Optimization of Chemical Processes
Cheng-Liang Chen
PSE
LABORATORY
Department of Chemical Engineering National TAIWAN University
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Optimization of Chemical Processes (cont.)
The chemical industry has undergone significant changes during the past 25 years due to the
increased cost of energy, increasingly stringent environmental regulations, and global competition in product pricing and quality
One of the most important engineering tools for addressing these issues is optimization
Modifications in plant design and operating procedures have been implemented to reduce costs and meet constraints, with an emphasis on improving efficiency and increasing profitability
Optimal operating conditions can be implemented via increased automation at the process, plant, and company levels
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Optimization of Chemical Processes (cont.)
As the power of computers has increased, the size and complexity of problems that can be solved by optimization techniques have correspondingly expanded.
To apply optimization effectively in the chemical industries, both the theory and practice of optimization must be understood.
We will introduce the necessary tools for problem solving. We will focus on those techniques and discuss software that offers the most potential for success and gives reliable results.
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References
Arora, J.S., Introduction to Optimum Design, McGraw Hill, New York (1989)
Floudas, C., Nonlinear and Mixed-Integer Optimization, Oxford University Press (1995)
Floudas, C., Deterministic Global Optimization, Kluwer Academic Publishers (1999)
Edgar, T.F., D.M. Himmelblau, and L.S. Lasdon, Optimization of Chemical Processes, 2nd Edition, McGraw-Hill, Boston (2000)
Morari, M. and I.E. Grossmann, Process Design Case Studies (6): Chemical Engineering Models with GAMS , CACHE (1991)
Biegler, L.T., E.I. Grossmann, and A.W. Westerberg, Systematic Methods of Chemical Process Design, Prentice Hall, New Jersey (1997)
Smith, R., Chemical Process Design and Integration, 2nd Ed., Wiley, England (2005)
Rao, S.S., Engineering Optimization, John Wiley, New York (1984).
Reklaitis, G.V., A. Ravindran, and K,M, Ragsdell, Engineering Optimization, John Wiley, New York (1983)
Vanderplaats, G.N., Numerical Optimization Techniques for Engineering Design with Applications, McGraw-Hill, Boston (1984)
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Contents of Arora (cont.)
Introduction to Optimum Design Conventional versus Optimum Design Processes Role of Computers in Optimum Design Basic Terminology and Notations
Optimum Design Problem Formulation Design Variables, Cost Function, and Design Constraints Examples of Optimum Design Problem Formulation
Optimum Design Concepts Fundamental Concepts Unconstrained Optimum Design Problems Constrained Optimum Design Problems Global Optimality Post-optimality Analysis
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Contents of Arora (cont.)
Linear Programming Definition of Standard LP Problems Basic Concepts Related to LP Problems The Simplex Method Initial Basic Feasible Solution – Artificial Variables Post-optimality Analysis
Numerical Methods for Unconstrained Optimization General Concepts Related to Numerical Algorithms One-dimensional Minimization Steepest Descent Method Conjugate Gradient Method Newton’s Method Quasi-Newton Methods
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Contents of Arora (cont.)
Numerical Methods for Constrained Optimization Basic Concepts and Ideas Sequential Unconstrained Optimization Algorithm Linearization of Constrained Problem Sequential Linear Programming Algorithms Quadratic Programming Subproblem Constrained Steepest Descent Method Constrained Quasi-Newton Methods
Interactive Design Optimization
Practical Design Optimization
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Contents of Floudas (cont.)
Introduction Mathematical and Optimization Models Structure of Nonlinear and Mixed-Integer Optimization Models Illustrative Applications
Part 1: Fundamentals of Convex Analysis and Nonlinear Optimization
Convex Analysis Convex Sets Convex and Concave Functions
Fundamentals of Nonlinear Optimization Unconstrained Nonlinear Optimization Constrained Nonlinear Optimization
Duality Theory Primal Problem Dual Problem
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Contents of Floudas (cont.) Part 2: Fundamentals of Mixed-Integer Optimization
Mixed-Integer Linear Optimization Motivation and Formulation Branch and Bound Method
Mixed-Integer Nonlinear Optimization Motivation and Formulation Generalized Benders Decomposition (GBD) Outer Approximations (OA) Outer Approximations with Equality Relaxation (OA/ER) Outer Approximations with Equality Relaxation and Augmented Penalty (OA/ER/AP) Generalized Outer Approximations (GOA) Generalized Cross Decomposition (GCD)
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Contents of Floudas (cont.) Part 3: Applications in Process Synthesis
Process Synthesis Difficulties/Challenges in Process Synthesis Optimization Approach in Process Synthesis
Heat Exchanger Network Synthesis
Distillation-based Separation Systems Synthesis
Synthesis of Reactor Networks and Reactor-SeparatorRecycle Systems
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Contents of Floudas’ Global Optimization
Introduction; Basic concepts of Global Optimization
The αBB Box Constrained Twice-diff. NLPs: Theory
The αBB
Constrained Twice-diff. NLPs: Theory
Computational Studies of The αBB Approach
Introduction to Nonlinear and Mixed-integer Optimization
The SMIN-αBB Approach: Theory and Computations
The GMIN-αBB Approach: Theory and Computations
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Contents of Edgar (cont.) I Problem Formulation
The Nature and Organization of Optimization Problems
Developing Models for Optimization
Formulation of the Objective Function II
Optimization Theory and Methods
Basic Concepts of Optimization
Optimization of Unconstrained Functions: One-Dimensional Search
Unconstrained Multi-variable Optimization
Linear Programming and Applications
Nonlinear Programming with Constraints
Mixed-Integer Programming
Global Optimization for Problems with Continuous and Discrete Variables
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Contents of Edgar (cont.) III
Applications of Optimization
Hear Transfer and Energy Conservation
Separation Processes
Fluid Flow Systems
Chemical Reactor Design and Operation
Optimization in Large-Scale Plant Design and Operations
Integrated Planning, Scheduling, and Control in the Process Industries
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Contents of Biegler (cont.)
Introduction to Process Design I Preliminary Analysis and Evaluation of Processes
Overview of Flowsheet Synthesis
Mass and Energy Balances
Equipment Sizing and Costing
Economic Evaluation
Dsign and Scheduling of Batch Processes II Analysis with Rigorous Process Models
Unit Equation Models
General Concepts of Simulation for Process Design
Process Flowsheet Optimization
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Contents of Biegler (cont.) III Basic Concepts in Process Synthesis
Heat and Power Integration
Ideal Distillation Systems
Heat Integrated Distillation Processes
Geometric Techniques for Synthesis of Reactor Networks
Separating Azeotropic Mixtures
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Contents of Biegler (cont.) IV Optimization Approaches to Process Synthesis
Basic Concepts for Algorithmic Methods
Synthesis of Heat Exchange Networks
Synthesis of Distillation Sequences
Simultaneous Optimization and Heat Integration
Optimization Techniques for Reactor Network Syntheses
Structural Optimization of Process Flowsheets
Process Flexibility
Optimal Design and Scheduling for Multiproduct Batch Plants
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Contents of Smith (cont.)
The Nature of Chemical Process Design and Integration
Process Economics
Optimization
Thermodynamic Properties and Phase Equilibrium
Choice of Reactor I
Choice of Reactor II – Reactor Conditions
Choice of Reactor III – Reactor configuration
Choice of Separator for Heterogeneous Mixtures
Choice of Separator for Homogeneous Fluid Mixtures I – Distillation
Choice of Separator for Homogeneous Fluid Mixtures II – Other Methods
Distillation Sequencing
Distillation Sequencing for Azeotropic Distillation
Reaction, Separation and Recycle Systems for Continuous Processes
Reaction, Separation and Recycle Systems for Batch Processes
– Reactor Performance
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Contents of Smith (cont.)
Heat Exchanger Networks I – Heat Transfer Equipment
Heat Exchanger Networks II – Energy Targets
Heat Exchanger Networks III – Capital and Total Cost Targets
Heat Exchanger Networks IV – Network Design
Heat Exchanger Networks V – Stream Data
Heat Integration of Reactors
Heat Integration of Distillation Columns
Heat Integration of Evaporators and Dryers
Steam Systems and Cogeneration
Cooling and Refrigeration
Environmental Design for Atmospheric Emissions
Water System Design
Inherent Safety
Clean Process Technology
Overall Strategy for Chemical Process Design and Integration
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Case Studies Using GAMS (cont.)
Refinery Scheduling
Production Planning in Multi-purpose Batch Plants
LP Model for Minimizing Utility Cost in A Heat Exchanger Network
Logical Inference for Reaction Path Synthesis
Design of A Chemical Complex
Multi-product Batch Plant Scheduling
Multi-period MILP Model for Planning of Chemical Complexes
Power Generation via Fuel Oil
Alkylation Process Optimization
Chemical Equilibrium
Multi-Component Phase Equilibrium
Global Optimum Search in Heat Exchanger Network Configurations
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Case Studies Using GAMS (cont.)
Optimal Selection of Processes
Optimal Design of Multi-product Batch Plants
Simultaneous Optimization Model for Heat Exchanger Network Synthesis
Heat Integrated Distillation Sequences
Non-sharp Distillation Synthesis
Optimum Feed Plate Location
Minimum Time to Cover A Fixed Distance
Catalyst Mixing for Packed Bed Reactor
Parameter Estimation for A Simple Batch Reactor System
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Course Outlines Arora
Floudas/Biegler
Int to Optimum Design
Edgar
MATLAB
GAMS
Problems
Problem Formulation
Math and Opt Models
Optimum Design Concepts
Convex
Models
Analysis;
Fundamentals of Nonlinear Opt; Duality Theory
Linear Programming
** MILP; Logical Constraints
*
*
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Num. Unconst. Opt.
*
**
*
Num. Const. Opt.
*
**
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MINLP; Process Synthesis
*
Global Optimization
Some Special Topics:
Smith
Synthesis of Heat/Mass Exchanger Networks (include Pinch Analysis)
Synthesis of Water Networks, Cooling Water Networks
Batch Scheduling; Supply Chain Management;
...
***
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Credits
5
Homeworks
(40%)
Mid-term Examination
(25%)
Final Examination
(25%)
Oral Presentation of Assigned Materials
(10%)
∼
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