Process Dynamics and Control

This third edition provides chemical engineers with process control techniques that are used in practice while offering detailed mathematical analysis. Numerous examples and simulations are used to illustrate key theoretical concepts. New exercises are integrated throughout several chapters to reinforce concepts. Up-to-date information is also included on real-time optimization and model predictive control to highlight the significant impact these techniques have on industrial practice. And chemical engineers will find two new chapters on biosystems control to gain the latest perspective in the field.

Table of Contents:
PART ONE INTRODUCTION TO PROCESS CONTROL 1. Introduction to Process Control 1 1.1 Representative Process Control Problems 1 1.2 Illustrative Example-A Blending Process 3 1.3 Classification of Process Control Strategies 5 1.4 A More Complicated Example-A Distillation Column 7 1.5 The Hierarchy of Process Control Activities 8 1.6 An Overview of Control System Design 10 2. Theoretical Models of Chemical Processes 15 2.1 The Rationale for Dynamic Process Models 15 2.2 General Modeling Principles 17 2.3 Degrees of Freedom Analysis 21 2.4 Dynamic Models of Representative Processes 22 2.5 Process Dynamics and Mathematical Models 35 PART TWO DYNAMIC BEHAVIOR OF PROCESSES 3. Transfer Function Models 43 3.1 An Illustrative Example: A Continuous Blending System 43 3.2 Transfer Functions of Complicated Models 45 3.3 Properties of Transfer Functions 46 3.4 Linearization of Nonlinear Models 49 4. Dynamic Behavior of First-Order and Second-Order Processes 58 4.1 Standard Process Inputs 58 4.2 Response of First-Order Processes 61 4.3 Response of Integrating Processes 64 4.4 Response of Second-Order Processes 66 5. Dynamic Response Characteristics of More Complicated Processes 78 5.1 Poles and Zeros and Their Effect on Process Response 78 5.2 Processes with Time Delays 82 5.3 Approximation of Higher-Order Transfer Functions 86 5.4 Interacting and Noninteracting Processes 88 5.5 State-Space and Transfer Function Matrix Models 90 5.6 Multiple-Input, Multiple-Output (MIMO) Processes 93 6. Development of Empirical Models from Process Data 102 6.1 Model Development Using Linear or Nonlinear Regression 103 6.2 Fitting First- and Second-Order Models Using Step Tests 107 6.3 Neural Network Models 112 6.4 Development of Discrete-Time Dynamic Models 113 6.5 Identifying Discrete-Time Models from Experimental Data 115 PART THREE FEEDBACK AND FEEDFORWARD CONTROL 7. Feedback Controllers 124 7.1 Introduction 124 7.2 Basic Control Modes 126 7.3 Features of PID Controllers 131 7.4 On-Off Controllers 134 7.5 Typical Responses of Feedback Control Systems 134 7.6 Digital Versions of PID Controllers 135 8. Control System Instrumentation 141 8.1 Sensors, Transmitters, and Transducers 142 8.2 Final Control Elements 147 8.3 Signal Transmission and Digital Communication 153 8.4 Accuracy in Instrumentation 154 9. Process Safety and Process Control 160 9.1 Layers of Protection 161 9.2 Alarm Management 165 9.3 Abnormal Event Detection 169 9.4 Risk Assessment 171 10. Dynamic Behavior and Stability of Closed-Loop Control Systems 176 10.1 Block Diagram Representation 176 10.2 Closed-Loop Transfer Functions 179 10.3 Closed-Loop Responses of Simple Control Systems 182 10.4 Stability of Closed-Loop Control Systems 188 10.5 Root Locus Diagrams 194 11. PID Controller Design, Tuning, and Troubleshooting 204 11.1 Performance Criteria for Closed-Loop Systems 204 11.2 Model-Based Design Methods 206 11.3 Controller Tuning Relations 211 11.4 Controllers with Two Degrees of Freedom 216 11.5 On-Line Controller Tuning 217 11.6 Guidelines for Common Control Loops 223 11.7 Troubleshooting Control Loops 225 12. Control Strategies at the Process Unit Level 232 12.1 Degrees of Freedom Analysis for Process Control 232 12.2 Selection of Controlled, Manipulated, and Measured Variables 234 12.3 Applications 238 13. Frequency Response Analysis and Control System Design 248 13.1 Sinusoidal Forcing of a First-Order Process 248 13.2 Sinusoidal Forcing of an nth-Order Process 249 13.3 Bode Diagrams 251 13.4 Frequency Response Characteristics of Feedback Controllers 255 13.5 Nyquist Diagrams 260 13.6 Bode Stability Criterion 260 13.7 Gain and Phase Margins 264 14. Feedforward and Ratio Control 271 14.1 Introduction to Feedforward Control 271 14.2 Ratio Control 273 14.3 Feedforward Controller Design Based on Steady-State Models 275 14.4 Feedforward Controller Design Based on Dynamic Models 277 14.5 The Relationship Between the Steady-State and Dynamic Design Methods 281 14.6 Configurations for Feedforward-Feedback Control 282 14.7 Tuning Feedforward Controllers 282 PART FOUR ADVANCED PROCESS CONTROL 15. Enhanced Single-Loop Control Strategies 288 15.1 Cascade Control 288 15.2 Time-Delay Compensation 293 15.3 Inferential Control 296 15.4 Selective Control/Override Systems 297 15.5 Nonlinear Control Systems 300 15.6 Adaptive Control Systems 307 16. Multiloop and Multivariable Control 317 16.1 Process Interactions and Control Loop Interactions 317 16.2 Pairing of Controlled and Manipulated Variables 323 16.3 Singular Value Analysis 330 16.4 Tuning of Multiloop PID Control Systems 334 16.5 Decoupling and Multivariable Control Strategies 334 16.6 Strategies for Reducing Control Loop Interactions 336 17. Digital Sampling, Filtering, and Control 344 17.1 Sampling and Signal Reconstruction 344 17.2 Signal Processing and Data Filtering 347 17.3 z-Transform Analysis for Digital Control 352 17.4 Tuning of Digital PID Controllers 358 17.5 Direct Synthesis for Design of Digital Controllers 360 17.6 Minimum Variance Control 364 18. Batch Process Control 371 18.1 Batch Control Systems 373 18.2 Sequential and Logic Control 374 18.3 Control During the Batch 380 18.4 Run-to-Run Control 386 18.5 Batch Production Management 387 Chapters 19 through 23 are online at www.wiley.com/go/global/seborg 19. Real-Time Optimization 395 19.1 Basic Requirements in Real-Time Optimization 396 19.2 The Formulation and Solution of RTO Problems 399 19.3 Unconstrained and Constrained Optimization 401 19.4 Linear Programming 404 19.5 Quadratic and Nonlinear Programming 408 20. Model Predictive Control 414 20.1 Overview of Model Predictive Control 414 20.2 Predictions for SISO Models 416 20.3 Predictions for MIMO Models 421 20.4 Model Predictive Control Calculations 423 20.5 Set-Point Calculations 427 20.6 Selection of Design and Tuning Parameters 429 20.7 Implementation of MPC 434 21. Process Monitoring 439 21.1 Traditional Monitoring Techniques 440 21.2 Quality Control Charts 441 21.3 Extensions of Statistical Process Control 447 21.4 Multivariate Statistical Techniques 449 21.5 Control Performance Monitoring 451 PART FIVE APPLICATIONS TO BIOLOGICAL SYSTEMS 22. Biosystems Control Design 456 22.1 Process Modeling and Control in Pharmaceutical Operations 456 22.2 Process Modeling and Control for Drug Delivery 462 23. Dynamics and Control of Biological Systems 470 24.1 Systems Biology 470 24.2 Gene Regulatory Control 472 24.3 Signal Transduction Networks 476 Appendix A: Laplace Transforms A-1 A.1 The Laplace Transform of Representative Functions A-1 A.2 Solution of Differential Equations by Laplace Transform Techniques A-5 A.3 Partial Fraction Expansion A-7 A.4 Other Laplace Transform Properties A-10 A.5 A Transient Response Example A-13 Appendix B: Digital Process Control Systems: Hardware and Software A-21 B.1 Distributed Digital Control Systems A-22 B.2 Analog and Digital Signals and Data Transfer A-22 B.3 Microprocessors and Digital Hardware in Process Control A-24 B.4 Software Organization A-27 Appendix C: Review of Thermodynamic Concepts for Conservation Equations A-34 C.1 Single-Component Systems A-34 C.2 Multicomponent Systems A-35 Appendix D: Control Simulation Software A-36 D.1 MATLAB Operations and Equation Solving A-36 D.2 Computer Simulation with Simulink A-38 D.3 Computer Simulation with LabVIEW A-40 Appendix E: Process Control Modules A-43 E.1. Introduction A-43 E.2. Module Organization A-43 E.3. Hardware and Software Requirements A-44 E.4. Installation A-44 E.5. Running the Software A-44 Appendices F through K are online at www.wiley.com/go/global/seborg Appendix F: Introduction to Plantwide Control A-45 F.1 Plantwide Control Issues A-45 F.2 Hypothetical Plant for Plantwide Control Studies A-47 F.3 Internal Feedback of Material and Energy A-51 F.4 Interaction of Plant Design and Control System Design A-59 Appendix G: Plantwide Control System Design A-63 G.1 Procedures for the Design of Plantwide Control Systems A-63 G.2 A Systematic Procedure for Plantwide Control System Design A-64 G.3 Case Study: The Reactor/Flash Unit Plant A-67 G.4 Effect of Control Structure on Closed-Loop Performance A-78 Appendix H: Dynamic Models and Parameters Used for Plantwide Control Chapters A-82 H.1 Energy Balance and Parameters for the Reactor/Distillation Column Model A-82 H.2 Core Reactor/Flash Unit Model and Parameters A-82 Appendix I: Instrumentation Symbols A-88 Appendix J: Review of Basic Concepts from Probability and Statistics A-90 J.1 Probability Concepts A-90 J.2 Means and Variances A-91 J.3 Standard Normal Distribution A-91 J.4 Error Analysis A-92 Appendix K: Contour Mapping and the Principle of the Argument A-93 K.1 Development of the Nyquist Stability Criterion A-93 Index I-1