04 DDM 4.9795-07 3.5337-06 3.0358-06 H2O 0.0 0.0 0.0 COMPONENTS: KG/SEC PS 1.5768 1.5768 3.0297-06 STY 2.3918-02 0.3288 0.3048 TBP 0.0 0.0 0.0 CINI 0.0 0.0 0.0 STY-SEG 0.0 0.0 0.0 EB 5.3049-03 3.7647-02 3.2342-02 DDM 1.6432-04 1.1661-03 1.0018-03 H2O 0.0 0.0 0.0 COMPONENTS: MASS FRAC PS 0.9817 0.8110 8.9588-06 STY 1.4891-02 0.1691 0.9014 TBP 0.0 0.0 0.0 CINI 0.0 0.0 0.0 STY-SEG 0.0 0.0 0.0 EB 3.3027-03 1.9362-02 9.5634-02 DDM 1.0230-04 5.9974-04 2.9623-03 H2O 0.0 0.0 0.0 TOTAL FLOW: KMOL/SEC 1.5420-02 1.8654-02 3.2345-03 KG/SEC 1.6062 1.9444 0.3382 CUM/SEC 1.6518-03 2.1173-03 0.1286 STATE VARIABLES: TEMP K 493.1500 473.1500 493.1500 PRES N/SQM 1.0133+05 1.0133+05 1.0133+05 VFRAC 0.0 0.0 1.0000 LFRAC 1.0000 1.0000 0.0 SFRAC 0.0 0.0 0.0 ENTHALPY: J/KMOL 7.4075+07 8.1124+07 1.6671+08 J/KG 7.1113+05 7.7830+05 1.5945+06 WATT 1.1422+06 1.5133+06 5.3922+05 ENTROPY: J/KMOL-K -3.3072+05 -3.1704+05 -1.5392+05 J/KG-K -3174.9331 -3041.6257 -1472.2088 DENSITY: KMOL/CUM 9.3352 8.8105 2.5158-02

102

STRIP-AG ---MIXER

WAX POLFRAC2 ----

LIQUID

VAPOR

0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.2203-03

1.0277-08 2.1216-04 0.0 0.0 0.0 4.2647-05 4.2500-07 1.8951-03

0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.0000-02

1.0703-06 2.2097-02 0.0 0.0 0.0 4.5277-03 1.4025-04 3.4140-02

0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0000

1.7573-05 0.3628 0.0 0.0 0.0 7.4340-02 2.3027-03 0.5605

2.2203-03 4.0000-02 2.2491-04

2.1503-03 6.0906-02 0.1244

298.1500 2.0265+05 0.0 1.0000 0.0

493.1500 7.0000+04 1.0000 0.0 0.0

-2.6217+08 -1.8858+08 -1.4553+07 -6.6580+06 -5.8211+05 -4.0551+05 -1.0863+05 -3.7124+04 -6029.9512 -1310.6748 9.8722

1.7283-02


KG/CUM AVG MW COMPONENT ATTRIBUTES: PS SFRAC STY-SEG SFLOW STY-SEG DPN DPN DPW DPW PDI PDI MWN MWN MWW MWW ZMOM ZMOM FMOM FMOM SMOM SMOM LDPN LDPN LZMOM LZMOM LFMOM LFMOM LSFLOW STY-SEG LSFRAC STY-SEG LEFLOW STY-SEG LEFRAC STY-SEG LPFRAC LPFRAC

972.3997 104.1653

918.3406 104.2326

2.6304 104.5533

177.8497 18.0153

0.4895 28.3243

1.0000

1.0000

1.0000

MISSING

1.0000

1.5140-02

1.5135-02

2.9089-08

MISSING

1.0277-08

1201.5028

1217.9263

2.0283

MISSING

2.6220

2310.6280

2339.0237

2.2639

MISSING

2.8393

1.9231

1.9205

1.1161

MISSING

1.0829

1.2514+05

1.2685+05

211.2511

MISSING

273.0855

2.4066+05

2.4361+05

235.7853

MISSING

295.7165

1.2601-05

1.2427-05

1.4342-08

MISSING

3.9194-09

1.5140-02

1.5135-02

2.9089-08

MISSING

1.0277-08

34.9824

35.4012

6.5855-08

MISSING

2.9178-08

566.5407

566.5407

566.5407

MISSING

566.5407

8.0891-11

8.0892-11

1.5542-16

MISSING

5.4907-17

4.5828-08

4.5828-08

8.8054-14

MISSING

3.1107-14

4.5828-08

4.5828-08

8.8054-14

MISSING

3.1107-14

1.0000

1.0000

1.0000

MISSING

1.0000

8.0891-11

8.0892-11

1.5542-16

MISSING

5.4907-17

1.0000

1.0000

1.0000

MISSING

1.0000

6.4196-06

6.5094-06

1.0837-08

MISSING

1.4009-08

Example Polymer Fractionation Model - PolFrac2 This example is an application of PolyFrac that lets you directly enter your own MWD data for phase analysis. This application provides a User2 block interface, PolFrac2, to enter MWD data:


103

You have to enter values for four user variables: •

Temperature (K)

•

Pressure (Pa)

•

Equation of state flag, where

•

o

PC-SAFT=1

o

SAFT=0

Diagnostics flag, where o

1=print diagnostics

o

0=do not print diagnostics

In the Number of points field, you can specify the number of pseudocomponents to represent the molecular weight distribution (MWD). Based on this number, both columns for molecular weight and feed mole fractions will expand to be the exact number of rows. You can then enter values for the molecular weight and mole fraction of each pseudo-component. In this example, the feed stream consists of a polydisperse polyethylene and a number of hydrocarbon solvents (ethylene, propane, n-hexane, n-heptane, and cyclohexane) at temperature 473.15 K and 10000000 Pa. The polydisperse polyethylene is characterized by 20 pseudo-components, ranging from 10 to 50000 in molecular weight. The flowsheet for this example is shown here:

104


The components defined for this example are:

The molecular weight distribution (MWD) of the pseudo-components in the feed stream is characterized by the mole fractions. It performs a TP flash calculation using the PC-SAFT equation of state for thermodynamic properties. The feed stream flashes into a solvent-rich phase that contains the PE lights and a polymer-rich phase that contains the PE heavies as shown in the Results field of PolFrac2:


105

Input Summary The input language summary for this example is shown here: IN-UNITS MET DEF-STREAMS CONVEN ALL DESCRIPTION "This example is an application of PolyFrac that allows users directly enter their own MWD data for phase analysis" DATABANKS POLYMER

/ SEGMENT


/ PURE12

/ SEGMENT

/ NOASPENPCD

/ PURE12

COMPONENTS C2H4-R C2H4-R / PE PE / ETHYLENE C2H4 / PROPANE C3H8 / HEXANE C6H14-1 / HEPTANE C7H16-1 / CYCLOHE C6H12-1 FLOWSHEET BLOCK POLFRAC2 IN=FEED OUT=PHASE2 PHASE1 PROPERTIES POLYPCSF PROPERTIES POLYSAFT PROP-DATA PCSAFT IN-UNITS MET PROP-LIST PCSFTM / PCSFTU / PCSFTV PVAL ETHYLENE 1.5930 / 176.47 / 3.4450

106


PVAL PROPANE 2.0020 / 208.11 / 3.6184 PVAL HEXANE 3.0576 / 236.77 / 3.7983 PVAL HEPTANE 3.4831 / 238.40 / 3.8049 PVAL CYCLOHE 2.5303 / 278.11 / 3.8499 PROP-LIST PCSFTU / PCSFTV / PCSFTR PVAL C2H4-R 252 / 4.0217 / 0.0263 PROP-DATA PCSKIJ-1 IN-UNITS MET PROP-LIST PCSKIJ BPVAL HDPE ETHYLENE 0.0436 POLYMERS SEGMENTS C2H4-R REPEAT POLYMERS HDPE ATTRIBUTES HDPE SFRAC SFLOW DPN MWN ZMOM FMOM STREAM FEED SUBSTREAM MIXED TEMP=473.15 PRES=100. MOLE-FLOW HDPE 1. / ETHYLENE 1022. / PROPANE 100. / HEXANE 10. / HEPTANE 10. / CYCLOHE 20. COMP-ATTR HDPE SFRAC ( 1. ) COMP-ATTR HDPE DPN ( 1000. )

&

BLOCK POLFRAC2 USER2 IN-UNITS ENG SUBROUTINE UPFRAC PARAM NINT=3 NREAL=82 INT VALUE-LIST= & 1 & ;EOSFLAG 1 & ;DIAGFLAG 20 ;NPOINT REAL VALUE-LIST= & 473.15 & ;TEMP 10000000 & ;PRES 8.0813 & ;XVEC(1) 274.765 & ;XVEC(2) 541.4487 & ;XVEC(3) 808.1324 & ;XVEC(4) 3850.5134 & ;XVEC(5) 6892.8945 & ;XVEC(6) 9935.2754 & ;XVEC(7) 12977.6563 & ;XVEC(8) 16020.0361 & ;XVEC(9) 19062.416 & ;XVEC(10) 22104.7969 & ;XVEC(11) 25147.1777 & ;XVEC(12) 28189.5586 & ;XVEC(13) 31231.9414 & ;XVEC(14) 34274.3242 & ;XVEC(15) 37316.7031 & ;XVEC(16) 40359.0859 & ;XVEC(17) 43401.4688 & ;XVEC(18) 46443.8477 & ;XVEC(19) 49486.2305 & ;XVEC(20) 3.12E-006 & ;YVEC(1) 0.00341106 & ;YVEC(2)


107

0.00914166 & ;YVEC(3) 0.01394328 & ;YVEC(4) 0.30768341 & ;YVEC(5) 0.29445428 & ;YVEC(6) 0.18293452 & ;YVEC(7) 0.09792537 & ;YVEC(8) 0.04856635 & ;YVEC(9) 0.02299082 & ;YVEC(10) 0.01054726 & ;YVEC(11) 0.00473049 & ;YVEC(12) 0.00208576 & ;YVEC(13) 0.00090746 & ;YVEC(14) 0.00039061 & ;YVEC(15) 0.00016666 & ;YVEC(16) 7.059E-005 & ;YVEC(17) 2.971E-005 & ;YVEC(18) 1.244E-005 & ;YVEC(19) 5.18E-006 & ;YVEC(20) USER-MODELS CONFIG=VARFRAC2 EO-CONV-OPTI STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC PROPERTY-REP NOPARAM-PLUS

Stream Report The stream report for this example is given here: FEED PHASE1 PHASE2 -----------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR C2H4-R PE ETHYLENE PROPANE HEXANE HEPTANE CYCLOHE COMPONENTS: KG/HR C2H4-R PE ETHYLENE PROPANE HEXANE HEPTANE CYCLOHE

108

FEED ---POLFRAC2

PHASE1 POLFRAC2 ----

PHASE2 POLFRAC2 ----

MIXED

MISSING

LIQUID

0.0 1.0000 1022.0000 100.0000 10.0000 10.0000 20.0000

0.0 0.0 0.0 0.0 0.0 0.0 0.0

0.0 1.0000 1022.0000 100.0000 10.0000 10.0000 20.0000

0.0 28.0538 2.8671+04 4409.6520 861.7716 1002.0404 1683.2256

0.0 0.0 0.0 0.0 0.0 0.0 0.0

0.0 28.0538 2.8671+04 4409.6520 861.7716 1002.0404 1683.2256


COMPONENTS: MASS FRAC C2H4-R PE ETHYLENE PROPANE HEXANE HEPTANE CYCLOHE TOTAL FLOW: KMOL/HR KG/HR L/MIN STATE VARIABLES: TEMP K PRES ATM VFRAC LFRAC SFRAC ENTHALPY: CAL/MOL CAL/GM CAL/SEC ENTROPY: CAL/MOL-K CAL/GM-K DENSITY: MOL/CC GM/CC AVG MW COMPONENT ATTRIBUTES: PE SFRAC C2H4-R SFLOW C2H4-R DPN DPN MWN MWN ZMOM ZMOM FMOM FMOM

0.0 7.6533-04 0.7822 0.1203 2.3510-02 2.7337-02 4.5920-02 1163.0000 3.6656+04 6540.9120

MISSING MISSING MISSING MISSING MISSING MISSING MISSING 0.0 0.0 0.0

0.0 7.6533-04 0.7822 0.1203 2.3510-02 2.7337-02 4.5920-02 1163.0000 3.6656+04 858.6795

473.1500 98.6923 0.9991 9.2453-04 0.0

MISSING 98.6923 MISSING MISSING MISSING

473.1500 98.6923 0.0 1.0000 0.0

9485.3620 300.9486 3.0643+06

MISSING MISSING MISSING

9156.7392 290.5221 2.9581+06

-24.1369 -0.7658

MISSING MISSING

-24.6602 -0.7824

2.9634-03 9.3401-02 31.5182


2.2573-02 0.7115 31.5182

1.0000

MISSING

1.0000

1.0000

MISSING

1.0000

1000.0000

MISSING

1000.0000

2.8054+04

MISSING

2.8054+04

1.0000-03

MISSING

1.0000-03

1.0000

MISSING

1.0000

References Behme, S., Sadowski, G., Song, Y., & Chen, C.-C. (2003). Multicomponent Flash Algorithm for Mixtures Containing Polydisperse Polymers. AIChE J., J., 49, 49, pp. 258-268.


109

B2 Aspen Polymers PlusPredici Interface

Modeling of complex polymerization processes requires a detailed description of the thermophysical properties, chemical kinetics, unit operation models, and flowsheeting capabilities of a simulator. Aspen Polymers Plus provides these features, while Predici provides useful descriptions of kinetics and polymer molecular weight distribution. The Aspen Polymers Plus-Predici interface lets you combine the strengths of both packages. The Aspen Polymers Plus-Predici interface lets you enter the Predici model name, working directory, connections between Aspen stream and Predici reactors, and mapping between Aspen component name and Predici alias name. It also supports data transfer between Aspen and Predici through COM technology. This example demonstrates how to integrate a Predici model in Aspen Plus as a flowsheet reactor block. The topics covered include: •

Developing a Proprietary Model

•

Example Predici Four CSTR Model

Developing a Proprietary Model The Aspen Polymers Plus-Predici interface is included in the Polymer User Model Library as the PREDICI model.

Opening the Model To start the Aspen Polymers Plus-Predici model: 1

From the menubar, click Library, Library, then References. References. A Library References dialog box appears.

110

2

Select Polymer User Model Library. Library.

3

Click OK. OK.

B2 Aspen Polymers Plus-Predici Interface

4

Click the PREDICI model and move the model to the process flowsheet window.

5

Rename block B1 to PREDICI. PREDICI.

Linking the Model with Predici To link the Predici model file to Aspen Plus: 1

In Aspen Plus, to open the Data Browser, click

2

In the Menu Tree, double-click the Blocks folder, and then click the PREDICI sub-folder.

3

On the Connection sheet, in Predici working path, path, enter the path to your Predici working folder and, in Model name (*.rsy), (*.rsy), enter the name of your Predici model file.

4

In Integration time (sec), (sec), enter the integration time for the Predici calculation.

5

In No. of connections, connections , enter the total number of the stream connections between Aspen and Predici.

.

If the Predici block has two input streams and one output stream, the total number of connections is 3. The right arrow (=>) indicates that the stream is from Aspen to the Predici block, and the left arrow (<=) indicates the stream is from the Predici block to Aspen.

Mapping the Components The naming convention for Aspen components is different than that used in Predici. In order to share the stream data between the two products, a Component Mapping sheet is provided. This sheet links the Aspen components to the Predici alias names.


111

Specifying Predici Alias Names Predici species are based on either a direct name or an alias name. In the following example, the monomer in reactor R2 is referred to directly as M_2 or indirectly by the alias Monomer.

Aspen uses only one set of component names. Therefore, if you want to use a Predici model in Aspen, you need to have alias names defined in Predici.

Creating an Alias Text File To make a selection list of Predici alias names in Aspen, a text file needs to be manually created. To create this file: 1

Open a text editor (for example, Notepad).

2

Starting at row one, type the counter for the length of the list (N).

3

N = total number of alias names names + 1

4

Starting at row two, type the alias names, one per line. For this example, there are 3 element species and 1 polymer species.

5

At the end of the list, type a dummy alias name, none. none. The dummy alias is used when the Aspen components do not have a corresponding Predici alias.

6

112

Save the file as a *.txt file in your working directory. In this example, the file name is AliasName.txt.


Note: This process will be automated in future releases of Aspen Polymers Plus.

Mapping Names Between Aspen and Predici To map the Aspen components to the Predici alias: 1

In the Menu Tree, go to the PREDICI sub-folder.

2

On the Component Mapping sheet, click the Browse button. A Select Predici Alias File dialog box appears.

3

Locate your working directory, and click the alias name file.

4

The *.txt file appears in the Predici alias file location field.

Note: The alias file is required to enable the Component Mapping section of the form and to populate the selection list in the Predici Component Alias column. 5

Click the down-arrow in the Predici Component Alias column, and from the selection list, click the Predici alias name that corresponds to the Aspen component.

Note: If the Aspen component is a segment, map the corresponding monomer to the segment. If an Aspen component component is not used in Predici, map map the dummy alias, none, none, to that component.

Specifying Stream Flash To set stream flash options: 1

In the Menu Tree, click the PREDICI sub-folder.

2

On the Stream Flash sheet, in the Stream field click the product stream, and in the Flash type field, select the flash type.

Note: Defining stream flash completes the rest of the polymer attributes based on moments and polymer composition.


113

Running the Example To start the run: 1

To open the control panel, click

2

To start the run, click

.

.

Note: The Predici application window appears when the Predici block is executed in the Aspen calculations. The Predici window closes automatically after the calculation is complete.

Example Predici Four CSTR Model This example describes how to integrate a Predici CSTR polymerization model with Aspen Polymers Plus. The Predici reactors are connected with the Aspen reactors as shown in the following figure. The Aspen reactors are shown in

114


Section I (Aspen1 feeds to R1, Aspen2 and Aspen3 mixed and feed to R2). The Predici model, which has four CSTR in cascade, is shown in Section II.

Section I

Section II

The Aspen flowsheet corresponding to the above figure is shown here:

The four CSTR are treated as one Predici block with two feed streams. For the Connections, Component Mapping, and Flash Options entries, see Developing 110. a Proprietary Model on page 110.

Results The chain length distribution for this example is shown here:


115

Input Summary The input language summary for this example is shown here: TITLE 'Demo for Aspen Polymers Plus – Predici Interface' IN-UNITS MET DEF-STREAMS CONVEN ALL DESCRIPTION " Polymers Simulation with Metric Units : K, atm, kg/hr, kmol/hr, cal/sec, l/min. Property Method: None Flow basis for input: Mass Stream report composition: Mass flow " DATABANKS POLYMER / SEGMENT / PURE11 / INORGANIC / NOASPENPCD PROP-SOURCES POLYMER / SEGMENT SOLIDS / INORGANIC

/ AQUEOUS

/ PURE11

/ SOLIDS

/ AQUEOUS

/

&

&

COMPONENTS MMA C5H8O2-D3 / INITIAT C5H8O2-D3 / SOLVENT C10H16O4-D1 / PMMA PMMA / MMA-R C5H8O2-R-1 FLOWSHEET BLOCK MIXER IN=ASPEN2 ASPEN3 OUT=ASPEN2-3 BLOCK PREDICI IN=ASPEN1 ASPEN2-3 OUT=PROD

116


PROPERTIES POLYNRTL PROP-DATA MW IN-UNITS MET PROP-LIST MW PVAL MMA 100.000 PVAL INITIAT 100.000 PVAL SOLVENT 200.000 POLYMERS SEGMENTS MMA-R REPEAT POLYMERS PMMA ATTRIBUTES PMMA SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM & FMOM SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW & LEFRAC LPFRAC DISTRIBUTION PMMA FUNCLOG=YES UPPER=1000. STREAM ASPEN1 SUBSTREAM MIXED TEMP=20. PRES=1. MASS-FLOW MMA 0.00999 / INITIAT 1E-005 STREAM ASPEN2 SUBSTREAM MIXED TEMP=20. PRES=1. MASS-FLOW MMA 0.0199 / INITIAT 0.0001 STREAM ASPEN3 SUBSTREAM MIXED TEMP=20. PRES=1. MASS-FLOW MMA 0.0099 / INITIAT 0.0001 BLOCK MIXER MIXER BLOCK PREDICI USER2 SUBROUTINE UPREDI PARAM NCHAR=9 INT VALUE-LIST= & 3 ;NCONNECT REAL VALUE-LIST= & 2000 ;PTIME CHAR CHAR-LIST= & "MONOMER" & ;PALIAS(1) "INITIATOR" & ;PALIAS(2) "SOLVENT" & ;PALIAS(3) "DEAD" & ;PALIAS(4) "MONOMER" & ;PALIAS(5) "R1" & ;PREACTOR(1) "R2" & ;PREACTOR(2) "R4" & ;PREACTOR(3) "D:\PREDICI\R12DEV\4CSTR\TESTFILE.TXT" FLASH-SPECS PROD TP USER-MODELS CONFIG=VARPCSTR


;PALIADIR

117

Stream Report The stream report for this example is shown here: ASPEN1

ASPEN2-3

PREDICI

PREDICI

PROD

MIXER

PREDICI

LIQUID

LIQUID

LIQUID

MMA

0.35964

1.0728

0.2856496

INITIAT

3.60E-04

7.20E-03

2.50E-10

SOLVENT

0

0

1.69E-05

PMMA

0

0

1.140579

MMA

35.964

107.28

28.56496

INITIAT

0.036

0.72

2.50E-08

SOLVENT

0

0

3.38E-03

PMMA

0

0

114.1917

MMA

0.999

0.9933333

0.2000908

INITIAT

1.00E-03

6.67E-03

1.75E-10

SOLVENT

0

0

2.36E-05

PMMA

0

0

0.7998856

Substream: MIXED Mole Flow

Mass Flow

kmol/hr

kg/hr

Mass Frac

118

Total Flow

kmol/hr

0.36

1.08

1.426245

Total Flow

kg/hr

36

108

142.76

Total Flow

l/min

0.6388124

1.916439

2.173202

Temperature K

293.15

293.1509

273.15

Pressure

1

1

1

Vapor Frac

0

0

0

Liquid Frac

1

1

1

Solid Frac

0

0

0

atm

Enthalpy

cal/mol

-95549.52

-95549.52

-1.04E+05

Enthalpy

cal/gm

-955.4952

-955.4952

-1036.975

Enthalpy

cal/sec

-9554.952

-28664.86

-41121.83

Entropy

cal/mol-K cal/molK

-110.9926

-110.9286

-132.6169


Entropy

cal/gm-K

-1.109926

-1.109286

-1.32491

Density

mol/cc

9.39E-03

9.39E-03

0.0109381

Density

gm/cc

0.9392429

0.939242

1.094851

Average MW

100

100

100.095

Liq Vol 60F l/min

0.640416

1.921248

PMMA SFRAC MMA-R PMMA SFLOW

1 kmol/hr

MMA-R

1.110469

PMMA DPN DPN

75.33884

PMMA DPW DPW

146.9359

PMMA PDI PDI

1.950334

PMMA MWN MWN

7542.723

PMMA MWW MWW PMMA ZMOM

14710.83 kmol/hr

ZMOM PMMA FMOM

0.0147396 kmol/hr

FMOM PMMA SMOM

1.110469 kmol/hr

SMOM

163.1678

PMMA LDPN LDPN PMMA LZMOM

0 kmol/hr

LZMOM PMMA LFMOM

0 kmol/hr

LFMOM

0.0314478

PMMA LSFLOW kmol/hr MMA-R

0.0314478

PMMA LSFRAC MMA-R


1

119

120


C1 Polystyrene Bulk Polymerization by Thermal Initiation

The polystyrene bulk polymerization by thermal initiation model illustrates the use of Aspen Polymers Plus for modeling free-radical bulk polymerization of styrene with thermal and peroxide initiation. The part of the process modeled is the polymerization stage and subsequent devolatilization. This model is used to study the effect of feed flow rate on styrene conversion, polymer properties, and recycle flowrate.

About This Process Typically in free-radical polymerization, an initiator decomposes to form free radicals that initiate chain growth. Propagation reactions add successive monomer molecules to a growing polymer chain to increase its chain length. A growing polymer chain terminates by either chain transfer or termination reactions to form dead polymer chains. Styrene monomer, when heated to polymerization temperatures above 120 °C, can generate enough free-radicals to produce high conversion and high molecular weight polymer. Styrene reacts via a Diels-Alder-type mechanism to form dimers that react with an additional styrene molecule to produce freeradicals. The thermal initiation rate has been reported to be third-order in styrene concentration (Hui & Hamielec, 1972).

Process Definition Styrene is polymerized in a reactor train consisting of two CSTRs followed by a plug flow reactor. All of the reactors are considered liquid filled, and are therefore modeled without taking into account vapor-liquid equilibrium. Unreacted monomer is flashed in a devolatilizer to be modeled as an ideal flash unit.

The flowsheet consists of two RCSTR in series, one RPlug, a Heater, and two Flash2 blocks:

Process Conditions The first CSTR operates at 120 °C, 1 atm, and the second operates at 160°C, 1 atm. Both have a volume of 20 . The plug flow reactor operates at 1 atm, with a temperature range of 160-200 °C from the inlet to the outlet. The process conditions are: Components

Name

Databank

Description

Styrene

STY

PURE12

Monomer

Polystyrene

PS

POLYMER

Polymer component

STY-SEG

SEGMENT

Styrene segment

Di-tert-butyl peroxide

TBP

PURE12

Initiator (Mw=216.32) (Mw=216.32)

Coinitiator

CINI

PURE12

Coinitiator

Ethylbenzene

EB

PURE12

Chain transfer agent

Dodecyl mercaptan

DDM

PURE12

Chain transfer agent (Mw=330.0)

Water

H2O

PURE12

Stripping agent

Physical Properties

POLYNRTL property method

Feeds

122

Temperature (°C)

25

Pressure (atm)

1

Mass Flow (kg/hr)

7000


Mass fraction of styrene

.98

Mass fraction of polystyrene

0.0

Mass fraction of coinitiator

0.0

Mass fraction of ethylbenzene

0.019

Mass fraction of DDM

0.0007

Mass fraction of TBP

0.0003

Kinetics

FREE-RAD model

Operating Conditions

Block

Temp ( C)

Pres (atm)

Size

CSTR-1

120

1

20 m3

CSTR-2

160

1

20 m3

PLUG

160-200

1

80 m length by 0.40 m diam

DV-H1

220

1

FLASH-1

220

1

FLASH-2

220

1

Physical Property Models and Data The Polymer Non-Random Two Liquid activity coefficient model physical property method (POLYNRTL) is used. As no parameters are provided, the thermophysical properties (density, heat capacity, etc.) of styrene, ethylbenzene, dodecyl mercaptan, di-tert-butyl peroxide, and water are calculated using parameters from the Pure Component Databank. Note that the coinitiator is given the properties of styrene. However, as this component is used only as a dummy component for the thermal initiation reaction, results are not affected. The polymer thermophysical properties are calculated using the van Krevelen group contribution method.

Reactors / Kinetics The kinetics of bulk and solution polymerization of styrene have been studied extensively. It has been reported (Albright, 1985) that chain transfer to the monomer and the Diels-Alder dimers primarily controls the molecular weight of polystyrene. Furthermore, based on chemical evidence and kinetic modeling, it has been reported that termination of the growing chains occurs principally by combination over disproportionation. The reactions included from the built-in free-radical kinetics are: Description

Reaction

Initiator decomposition

I

Thermal initiation

→R

•

Chain initiation Propagation Chain transfer to monomer Chain transfer to EB

P n

+ EB → Dn + R •

Chain transfer to DDM

P n

+ DDM → Dn + R

•

Termination by combination

The unit for the rate constant for the thermal initiation reaction is while the unit for the rate constant for initiator decomposition reaction is 1/s. The units for the rate constants for the other reactions are . The induced initiation reaction is configured for thermal initiation by setting the power to be third-order t hird-order with respect to monomer. A coinitiator, which is required for the induced initiation reaction, is included in the list of components, but its power and feed rate are set to zero so that it will not influence the rate for the thermal initiation reaction.

Process Studies The model is used to study the effect of feed flow rate on styrene conversion, polymer properties, and recycle styrene flowrate. In order to determine the effect of feed flowrate on styrene conversion, polymer properties, and recycle flowrate, a sensitivity study is carried out with feed mass flow as the varied parameter.

Input Summary An input language summary for this example is shown here: ; Free radical bulk polymerization of styrene by thermal and chemical ; initiation ; QSSA case ; DYNAPLUS DPLUS RESULTS=ON TITLE

& 'Bulk Polymerization of Styrene by Thermal & Chemical Initiation'

IN-UNITS MET ENTHALPY-FLO='kcal/hr' PRESSURE=bar TEMPERATURE=C & DELTA-T=C MOLE-ENTHALP='kcal/kmol' MASS-ENTHALP='kcal/kg' HEAT=kcal PDROP=bar INVERSE-PRES='1/bar'

&

DEF-STREAMS CONVEN ALL SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=2000.0

124


DESCRIPTION "Styrene polymerization in two CSTR's followed by a plug flow reactor and two stage devolitization" DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS TBP C8H18O2 / CINI C8H8 / STY C8H8 / PS PS-1 / STY-SEG C8H8-R / EB C8H10-4 / DDM C12H26S / H2O H2O FLOWSHEET BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK

CSTR-1 IN=FEED OUT=R1-P CSTR-2 IN=R1-P OUT=R2-P PLUG IN=R2-P OUT=R3-P FLASH-1 IN=R3-PH2 OUT=REC-STY R3-OLI FLASH-2 IN=R3-OLI STRIP-AG OUT=VAPOR PRODUCT DV-H1 IN=R3-P OUT=R3-PH2

PROPERTIES POLYNRTL PROP-DATA MW IN-UNITS MET ENTHALPY-FLO='kcal/hr' PRESSURE=bar & TEMPERATURE=C DELTA-T=C MOLE-ENTHALP='kcal/kmol' MASS-ENTHALP='kcal/kg' HEAT=kcal PDROP=bar & INVERSE-PRES='1/bar' PROP-LIST MW PVAL TBP 216.320

&

POLYMERS SEGMENTS STY-SEG REPEAT POLYMERS PS ATTRIBUTES PS SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM & SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW LEFRAC & LPFRAC DISTRIBUTION PS

STREAM FEED SUBSTREAM MIXED TEMP=25.00000 PRES=1.013250 MASS-FLOW=7000. NPHASE=1 PHASE=L MASS-FRAC TBP 0.0003 / STY .980 / EB 0.019 / DDM & 0.0007 STREAM STRIP-AG SUBSTREAM MIXED TEMP=25.00000 PRES=2.026500 MASS-FLOW=144.0000 NPHASE=1 PHASE=L MASS-FLOW H2O 144.0000 BLOCK DV-H1 HEATER PARAM TEMP=220.0000 PRES=1.013250

&

&

BLOCK FLASH-1 FLASH2 PARAM TEMP=220.0000 PRES=1.013250 MAXIT=200 BLOCK FLASH-2 FLASH2 PARAM TEMP=220.0000 PRES=1.013250 MAXIT=200 BLOCK CSTR-1 RCSTR PARAM VOL=20. TEMP=120.0000 PRES=1.013250 NPHASE=1 PHASE=L MB-MAXIT=200 MB-TOL=.000010 REACTIONS RXN-IDS=R1

&

BLOCK CSTR-2 RCSTR PARAM VOL=20. TEMP=160.0000 PRES=1.013250 NPHASE=1 PHASE=L MB-MAXIT=400 MB-TOL=.000010 REACTIONS RXN-IDS=R1 BLOCK PLUG RPLUG PARAM TYPE=T-SPEC LENGTH=80.00000 DIAM=.4000000 PHASE=L PRES=1.013250 HINIT=1.0000E-07 INT-TOL=.0010 & CORR-METHOD=DIRECT T-SPEC 0.0 160.0000 / 1.0 200.0000 REACTIONS RXN-IDS=R1

&

&

EO-CONV-OPTI SENSITIVITY S1 IN-UNITS SI DEFINE R3MWN COMP-ATTR-VAR STREAM=R3-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWN ELEMENT=1 DEFINE R3MWW COMP-ATTR-VAR STREAM=R3-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWW ELEMENT=1 DEFINE R3PDI COMP-ATTR-VAR STREAM=R3-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=PDI ELEMENT=1 DEFINE R2MWN COMP-ATTR-VAR STREAM=R2-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWN ELEMENT=1 DEFINE R2MWW COMP-ATTR-VAR STREAM=R2-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWW ELEMENT=1 DEFINE R2PDI COMP-ATTR-VAR STREAM=R2-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=PDI ELEMENT=1 DEFINE R1MWN COMP-ATTR-VAR STREAM=R1-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWN ELEMENT=1 DEFINE R1MWW COMP-ATTR-VAR STREAM=R1-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=MWW ELEMENT=1 DEFINE R1PDI COMP-ATTR-VAR STREAM=R1-P SUBSTREAM=MIXED COMPONENT=PS ATTRIBUTE=PDI ELEMENT=1 DEFINE R3STY MASS-FRAC STREAM=R3-P SUBSTREAM=MIXED & COMPONENT=STY DEFINE R3PS MASS-FRAC STREAM=R3-P SUBSTREAM=MIXED & COMPONENT=PS DEFINE R2STY MASS-FRAC STREAM=R2-P SUBSTREAM=MIXED & COMPONENT=STY DEFINE R2PS MASS-FRAC STREAM=R2-P SUBSTREAM=MIXED & COMPONENT=PS DEFINE R1STY MASS-FRAC STREAM=R1-P SUBSTREAM=MIXED & COMPONENT=STY DEFINE R1PS MASS-FRAC STREAM=R1-P SUBSTREAM=MIXED &

126

& & & & & & & & &


F F F

COMPONENT=PS DEFINE RECY STREAM-VAR STREAM=REC-STY SUBSTREAM=MIXED VARIABLE=MASS-FLOW R3CONV = R3PS/(R3STY + R3PS) R2CONV = R2PS/(R2STY + R2PS) R1CONV = R1PS/(R1STY + R1PS) TABULATE 1 "R1CONV" COL-LABEL="R1CONV" TABULATE 2 "R2CONV" COL-LABEL="R2CONV" TABULATE 3 "R3CONV" COL-LABEL="R3CONV" TABULATE 4 "R1MWN" COL-LABEL="R1MWN" TABULATE 5 "R1MWW" COL-LABEL="R1MWW" TABULATE 6 "R2MWN" COL-LABEL="R2MWN" TABULATE 7 "R2MWW" COL-LABEL="R2MWW" TABULATE 8 "R3MWN" COL-LABEL="R3MWN" TABULATE 9 "R3MWW" COL-LABEL="R3MWW" TABULATE 10 "R1PDI" COL-LABEL="R1PDI" TABULATE 11 "R2PDI" COL-LABEL="R2PDI" TABULATE 12 "R3PDI" COL-LABEL="R3PDI" TABULATE 13 "RECY" COL-LABEL="RECYCLE" VARY STREAM-VAR STREAM=FEED SUBSTREAM=MIXED & VARIABLE=MASS-FLOW RANGE LOWER="1.0" UPPER="2.5" INCR="0.2" REINIT BLOCKS=ALL STREAMS=ALL

&

CONV-OPTIONS PARAM CHECKSEQ=NO SEQUENCE S-1 CSTR-1 CSTR-2 PLUG S1 CSTR-1 CSTR-2 PLUG DV-H1 FLASH-1 FLASH-2 (RETURN S1) STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC REACTIONS R1 FREE-RAD IN-UNITS SI DESCRIPTION "Free-Radical Kinetic Scheme" PARAM QSSA=YES SPECIES INITIATOR=TBP COINITIATOR=CINI MONOMER=STY & CHAINTAG=EB DDM POLYMER=PS MON-RSEG STY STY-SEG INIT-DEC TBP 1.6220E+11 1.1530E+08 0.0 EFFIC=.80 NRADS=2 INIT-SP STY CINI 438000.0 1.1480E+08 0.0 CHAIN-INI STY 1.0510E+07 2.9570E+07 0.0 PROPAGATION STY STY 1.0510E+07 2.9570E+07 0.0 CHAT-MON STY STY 3310000.0 5.3020E+07 0.0 CHAT-AGENT STY EB 1051.0 2.9590E+07 0.0 CHAT-AGENT STY DDM 1051.0 2.9590E+07 0.0 TERM-COMB STY STY 1.2550E+09 7017000.0 0.0 INIT-SP-EFF STY COEFFA=0.0 COEFFB=3.0 COEFFC=0.0 ;

&

Selected Simulation Results Results of the sensitivity studies carried out are shown in the figures that follow. As shown, since the overall residence time decreases when feed flow increases, conversion and polymer molecular weight decrease as well. Typically, for free-radical polymerization systems with chain transfer to monomer controlling the MWD, the polydispersity index should be close to 2. However, with termination by combination controlling the molecular weight, the polydispersity index should be close to 1.5. For this simulation the polydispersity increases to about 1.924, indicating that for the specified kinetics, the molecular weight becomes increasingly controlled by chain transfer to monomer at high conversion. Finally, since the monomer conversion decreases in the plug flow reactor, unreacted monomer recycle increases. Note, however, that the increase in styrene recycle flow is less than the increase in the overall feed flow rate. The effect of feed flow rate on styrene conversion is shown here:

1 0.9 n 0.8 o i s r 0.7 e v 0.6 n o 0.5 C e 0.4 n 0.3 e r y 0.2 t S 0.1 0 3000

CSTR-1 CSTR-2 PLUG

4 0 00

5000

60 0 0

7 00 0

8000

9 0 00

Feed Flow Rate, kg/hr

The effect of feed flow rate on the number average molecular weight is shown here:

128


200000 W M180000 e g a r e v 160000 A r e b 140000 m u N

CSTR-1 CSTR-2 PLUG

120000 3 00 0 4 0 00 5 0 0 0 6 0 0 0 7 0 0 0 8 0 0 0 90 0 0 Feed Flow R ate, kg/hr

The effect of flow rate on the weight average molecular weight is shown here:

350000 W M e 300000 g a r e v A t 250000 h g i e W 200000

CSTR-1 CSTR-2 PLUG

3000 4000 5000 6000 7000 8000 9000 Feed Flow Rate, R ate, kg/hr kg/hr

The effect of feed flow rate on the polydispersity index is shown here:

2 x e d 1.9 n I y t i s r 1.8 e p s i d y 1.7 l o P

CSTR-1 CSTR-2 PLUG

1.6 3 0 00 4 0 00 5 0 00 6 0 0 0 7 0 0 0 8 0 0 0 9 0 00 Feed Flow R ate, kg/hr

The effect of feed flow rate on the recycle flow rate is shown here:

r 1500 h / g k , e t 1000 a R w o l 50 0 F 500 e l c y c e 0 R

3000 4000 5000 6000 7000 8000 9000 Feed F low Rate, kg/hr kg/hr

Simulation Stream Summary A partial stream table for the i ntermediate process flowstreams is shown here: FEED PRODUCT R1-P R2-P R3-OLI ----------------------------STREAM ID

130

FEED

PRODUCT

R1-P

R2-P

R3-OLI


FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KG/HR TBP CINI STY PS EB DDM H2O COMPONENTS: MASS FRAC TBP CINI STY PS EB DDM H2O TOTAL FLOW: KMOL/HR KG/HR L/MIN STATE VARIABLES: TEMP C PRES BAR VFRAC LFRAC SFRAC ENTHALPY: KCAL/KMOL KCAL/KG KCAL/HR ENTROPY: CAL/MOL-K CAL/GM-K DENSITY: MOL/CC GM/CC AVG MW COMPONENT ATTRIBUTES: PS SFRAC STY-SEG SFLOW STY-SEG DPN DPN DPW DPW PDI PDI MWN MWN MWW

---CSTR-1

FLASH-2 ----

CSTR-1 CSTR-2

CSTR-2 PLUG

FLASH-1 FLASH-2

LIQUID

LIQUID

LIQUID

LIQUID

LIQUID

2.1000 0.0 6860.0000 0.0 133.0000 4.9000 0.0

0.0 0.0 147.1938 5645.3447 12.7095 3.9310 12.4952

1.2516 0.0 5147.1336 1713.7193 132.9956 4.8998 0.0

6.5145-02 0.0 2515.9679 4346.0858 132.9818 4.8993 0.0

0.0 0.0 485.4496 5645.3446 47.5461 4.4821 0.0

3.0000-04 0.0 0.9800 0.0 1.9000-02 7.0000-04 0.0

0.0 0.0 2.5284-02 0.9697 2.1831-03 6.7523-04 2.1463-03

1.7881-04 0.0 0.7353 0.2448 1.8999-02 6.9998-04 0.0

9.3065-06 0.0 0.3594 0.6209 1.8997-02 6.9990-04 0.0

0.0 0.0 7.8516-02 0.9131 7.6900-03 7.2493-04 0.0

67.1522 7000.0000 129.9401

56.4492 5821.6741 105.8946

67.1565 7000.0000 137.8228

67.1624 7000.0000 133.2545

59.3342 6182.8225 114.6276

25.0000 1.0133 0.0 1.0000 0.0

220.0000 1.0133 0.0 1.0000 0.0

120.0000 1.0133 0.0 1.0000 0.0

160.0000 1.0133 0.0 1.0000 0.0

220.0000 1.0133 0.0 1.0000 0.0

2.4055+04 230.7652 1.6154+06

2.1462+04 208.1063 1.2115+06

2.5663+04 246.2074 1.7235+06

2.3270+04 223.2675 1.5629+06

2.3116+04 221.8392 1.3716+06

-79.6026 -0.7636

-72.0269 -0.6984

-70.9953 -0.6811

-72.6021 -0.6966

-71.3946 -0.6851

8.6132-03 0.8978 104.2408

8.8845-03 0.9163 103.1312

8.1211-03 0.8465 104.2342

8.4003-03 0.8755 104.2250

8.6271-03 0.8990 104.2034

MISSING

1.0000

1.0000

1.0000

1.0000

MISSING

54.1828

16.4459

41.7088

54.1828

MISSING

1212.4496

1821.7072

1320.3382

1212.4496

MISSING

2309.3927

3177.1815

2469.6733

2309.3927

MISSING

1.9047

1.7441

1.8705

1.9047

MISSING

1.2628+05

1.8973+05

1.3752+05

1.2628+05

MWW ZMOM ZMOM FMOM FMOM SMOM SMOM LDPN LDPN LZMOM LZMOM LFMOM LFMOM LSFLOW STY-SEG LSFRAC STY-SEG LEFLOW STY-SEG LEFRAC STY-SEG LPFRAC LPFRAC

MISSING

2.4053+05

3.3091+05

2.5722+05

2.4053+05

MISSING

4.4689-02

9.0277-03

3.1589-02

4.4689-02

MISSING

54.1828

16.4459

41.7088

54.1828

MISSING

1.2513+05

5.2252+04

1.0301+05

1.2513+05

MISSING

568.1677

1170.7394

761.3834

568.1677

MISSING

2.9792-07

2.5496-07

3.2470-07

2.9792-07

MISSING

1.6927-04

2.9850-04

2.4722-04

1.6927-04

MISSING

1.6927-04

2.9850-04

2.4722-04

1.6927-04

MISSING

1.0000

1.0000

1.0000

1.0000

MISSING

2.9792-07

2.5496-07

3.2470-07

2.9792-07

MISSING

1.0000

1.0000

1.0000

1.0000

MISSING

6.6666-06

2.8242-05

1.0279-05

6.6666-06

References Albright, L.F. (1985). Processes for Major Addition-Type Plastics and Their Monomers. Monomers. Krieger Publishing Co. Brandrup, J., & Immergut, E. H. (1989). Polymer Handbook , 3rd Ed. Wiley Intersciences, 57-82. Friis, N., & Hamielec, A. E. (1976). Gel-Effect in Emulsion Polymerization of Vinyl Monomers. ACS Monomers. ACS Symp. Ser ., ., 24. 24. Gaur, U., & Wunderlich, B. (1982). J. (1982). J. Phys. Chem. Ref. Ref. Data, Data, 11, 11, (2), p. 313. Hui, A. W., & Hamielec, A. E. (1972). Thermal Polymerization of Styrene at High Conversions and Temperatures. An Experimental Study. J. of Applied Polymer Science, Science, 16, 16, pp. 9-769. Van Krevelen, D. W. (1990). Properties of Polymers, Their Correlation With Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions. New York: Elsevier. Van Krevelen, D. W. (1990). Properties of Polymers, Polymers , 3rd Ed., Amsterdam: Elsevier.

132


C2 Polystyrene with Styrene Monomer Distillation

The polystyrene with styrene monomer distillation model illustrates the use of Aspen Polymers Plus to model and predict the extent of polymer formation during styrene distillation. The model examines the optimum level of inhibitor to minimize polymer formation.

About This Process Product from a styrene plant consists of 63% styrene, 32% ethyl benzene and small amounts of toluene and benzene. Styrene is purified in a series of distillation columns. During distillation styrene polymerization occurs and the extent of polymerization depends on the t ime and temperature. To reduce polymer formation inhibitor is commonly used in the feed. The amount of inhibitor needs to be optimized since too little will produce more polymer waste and too high concentration of inhibitor will be expensive. The purpose of this example is to find an optimum level of inhibitor needed to minimize polymer formation and to maximize the process profitability.

Process Definition The process consists of three columns in series:

The first column, known as the BT column, removes benzene and toluene from the feed stream. The heavy cut flows to the EB (ethylbenzene) column, which takes off an ethylbenzene cut, which is recycled to the upstream styrene process. The third column separates the styrene monomer from residual polystyrene formed as a by-product in the columns. The reboiler of each column is represented using an RCSTR block (we assume that most of the polymer is formed in the column reboilers). We must use the RCSTR block because the current version of RadFrac does not support polymer reaction kinetics.

Process Conditions The process conditions are: Component

Name

Databank

Description

Styrene

STY

PURE12

Monomer

Etylbenzene

EB

PURE12


Benzene

BEN

PURE12

Solvent

Toluene

TOL

PURE12

Solvent

Inhibitor

INHIBIT

PURE12

Inhibitor

Coinitiator

CINI

--

Coinitiator

PS

PS

POLYMER

Polymer

STY-SEG

SEGMENT

Styrene segment

Feed Stream

134

Temperature

80 °C

Pressure

4.5 Bar

Mass Flow

18000 Kg/hr

Mass fraction of styrene

0.63


Mass fraction of ethyl benzene

0.318

Mass fraction of toluene

0.032

Mass fraction of benzene

0.02

Mass fraction of inhibitor

0.00


Block

Temp (C)

BT-COL

Pres (Bar) Top/Bottom

Specifications

0.24 / 0.4

30 ideal stages + condenser RR = 6.5 Feed - stage 20

BT-REB

109

EB-COL

0.4

Liquid holdup 22.5 m3

0.055 / 0.36

60 ideal stages + condenser RR = 10 Feed - stage 33

EB-REB

113

STY-COL

0.36

Liquid holdup 18.5 m3

0.05 / 0.092

10 ideal stages + condenser RR = 2.7 Feed - stage 2

STY-REB

100

0.092

Liquid holup 15 m3

Polymers and Segments Polystyrene is a homopolymer and the styrene segment is the only repeat unit. The set of component attributes required for free-radical polymerization is used for PS.

Physical Property Models and Data The Polymer Non-Random Two Liquid activity coefficient model (POLYNRTL) is used as the physical property method. Binary parameters for monomer/monomer pairs are drawn from Aspen’s binary databases. The monomer/styrene segment parameters are are set equal to the equivalent parameters for monomer/sytrene pairs. The thermophysical properties (density, heat capacity, etc.) of styrene, ethyl benzene, benzene, toluene and inhibitor are obtained from the Aspen Plus Pure Component Databank. Note that inhibitors are given the properties of styrene with the exception of molecular weight. The polymer thermophysical properties are calculated using the Van Krevelen group contribution method.

Reactors / Kinetics The specific reactions included from the built-in kinetics are: Description

Reaction

Thermal initiation

3M

Chain initiation

R* + M

Æ

P1

Propagation

Pn + M

Æ

Pn+1

Chain transfer to monomer

Pn + M

Æ

Dn + P1

Chain thansfer to EB

Pn + EB


Pn + Pm

Termination by inhibition

Pn + X

Æ

R*

Dn + P1

Æ Æ

Æ

Dn+m

Dn

The induced initiation reaction is configured for thermal initiation by setting third-order thermal initiation with respect to monomer. A coinitiator, which is required for the induced initiation reaction, is included in the list of components, but its feed rate is set to zero so that it will not influence the rate for the thermal initation reaction.

Inhibitor Common inhibitors used in this process are nitrobenzene, dinitro-o-bencene, dinitro-m-bencene, dinitro-p-bencene, 4,6 dinitro-o-cresol, etc. In this example 4,6 dinitro-o-cresol is used as inhibitor. (Mw = 198.135)

Process Studies Input Summary The input language summary for this example is shown here: TITLE 'STYRENE DISTILLATION' IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar DEF-STREAMS CONVEN ALL SIM-OPTIONS IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=bar TEMPERATURE=C DELTA-T=C & PDROP-PER-HT='mbar/m' PDROP=bar SIM-OPTIONS FLASH-TOL=1.0000E-06 DESCRIPTION “POLYSTYRENE IS FORMED IN THE REBOILER DURING THE DISTILLATION OF STYRENE. THIS EXAMPLE SHOWS HOW TO OPTIMIZE

136


THE AMOUNT OF INHIBITOR REQUIRED TO SUPRESS THE FORMATION OF POLYSTYRENE."

DATABANKS POLYMER / SEGMENT / PURE12 / AQUEOUS / INORGANIC / PURE93 / NOASPENPCD PROP-SOURCES POLYMER / SEGMENT / PURE12 SOLIDS / INORGANIC / PURE93

/ SOLIDS

/ AQUEOUS

/

&

&

COMPONENTS STY C8H8 / PS PS-1 / STY-SEG C8H8-R / EB C8H10-4 / BEN C6H6 / TOL C7H8 / INHIBIT C8H8 / CINI C8H8 FLOWSHEET BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK

BT-COL IN=BT-FEED BT-V1 OUT=BT-TOP BT-L1 BT-REB IN=BT-L1 OUT=BT-V1 BT-BOT EB-COL IN=EB-V1 EB-FEED OUT=EB-TOP EB-L1 EB-REB IN=EB-L1 OUT=EB-V1 EB-BOT PUMP-1 IN=BT-BOT OUT=EB-FEED PUMP-2 IN=EB-BOT OUT=STY-FEED STY-COL IN=STY-FEED STY-V1 OUT=STY-TOP STY-L1 STY-REB IN=STY-L1 OUT=STY-V1 RESIDUE

PROPERTIES POLYNRTL USER-PROPS GMRENA 1 2 1 / GMRENB 1 2 1 / GMRENC 1 2 1 / GMREND 1 2 1

&

PROP-DATA MW IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar PROP-LIST MW PVAL INHIBIT 198.1350 PROP-DATA PLXANT-1 IN-UNITS SI PRESSURE=bar TEMPERATURE=C PDROP='N/sqm' PROP-LIST PLXANT PVAL INHIBIT -30.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PROP-DATA NRTL-1 IN-UNITS ENG PROP-LIST NRTL BPVAL STY EB -.93850 48.950099610 .30 0.0 0.0 0.0 & 135.80600290 206.60000230 BPVAL EB STY 1.31730 -66.017519470 .30 0.0 0.0 0.0 &

135.80600290 206.60000230 BPVAL STY BEN 0.0 879.0049730 .3110 0.0 0.0 0.0 & 68.000003460 131.0000030 BPVAL BEN STY 0.0 -582.96797530 .3110 0.0 0.0 0.0 & 68.000003460 131.0000030 BPVAL EB BEN 0.0 51.711839590 .30340 0.0 0.0 0.0 & 176.00000260 275.00000180 BPVAL BEN EB 0.0 -64.163879490 .30340 0.0 0.0 0.0 & 176.00000260 275.00000180 BPVAL EB TOL 0.0 975.87575220 .30 0.0 0.0 0.0 & 212.00000230 273.20000180 BPVAL TOL EB 0.0 -654.62471480 .30 0.0 0.0 0.0 & 212.00000230 273.20000180 BPVAL BEN TOL 0.0 100.64771920 .30330 0.0 0.0 0.0 & 176.00000260 230.00000220 BPVAL TOL BEN 0.0 -109.82159910 .30330 0.0 0.0 0.0 & 176.00000260 230.00000220 POLYMERS SEGMENTS STY-SEG REPEAT POLYMERS PS ATTRIBUTES PS SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM & SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW LEFRAC & LPFRAC STREAM BT-FEED IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=bar TEMPERATURE=C & DELTA-T=C PDROP-PER-HT='mbar/m' PDROP=bar SUBSTREAM MIXED TEMP=80.0 PRES=4.50 MASS-FLOW=18000.0 MASS-FRAC STY .630 / EB .3180 / BEN .020 / TOL .0320 STREAM BT-L1 SUBSTREAM MIXED TEMP=107.746962 PRES=.40 & MASS-FLOW=25896.6115 MASS-FRAC STY .616547893 / EB .365240172 / BEN .008181312 / TOL .010030622

&

STREAM BT-V1 IN-UNITS MET MASS-FLOW='kg/sec' MOLE-FLOW='kmol/sec' & VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & TIME=sec VOLUME=cum DELTA-T=C HEAD=meter & MOLE-DENSITY='kmol/cum' MASS-DENSITY='kg/cum' & MOLE-ENTHALP='kcal/mol' MASS-ENTHALP='kcal/kg' & HEAT=MMkcal MOLE-CONC='mol/l' PDROP=bar SUBSTREAM MIXED TEMP=109 PRES=0.4 MASS-FLOW=2.15351197 MASS-FRAC STY 0.560602271 / EB 0.390454005 / BEN & 0.00198335909 / TOL 0.0469603649 STREAM EB-L1 SUBSTREAM MIXED TEMP=112.427233 PRES=.430 & MASS-FLOW=31872.8612 MASS-FRAC STY .619641479 / EB .369950341 / BEN 1.0888E-10 / TOL .000287885

&

STREAM EB-V1

138


SUBSTREAM MIXED PRES=0.36 VFRAC=1 MASS-FLOW=53891.635 MASS-FRAC STY 0.844267227 / EB 0.155732773 / TOL & 1.934753E-011 STREAM STY-L1 SUBSTREAM MIXED TEMP=83.8200436 PRES=.140 & MASS-FLOW=51412.4723 MASS-FRAC STY .985046601 / EB .001068554 / BEN 1.0782E-29 / TOL 1.9846E-14

&

STREAM STY-V1 SUBSTREAM MIXED PRES=0.092 VFRAC=1 MOLE-FLOW=341.040394 MASS-FRAC STY 0.994096437 / EB 0.00590356315 BLOCK BT-COL RADFRAC IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=bar TEMPERATURE=C & DELTA-T=C PDROP-PER-HT='mbar/m' PDROP=bar PARAM NSTAGE=30 ALGORITHM=STANDARD ABSORBER=NO COL-CONFIG CONDENSER=TOTAL REBOILER=NONE DIAGNOSTICS TERM=4 FEEDS BT-FEED 20 / BT-V1 31 PRODUCTS BT-TOP 1 L / BT-L1 30 L P-SPEC 1 .240 / 30 .40 COL-SPECS MOLE-RR=6.5 SC-REFLUX TEMP=40.0 OPTION=0 T-EST 1 43.0 / 2 57.0 / 22 113.0 BLOCK EB-COL RADFRAC PARAM NSTAGE=60 EFF=VAPOR COL-CONFIG CONDENSER=TOTAL REBOILER=NONE FEEDS EB-V1 61 / EB-FEED 33 PRODUCTS EB-TOP 1 L / EB-L1 60 L P-SPEC 2 .0650 / 60 .360 COL-SPECS MOLE-RR=10.0 SC-REFLUX TEMP=40.0 OPTION=0 BLOCK STY-COL RADFRAC PARAM NSTAGE=10 COL-CONFIG CONDENSER=PARTIAL-V REBOILER=NONE FEEDS STY-FEED 2 / STY-V1 11 PRODUCTS STY-TOP 1 V / STY-L1 10 L P-SPEC 1 .050 / 10 0.092 COL-SPECS MOLE-RR=2.70 BLOCK BT-REB RCSTR PARAM VOL=50.0 TEMP=109.0 PRES=0.0 NPHASE=2 PHASE=L PHASE-VOL=22.50 SCALING=COMPONENTS PRODUCTS BT-V1 V / BT-BOT L CONVERGENCE SOLVER=NEWTON REACTIONS RXN-IDS=R-1 BLOCK EB-REB RCSTR PARAM VOL=50.0 TEMP=113. PRES=0.0 NPHASE=2 PHASE=L PHASE-VOL=18.50 SCALING=COMPONENTS PRODUCTS EB-V1 V / EB-BOT L CONVERGENCE SOLVER=NEWTON

&

&

REACTIONS RXN-IDS=R-1 BLOCK STY-REB RCSTR PARAM VOL=50.0 TEMP=120.0 PRES=0.0 NPHASE=2 PHASE=L & PHASE-VOL=15.0 SCALING=COMPONENTS ALGORITHM=INTEGRATOR MAX-NSTEP=100 PRODUCTS STY-V1 V / RESIDUE L CONVERGENCE SOLVER=NEWTON REACTIONS RXN-IDS=R-1

&

BLOCK PUMP-1 PUMP PARAM PRES=4.130 BLOCK PUMP-2 PUMP PARAM PRES=6.20 EO-CONV-OPTI SENSITIVITY S-1 PARAM BASE-CASE=FIRST DEFINE INHI MASS-FRAC STREAM=BT-FEED SUBSTREAM=MIXED & COMPONENT=INHIBIT DEFINE R1PS MASS-FLOW STREAM=BT-BOT SUBSTREAM=MIXED & COMPONENT=PS DEFINE R2PS MASS-FLOW STREAM=EB-BOT SUBSTREAM=MIXED & COMPONENT=PS DEFINE R3PS MASS-FLOW STREAM=RESIDUE SUBSTREAM=MIXED & COMPONENT=PS DEFINE STY MASS-FLOW STREAM=BT-FEED SUBSTREAM=MIXED & COMPONENT=STY DEFINE FEEDI MASS-FLOW STREAM=BT-FEED SUBSTREAM=MIXED & COMPONENT=INHIBIT C F PS1 = R1PS / STY F PS2 = (R2PS - R1PS )/ STY F PS3 = (R3PS - R2PS )/ STY F PSTOT =R3PS/STY F PS0 = 731 / STY C F PPMIN = INHI * 1.0E6 C F P = PS0 - PSTOT C F PROFIT = P - 100 * FEEDI/STY TABULATE 1 "PPMIN" COL-LABEL="INHIBIT" "PPM" TABULATE 2 "PS1" COL-LABEL="PS1" "POLYMER" "BT-COL" TABULATE 3 "PS2" COL-LABEL="PS2" "POLYMER" "EB-COL" TABULATE 4 "PS3" COL-LABEL="PS3" "POLYMER" "STY-COL" TABULATE 5 "PSTOT" COL-LABEL="PSTOT" "TOTAL" "POLYMER" TABULATE 6 "PROFIT" COL-LABEL="PROFIT" VARY MASS-FLOW STREAM=BT-FEED SUBSTREAM=MIXED & COMPONENT=INHIBIT RANGE LIST=0.0 0.2 0.4 0.5 0.55 .60 0.65 0.7 0.75 1. & 2.0 3.0 CONV-OPTIONS PARAM TEAR-METHOD=BROYDEN CHECKSEQ=YES

140


STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC PROPERTY-REP PARAMS REACTIONS R-1 FREE-RAD IN-UNITS SI DESCRIPTION "FREE-RADICAL KINETIC SCHEME" PARAM QSSA=YES SPECIES COINITIATOR=CINI MONOMER=STY CHAINTAG=EB SOLVENT=TOL BEN INHIBITOR=INHIBIT POLYMER=PS MON-RSEG STY STY-SEG INIT-SP STY CINI 438000.0 1.1480E+08 CHAIN-INI STY 1.0510E+07 2.9570E+07 PROPAGATION STY STY 1.0510E+07 2.9570E+07 CHAT-MON STY STY 3310000.0 5.3020E+07 CHAT-AGENT STY EB 1051.0 2.9590E+07 TERM-COMB STY STY 1.2550E+09 7017000.0 INHIBITION STY INHIBIT 1.0500E+09 2.9570E+07 INIT-SP-EFF STY COEFFA=0.0 COEFFB=3.0 COEFFC=0.0

&

Selected Simulation Results This example includes a sensitivity study in which the inhibitor feed rate is adjusted over a wide range. The purpose of this sensitivity is to find an optimum level of inhibitor needed to minimize polymer formation and to maximize the process profitability. Process profitability is calculated as follows with the assumption that inhibitor is 100 times more expensive than styrene monomer: PROFIT = PS0 - PSTOT - 100 * FEEDI / STY Where: PS0

= Mass flow of polymer produced without inhibitor in the feed / Mass flow of styrene in the feed

PSTOT

= Mass flow of polymer produced with inhibitor in the feed / Mass flow of styrene in the feed

FEEDI

= Mass flow of inhibitor in the feed

STY

= Mass flow of styrene in the feed

Results of the sensitivity studies are shown in the table and figures that follow. Effect of Inhibitor Feed Mass Fraction on the Polymer F ormation and Process Profitability VARY 1

INHIBIT

PS1

PS2

PS3

PSTOT

BT-FEED

PPM

POLYMER

POLYMER

POLYMER

TOTAL

BT-COL

EB-COL

STY-COL

POLYMER

MIXED INHIBIT MASSFLOW KG/HR

PROFIT

1

0.00

0.00

3.08E-02

3.89E-02

3.20E-04

0.07003

-0.0056

2

0.20

11.11

1.70E-02

3.28E-02

3.72E-05

0.04987

0.0128

3

0.40

22.22

7.52E-03

1.26E-02

2.98E-06

0.02017

0.0408

4

0.50

27.78

5.50E-03

3.77E-04

1.80E-07

0.00588

0.0542

5

0.55

30.55

4.83E-03

2.13E-04

1.51E-07

0.00505

0.0546

6

0.60

33.33

4.30E-03

1.47E-04

1.40E-07

0.00445

0.0547

7

0.65

36.11

3.87E-03

1.13E-04

1.35E-07

0.00398

0.0547

8

0.70

38.89

3.52E-03

9.34E-05

1.32E-07

0.00361

0.0547

9

0.75

41.66

3.22E-03

8.05E-05

1.30E-07

0.00330

0.0545

10

1.00

55.55

2.27E-03

5.44E-05

1.28E-07

0.00232

0.0533

11

2.00

111.10

1.04E-03

4.49E-05

1.46E-07

0.00109

0.0457

12

3.00

166.64

6.82E-04

5.06E-05

1.80E-07

0.00073

0.0373

The effect of the inhibitor feed mass fraction on polymer production is shown here:

7 0 . 0 6 0 . 0 5 0 . 0 4 0 . 0 3 0 . 0 2 0 . 0 1 0 . 0 0

PS Generated in BT Column, kg/hr PS Generated in EB Column, kg/hr PS Generated in Styrene Column, kg/hr Total PS Residue, kg/hr

15

30 45 60 75 90 105 120 135 150 165 Inhibitor Concentration in feed, PPM

The effect of the inhibitor feed mass fraction on process profitability is shown here:

142


5 4 0 . 0 3 0 . 0 5 1 0 . 0

Profit

0

0

10 20 30 40 50 60 70 80 90 100 110 Concentration of Inhibitor in Feed, PPM

Simulation Stream Summary The stream summary report (for selected streams) for the base case results without inhibitor is shown here: STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR STY PS EB BEN TOL INHIBIT CINI COMPONENTS: KG/HR STY PS EB BEN TOL INHIBIT CINI COMPONENTS: MASS FRAC STY PS EB BEN TOL INHIBIT CINI

BT-FEED ---BT-COL

BT-TOP BT-COL ----

BT-BOT BT-REB PUMP-1

EB-TOP EB-COL ----

EB-BOT EB-REB PUMP-2

LIQUID

LIQUID

LIQUID

LIQUID

LIQUID

108.8798 0.0 53.9149 4.6087 6.2513 0.0 0.0

4.1382-07 0.0 9.0635-05 4.5123 2.5789 0.0 0.0

105.5295 3.3508 53.9148 9.6354-02 3.6725 0.0 0.0

88.5771 0.0 53.9138 9.6354-02 3.6725 0.0 0.0

12.7131 7.5900 9.7391-04 0.0 0.0 0.0 0.0

1.1340+04 0.0 5724.0000 360.0000 576.0000 0.0 0.0

4.3100-05 0.0 9.6225-03 352.4725 237.6205 0.0 0.0

1.0991+04 348.9875 5723.9916 7.5265 338.3835 0.0 0.0

9225.4371 0.0 5723.8877 7.5265 338.3835 0.0 0.0

1324.0935 790.5152 0.1034 0.0 0.0 0.0 0.0

0.6300 0.0 0.3180 2.0000-02 3.2000-02 0.0 0.0

7.3038-08 0.0 1.6306-05 0.5973 0.4027 0.0 0.0

0.6313 2.0045-02 0.3288 4.3231-04 1.9436-02 0.0 0.0

0.6032 0.0 0.3742 4.9208-04 2.2123-02 0.0 0.0

0.6261 0.3738 4.8894-05 0.0 0.0 0.0 0.0

TOTAL FLOW: KMOL/HR 173.6547 KG/HR 1.8000+04 CUM/HR 21.5234 STATE VARIABLES: TEMP C 80.0000 PRES BAR 4.5000 VFRAC 0.0 LFRAC 1.0000 SFRAC 0.0 ENTHALPY: KCAL/MOL 17.3942 KCAL/KG 167.8099 MMKCAL/HR 3.0206 ENTROPY: CAL/MOL-K -77.8169 CAL/GM-K -0.7507 DENSITY: KMOL/CUM 8.0682 KG/CUM 836.3005 AVG MW 103.6540 COMPONENT ATTRIBUTES: PS SFRAC STY-SEG MISSING SFLOW STY-SEG MISSING DPN DPN MISSING DPW DPW MISSING PDI PDI MISSING MWN MWN MISSING MWW MWW MISSING ZMOM ZMOM MISSING FMOM FMOM MISSING SMOM SMOM MISSING LDPN LDPN MISSING LZMOM LZMOM MISSING LFMOM LFMOM MISSING LSFLOW STY-SEG MISSING LSFRAC STY-SEG MISSING LEFLOW STY-SEG MISSING LEFRAC STY-SEG MISSING LPFRAC

144

7.0913 590.1027 0.6919

166.5639 1.7410+04 21.4214

146.2597 1.5295+04 17.5462

20.3042 2114.7121 2.4217

40.0000 0.2400 0.0 1.0000 0.0

109.0000 0.4000 0.0 1.0000 0.0

40.0000 6.5000-02 0.0 1.0000 0.0

113.0000 0.3600 0.0 1.0000 0.0

9.0202 108.3966 6.3966-02

18.9151 180.9639 3.1506

14.5519 139.1518 2.1284

24.3632 233.9206 0.4947

-65.1477 -0.7829

-75.2613 -0.7200

-85.4707 -0.8173

-73.7515 -0.7081

10.2491 852.8781 83.2152

7.7756 812.7352 104.5242

8.3357 871.7124 104.5759

8.3842 873.2279 104.1516

MISSING

1.0000

MISSING

1.0000

MISSING

3.3506

MISSING

7.5899

MISSING

2661.1066

MISSING

2728.7708

MISSING

4974.3601

MISSING

5043.0428

MISSING

1.8693

MISSING

1.8481

MISSING

2.7716+05

MISSING

2.8421+05

MISSING

5.1809+05

MISSING

5.2524+05

MISSING

1.2591-03

MISSING

2.7814-03

MISSING

3.3506

MISSING

7.5899

MISSING

1.6667+04

MISSING

3.8276+04

MISSING

1981.7638

MISSING

1974.7946

MISSING

1.8832-07

MISSING

2.7918-08

MISSING

3.7321-04

MISSING

5.5133-05

MISSING

3.7321-04

MISSING

5.5133-05

MISSING

1.0000

MISSING

1.0000

MISSING

1.8832-07

MISSING

2.7918-08

MISSING

1.0000

MISSING

1.0000


LPFRAC

MISSING

MISSING

RESIDUE STY-REB ----

STY-TOP STY-COL ----

LIQUID

VAPOR

0.6196 7.6249 2.2485-06 0.0 0.0 0.0 0.0

12.0586 0.0 9.7166-04 0.0 0.0 0.0 0.0

64.5362 794.1484 2.3872-04 0.0 0.0 0.0 0.0

1255.9241 0.0 0.1032 0.0 0.0 0.0 0.0

7.5157-02 0.9248 2.7801-07 0.0 0.0 0.0 0.0

0.9999 0.0 8.2131-05 0.0 0.0 0.0 0.0

8.2446 858.6848 0.8909

12.0596 1256.0273 6647.3689

120.0000 9.2000-02 0.0 1.0000 0.0

59.1993 5.0000-02 1.0000 0.0 0.0

18.2651 175.3702 0.1506

36.2480 348.0308 0.4371

-82.6169 -0.7932

-43.9790 -0.4223

9.2543 963.8521 104.1515

1.8142-03 0.1890 104.1517

RESIDUE STY-TOP --------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR STY PS EB BEN TOL INHIBIT CINI COMPONENTS: KG/HR STY PS EB BEN TOL INHIBIT CINI COMPONENTS: MASS FRAC STY PS EB BEN TOL INHIBIT CINI TOTAL FLOW: KMOL/HR KG/HR CUM/HR STATE VARIABLES: TEMP C PRES BAR VFRAC LFRAC SFRAC ENTHALPY: KCAL/MOL KCAL/KG MMKCAL/HR ENTROPY: CAL/MOL-K CAL/GM-K DENSITY: KMOL/CUM KG/CUM AVG MW

1.4957-04

MISSING

1.0037-05

COMPONENT ATTRIBUTES: PS SFRAC STY-SEG SFLOW STY-SEG DPN DPN DPW DPW PDI PDI MWN MWN MWW MWW ZMOM ZMOM FMOM FMOM SMOM SMOM LDPN LDPN LZMOM LZMOM LFMOM LFMOM LSFLOW STY-SEG LSFRAC STY-SEG LEFLOW STY-SEG LEFRAC STY-SEG LPFRAC LPFRAC

1.0000

MISSING

7.6248

MISSING

2730.8645

MISSING

5049.0638

MISSING

1.8489

MISSING

2.8442+05

MISSING

5.2587+05

MISSING

2.7921-03

MISSING

7.6248

MISSING

3.8498+04

MISSING

2711.1368

MISSING

6.6782-10

MISSING

1.8106-06

MISSING

1.8106-06

MISSING

1.0000

MISSING

6.6782-10

MISSING

1.0000

MISSING

2.3919-07

MISSING

References Scheeline, H. W., & Pons, J. I. I . (1977). Styrene, Supplement B (Process Economics Program Report No. 33B). Menlo Park: Stanford Research Institute.

146


C3 Expanded Polystyrene Suspension Polymerization

The expanded polystyrene polystyrene (EPS) suspension polymerization polymerization model illustrates the use of Aspen Polymers Plus for modeling free-radical suspension polymerization of styrene in a batch reactor. The batch reactor model, RBatch, rigorously accounts accounts for two liquid phases and one vapor phase. The reactions take place in the organic (monomer/polymer droplets) phase. The first polymerization stage of the EPS process and the effect of n-pentane on the conversion and molecular weight profiles are studied. The results reproduce the published work of Villalobos and coworkers (1993). This application example also compares the use of monofunctional and bifunctional initiators. Note that Aspen Polymers Plus currently does not support bifunctional initiators.

About This Process The manufacture of expandable polystyrene involves two stages. During the first stage, suspension polymerization of styrene is carried out in a stirred batch reactor at temperatures between 80 and 90°C with a dispersed phase hold-up (volume of monomer phase over total liquid volume) in the range of 0.4 to 0.6. Styrene monomer is suspended in the form of droplets in water phase. Polymerization occurs in these droplets until the mixture reaches its glass transition temperature. The mean particle size is determined by the droplet coalescence and the droplet breakage caused by the agitation system. The particle growth is controlled with the aid of suspending agents, which are usually inorganic powders such as tricalcium phosphate. In the second stage, also known as the impregnation stage, a blowing agent, such as n-pentane, is loaded into the reactor and diffuses into the beads. The residual monomer is polymerized using an initiator with a half-life higher than the one used in the polymerization process. The batch reactor is operated at elevated pressures during this second, impregnation, stage. A main manufacturing objective is to minimize the long batch times necessary to complete the polymerization. Polymerization at higher temperatures as a

means to increase productivity is not successful due to lower molecular weight of the polymer and the enhanced particle coalescence, coalescence, which is due to the higher temperature. Addition of a blowing agent influences the polymerization rate and the molecular weight. The objective of plant engineers is to optimize the time of the blowing agent addition and the extent of initiator needed to improve the overall productivity. The Aspen Plus RBatch reactor model is used to simulate the batch polymerization. The EPS process involves two liquid phases (monomer and water) and one vapor phase, which is rigorously handled inside RBatch. All polymerization reactions (initiation, propagation, termination, and chain transfer) occur in the monomer rich phase. This is specified using a phase identifier in the free-radical kinetic model. Initiator decomposition and thermal initiation in the monomer droplets generate radicals that polymerize the monomer. The polymer is soluble in the monomer phase. As the monomer concentration drops, the onset of diffusion controlled termination leads to an auto-acceleration or gel effect, which increases the reaction rate. At high conversion, the polymer monomer mixture becomes glassy, and the propagation reaction becomes diffusion limited. This effect is known as the glass effect. The model is used to study the effect of adding n-pentane at the beginning of the polymerization. N-pentane is a stronger electron donor than styrene, and addition of n-pentane leads to a reduction in chain transfer to monomer. By using user-gel effect correlations, the model captures the effect of n-pentane on chain transfer, gel effect, and glass effect.

Process Definition The first stage of the EPS suspension polymerization process is modeled using the batch reactor model, RBatch. The recipe is defined in terms of concentrations at 25ºC in the monomer phase. Therefore, the charge stream, which is specified in overall concentrations, is fed to a three-phase block at 25°C. The charge of individual components is adjusted until the equilibrium concentrations in the monomer phase match the required recipe and the dispersed phase volume fraction equals 0.4. All streams from the Flash3 block are then passed to a heater that heats the charge stream to the initial reaction temperature.

148

C3 Expanded Polystyrene Suspension Polymeriza Polymerization tion

Process Conditions The batch reactor feed time is specified at one hour so that the charge flow rate on an hourly basis is equivalent to the actual charge. After the execution of the Flash3 block, a calculator block computes phi (the dispersed phase holdup) and initator and pentane concentrations. The reaction occurs at constant temperature (90ºC) and pressure (275 Kpa for pentane=0 case, and 825 Kpa for pentane cases). Note: In the delivered model, the calculator block is hidden. If the calculator block is revealed, a Fortran compiler is required to run the example. The process conditions are: Components

Name

Databank

Description

Styrene

STY

PURE11

Monomer

Polystyrene

PS STY-SEG

POLYMER SEGMENT

Polymer component Styrene segment

Benzoyl peroxide

BPO

---

Initiator (Mw=242.23) (Mw=242.23)

Coinitiator

CINI

---

Coinitiator (zero concentration, required for thermal initiation)

n-pentane

NPENTANE

PURE11

Blowing agent

Water

H2O

PURE11

Suspension medium

Physical Properties

POLYNRTL property method with supplied parameters

Recipe Initial volume at 25ºC (cc)

3200

Dispersed phase volume fraction at 25ºC

0.4

Inititiator concentration (kmol/m3)

0.01

n-Pentane concentration

0.0, 7.5, 15

(wt%, with regard to styrene) Charge Temperature (°C)

90

Pressure (KPa)

275 (n-pentane=0), 825 (n-pentane>0) 3

Volume Flow (m /hr)

3.2E-3

Mass parts of initiator

.27

Mass parts of polystyrene

0.0

Mass parts of coinitiator

0.0

Mass parts of monomer

100, 92.5, 85

Mass parts of water

170.1

Mass parts of n-pentane

0.0, 7.5, 15

Kinetics

FREE-RAD model (options specify reactions in L1 phase only)


Block

Temp ( C)

Pres

FLASH3

25

= Charge

HEATER

90

= Charge

BATCH

90

= Charge

Physical Property Models and Data The Polymer Non-Random Two Liquid activity coefficient model physical property method (POLYNRTL) is used. The thermophysical properties (density, heat capacity, etc.) of styrene, n-pentane, and water are obtained from the Aspen Plus Pure Component Databank. Note that initiator and coinitiator are given the properties of styrene with the exception of molecular weight. The polymer thermophysical properties are calculated using the van Krevelen group contribution method.

Reactors / Kinetics The kinetics of suspension EPS are similar to those of the bulk polystyrene (See C1 Polystyrene Bulk Polymerization Polymerization by Thermal Thermal Initiation application example). The reactions included from the free-radical built-in kinetics are: Description

Reaction

Thermal initiation

3 M


I

→ 2R

→ 2R

•

•

Chain initiation Propagation Chain transfer to monomer Termination by combination

The units for the rate constants for the thermal initiation reaction are m6 /kmol2 /s. For initiator decomposition decomposition the units are /s. /s. The units for the rate 3 2 constants for the other reactions are m /kmol /s. Thermal initiation is defined using the special initiation reaction and by setting third-order thermal initiation with respect to monomer. A coinitiator, which is required for the special initiation reaction, is included in the list of components, but its feed rate is set to zero so that it will not influence the rate for the thermal initiation reaction. As mentioned previously, the gel and glass effects are modeled using a user gel effect correlation:

150

Description

Correlation Number

Termination (gel effect)

4

Propagation (glass effect)

5


3


(effect of n-pentane on)

The correlations contained within the user Fortran routine, usrgel.f, calculate the gel factor for each of these reactions using the free volume theory described by Villalobos (1993). The gel factor is multiplied with the rate constant calculated from the pre-exponental and activation energy to give the diffusion limited rate constant.

Process Studies The model is used to study the effect of initial n-pentane concentration on conversion and molecular weight profiles.

Input Summary An input language summary for this example is shown here: TITLE 'SUSPENSION EXPANDED POLYTSTYRENE BATCH PROCESS' IN-UNITS SI OUT-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar DEF-STREAMS CONVEN ALL DIAGNOSTICS HISTORY SIM-LEVEL=4 SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=2000.0 ; ; ;

THE COMPONENT SYSTEM DEFINITION FOLLOWS

DESCRIPTION " EXPANDED POLYSTYRENE SUSPENSION POLYMERIZATION BATCH PROCESS. THIS EXAMPLE USES THE KINETIC MODEL AND RATE CONSTANTS DESCRIBED IN VILLALOBOS,M.A.,HAMIELEC,A.E,AND WOOD, P.E.,BULK AND SUSPENSION POLYMER IZATION OF STYRENE IN THE PRESENCE OF N-PENTANE. AN EVALUATION OF MONO FUNCTIONAL AND BIFUNCTIONAL INITIATION, J.APPL.POLYM.SCI,50,327-343 (19 93) " DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12 COMPONENTS

/ SEGMENT

/ POLYMER

/ ASPENPCD

/ SEGMENT

/ ASPENPCD

BPO C8H8 / CINI C8H8 / STY C8H8 / PS PS-1 / STY-SEG C8H8-R / WATER H2O / NPENTANE C5H12-1 FLOWSHEET BLOCK BATCH IN=4 OUT=PRODUCT BLOCK FLASH3 IN=CHARGE OUT=1 2 3 BLOCK HEATER IN=1 2 3 OUT=4 PROPERTIES POLYNRTL PROP-DATA DATA1 IN-UNITS SI PROP-LIST MW PVAL BPO 242.230 PROP-DATA PLXANT-1 IN-UNITS SI PROP-LIST PLXANT PVAL PS -10.0 PROP-DATA NRTL-1 IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=K & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar PROP-LIST NRTL BPVAL BPO WATER -176.71520 10542.57030 .20 0.0 25.52320 & 0.0 279.150 338.150 BPVAL WATER BPO 150.57740 -5675.06590 .20 0.0 -21.68180 & 0.0 279.150 338.150 BPVAL CINI WATER -176.71520 10542.57030 .20 0.0 25.52320 & 0.0 279.150 338.150 BPVAL WATER CINI 150.57740 -5675.06590 .20 0.0 -21.68180 & 0.0 279.150 338.150 BPVAL STY WATER -176.71520 10542.57030 .20 0.0 25.52320 & 0.0 279.150 338.150 BPVAL WATER STY 150.57740 -5675.06590 .20 0.0 -21.68180 & 0.0 279.150 338.150 BPVAL STY-SEG WATER 0.0 500.0 .30 0.0 0.0 0.0 0.0 & 1000.0 BPVAL WATER STY-SEG 0.0 500.0 .30 0.0 0.0 0.0 0.0 & 1000.0 BPVAL WATER NPENTANE 12.38660 -791.79130 .20 0.0 0.0 0.0 & 273.150 303.150 BPVAL NPENTANE WATER -10.68920 5051.72750 .20 0.0 0.0 0.0 & 273.150 303.150 POLYMERS SEGMENTS STY-SEG REPEAT POLYMERS PS

152


ATTRIBUTES PS DPN DPW PDI MWN MWW ZMOM FMOM SMOM SFLOW SFRAC

&

PROP-SET PS-1 MASSFRAC SUBSTREAM=MIXED COMPS=PS PHASE=L1 PROP-SET VOLFLOW VOLFLMX UNITS='cum/hr' SUBSTREAM=MIXED PHASE=T STREAM CHARGE IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar SUBSTREAM MIXED TEMP=25.0 PRES=8.250 VOLUME-FLOW=.00320 & FREE-WATER=NO NPHASE=3 PHASE=V MASS-FRAC BPO .2780 / STY 100.0 / WATER 170.10 BLOCK HEATER HEATER IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar PARAM TEMP=90.0 PRES=0.0 NPHASE=3 BLOCK-OPTION FREE-WATER=NO BLOCK FLASH3 FLASH3 IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar PARAM TEMP=25.0 PRES=0.0 BLOCK BATCH RBATCH IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr' & HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar PARAM TYPE=T-SPEC PRINT-TIME=.166666667 FEED-TIME=1.0 & MAX-TIME=8.0 MAX-NPOINT=50 PRES=2.750 TEMP=90.0 & NPHASE=3 FLASH=YES STOP 2 REACTOR TIME 8.0 PROP-REACTOR PS-1 BLOCK-OPTION TERM-LEVEL=6 FREE-WATER=NO REACTIONS RXN-IDS=R1 L2-COMPS COMP-LIST=WATER EO-CONV-OPTI CALCULATOR PHI IN-UNITS MET VOLUME-FLOW='cum/hr' ENTHALPY-FLO='MMkcal/hr'

&

F F F

HEAT-TRANS-C='kcal/hr-sqm-K' PRESSURE=bar TEMPERATURE=C & VOLUME=cum DELTA-T=C HEAD=meter MOLE-DENSITY='kmol/cum' & MASS-DENSITY='kg/cum' MOLE-ENTHALP='kcal/mol' & MASS-ENTHALP='kcal/kg' HEAT=MMkcal MOLE-CONC='mol/l' & PDROP=bar DEFINE VL1 STREAM-PROP STREAM=2 PROPERTY=VOLFLOW DEFINE VLTOT STREAM-PROP STREAM=CHARGE PROPERTY=VOLFLOW DEFINE BPO MOLE-FLOW STREAM=2 SUBSTREAM=MIXED COMPONENT=BPO DEFINE NC5 MASS-FRAC STREAM=2 SUBSTREAM=MIXED & COMPONENT=NPENTANE WRITE(*,*) 'PHI =',VL1/VLTOT WRITE(*,*) '[I]O =',BPO/VL1,' MOL/L-STYRENE' WRITE(*,*) '[C5]O =',NC5*100,' WT%(WRT STYRENE)' EXECUTE AFTER BLOCK FLASH3

CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC PROPERTIES=PS-1 VOLFLOW REACTIONS R1 FREE-RAD IN-UNITS MET DESCRIPTION "EXAMPLE FREE-RADICAL INPUT" PARAM QSSA=YES SPECIES INITIATOR=BPO COINITIATOR=CINI MONOMER=STY & POLYMER=PS MON-RSEG STY STY-SEG INIT-DEC BPO 3.8160E+12 27233.0 0.0 EFFIC=.60 NRADS=2 INIT-SP STY CINI 219000.0 27440.0 0.0 CHAIN-INI STY 1.0213E+07 7068.0 0.0 PROPAGATION STY STY 1.0213E+07 7068.0 0.0 CHAT-MON STY STY 1.0213E+07 13450.0 0.0 TERM-COMB STY STY 1.2583E+09 1677.0 0.0 INIT-SP-EFF STY COEFFA=0.0 COEFFB=3.0 COEFFC=0.0 GEL-EFFECT TERMINATION 4 MAX-PARAMS=3 GE-PARAMS=.50 .3480 & 1.750 GEL-EFFECT PROPAGATION 5 MAX-PARAMS=2 GE-PARAMS=1.0 .04650 GEL-EFFECT CHAT-MON 3 MAX-PARAMS=1 GE-PARAMS=1.750 SUBROUTINE GEL-EFFECT=USRGEL OPTIONS PHASE=L1;

Selected Simulation Results The effect of initial n-pentane concentration on conversion is shown hereT:

154


1 0.9 0.8 0.7

n o 0.6 i s r e 0.5 v n 0.4 o C0.3 0.2 0.1 0 0

1

2

3

4

5

6

7

8

Time(hours) n-pentane=0

n-pentane=7.5%

n-pentane=15%

As shown, the auto-accleration (gel) effect is apparent in the case with no npentane: the slope of the conversion curve increases at about 6 hours. The glass effect, which results in a flattening of the curve as the propagation rate constant is decreased when the polymer mixture becomes glassy, is also shown. The other two curves show that neither the gel effect nor the glass effect is reached due to the plasticizing effect of the n-pentane. The number and weight average molecular weights for the three n-pentane cases are shown here: 300 275

) 250 s d225 n200 a175 s u150 o h w125 T ( M , 100 n 75 M50 25 0 0

0. 1

0. 2

0. 3

0. 4

0. 5

0. 6

0. 7

0. 8

0. 9

1

Conversion npent ane=0

npent ane=0

n- pent ane=15%

n- pent ane=15%

npent ane=7. 5%

npent ane=7. 5%

One would expect the addition of a solvent to reduce the molecular weight. However, the n-pentance reduces this effect by lowering the chain transfer to monomer rate. Additionally, because it is a stronger electron donor than styrene, n-pentane can obstruct the hydrogen abstraction necessary for chain transfer to solvent to occur. Therefore, n-pentane addition leads to a molecular weight build-up in the system.

References Villalobos, M. A., Hamielec,A. E., & Wood, P. E. (1993). Bulk and Suspension Polymerization of Styrene in the Presence of n-Pentane. An Evaluation of Monofunctional and Bifunctional Initiation. J. Initiation. J. Appl. Polym. Sci., 50, 50, 327-343.

156


C4 Styrene Ethyl Acrylate Free-Radical Copolymerization Process

The styrene ethyl acrylate free-radical copolymerization model illustrates the use of Aspen Polymers Plus to model a styrene ethyl acrylate free-radical process. The process modeled is an experimental system developed by McManus and Penlidis at the University of Waterloo. The model is then used along with the experimental data generated at the University of Waterloo to estimate reaction rate constant parameters.

About This Process The copolymerization of styrene with ethyl acrylate is of considerable interest to the polymer industry. In 1996, McManus and Penlidis from the University of Waterloo reported a detailed study of the copolymerization of styrene and ethyl acrylate, and generated extensive data by varying the initiator concentration, feed composition, and the reactor temperature (McManus & Penlidis, 1996). Similar studies have been done for this system (Fehervari et al., 1981). A number of investigators estimated the kinetic parameters, but there are many discrepancies between kinetic rate constants and the reactivity ratios reported in the literature. McManus and Penlidis reviewed the information available on the kinetic data and estimated the reactivity ratios.

Process Definition The copolymerization of styrene and ethyl acrylate is carried out in a batch reactor. The batch reactor is charged with a pre-mixed stream of styrene, ethyl acrylate, and the initiator azo-bis-isobutyronitrile. The reactor is operated at a constant temperature and pressure. The flowsheet is shown here:

Process Conditions The process conditions are: Components

Name

Databank

Description

Initiator

AIBN

PURE12

Initiator

Styrene

STY

PURE12

Monomer

Ethyl Acrylate

EA

PURE12

Monomer

Polymer

POLYMER

POLYMER

Polymer

STY-SEG

SEGMENT

Styrene segment

EA-SEG

SEGMENT

Ethyl Acrylate segment

Physical Properties

POLYNRTL property method

Stream

Monomer

Initiator

Temperature (°C)

60

60

Pressure (atm)

1

1

Mass flow kg/h

1000

Mole flow of AIBN

0.05 MR/L in reaction mixture

Mole fraction of styrene

0.762

Mole fraction of ethyl acrylate

0.238

Kinetics

FREE-RAD model

Operating Conditions BATCH reactor Temperature (°C)

60

Pressure (atm)

1

Reaction time (hr)

25

Cycle time (hr)

1

Reactors / Kinetics The reaction set used in this process and the initial rate constant parameters are: Description

158

k0 (m3/kmol)

Ea (J/kmol)

V (m3/kmol)

EFFIC

C4 Styrene Ethyl Acrylate Free-R Free-Radical adical Copolymeriz Copolymerization ation Process

INIT-DEC AIBN

1.82E15

1.288E8 E

0.0

CHAIN-INI STY

4.5E6

2.6E7

0.0

CHAIN-INI EA

3.0E6

2.24E7

0.0

PROPAGATION STY STY

2.3438E6

2.6E7

0.0

PROPAGATION STY EA

3.26562E6

2.6E7

0.0

PROPAGATION EA STY

1.49182E7

2.24E7

0.0

PROPAGATION EA EA

3.000E6

2.24E7

0.0

CHAT-MON STY STY

117.190

2.6000E+0 7

0.0

CHAT-MON STY EA

163.30

2.6000E+0 7

0.0

CHAT-MON EA STY

746.0

2.2400E+0 7

0.0

CHAT-MON EA EA

95.50

2.2400E+0 7

0.0

TERM-COMB STY STY

1.4592E9

7E6

0.0

TERM-COMB STY EA

6.63E10

14.6E6

0.0

TERM-COMB EA STY

6.63E10

14.6E6

0.0

TERM-COMB EA EA

3.00E10

22.2E6

0.0

0.5080 8

Gel effect is applied to t o the initiator efficiency and termination reaction using correlation No. 2. Reaction

Correlation

Parameters

INIT-EFF

2

-17.40 0.05528 17.8240 -05090 0.0 0.0 0.0 0.0 0.0 2.0

TERMINATION

2

1.0 0.0 2.570 -.005050 9.560 -.01760 -3.030 .007850 0.0 2.0

Parameter Regression The experimental data reported by McManus and Penlidis includes conversion, polymer composition, and number and weight average molecular weights as a function of time. This data was generated by varying: varying: (1) the initial mole ratio of styrene to EA, (2) the initiator concentration, and (3) the reactor temperature. The DATA-FIT capability is used to fit the reaction rate constant parameters. Monomer conversion and number average molecular weights were used to regress the kinetic parameters. The experimental data obtained at 50 and 60°C is provided in the following two tables. To indicate the accuracy of the experiments, data obtained with a replicate experiment are also included in the tables. T=50 C, Styrene Mole Fraction in the feed=0.762, and AIBN=0.05 mol/L Data used in Data-Fit

Replicate Experiment

Simulation Results

Time (min)

Conversion (mass %)

Molecular Weight (Mn)

Conversion (mass %)


Conversion (mass %)


0

0

9.61E+04

0

0.00E+00

0

92990

120

5.68

9.61E+04

5.62

98204

5.36

92990

240

10.79

9.69E+04

11.58

84913

10.6

95576.3

360

16.09

9.85E+04

16.48

89791

15.82

98699.5

480

21.06

1.02E+05

21.86

99669

21.11

1.02E+05

600

26.16

1.02E+05

26.82

99269

26.55

1.07E+05

28.63

101179

660 720

37.55

1.04E+05

32.3

97121

32.25

1.12E+05

840

36.6

1.05E+05

37.08

105809

38.33

1.18E+05

41.8

106172

42.82

101569

44.98

1.26E+05

52.44

1.35E+05

61.08

1.46E+05

71.37

1.60E+05

1440

83.38

1.78E+05

1560

94.04

1.92E+05

98.37

1.94E+05

900 930

39.36

960 1020

1.12E+05 1.12E+05

45.97

1080 1110

54.68

1.12E+05

1200

61.44

1.15E+05

1290

68.66

1.35E+05

56.22 70.71

99967 108848

1320 1410

1620

77.46

97.44

1.34E+05

79.37

142398

1.21E+05

1680 1760

99.5

201441

T=60 C, Styrene Mole Fraction in the feed=0.762, and AIBN=0.05 mol/L

160


Data used in Data-Fit

Replicate Experiment

Simulation Results

Time (min)

Conversion (mass %)


Conversion (mass %)


Conversion (mass %)


0

0

6.13E+04

0.00E+00

53353

0

60149

60

7.73

6.13E+04

6.9

60149

13.44

63142

90

5.62

53353

120

14.16

6.34E+04

180

21.14

6.73E+04

11.58

58819

19.788

66606

240

27.25

6.49E+04

16.48

50716

26.088

7.06E+04

300

34.02

7.09E+04

21.86

51287

32.47

7.51E+04

360

40.32

6.17E+04

26.82

59017

39.07

8.04E+04

28.63

64038 46.04

8.64E+04

390 420

47.11

6.99E+04

465

49.25

7.54E+04

480

32.3

68012

53.55

9.35E+04

37.08

73434

61.81

1.02E+05

41.8

74867

71

1.12E+05

42.82

97000

81

1.23E+05

56.22

98327

90.39

1.32E+05

70.71

120620

96.39

1.38E+05

79.37

109391

840

98.67

1.38E+05

900

99.3

1.37E+05

510

57.32

8.09E+04

540 555

62.15

6.49E+04

600

71.16

9.14E+04

645

83.02

9.37E+04

660 705

94.8

1.12E+05

720 780

100

1.26E+05

Homo-propagation rate constants are regressed to fit the conversion data. Cross-propagation Cross-propagation rate constants are calculated using the reactivity ratios. Homo-termination rate constants are regressed to fit the molecular weights. Cross-termination rate constants are are set to the square root of the product of the homo-termination rate constants. In the styrene-ethyl acrylate kinetic scheme, eleven reactions were chosen and the gel-effect was applied to the t he termination and initiation reaction. Recall that

. This results in thirty-four kinetic parameters

and twenty gel-effect parameters available for fitting. The available data is not sufficient to regress all these parameters. The following approach was used to reduce the number of parameters needed for a good fit. •

Since the batch reactor is operated at 1 atm, the effect of activation volume on the rate constant can be neglected for all the reactions. Therefore, the activation volume was set to zero for all the reactions. Note that at high pressures the effect of activation volume cannot be neglected.

•

The initiator decomposition rate constants were known. Typically these can be obtained from a good polymer handbook or from the supplier. They can also be calculated using the half-life data. (See Appendix B of the Aspen Polymers Plus User User Guide, Guide, Volume 1).

•

Chain initiation rate constants are in general faster than the propagation rate constants. Therefore these constants were set to be the same or greater than the propagation rate constants.

•

There are two homo-propagation reactions and two cross-propagation reactions in the kinetic scheme. The number of regressable parameters is then eight excluding the activation volume parameters.

•

The number of regressable propagation parameters can be reduced if the homo-propagation rate constants and/or the reactivity ratios are known. If the homo-propagation rate constants are known then reactivity ratios can be estimated. If the reactivity ratios are known homo-propagation rate constants can be estimated. In this example, reactivity ratios were given (Fehervari et al., 1981), and the homo-propagation rate constants were regressed. The cross-propagation rate constants were calculated using the following equations:

Where: STY=1 EA=2 •

Four termination reactions are considered in this scheme. Crosstermination reactions involving STY and EA segments were set to have the same rate constant. This reduces specification of the rate constants to three. If the homo-termination rate constants are known, the crosstermination rate constants can be estimated using the following equations:

In this example homo-termination rate constants were regressed using the molecular weight data.

162

•

In the kinetic scheme termination by combination was selected. It is possible that termination by disproportionation can also occur. One needs to know apriori the termination mechanism. As a general rule if polydispersity (PDI) is 1.5 termination by combination is controlling and if PDI is two termination is controlled by the disproportionation reaction.

•

At high conversion termination is diffusion controlled. This is modeled using the gel-effect option. Therefore use of low conversion data is recommended for regression of the kinetic parameters without using geleffect. High conversion data is then used to regress the gel-effect parameters.

•

Monomer conversion data was used to regress the initiator efficiency, propagation and the termination rate constants. Molecular weight data was used to regress the propagation and the termination rate constants.


The gel-effect parameters influence both the conversion and the molecular weight. •

Chain transfer reactions do not affect the conversion but affect the polymer molecular weight.

The following table summarizes the approach for fitting the kinetic rate constant parameters: Required Data Reaction

Parameter

Conversion

MWn or DPn

PDI

INIT-DEC

kd

Initiator

PROPAGATIO N

kp

Monomer

X

X

CHAT-MON

ktrm

X

X

CHAT-SOL

ktrs

X

X

CHAT-AG

ktra

X

X

TERM-DIS

ktd

Monomer

X

X

TERM-COM

ktc

Monomer

X

X

INHIBITION

kx

Monomer

X

X

CHAT-POL

ktrp

SC-BRANCH

kscb

X

LCB

SCB

Copolymer Composition

X

X X

Process Studies Input Summary The input language summary for this example is shown here: DYNAPLUS DPLUS RESULTS=ON TITLE 'Data-fit Example Using Free Radical Polymerization' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C TIME=hr VOLUME=l MASS-DENSITY='gm/cc' & PDROP='N/sqm'

&

OUT-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm & TEMPERATURE=C TIME=min VOLUME=l MASS-DENSITY='gm/cc' & PDROP='N/sqm' DEF-STREAMS CONVEN ALL RUN-CONTROL MAX-TIME=1200000.0 DESCRIPTION " Batch reactor data for styrene-ethyl acrylate

polymerization is used to regress the propagation rate constant " DATABANKS POLYMER

/ SEGMENT


/ PURE12

/ SEGMENT

/ NOASPENPCD

/ PURE12

COMPONENTS AIBN C8H8 / STY C8H8 / EA C5H8O2 / STY-SEG C8H8-R / EA-SEG C5H8O2-R-2 / POLYMER PS-1 FLOWSHEET BLOCK BATCH IN=FEED OUT=POLYMER BLOCK MIX IN=MONOMER INIT OUT=FEED PROPERTIES POLYNRTL PROP-DATA MW IN-UNITS ENG PROP-LIST MW PVAL AIBN 164.2120 POLYMERS SEGMENTS STY-SEG REPEAT / EA-SEG REPEAT POLYMERS POLYMER ATTRIBUTES POLYMER SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM SMOM

&

PROP-SET INITCONC IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' PROPNAME-LIS MOLECONC UNITS='mol/l' SUBSTREAM=MIXED & COMPS=AIBN PROP-SET POLY-MF IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' PROPNAME-LIS MASSFRAC SUBSTREAM=MIXED COMPS=POLYMER PHASE=L STREAM INIT IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C VOLUME=l & MASS-DENSITY='gm/cc' PDROP='N/sqm' SUBSTREAM MIXED TEMP=50.0 PRES=1.0 MOLE-FLOW AIBN .05710370

&

STREAM MONOMER IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=atm TEMPERATURE=C VOLUME=l & MASS-DENSITY='gm/cc' PDROP='N/sqm' SUBSTREAM MIXED TEMP=60.0 PRES=1.0 MASS-FLOW=1000.0 MOLE-FRAC STY .7620 / EA .2380

164


BLOCK MIX MIXER IN-UNITS ENG BLOCK BATCH RBATCH PARAM TYPE=T-SPEC PRINT-TIME=1.0 CYCLE-TIME=1.0 & MAX-TIME=25.0 MAX-NPOINT=27 TEMP=60.0 ERR-METHOD=DYNAMIC STOP 1 REACTOR TIME 25.0 PROP-REACTOR POLY-MF REACTIONS RXN-IDS=STY-EA EO-CONV-OPTI CALCULATOR F-1 DEFINE F PARAMETER 1 F F = 5 EXECUTE FIRST CALCULATOR K-PROP IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' DEFINE PROP11 REACT-VAR REACTION=STY-EA VARIABLE=PRPRE-EXP SENTENCE=PROPAGATION ID1=STY ID2=STY DEFINE PROP12 REACT-VAR REACTION=STY-EA VARIABLE=PRPRE-EXP SENTENCE=PROPAGATION ID1=STY ID2=EA DEFINE PROP21 REACT-VAR REACTION=STY-EA VARIABLE=PRPRE-EXP SENTENCE=PROPAGATION ID1=EA ID2=STY DEFINE PROP22 REACT-VAR REACTION=STY-EA VARIABLE=PRPRE-EXP SENTENCE=PROPAGATION ID1=EA ID2=EA F R1 = 0.717 F R2 = 0.128 F PROP12 = PROP11/R1 F PROP21 = PROP22/R2 READ-VARS PROP11 PROP22 WRITE-VARS PROP12 PROP21 CALCULATOR K-TERM IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' DEFINE TC11 REACT-VAR REACTION=STY-EA VARIABLE=TCPRE-EXP SENTENCE=TERM-COMB ID1=STY ID2=STY DEFINE TC12 REACT-VAR REACTION=STY-EA VARIABLE=TCPRE-EXP SENTENCE=TERM-COMB ID1=STY ID2=EA DEFINE TC21 REACT-VAR REACTION=STY-EA VARIABLE=TCPRE-EXP SENTENCE=TERM-COMB ID1=EA ID2=STY DEFINE TC22 REACT-VAR REACTION=STY-EA VARIABLE=TCPRE-EXP SENTENCE=TERM-COMB ID1=EA ID2=EA DEFINE F PARAMETER 1 F TC12 = F*(TC11*TC22)**0.5 F TC21 = F*(TC11*TC22)**0.5 READ-VARS TC11 TC22 WRITE-VARS TC12 TC21 CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MOLEFRAC MASSFRAC

&

& & & &

& & & &

PROPERTIES=INITCONC REACTIONS STY-EA FREE-RAD IN-UNITS SI PARAM QSSA=YES SPECIES INITIATOR=AIBN MONOMER=STY EA POLYMER=POLYMER MON-RSEG STY STY-SEG / EA EA-SEG INIT-DEC AIBN 1.8200E+15 1.2880E+08 EFFIC=.5080 CHAIN-INI STY 4500000.0 2.6000E+07 CHAIN-INI EA 3000000.0 2.2400E+07 PROPAGATION STY STY 2343800.0 2.6000E+07 PROPAGATION STY EA 3265620.0 2.6000E+07 PROPAGATION EA STY 1.4918E+07 2.2400E+07 PROPAGATION EA EA 3000000.0 2.2400E+07 CHAT-MON STY STY 117.190 2.6000E+07 CHAT-MON STY EA 163.30 2.6000E+07 CHAT-MON EA STY 746.0 2.2400E+07 CHAT-MON EA EA 95.50 2.2400E+07 TERM-COMB STY STY 1.4592E+09 7000000.0 TERM-COMB STY EA 6.6300E+10 1.4600E+07 TERM-COMB EA STY 6.6300E+10 1.4600E+07 TERM-COMB EA EA 3.0000E+11 2.2200E+07 GEL-EFFECT INIT-EFF 2 MAX-PARAMS=10 GE-PARAMS=-17.40 & .055280 17.8240 -.05090 0.0 0.0 0.0 0.0 0.0 2.0 GEL-EFFECT TERMINATION 2 MAX-PARAMS=10 GE-PARAMS=1.0 0.0 2.570 -.005050 9.560 -.01760 -3.030 .007850 0.0 2.0 REGRESSION K-PROP IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' DATA WPOLY VARY REACT-VAR REACTION=STY-EA VARIABLE=PRPRE-EXP SENTENCE=PROPAGATION ID1=STY ID2=STY LIMITS 5E4 1E7 ALGORITHM MXPASS=3000

&

& &

DATA-SET MWN IN-UNITS ENG DEFINE TIME BLOCK-VAR BLOCK=BATCH VARIABLE=VALUE & SENTENCE=STOP ID1=1 DEFINE MWN COMP-ATTR-VAR STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=POLYMER ATTRIBUTE=MWN ELEMENT=1 INPUT TIME RESULT MWN USE STD-DEV .010 5000.0 / DATA 2.0 96148.0 / DATA 4.0 & 96939.0 / DATA 6.0 98547.0 / DATA 8.0 102418.0 / & DATA 10.0 101941.0 / DATA 12.0 104354.0 / DATA 14.0 & 105066.0 / DATA 15.50 112415.0 / DATA 17.0 112159.0 / & DATA 18.50 112001.0 / DATA 20.0 114564.0 / DATA & 21.50 135065.0 / DATA 23.50 133690.0 / DATA 27.0 & 120899.0 DATA-SET WPOL-SFR IN-UNITS ENG DEFINE TIME BLOCK-VAR BLOCK=BATCH VARIABLE=VALUE & SENTENCE=STOP ID1=1 DEFINE WPOLY MASS-FRAC STREAM=POLYMER SUBSTREAM=MIXED

166

&


COMPONENT=POLYMER DEFINE SFRAC COMP-ATTR-VAR STREAM=POLYMER SUBSTREAM=MIXED COMPONENT=POLYMER ATTRIBUTE=SFRAC ELEMENT=1 INPUT TIME RESULT WPOLY SFRAC USE STD-DEV .010 .010 .010 / DATA 2.0 .05680 .7590 / & DATA 4.0 .10790 .7980 / DATA 6.0 .16090 .7660 / & DATA 8.0 .21060 .7360 / DATA 10.0 .26160 .7710 / & DATA 12.0 .37550 .7510 / DATA 14.0 .3660 .7630 / & DATA 20.0 .61440 .780 / DATA 21.50 .68660 .7870 / & DATA 23.50 .77460 .7970 / DATA 27.0 .97440 .7550

&

DATA-SET WPOLY IN-UNITS ENG DEFINE TIME BLOCK-VAR BLOCK=BATCH VARIABLE=VALUE & SENTENCE=STOP ID1=1 DEFINE WPOLY MASS-FRAC STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=POLYMER INPUT TIME RESULT WPOLY USE STD-DEV .010 .010 / DATA 2.0 .05680 / DATA 4.0 & .10790 / DATA 6.0 .16090 / DATA 8.0 .21060 / DATA & 10.0 .26160 / DATA 12.0 .37750 / DATA 14.0 .3660 / & DATA 15.50 .39360 / DATA 17.0 .45970 / DATA 18.50 & .54680 / DATA 20.0 .61440 / DATA 21.50 .68660 / & DATA 23.50 .77460 ;

Selected Simulation Results The following two figures show estimated molecular weight and monomer conversion as a function of the experimental data. As shown in these figures, a good match is obtained between the predictions and experimental data. The values of the fitted parameters are: Reaction

Parameter

Styrene homopropagation

Pre-exponential factor

EA homo-propagation homo-propagation


Styrene homotermination EA homo-termination

Estimate

Std. Dev.

Confidence Lower Limit

Internal Upper Limit


---

---

---


---

---

---

The estimated versus measured MWn is shown here:

The estimated versus measured monomer conversion is shown here:

168


The following figures show the conversion and molecular weight data comparison of the simulation results with the experimental data at 50 and 60°C respectively.

A comparison of simulation results and experimental data at 50 °C is shown here:

A comparison of simulation results and experimental data at 60 °C is shown here:

170


References Fehervari, A, Foldes-Berezsnich, T., & Tudos, F. (1981). J. (1981). J. Macromol. Sci. Chem., Chem., A16 A16,, p. 993. McManus, N. T., & Penlidis, A. (1996). A Kinetic Investigation of Styrene/Ethyl Acrylate Copolymerization. J. Copolymerization. J. Polym. Sci. Polym. Chem Chem., ., 34, 34, p. 237.

C5 Styrene Butadiene Emulsion Copolymerization Process

The styrene butadiene emulsion copolymerization process model illustrates the use of Aspen Polymers Plus to model the free-radical emulsion polymerization of styrene and butadiene in a semi-batch reactor. The model is used to examine several several process parameters parameters as a function of time: average number of radicals per particle, monomer concentration in the various phases, and monomer conversion.

About This Process In this process, the emulsion copolymerization of styrene and butadiene is carried out in a batch reactor using ammonium persulfate (APS) as the initiator, sodium lauryl sulfate (SLS) as the emulsifier and tertiary dodecyl mercaptane (TDM) as a chain transfer agent. Functionalized styrenebutadiene emulsions are used in a variety of applications such as paper coatings, carpet backings, non-wovens, etc. In addition, emulsion polymerization is the major route for the production of synthetic rubber used in the tire industries. Most styrene-butadiene rubber (SBR) latexes are manufactured in semi-batch reactors. SBR production technology is det ailed by Blackley (Blackley, 1983). In a typical semi-batch process employing in-situ seeding, the initial charge is used for the production of seed particles, with the desired particle size and particle size distribution. Usually, anionic emulsifiers and water-soluble persulfate initiators are used for particle nucleation by the micellar mechanism. When the initial mixture is heated, the radicals generated from the initiator become surface active and enter micelles to form particles. Once the particle specifications are met, monomers and other ingredients, such as chain transfer agent, stabilizers, initiators, are continuously added to the reactor, and the particles are grown to the desired final particle size.

172

C5 Styrene Butadiene Emulsion Copolymeriz Copolymerization ation Process

The latter stage of the reaction is also known as the growth stage of the reaction, and is responsible for the development of the properties of the emulsion polymer: molecular weight, composition, micro structure, etc. The growth stage is the better understood stage of the process. Therefore, this stage provides more opportunities to control the emulsion process. The adjustable process parameters include temperature and feeding strategy of monomer and other ingredients. Control of polymer composition is very often achieved by feeding the monomers in a manner such that there is no separate monomer droplet present in the reactor. Very often the productivity of the reactor is limited by its cooling capacity. Chain transfer agents are usually added to control molecular weight, and degree of branching.

Process Definition The process flowsheet consists of the batch reactor with an initial batch charge and a continuous feed for the addition of monomers and other ingredients:

This model provides the base case, which can be used to study various process variables: effect of initiator and emulsifier levels, temperature, Smith-Ewart kinetics, etc.


Name

Databank

Description

Styrene

STY

PURE12

Monomer

Butadiene

BD

PURE12

Monomer

Water

H2O

PURE12

Dispersant

Ammonia persulfate

APS

PURE12

Initiator (Mw=220.0) Select H2O

Sodium lauryl sulfate

SLS

PURE12

Emulsifier (Mw=288.0) Select H2O

Polymer

POLYMER

POLYMER

Polymer

Styrene-segment Styrene-segment

STY-SEG

SEGMENT

Repeat segment

Butadienesegment

BD-SEG

SEGMENT

Repeat segment

Tert dodecyl mercaptane

TDM

PURE12

Chain transfer agent (MW= 224, select C8H8)

Polymer Characterization

Choose emulsion polymer attributes Distribution = chain-size No. of points = 100 (upper = 100000)

Physical Properties

POLYNRTL property method with supplied binary interaction parameters

Feeds Charge Stream

CFEED

Temperature (°C)

20

20

Pressure (atm)

10

10

Styrene (kg/hr)

300

700

Butadiene Butadien e (kg/hr)

300

700

Sodium laurylsulfate (kg/hr)

30

100

Ammonium persulfate (kg/hr)

7

3

TDM (kg/hr)

30

0

Water (kg/hr)

1000

1000

Continuous Feed Time (hr)

Total (kg/hr)

0.0

0.0

1.0

0.0

1.0

1200.0

2.0

1200.0

2.0

0.0

Kinetics

EMULSION

Operating Conditions B1 Pressure (atm)

10

FLASH Option

NO

Temperature profile

174

Time (hr)

Temperature (°C)

0.0

65.0

0.5

65.0

0.5

70.0

1.0

70.0

1.0

75.0


2.0

75.0

Physical Property Models and Data The Polymer Non-Random Two Liquid activity coefficient model (POLYNRTL) is used as the physical property method. The thermophysical properties (density, heat capacity, etc.) of the monomers are obtained from the Aspen Plus pure component databank. The polymer physical properties are calculated using the van Krevelen method. Initiator concentrations are calculated for all of the phases. Note: Prior to release 12, all initiators were required to be in the aqueous phase for emulsion emulsion polymerizations. However, NRTL parameters are are now required to define the initiator APS in the aqueous phase. The NRTL binary interaction parameters are: NRTL H2O

STY

3.6260

1513.50

.360

0.0

0.0

0.0

0.0

1000.0

STY

H2O

-4.4360

2869.70

.360

0.0

0.0

0.0

0.0

1000.0

H2O

BD

3.5890

862.820

.30

0.0 0. 0

0.0

0.0

0.0

1000.0

BD

H2O

-.8520

702.170

.30

0.0

0.0

0.0

0.0

1000.0

APS

STY

0

5000

.01

0.0

0.0

0.0

0.0

1000.0

STY

APS

0

5000

.01

0.0

0.0

0.0

0.0

1000.0

APS

BD

0

5000

.01

0.0

0.0

0.0

0.0

1000.0

BD

APS

0

5000

.01

0.0

0.0

0.0

0.0

1000.0

Reactors / Kinetics There are considerable data available on the kinetics of emulsion copolymerization of styrene and butadiene. It is assumed that the primary chain transfer reaction is similar to that of a monomer. The rate constants for the kinetic scheme are obtained from Broadhead and are summarized here (Broadhead, 1984; Ponnuswamy & Hamielec, 1997): Reaction

Phase

Comp 1

Comp 2 (J/kmol)


Dispersant

Ammonium persulfate

---

1.0E16

1.402E8

Propagation

Polymer

Styrene

Styrene

2.2E7

3.2E7

Propagation

Polymer

Styrene

Butadiene

4.4E7

3.2E7

Propagation

Polymer

Butadiene

Butadiene

1.2E8

3.88E7

Propagation

Polymer

Butadiene

Styrene

8.5E7

3.88E7

Chain transfermonomer

Polymer

Styrene

Styrene

2.2E3 2.2E3

3.2E7


Polymer

Styrene

Butadiene

4.4E3

3.2E7

Reaction

Phase

Comp 1

Comp 2 (J/kmol)


Polymer

Butadiene

Butadiene

1.2E4

2.24E6


Polymer

Butadiene

Styrene

8.5E3

3.88E7

Chat-agent

Polymer

Styrene

TDM

2.83E5

2.68E7

Chat-agent

Polymer

Butadiene

TDM

8.5E5

3.88E7


Polymer

Styrene

Styrene

1.3E9 1.3E9

9.9E6


Polymer

Styrene

Butadiene

1.3E9

9.9E6


Polymer

Butadiene

Butadiene

1.3E9

9.9E6


Polymer

Butadiene

Styrene

1.3E9

9.9E6

In addition to the free-radical reaction rate constants, the following rate constants were used for the radical exchange events: Reaction

(J/kmol)

Absorption into particle

1.0E-7

0.0

Absorption into micelles

1.0E-7

0.0

Desorption from particle

0.0

0.0

Other parameters affecting the kinetics are the emulsifier parameters and the monomer partitioning. These are listed here: CMC kmol / m 3

Area m3 / kmole

Emulsifier parameters

0.009

5.0E6

Monomer partitioning (mass)

Styrene

.70 homosaturation in polymer

Butadiene


TDM


Process Studies The model was used to examine the following process parameters as a function of time through user profiles:

176

Glass transition temperature of the polymer

(K)

Average number of radicals per particle

---

Percent of soap coverage of particles

%

Volume of the monomer phase

(m3)

Concentration of monomer 1 in monomer phase

(Kmol/ m3)


Concentration of monomer 2 in monomer phase

(Kmol/ m3)

Volume of the aqueous phase

(m3)

Concentration of the monomer 1 in aqueous phase

(Kmol / m3)

Concentration of the monomer 2 in aqueous phase

(Kmol / m3)

Volume of the polymer phase

(m3)

Concentration of the monomer 1 in polymer phase

(Kmol / m3)

Concentration of the monomer 2 in polymer phase

(Kmol / m3)

Total mass conversion of monomer to polymer

---

Input Summary The input language summary for this example is shown here: TITLE 'EMULSION COPOLYMERIZATION OF STYRENE AND BUTADIENE' IN-UNITS SI MASS-FLOW='kg/hr' PRESSURE=bar TEMPERATURE=C TIME=hr PDROP='N/sqm'

&

DEF-STREAMS CONVEN ALL SYS-OPTIONS TRACE=YES DESCRIPTION " THIS EXAMPLE ILLUSTRATES THE USE OF ASPEN POLYMERS PLUS TO MODEL THE COPOLYMERIZATION OF STYRENE AND BUTADIENE IN A BATCH REACTOR. " DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS H2O H2O / STY C8H8 / BD C4H6-4 / POLYMER POLYMER / STY-SEG C8H8-R / BD-SEG C4H6-R-1 / APS H2O / SLS H2O / TDM C8H8 FLOWSHEET BLOCK REACTOR IN=CHARGE CONTFEED OUT=PRODUCT PROPERTIES POLYNRTL

USER-PROPS GMRENA 1 2 1 / GMRENB 1 2 1 / GMRENC 1 2 1 / GMREND 1 2 1

&

PROP-DATA MW IN-UNITS SI MASS-FLOW='kg/hr' PRESSURE=bar TEMPERATURE=C TIME=hr PDROP='N/sqm' PROP-LIST MW PVAL APS 228.0 PVAL SLS 288.0 PVAL TDM 202.40 PROP-DATA TGVK IN-UNITS SI MASS-FLOW='kg/hr' PRESSURE=bar TEMPERATURE=C TIME=hr PDROP='N/sqm' PROP-LIST TGVK PVAL STY-SEG 100.0 PVAL BD-SEG -54.0

&

&

PROP-DATA NRTL-1 IN-UNITS SI PROP-LIST NRTL BPVAL H2O STY 3.6260 1513.50 .360 0.0 0.0 0.0 0.0 & 1000.0 BPVAL STY H2O -4.4360 2869.70 .360 0.0 0.0 0.0 0.0 & 1000.0 BPVAL H2O BD 3.5890 862.820 .30 0.0 0.0 0.0 0.0 1000.0 BPVAL BD H2O -.8520 702.170 .30 0.0 0.0 0.0 0.0 1000.0 BPVAL APS STY 0 5000 .01 0.0 0.0 0.0 0.0 1000.000 BPVAL STY APS 0.0 5000 .01 0.0 0.0 0.0 0.0 1000.000 BPVAL APS BD 0 5000 .01 0.0 0.0 0.0 0.0 1000.000 BPVAL BD APS 0.0 5000 .01 0.0 0.0 0.0 0.0 1000.000 POLYMERS SEGMENTS STY-SEG REPEAT / BD-SEG REPEAT POLYMERS POLYMER ATTRIBUTES POLYMER SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM & FMOM SMOM PSDZMOM PSDFMOM DIAV DISTRIBUTION POLYMER CHAIN-SIZE CLD NPOINTS=100 FUNCLOG=NO UPPER=100000.0

&

PROP-SET PS-1 MASSFRAC SUBSTREAM=MIXED COMPS=POLYMER PHASE=L STREAM CHARGE SUBSTREAM MIXED TEMP=20.0 PRES=10.0 MASS-FLOW H2O 1000.0 / STY 300.0 / BD 300.0 / POLYMER 0.0 / APS 7.0 / SLS 30.0 / TDM 30.0 STREAM CONTFEED SUBSTREAM MIXED TEMP=20.0 PRES=10.0 MASS-FLOW H2O 1000.0 / STY 700.0 / BD 700.0 / POLYMER 0.0 / APS 3.0 / SLS 100.0

&

&

BLOCK REACTOR RBATCH USER-VECS NUSER-PROF=13 USERPROF ELEMENT=1 LABEL="TGAVG" UNIT-LABEL="DEG K" USERPROF ELEMENT=2 LABEL="NBAR" UNIT-LABEL="#/PARTICLE" USERPROF ELEMENT=3 LABEL="S-COVER" UNIT-LABEL="%"

178


USERPROF ELEMENT=4 LABEL="M-VOL" UNIT-LABEL="M**3" USERPROF ELEMENT=5 LABEL="CM-1" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=6 LABEL="CM-2" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=7 LABEL="AQ-VOL" UNIT-LABEL="M**3" USERPROF ELEMENT=8 LABEL="CAQ-1" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=9 LABEL="CAQ-2" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=10 LABEL="POL-VOL" UNIT-LABEL="M**3" USERPROF ELEMENT=11 LABEL="CPOL-1" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=12 LABEL="CPOL-2" UNIT-LABEL="KMOL/M**3" USERPROF ELEMENT=13 LABEL="CONVER" UNIT-LABEL="MASS FRAC" PARAM TYPE=T-PROFILE PRINT-TIME=.20 CYCLE-TIME=1.0 & MAX-TIME=10.0 MAX-NPOINT=100 PRES=10.0 NPHASE=1 & HINIT=.000010 FLASH=NO INTEG-PARAMS MAXSTEP=.008333333 T-PROF 0.0 65.0 / .50 65.0 / .50 70.0 / 1.0 70.0 / & 1.0 75.0 / 2.0 75.0 STOP 1 REACTOR TIME 10.0 PROP-REACTOR PS-1 BLOCK-OPTION STREAM-LEVEL=4 TERM-LEVEL=7 REACTIONS RXN-IDS=EMLRXN FEED-PROF SID=CONTFEED TIME=0.0 1.0 1.0 2.0 2.0 FLOW=0.0 & 0.0 1200.0 1200.0 0.0 EO-CONV-OPTI CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MOLEFRAC MASSFRAC REACTIONS EMLRXN EMULSION PARAM KBASIS=MONOMER QSSA=YES SPECIES INITIATOR=APS MONOMER=STY BD CHAINTAG=TDM EMULSIFIER=SLS DISPERSANT=H2O POLYMER=POLYMER MON-RSEG STY STY-SEG / BD BD-SEG INIT-DEC DISPERSANT APS 1.0000E+16 1.4020E+08 0.0 EFFIC=.80 NRADS=2 PROPAGATION POLYMER STY STY 2.2000E+07 3.2000E+07 PROPAGATION POLYMER STY BD 4.4000E+07 3.2000E+07 PROPAGATION POLYMER BD BD 1.2000E+08 3.8800E+07 PROPAGATION POLYMER BD STY 8.5000E+07 3.8800E+07 CHAT-MON POLYMER STY STY 2200.0 3.2000E+07 CHAT-MON POLYMER STY BD 4400.0 3.2000E+07 CHAT-MON POLYMER BD BD 12000.0 3.8800E+07 CHAT-MON POLYMER BD STY 8500.0 3.8800E+07 CHAT-AGENT POLYMER STY TDM 283000.0 2.6800E+07 CHAT-AGENT POLYMER BD TDM 850000.0 3.8800E+07 TERM-COMB POLYMER STY STY 1.3000E+09 9900000.0 TERM-COMB POLYMER STY BD 1.3000E+09 9900000.0 TERM-COMB POLYMER BD BD 1.3000E+09 9900000.0 TERM-COMB POLYMER BD STY 1.3000E+09 9900000.0 ABS-MIC 1.0000E-07 0.0 ABS-PART 1.0000E-07 0.0 DES-PART 0.0 0.0 EMUL-PARAMS SLS .0090 5000000.0 SPLIT-PM STY .70 SPLIT-PM BD .50

& &

SPLIT-PM TDM .80

Selected Simulation Results The figures that follow show selected results for emulsion polymerization of styrene and butadiene in a semi-batch reactor. The nucleation and growth of emulsion polymer particles in the reactor is shown here: 1 2 e 4 . ) t 1 n 1 e 2 e m . o 2 1 m h 1 t 0 2 e 1 D S 0 P ( 2 s e e 8 l c i t r 0 a 2 e P f 6 o r 0 e b 2 e 4 m u N 0 2 e 2

3 4 m . ) 1 t n e m . o 2 1 m t s 1 1 D S P ( r 8 e . 0 m y l o P 6 . n 0 e l l o w s 4 . n 0 U e m 2 . u 0 l o V

0

0

4 1 . 0 n 2 o . r 1 c 0 i m , r . e 1 t e 0 m a 8 i 0 D . e 0 l c i t r 6 a 0 . P 0 e g a r 4 e 0 . v 0 A 2 0 . 0

0

1

2

3

4

5 6 Time, hr

7

8

9

10 10

As shown, the number of particles formed early remains constant throughout the reaction. In this figure, first moment, which is the total volume of the unswollen polymer particles, increases throughout the polymerization as expected. The figure also shows that the average diameter of the unswollen particle increases as expected. The mass of monomers and polymer in the reactor is shown here:

180


0 5 2 1 0 0 0 1

Styrene, Kg

g K , y 0 5 r o 7 t n e v n 0 I s 0 s 5 a M

Polymer, Kg

Butadiene, Kg

0 5 2

0

1

2

3

4

5 6 Time, hr

7

8

9

10 10

Although the flow rates of styrene and butadiene are equal, the figure shows that butadiene reacts faster than styrene due to its higher reactivity. The volume of the monomer, polymer, and aqueous phases in the reactor is shown here: 6 . 1 2 . 3 1 m , e m u 8 l . o 0 V e s a h P 4 . 0

0

Monomer Aqueous Polymer

1

2

3

4

5 Time, hr

6

7

8

9

10 10

As shown, the monomer droplets are completely depleted after 2.5 hours. As expected, the volume of the swollen polymer phase decreases after the depletion of the monomer droplets. The number average and weight average degree of polymerization and the polydispersity is shown here:

0 0 0 6 0 0 0 n 5 o i t a 0 0 z i r 0 e 4 m y 0 l o 0 0 P f 3 o e 0 e 0 r g 0 e 2 D 0 0 0 1 0

4 DPN DPW

5 . 3

PDI

x e d n 3 I y t i s r e p s i 5 . d 2 y l o P 2

0

1

2

3

4

5 6 Time, hr

7

8

9

10 10

The composition of the polymer is shown here: 8 . 0 7 . 0 6 . C 0 A R F 5 . S , 0 n o 4 . i t c 0 a r F 3 . e 0 l o 2 . M 0 1 . 0 0

Styrene Butadiene 1

2

3

4

5 6 Time, hr

7

8

9

10 10

As expected, the composition of the reactive butadiene monomer in the polymer is higher in comparison to styrene. The chain length distribution is shown here:

182


2 0 0 0 . 0

DPN DPW PDI Area

5 1 0 n 0 o i 0 . t c 0 a r F 1 t 0 h 0 g 0 i . e 0 W

= = = =

Distrib 1155.97 3926.32 3.3965 1.0021

Moments 968.44 3242.01 3.3476

5 e 5

1

100 10000 Degree of polymerization

1e6

References Blackley, D. C. (1983). Synthetic Rubbers: Their Chemistry and Technology. New York: Applied Science Publishers. Broadhead, T. O. (1984). Dynamic Modeling of the Emulsion Copolymerization of Styrene/Butadiene. Styrene/Butadiene. M. E. Thesis, McMaster Univ. Ponnuswamy, S. R., & Hamielec, A. E. (1997). Emulsion Polymerization Theory and Practice. Practice . Lecture Notes for Intensive Short Course on Polymer Reaction Engineering, Burlington, Ontario Canada.

C6 Styrene Butadiene Ionic Polymerization Processes

The styrene butadiene rubber (SBR) ionic solution process model illustrates the use of Aspen Polymers Plus to model an anionic polymerization of styrene and butadiene. The model describes the production of tapered block copolymer using a batch reactor.

About This Process Block copolymers of styrene and butadiene are formed by living anionic polymerization initiated by alkyllithiums. These monomers can be polymerized over a wide range of useful temperatures from room temperature to elevated temperatures (100°C). Adding alkyllithium initiator to styrene and butadiene in hydrocarbon solution produces a copolymer containing long polybutadiene and polystyrene blocks (tapered block copolymers). Although styrene homo-polymerizes more rapidly than butadiene with alkyllithiums in hydrocarbon solution, it does not polymerize first in the mixture. Butadiene is incorporated with a small amount of styrene i nto the copolymer first, and only then is the residual styrene free to form blocks by homopolymerization onto the polybutadienyllithium. Because of the stability of “living” nature of the allylic lithium end group, butadiene-styrene copolymers of widely different structures and properties can be prepared. The SBR copolymer can either be a random, tapered block, or di/tri-block copolymer. The solvent influences the reactivity ratios of styrene and butadiene. The solvents change the overall rates while the general shape of the batch polymerization curves remains the same. The reactivity ratios (

) are a strong function of the solvent. For styrene (s)

and butadiene (b) monomers in cyclohexane solvent, the reactivity ratio, r b, is about 50 times larger than rs, and these rate constants determine what type of copolymer will be formed. If a mixture of styrene and butadiene is polymerized using alkyllithium initiator and cyclohexane solvent with the above kinetics in a batch reactor,

184

C6 Styrene Butadiene Ionic Polymerizati Polymerization on Processes

tapered block copolymer is produced. One segment would be a butadienestyrene copolymer and the other would be a polystyrene block with an overall B/S-S structure. If the same mixture is polymerized in a semi-batch reactor with sequential addition and polymerization of styrene, butadiene and styrene again results in a tri-block copolymer. A continuous reactor would produce a random copolymer (when

).

The kinetics identified using the model may be used to perform studies using all three (batch, semi-batch, and continuous) operations.

Process Definition This application demonstrates production of tapered block SBR polymerization in a continuous reactor. A schematic of a batch reactor using the ionic kinetics is shown here:

The following components are present in the simulation flowsheet: BULI-3

Associated BuLi initiator as a trimer

BULI-1

Dissociated BuLi initiator which initiates the chain

STYRENE

Styrene monomer

STY-SEG

Styrene segment

BUTDIENE

Butadiene monomer

BUT-SEG

Bbutadiene segment

HEXANE

Cyclohexane as solvent

SBR

Polymer

Usually there is greater control over the polymer properties i n batch/semibatch reactors compared to a CSTR. In this example, the effect of varying feed conditions is studied on the conversion profile. This simulation is performed in a batch reactor using Aspen Polymers Plus. Various feed policies can be studied in the batch reactor to get the desired SBR properties.

Process Conditions The batch reactor is simulated for an hour with the following components mass flows in the feed with one-hour reactor cycle time: Associated Initiator (Butyl Lithium)

0.13 kg/hr

Styrene Monomer

50 kg/hr

Butadiene Monomer

50 kg/hr

Cyclohexane

1000 kg/hr

Even though there is more reactive styrene present in the feed, butadiene is first consumed during the polymerization. After butadiene is consumed, the reaction rate jumps as soon as styrene homopolymerization is initiated. This behavior is governed by cross propagation reactions as discussed earlier. The key outputs predicted by the model are: Total amount of polymer formed

100 kg/hr

Mole fraction of styrene in final polymer

0.341

DPn of final polymer

1281

PDI of polymer out of CSTR

1.06

Fraction of growing polymer that is growing

0.146

Fraction of associated polymer

0.853

DPn of associated polymer

1382

Styrene to butadiene molar ratio is approximately 1:2 in the above mixture. The batch reactor is simulated for an hour.

Kinetics A comprehensive kinetic scheme for ionic copolymerization of any number of monomers has been built into Aspen Polymers Plus. The block, tapered-block, and random SBR can be modeled using this scheme. The built in kinetics can also handle the presence of multiple propagating species (for example: freeions, ion pairs, and dormant esters). The polymerization kinetic scheme includes a subset of the reactions available in the Aspen Polymers Plus ionic kinetic model:

186

Reaction Type

Site ID†

Reacting Species

Description of Reaction

INIT-DISSOC

1

BULI-3 BULI-1

Initiator dissociation (association number=3) to form active species BULI-1 (dissociated butylLithium)

CHAIN-INI-2

1

BULI-1

Chain initiation with styrene monomer

CHAIN-INI-2

1

BULI-1

STYRENE

Chain initiation with butadiene


Reaction Type

Site ID†

Reacting Species

Description of Reaction

BUTDIENE

monomer

PROPAGATION

1

BUT-SEG BUTDIENE

Propagation of butadiene active segment with butadiene monomer

PROPAGATION

1

BUT-SEG STYRENE

Propagation of butadiene active segment with styrene monomer

PROPAGATION

1

STY-SEG BUTDIENE

Propagation of styrene active segment with butadiene monomer

PROPAGATION

1

STY-SEG STYRENE

Propagation of styrene active segment with styrene monomer

ASSOCIATION

1

STY-SEG

Dimeric association of growing polymer molecules with styrene active segment

ASSOCIATION

1

BUT-SEG

Dimeric association of growing polymer molecules with butadiene active segment

†

Site ID represents the type of active active species (a value value of 1 assumes assumes only ion-pair propagates).

This example illustrates styrene copolymerization with butadiene in cyclohexane solvent. The ionic kinetic scheme consists of the three basic polymerization reaction steps: formation of active species, chain initiation, and propagation. The chain transfer and termination reactions can also be modeled with the ionic kinetic scheme.

Process Studies Input Summary An input language summary for this example is shown here: TITLE 'SBR (tapered-block) Solution Polymerization' IN-UNITS MET FLOW='lb/hr' MASS-FLOW='lb/hr' PRESSURE=psig TEMPERATURE=F DELTA-T=F PDROP=psi OUT-UNITS MET DEF-STREAMS CONVEN ALL DESCRIPTION " This example demonstrates tapered block SBR made by charging the ingredients in a batch reactor using the Ionic kinetic reaction scheme. "

&

DATABANKS POLYMER

/ SEGMENT


/ PURE93

/ SEGMENT

/ NOASPENPCD

/ PURE93

COMPONENTS BULI-6 C24H38O4-D1 / BULI-1 C4H5N-1 / STYRENE C8H8 / STY-SEG C8H8-R / BUTDIENE C4H6-4 / BUT-SEG C4H6-R-1 / HEXANE C6H10-2 / SBR SBR FLOWSHEET BLOCK BATCH IN=FEED OUT=PROD PROPERTIES POLYNRTL USER-PROPS GMRENA 1 2 1 / GMRENB 1 2 1 / GMRENC 1 2 1 / GMREND 1 2 1

&

PROP-DATA MW IN-UNITS MET PROP-LIST MW PVAL BULI-6 384 PVAL BULI-1 64 POLYMERS PARAM NSITES=1 SITCOM=INITIATOR SEGMENTS STY-SEG REPEAT / BUT-SEG REPEAT INITIATOR BULI-1 POLYMERS SBR ATTRIBUTES SBR SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM & FMOM SMOM LEFLOW LSFLOW LSFRAC LDPN LSMOM LPFRAC & SSFRAC SSFLOW SDPN SDPW SPDI SMWN SMWW SZMOM SSMOM & SPFRAC LSSFLOW LSSFRAC LSEFLOW LSEFRAC LSDPN LSSMOM & LSPFRAC ASEFLOW ASSFLOW ASSMOM ASDPN ADPN ASPDI APDI & ASFLOW ASPFRAC APFRAC DSEFLOW DSSFLOW DSSMOM ATTRIBUTES BULI-1 P0FLOW PT0FLOW CIONFLOW PROP-SET BU-LIC MOLECONC UNITS='mol/l' SUBSTREAM=MIXED COMPS=BULI-6 PHASE=L

&

PROP-SET BUTC MOLECONC UNITS='mol/l' SUBSTREAM=MIXED COMPS=BUTDIENE PHASE=L

&

PROP-SET STYC MOLECONC UNITS='mol/l' SUBSTREAM=MIXED COMPS=STYRENE PHASE=L

&

STREAM FEED IN-UNITS MET SUBSTREAM MIXED TEMP=50. PRES=1. MASS-FLOW BULI-6 0.13 / BULI-1 0. / STYRENE 50. / BUTDIENE 50. / HEXANE 1000. / SBR 0.

&

BLOCK BATCH RBATCH

188


PARAM TYPE=T-SPEC PRINT-TIME=10. CYCLE-TIME=1.
MAX-TIME=7.
MAX-NPOINT=44 PRES=10. & TEMP=50. NPHASE=1 PHASE=L FLASH=YES STOP 1 REACTOR TIME 7. BLOCK-OPTION SIM-LEVEL=4 TERM-LEVEL=10 FREE-WATER=NO REACTIONS RXN-IDS=R-ION

&

EO-CONV-OPTI STREAM-REPOR MOLEFLOW MASSFLOW MOLEFRAC PROPERTIES=BU-LIC BUTC STYC REACTIONS R-ION IONIC IN-UNITS MET SPECIES INIT=BULI-1 ASSO-INI=BULI-6 POLYMER=SBR MON-RSEG STYRENE STY-SEG / BUTDIENE BUT-SEG INIT-DISSOC BULI-6 BULI-1 0.001 0. 2E+026 0. ASSO-NO=6 CHAIN-INI-2 1 BULI-1 STYRENE 0.45 0. CHAIN-INI-2 1 BULI-1 BUTDIENE 0.8 0. PROPAGATION 1 STY-SEG STYRENE 5. 0. PROPAGATION 1 STY-SEG BUTDIENE 200. 0. PROPAGATION 1 BUT-SEG STYRENE 0.16556 0. PROPAGATION 1 BUT-SEG BUTDIENE 2.5 0. ASSOCIATION 1 STY-SEG 1000. 0. 0.01 0. ASSOCIATION 1 BUT-SEG 1000. 0. 0.01 0.

&

REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50. REF-TEMP=50.

Selected Simulation Results The rate of consumption of monomers and formation of SBR polymer is shown here: 0 5 5 4 0 4

Block BATCH (RBATCH) Profiles Composition 0 0 1

0 8

Accumulated mass MIXED MIXED STYRENE STYRENE

5 3

Accumulated mass MIXED MIXED BUTDIENE BUTDIENE Accumulated mass MIXED MIXED SBR

0 3 g k S 5 2 S A M 0 2

0 6 g k S S A M 0 4

5 1 0 1

0 2

5

0

0

0.5

1

1.5

2

2.5

3

3.5 Time hr

4

4.5

5

5.5

6

6.5

7

The figure shows the mass of monomers and polymer in the batch reactor. The consumption of styrene increases only after most of the butadiene monomer is incorporated into the polymer. The kick in polymerization takes place after most of the butadiene i s depleted and styrene homopolymerization begins. The copolymer composition during polymerization is shown here: Block BATCH (RBATCH) Profiles Component Attr.

1 5 9 . 0 9 . 0 5 8 . 0 8 . 0 5 7 . 0 7 . 0 5 6 . 0 6 . 0 5 5 . 0 5 . 0 5 4 . 0 4 . 0 5 3 . 0 3 . 0 5 2 . 0 2 . 0 5 1 . 0 1 . 0 5 0 . 0

0

Component attribute MIXED #0 SBR SFRAC STY-SEG Component attribute MIXED #1 SBR SFRAC BUT-SEG

0.5

1

1.5

2

2.5

3

3.5 Time MIXED hr

4

4.5

5

5.5

6

6.5

The figure shows the cumulative segment fraction of monomer in the polymer as a function of time. As shown, during the first phase of the polymerization, only about 10% of styrene is incorporate in the polymer. The final molar composition of styrene in the polymer is 34%. The degree of polymerization for live (LDPN), composite (DPN), and associated (ADPN) is shown here:

190


7

0 0 4 1 0 0 3 1 0 0 2 1 0 0 1 1 0 0 0 1 0 0 9

Block BATCH (RBATCH) Profiles Component Attr.

Component attribute MIXED #50 SBR ADPN ADPN Component attribute MIXED #4 SBR DPN DPN Component attribute MIXED #18 SBR LDPN LDPN

0 0 8 0 0 7 0 0 6 0 0 5 0 0 4 0 0 3 0 0 2 0 0 1 1

6

11

16

21

26

31

36

41

NPOINT

The degree of polymerization of associated polymer (ADPN) is twice the DPN of live polymer (LDPN) for a dimeric polymer association reaction. The SBR produced by ionic polymerization has control over the amount of cis, trans, and vinyl configuration in the polymer. This configuration is usually a function of temperature. The amount of cis, trans, and vinyl polymer formed is also possible to track in Aspen Polymers Plus using user kinetics subroutines. Other user subroutines (for example, viscosity correlating to fraction of aggregate polymer and weight averages) may also be used to calculate and track product specific non-molecular properties.

46

C7 High-Density Polyethylene High Temperature Solution Process

The HDPE high temperature solution process model illustrates the use of Aspen Polymers Plus to model a Ziegler-Natta solution polymerization of ethylene. The model is used to study the effect of feed flow rate on conversion and polymer properties, and to study the effect of hydrogen concentration on melt index and polydispersity index.

About This Process Polyethylene is the largest synthetic commodity polymer. It is widely used throughout the world due to its versatile physical and chemical properties. The current worldwide capacity for polyethylene is over 30 million tons and the average annual rate of capacity increase is 5-8%. The commercial production of polyethylene is done in continuous processes, gas-phase processes, slurry processes, or solution processes using highly active ZieglerNatta catalysts such as titanium supported catalysts. Aspen Polymers Plus has been used to model the high temperature solution process for polyethylene using a Ziegler-Natta catalyst. Ziegler-Natta catalysts are multi-site catalysts containing different site types, with each type having different reactivities. For this reason, each site type produces a polymer with distinct molecular weight. As a result, the composite polymer has a broad molecular weight distribution. The Ziegler-Natta model in Aspen Polymers Plus takes into account the important reactions found in this chemistry, including site activation, chain initiation, chain propagation, chain transfer, site deactivation, site inhibition, branching reactions, etc. The model is quite flexible and can be configured for homopolymerization or copolymerization with any number of monomers. Users can also specify any number of site types for the catalyst. The model predicts the various polymer properties, such as molecular weight,

192

C7 High-Density Polyethylene High Tempera Temperature ture Solution Process

polydispersity index, melt index, and copolymer composition, and returns this information for the polymer produced at each catalyst site.

Process Definition In this example, the solution polymerization of ethylene is carried out at 160°C using n-hexane as solvent. Hydrogen is used as a chain transfer agent to control molecular weight. The flowsheet consists of two reactors and a flash unit as shown:

The first reactor produces a high molecular weight polymer while the second produces a low molecular weight polymer. Solvent, unreacted monomer, and hydrogen are removed from the product in a flash tank. An intermediate feed stream going to the second reactor is used to set the concentration of hydrogen in that reactor to be several times higher than in the first reactor. A total of four site types are used for the catalyst. Two sites are considered to be active in the first reactor and all four sites are active in the second reactor.


Name

Databank

Description

Ethylene

C2H4

PURE12

Monomer

Hydrogen

H2

PURE12


n-Hexane

HEXANE

PURE12

Solvent

Catalyst

TICl4

PURE12

Catalyst

Cocatalyst

TEA

PURE12

Cocatalyst

HDPE

HDPE

POLYMER

Polymer

C2H4-R

SEGMENT

Ethylene segment

Physical Properties

POLYPCSF property method with supplied parameters for catalyst and cocatalyst (PCSFTM=20)

Feeds

Feed

R1FEED

FEED2

Composition (% by weight)

Ethylene (E2)

10.0

20.0

Hydrogen (H2)

5.0E-4

0.02

Condition

Hexane

89.975

79.95

Catalyst (TICl4)*

0.01

0.01

Cocatalyst (TEA)

0.015

0.015

Temperature

70°C

70°C

Pressure

200 atm

200 atm

Phase

Liquid

Liquid

60,000 kg/hr

10,000 kg/hr

Mass Flow Kinetics

ZIEGLER-NAT model


Block

Temp ( C)

Pres (atm)

Size

CSTR-1

160

200

60 m3

CSTR-2

160

200

60 m3

FLASH

160

10

---

* Mole fraction of potential site site fraction is one.

Reactors / Kinetics The set of reactions included from the built-in kinetics for this model are: Description

Reaction

Site activation by cocatalyst Spontaneous site activation Chain initiation Propagation Chain transfer to hydrogen Chain transfer to monomer Spontaneous chain transfer Spontaneous site deactivation

Process Studies In order to determine the effect of feed flowrate on conversion and polymer properties, and the effect of hydrogen concentration on melt index and polydispersity index, a sensitivity study is carried out. Melt index is calculated in a user supplied subroutine (Xie et al., 1994) and is chosen as one of the sampled parameters in a SENSITIVITY block. Other sampled parameters include the polymer properties, the component fractions used to determine conversion, and the flowrates.

194


Input Summary An input language summary for this example is shown here: ;This application example requires a user FORTRAN subroutine USRPRP.F ;Please copy USRPRP.F from the Application example directory and ;compile it in your local working directory. The subroutine provides ;the correlations for melt viscosity, IV and zero shear viscosity. If ;you change the component names, property name or the subroutine name ;you must update the names in the subroutine. ; ;If you don't have a compiler you can copy USERFORT.DLL and ;USERFORT.DLOPT from the Application folder to your working directory, ;enter USERFORT.DLOPT in the Run/Settings/Engine Files/Linker Options ;box and run the simulation. DYNAPLUS DPLUS RESULTS=ON TITLE 'Ziegler-Natta Solution Polymerization of Ethylene' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C PDROP='N/sqm'

&

DEF-STREAMS CONVEN ALL DIAGNOSTICS TERMINAL SIM-LEVEL=4 CONV-LEVEL=4 COST-LEVEL=4 PROP-LEVEL=4 ECON-LEVEL=4 STREAM-LEVEL=4 SYS-LEVEL=4

&

SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=10000.0 DESCRIPTION "Solution polymerization of ethylene. This file requires user FORTRAN USRPRP to calculate polymer properties." DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS TICL4 TICL4 / TEA C6H15AL / C2H4 C2H4 / H2 H2 / HEXANE C6H14-1 / HDPE HDPE / C2H4-R C2H4-R FLOWSHEET BLOCK CSTR-1 IN=R1FEED OUT=R1PROD BLOCK CSTR-2 IN=R1PROD FEED2 OUT=R2PROD BLOCK FLASH IN=R2PROD OUT=RECYCLE POLYMER ; ; THE PROPERTY CALCULATION METHOD (OPTION SET) SPECIFICATION FOLLOWS ;

PROPERTIES POLYPCSF PROP-DATA PCSAFT IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=atm TEMPERATURE=C PDROP='N/sqm' PROP-LIST PCSFTM PVAL TICL4 20 PVAL TEA 20

&

POLYMERS PARAM NSITES=4 SEGMENTS C2H4-R REPEAT CATALYST TICL4 .00010 POLYMERS HDPE ATTRIBUTES HDPE SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM & FMOM SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW & LEFRAC LPFRAC SSFRAC SSFLOW SDPN SDPW SPDI SMWN SMWW SZMOM SFMOM SSMOM SPFRAC LSDPN LSZMOM LSFMOM LSSFLOW LSSFRAC LSEFLOW LSEFRAC LSPFRAC ATTRIBUTES TICL4 CPSFLOW CPSFRAC CVSFLOW CVSFRAC CDSFLOW CDSFRAC DISTRIBUTION HDPE CHAIN-SIZE CLD NPOINTS=100 FUNCLOG=YES UPPER=100000.

& & & &

USER-PROPERT DENS SUBROUTINE=USRPRP UNIT-TYPE=DENSITY USER-PROPERT IV SUBROUTINE=USRPRP USER-PROPERT MI-K SUBROUTINE=USRPRP USER-PROPERT MI-S SUBROUTINE=USRPRP USER-PROPERT ZVIS SUBROUTINE=USRPRP UNIT-TYPE=VISCOSITY PROP-SET DENS DENS SUBSTREAM=MIXED PROP-SET IV IV SUBSTREAM=MIXED PROP-SET MI-KAR MI-K SUBSTREAM=MIXED PROP-SET MI-SIN MI-S SUBSTREAM=MIXED PROP-SET ZVIS ZVIS SUBSTREAM=MIXED STREAM FEED2 SUBSTREAM MIXED TEMP=70.0 PRES=200.0 MASS-FLOW=10000.0 & NPHASE=1 PHASE=L MASS-FRAC TICL4 .00010 / TEA .000150 / C2H4 .20 / H2 & .00020 / HEXANE 0.79955 COMP-ATTR TICL4 CPSFLOW ( 0.0 ) COMP-ATTR TICL4 CPSFRAC ( 1.0 ) COMP-ATTR TICL4 CVSFLOW ( 0.0 0. 0. 0. ) COMP-ATTR TICL4 CVSFRAC ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CDSFLOW ( 0.0 ) COMP-ATTR TICL4 CDSFRAC ( 0.0 ) STREAM R1FEED

196


SUBSTREAM MIXED TEMP=70.0 PRES=200.0 MASS-FLOW=60000.0 & NPHASE=1 PHASE=L MASS-FRAC TICL4 .00010 / TEA .000150 / C2H4 .10 / H2 & 5.0000E-06 / HEXANE 0.899745 COMP-ATTR TICL4 CPSFLOW ( 0.0 ) COMP-ATTR TICL4 CPSFRAC ( 1.0 ) COMP-ATTR TICL4 CVSFLOW ( 0.0 0. 0. 0. ) COMP-ATTR TICL4 CVSFRAC ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CDSFLOW ( 0.0 ) COMP-ATTR TICL4 CDSFRAC ( 0.0 ) BLOCK FLASH FLASH2 PARAM TEMP=160.0 PRES=10.0 BLOCK CSTR-1 RCSTR PARAM VOL=60.0 TEMP=160.0 PRES=200.0 NPHASE=1 PHASE=L MB-MAXIT=50 MB-TOL=.00010 MASS-FLOW MIXED C2H4 2500. MASS-FLOW MIXED HDPE 3500. COMP-ATTR MIXED TICL4 CPSFLOW ( .000010 ) COMP-ATTR MIXED TICL4 CDSFLOW ( 3.9581E-06 ) CONVERGENCE SOLVER=NEWTON STAB-STRAT=LINE-SEARCH BLOCK-OPTION TERM-LEVEL=7 RESTART=NO REACTIONS RXN-IDS=ZN-R1 BLOCK CSTR-2 RCSTR PARAM VOL=60.0 TEMP=160.0 PRES=200.0 NPHASE=1 PHASE=L MB-MAXIT=50 MB-TOL=.00010 MASS-FLOW MIXED C2H4 2100. MASS-FLOW MIXED HDPE 5800. COMP-ATTR MIXED TICL4 CPSFLOW ( .000010 ) COMP-ATTR MIXED TICL4 CDSFLOW ( 3.9581E-06 ) CONVERGENCE SOLVER=NEWTON STAB-STRAT=LINE-SEARCH BLOCK-OPTION TERM-LEVEL=7 RESTART=NO REACTIONS RXN-IDS=ZN-R2

&

&

EO-CONV-OPTI SENSITIVITY RTIME PARAM BASE-CASE=LAST DEFINE RHDPE2 MASS-FLOW STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=HDPE DEFINE RMW2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWW ELEMENT=1 DEFINE RMN2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWN ELEMENT=1 DEFINE RPDI2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=PDI ELEMENT=1 DEFINE RE22 MASS-FLOW STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=C2H4 DEFINE RHDPE1 MASS-FLOW STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=HDPE DEFINE RMW1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWW ELEMENT=1 DEFINE RMN1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWN ELEMENT=1 DEFINE RPDI1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED

& & &

& & &

F F

COMPONENT=HDPE ATTRIBUTE=PDI ELEMENT=1 DEFINE RE21 MASS-FLOW STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=C2H4 DEFINE RMI2 STREAM-PROP STREAM=R2PROD PROPERTY=MI-KAR DEFINE RMI1 STREAM-PROP STREAM=R1PROD PROPERTY=MI-KAR DEFINE R2H2 MASS-FRAC STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=H2 DEFINE R1H2 MASS-FRAC STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=H2 CONV2 = RHDPE2/(RHDPE2+RE22) * 100 CONV1 = RHDPE1/(RHDPE1+RE21) * 100 TABULATE 1 "CONV1" COL-LABEL="CONV1" TABULATE 2 "CONV2" COL-LABEL="CONV2" TABULATE 3 "RMW1" COL-LABEL="MW1" TABULATE 4 "RMW2" COL-LABEL="MW2" TABULATE 5 "RMN1" COL-LABEL="MN1" TABULATE 6 "RMN2" COL-LABEL="MN2" TABULATE 7 "RPDI1" COL-LABEL="PDI1" TABULATE 8 "RPDI2" COL-LABEL="PDI2" TABULATE 9 "R1H2*1.0E6" COL-LABEL="R1H2" "PPM" TABULATE 10 "R2H2*1.0E6" COL-LABEL="R2H2" "PPM" TABULATE 11 "RMI1" COL-LABEL="MI1" TABULATE 12 "RMI2" COL-LABEL="MI2" VARY STREAM-VAR STREAM=R1FEED SUBSTREAM=MIXED & VARIABLE=MASS-FLOW RANGE LOWER="2E4" UPPER="1.5E6" NPOINT="20"

SENSITIVITY RTIME2 PARAM BASE-CASE=LAST DEFINE RHDPE2 MASS-FLOW STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=HDPE DEFINE RMW2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWW ELEMENT=1 DEFINE RMN2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWN ELEMENT=1 DEFINE RPDI2 COMP-ATTR-VAR STREAM=R2PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=PDI ELEMENT=1 DEFINE RE22 MASS-FLOW STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=C2H4 DEFINE RHDPE1 MASS-FLOW STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=HDPE DEFINE RMW1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWW ELEMENT=1 DEFINE RMN1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=MWN ELEMENT=1 DEFINE RPDI1 COMP-ATTR-VAR STREAM=R1PROD SUBSTREAM=MIXED COMPONENT=HDPE ATTRIBUTE=PDI ELEMENT=1 DEFINE RE21 MASS-FLOW STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=C2H4 DEFINE RMI2 STREAM-PROP STREAM=R2PROD PROPERTY=MI-KAR DEFINE RMI1 STREAM-PROP STREAM=R1PROD PROPERTY=MI-KAR DEFINE R2H2 MASS-FRAC STREAM=R2PROD SUBSTREAM=MIXED & COMPONENT=H2 DEFINE R1H2 MASS-FRAC STREAM=R1PROD SUBSTREAM=MIXED & COMPONENT=H2 F CONV2 = RHDPE2/(RHDPE2+RE22) * 100 F CONV1 = RHDPE1/(RHDPE1+RE21) * 100

198

& & &

& & &


TABULATE 1 "CONV1" COL-LABEL="CONV1" TABULATE 2 "CONV2" COL-LABEL="CONV2" TABULATE 3 "RMW1" COL-LABEL="MW1" TABULATE 4 "RMW2" COL-LABEL="MW2" TABULATE 5 "RMN1" COL-LABEL="MN1" TABULATE 6 "RMN2" COL-LABEL="MN2" TABULATE 7 "RPDI1" COL-LABEL="PDI1" TABULATE 8 "RPDI2" COL-LABEL="PDI2" TABULATE 9 "R1H2*1.0E6" COL-LABEL="R1H2" "PPM" TABULATE 10 "R2H2*1.0E6" COL-LABEL="R2H2" "PPM" TABULATE 11 "RMI1" COL-LABEL="MI1" TABULATE 12 "RMI2" COL-LABEL="MI2" VARY MASS-FLOW STREAM=FEED2 SUBSTREAM=MIXED COMPONENT=H2 RANGE LOWER="0.0" UPPER="20" INCR="2.0" CONV-OPTIONS PARAM CHECKSEQ=NO SEQUENCE S-1 CSTR-1 CSTR-2 RTIME CSTR-1 CSTR-2 (RETURN RTIME) RTIME2 CSTR-2 FLASH (RETURN RTIME2) STREAM-REPOR NARROW MOLEFLOW MASSFLOW MASSFRAC PROPERTIES=DENS IV MI-KAR MI-SIN ZVIS REACTIONS ZN-R1 ZIEGLER-NAT DESCRIPTION "Ziegler-Natta Kinetic Scheme" PARAM SPECIES CATALYST=TICL4 COCATALYST=TEA MONOMER=C2H4 SOLVENT=HEXANE HYDROGEN=H2 POLYMER=HDPE MON-RSEG C2H4 C2H4-R ACT-SPON 1 TICL4 .080 0.0 ORDER=1.0 ACT-SPON 2 TICL4 .080 0.0 ORDER=1.0 ACT-SPON 3 TICL4 0.0 0.0 ORDER=1.0 ACT-SPON 4 TICL4 0.0 0.0 ORDER=1.0 ACT-COCAT 1 TICL4 TEA .150 0.0 ORDER=1.0 ACT-COCAT 2 TICL4 TEA .150 0.0 ORDER=1.0 ACT-COCAT 3 TICL4 TEA 0.0 0.0 ORDER=1.0 ACT-COCAT 4 TICL4 TEA 0.0 0.0 ORDER=1.0 CHAIN-INI 1 C2H4 255.0 0.0 ORDER=1.0 CHAIN-INI 2 C2H4 90.0 0.0 ORDER=1.0 CHAIN-INI 3 C2H4 0.0 0.0 ORDER=1.0 CHAIN-INI 4 C2H4 0.0 0.0 ORDER=1.0 PROPAGATION 1 C2H4 C2H4 255.0 0.0 ORDER=1.0 PROPAGATION 2 C2H4 C2H4 90.0 0.0 ORDER=1.0 PROPAGATION 3 C2H4 C2H4 0.0 0.0 ORDER=1.0 PROPAGATION 4 C2H4 C2H4 0.0 0.0 ORDER=1.0 CHAT-MON 1 C2H4 C2H4 .090 0.0 ORDER=1.0 CHAT-MON 2 C2H4 C2H4 .240 0.0 ORDER=1.0 CHAT-MON 3 C2H4 C2H4 0.0 0.0 ORDER=1.0 CHAT-MON 4 C2H4 C2H4 0.0 0.0 ORDER=1.0 CHAT-H2 1 C2H4 H2 5.550 0.0 ORDER=1.0 CHAT-H2 2 C2H4 H2 18.50 0.0 ORDER=1.0 CHAT-H2 3 C2H4 H2 0.0 0.0 ORDER=1.0 CHAT-H2 4 C2H4 H2 0.0 0.0 ORDER=1.0 CHAT-SPON 1 C2H4 .0040 0.0 ORDER=1.0 CHAT-SPON 2 C2H4 .0120 0.0 ORDER=1.0 CHAT-SPON 3 C2H4 0.0 0.0 ORDER=1.0

&

& &

CHAT-SPON 4 C2H4 0.0 0.0 ORDER=1.0 DEACT-SPON 1 .00010 0.0 ORDER=1.0 DEACT-SPON 2 .00060 0.0 ORDER=1.0 DEACT-SPON 3 0.0 0.0 ORDER=1.0 DEACT-SPON 4 0.0 0.0 ORDER=1.0 REACTIONS ZN-R2 ZIEGLER-NAT DESCRIPTION "Ziegler-Natta Kinetic Scheme" PARAM SPECIES CATALYST=TICL4 COCATALYST=TEA MONOMER=C2H4 SOLVENT=HEXANE HYDROGEN=H2 POLYMER=HDPE MON-RSEG C2H4 C2H4-R ACT-SPON 1 TICL4 .080 0.0 ORDER=1.0 ACT-SPON 2 TICL4 .080 0.0 ORDER=1.0 ACT-SPON 3 TICL4 .080 0.0 ORDER=1.0 ACT-SPON 4 TICL4 .080 0.0 ORDER=1.0 ACT-COCAT 1 TICL4 TEA .150 0.0 ORDER=1.0 ACT-COCAT 2 TICL4 TEA .150 0.0 ORDER=1.0 ACT-COCAT 3 TICL4 TEA .150 0.0 ORDER=1.0 ACT-COCAT 4 TICL4 TEA .150 0.0 ORDER=1.0 CHAIN-INI 1 C2H4 255.0 0.0 ORDER=1.0 CHAIN-INI 2 C2H4 90.0 0.0 ORDER=1.0 CHAIN-INI 3 C2H4 255.0 0.0 ORDER=1.0 CHAIN-INI 4 C2H4 90.0 0.0 ORDER=1.0 PROPAGATION 1 C2H4 C2H4 255.0 0.0 ORDER=1.0 PROPAGATION 2 C2H4 C2H4 90.0 0.0 ORDER=1.0 PROPAGATION 3 C2H4 C2H4 255.0 0.0 ORDER=1.0 PROPAGATION 4 C2H4 C2H4 90.0 0.0 ORDER=1.0 CHAT-MON 1 C2H4 C2H4 .090 0.0 ORDER=1.0 CHAT-MON 2 C2H4 C2H4 .240 0.0 ORDER=1.0 CHAT-MON 3 C2H4 C2H4 .090 0.0 ORDER=1.0 CHAT-MON 4 C2H4 C2H4 .240 0.0 ORDER=1.0 CHAT-H2 1 C2H4 H2 5.550 0.0 ORDER=1.0 CHAT-H2 2 C2H4 H2 18.50 0.0 ORDER=1.0 CHAT-H2 3 C2H4 H2 5.550 0.0 ORDER=1.0 CHAT-H2 4 C2H4 H2 18.50 0.0 ORDER=1.0 CHAT-SPON 1 C2H4 .0040 0.0 ORDER=1.0 CHAT-SPON 2 C2H4 .0120 0.0 ORDER=1.0 CHAT-SPON 3 C2H4 .0040 0.0 ORDER=1.0 CHAT-SPON 4 C2H4 .0120 0.0 ORDER=1.0 DEACT-SPON 1 .00010 0.0 ORDER=1.0 DEACT-SPON 2 .00060 0.0 ORDER=1.0 DEACT-SPON 3 .00010 0.0 ORDER=1.0 DEACT-SPON 4 .00060 0.0 ORDER=1.0 ;

&

Selected Simulation Results The results for the sensitivity study to determine the effect of feed flowrate to CSTR -1 on ethylene conversion, M n, Mw, PDI, and melt index are shown in the figures that follow. The effect of feed flow rate on ethylene conversion is shown here:

200


90 80 70 CSTR1

n o 60 i s r e v 50 n o C e 40 n e l y h 30 t E

CSTR2

20 10 0 0

500000

1 0 0 0 00 0

1 50 0 0 0 0

Feed Flow Rate to CSTR -1, kg/hr kg/hr

Properties of the product exiting from CSTR -2 are influenced by the flowrates of both feeds. Increasing the feed to CSTR-1 decreases the residence time in CSTR -1 and CSTR -2, as shown, this leads to a decrease in conversion in both reactors. Although conversion decreases with increases in CSTR -1 feed, the next two figures show an increase in the CSTR -2 polymer Mn and Mw. This is due to the concentration of hydrogen in CSTR -2. As CSTR -1 feed flow increases, hydrogen concentration in CSTR -2 decreases. As a result, chain transfer rate decreases, allowing longer polymer chain length.

The effect of feed flow rate on M n is shown here:

40000

35000

CSTR1 CSTR2

n M30000

25000

20000 0

500000

1000000

1500000

Feed Flow R ate to CSTR-1, kg/hr

The effect of feed flow rate on M w is shown here: 120000 115000 110000 105000 w100000 M

95000

CSTR1 CSTR2

90000 85000 80000 0

5 0 0 0 00

10 0 0 0 00

1500000

Feed Flow Rate to CSTR-1, kg/hr

The effect of feed flow rate on the hydrogen concentration (PPM) is shown here:

202


70 65 60 55

) m50 p p 45 ( n 40 o i t a r 35 t n e 30 c n 25 o C 2 20 H

CSTR1 CSTR2

15 10 5 0 0

5 0 00 0 0

10 0 0 0 0 0

1 5 0 0 0 00

Feed Flow Rate to CST R-1, kg/hr

The effect of feed flow rate on the polydispersity index is shown here: 4.2

4 CSTR1

x e 3.8 d n I y t i s r 3.6 e p s i d y l o 3.4 P

CSTR2

3.2

3 0

5 0 0 00 0

1 0 0 0 00 0

1 50 0 0 00

Feed Flow Rate to CSTR-1, kg/hr

The effect of feed flow rate on the melt index is shown here:

2.75 2.5 2.25 CSTR1

2

CSTR2

x 1.75 e d n 1.5 I t l e M1.25

1 0.75 0.5 0.25 0

5 0 0 0 00

1 0 0 0 00 0

1 50 0 0 0 0

Feed Flow Rate to CSTR -1, kg/hr kg/hr

The results for the sensitivity studies to determine the effects of hydrogen flowrate on polymer properties are shown in the three figures that follow. In this case, hydrogen flowrate in the intermediate feed to CSTR-2 is varied. As hydrogen flowrate increases, average molecular weight of HDPE in CSTR -2 decreases as shown in the first figure. The effect of hydrogen concentration on M n and Mw is shown here: 140000 120000 t 100000 h g i e W 80000 r a l u 60000 c e l o 40000 M

Mn Mw

20000 0 0

50

100

150

20 0

250

300

Hydrogen Conc. in CSTR-2, ppm

The effect of hydrogen concentration on melt index and PDI is shown here:

204


10 9 8 7 6 5 4 3

PD I

2

Melt Index

1 0 0

50

100

1 50

2 00

250

300

Hydrogen Conc. in CSTR -2, ppm

The molecular weight distribution for polymer produced at the different sites is shown here: 0.5 Composite

0.4

n o i t c 0.3 a r F t h 0.2 g i e W0.1

Site_1 Site_2 Site_3 Site_4

0.0 1

10

10 0

10 0 0

10000

1 0 0 00 0

Polymer Chain Length

As shown, although the polymer at each site follows the Flory distribution, the composite polymer MWD is quite broad. In conclusion, the studies show the importance of choosing the right operating conditions in order to optimize reactor performance and product properties.

Simulation Stream Summary A stream summary for the base case simulation is shown here: FEED2 POLYMER R1FEED R1PROD R2PROD ---------------------------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KG/HR TICL4

FEED2 ---CSTR-2

POLYMER FLASH ----

R1FEED ---CSTR-1

R1PROD CSTR-1 CSTR-2

R2PROD CSTR-2 FLASH

LIQUID

LIQUID

LIQUID

LIQUID

LIQUID

1.0000

7.0000

6.0000

6.0000

7.0000

TEA 1.5000 C2H4 2000.0000 H2 2.0000 HEXANE 7995.5000 HDPE 0.0 COMPONENTS: MASS FRAC TICL4 1.0000-04 TEA 1.5000-04 C2H4 0.2000 H2 2.0000-04 HEXANE 0.7996 HDPE 0.0 TOTAL FLOW: KMOL/HR 165.0820 KG/HR 1.0000+04 CUM/SEC 4.8344-03 STATE VARIABLES: TEMP C 70.0000 PRES ATM 200.0000 VFRAC 0.0 LFRAC 1.0000 SFRAC 0.0 ENTHALPY: J/KMOL -8.5807+07 J/KG -1.4165+06 WATT -3.9348+06 ENTROPY: J/KMOL-K -3.9499+05 J/KG-K -6520.6535 DENSITY: KMOL/CUM 9.4853 KG/CUM 574.5816 AVG MW 60.5759 COMPONENT ATTRIBUTES: TICL4 CPSFLOW CPSFLOW 1.0000-04 CPSFRAC CPSFRAC 1.0000 CVSFLOW SITE_1 0.0 SITE_2 0.0 SITE_3 0.0 SITE_4 0.0 CVSFRAC SITE_1 0.0 SITE_2 0.0 SITE_3 0.0 SITE_4 0.0 CDSFLOW CDSFLOW 0.0 CDSFRAC CDSFRAC 0.0 HDPE SFRAC C2H4-R MISSING SFLOW C2H4-R MISSING DPN

206

10.4999 7.0265 9.6960-04 2055.1866 5846.3263

9.0000 6000.0000 0.3000 5.3985+04 0.0

8.9999 2448.3134 0.2793 5.3985+04 3551.7074

10.4999 2153.7923 2.1816 6.1980+04 5846.3263

8.8316-04 1.3247-03 8.8651-04 1.2233-07 0.2593 0.7376

1.0000-04 1.5000-04 0.1000 5.0000-06 0.8997 0.0

1.0000-04 1.5000-04 4.0805-02 4.6543-06 0.8997 5.9195-02

1.0000-04 1.5000-04 3.0768-02 3.1165-05 0.8854 8.3519-02

232.6255 7926.0403 3.1006-03

840.5730 6.0000+04 2.7440-02

840.5634 6.0000+04 2.9458-02

1005.6005 7.0000+04 3.3779-02

160.0000 10.0000 0.0 1.0000 0.0

70.0000 200.0000 0.0 1.0000 0.0

160.0000 200.0000 0.0 1.0000 0.0

160.0000 200.0000 0.0 1.0000 0.0

-6.2134+07 -1.2849+08 -1.2707+08 -1.2625+08 -1.8236+06 -1.8001+06 -1.7801+06 -1.8137+06 -4.0150+06 -3.0002+07 -2.9669+07 -3.5266+07 -2.3531+05 -4.9143+05 -4.6289+05 -4.5417+05 -6906.2266 -6884.7737 -6484.7471 -6524.4803 20.8405 710.0783 34.0721

8.5092 607.3833 71.3799

7.9263 565.7847 71.3807

8.2696 575.6452 69.6102

1.7859-07

6.0000-04

1.8329-06

1.7859-07

2.5512-04

1.0000

3.0549-03

2.5512-04

7.7194-08 2.4029-07 7.2433-09 3.8375-08

0.0 0.0 0.0 0.0

1.4019-08 6.7671-08 0.0 0.0

7.7194-08 2.4029-07 7.2433-09 3.8375-08

1.1028-04 3.4327-04 1.0348-05 5.4822-05

0.0 0.0 0.0 0.0

2.3365-05 1.1279-04 0.0 0.0

1.1028-04 3.4327-04 1.0348-05 5.4822-05

3.5591-04

0.0

2.1510-04

3.5591-04

0.5084

0.0

0.3585

0.5084

1.0000

MISSING

1.0000

1.0000

208.3930

MISSING

126.6029

208.3930


DPN DPW DPW PDI PDI MWN MWN MWW MWW ZMOM ZMOM FMOM FMOM SMOM SMOM LDPN LDPN LZMOM LZMOM LFMOM LFMOM LSFLOW C2H4-R LSFRAC C2H4-R LEFLOW C2H4-R LEFRAC C2H4-R LPFRAC LPFRAC SSFRAC C2H4-R_1 C2H4-R_2 C2H4-R_3 C2H4-R_4 SSFLOW C2H4-R_1 C2H4-R_2 C2H4-R_3 C2H4-R_4 SDPN SITE_1 SITE_2 SITE_3 SITE_4 SDPW SITE_1 SITE_2 SITE_3 SITE_4 SPDI SITE_1 SITE_2 SITE_3 SITE_4 SMWN

MISSING

993.2823

MISSING

1174.3925

993.2823

MISSING

3590.2126

MISSING

4202.4206

3590.2126

MISSING

3.6145

MISSING

3.5784

3.6145

MISSING

2.7865+04

MISSING

3.2946+04

2.7865+04

MISSING

1.0072+05

MISSING

1.1789+05

1.0072+05

MISSING

0.2098

MISSING

0.1078

0.2098

MISSING

208.3930

MISSING

126.6029

208.3930

MISSING

7.4818+05

MISSING

5.3204+05

7.4818+05

MISSING

1128.9483

MISSING

1696.5667

1128.9483

MISSING

3.4355-04

MISSING

3.8299-04

3.4355-04

MISSING

0.3879

MISSING

0.6498

0.3879

MISSING

0.3879

MISSING

0.6498

0.3879

MISSING

1.0000

MISSING

1.0000

1.0000

MISSING

3.4355-04

MISSING

3.8299-04

3.4355-04

MISSING

1.0000

MISSING

1.0000

1.0000

MISSING

1.6375-03

MISSING

3.5527-03

1.6375-03

MISSING MISSING MISSING MISSING

1.0000 1.0000 1.0000 1.0000


1.0000 1.0000 MISSING MISSING

1.0000 1.0000 1.0000 1.0000


172.7769 28.1977 6.1735 1.2450


106.2438 20.3591 0.0 0.0

172.7769 28.1977 6.1735 1.2450


1940.9634 257.8342 1453.0175 173.5386


2443.8053 316.4879 0.0 0.0

1940.9634 257.8342 1453.0175 173.5386


4133.7493 553.0206 2905.0350 346.0773


4886.6106 631.9758 0.0 0.0

4133.7493 553.0206 2905.0350 346.0773


2.1297 2.1449 1.9993 1.9942


1.9996 1.9968 0.0 0.0

2.1297 2.1449 1.9993 1.9942

SITE_1 SITE_2 SITE_3 SITE_4 SMWW SITE_1 SITE_2 SITE_3 SITE_4 SZMOM SITE_1 SITE_2 SITE_3 SITE_4 SFMOM SITE_1 SITE_2 SITE_3 SITE_4 SSMOM SITE_1 SITE_2 SITE_3 SITE_4 SPFRAC SITE_1 SITE_2 SITE_3 SITE_4 LSDPN SITE_1 SITE_2 SITE_3 SITE_4 LSZMOM SITE_1 SITE_2 SITE_3 SITE_4 LSFMOM SITE_1 SITE_2 SITE_3 SITE_4 LSSFLOW C2H4-R_1 C2H4-R_2 C2H4-R_3 C2H4-R_4 LSSFRAC C2H4-R_1 C2H4-R_2 C2H4-R_3 C2H4-R_4 LSEFLOW C2H4-R_1 C2H4-R_2

208


5.4451+04 7233.2202 4.0763+04 4868.4116


6.8558+04 8878.6756 0.0 0.0

5.4451+04 7233.2202 4.0763+04 4868.4116


1.1597+05 1.5514+04 8.1497+04 9708.7695


1.3709+05 1.7729+04 0.0 0.0

1.1597+05 1.5514+04 8.1497+04 9708.7695


8.9016-02 0.1094 4.2487-03 7.1740-03


4.3475-02 6.4328-02 0.0 0.0

8.9016-02 0.1094 4.2487-03 7.1740-03


172.7769 28.1977 6.1735 1.2450


106.2438 20.3591 0.0 0.0

172.7769 28.1977 6.1735 1.2450


7.1422+05 1.5594+04 1.7934+04 430.8574


5.1917+05 1.2866+04 0.0 0.0

7.1422+05 1.5594+04 1.7934+04 430.8574


0.8291 0.1353 2.9624-02 5.9742-03


0.8392 0.1608 0.0 0.0

0.8291 0.1353 2.9624-02 5.9742-03


1466.2724 174.4783 1453.0175 173.5386


2443.8053 316.4879 0.0 0.0

1466.2724 174.4783 1453.0175 173.5386


2.3250-04 7.7217-05 2.1573-05 1.2264-05


2.4846-04 1.3453-04 0.0 0.0

2.3250-04 7.7217-05 2.1573-05 1.2264-05


0.3409 1.3473-02 3.1346-02 2.1283-03


0.6072 4.2576-02 0.0 0.0

0.3409 1.3473-02 3.1346-02 2.1283-03


0.3409 1.3473-02 3.1346-02 2.1283-03


0.6072 4.2576-02 0.0 0.0

0.3409 1.3473-02 3.1346-02 2.1283-03


1.0000 1.0000 1.0000 1.0000


1.0000 1.0000 0.0 0.0

1.0000 1.0000 1.0000 1.0000

MISSING MISSING

2.3250-04 7.7217-05

MISSING MISSING

2.4846-04 1.3453-04

2.3250-04 7.7217-05


C2H4-R_3 C2H4-R_4 LSEFRAC C2H4-R_1 C2H4-R_2 C2H4-R_3 C2H4-R_4 LSPFRAC SITE_1 SITE_2 SITE_3 SITE_4 MIXED

MISSING MISSING

2.1573-05 1.2264-05

MISSING MISSING

0.0 0.0

2.1573-05 1.2264-05


1.0000 1.0000 1.0000 1.0000


1.0000 1.0000 0.0 0.0

1.0000 1.0000 1.0000 1.0000


2.6119-03 7.0606-04 5.0775-03 1.7095-03


5.7150-03 2.0913-03 0.0 0.0

2.6119-03 7.0606-04 5.0775-03 1.7095-03

925.7174 1.0335 0.4745 0.8246 83.7338

925.7174 1.0014 0.8950 1.4246 83.1969

SUBSTREAM PROPERTIES:

*** ALL PHASES *** DENS KG/CUM IV UNITLESS MI-K UNITLESS MI-S UNITLESS ZVIS N-SEC/SQM

0.0 0.0 0.0 0.0 0.0

RECYCLE ------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KG/HR TICL4 TEA C2H4 H2 HEXANE HDPE COMPONENTS: MASS FRAC TICL4 TEA C2H4 H2 HEXANE HDPE TOTAL FLOW: KMOL/HR KG/HR CUM/SEC STATE VARIABLES: TEMP C PRES ATM VFRAC LFRAC SFRAC ENTHALPY:

RECYCLE FLASH ---VAPOR 3.0502-09 4.5753-09 2146.7657 2.1806 5.9925+04 0.0 4.9139-14 7.3707-14 3.4584-02 3.5129-05 0.9654 0.0 772.9750 6.2074+04 0.6172 160.0000 10.0000 1.0000 0.0 0.0

925.7174 1.0014 0.8950 1.4246 83.1969

0.0 0.0 0.0 0.0 0.0

J/KMOL J/KG WATT ENTROPY: J/KMOL-K J/KG-K DENSITY: KMOL/CUM KG/CUM AVG MW

-1.2586+08 -1.5673+06 -2.7025+07 -4.7043+05 -5858.0069 0.3479 27.9349 80.3053

References MacAuley, K. B., MacGregor, J. F., & Hamielec, A. E. (1990). AIChE (1990). AIChE J., J., 36, 36, p. 837. Xie, T., McAuley, K. B., Hsu, Hsu, J. C. C., & Bacon, Bacon, D. W. (1994). Gas phase ethylene polymerization: Production processes, processes, polymer properties and reactor modeling. Ind. Eng. Chem. Res., Res ., 33, 33, pp. 449-479.

210


C8 Low-Density Polyethylene High Pressure Process

The LDPE high-pressure process model illustrates the use of Aspen Polymers Plus to model a high pressure free-radical free-radical process for low-density polyethylene. The model considers the tubular jacketed reactor along with the post-polymerization devolatization. Among the parameters studied in the model are reactor temperature profile, monomer conversion, polymer molecular weight and degree of branching.

About This Process Low density polyethylene (LDPE), is part of the polyolefin family of polymers. This polymer exhibits a number of desirable properties, including strength, flexibility, impact resistance, resistance to solvents, to chemicals, and to oxidating agents. For this reason, it is one of the highest volume polymers in terms of production. LDPE is produced by free-radical polymerization. It has been produced in batch processes. However, continuous processes are more commonly found, because they allow better control of the polymerization. Polymerization is carried out in tubular and autoclave reactors under high pressure (1300-3400 atm), and high temperatures (150-340 °C). At such high compression states, the gaseous ethylene monomer behaves like a liquid. The reactor of choice for the production of LDPE is a tubular reactor. Some processes involve multizone tubular reactors with multiple initiator injection points along the length of the reactor.

Process Definition In this example, polymerization of ethylene is carried out in a jacketed tubular reactor divided into four sections, with two initiator inj ection points.

High and low pressure separators are also used. The flowsheet for the process is shown here:

212



Name

Databank

Description

Initiator

INI1

PURE12

Initiator

2nd initiator

INI2

PURE12

Initiator

Ethylene

E2

PURE12

Monomer

Polyethylene

LDPE

POLYMER

Polymer

E2-SEG

SEGMENT

Ethylene segment

Water

WATER

PURE12

Coolant

Physical Properties

POLYSL property method with supplied parameters

Feeds

E2FD1B

E2FD2B

INIFD1

INIFD2

Coolant Streams

Temperature (°C)

140

50

0

0

160

Pressure (bar)

2010

2000

2010

2010

100

Component flows: (kg/hr)

40000

25000

---

---

---

E2

---

---

6

12

---

INI1

---

---

1.5

3

---

INI2

---

---

---

---

160000

WATER Kinetics

FREE-RAD model (see Reactors / Kinetics on page 214 for rate constant parameters)


Block

Temp ( C)

Pres (atm)

Pres Drop (bar)

Size

PFR1

170 (coolant)

---

100

250 m length by 0.059 m diam*

PFR2

170 (coolant)

---

100


PFR3

170 (coolant)

---

100


PFR4

170 (coolant)

---

100


FDMIX1

---

2000

---

---

FDMIX2

---

1900

---

---

HPS

Duty=0

250

---

---

LPS

Duty=0

1

---

---

*

A user heat transfer transfer subroutine subroutine (Carr (Carr et al., 1955; Eirmann, 1965) is provided to these plug flow reactors.

Physical Property Models and Data The POLYSL equation-of-state property method is used for the physical property calculations and phase equilibria. The unary input parameters for POLYSL are SLTSTR, SLPSTR, and SLRSTR, and correspond to the SanchezLacombe equation of state T*, P*, and ρ* parameters, respectively. The parameters were obtained by Sanchez-Lacombe Sanchez-Lacombe by fitting experimental data (Sanchez & Lacombe, 1976). An input summary containing these parameter values is given in the Process Studies section on page 215 215.. To improve predictions for phase equilibria in the high- and low-pressure separators, two binary interaction parameters between polyethylene and ethylene were introduced, namely SLKIJ and SLETIJ. These parameters were obtained by fitting VLE experimental data of polyethylene-ethylene binary systems at various temperatures. An input summary containing these 215. parameter values is given in the Process Studies section on page 215. Ideal gas heat capacity coefficients (CPIG) are entered for ethylene segment and pure ethylene. The coefficients are obtained from fitting heat capacity data. CPIG is used for the calculation of ideal-gas enthalpy and entropy, which are added to the departure values calculated by the Sanchez-Lacombe equation of state. An input summary containing these parameter values is given in the Process Studies section on page 215. 215.

Reactors / Kinetics The built-in free-radical reactions used in this example are: Description

k0† (m3/kmol)

Ea† (J/kmol)

V† (m3/kmol)

Initiator 1 decomposition decomposition

2.5E14

126E6

0

Initiator 2 decomposition decomposition

5.93E18

Chain initiation

214

195E6

0

‡

35.3E6

0

‡

2.5E8

Propagation

2.5E8

35.3E6

-21.3E-3


1.25E6

45.4E6

0

Chain transfer to polymer

1.24E6

30.4E6

1.6E-3


2.5E9

4.19E6

1E-3

Termination by disproportionation disproportionation

2.5E9

4.19E6

1E-3

Beta scission

6.07E7

45.3E6

0

Short chain branching

1.3E9

41.6E6

0

†

k0 is frequency factor, E a is activation energy, and V is activation volume

‡

k0 is two times higher than in Mavridis and Kiparissides (1985).


Process Studies The model is used to examine the reactor temperature profile, monomer conversion, number and weight average molecular weights, and frequency of short and long chain branches.

Input Summary The input language summary for this example is shown here: DYNAPLUS DPLUS RESULTS=ON TITLE

&

'High-Pressure LDPE tubular reactor flowsheet with four sections' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar TEMPERATURE=C PDROP='N/sqm' DEF-STREAMS CONVEN ALL SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=5000.0 DESCRIPTION " This flowsheet models a high-pressure LDPE tubular reactor flowsheet with four sections, two initiator and monomer injection points, and high and low pressure separators. This application requires a FORTRAN subroutine to calculate the heat transfer coefficient along the reactor length. Please copy USRHPE.F located in the application directory to your working directory and compile it by typing. ASPCOMP USRHPE This subroutine locates the monomer and polymer components by looking for the names E2 and LDPE respectively. If you change component names you must update the subroutine. If you don't have compiler you can copy USERFORT.DLL and USERFORT.DLOPT from APPlication folder to the working directory, enter USERPORT.DLOPT in the Run/Settings /Engine Files/Linker Options box and run the simulation.

" DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

&

COMPONENTS INI1 C14H10O4 / E2 C2H4 / LDPE PE / E2-SEG C2H4-R / INI2 C8H18O2 / WATER H2O FLOWSHEET BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK BLOCK

PFR1 IN=FEED1 CIN1 OUT=OUT1 COUT1 PFR2 IN=OUT1 CIN2 OUT=OUT2 COUT2 FDMIX2 IN=OUT2 INIFD2 E2FD2B OUT=FEED2 PFR3 IN=FEED2 CIN3 OUT=OUT3 COUT3 PFR4 IN=OUT3 CIN4 OUT=OUT4 COUT4 HPS IN=OUT4 OUT=HP-RECY HPSB LPS IN=HPSB OUT=LP-RECY LPSB FDMIX1 IN=E2FD1B INIFD1 OUT=FEED1 FSPLIT1 IN=E2FD OUT=E2FD2A E2FD1A EFD1 IN=E2FD1A OUT=E2FD1B EFD2 IN=E2FD2A OUT=E2FD2B

PROPERTIES POLYSL PROPERTIES STEAM-TA PROP-DATA POLYSL IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar PDROP='N/sqm' PROP-LIST SLTSTR / SLPSTR / SLRSTR PVAL E2 333.0 / 2400.0 / 631.0 PVAL LDPE 667.70 / 3500.0 / 894.0 PVAL INI1 530 / 3040 / 1120 PVAL INI2 530 / 3040 / 1120 PVAL WATER 623.0 / 2.6871390E+04 / 1105.0 PROP-DATA TGTM IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar TEMPERATURE=C PDROP='N/sqm' PROP-LIST TGVK / TMVK / CRITMW PVAL LDPE -36.0 / 141.60 / 3500.0 PROP-DATA VLSTD IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar TEMPERATURE=C PDROP='N/sqm' PROP-LIST VLSTD PVAL E2-SEG 0.0 PROP-DATA CPIG-1 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar TEMPERATURE=C PDROP='N/sqm' PROP-LIST CPIG PVAL E2-SEG 35342.0 70.20 PVAL E2 42291.0 47.3550 PROP-DATA MULMH-1 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' PRESSURE=bar TEMPERATURE=C PDROP='N/sqm'

216

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&


PROP-LIST MULMH PVAL LDPE .0005740 5000.0 7.54220 1.0 1.0 PROP-DATA SLETIJ-1 IN-UNITS SI PROP-LIST SLETIJ BPVAL LDPE E2 -.15 BPVAL E2 LDPE -.15 PROP-DATA SLKIJ-1 IN-UNITS SI PROP-LIST SLKIJ BPVAL LDPE E2 .04 BPVAL E2 LDPE .04 POLYMERS SEGMENTS E2-SEG REPEAT POLYMERS LDPE ATTRIBUTES LDPE DPN DPW PDI MWN MWW ZMOM FMOM SMOM & SFLOW SFRAC FLCB FSCB LCB SCB LSFLOW LSFRAC LEFLOW LEFRAC

&

STREAM CIN1 SUBSTREAM MIXED TEMP=160.0 PRES=100.0 NPHASE=1 PHASE=L MASS-FLOW WATER 160000.0 STREAM CIN2 SUBSTREAM MIXED TEMP=160.0 PRES=100.0 NPHASE=1 PHASE=L MASS-FLOW WATER 160000.0 STREAM CIN3 SUBSTREAM MIXED TEMP=160.0 PRES=100.0 NPHASE=1 PHASE=L MASS-FLOW WATER 160000.0 STREAM CIN4 SUBSTREAM MIXED TEMP=160.0 PRES=100.0 NPHASE=1 PHASE=L MASS-FLOW WATER 160000.0 STREAM E2FD SUBSTREAM MIXED TEMP=100. PRES=2020. MASS-FLOW E2 65000. STREAM E2FD1B SUBSTREAM MIXED TEMP=140. PRES=2010. MASS-FLOW E2 40000. STREAM E2FD2B SUBSTREAM MIXED TEMP=50. PRES=2000. MASS-FLOW E2 25000. STREAM FEED1 SUBSTREAM MIXED TEMP=140. PRES=2000.0 MASS-FLOW=63000.0 NPHASE=1 PHASE=L MASS-FRAC INI1 2.2E-005 / E2 0.999976 / INI2 1.1E-005 STREAM INIFD1 SUBSTREAM MIXED TEMP=0. PRES=2010.

&

MASS-FLOW INI1 6. / INI2 1.5 STREAM INIFD2 SUBSTREAM MIXED TEMP=0. PRES=2010. NPHASE=1 PHASE=L MASS-FLOW INI1 12. / INI2 3. BLOCK FDMIX1 MIXER PARAM PRES=2000. NPHASE=1 PHASE=L BLOCK-OPTION FREE-WATER=NO BLOCK FDMIX2 MIXER PARAM PRES=1900. NPHASE=1 PHASE=L BLOCK FSPLIT1 FSPLIT MASS-FLOW E2FD1A 40000. BLOCK EFD1 HEATER PARAM TEMP=140. PRES=-10. NPHASE=1 PHASE=L BLOCK-OPTION FREE-WATER=NO BLOCK EFD2 HEATER PARAM TEMP=50. PRES=-20. NPHASE=1 PHASE=L BLOCK-OPTION FREE-WATER=NO BLOCK HPS FLASH2 PARAM PRES=250.0 DUTY=0.0 BLOCK LPS FLASH2 PARAM PRES=1.0 DUTY=0.0 BLOCK PFR1 RPLUG SUBROUTINE QTRANS=USRHPE USER-VECS NREALQ=2 REALQ VALUE-LIST=40. 100. PARAM TYPE=COUNTER-COOL LENGTH=250.0 DIAM=.0590 NPHASE=1 PHASE=L PDROP=100. NPOINT=40 INT-TOL=1E-005 & CORR-METHOD=DIRECT ERR-METHOD=STATIC COOLANT PDROP=4. NPHASE=1 PHASE=L TEMP=170.0 PROPERTIES POLYSL / STEAM-TA REACTIONS RXN-IDS=R1 BLOCK PFR2 RPLUG SUBROUTINE QTRANS=USRHPE USER-VECS NREALQ=2 REALQ VALUE-LIST=40. 100. PARAM TYPE=COUNTER-COOL LENGTH=220.0 DIAM=.0590 NPHASE=1 PHASE=L PDROP=100. NPOINT=20 INT-TOL=1E-005 & CORR-METHOD=DIRECT ERR-METHOD=STATIC COOLANT PDROP=4. NPHASE=1 PHASE=L TEMP=170.0 PROPERTIES POLYSL / STEAM-TA REACTIONS RXN-IDS=R1 BLOCK PFR3 RPLUG SUBROUTINE QTRANS=USRHPE USER-VECS NREALQ=2 REALQ VALUE-LIST=40. 100. PARAM TYPE=COUNTER-COOL LENGTH=250.0 DIAM=.0590 NPHASE=1

218

&

&

&


PHASE=L PDROP=100. NPOINT=40 INT-TOL=1E-005 CORR-METHOD=DIRECT ERR-METHOD=STATIC COOLANT PDROP=4. NPHASE=1 PHASE=L TEMP=170.0 PROPERTIES POLYSL / STEAM-TA REACTIONS RXN-IDS=R1

&

BLOCK PFR4 RPLUG SUBROUTINE QTRANS=USRHPE USER-VECS NREALQ=2 REALQ VALUE-LIST=40. 100. PARAM TYPE=COUNTER-COOL LENGTH=220.0 DIAM=.0590 NPHASE=1 PHASE=L PDROP=100. NPOINT=20 INT-TOL=1E-005 & CORR-METHOD=DIRECT ERR-METHOD=STATIC COOLANT PDROP=4. NPHASE=1 PHASE=L TEMP=170.0 PROPERTIES POLYSL / STEAM-TA REACTIONS RXN-IDS=R1

&

EO-CONV-OPTI CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC PROPERTY-REP NOPCES REACTIONS R1 FREE-RAD DESCRIPTION "Free-Radical Kinetic Scheme" PARAM QSSA=YES SPECIES INITIATOR=INI1 INI2 MONOMER=E2 POLYMER=LDPE MON-RSEG E2 E2-SEG INIT-DEC INI1 2.5000E+14 1.2600E+08 0.0 EFFIC=0.4 NRADS=2 INIT-DEC INI2 5.93E+018 1.9500E+08 0.0 EFFIC=0.4 NRADS=2 CHAIN-INI E2 2.5000E+08 3.5300E+07 0.0 PROPAGATION E2 E2 2.5000E+08 3.5300E+07 -.02130 CHAT-MON E2 E2 1250000.0 4.5400E+07 0.0 CHAT-POL E2 E2 1240000.0 3.0400E+07 .00160 B-SCISSION E2 6.0700E+07 4.5300E+07 0.0 TERM-DIS E2 E2 2.5000E+09 4190000.0 .0010 TERM-COMB E2 E2 2.5000E+09 4190000.0 .0010 SC-BRANCH E2 E2 1.3000E+09 4.1600E+07 0.0

Selected Simulation Results This model was used to study several process parameters for the production of LDPE. The parameters evaluated for the first reactor section (PFR1) are plotted in the figures that follow. DPn and DPw versus reactor length for PFR1 is shown here:

5000 4500 n 4000 o i t a 3500 z i r e 3000 m y 2500 l o P 2000 f o e 1500 e r g 1000 e D 500

DPN DPW

0 0

50

100

150

200

250

Length, m

Initiator decomposition rate versus reactor length for PFR1 is shown here: 2.00E-05 INI1

n o 1.50E-05 i t c a r F e 1.00E-05 l o M r o t a i t 5.00E-06 i n I

INI2

0.00E+00 0

50

100

150

200

250

Length, m

Coolant and reactant temperature profiles for PFR1 are shown here:

220


350 300 ) C ( 250 e r u t a r e p 200 m e T

Process Coolant

150 100 0

50

100

150

200

250

Length, m

The remaining ethylene mole fraction profile in PFR1 and PFR3 is shown here: 1 PFR1

n 0.95 o i t c a r F 0.9 e l o M0.85 e n e l y h t 0.8 E

PFR3

0.75 0

50

100

150

Length, m

The reactor temperature profiles are shown here:

200

250

350

300

PFR1

) C ( 250 e r u t a r e p 200 m e T

PFR2 PFR3 PFR4

150

100 0

50

100

150

200

250

Length, m

Simulation Stream Summary The stream summary for this example is shown here: CIN1 CIN2 CIN3 CIN4 COUT1 ------------------------STREAM ID FROM : TO :

CIN1 ---PFR1

SUBSTREAM: MIXED PHASE: LIQUID COMPONENTS: KMOL/HR INI1 0.0 E2 0.0 LDPE 0.0 INI2 0.0 WATER 8881.3496 COMPONENTS: KG/HR INI1 0.0 E2 0.0 LDPE 0.0 INI2 0.0 WATER 1.6000+05 COMPONENTS: MASS FRAC INI1 0.0 E2 0.0 LDPE 0.0 INI2 0.0 WATER 1.0000

222

CIN2 ---PFR2

CIN3 ---PFR3

CIN4 ---PFR4

COUT1 PFR1 ----

LIQUID

LIQUID

LIQUID

LIQUID

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 1.0000


TOTAL FLOW: KMOL/HR KG/HR CUM/SEC STATE VARIABLES: TEMP C PRES BAR VFRAC LFRAC SFRAC ENTHALPY: J/KMOL J/KG WATT ENTROPY: J/KMOL-K J/KG-K DENSITY: KMOL/CUM KG/CUM AVG MW

8881.3496 1.6000+05 4.8564-02

8881.3496 1.6000+05 4.8899-02

8881.3496 1.6000+05 4.8556-02

8881.3496 1.6000+05 4.8704-02

8881.3496 1.6000+05 4.9225-02

157.6171 100.0000 0.0 1.0000 0.0

164.1454 100.0000 0.0 1.0000 0.0

157.4568 100.0000 0.0 1.0000 0.0

160.3683 100.0000 0.0 1.0000 0.0

170.0000 96.0000 0.0 1.0000 0.0

-2.7564+08 -2.7514+08 -2.7565+08 -2.7543+08 -2.7468+08 -1.5300+07 -1.5272+07 -1.5301+07 -1.5289+07 -1.5247+07 -6.8002+08 -6.7877+08 -6.8005+08 -6.7950+08 -6.7766+08 -1.3543+05 -1.3427+05 -1.3546+05 -1.3494+05 -1.3322+05 -7517.7040 -7452.9519 -7519.3030 -7490.3316 -7394.9629 50.7995 915.1666 18.0153

50.4520 908.9073 18.0153

50.8079 915.3180 18.0153

50.6543 912.5509 18.0153

50.1180 902.8902 18.0153

COUT2 PFR2 ----

COUT3 PFR3 ----

COUT4 PFR4 ----

E2FD ---FSPLIT1

E2FD1A FSPLIT1 EFD1

LIQUID

LIQUID

LIQUID

VAPOR

VAPOR

COUT2 COUT3 COUT4 E2FD E2FD1A ----------------------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR INI1 E2 LDPE INI2 WATER COMPONENTS: KG/HR INI1 E2 LDPE INI2 WATER COMPONENTS: MASS FRAC INI1 E2 LDPE INI2 WATER TOTAL FLOW: KMOL/HR KG/HR CUM/SEC STATE VARIABLES: TEMP C PRES BAR VFRAC

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 8881.3496

0.0 0.0 0.0 0.0 8881.3496

0.0 2316.9800 0.0 0.0 0.0

0.0 1425.8338 0.0 0.0 0.0

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.6000+05

0.0 0.0 0.0 0.0 1.6000+05

0.0 6.5000+04 0.0 0.0 0.0

0.0 4.0000+04 0.0 0.0 0.0

0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 1.0000

0.0 1.0000 0.0 0.0 0.0

0.0 1.0000 0.0 0.0 0.0

8881.3496 1.6000+05 4.9225-02

8881.3496 1.6000+05 4.9225-02

8881.3496 1.6000+05 4.9225-02

2316.9800 6.5000+04 3.2683-02

1425.8338 4.0000+04 2.0113-02

170.0000 96.0000 0.0

170.0000 96.0000 0.0

170.0000 96.0000 0.0

100.0000 2020.0000 1.0000

100.0000 2020.0000 1.0000

LFRAC SFRAC ENTHALPY: J/KMOL J/KG WATT ENTROPY: J/KMOL-K J/KG-K DENSITY: KMOL/CUM KG/CUM AVG MW

1.0000 0.0

1.0000 0.0

1.0000 0.0

-2.7468+08 -2.7468+08 -2.7468+08 -1.5247+07 -1.5247+07 -1.5247+07 -6.7766+08 -6.7766+08 -6.7766+08

0.0 0.0

0.0 0.0

5.3717+07 1.9148+06 3.4573+07

5.3717+07 1.9148+06 2.1276+07

-1.3322+05 -1.3322+05 -1.3322+05 -1.1907+05 -1.1907+05 -7394.9629 -7394.9629 -7394.9629 -4244.2535 -4244.2535 50.1180 902.8902 18.0153

50.1180 902.8902 18.0153

50.1180 902.8902 18.0153

19.6923 552.4417 28.0538

19.6923 552.4417 28.0538

E2FD2B EFD2 FDMIX2

FEED1 FDMIX1 PFR1

FEED2 FDMIX2 PFR3

E2FD1B E2FD2A E2FD2B FEED1 FEED2 -------------------------------STREAM ID FROM : TO :

E2FD1B EFD1 FDMIX1

E2FD2A FSPLIT1 EFD2

SUBSTREAM: MIXED PHASE: LIQUID VAPOR LIQUID LIQUID LIQUID COMPONENTS: KMOL/HR INI1 0.0 0.0 0.0 2.4770-02 4.9539-02 E2 1425.8338 891.1461 891.1461 1425.8338 2147.5521 LDPE 0.0 0.0 0.0 0.0 169.6952 INI2 0.0 0.0 0.0 1.0258-02 2.0516-02 WATER 0.0 0.0 0.0 0.0 0.0 COMPONENTS: KG/HR INI1 0.0 0.0 0.0 6.0000 12.0000 E2 4.0000+04 2.5000+04 2.5000+04 4.0000+04 6.0247+04 LDPE 0.0 0.0 0.0 0.0 4760.5891 INI2 0.0 0.0 0.0 1.5000 3.0000 WATER 0.0 0.0 0.0 0.0 0.0 COMPONENTS: MASS FRAC INI1 0.0 0.0 0.0 1.4997-04 1.8455-04 E2 1.0000 1.0000 1.0000 0.9998 0.9266 LDPE 0.0 0.0 0.0 0.0 7.3214-02 INI2 0.0 0.0 0.0 3.7493-05 4.6138-05 WATER 0.0 0.0 0.0 0.0 0.0 TOTAL FLOW: KMOL/HR 1425.8338 891.1461 891.1461 1425.8689 2317.3174 KG/HR 4.0000+04 2.5000+04 2.5000+04 4.0007+04 6.5023+04 CUM/SEC 2.0772-02 1.2570-02 1.2129-02 2.0803-02 3.3515-02 STATE VARIABLES: TEMP C 140.0000 100.0000 50.0000 140.6072 145.4816 PRES BAR 2010.0000 2020.0000 2000.0000 2000.0000 1900.0000 VFRAC 0.0 1.0000 0.0 0.0 0.0 LFRAC 1.0000 0.0 1.0000 1.0000 1.0000 SFRAC 0.0 0.0 0.0 0.0 0.0 ENTHALPY: J/KMOL 5.5884+07 5.3717+07 5.1043+07 5.5875+07 4.8595+07 J/KG 1.9920+06 1.9148+06 1.8195+06 1.9914+06 1.7319+06 WATT 2.2134+07 1.3297+07 1.2635+07 2.2131+07 3.1281+07 ENTROPY: J/KMOL-K -1.1342+05 -1.1907+05 -1.2647+05 -1.1331+05 -1.1659+05

224


J/KG-K -4043.0332 -4244.2535 -4508.1238 -4038.3549 -4155.2568 DENSITY: KMOL/CUM 19.0672 19.6923 20.4089 19.0396 19.2061 KG/CUM 534.9065 552.4417 572.5456 534.2197 538.9116 AVG MW 28.0538 28.0538 28.0538 28.0583 28.0594 COMPONENT ATTRIBUTES: LDPE DPN DPN MISSING MISSING MISSING MISSING 1204.7748 DPW DPW MISSING MISSING MISSING MISSING 4334.8385 PDI PDI MISSING MISSING MISSING MISSING 3.5980 MWN MWN MISSING MISSING MISSING MISSING 3.3798+04 MWW MWW MISSING MISSING MISSING MISSING 1.2161+05 ZMOM ZMOM MISSING MISSING MISSING MISSING 0.1406 FMOM FMOM MISSING MISSING MISSING MISSING 169.4279 SMOM SMOM MISSING MISSING MISSING MISSING 7.3444+05 SFLOW E2-SEG MISSING MISSING MISSING MISSING 169.4279 SFRAC E2-SEG MISSING MISSING MISSING MISSING 1.0000 FLCB FLCBN MISSING MISSING MISSING MISSING 0.3476 FSCB FSCBN MISSING MISSING MISSING MISSING 26.5545 LCB LCBN MISSING MISSING MISSING MISSING 5.8890-02 SCB SCBN MISSING MISSING MISSING MISSING 4.4991 LSFLOW E2-SEG MISSING MISSING MISSING MISSING 0.0 LSFRAC E2-SEG MISSING MISSING MISSING MISSING 0.0 LEFLOW E2-SEG MISSING MISSING MISSING MISSING 0.0 LEFRAC E2-SEG MISSING MISSING MISSING MISSING 0.0 HP-RECY HPSB INIFD1 INIFD2 LP-RECY ---------------------------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR INI1 E2 LDPE INI2

HP-RECY HPS ----

HPSB HPS LPS

INIFD1 ---FDMIX1

INIFD2 ---FDMIX2

LP-RECY LPS ----

VAPOR

LIQUID

LIQUID

LIQUID

VAPOR

0.0 1829.6532 0.0 0.0

0.0 51.0738 437.0550 0.0

2.4770-02 0.0 0.0 1.0258-02

4.9539-02 0.0 0.0 2.0516-02

0.0 50.9159 0.0 0.0

WATER 0.0 COMPONENTS: KG/HR INI1 0.0 E2 5.1329+04 LDPE 0.0 INI2 0.0 WATER 0.0 COMPONENTS: MASS FRAC INI1 0.0 E2 1.0000 LDPE 0.0 INI2 0.0 WATER 0.0 TOTAL FLOW: KMOL/HR 1829.6532 KG/HR 5.1329+04 CUM/SEC 8.9115-02 STATE VARIABLES: TEMP C 262.7789 PRES BAR 250.0000 VFRAC 1.0000 LFRAC 0.0 SFRAC 0.0 ENTHALPY: J/KMOL 6.1408+07 J/KG 2.1889+06 WATT 3.1210+07 ENTROPY: J/KMOL-K -7.5346+04 J/KG-K -2685.7755 DENSITY: KMOL/CUM 5.7032 KG/CUM 159.9951 AVG MW 28.0538 COMPONENT ATTRIBUTES: LDPE DPN DPN MISSING DPW DPW MISSING PDI PDI MISSING MWN MWN MISSING MWW MWW MISSING ZMOM ZMOM MISSING FMOM FMOM MISSING SMOM SMOM MISSING SFLOW E2-SEG MISSING SFRAC E2-SEG MISSING FLCB FLCBN MISSING

226

0.0

0.0

0.0

0.0

0.0 1432.8126 1.2261+04 0.0 0.0

6.0000 0.0 0.0 1.5000 0.0

12.0000 0.0 0.0 3.0000 0.0

0.0 1428.3826 0.0 0.0 0.0

0.0 0.1046 0.8954 0.0 0.0

0.8000 0.0 0.0 0.2000 0.0

0.8000 0.0 0.0 0.2000 0.0

0.0 1.0000 0.0 0.0 0.0

488.1288 1.3694+04 5.9683-03

3.5028-02 7.5000 1.8926-06

7.0055-02 15.0000 3.7852-06

50.9159 1428.3826 0.6322

262.7789 250.0000 0.0 1.0000 0.0

0.0 2010.0000 0.0 1.0000 0.0

0.0 2010.0000 0.0 1.0000 0.0

264.7096 1.0000 1.0000 0.0 0.0

-3.0694+07 -3.1707+08 -3.1707+08 -1.0941+06 -1.4808+06 -1.4808+06 -4.1619+06 -3085.0561 -6170.1122

6.4279+07 2.2913+06 9.0912+05

-1.7337+05 -8.1205+05 -8.1205+05 -2.4668+04 -6179.9927 -3792.5618 -3792.5618 -879.3212 22.7187 637.3438 28.0538

5.1411 1100.7884 214.1170

5.1411 1100.7884 214.1170

2.2372-02 0.6276 28.0538

1109.1855

MISSING

MISSING

MISSING

5901.7459

MISSING

MISSING

MISSING

5.3208

MISSING

MISSING

MISSING

3.1117+04

MISSING

MISSING

MISSING

1.6557+05

MISSING

MISSING

MISSING

0.3933

MISSING

MISSING

MISSING

436.2529

MISSING

MISSING

MISSING

2.5747+06

MISSING

MISSING

MISSING

436.2529

MISSING

MISSING

MISSING

1.0000

MISSING

MISSING

MISSING

0.6653

MISSING

MISSING

MISSING


FSCB FSCBN LCB LCBN SCB SCBN LSFLOW E2-SEG LSFRAC E2-SEG LEFLOW E2-SEG LEFRAC E2-SEG

MISSING

28.7473

MISSING

MISSING

MISSING

MISSING

0.2902

MISSING

MISSING

MISSING

MISSING

12.5411

MISSING

MISSING

MISSING

MISSING

0.0

MISSING

MISSING

MISSING

MISSING

0.0

MISSING

MISSING

MISSING

MISSING

0.0

MISSING

MISSING

MISSING

MISSING

0.0

MISSING

MISSING

MISSING

OUT1 PFR1 PFR2

OUT2 PFR2 FDMIX2

OUT3 PFR3 PFR4

OUT4 PFR4 HPS

LIQUID

LIQUID

LIQUID

LIQUID

LPSB OUT1 OUT2 OUT3 OUT4 -----------------------STREAM ID FROM : TO :

LPSB LPS ----

SUBSTREAM: MIXED PHASE: LIQUID COMPONENTS: KMOL/HR INI1 0.0 E2 0.1579 LDPE 437.0550 INI2 0.0 WATER 0.0 COMPONENTS: KG/HR INI1 0.0 E2 4.4300 LDPE 1.2261+04 INI2 0.0 WATER 0.0 COMPONENTS: MASS FRAC INI1 0.0 E2 3.6118-04 LDPE 0.9996 INI2 0.0 WATER 0.0 TOTAL FLOW: KMOL/HR 437.2129 KG/HR 1.2265+04 CUM/SEC 4.8136-03 STATE VARIABLES: TEMP C 264.7096 PRES BAR 1.0000 VFRAC 0.0 LFRAC 1.0000 SFRAC 0.0 ENTHALPY: J/KMOL -4.1755+07 J/KG -1.4884+06 WATT -5.0710+06 ENTROPY:

0.0 1256.4059 169.6952 0.0 0.0

0.0 1256.4059 169.6952 0.0 0.0

0.0 1880.7270 437.0550 0.0 0.0

0.0 1880.7270 437.0550 0.0 0.0

0.0 3.5247+04 4760.5891 0.0 0.0

0.0 3.5247+04 4760.5891 0.0 0.0

0.0 5.2761+04 1.2261+04 0.0 0.0

0.0 5.2761+04 1.2261+04 0.0 0.0

0.0 0.8810 0.1190 0.0 0.0

0.0 0.8810 0.1190 0.0 0.0

0.0 0.8114 0.1886 0.0 0.0

0.0 0.8114 0.1886 0.0 0.0

1426.1012 4.0008+04 2.1985-02

1426.1012 4.0008+04 2.1512-02

2317.7820 6.5023+04 3.6219-02

2317.7820 6.5023+04 3.5501-02

243.8088 1900.0000 0.0 1.0000 0.0

202.7850 1800.0000 0.0 1.0000 0.0

278.5977 1800.0000 0.0 1.0000 0.0

237.8896 1700.0000 0.0 1.0000 0.0

4.9898+07 1.7787+06 1.9767+07

4.7084+07 1.6783+06 1.8652+07

4.4866+07 1.5993+06 2.8886+07

4.2011+07 1.4975+06 2.7048+07

J/KMOL-K -1.8722+05 -1.0741+05 -1.1198+05 -1.0825+05 -1.1258+05 J/KG-K -6673.7654 -3828.7824 -3991.4944 -3858.7028 -4012.9062 DENSITY: KMOL/CUM 25.2300 18.0187 18.4148 17.7760 18.1354 KG/CUM 707.7974 505.4927 516.6047 498.6843 508.7674 AVG MW 28.0538 28.0538 28.0538 28.0538 28.0538 COMPONENT ATTRIBUTES: LDPE DPN DPN 1109.1855 1204.7748 1204.7748 1109.1855 1109.1855 DPW DPW 5901.7459 4334.8385 4334.8385 5901.7459 5901.7459 PDI PDI 5.3208 3.5980 3.5980 5.3208 5.3208 MWN MWN 3.1117+04 3.3798+04 3.3798+04 3.1117+04 3.1117+04 MWW MWW 1.6557+05 1.2161+05 1.2161+05 1.6557+05 1.6557+05 ZMOM ZMOM 0.3933 0.1406 0.1406 0.3933 0.3933 FMOM FMOM 436.2529 169.4279 169.4279 436.2529 436.2529 SMOM SMOM 2.5747+06 7.3444+05 7.3444+05 2.5747+06 2.5747+06 SFLOW E2-SEG 436.2529 169.4279 169.4279 436.2529 436.2529 SFRAC E2-SEG 1.0000 1.0000 1.0000 1.0000 1.0000 FLCB FLCBN 0.6653 0.3476 0.3476 0.6653 0.6653 FSCB FSCBN 28.7473 26.5545 26.5545 28.7473 28.7473 LCB LCBN 0.2902 5.8890-02 5.8890-02 0.2902 0.2902 SCB SCBN 12.5411 4.4991 4.4991 12.5411 12.5411 LSFLOW E2-SEG 0.0 0.0 0.0 0.0 0.0 LSFRAC E2-SEG 0.0 0.0 0.0 0.0 0.0 LEFLOW E2-SEG 0.0 0.0 0.0 0.0 0.0 LEFRAC E2-SEG 0.0 0.0 0.0 0.0 0.0

References Brandup, J., & Immergut, E. H. (1989). Polymer Handbook , 3rd Ed. NewYork: John Wiley. Carr, N. L., Parent, J. D., & Peck, R. E. (1955). Viscosity of Gases and Gas Mixtures at High Pressures. Chem. Eng. Progr. Symposium Ser . No. 16, 51, 91. Danner, R. P., & High, M. S. (1982). Handbook of Polymer Solution Thermodynamics. DIPPR.

228


Eirmann, K. (1965). Modellmässige Deutung de Wärmeleitfahigkeit von Hochpolymeren. Koll. Z ., ., 201, 201, p. 3. Hellwege, K. H., Knoppf, W., & Wetzel, W. (1962). Spezifische Wäarme von Polyolefinen und einigen anderen Hochpolymeren im Temperaturbereich von 300°C - 180°C. Koll. Z ., ., 180, 180, p. 126. Mavridis, I., & Kiparissides, C. (1985). Optimization of a High-Pressure Polyethylene Tubular Reactor. Polymer Process Engineering, Engineering , 3(3), pp. 263290. Michels, A., & Geldermans, M. (1942). Isotherms of Ethylene Up to 3,000 Atmospheres Between 0°C and 150°C. Physica, Physica, 9, p. 967. Odian, G. (1991). Principles of Polymerization, Polymerization , 3rd Ed. New York: John Wiley and Sons. Sanchez, I. C., & Lacombe, R. H. (1976). An Elementary Molecular Theory of Chemical Fluids. Pure Fluids. J. Fluids. J. Phys. Chem., Chem., 80(21), 80(21), pp. 2352-2362. Sanchez, I. C., & Lacombe, R. H. (1978). Statistical Thermodynamics of Polymer Solutions. Macromolecules, Macromolecules, 11(6), 11(6), pp. 1145-1156.

C9 Nylon 6 Caprolactam Polymerization Process

The nylon 6 caprolactam polymerization process model illustrates the use of Aspen Polymers Plus to simulate the polymerization of caprolactam to Nylon 6. This multistage reactor model accounts for the step-growth polymerization kinetics. This model is used to study the effect of feed flow rate on caprolactam conversion, degree of polymerization, and extraction value.

About This Process Nylon 6 is produced industrially on a large scale for synthetic fibers, films, plastics, etc. In one process, it is obtained by polymerizing caprolactam in the presence of water in a continuous flowsheet. Process modeling plays an important role in quality control, modification of existing plants, development of new processes, etc. Nylon is commonly produced in a conventional VK column reactor. The reactor is essentially a vertical tube operating at atmospheric pressure. A mixture of caprolactam, water and stabilizer is continuously fed to the top of the column. The ring opening reaction initiates polymerization in zone 1 and the excess water is evaporated in this zone. The vapor coming out of zone 1 is sent to a distillation column. Caprolactam from the distillation column is recycled to the reactor and condensate water is removed. In zone 2, polymerization proceeds under near adiabatic conditions. No water is evaporated in this zone. A representation of a conventional VK column is shown here:

230


The feed to the process is a mixture of caprolactam (99% by weight) and water (1% by weight) at 260 °C, 1 atm. When this mixture is heated to temperatures above 220-260°C, five main equilibrium reactions occur: •

Ring opening of caprolactam

•

Polycondensation of the end groups

•

Polyaddition of caprolactam

•

Ring opening of cyclic dimmer

•

Polyaddition of cyclic dimer.

The model must account for all of these reactions.

Process Definition In this example, the top portion of the VK column (zone 1) will be modeled as two stirred tank reactors. The bottom portion of the column (zone 2 and below) will be modeled as a plug flow reactor. The distillation column will be included in the simulations as a multistage separator. A flash tank will be inserted after each stirred tank in zone 1 to account for VLE calculations. The plug flow reactor will be considered liquid filled.

The flowsheet consists of two RCSTR in series, with a Flash2 in the middle, a second Flash2 followed by an RPlug, and finally a RadFrac block for the watercaprolactam separation:

Process Conditions The process conditions are:

232

Components

Name

Databank

Description

Caprolactam

CL

PURE12

Monomer

Aminocaproic Acid

ACA

PURE12

Monomer

Cyclic Dimer

CD

PURE12

Monomer

Water

H2O

PURE12

Catalyst

Nylon

NYLON

POLYMER

Polymer

T-NH2

SEGMENT

NH2 segment


Physical Properties

T-COOH

SEGMENT

COOH segment

B-ACA

SEGMENT

ACA segment


Feeds Temperature (°C)

260

Pressure (atm)

1

Flowrate (kg/hr)

40

Caprolactam

99.0% by weight

Water

1.0% by weight

Kinetics

STEP-GROWTH model


Block

Temp ( C)

Pres (atm)

Size

CSTR-1

260

1

10 m3 (7.5 m3 liquid)

CSTR-2

260

1

10 m3 (all liquid)

PLUG

260

1

20 m length by 1.85 m diam

DISTIL

---

1

19 total condenser, reflux ratio of 3

Physical Property Models and Data The Polymer Non-Random Two Liquid activity coefficient model property method (POLYNRTL) is used. Antoine constants for vapor pressure are entered for the components.

Reaction Kinetics The main reactions used in the step-growth kinetics are: Description 1

Ring-opening of caprolactam

2

Polycondensation

Reaction NH(CH 2)5

CO + H2O

NH2 + HOOC 3

Polyaddition of caprolactam

4

Ring-opeining of cyclic dimer

5

Polyaddition of cyclic dimer

NH NH2 + CO (CH2)5 - NH

H 2N (CH 2)5 COOH

NHCO

+ H2O

NHCO - (CH2)5 - NH2

NH(CH2)5CONH(CH2)5CO + H 2O

NH2 + NH(CH 2)5CONH(CH2)5CO

H2N(CH2)5 CONH(CH2)5

COOH

NHCO(CH2)5NHCO(CH2 )5 NH2

A set of rate parameters reported in the literature was used in this example and is given here:

(f) 5.9874x105

Ring opening of caprolactam

(r) 3.1663x10

Polycondensation

7

(f) 1.8942x10 10

19.88 17.962 23.271 29.216

(r) 1.17802x10 10 (r) 9.4153x10 10

22.845 26.888

18.806

2.2779x10

9

16.88

1.2114x10

1

20.670

0

26.616

7.5338x10

(f) 2.8558x109

Polayaddition of caprolactam

4.3075x10 7

9

1.6377x10 1 0

20.107 24.151

5.3993x10 1 1

Ring opening of cyclic dimer

(f) 8.5778x10 11

42.000 51.600

(r) 1.2793x10 15

o= uncatalyzed in kg/mol/h,

(r) 1.9169x10

c = catalyzed in

2 1

5

8

21.300 24.469

3.011x10 9 2.2458x10

f = f = forward reaction ,

37.400 47.000

3.4761x10

(f) 2.5701x108

Polyaddition of cyclic dimer

2.3307x10 1

and

20.400 9

23.569

r = r = reverse reaction

in kcal/mol

The polycondensation reaction is modeled using the step-growth kinetics. The functionality of the amine and acid end groups are defined in the step-growth Species sheet, as shown here:

The model generates the reaction network based on these functional groups. To keep the model consistent with Tai and Tagawa, we have cleared the

234


reaction generation option for re-arrangement reactions on the Options sheet, as shown here:

Note the Concentration basis has been set to mol/kg—this mol/kg—this forces the model to use the same mass concentration basis reported in Tai and Tagawa. The generated reactions are shown on the Reactions sheet:

The Tai/Tagawa model presumes that all condensation reactions (model generated reactions 1-4 above) have the same rate constants. The model also assumes that the hydrolysis reactions (reactions 5-8 above) have the same rate constants. These data are entered on the Rate Constants sheet as shown here:

The catalyst terms refer to the acid catalysis (aminocaproic acid, ACA, and acid end groups, T-COOH, both contain an acid end). The Assign Rate Constants sheet is used to link each set of rate constants to an appropriate set of reactions:

Rate constants 1, 2, and 3 are assigned to condensation reactions (e.g., the reactions between acid and amine end groups). Rate constants 4, 5, and 6 are assigned to the hydrolysis reactions (e.g., the reactions in which water attacks a polymer chain). The step-growth model does not automatically generate ring opening or ring addition reactions. These must be defined as user-specified reactions on the User Reactions sheet. The forward and reverse components of these reactions are entered separately, as shown here:

236


The model includes reactions for cyclic monomer (CL) and cyclic dimer (CD). The formation of cyclic trimer and higher cyclics is considered negligible and is not considered in the present model. On the User Reactions sheet, reactions 1 and 2 refer to ring opening of caprolactam and its reverse reaction (ring closure). The forward reaction is set first order with respect to caprolactam and water. The reverse reaction is set first order with respect to aminocaproic acid (the model assumes that the concentration of linear dimer is equal to the concentration of aminocaproic acid—this assumption is used to keep the model consistent with the Tai/Tagawa model, which also assumes [P 1] = [P2] = [P3].) Reaction 3 refers to ring addition of caprolacatam to polymer amine end groups. Reaction 4 is the corresponding cyclodepolymerization reaction. The forward reaction is presumed to be first order with respect to caprolactam and amine end groups. The reverse reaction is assumed to be first order with respect to amine end groups. Reaction 5 refers to ring addition of caprolacatam to monomeric aminocaproic aminocaproic acid. Reaction 6 is the corresponding cyclodepolymerization reaction. The forward reaction is presumed to be first order with respect to caprolactam and aminocaproic acid. The reverse reaction is assumed to be first order with respect to aminocaproic acid (once again, the model assumes that the concentration of linear dimer is equal to the concentration of aminocaproic acid). Reactions 7-12 (which apply to cyclic dimer) are analogous to reactions 1-6 (which apply to cyclic monomer). The rate constants for the user specified reactions are specified on the User Rate Constants sheet:

In total, twenty-four sets of rate constants are specified. These rate constants are linked to the reactions on the Assign User Rate Constants sheet, shown here:

238


Process Studies In order to determine the effect of feed flow rate on caprolactam conversion, degree of polymerization, and extraction value, a sensitivity study is carried out with the feed mass flow as the varied parameter. The sampled parameters are the polymer properties, the component fractions used to determine conversion, and the flowrates.

Input Summary The input language summary for this example is shown here: TITLE 'CAPROLACTAM POLYMERIZATION' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='l/hr' PRESSURE=atm TEMPERATURE=C TIME=hr & VOLUME=l MOLE-ENTHALP='kcal/mol' MOLE-ENTROPY='kcal/mol-K' INVERSE-TIME='1/hr' LN-INV-TIME='ln(1/hr)' PDROP='N/sqm' DEF-STREAMS CONVEN ALL DIAGNOSTICS HISTORY SIM-LEVEL=3 PROP-LEVEL=3 RUN-CONTROL MAX-TIME=15000.0 DESCRIPTION "THIS IS A MODEL OF A NYLON-6 PROCESS. " DATABANKS POLYMER / PURE12 / SEGMENT / INORGANIC / NOASPENPCD PROP-SOURCES POLYMER / PURE12 SOLIDS / INORGANIC

/ AQUEOUS

/ SEGMENT

/ SOLIDS

/ AQUEOUS

/

&

COMPONENTS H2O H2O / CL C6H11NO / ACA C6H11NO / CD C6H11NO / NYLON NYLON6 / T-NH2 C6H12NO-E-1 / T-COOH C6H12NO2-E-1 / B-ACA C6H11NO-R-1 FLOWSHEET BLOCK BLOCK BLOCK BLOCK

STAGE1 IN=FEED RECYCLE R2-VAP OUT=R1-OLIGO R1VAP DISTIL IN=R1VAP OUT=COND RECYCLE STAGE2 IN=R1-OLIGO OUT=R2-VAP R2-OLIGO PLUG IN=R2-OLIGO OUT=POLYMER

PROPERTIES POLYNRTL PROP-DATA MW IN-UNITS SI PROP-LIST MW PVAL ACA 131.174760

&

&

PVAL CD 226.318960 PROP-DATA PLXANT-1 IN-UNITS SI PRESSURE=atm PDROP='N/sqm' PROP-LIST PLXANT PVAL ACA -40.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PVAL CD -40.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1000.0 PROP-DATA NRTL-1 IN-UNITS ENG PROP-LIST NRTL BPVAL H2O CL -4.01840 1634.2356470 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 BPVAL CL H2O -.79760 3537.9406520 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 BPVAL H2O ACA -4.01840 1634.2356470 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 BPVAL ACA H2O -.79760 3537.9406520 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 BPVAL H2O CD -4.01840 1634.2356470 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 BPVAL CD H2O -.79760 3537.9406520 .30 0.0 0.0 0.0 & 105.80000320 508.99999990 POLYMERS SEGMENTS T-NH2 END / T-COOH END / B-ACA REPEAT POLYMERS NYLON ATTRIBUTES NYLON SFLOW ZMOM FMOM DPN MWN EFRAC SFRAC STREAM FEED SUBSTREAM MIXED TEMP=260.0 PRES=1.0 MASS-FLOW=3600. NPHASE=1 PHASE=L MASS-FRAC H2O .010 / CL .990

&

STREAM RECYCLE SUBSTREAM MIXED TEMP=116.523631 PRES=1 MASS-FLOW=145.425133 MASS-FRAC H2O 0.217256374 / CL 0.782743626 BLOCK DISTIL RADFRAC PARAM NSTAGE=20 COL-CONFIG CONDENSER=TOTAL REBOILER=NONE FEEDS R1VAP 21 PRODUCTS COND 1 L / RECYCLE 20 L P-SPEC 1 1.0 COL-SPECS MOLE-RR=3.0 BLOCK STAGE1 RCSTR DESCRIPTION "CAPROLACTAM POLYMERIZATION" PARAM VOL=10. TEMP=260.0 PRES=1.0 NPHASE=2 PHASE=L PHASE-VOL=6.75 MB-MAXIT=350 MB-TOL=.000010 & DAMP-FAC=.10 PRODUCTS R1-OLIGO L / R1VAP V MOLE-FLOW MIXED CL 6.5 MOLE-FLOW MIXED H2O 1.6 MOLE-FLOW MIXED NYLON 10.5 MOLE-FLOW MIXED ACA 0.01 BLOCK-OPTION FREE-WATER=NO

240

&


REACTIONS RXN-IDS=NYLON BLOCK STAGE2 RCSTR PARAM VOL=10. TEMP=260.0 PRES=1.20 NPHASE=2 MB-MAXIT=350 MB-TOL=.000010 DAMP-FAC=.10 PRODUCTS R2-VAP V / R2-OLIGO L MOLE-FLOW MIXED H2O .00280 MOLE-FLOW MIXED CL .03850 MOLE-FLOW MIXED ACA .00001610 MOLE-FLOW MIXED NYLON .137780 BLOCK-OPTION FREE-WATER=NO REACTIONS RXN-IDS=NYLON

&

BLOCK PLUG RPLUG PARAM TYPE=T-SPEC LENGTH=20. DIAM=1.85 PHASE=L PRES=1.40 NPOINT=20 INT-TOL=.000010 FLASH=YES COOLANT TOL=.000010 T-SPEC 0.0 260.0 / 1.0 260.0 REACTIONS RXN-IDS=NYLON

&

EO-CONV-OPTI SENSITIVITY FLOW PARAM BASE-CASE=LAST DEFINE R1CL MASS-FLOW STREAM=R1-OLIGO SUBSTREAM=MIXED & COMPONENT=CL DEFINE R1NYL MASS-FLOW STREAM=R1-OLIGO SUBSTREAM=MIXED & COMPONENT=NYLON DEFINE R1MN COMP-ATTR-VAR STREAM=R1-OLIGO SUBSTREAM=MIXED & COMPONENT=NYLON ATTRIBUTE=MWN ELEMENT=1 DEFINE R2CL MASS-FLOW STREAM=R2-OLIGO SUBSTREAM=MIXED & COMPONENT=CL DEFINE R2NYL MASS-FLOW STREAM=R2-OLIGO SUBSTREAM=MIXED & COMPONENT=NYLON DEFINE R2MN COMP-ATTR-VAR STREAM=R2-OLIGO SUBSTREAM=MIXED & COMPONENT=NYLON ATTRIBUTE=MWN ELEMENT=1 DEFINE R3MN COMP-ATTR-VAR STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=NYLON ATTRIBUTE=MWN ELEMENT=1 DEFINE R3CL MASS-FLOW STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=CL DEFINE R3NYL MASS-FLOW STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=NYLON DEFINE R3ACA MASS-FLOW STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=ACA DEFINE R3CD MASS-FLOW STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=CD DEFINE R3F STREAM-VAR STREAM=FEED SUBSTREAM=MIXED & VARIABLE=MASS-FLOW DEFINE R1COND MASS-FLOW STREAM=COND SUBSTREAM=MIXED & COMPONENT=H2O DEFINE R3FW MASS-FRAC STREAM=R2-OLIGO SUBSTREAM=MIXED & COMPONENT=H2O DEFINE R2COND MASS-FLOW STREAM=R2-VAP SUBSTREAM=MIXED & COMPONENT=H2O DEFINE R2FW MASS-FRAC STREAM=R1-OLIGO SUBSTREAM=MIXED & COMPONENT=H2O DEFINE FWF MASS-FRAC STREAM=FEED SUBSTREAM=MIXED &

F

COMPONENT=H2O DEFINE R3H2O MASS-FLOW STREAM=POLYMER SUBSTREAM=MIXED & COMPONENT=H2O EV = (R3CL+R3H2O+R3ACA+R3CD)/R3F*1 (R3CL+R3H2O+R3ACA+R3CD)/R3F*100 00 TABULATE 1 "R1NYL/(R1NYL+R1CL)" COL-LABEL="R1-CONV" TABULATE 2 "R2NYL/(R2NYL+R2CL)" COL-LABEL="R2-CONV" TABULATE 3 "R3NYL/(R3NYL+R3CL)" COL-LABEL="R3-CONV" TABULATE 4 "R1MN" COL-LABEL="R1-MN" TABULATE 5 "R2MN" COL-LABEL="R2-MN" TABULATE 6 "R3MN" COL-LABEL="R3-MN" TABULATE 7 "EV" COL-LABEL="EXTRACTE" TABULATE 8 "FWF*100." COL-LABEL="FEED WF" "WATER" "PERCENT." TABULATE 9 "R2FW*100." COL-LABEL="R2OUT" "WATER" "PERCENT." TABULATE 10 "R3FW*100." COL-LABEL="R3WF" "WATER" "PERCENT." TABULATE 11 "R1COND" COL-LABEL="R1-COND" TABULATE 12 "R2COND" COL-LABEL="R2-COND" TABULATE 13 "R3CD" TABULATE 14 "R3CL" VARY STREAM-VAR STREAM=FEED SUBSTREAM=MIXED VARIABLE=MASS-FLOW RANGE LOWER="1200" UPPER="9000" INCR="600"

CONV-OPTIONS PARAM TRACE=.00010 CHECKSEQ=YES WEGSTEIN MAXIT=50 STREAM-REPOR NOZEROFLOW MOLEFLOW MASSFLOW MASSFRAC REACTIONS NYLON STEP-GROWTH REAC-TYPES REARRANGE=NO EXCHANGE=NO OPTIONS CONC-BASIS="MOL/KG" SPECIES POLYMER=NYLON REAC-GROUP TNH2 E-GRP / TCOOH N-GRP / BCAP EN-GRP SG-RATE-CON 1 PRE-EXP=1.8940E+10 ACT-ENERGY=23.2710 SG-RATE-CON 2 CAT-SPEC=ACA PRE-EXP=1.2110E+10 & ACT-ENERGY=20.670 SG-RATE-CON 3 CAT-SPEC=T-COOH PRE-EXP=1.2110E+10 & ACT-ENERGY=20.670 SG-RATE-CON 4 PRE-EXP=1.1780E+10 ACT-ENERGY=29.21680 SG-RATE-CON 5 CAT-SPEC=ACA PRE-EXP=7.5340E+09 & ACT-ENERGY=26.61580 SG-RATE-CON 6 CAT-SPEC=T-COOH PRE-EXP=7.5340E+09 & ACT-ENERGY=26.61580 RXN-SET 1 ELECTRO-GRP=TNH2 NUCLEO-GRP=TCOOH RC-SETS=1 2 3 RXN-SET 2 NUCLEOPHILE=H2O RC-SETS=4 5 6 SPECIES-GRP T-NH2 TNH2 1 / T-NH2 BCAP 1 / T-COOH TCOOH & 1 / T-COOH BCAP 1 / ACA TNH2 1 / ACA TCOOH 1 / & ACA BCAP 1 / B-ACA BCAP 1 / H2O TNH2 1 / H2O TCOOH 1 STOIC 1 CL -1.0 / H2O -1.0 / ACA 1.0 STOIC 2 ACA -1.0 / CL 1.0 / H2O 1.0 STOIC 3 CL -1.0 / B-ACA 1.0 STOIC 4 B-ACA -1.0 / CL 1.0 STOIC 5 CL -1.0 / ACA -1.0 / T-NH2 1.0 / T-COOH 1.0 STOIC 6 T-NH2 -1.0 / T-COOH -1.0 / ACA 1.0 / CL 1.0 STOIC 7 CD -1.0 / H2O -1.0 / T-NH2 1.0 / T-COOH 1.0 STOIC 8 T-NH2 -1.0 / T-COOH -1.0 / CD 1.0 / H2O 1.0 STOIC 9 CD -1.0 / B-ACA 2.0 STOIC 10 B-ACA -2.0 / CD 1.0

242


STOIC 11 CD -1.0 / ACA -1.0 / T-NH2 1.0 / T-COOH 1.0 / B-ACA 1.0 STOIC 12 T-NH2 -1.0 / T-COOH -1.0 / B-ACA -1.0 / ACA & 1.0 / CD 1.0 RATE-CON 1 598740.0 19.880 0.0 RATE-CON 2 4.3080E+07 18.8060 0.0 CATALYST=ACA RATE-CON 3 4.3080E+07 18.8060 0.0 CATALYST=T-COOH RATE-CON 4 3.1660E+07 17.9620 0.0 RATE-CON 5 2.2780E+09 16.8880 0.0 CATALYST=ACA RATE-CON 6 2.2780E+09 16.8880 0.0 CATALYST=T-COOH RATE-CON 7 2.8560E+09 22.8450 0.0 RATE-CON 8 1.6400E+10 20.1070 0.0 CATALYST=ACA RATE-CON 9 1.6400E+10 20.1070 0.0 CATALYST=T-COOH RATE-CON 10 9.4200E+10 26.8880 0.0 RATE-CON 11 5.4000E+11 24.1510 0.0 CATALYST=ACA RATE-CON 12 5.4000E+11 24.1510 0.0 CATALYST=T-COOH RATE-CON 13 8.5800E+11 42.0 0.0 RATE-CON 14 2.3300E+12 37.40 0.0 CATALYST=ACA RATE-CON 15 2.3300E+12 37.40 0.0 CATALYST=T-COOH RATE-CON 16 1.2800E+15 51.60 0.0 RATE-CON 17 3.4800E+15 47.0 0.0 CATALYST=ACA RATE-CON 18 3.4800E+15 47.0 0.0 CATALYST=T-COOH RATE-CON 19 2.5700E+08 21.30 0.0 RATE-CON 20 3.0110E+09 20.40 0.0 CATALYST=ACA RATE-CON 21 3.0110E+09 20.40 0.0 CATALYST=T-COOH RATE-CON 22 1.9200E+08 24.50 0.0 RATE-CON 23 2.2458E+09 23.5690 0.0 CATALYST=ACA RATE-CON 24 2.2458E+09 23.5690 0.0 CATALYST=T-COOH POWLAW-EXP 1 CL 1.0 / H2O 1.0 POWLAW-EXP 2 ACA 1.0 POWLAW-EXP 3 CL 1.0 / T-NH2 1.0 POWLAW-EXP 4 T-NH2 1.0 POWLAW-EXP 5 CL 1.0 / ACA 1.0 POWLAW-EXP 6 ACA 1.0 POWLAW-EXP 7 CD 1.0 / H2O 1.0 POWLAW-EXP 8 ACA 1.0 POWLAW-EXP 9 CD 1.0 / T-NH2 1.0 POWLAW-EXP 10 T-NH2 1.0 POWLAW-EXP 11 CD 1.0 / ACA 1.0 POWLAW-EXP 12 ACA 1.0 ASSIGN-URC 1 RC-SETS=1 2 3 ASSIGN-URC 2 RC-SETS=4 5 6 ASSIGN-URC 3 RC-SETS=7 8 9 ASSIGN-URC 4 RC-SETS=10 11 12 ASSIGN-URC 5 RC-SETS=7 8 9 ASSIGN-URC 6 RC-SETS=10 11 12 ASSIGN-URC 7 RC-SETS=13 14 15 ASSIGN-URC 8 RC-SETS=16 17 18 ASSIGN-URC 9 RC-SETS=19 20 21 ASSIGN-URC 10 RC-SETS=22 23 24 ASSIGN-URC 11 RC-SETS=19 20 21 ASSIGN-URC 12 RC-SETS=22 23 24

Selected Simulation Results The following three figures show the effect of feed flow rate on caprolactam conversion, number-average number-average molecular weight (Mn), and extraction value. Increasing the feed to CSTR-1 decreases the total residence time. Therefore, caprolactam conversion decreases in all of the reactors as shown here: 2 9 . 0 9 . 0 8 n 8 . o i 0 s r e v 6 n 8 . o 0 C L C 4 8 . 0

Stage 1

2 8 . 0 1000

Stage 2 Product

2000

3000

4000 5000 6000 Feed Flow Rate, kg/hr

7000

8000

9000

As flow rate increases, the reactor residence time decreases. The average molecular weight of the polymer at each point in the reactor decreases with the residence time. 0 0 0 ) 2 n 2 M ( t h 0 g 0 i e 0 0 W 2 r a l u c 0 e 0 l o 0 8 M e 1 g a r e v 0 A 0 r 0 e 6 b 1 m u N 1000

Stage 1 Stage 2 Product

2000

3000

4000 5000 6000 Feed Flow Rate, kg/hr

7000

8000

9000

Extraction value (EV) is the sum of the extractables from the polymer. These include unreacted caprolactam, aminocaproic acid, cyclic dimer and water. Extraction value is an indicator of the cost of recycling unreacted monomers. Since conversion decreases with an increase in feed flow rate, EV increases. Therefore, one has to find the optimum feed flow rate that increases the production rate while minimizing the percentage of extractables. The effect of feed flow rate on extraction value is shown here:

244


5 2 . 9 s e l b a 2 t . c 9 a r t x E t n e c r 5 e 1 . P 9

1000 2000 3000 4000 5000 6000 7000 8000 9000 Feed Flow Rate, kg/hr

Simulation Stream Summary The summary report for the flowsheet streams in the base case simulation is shown here: STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR H2O CL ACA CD NYLON COMPONENTS: KG/HR H2O CL ACA CD NYLON COMPONENTS: MASS FRAC H2O CL ACA CD NYLON TOTAL FLOW: KMOL/HR KG/HR L/HR

COND DISTIL ----

FEED ---STAGE1

POLYMER PLUG ----

R1-OLIGO STAGE1 STAGE2

R1VAP STAGE1 DISTIL

LIQUID

LIQUID

LIQUID

LIQUID

VAPOR

1.4138 0.0 0.0 0.0 0.0

1.9983 31.4954 0.0 0.0 0.0

0.4199 2.5820 9.3725-04 0.1336 28.6715

0.4074 4.3448 1.3062-03 9.1208-02 26.9949

3.1676 1.0059 0.0 0.0 0.0

25.4704 0.0 0.0 0.0 0.0

36.0000 3564.0000 0.0 0.0 0.0

7.5647 292.1742 0.1229 30.2269 3244.4503

7.3389 491.6540 0.1713 20.6420 3054.7330

57.0643 113.8274 0.0 0.0 0.0

1.0000 0.0 0.0 0.0 0.0

1.0000-02 0.9900 0.0 0.0 0.0

2.1163-03 8.1738-02 3.4394-05 8.4562-03 0.9077

2.0531-03 0.1375 4.7932-05 5.7747-03 0.8546

0.3339 0.6661 0.0 0.0 0.0

1.4138 25.4704 26.4708

33.4937 3600.0000 4128.3629

31.8078 3574.5391 4076.1662

31.8396 3574.5392 4082.4945

4.1735 170.8917 1.8156+05

STATE VARIABLES: TEMP C 100.0178 260.0000 260.0000 260.0000 PRES ATM 1.0000 1.0000 1.4000 1.0000 VFRAC 0.0 0.0 0.0 0.0 LFRAC 1.0000 1.0000 1.0000 1.0000 SFRAC 0.0 0.0 0.0 0.0 ENTHALPY: KCAL/MOL -66.9095 -60.9440 -33.5836 -35.2702 J/KG -1.5550+07 -2.3740+06 -1.2512+06 -1.3153+06 WATT -1.1002+05 -2.3740+06 -1.2423+06 -1.3060+06 ENTROPY: KCAL/MOL-K -3.4934-02 -0.1333 -0.1249 -0.1257 J/KG-K -8118.6922 -5190.5311 -4652.7256 -4689.3221 DENSITY: KMOL/CUM 53.4106 8.1131 7.8034 7.7991 KG/CUM 962.2076 872.0164 876.9365 875.5772 AVG MW 18.0153 107.4830 112.3792 112.2671 COMPONENT ATTRIBUTES: NYLON SFLOW T-NH2 MISSING MISSING 0.1637 0.1758 T-COOH MISSING MISSING 0.1637 0.1758 B-ACA MISSING MISSING 28.3181 26.6153 ZMOM ZMOM MISSING MISSING 0.1637 0.1758 FMOM FMOM MISSING MISSING 28.6454 26.9669 DPN DPN MISSING MISSING 175.0405 153.3812 MWN MWN MISSING MISSING 1.9826+04 1.7375+04 EFRAC T-NH2 MISSING MISSING 0.5000 0.5000 T-COOH MISSING MISSING 0.5000 0.5000 SFRAC T-NH2 MISSING MISSING 5.7130-03 6.5197-03 T-COOH MISSING MISSING 5.7130-03 6.5197-03 B-ACA MISSING MISSING 0.9886 0.9870

260.0000 1.0000 1.0000 0.0 0.0 -54.0250 -5.5240+06 -2.6222+05 -3.1706-02 -3241.8948 2.2987-02 0.9413 40.9473 MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING

R2-OLIGO R2-VAP RECYCLE ----------------------STREAM ID FROM : TO :

MAX CONV. ERROR: SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR H2O CL ACA CD NYLON COMPONENTS: KG/HR H2O

246

R2-OLIGO STAGE2 PLUG

0.0 LIQUID

R2-VAP STAGE2 STAGE1

0.0

RECYCLE DISTIL STAGE1

-8.2523-05

MISSING

LIQUID

0.4130 2.6584 9.4242-04 0.1232 28.6169

0.0 0.0 0.0 0.0 0.0

1.7537 1.0060 0.0 0.0 0.0

7.4394

0.0

31.5941


CL 300.8186 ACA 0.1236 CD 27.8857 NYLON 3238.2718 COMPONENTS: MASS FRAC H2O 2.0812-03 CL 8.4156-02 ACA 3.4584-05 CD 7.8012-03 NYLON 0.9059 TOTAL FLOW: KMOL/HR 31.8123 KG/HR 3574.5391 L/HR 4077.5613 STATE VARIABLES: TEMP C 260.0000 PRES ATM 1.2000 VFRAC 0.0 LFRAC 1.0000 SFRAC 0.0 ENTHALPY: KCAL/MOL -33.6554 J/KG -1.2540+06 WATT -1.2452+06 ENTROPY: KCAL/MOL-K -0.1250 J/KG-K -4656.2050 DENSITY: KMOL/CUM 7.8018 KG/CUM 876.6365 AVG MW 112.3633 COMPONENT ATTRIBUTES: NYLON SFLOW T-NH2 0.1706 T-COOH 0.1706 B-ACA 28.2485 ZMOM ZMOM 0.1706 FMOM FMOM 28.5897 DPN DPN 167.5852 MWN MWN 1.8982+04 EFRAC T-NH2 0.5000 T-COOH 0.5000 SFRAC T-NH2 5.9671-03 T-COOH 5.9671-03 B-ACA 0.9881

0.0 0.0 0.0 0.0 MISSING MISSING MISSING MISSING MISSING 0.0 0.0 0.0 MISSING MISSING MISSING MISSING MISSING

113.8368 0.0 0.0 0.0 0.2172 0.7828 0.0 0.0 0.0 2.7597 145.4309 142.7860 116.5236 1.0000 0.0 1.0000 0.0

MISSING -67.3955 MISSING -5.3545+06 MISSING -2.1631+05 MISSING -7.7525-02 MISSING -6159.2868 MISSING MISSING MISSING

19.3277 1018.5232 52.6976

0.0 0.0 0.0

0.0 0.0 0.0

0.0

0.0

MISSING

MISSING

MISSING

MISSING

MISSING

MISSING

MISSING MISSING

MISSING MISSING



References Gupta, A. K., & Gandhi, G andhi, K. S. (1985). Modeling of Backmixing in Continuous Polymerization of Caprolactam in VK Column Reactors. Ind. Eng. Chem. Product Research and Development , 24, 24, p. 327. Hotyzer P. J., Hoogschagen, J., & Van Krevelen, D. W. (1965). Optimization of Caprolactam Polymerization. Chem. Eng. Sci., Sci., 20, 20, p. 247. Reimschuessel H. K. (1977). Nylon 6: Chemistry and Mechanisms. J. Mechanisms. J. Polymerization Sci.: Macromolecular Reviews, Reviews , 12, 12, p. 65. Tai K., Arai, Y., & Tagawa, T. (1982). The Simulation of Hydrolytic Polymerization of Caprolactam in Various Reactors. J. Appl. Polymer Sci Sci ., ., 22, 22, p. 731. Tai K., & Tagawa, Tagawa, T. (1983). Simulation of Hydrolytic Polymerization of Caprolactam in Various Reactors. A review on recent advances in reaction engineering of polymerization. Industrial & Engineering Chemistry Research, 22, 22, p. 192.

248


C10 Methyl Methacrylate Polymerization in Ethyl Acetate

The methyl methacrylate polymerization in ethyl acetate model illustrates the use of Aspen Polymers Plus to model a solution polymerization process for methyl methacrylate in ethyl acetate. Among the studies carried out using this model are the effect of initiator concentration and reactor temperature on molecular weight and conversion.

About This Process Polymethyl methacrylate is part of the polyacrylic group of polymers. It is used in the manufacture of lenses or other clear coverings and is also known under the trade names plexiglass, lucite, acrylate, etc. This methyl methacrylate polymerization is carried out in a free-radical solution process. Solution polymerization is used when both the monomer and the initiator are soluble in the solvent. Typically, solution processes result in low viscosity, provide good mixing, and improve heat transfer limitations, while improving temperature control and reducing gel effect. On the other hand, these processes result in lower reaction rate and in lower polymer molecular weight due to chain transfer to solvents. Furthermore, solvent removal can be costly. The flowsheet for this process consists of a batch reactor followed by a devolatizer for solvent removal. The reactor feed contains methyl methacrylate dissolved in ethyl acetate, with AIBN as the initiator. The reactor operates under constant temperature and pressure.

Process Definition The batch reactor is modeled using RBatch, and the devolitizer using Flash2:


Name

Databank

Description

Methyl-methacrylate

MMA

PURE12

Monomer

Ethyl-acetate

EA

PURE12

Solvent

Polymethylmethacrylate

PMMA

POLYMER

Polymer

MMA-R

SEGMENT

Methyl methacrylate segment

AIBN

AIBN

PURE12

Initiator (Mw=164.210) (Mw=164.210)

Physical Properties


Feed Streams Temperature (°C)

0

Pressure (atm)

1

Methylmethacrylate (kg/h)

100 (25 wt%)

Ethyl Acetate (kg/hr)

300 (75 wt%)

Initiator (kg/hr)

3.757

The feed is sent to RBATCH as a batch feed

250

Kinetics

FREE-RAD model


RBATCH

FLASH

Temperature (°C)

50

60

Pressure

1 atm

100 mmHg

C10 Methyl Methacrylate Polymeriza Polymerization tion in Ethyl Acetate

Reactors / Kinetics The kinetic parameters of solution polymerization of methyl methacrylate are available in literature (Ellis et al., 1988). The reactions used in this model and their rate constant parameters are: Description

k0

Ea (J/Kmol) Efficiency

Initiator decomposition decomposition

1.2525E14

1.228E8

0.5 0.5

Chain initiation

4.92E5

1.824E7

---

Propagation

4.92E5

1.82E7

---


7.177E9

7.513E7

---

Chain transfer to solvent

4.673E8

6.57E7

---

Termination by disproportionation disproportionation

9.8E7

2.937E6

---

Because of the presence of a large amount of solvents (75% by weight), geleffect is not significant and is therefore not considered. At high monomer conversion, gel-effect can be used to improve the agreement between the model predictions and experimental data. In the batch reactor two two reactor stop conditions conditions are provided: stop after 5 hours of reaction time, or stop at 99% monomer conversion (corresponds to PMMA mass fraction of 0.2452). The first option is used to obtain conversion and polymer molecular weight information as a function of time. The second option is used to examine the effect of temperature and initiator concentration of PMMA properties at a given conversion.

Process Studies The PMMA process model is used to examine process variables such as conversion number and weight average molecular weight as a function of time, at three different reactor temperatures. The model predictions are compared against literature data (Ellis, 1990). The model is also used to study the effects of initiator concentration and polymerization temperature temperature on the following: reaction time to reach reach 99% monomer conversion, peak heat load, number and weight average molecular weight. A sensitivity study is also performed to show the percent solids as a function of outlet temperature.

Input Summary The input language summary for this example is shown here: DYNAPLUS DPLUS RESULTS=ON TITLE 'Polymerization of MMA' IN-UNITS MET

DEF-STREAMS CONVEN ALL DESCRIPTION " Polymerization of methyl methacrylate(MMA) in a batch. reactor " DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS MMA C5H8O2-D3 / EA C4H8O2-3 / AIBN C5H8O2-D3 / PMMA PMMA / MMA-R C5H8O2-R-1 FLOWSHEET BLOCK FLASH IN=PROD OUT=FV FL BLOCK RBATCH IN=FEED OUT=PROD PROPERTIES POLYNRTL PROP-DATA MW IN-UNITS MET PROP-LIST MW PVAL AIBN 164.210 POLYMERS SEGMENTS MMA-R REPEAT POLYMERS PMMA ATTRIBUTES PMMA SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM & FMOM SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW & LEFRAC LPFRAC DISTRIBUTION PMMA CHAIN-SIZE CLD NPOINTS=100 UPPER=10000. PROP-SET PS-1 MASSFRAC SUBSTREAM=MIXED COMPS=PMMA MMA EA PHASE=L

&

PROP-SET PS-2 MOLECONC UNITS='kmol/cum' SUBSTREAM=MIXED COMPS=AIBN PHASE=L

&

PROP-SET PS-3 MOLECONC UNITS='kmol/cum' SUBSTREAM=MIXED COMPS=AIBN MMA PHASE=L

&

STREAM FEED SUBSTREAM MIXED TEMP=273.0 PRES=1.0 MASS-FLOW MMA 100.0 / EA 300.0 / AIBN 3.7570 BLOCK FLASH FLASH2 PARAM TEMP=333.150 PRES=.131578947 BLOCK RBATCH RBATCH PARAM TYPE=T-SPEC PRINT-TIME=.50 CYCLE-TIME=1.0 & MAX-TIME=100.0 MAX-NPOINT=202 PRES=1.0 TEMP=323.0 STOP 1 REACTOR MASS-FRAC .24520 FROM-BELOW COMP=PMMA &

252


SSID=MIXED PROP-REACTOR PS-1 REACTIONS RXN-IDS=REAC-1 EO-CONV-OPTI CALCULATOR F-1 DEFINE FTEMP STREAM-VAR STREAM=FEED SUBSTREAM=MIXED & VARIABLE=TEMP DEFINE RTEMP BLOCK-VAR BLOCK=RBATCH VARIABLE=TEMP & SENTENCE=PARAM F FTEMP = RTEMP EXECUTE BEFORE BLOCK RBATCH CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW PROPERTIES=PS-2 PS-3 REACTIONS REAC-1 FREE-RAD IN-UNITS SI PARAM SPECIES INITIATOR=AIBN MONOMER=MMA SOLVENT=EA POLYMER=PMMA MON-RSEG MMA MMA-R INIT-DEC AIBN 1.2525E+14 1.2280E+08 EFFIC=.50 CHAIN-INI MMA 492000.0 1.8240E+07 PROPAGATION MMA MMA 492000.0 1.8240E+07 CHAT-MON MMA MMA 7.1770E+09 7.5130E+07 CHAT-SOL MMA EA 4.6730E+08 6.5700E+07 TERM-DIS MMA MMA 9.8000E+07 2937000.0

Selected Simulation Results The mass flow of PMMA versus the time is shown here: 100 T = 323K T = 333K

80

) g K ( s 60 s a M A 40 M M P

T = 338K T = 343K

20 0 0

1

2

3 Time (Hr) (Hr)

4

5

The mass flow of PMMA is equivalent to monomer conversion versus time since the feed rate is 100 kg/hr. As shown, at high temperature, over 90% of monomers are converted within 5 hours, while at low temperature (50°C), only 40% of monomers are converted. These results are within 1% deviation from literature simulation results (Ellis, 1988). The PMMA number-average molecular weight versus time at different reacting temperatures is shown here: 70000 60000 T = 323K

50000

T = 333K

N W40000 M A M30000 M P

T = 338K T = 343K

20000 10000 0 0

1

2

3

4

5

Time Time (Hr)

As temperature increases, the number-average molecular weight of PMMA decreases. The Aspen Polymers Plus predictions agree closely with literature simulation. At high monomer conversion, the addition of gel-effect is needed to improve agreement between the predictions and experimental data. The reaction time, in hours, needed to reach 99% monomer conversion at various temperatures and initiator charges is shown here: 50 45

AIB N Charge Cha rge = 3

n o 40 i s r e 35 v n 30 o C 25 % 9 20 9 r o 15 f e m10 i T 5

AIB N Charge Cha rge = 3.757 AIB N Charge Cha rge = 6 AIB N Charge Cha rge = 10

0 320

325

330

335

340

345

350

355

Tempe rature (K) (K)

254


The different curves correspond to different initiator charges. At a particular initiator charge, the reaction time decreases with temperature. At constant temperature, the reaction time decreases as the initiator charge (and hence concentration) increases. Therefore, higher reaction temperature and initiator concentration allow faster monomer conversion. The following two figures show the molecular weight dependency of temperature and initiator charge. In general, both the number and weightaverage molecular weight increase as temperature increases and initiator charge decreases. The ratio of Mw and Mn gives the polydispersity index (PDI). MWn at 99% conversion versus temperature and initiator charge is shown here: 25000 AIB N Charge Cha rge = 3 n 20000 o i s r e v n 15000 o C % 9 10000 9 t a N W 5000 M

AIB N Charge Cha rge = 3.757 AIB N Charge Cha rge = 6 AIB N Charge Cha rge = 10

0 320

325

330

335 340 Temperature (K)

345

350

355

MWw at 99% conversion versus temperature and initiator charge is shown here:

90000 AIB N Charge Cha rge = 3

80000

AIB N Charge = 3.757

n 70000 o i s r e 60000 v n o 50000 C %40000 9 9 t 30000 a W20000 W M

AIB N Charge Cha rge = 6 AIB N Charge = 10

10000 0 320

325

330

335 340 Tempe rature (K) (K)

345

350

355

The PMMA polydispersity index is shown here: 4.4 AIB N Charge Cha rge = 3

4.2 n o 4 i s r e 3.8 v n o C3.6 % 9 3.4 9 t a I 3.2 D P

AIB N Charge = 3.757 AIB N Charge Cha rge = 6 AIB N Charge = 10

3

2.8 320

325

330

335 340 Tempe rature (K) (K)

345

350

355

As shown, at a given conversion, PDI decreases as temperature increases, and increases as initiator charge increases. The maximum in the reactor instantaneous heat duty as a function of reactor temperature and initiator concentration is shown here:

256


Temperature (K) 32 0

325

3 30

335

340

3 45

350

3 55

0 -500

) s / l a c -1000 ( y t u D-1500 . x a M

-2000

AIB N Charge Cha rge = 3 AIB N Charge Cha rge = 3.757 AIB N Charge Cha rge = 6 AIB N Charge Cha rge = 10

-2500 For the case of a reactor with specified temperature, the maximum heat duty occurs immediately after reactions start. In the the simulation results presented presented above, the heat duty reported at 0.5 hr is taken to be the maximum. This is the second profile point computed when the time interval is set to 0.5 hour. Technically it is not the true peak heat duty. Smaller time intervals between profile points may be used to obtain more accurate peak heat duty. The results of the sensitivity study on the flash block are shown here:

0.96 n 0.94 o i t c 0.92 a r F s 0.9 s a M A0.88 M M P 0.86

0.84 3 20

32 5

330

335

340

345

35 0

35 5

Flash Flash Te mperature (K) As the flash temperature varies, the polymer content in the liquid output stream changes accordingly. No binary parameters are used in the polymer NRTL model. If liquid-vapor equilibria data is available, the binary parameters may be fitted to allow more accurate predictions.

References Ellis, M. F., Taylor, T. W. X., Gonzalez, V., & Jensen, K. F. (1988). Estimation of the Molecular Weight Distribution in Batch Polymerization. AIChE J ., ., 34, 34, p. 1341. Ellis, M. F. (1990). Online Control and Estimation of the Molecular Weight Distribution in a Batch Polymerization Reactor . PhD Thesis, Dept. of Chem. Engr., Univ. of Minn. Grulke, E. A. (1994). Polymer Process Engineering. New Jersey: Prentice Hall. Tulig, T. J., & Tirrell, M. (1981). Toward a Molecular Theory of the Trommsdorff Effect. Macromolecules, Macromolecules, 14, 14, p. 1501.

258


C11 Polypropylene Gas Phase Polymerization Processes

The polypropylene gas-phase polymerization process model illustrates the use of Aspen Polymers Plus to model a gas-phase UNIPOL process for propylene homopolymerization using a four site Ziegler-Natta kinetic model. The atactic content, melt flow ratio and molecular weight averages are some of the polymer product properties and attributes predicted by the simulation.

About This Process There are three types of processes commonly employed for the manufacture of isotactic polypropylene (PP) homo- and co-polymers. These include liquid slurry processes, bulk or liquid pool processes, and gas-phase processes. The following table provides basic information on these processes and lists some of the companies that have commercialized the process technology: Process Reactor

Diluent / Solvent

Catalyst

Tacticity (%)

Temp. ( C)

Press. (atm)

Residence Time (hr)

Company

Bulk (Liquid Pool)

Liquid monomer

Supported Ti Catalyst

up tp 99%

60-80

30-40

1-2

Himont

CSTR

Liquid monomer

Unsupported or supported Ti catalyst

up to 98%

60-75

30-40

2.0

Dart El Paso Montedison Sumitomo

Diluent Slurry

CSTR

n-hexane, n-heptane


up to 98%

60-80

15-20

3-4

Amoco Montedison

Gas

Fluidized bed

N2

Supported Ti catalyst

up to 98%

60-80

20

3-5

Sumitomo Union Carbide

Vertical stirred bed

---


up to 98%

70-90

20

4

BASF ICI USI

Horizontal

---

Unsupported

up to

70-90

20

4

Amoco

Loop reactor

Mitsui

Process Reactor compartmented stirred bed

Diluent / Solvent

Catalyst

Tacticity (%)

or supported Ti catalyst

98%

Temp. ( C)

Press. (atm)

Residence Time (hr)

Company

All of these processes use a Ziegler-Natta catalyst (usually TiCl 4) in either a supported or non-supported form together with an alkylaluminum or aluminum chlorides (for example, triethyl-aluminum) cocatalyst. Liquid slurry processes use an inert hydrocarbon diluent as the slurry medium or polymer suspending agent. This process is still the most widely used process for PP manufacture. Continuous stirred tank reactors are usually used and several reactors may be used in series or parallel arrangements. Typical reactor operating conditions and residence times were listed in the previous table. Bulk or liquid pool processes are a special case of the slurry processes. They use liquid propylene instead of an inert diluent as the slurry medium to suspend the polymer. The increased monomer concentration leads to higher polymerization rates in liquid pool processes relative to slurry processes. Hence, shorter reactor residence times may be employed. Several reactor types, including stirred autoclaves with evaporative cooling and loop reactors, are used to attain good heat transfer rates. In gas-phase processes, gaseous propylene is contacted with solid catalyst/polymer powder in fluidized bed or mechanically stirred bed reactors. The reactor temperature is usually controlled by evaporative cooling of liquid propylene. The unreacted monomer is removed from the reactor headspace, condensed or cooled and recirculated to the reactor. Aspen Polymers Plus can be used with Aspen Plus for the simulation of steady-state operation of any of the PP processes described above. Aspen Polymers Plus can be used with Aspen Custom Modeler when dynamic simulation or detailed modeling of the flow patterns or heat transfer within the reactor is desired. This example describes a steady-state simulation of a gas-phase UNIPOL flowsheet.

Process Definition An Aspen Polymers Plus model is developed to simulate a PP gas-phase UNIPOL flowsheet. The flowsheet includes the fluidized bed reactor, the gas recycle/cooling loop, discharge, and purge units:

260

C11 Polypropylene Gas Phase Polymeriza Polymerization tion Processes

The fluidized bed reactor is modeled using the CSTR reactor in Aspen Plus with two phases: a gas phase and a polymer phase. The POLYPCSF (PCSAFT) (PCSAFT) thermodynamic model is used to relate the gas phase monomer, hydrogen, etc. composition to their concentrations in the polymer phase. The multisite Ziegler-Natta kinetic model is used to describe the polymerization reactions in the polymer phase. The kinetic model calculates the reaction rates for the components and polymer attributes at each site type. User-Property models are used to calculate polymer properties such as melt flow index (MFI), isotactic index (or atactic fraction) from the polymer attributes.

Process Conditions The process conditions are: Components Titanium Tetrachloride (CAT)

Catalyst

Triethyl-Aluminium (COCAT)

Co-catalyst

Propylene (C3=)

Monomer

Propane (C3)

Inert

Polypropylene (PP)

Polymer

H2


N2

Inert

Water (H2O)

Cooling water

Propylene Segment (C3-SEG)

Polymer segment

Component

Flow rate (Kg/Hr)

Catalyst

3.0

Co-catalyst

10.0

Propylene

17462.0

Propane

162.29

H2

1.38

N2

1.45

Operating Conditions Temperature

69 °C

Pressure drop

200 KPa

Total volume

90 m3

Polymer Phase volume

60 m3

The reactor feed also includes a large recycle stream with partially condensed propylene and other volatile components. An Aspen Plus CSTR reactor model is used to represent the fluid-bed reactor. The reactor is considered to have two phases; a vapor phase and a polymer phase.

262


Physical Property Models and Data The polymer PCSAFT equation of state model (POLYPCSF) is used as the physical property method.

Reactors / Kinetics The Ziegler-Natta kinetic scheme used in the model includes spontaneous site activation, chain initiation, propagation, chain transfer to hydrogen, monomer and co-catalyst, and spontaneous site deactivation. Four site types are used in this example to represent the broad molecular weight distributions that are typically observed for Ziegler-Natta polymers. The actual number of site types necessary to model a given catalyst-polymerization system is determined by deconvolution of the polymer molecular weight distribution curve obtained from a GPC analysis. The rate parameters used in the model are: Reaction

Site ID

Comp. ID 1

ACT-SPON

1

ACT-SPON

Comp. ID 2

Preexp

Activation Energy (kcal/mol)

Order

Ref. Temp. ( C)

TICL4

0.0013

7.64

1

69

2

TICL4

0.0013

7.64

1

69

ACT-SPON

3

TICL4

0.0013

7.64

1

69

ACT-SPON

4

TICL4

0.0013

7.64

1

69

CHAIN-INI

1

C3H6

108.85

7.2

1

69

CHAIN-INI

2

C3H6

24.5

7.2

1

69

CHAIN-INI

3

C3H6

170.8

7.2

1

69

CHAIN-INI

4

C3H6

60.55

7.2

1

69

PROPAGATION

1

C3H6

C3H6

108.85

7.2

1

69

PROPAGATION

2

C3H6

C3H6

24.5

7.2

1

69

PROPAGATION

3

C3H6

C3H6

170.8

7.2

1

69

PROPAGATION

4

C3H6

C3H6

60.55

7.2

1

69

CHAT-MON

1

C3H6

C3H6

0.012

12.42

1

69

CHAT-MON

2

C3H6

C3H6

0.012

12.42

1

69

CHAT-MON

3

C3H6

C3H6

0.012

12.42

1

69

CHAT-MON

4

C3H6

C3H6

0.012

12.42

1

69

CHAT-COCAT

1

C3H6

TEA

0.12

12

1

69

CHAT-COCAT

2

C3H6

TEA

0.12

12

1

69

CHAT-COCAT

3

C3H6

TEA

0.12

12

1

69

CHAT-COCAT

4

C3H6

TEA

0.12

12

1

69

CHAT-H2

1

C3H6

H2

4.8

10.7

0.5

69

CHAT-H2

2

C3H6

H2

8.88

10.7

0.5

69

CHAT-H2

3

C3H6

H2

2.64

10.7

0.5

69

CHAT-H2

4

C3H6

H2

6.6

10.7

0.5

69

DEACT-SPON

1

0.001

1

1

69

DEACT-SPON

2

0.001

1

1

69

Reaction

Site ID

DEACT-SPON

Comp. ID 1

Comp. ID 2

Preexp

Activation Energy (kcal/mol)

Order

Ref. Temp. ( C)

3

0.001

1

1

69

DEACT-SPON

4

0.001

1

1

69

ATACT-PROP

1

C3H6

C3H6

13.2

7.2

1

69

ATACT-PROP

2

C3H6

C3H6

31.8

7.2

1

69

ATACT-PROP

3

C3H6

C3H6

8

7.2

1

69

ATACT-PROP

4

C3H6

C3H6

18.5

7.2

1

69

The units for the frequency factor and activation energy are in SI units.

Process Studies Input Summary The input language summary for this example is shown here: TITLE 'Ziegler-Natta Gas-Phase Polymerization of Propylene' IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' TEMPERATURE=C TIME=hr DELTA-T=C

&

DEF-STREAMS CONVEN ALL SIM-OPTIONS IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SIM-OPTIONS FLASH-TOL=1E-006

&

SYS-OPTIONS TRACE=YES RUN-CONTROL MAX-TIME=10000.0 DESCRIPTION " Ziegler-Natta gas-Phase polymerization of propylene " DATABANKS PURE12

/ POLYMER

PROP-SOURCES PURE12

/ SEGMENT

/ POLYMER

/ NOASPENPCD

/ SEGMENT

COMPONENTS TICL4 TICL4 / TEA C6H15AL / C3H6 C3H6-2 / C3H8 C3H8 / PP PP / H2 H2 / N2 N2 /

264


H2O H2O / C3H6-R C3H6-R FLOWSHEET BLOCK REACTOR IN=RFEED1 OUT=VAP-A POWDER1 BLOCK FMIX1 IN=CAT COCAT H2FEED C3FEED N2FEED CYCGAGB OUT=RFEED1 BLOCK EXC1 IN=H2O-IN VAP-B OUT=H2O-OUT CYCGAGB BLOCK COMP1 IN=VAP-A OUT=VAP-B BLOCK STRIP1 IN=POWDER1 OUT=GAS1 POWDER2 BLOCK STRIP2 IN=POWDER2 STRIP-N2 OUT=GAS2 PP-PROD

&

PROPERTIES POLYPCSF PROP-DATA PCSAFT IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' TEMPERATURE=C TIME=hr DELTA-T=C PROP-LIST PCSFTM PVAL TICL4 20 PVAL TEA 20 PROP-LIST PCSFTV PVAL C3H6-R 4.1473

&

POLYMERS PARAM NSITES=4 SEGMENTS C3H6-R REPEAT CATALYST TICL4 0.00045 POLYMERS PP ATTRIBUTES PP SFRAC SFLOW DPN DPW PDI MWN MWW ZMOM FMOM & SMOM LDPN LZMOM LFMOM LSFLOW LSFRAC LEFLOW LEFRAC & LPFRAC SSFRAC SSFLOW SDPN SDPW SPDI SMWN SMWW SZMOM & SFMOM SSMOM SPFRAC LSDPN LSZMOM LSFMOM LSSFLOW LSSFRAC & LSEFLOW LSEFRAC LSPFRAC ATFLOW ATFRAC SATFLOW SATFRAC ATTRIBUTES TICL4 CPSFLOW CPSFRAC CVSFLOW CVSFRAC CDSFLOW & CDSFRAC DISTRIBUTION PP STREAM C3FEED IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=3000.0 MASS-FLOW=45000.0 MASS-FRAC C3H6 .9980 / C3H8 .0020 STREAM CAT IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=3000.0 MASS-FLOW=300.0 & NPHASE=1 PHASE=L MASS-FRAC TICL4 .010 / C3H6 .9880 / C3H8 .0020 COMP-ATTR TICL4 CPSFLOW ( 0.0 ) COMP-ATTR TICL4 CPSFRAC ( 1.0 ) COMP-ATTR TICL4 CVSFLOW ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CVSFRAC ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CDSFLOW ( 0.0 ) COMP-ATTR TICL4 CDSFRAC ( 0.0 )

&

&

STREAM COCAT IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=3000.0 MASS-FLOW=10.0 & NPHASE=1 PHASE=L MASS-FRAC TEA 1.0 STREAM CYCGAGB IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=59.0 PRES=3000.0 MASS-FLOW C3H6 800300.0 / C3H8 15930.0 / H2 3998.70 / & N2 5098.0 STREAM H2FEED IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=3000.0 MASS-FLOW=4.0 MASS-FRAC H2 1.0

&

&

&

STREAM H2O-IN IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa SUBSTREAM MIXED TEMP=35.0 PRES=3000.0 MASS-FLOW H2O 847500.0 STREAM N2FEED IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=3000.0 MASS-FLOW=100.0 MASS-FRAC N2 1.0

&

STREAM RFEED1 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa SUBSTREAM MIXED TEMP=65.0 PRES=3000.0 MASS-FLOW TICL4 3.0 / TEA 10.0 / C3H6 817500.0 / C3H8 & 16100.0 / H2 4000.0 / N2 5100.0 COMP-ATTR TICL4 CPSFLOW ( 0.0 ) COMP-ATTR TICL4 CPSFRAC ( 1.0 ) COMP-ATTR TICL4 CVSFLOW ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CVSFRAC ( 0.0 0.0 0.0 0.0 ) COMP-ATTR TICL4 CDSFLOW ( 0.0 ) COMP-ATTR TICL4 CDSFRAC ( 0.0 ) STREAM STRIP-N2 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa SUBSTREAM MIXED TEMP=30.0 PRES=300.0 MASS-FLOW N2 500.0 BLOCK FMIX1 MIXER

266


IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa

&

BLOCK STRIP1 FLASH2 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa PARAM TEMP=65.0 PRES=500.0 BLOCK STRIP2 FLASH2 IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa PARAM TEMP=60.0 PRES=100.0 BLOCK EXC1 MHEATX IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa COLD-SIDE IN=H2O-IN OUT=H2O-OUT TEMP=44. FREE-WATER=NO HOT-SIDE IN=VAP-B OUT=CYCGAGB FREE-WATER=NO

&

BLOCK REACTOR RCSTR IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa USER-VECS NREAL=1 PARAM VOL=90.0 TEMP=69.0 PRES=-200.0 NPHASE=2 PHASE=L & PHASE-VOL=60.0 MB-MAXIT=20 SCALING=COMPONENTS & ALGORITHM=SOLVER PRODUCTS VAP-A V / POWDER1 L MASS-FLOW MIXED PP 15000. CONVERGENCE SOLVER=NEWTON STAB-STRAT=LINE-SEARCH BLOCK-OPTION SIM-LEVEL=8 TERM-LEVEL=7 REACTIONS RXN-IDS=ZN-R1 BLOCK COMP1 COMPR IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & VOLUME-FLOW='cum/hr' PRESSURE=kPa TEMPERATURE=C TIME=hr PDROP=kPa PARAM TYPE=ISENTROPIC DELP=250.0 EO-CONV-OPTI CALCULATOR SETFEED IN-UNITS SI MASS-FLOW='kg/hr' MOLE-FLOW='kmol/hr' & PRESSURE=kPa TEMPERATURE=C TIME=hr DELTA-T=C PDROP=kPa DEFINE RC3E MASS-FLOW STREAM=CYCGAGB SUBSTREAM=MIXED & COMPONENT=C3H6 DEFINE RC3 MASS-FLOW STREAM=CYCGAGB SUBSTREAM=MIXED & COMPONENT=C3H8 DEFINE RH2 MASS-FLOW STREAM=CYCGAGB SUBSTREAM=MIXED & COMPONENT=H2 DEFINE RN2 MASS-FLOW STREAM=CYCGAGB SUBSTREAM=MIXED & COMPONENT=N2 DEFINE FC3E MASS-FLOW STREAM=C3FEED SUBSTREAM=MIXED & COMPONENT=C3H6 DEFINE FC3 MASS-FLOW STREAM=C3FEED SUBSTREAM=MIXED & COMPONENT=C3H8

&

F F F F F F F F F F F F F F

DEFINE FN2 MASS-FLOW STREAM=N2FEED SUBSTREAM=MIXED & COMPONENT=N2 DEFINE FH2 MASS-FLOW STREAM=H2FEED SUBSTREAM=MIXED & COMPONENT=H2 DEFINE FTC3 STREAM-VAR STREAM=C3FEED SUBSTREAM=MIXED VARIABLE=TEMP DEFINE FPC3 STREAM-VAR STREAM=C3FEED SUBSTREAM=MIXED VARIABLE=PRES DEFINE FTH2 STREAM-VAR STREAM=H2FEED SUBSTREAM=MIXED VARIABLE=TEMP DEFINE FPH2 STREAM-VAR STREAM=H2FEED SUBSTREAM=MIXED VARIABLE=PRES DEFINE FTN2 STREAM-VAR STREAM=N2FEED SUBSTREAM=MIXED VARIABLE=TEMP DEFINE FPN2 STREAM-VAR STREAM=N2FEED SUBSTREAM=MIXED VARIABLE=PRES DC3E = 8.172E5 DC3 = 1.61E4 DH2 = 4.0E3 DN2 = 5.1E3 FC3E = DC3E - RC3E FC3 = DC3 - RC3 FH2 = DH2 - RH2 FN2 = DN2 - RN2 FTC3 = 30 FPC3 = 3000 FTH2 = 30 FPH2 = 3000 FTN2 = 30 FPN2 = 3000 READ-VARS RC3E RC3 RH2 RN2 WRITE-VARS FC3E FC3 FN2 FH2 FTC3 FPC3 FTH2 FPH2 FTN2 FPN2

& & & & & &

&

CONV-OPTIONS PARAM CHECKSEQ=NO STREAM-REPOR MOLEFLOW MASSFLOW MASSFRAC REACTIONS ZN-R1 ZIEGLER-NAT IN-UNITS MET DESCRIPTION "Ziegler-Natta Kinetic Scheme" PARAM SPECIES CATALYST=TICL4 COCATALYST=TEA MONOMER=C3H6 & HYDROGEN=H2 POLYMER=PP MON-RSEG C3H6 C3H6-R ACT-SPON 1 TICL4 0.0013 7.64 ORDER=1.0 REF-TEMP=69. ACT-SPON 2 TICL4 0.0013 7.64 ORDER=1.0 REF-TEMP=69. ACT-SPON 3 TICL4 0.0013 7.64 ORDER=1.0 REF-TEMP=69. ACT-SPON 4 TICL4 0.0013 7.64 ORDER=1.0 REF-TEMP=69. CHAIN-INI 1 C3H6 108.85 7.2 ORDER=1.0 REF-TEMP=69. CHAIN-INI 2 C3H6 24.5 7.2 ORDER=1.0 REF-TEMP=69. CHAIN-INI 3 C3H6 170.8 7.2 ORDER=1.0 REF-TEMP=69. CHAIN-INI 4 C3H6 60.55 7.2 ORDER=1.0 REF-TEMP=69. PROPAGATION 1 C3H6 C3H6 108.85 7.2 ORDER=1.0 REF-TEMP=69. PROPAGATION 2 C3H6 C3H6 24.5 7.2 ORDER=1.0 REF-TEMP=69.

268


PROPAGATION 3 PROPAGATION 4 CHAT-MON 1 C3H6 CHAT-MON 2 C3H6 CHAT-MON 3 C3H6 CHAT-MON 4 C3H6 CHAT-COCAT 1 CHAT-COCAT 2 CHAT-COCAT 3 CHAT-COCAT 4 CHAT-H2 1 CHAT-H2 2 CHAT-H2 3 CHAT-H2 4 DEACT-SPON 1 DEACT-SPON 2 DEACT-SPON 3 DEACT-SPON 4 ATACT-PROP 1 ATACT-PROP 2 ATACT-PROP 3 ATACT-PROP 4

C3H6 C3H6 170.8 7.2 ORDER=1.0 REF-TEMP=69. C3H6 C3H6 60.55 7.2 ORDER=1.0 REF-TEMP=69. C3H6 0.012 12.42 ORDER=1.0 REF-TEMP=69. C3H6 0.012 12.42 ORDER=1.0 REF-TEMP=69. C3H6 0.012 12.42 ORDER=1.0 REF-TEMP=69. C3H6 0.012 12.42 ORDER=1.0 REF-TEMP=69. C3H6 TEA 0.12 12. ORDER=1.0 REF-TEMP=69. C3H6 TEA 0.12 12. ORDER=1.0 REF-TEMP=69. C3H6 TEA 0.12 12. ORDER=1.0 REF-TEMP=69. C3H6 TEA 0.12 12. ORDER=1.0 REF-TEMP=69. C3H6 H2 4.8 10.7 ORDER=.50 REF-TEMP=69. C3H6 H2 8.88 10.7 ORDER=.50 REF-TEMP=69. C3H6 H2 2.64 10.7 ORDER=.50 REF-TEMP=69. C3H6 H2 6.6 10.7 ORDER=.50 REF-TEMP=69. 0.001 1. ORDER=1.0 REF-TEMP=69. 0.001 1. ORDER=1.0 REF-TEMP=69. 0.001 1. ORDER=1.0 REF-TEMP=69. 0.001 1. ORDER=1.0 REF-TEMP=69. C3H6 C3H6 13.2 7.2 REF-TEMP=69. C3H6 C3H6 31.8 7.2 REF-TEMP=69. C3H6 C3H6 8. 7.2 REF-TEMP=69. C3H6 C3H6 18.5 7.2 REF-TEMP=69.

Selected Simulation Results The results include component mass f lowrates, thermophysical thermophysical information (temperature, pressure, enthalpy, etc.) and catalyst and polymer attributes. The polymer attributes are reported for the composite polymer and the polymer made at each site type. The polymer atactic fraction and melt flow ratio are reported at the end of the stream report.

Simulation Stream Summary The stream summary results for selected streams are shown here: C3FEED CAT COCAT CYCGAGB GAS1 ----------------------------STREAM ID FROM : TO : SUBSTREAM: MIXED PHASE: COMPONENTS: KMOL/HR TICL4 TEA C3H6 C3H8 PP H2 N2 H2O

C3FEED ---FMIX1

CAT ---FMIX1

COCAT ---FMIX1

CYCGAGB EXC1 FMIX1

GAS1 STRIP1 ----

LIQUID

LIQUID

LIQUID

MIXED

VAPOR

0.0 8.7591-02 0.0 0.0 0.0 0.0 0.0 0.0

0.0 0.0 1.8938+04 363.1075 0.0 1983.2900 181.9875 0.0

0.0 0.0 93.4567 1.8182 0.0 0.2875 6.7409-02 0.0

0.0 0.0 481.8696 2.0007 0.0 0.0 0.0 0.0

1.5815-02 0.0 7.0436 1.3607-02 0.0 0.0 0.0 0.0

COMPONENTS: KG/HR TICL4 0.0 3.0000 0.0 0.0 0.0 TEA 0.0 0.0 10.0000 0.0 0.0 C3H6 2.0277+04 296.4000 0.0 7.9692+05 3932.7172 C3H8 88.2250 0.6000 0.0 1.6012+04 80.1756 PP 0.0 0.0 0.0 0.0 0.0 H2 0.0 0.0 0.0 3998.0747 0.5796 N2 0.0 0.0 0.0 5098.1034 1.8883 H2O 0.0 0.0 0.0 0.0 0.0 COMPONENTS: MASS FRAC TICL4 0.0 1.0000-02 0.0 0.0 0.0 TEA 0.0 0.0 1.0000 0.0 0.0 C3H6 0.9957 0.9880 0.0 0.9695 0.9794 C3H8 4.3321-03 2.0000-03 0.0 1.9478-02 1.9967-02 PP 0.0 0.0 0.0 0.0 0.0 H2 0.0 0.0 0.0 4.8637-03 1.4433-04 N2 0.0 0.0 0.0 6.2018-03 4.7028-04 H2O 0.0 0.0 0.0 0.0 0.0 TOTAL FLOW: KMOL/HR 483.8703 7.0730 8.7591-02 2.1466+04 95.6298 KG/HR 2.0366+04 300.0000 10.0000 8.2203+05 4015.3608 CUM/SEC 1.1203-02 1.6602-04 1.5554-05 3.6892 0.1422 STATE VARIABLES: TEMP C 30.0000 30.0000 30.0000 60.4597 65.0000 PRES N/SQM 3.0000+06 3.0000+06 3.0000+06 3.0500+06 5.0000+05 VFRAC 0.0 0.0 0.0 0.9501 1.0000 LFRAC 1.0000 1.0000 1.0000 4.9906-02 0.0 SFRAC 0.0 0.0 0.0 0.0 0.0 ENTHALPY: J/KMOL 4.0704+06 1.9775+06 2.3114+08 1.4874+07 1.9601+07 J/KG 9.6710+04 4.6624+04 2.0246+06 3.8841+05 4.6682+05 WATT 5.4710+05 3885.3294 5623.7639 8.8690+07 5.2069+05 ENTROPY: J/KMOL-K -2.1278+05 -2.1338+05 -1.6270+06 -1.5446+05 -1.4871+05 J/KG-K -5055.4997 -5030.7049 -1.4252+04 -4033.4369 -3541.6804 DENSITY: KMOL/CUM 11.9974 11.8340 1.5643 1.6163 0.1868 KG/CUM 504.9576 501.9360 178.5894 61.8946 7.8448 AVG MW 42.0890 42.4146 114.1666 38.2939 41.9886 COMPONENT ATTRIBUTES: TICL4 CPSFLOW CPSFLOW MISSING 1.3500-03 MISSING MISSING MISSING CPSFRAC CPSFRAC MISSING 1.0000 MISSING MISSING MISSING CVSFLOW SITE_1 MISSING 0.0 MISSING MISSING MISSING SITE_2 MISSING 0.0 MISSING MISSING MISSING SITE_3 MISSING 0.0 MISSING MISSING MISSING SITE_4 MISSING 0.0 MISSING MISSING MISSING CVSFRAC SITE_1 MISSING 0.0 MISSING MISSING MISSING SITE_2 MISSING 0.0 MISSING MISSING MISSING SITE_3 MISSING 0.0 MISSING MISSING MISSING SITE_4 MISSING 0.0 MISSING MISSING MISSING CDSFLOW CDSFLOW MISSING 0.0 MISSING MISSING MISSING CDSFRAC

270


CDSFRAC

MISSING

0.0

MISSING

MISSING

MISSING

H2O-IN ---EXC1

H2O-OUT EXC1 ----

N2FEED ---FMIX1

LIQUID

VAPOR

GAS2 H2FEED H2O-IN H2O-OUT N2FEED --------------------------------STREAM ID FROM : TO :

GAS2 STRIP2 ----

H2FEED ---FMIX1

SUBSTREAM: MIXED PHASE: VAPOR VAPOR LIQUID COMPONENTS: KMOL/HR TICL4 0.0 0.0 0.0 TEA 0.0 0.0 0.0 C3H6 9.3084 0.0 0.0 C3H8 0.1833 0.0 0.0 PP 0.0 0.0 0.0 H2 4.1346-04 0.9551 0.0 N2 17.8059 0.0 0.0 H2O 0.0 0.0 4.7043+04 COMPONENTS: KG/HR TICL4 0.0 0.0 0.0 TEA 0.0 0.0 0.0 C3H6 391.7052 0.0 0.0 C3H8 8.0813 0.0 0.0 PP 0.0 0.0 0.0 H2 8.3348-04 1.9253 0.0 N2 498.8065 0.0 0.0 H2O 0.0 0.0 8.4750+05 COMPONENTS: MASS FRAC TICL4 0.0 0.0 0.0 TEA 0.0 0.0 0.0 C3H6 0.4359 0.0 0.0 C3H8 8.9932-03 0.0 0.0 PP 0.0 0.0 0.0 H2 9.2754-07 1.0000 0.0 N2 0.5551 0.0 0.0 H2O 0.0 0.0 1.0000 TOTAL FLOW: KMOL/HR 27.2981 0.9551 4.7043+04 KG/HR 898.5939 1.9253 8.4750+05 CUM/SEC 0.2096 2.2702-04 0.2391 STATE VARIABLES: TEMP C 60.0000 30.0000 35.0000 PRES N/SQM 1.0000+05 3.0000+06 3.0000+06 VFRAC 1.0000 1.0000 0.0 LFRAC 0.0 0.0 1.0000 SFRAC 0.0 0.0 0.0 ENTHALPY: J/KMOL 7.4863+06 1.8496+05 -2.8683+08 J/KG 2.2742+05 9.1750+04 -1.5921+07 WATT 5.6767+04 49.0676 -3.7481+09 ENTROPY: J/KMOL-K -3.9913+04 -2.7710+04 -1.6580+05 J/KG-K -1212.4972 -1.3746+04 -9203.5570 DENSITY: KMOL/CUM 3.6182-02 1.1686 54.6449

0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.7043+04

0.0 0.0 0.0 0.0 0.0 0.0 6.7702-02 0.0

0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.4750+05

0.0 0.0 0.0 0.0 0.0 0.0 1.8966 0.0

0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0000

0.0 0.0 0.0 0.0 0.0 0.0 1.0000 0.0

4.7043+04 8.4750+05 0.2412

6.7702-02 1.8966 1.5692-05

44.0000 3.0000+06 0.0 1.0000 0.0

30.0000 3.0000+06 1.0000 0.0 0.0

-2.8602+08 -4.6019+04 -1.5877+07 -1642.7572 -3.7376+09 -0.8654 -1.6323+05 -2.8251+04 -9060.3732 -1008.4905 54.1828

1.1985

KG/CUM AVG MW

1.1910 32.9179

2.3557 2.0159

984.4427 18.0153

976.1187 18.0153

PP-PROD STRIP2 ----

RFEED1 FMIX1 REACTOR

33.5736 28.0135

POWDER1 POWDER2 PP-PROD RFEED1 STRIP-N2 --------------------------------------STREAM ID FROM : TO :

POWDER1 REACTOR STRIP1

MAX CONV. ERROR: 0.0 SUBSTREAM: MIXED PHASE: LIQUID COMPONENTS: KMOL/HR TICL4 1.5815-02 TEA 8.7165-02 C3H6 103.4097 C3H8 2.0143 PP 385.5366 H2 0.2879 N2 6.7702-02 H2O 0.0 COMPONENTS: KG/HR TICL4 3.0000 TEA 9.9514 C3H6 4351.5476 C3H8 88.8250 PP 1.6224+04 H2 0.5804 N2 1.8966 H2O 0.0 COMPONENTS: MASS FRAC TICL4 1.4507-04 TEA 4.8122-04 C3H6 0.2104 C3H8 4.2953-03 PP 0.7845 H2 2.8066-05 N2 9.1713-05 H2O 0.0 TOTAL FLOW: KMOL/HR 491.4193 KG/HR 2.0679+04 CUM/SEC 7.9047-03 STATE VARIABLES: TEMP C 69.0000 PRES N/SQM 2.8000+06 VFRAC 0.0 LFRAC 1.0000 SFRAC 0.0 ENTHALPY: J/KMOL -6.3962+07 J/KG -1.5200+06 WATT -8.7311+06 ENTROPY: J/KMOL-K -2.9520+05

272

POWDER2 STRIP1 STRIP2 0.0 LIQUID

0.0 LIQUID

-3.4466-06 MIXED

STRIP-N2 ---STRIP2 0.0 VAPOR

1.5815-02 8.7165-02 9.9530 0.1961 385.5366 4.1377-04 2.9362-04 0.0

1.5815-02 8.7165-02 0.6446 1.2883-02 385.5366 3.1201-07 4.2896-02 0.0

1.5815-02 8.7591-02 1.9427+04 365.1218 0.0 1984.2451 182.0552 0.0

0.0 0.0 0.0 0.0 0.0 0.0 17.8486 0.0

3.0000 9.9514 418.8304 8.6494 1.6224+04 8.3411-04 8.2254-03 0.0

3.0000 9.9514 27.1252 0.5681 1.6224+04 6.2897-07 1.2017 0.0

3.0000 10.0000 8.1750+05 1.6101+04 0.0 4000.0000 5100.0000 0.0

0.0 0.0 0.0 0.0 0.0 0.0 500.0000 0.0

1.8003-04 5.9717-04 2.5134-02 5.1904-04 0.9736 5.0054-08 4.9360-07 0.0

1.8444-04 6.1181-04 1.6677-03 3.4926-05 0.9974 3.8669-11 7.3879-05 0.0

3.5599-06 1.1866-05 0.9701 1.9106-02 0.0 4.7466-03 6.0519-03 0.0

0.0 0.0 0.0 0.0 0.0 0.0 1.0000 0.0

395.7895 1.6664+04 5.7517-03

386.3400 1.6265+04 5.5169-03

2.1958+04 8.4271+05 3.7533

17.8486 500.0000 4.1618-02

65.0000 5.0000+05 0.0 1.0000 0.0

60.0000 1.0000+05 0.0 1.0000 0.0

59.6604 3.0000+06 0.9225 7.7502-02 0.0

30.0000 3.0000+05 1.0000 0.0 0.0

-8.1459+07 -8.4134+07 -1.9347+06 -1.9984+06 -8.9557+06 -9.0289+06

1.4632+07 3.8126+05 8.9247+07

1.2595+05 4495.9140 624.4325

-3.2452+05 -3.3033+05 -1.5564+05 -8597.9812


J/KG-K -7015.1378 -7707.6093 -7846.1345 -4055.5540 DENSITY: KMOL/CUM 17.2690 19.1147 19.4524 1.6251 KG/CUM 726.6967 804.7944 818.9732 62.3680 AVG MW 42.0810 42.1034 42.1015 38.3775 COMPONENT ATTRIBUTES: TICL4 CPSFLOW CPSFLOW 3.3358-05 3.3358-05 3.3358-05 1.3500-03 CPSFRAC CPSFRAC 2.4709-02 2.4709-02 2.4709-02 1.0000 CVSFLOW SITE_1 4.6857-08 4.6857-08 4.6857-08 0.0 SITE_2 3.8123-07 3.8123-07 3.8123-07 0.0 SITE_3 1.6479-08 1.6479-08 1.6479-08 0.0 SITE_4 1.1552-07 1.1552-07 1.1552-07 0.0 CVSFRAC SITE_1 3.4709-05 3.4709-05 3.4709-05 0.0 SITE_2 2.8239-04 2.8239-04 2.8239-04 0.0 SITE_3 1.2206-05 1.2206-05 1.2206-05 0.0 SITE_4 8.5569-05 8.5569-05 8.5569-05 0.0 CDSFLOW CDSFLOW 1.1634-03 1.1634-03 1.1634-03 0.0 CDSFRAC CDSFRAC 0.8618 0.8618 0.8618 0.0 PP SFRAC C3H6-R 1.0000 1.0000 1.0000 0.0 SFLOW C3H6-R 385.5035 385.5035 385.5035 MISSING DPN DPN 535.8466 535.8466 535.8466 0.0 DPW DPW 2435.3752 2435.3752 2435.3752 0.0 PDI PDI 4.5449 4.5449 4.5449 0.0 MWN MWN 2.2549+04 2.2549+04 2.2549+04 0.0 MWW MWW 1.0248+05 1.0248+05 1.0248+05 MISSING ZMOM ZMOM 0.7194 0.7194 0.7194 MISSING FMOM FMOM 385.5035 385.5035 385.5035 MISSING SMOM SMOM 9.3885+05 9.3885+05 9.3885+05 MISSING LDPN LDPN 791.0950 791.0950 791.0950 0.0 LZMOM LZMOM 1.5271-04 1.5271-04 1.5271-04 MISSING LFMOM LFMOM 0.1208 0.1208 0.1208 MISSING LSFLOW C3H6-R 0.1208 0.1208 0.1208 0.0 LSFRAC C3H6-R 1.0000 1.0000 1.0000 MISSING LEFLOW C3H6-R 1.5271-04 1.5271-04 1.5271-04 MISSING LEFRAC

-306.9230 0.1191 3.3372 28.0135 MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING

C3H6-R LPFRAC LPFRAC SSFRAC C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 SSFLOW C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 SDPN SITE_1 SITE_2 SITE_3 SITE_4 SDPW SITE_1 SITE_2 SITE_3 SITE_4 SPDI SITE_1 SITE_2 SITE_3 SITE_4 SMWN SITE_1 SITE_2 SITE_3 SITE_4 SMWW SITE_1 SITE_2 SITE_3 SITE_4 SZMOM SITE_1 SITE_2 SITE_3 SITE_4 SFMOM SITE_1 SITE_2 SITE_3 SITE_4 SSMOM SITE_1 SITE_2 SITE_3 SITE_4 SPFRAC SITE_1 SITE_2 SITE_3

274

1.0000

1.0000

1.0000

MISSING

MISSING

2.1226-04

2.1226-04

2.1226-04

MISSING

MISSING

1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000

MISSING 0.0 MISSING 0.0


115.0567 25.9067 180.5319 64.0082

115.0567 25.9067 180.5319 64.0082

115.0567 25.9067 180.5319 64.0082

MISSING MISSING MISSING 0.0


750.2711 95.8851 1998.9729 311.3573

750.2711 95.8851 1998.9729 311.3573

750.2711 95.8851 1998.9729 311.3573

MISSING 0.0 MISSING MISSING


1499.5423 190.7701 3996.9458 621.7145

1499.5423 190.7701 3996.9458 621.7145

1499.5423 190.7701 3996.9458 621.7145



1.9987 1.9896 1.9995 1.9968

1.9987 1.9896 1.9995 1.9968

1.9987 1.9896 1.9995 1.9968

3.1572+04 4034.9046 8.4118+04 1.3102+04

3.1572+04 4034.9046 8.4118+04 1.3102+04

3.1572+04 4034.9046 8.4118+04 1.3102+04



6.3102+04 8027.7285 1.6819+05 2.6162+04

6.3102+04 8027.7285 1.6819+05 2.6162+04

6.3102+04 8027.7285 1.6819+05 2.6162+04



0.1534 0.2702 9.0312-02 0.2056

0.1534 0.2702 9.0312-02 0.2056

0.1534 0.2702 9.0312-02 0.2056



115.0567 25.9067 180.5319 64.0082

115.0567 25.9067 180.5319 64.0082

115.0567 25.9067 180.5319 64.0082



1.7253+05 4942.2257 7.2158+05 3.9795+04

1.7253+05 4942.2257 7.2158+05 3.9795+04

1.7253+05 4942.2257 7.2158+05 3.9795+04



0.2985 6.7202-02 0.4683

0.2985 6.7202-02 0.4683

0.2985 6.7202-02 0.4683

0.0 0.0 0.0 0.0

0.0 0.0 0.0




SITE_4 LSDPN SITE_1 SITE_2 SITE_3 SITE_4 LSZMOM SITE_1 SITE_2 SITE_3 SITE_4 LSFMOM SITE_1 SITE_2 SITE_3 SITE_4 LSSFLOW C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 LSSFRAC C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 LSEFLOW C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 LSEFRAC C3H6-R_1 C3H6-R_2 C3H6-R_3 C3H6-R_4 LSPFRAC SITE_1 SITE_2 SITE_3 SITE_4 ATFLOW ATFLOW ATFRAC ATFRAC SATFLOW SITE_1 SITE_2 SITE_3 SITE_4 SATFRAC SITE_1 SITE_2 SITE_3 SITE_4

0.1660

0.1660

0.1660

0.0

750.2711 95.8851 1998.9729 311.3573

750.2711 95.8851 1998.9729 311.3573

750.2711 95.8851 1998.9729 311.3573

3.8270-05 3.7936-05 3.8300-05 3.8201-05

3.8270-05 3.7936-05 3.8300-05 3.8201-05

3.8270-05 3.7936-05 3.8300-05 3.8201-05

2.8713-02 3.6375-03 7.6562-02 1.1894-02

2.8713-02 3.6375-03 7.6562-02 1.1894-02

2.8713-02 3.6375-03 7.6562-02 1.1894-02



2.8713-02 3.6375-03 7.6562-02 1.1894-02

2.8713-02 3.6375-03 7.6562-02 1.1894-02

2.8713-02 3.6375-03 7.6562-02 1.1894-02



1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000



3.8270-05 3.7936-05 3.8300-05 3.8201-05

3.8270-05 3.7936-05 3.8300-05 3.8201-05

3.8270-05 3.7936-05 3.8300-05 3.8201-05



1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000

1.0000 1.0000 1.0000 1.0000

2.4955-04 1.4041-04 4.2409-04 1.8582-04

2.4955-04 1.4041-04 4.2409-04 1.8582-04

2.4955-04 1.4041-04 4.2409-04 1.8582-04

75.1546

75.1546

75.1546

0.0

MISSING

0.1950

0.1950

0.1950

0.0

MISSING

13.9341 33.2752 8.4516 19.4938

13.9341 33.2752 8.4516 19.4938

13.9341 33.2752 8.4516 19.4938

0.0 0.0 MISSING MISSING


0.1211 1.2844 4.6815-02 0.3046

0.1211 1.2844 4.6815-02 0.3046

0.1211 1.2844 4.6815-02 0.3046



MISSING MISSING MISSING MISSING 0.0 0.0 0.0 0.0

0.0 0.0 0.0 0.0 MISSING MISSING MISSING MISSING

MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING

MISSING MISSING MISSING MISSING MISSING MISSING MISSING MISSING

VAP-A VAP-B ----------STREAM ID FROM : TO :

VAP-A REACTOR COMP1

VAP-B COMP1 EXC1

SUBSTREAM: MIXED PHASE: VAPOR VAPOR COMPONENTS: KMOL/HR TICL4 0.0 0.0 TEA 0.0 0.0 C3H6 1.8938+04 1.8938+04 C3H8 363.1075 363.1075 PP 0.0 0.0 H2 1983.2900 1983.2900 N2 181.9875 181.9875 H2O 0.0 0.0 COMPONENTS: KG/HR TICL4 0.0 0.0 TEA 0.0 0.0 C3H6 7.9692+05 7.9692+05 C3H8 1.6012+04 1.6012+04 PP 0.0 0.0 H2 3998.0747 3998.0747 N2 5098.1034 5098.1034 H2O 0.0 0.0 COMPONENTS: MASS FRAC TICL4 0.0 0.0 TEA 0.0 0.0 C3H6 0.9695 0.9695 C3H8 1.9478-02 1.9478-02 PP 0.0 0.0 H2 4.8637-03 4.8637-03 N2 6.2018-03 6.2018-03 H2O 0.0 0.0 TOTAL FLOW: KMOL/HR 2.1466+04 2.1466+04 KG/HR 8.2203+05 8.2203+05 CUM/SEC 4.6162 4.2580 STATE VARIABLES: TEMP C 69.0000 74.8156 PRES N/SQM 2.8000+06 3.0500+06 VFRAC 1.0000 1.0000 LFRAC 0.0 0.0 SFRAC 0.0 0.0 ENTHALPY: J/KMOL 1.6384+07 1.6641+07 J/KG 4.2784+05 4.3456+05 WATT 9.7693+07 9.9228+07 ENTROPY: J/KMOL-K -1.4945+05 -1.4924+05 J/KG-K -3902.5890 -3897.1742 DENSITY: KMOL/CUM 1.2917 1.4004 KG/CUM 49.4656 53.6268 AVG MW 38.2939 38.2939

276


References Choi, K.-Y., & Ray, W. H. (1985). Recent Developments in Transition Metal Catalyzed Olefin Polymerization - A Survey. II. Propylene Polymerization. JMS-Rev. Macromol. Macromol. Chem. Phys., Phys., C25 (1). (1). Debling, J. A., Han, G. C., Kuijpers, F., VerBurg, J., Zacca, J., & Ray, W.H. (1994). Dynamic Modeling of Product Grade Transitions for Olefin Polymerization Processes. AIChE Processes. AIChE J ., ., 40 (3). Hutchinson, R. A. (1990). Modeling of Particle Growth in Heterogeneous Catalysed Olefin Polymerization. Polymerization. Ph.D. thesis, University of Wisconsin Madison. Kissin, Y. V. (1985). Isospecific Polymerization of Olefins with Heterogeneous Ziegler-Natta Catalysts. Catalysts . New York: Springer-Verlag. Soares, J. B. P., & Hamielec, A. E. (1995). (1995). Deconvolution of Chain-length Chain-length Distributions of Linear Polymers Made by Multiple-site-type Catalysts. Polymer , 36 (11).

Index

2 2,6 dimethyl phenol polymerization 28 property results 35 A Adding See also Entering experimental data 42 flowsheet blocks 6 flowsheet streams 7 property sets 33 property tables 34 prop-sets 57 sensitivity tables 87 simulation descriptions 8 simulation titles 8 Algorithm (fractionation) 94–109 Alias names in Predici 112 Ammonium persulfate 172 Antisolvents 69 Aromatic polyether 28 Aspen Polymers Plus calculating end-use properties 82–91 characterizing components 10 creating flowsheets 6 creating new runs 5 creating simulation models 5–27 defining unit operation blocks 16 examining simulation results 18 expanded polystyrene suspension polymerization 147–56 fitting kinetic parameters 51–68 fractionation 69–81 fractionation algorithm 94–109 HDPE modeling 192–210

278

LDPE modeling 211–29 linking with Excel 26 methyl methacrylate polymerization 248–58 nylon 6 caprolactam polymerization 229–48 plotting distributions 22 polyproplylene gas phase polymerization 259–77 polystyrene modeling 121–32 polystyrene with styrene monomer distillation 133–46 Predici interface 110–19 predicting physical properties 28–38 regressing property parameters 39–50 running simulations 18 saving runs 27 simulation examples 5–91 specifying components 9 specifying feed streams 12 specifying global options 7 specifying kinetics 13 specifying physical properties 11 styrene butadiene emulsion polymerization 171–83 styrene butadiene ionic polymerization 184–91 styrene ethyl acrylate copolymerization 157–71 tracking distributions 11 user model library 92 user models 92–119 AspenTech support 3 AspenTech Support Center 3 Azo-bis-isobutyronitrile 157 B Benzene 69, 133 Benzoyl peroxide 149 Binary interaction parameters 39 Blocks distribution data 22 entering conditions 60 entering convergence 60 entering convergence sequence 64 entering mixer specifications 17 improving convergence 17 in flowsheets 6 overriding global values 17

Index

renaming 7 specifying 16 Blowing agents 148 Building process flowsheets 6 simulation models 5–27 Bulk polymerization 121–32 Butadiene styrene emulsion copolymerization 171–83 styrene ionic polymerization 184–91 C Calculating end-use properties 82–91 properties 76 Caprolactam conversion 244 example flowsheet 231 example input summary 239 example kinetics 233 example process conditions 232 example process studies 239 example results 244 example stream summary 245 extraction value results 244 Mn results 244 nylon 6 polymerization 229–48 step-growth polymerization 230 Catalysts for Ziegler-Natta 192 Chain length distribution results (Predici interface) 115 results (SBR) 182 Chain transfer agents dodecyl mercaptan 123 ethyl benzene 123, 133 hydrogen 193 tertiary dodecyl mercaptane 172 Characterizing oligomers 10 polymers 10 segments 10 site-based species 10 Components entering pure component parameters 56 mapping from Predici 111, 113 polydispersity 94 predicting properties for 28–38 specifying 9, 30 Convergence

for blocks 60, 64 improving 17 Creating alias file for Predici 112 data sets 61 flowsheets 6 new runs 5 property sets 33 property tables 34 sensitivity tables 87 simulation models 5–27 Crystallinity 33 Custom MWD data 103 Custom property parameters 11 customer support 3 D Data experimental 42 fitting 51–68 regression 39–50 sets 61 Data fit folder 61 specifying regression cases 63 Data regression entering experimental data 42 example for property parameters 39–50 input summary 48 results 65 specifying 61 specifying regression cases 45 Defining mass fraction crystallinity 33 molecular structure 32 oligomers 10 polymers 10 segments 10 site-based species 10 Density predicting 28 results for 2,6 dimethyl phenol 35 Descriptions for simulations 8 Distillation of polystyrene 133–46 Distributions for flowsheets 22 for reactors 22 for streams 22 linking with Excel 26

live plots 23 plots for multiple simulations 24 plotting 22 tables 22 tracking 11 Di-tert-butyl peroxide 123 Dodecyl mercaptan 123 DRS See Data regression E e-bulletins 3 Editing reactions 13 Emulsifiers 172 Emulsion polymerization of styrene butadiene 171–83 End-use properties calculating 82–91 input summary 89 Entering See also Specifying, See also Adding block conditions 60 block convergence 60 block convergence sequence 64 experimental data 42 prop-sets 57 pseudo-components for fractionation model 95 pure component parameters 56 simulation descriptions 8 simulation titles 8 stream conditions 60 EPS See Expanded polystyrene Equations of state fitting parameters 39–50 Sanchez-Lacombe Sanchez-Lacombe 39 Ethanol 69 Ethyl acetate polymerization 248– 58 Ethyl acrylate copolymerization 157–71 Ethyl benzene 123, 133 Ethylene conversion 200 HDPE polymerization 192–210 LDPE polymerization 211–29 Ethylene-polyethylene 39 Examples calculating end-use properties 82–91 expanded polystyrene suspension polymerization 147–56

280

fitting kinetic parameters 51–68 fractionating oligomers 69–81 HDPE polymerization 192–210 LDPE polymerization 211–29 methyl methacrylate polymerization 248–58 nylon 6 caprolactam polymerization 229–48 polymer fractionation algorithm 96, 103 polypropylene gas phase polymerization 259–77 polystyrene bulk polymerization 121–32 polystyrene with styrene monomer distillation 133–46 Predici interface 114 predicting physical properties 28–38 regressing property parameters 39–50 styrene butadiene emulsion copolymerization 171–83 styrene butadiene ionic polymerization 184–91 styrene ethyl acrylate copolymerization 157–71 Excel linking 26 Expanded polystyrene conversion effects 154 example flowsheet 148 example input summary 151 example kinetics 150 example process conditions 149 example process studies 151 example results 154 free-radical polymerization 147 number average molecular weight 155 polymerization 147–56 Experimental data 42 F Feed flow rate effect on ethylene conversion 200 effect on extraction value 244 effect on hydrogen concentration 202 effect on melt index 203 effect on Mn 201, 244

Index

effect on Mw 202 effect on number average molecular weight 128 effect on polydispersity 129, 203 effect on recycle rate 130 effect on styrene conversion 128 effect on weight average molecular weight 129 Feed streams specification 12 Files for polymer fractionation 95 Fitting input summary example 66 kinetic parameters 51–68 mixture parameters 39–50 Flash algorithm (Polymix) 94–109 Flory-Huggins model 69 Flow rate See Feed flow rate Flowsheets creating 6 distribution data 22 placing blocks 6 placing streams 7 renaming blocks 7 renaming streams 7 Fortran subroutines 82, 89 Fractionation example 69–81 input summary 79 Fractionation algorithm creating working directory 95 entering pseudo-components 95 files delivered 95 input summary (PolFrac1) 97 input summary (PolFrac2) 106 installing model 95 opening model 95 phase analysis results 105 PolFrac1 example 96 PolFrac2 example 103 restrictions 94–109 running model 96 separation results 96 stream report (PolFrac1) 100 stream report (PolFrac2) 108 User2 model 94–109 Free-radical polymerization of ethylene 211–29 of expanded polystyrene 147–56 of methyl methacrylate 248–58 of polystyrene 121–32 of styrene butadiene 171–83

of styrene ethyl acrylate 157–71 G Gas-phase polymerization 259–77 Gel effect specification 15 Global options defining unit-sets 8 overriding values 17 report options 9 specifying 7 Group contribution method 28 H HDPE conversion results 200 example flowsheet 193 example input summary 195 example kinetics 194 example model 192–210 example process conditions 193 example process studies 194 example results 200 hydrogen concentration results 202, 204 melt index results 203 Mn results 201 molecular weight distribution 205 Mw results 202 polydispersity results 203 stream summary 205 Heat capacity predicting 28 results for 2,6 dimethyl phenol 35 help desk 3 High-density polyethylene See HDPE Hydrogen 193 Hydrogen concentration 202, 204 I Inhibitors 136 Initiation results 65 thermal 121–32 Initiators ammonium persulfate 172 benzoyl peroxide 149 decomposition vs reactor length 220 methyl peroxide 51

Input summary for data regression example 48 for end-use properties example 89 for expanded polystyrene polymerization 151 for fitting kinetic parameters example 66 for HDPE polymerization 195 for LDPE polymerization 215 for methyl methacrylate polymerization 251 for nylon 6 caprolactam polymerization 239 for oligomer fractionation 79 for polymer fractionation (PolFrac1) 97 for polymer fractionation (PolFrac2) 106 for polypropylene polymerization 264 for polystyrene bulk polymerization 124 for polystyrene with styrene monomer distillation 136 for Predici interface 116 for predicting physical properties example 37 for styrene ethyl acrylate copolymerization 163 for styrene-butadiene emulsion copolymerization 177 for styrene-butadiene ionic polymerization 187 Installing polymer fractionation model 95 user model library 92 Intrinsic viscosity 82 Ionic polymerization of styrene butadiene 184–91 K Kinetics fitting parameters 51–68 modifying reactions 13 specifying 13 specifying gel effect 15 L LDPE coolant temperature profiles 220

282

DPn and DPw vs reactor length 219 ethylene mole fraction 221 example flowsheet 211 example input summary 215 example kinetics 214 example model 211–29 example process conditions 213 example process studies 215 example results 219 free-radical polymerization 211 initiator decomposition vs reactor length 220 reactant temperature profiles 220 reactor temperature profiles 221 stream summary 222 Linking Aspen Polymers Plus with Excel 26 Poymers Plus with Predici 111 Live plots 23 Low-density polyethylene See LDPE M Mapping Predici alias names 113 Predici components 111 Mass fraction crystallinity 33 Melt index 82 Methanol 51 Methyl methacrylate example flowsheet 249 example input summary 251 example kinetics 251 example process conditions 250 example process studies 251 example results 253 flow vs time 253 free-radical polymerization 249 heat duty 256 MWn vs temperature 255 MWw vs temperature 255 number-average number-average molecular weight vs time 254 polydispersity 256 polymerization in ethyl acetate 248–58 reaction time for monomer conversion 254 Methyl peroxide 51 Mixers 17

Index

Mixtures ethylene-polyethylene 39 fitting paramters 39–50 Molecular structure 32 Molecular weight distribution custom data 103 HDPE example 205 in polymer fractionation 94 MWD See Molecular weight distribution N n-hexane 193 n-pentane 148 Nylon 6 caprolactam conversion 244 caprolactam polymerization 229– 48 example flowsheet 231 example input summary 239 example kinetics 233 example process conditions 232 example process studies 239 example results 244 example stream summary 245 extraction value results 244 Mn results 244 step-growth polymerization 230 O OLE linking 26 Oligomers characterizing 10 fractionation example 69–81 Opening Aspen Polymers Plus 5 Aspen Polymers Plus-Predici model 110 fractionation model 95 user models 92 P Parameters binary interaction 39 entering pure component 56 fitting kinetic 51–68 fitting mixture 39–50 Flory-Huggins 69 for polypropylene example 263 regression for styrene ethyl acrylate example 160

specifying 46 specifying binary interaction 75 specifying custom 11 Physical properties example input summary 37 predicting parameters 28–38 regressing parameters 39–50 Plotting distributions 22 live plots 23 manually 25 multiple simulations 24 Poly(phenylene oxide) 28 Polydispersity 69, 94 Polyethylene HDPE polymerization 192–210 intrinsic viscosity 82 LDPE polymerization 211–29 melt index 82 zero-shear viscosity 82 Ziegler-Natta polymerization 192 Polymer fractionation See Fractionation algorithm Polymerization bulk 121–32 emulsion 171–83 gas-phase 259–77 ionic 184–91 of expanded polystyrene 147–56 of HDPE 192–210 of LDPE 211–29 of methyl methacrylate 248–58 of nylon 6 caprolactam 229–48 of polypropylene 259–77 of polystyrene by thermal initiation 121–32 of styrene butadiene 171–83, 184–91 of styrene ethyl acrylate 157–71 solution 192–210, 248–58 suspension 147–56, 259–77 Polymers 2,6 dimethyl phenol 28 aromatic polyether 28 characterizing 10 end-use properties 82–91 ethylene-polyethylene 39 fractionation algorithm 94–109 fractionation example 69–81 poly(phenylene oxide) 28 polystyrene 69 predicting formation during styrene distillation 133–46

specifying mass fraction drystallinity 33 vinyl acetate 51 Polymethyl methacrylate See Methyl methacrylate PolyMix 94 Polyolefin 211 Polyolefins 39 Polypropylene example flowsheet 260 example input summary 264 example kinetics 263 example parameters 263 example process conditions 261 example results 269 example stream summary 269 gas phase polymerization 259– 77 process types 259 Polystyrene See also Expanded polystyrene bulk polymerization 121–32 example flowsheet 121 example input summary 124 example kinetics 123 example process conditions 122 example process studies 124 example results 128 example stream summary 130 fractionation 69 fractionation results 78 free-radical polymerization 121 number average molecular weight 128 polydispersity 69, 129 recycle rate 130 styrene monomer distillation 133–46 thermal initiation example 96 weight average molecular weight 129 Polystyrene distillation example flowsheet 133 example input summary 136 example kinetics 136 example process conditions 134 example results 141 example stream summary 143 inhibitor 136 polymer production results 142 profitability results 142 sensitivity study 141 Predici interface

284

creating alias file 112 example 114 input summary 116 linking with Aspen Polymers Plus 111 mapping component names 113 mapping components 111 opening model 110 running model 114 specifying alias names 112 specifying stream flash 113 stream report 118 using 110–19 Process models See Simulations Propagation results 65 Properties creating property sets 33 creating property tables 34 end-use 82–91 estimating 29 predicting density 28 predicting heat capacity 28 predicting parameters 28–38 predicting thermal conducivity 28 regressing parameters 39–50 specifying calculations 76 specifying custom parameters 11 specifying parameters 46, 75 Property analysis 29 methods 11, 42 parameters 46 sets 33 tables 34 Prop-sets defining 57 fortran subroutines 82 Pseudo-component approach 69 Pseudo-components 95 Pure components parameters 56 predicting properties for 28–38 R Rate constants example input screen 14 for styrene-butadiene emulsion example 175 Reactions modifying 13 rate constants 14 Reactor distribution data 22

Index

Regression cases 45, 63 for styrene ethyl acrylate example 160 Renaming flowsheet blocks 7 flowsheet streams 7 Reports defining options 9 displaying a prop-set 57 Results chain length distribution (Predici interface) 115 chain length distribution (SBR) 182 for expanded polystyrene polymerization 154 for HDPE polymerization 200 for initiation 65 for LDPE polymerization 219 for methyl methacrylate polymerization 253 for nylon 6 caprolactam polymerization 244 for PolFrac1 example 96 for PolFrac2 example 105 for polymer density 35 for polymer heat capacity 35 for polymer thermal conductivity 35 for polypropylene polymerization 269 for polystyrene bulk polymerization 128 for polystyrene with styrene distillation 141 for propagation 65 for styrene ethyl acrylate copolymerization 167 for styrene-butadiene emulsion copolymerization 180 for styrene-butadiene ionic polymerization 189 fractionation of polystyrene 78 plotting 22 reviewing 18 saving 27 Reviewing distribution tables 22 results 18 Run types data regression 40 flowsheet 6

property analysis 29 Running Aspen Polymers Plus 5 fractionation model 96 Polymers-Plus-Predici Polymers-Plus-Predici model 114 S Sanchez-Lacombe 39 Saving 27 SBR See Styrene butadiene Segments characterizing 10 defining molecular structure 32 Sensitivity tables 87 Setup options adding descriptions 8 adding titles 8 defining unit-sets 8 report options 9 specifying 7 specifying time limits 9 Simulations calculating end-use properties 82–91 creating flowsheets 6 creating models 5–27 creating new runs 5 defining report options 9 defining unit-sets 8 entering descriptions for 8 entering time limits 9 entering titles for 8 examples 5–91 expanded polystyrene suspension polymerization 147–56 fitting kinetic parameters 51–68 fractionating oligomers 69–81 HDPE polymerization 192–210 LDPE polymerization 211–29 methyl methacrylate polymerization 248–58 nylon 6 caprolactam polymerization 229–48 plotting multiple 24 polymer fractionation algorithm 94–109 polypropylene gas phase polymerization 259–77 polystyrene bulk polymerization 121–32

polystyrene with styrene monomer distillation 133–46 Predici interface 110–19 predicting physical properties 28–38 regressing property parameters 39–50 results 18 running 18 saving 27 styrene butadiene emulsion copolymerization 171–83 styrene butadiene ionic polymerization 184–91 styrene ethyl acrylate copolymerization 157–71 templates 6 user models 92–119 Site-based species characterization 10 Sodium lauryl sulfate 172 Solution polymerization 192–210, 248–58 Solvents benzene 69, 133 methanol 51 n-hexane 193 toluene 133 Species characterization 10 Specifying See also Entering alias names in Predici 112 binary interaction parameters 75 block conditions 60 block convergence 60 block convergence sequence 64 components 9, 30 custom property parameters 11 data regression 61 data regression cases 45, 63 data sets 61 distributions 11 feed streams 12 gel effect 15 global options 7 kinetics 13 mass fraction crystallinity 33 mixers 17 molecular structure 32 physical property methods 11 property calculations 76 property methods 42 property parameters 46 prop-sets 57

286

pseudo-components for fractionation model 95 report options 9, 57 setup options 7 simulation time limits 9 stream conditions 60 stream flash in Predici interface 113 unit operation blocks 16 unit-sets 8 Starting Aspen Polymers Plus 5 simulation runs 18 user models 92 Step-growth polymerization of caprolactam 229–48 Stream report See Stream summary Stream summary for Predici interface 118 for HDPE polymerization 205 for LDPE polymerization 222 for Nylon 6 caprolactam polymerization 245 for polymer fractionation example (PolFrac1) 100 for polymer fractionation example (PolFrac2) 108 for polypropylene polymerization 269 for polystyrene bulk polymerization 130 for polystyrene with styrene distillation 143 Streams distribution data 22 entering conditions 60 in flowsheets 7 renaming 7 report options 57 specifying 12 specifying flash in Predici interface 113 Styrene bulk polymerization 121–32 butadiene emulsion copolymerization 171–83 butadiene ionic polymerization 184–91 conversion results 128 ethyl acrylate copolymerization 157–71 example flowsheet 121

Index

example input summary 124 example kinetics 123 example process conditions 122 example process studies 124 example results 128 example stream summary 130 free-radical polymerization 121 monomer distillation of polystyrene 133–46 number average molecular weight 128 polydispersity 129 recycle rate 130 suspension polymerization 147 weight average molecular weight 129 Styrene distillation example flowsheet 133 example input summary 136 example kinetics 136 example process conditions 134 example results 141 example stream summary 143 inhibitor 136 polymer production results 142 profitability results 142 sensitivity study 141 Styrene ethyl acrylate copolymerization example 157– 71 example flowsheet 157 example input summary 163 example kinetics 158 example process conditions 158 example results 167 molecular weight 169 monomer conversion 168 MWn 167 parameter regression 160 Styrene-butadiene chain length distribution 182 copolymer composition 190 degree of polymerization 190 example flowsheet 173, 185 example input summary 177, 187 example kinetics 175, 186 example process conditions 173, 186 example process studies 176 example rate constants 175 example results 180, 189 monomer mass 180

particle growth 180 particle nucleation 180 phase volumes 181 polymer composition 182 polymer mass 180 polymer properties 181 rate of consumption 189 Styrene-butadiene rubber See Styrene-butadiene Subroutines fortran 82 user 89 support, technical 3 Suspension polymerization 147– 56, 259–77 T technical support 3 Templates for simulations 6 Tertiary dodecyl mercaptane 172 Thermal conductivity predicting 28 results for 2,6 dimethyl phenol 35 Thermal initiation of polystyrene 121–32 Time limits 9 Titanium tetrachloride 261 Titles for simulations 8 Toluene 133 Triethyl-aluminium 261 U UNIPOL flowsheet 260 Unit operation blocks specification 16 Unit-sets defining 8 User models Aspen Polymers Plus-Predici interface 110–19 available models 92 installing fractionation 95 installing library 92 polymer fractionation algorithm 94–109 User2 models 92–119 V Van Krevelen group contribution 28

Vapor-liquid equilibrium 39 Vinyl acetate 51 Viscosity intrinsic 82 zero-shear 82 VK column 230 W web site, technical support 3 Z Zero-shear viscosity 82 Ziegler-Natta catalysts 192 Ziegler-Natta polymerization of ethylene 192–210 of polypropylene 259–77

288

Index

Aspen Polymer

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