Energy and Process Optimization for the Process Industries

Exploring methods and techniques to optimize processing energy efficiency in process plants, Energy and Process Optimization for the Process Industries provides a holistic approach that considers optimizing process conditions, changing process flowschemes, modifying equipment internals, and upgrading process technology that has already been used in a process plant with success. Field tested by numerous operating plants, the book describes technical solutions to reduce energy consumption leading to significant returns on capital and includes an 8-point Guidelines for Success. The book provides managers, chemical and mechanical engineers, and plant operators with methods and tools for continuous energy and process improvements.

Table of Contents:
PREFACE xv PART 1 BASIC CONCEPTS AND THEORY 1 1 Overview of this Book 3 1.1 Introduction, 3 1.2 Who is this Book Written for?, 4 1.3 Five Ways to Improve Energy Efficiency, 5 1.4 Four Key Elements for Continuous Improvement, 7 1.5 Promoting Improvement Ideas in the Organization, 8 2 Theory of Energy Intensity 9 2.1 Introduction, 9 2.2 Definition of Process Energy Intensity, 10 2.3 The Concept of Fuel Equivalent (FE), 11 2.4 Energy Intensity for a Total Site, 13 2.5 Concluding Remarks, 15 3 Benchmarking Energy Intensity 16 3.1 Introduction, 16 3.2 Data Extraction from Historian, 17 3.3 Convert All Energy Usage to Fuel Equivalent, 17 3.4 Energy Balance, 21 3.5 Fuel Equivalent for Steam and Power, 23 3.6 Energy Performance Index (EPI) Method, 29 3.7 Concluding Remarks, 32 4 Key Indicators and Targets 35 4.1 Introduction, 35 4.2 Key Indicators Represent Operation Opportunities, 36 4.3 Define Key Indicators, 39 4.4 Set up Targets for Key Indicators, 45 4.5 Economic Evaluation for Key Indicators, 49 4.6 Application 1: Implementing Key Indicators into an "Energy Dashboard," 53 4.7 Application 2: Implementing Key Indicators to Controllers, 56 4.8 It is Worth the Effort, 57 PART 2 ENERGY SYSTEM ASSESSMENT METHODS 59 5 Fired Heater Assessment 61 5.1 Introduction, 61 5.2 Fired Heater Design for High Reliability, 62 5.3 Fired Heater Operation for High Reliability, 68 5.4 Efficient Fired Heater Operation, 73 5.5 Fired Heater Revamp, 80 6 Heat Exchanger Performance Assessment 82 6.1 Introduction, 82 6.2 Basic Concepts and Calculations, 83 6.3 Understand Performance Criterion—U Values, 89 6.4 Understanding Pressure Drop, 94 6.5 Heat Exchanger Rating Assessment, 96 6.6 Improving Heat Exchanger Performance, 106 7 Heat Exchanger Fouling Assessment 112 7.1 Introduction, 112 7.2 Fouling Mechanisms, 113 7.3 Fouling Mitigation, 114 7.4 Fouling Mitigation for Crude Preheat Train, 117 7.5 Fouling Resistance Calculations, 119 7.6 A Cost-Based Model for Clean Cycle Optimization, 121 7.7 Revised Model for Clean Cycle Optimization, 125 7.8 A Practical Method for Clean Cycle Optimization, 128 7.9 Putting All Together—A Practical Example of Fouling Mitigation, 130 8 Energy Loss Assessment 138 8.1 Introduction, 138 8.2 Energy Loss Audit, 139 8.3 Energy Loss Audit Results, 147 8.4 Energy Loss Evaluation, 149 8.5 Brainstorming, 150 8.6 Energy Audit Report, 152 9 Process Heat Recovery Targeting Assessment 154 9.1 Introduction, 154 9.2 Data Extraction, 155 9.3 Composite Curves, 156 9.4 Basic Concepts, 159 9.5 Energy Targeting, 160 9.6 Pinch Golden Rules, 160 9.7 Cost Targeting: Determine Optimal DTmin, 162 9.8 Case Study, 165 9.9 Avoid Suboptimal Solutions, 169 9.10 Integrated Cost Targeting and Process Design, 171 9.11 Challenges for Applying the Systematic Design Approach, 172 10 Process Heat Recovery Modification Assessment 175 10.1 Introduction, 175 10.2 Network Pinch—The Bottleneck of Existing Heat Recovery System, 176 10.3 Identification of Modifications, 179 10.4 Automated Network Pinch Retrofit Approach, 181 10.5 Case Studies for Applying the Network Pinch Retrofit Approach, 183 11 Process Integration Opportunity Assessment 195 11.1 Introduction, 195 11.2 Definition of Process Integration, 196 11.3 Plus and Minus (+/-) Principle, 198 11.4 Grand Composite Curves, 199 11.5 Appropriate Placement Principle for Process Changes, 200 11.6 Examples of Process Changes, 205 PART 3 PROCESS SYSTEM ASSESSMENT AND OPTIMIZATION 225 12 Distillation Operating Window 227 12.1 Introduction, 227 12.2 What is Distillation?, 228 12.3 Distillation Efficiency, 229 12.4 Definition of Feasible Operating Window, 232 12.5 Understanding Operating Window, 232 12.6 Typical Capacity Limits, 253 12.7 Effects of Design Parameters, 255 12.8 Design Checklist, 257 12.9 Example Calculations for Developing Operating Window, 257 12.10 Concluding Remarks, 276 13 Distillation System Assessment 281 13.1 Introduction, 281 13.2 Define a Base Case, 281 13.3 Calculations for Missing and Incomplete Data, 284 13.4 Building Process Simulation, 287 13.5 Heat and Material Balance Assessment, 288 13.6 Tower Efficiency Assessment, 292 13.7 Operating Profile Assessment, 295 13.8 Tower Rating Assessment, 298 13.9 Column Heat Integration Assessment, 300 13.10 Guidelines for Reuse of an Existing Tower, 302 14 Distillation System Optimization 305 14.1 Introduction, 305 14.2 Tower Optimization Basics, 306 14.3 Energy Optimization for Distillation System, 312 14.4 Overall Process Optimization, 318 14.5 Concluding Remarks, 326 PART 4 UTILITY SYSTEM ASSESSMENT AND OPTIMIZATION 327 15 Modeling of Steam and Power System 329 15.1 Introduction, 329 15.2 Boiler, 330 15.3 Deaerator, 333 15.4 Steam Turbine, 334 15.5 Gas Turbine, 338 15.6 Letdown Valve, 339 15.7 Steam Desuperheater, 341 15.8 Steam Flash Drum, 342 15.9 Steam Trap, 342 15.10 Steam Distribution Losses, 344 16 Establishing Steam Balances 345 16.1 Introduction, 345 16.2 Guidelines for Generating Steam Balance, 346 16.3 AWorking Example for Generating Steam Balance, 347 16.4 A Practical Example for Generating Steam Balance, 357 16.5 Verify Steam Balance, 362 16.6 Concluding Remarks, 364 17 Determining True Steam Prices 366 17.1 Introduction, 366 17.2 The Cost of Steam Generation from Boiler, 367 17.3 Enthalpy-Based Steam Pricing, 371 17.4 Work-Based Steam Pricing, 372 17.5 Fuel Equivalent-Based Steam Pricing, 373 17.6 Cost-Based Steam Pricing, 376 17.7 Comparison of Different Steam Pricing Methods, 377 17.8 Marginal Steam Pricing, 379 17.9 Effects of Condensate Recovery on Steam Cost, 384 17.10 Concluding Remarks, 384 18 Benchmarking Steam System Performance 386 18.1 Introduction, 386 18.2 Benchmark Steam Cost: Minimize Generation Cost, 387 18.3 Benchmark Steam and Condensate Losses, 389 18.4 Benchmark Process Steam Usage and Energy Cost Allocation, 394 18.5 Benchmarking Steam System Operation, 396 18.6 Benchmarking Steam System Efficiency, 397 19 Steam and Power Optimization 403 19.1 Introduction, 403 19.2 Optimizing Steam Header Pressure, 404 19.3 Optimizing Steam Equipment Loadings, 405 19.4 Optimizing On-Site Power Generation Versus Power Import, 407 19.5 Minimizing Steam Letdowns and Venting, 412 19.6 Optimizing Steam System Configuration, 413 19.7 Developing Steam System Optimization Model, 417 PART 5 RETROFIT PROJECT EVALUATION AND IMPLEMENTATION 423 20 Determine the True Benefit from the OSBL Context 425 20.1 Introduction, 425 20.2 Energy Improvement Options Under Evaluation, 426 20.3 A Method for Evaluating Energy Improvement Options, 429 20.4 Feasibility Assessment and Make Decisions for Implementation, 442 21 Determine the True Benefit from Process Variations 447 21.1 Introduction, 447 21.2 Collect Online Data for the Whole Operation Cycle, 448 21.3 Normal Distribution and Monte Carlo Simulation, 449 21.4 Basic Statistics Summary for Normal Distribution, 456 22 Revamp Feasibility Assessment 459 22.1 Introduction, 459 22.2 Scope and Stages of Feasibility Assessment, 460 22.3 Feasibility Assessment Methodology, 462 22.4 Get the Project Basis and Data Right in the Very Beginning, 465 22.5 Get Project Economics Right, 466 22.6 Do Not Forget OSBL Costs, 470 22.7 Squeeze Capacity Out of Design Margin, 471 22.8 Identify and Relax Plant Constraints, 472 22.9 Interactions Between Process Conditions, Yields, and Equipment, 473 22.10 Do Not Get Misled by False Balances, 474 22.11 Prepare for Fuel Gas Long, 475 22.12 Two Retrofit Cases for Shifting Bottlenecks, 477 22.13 Concluding Remarks, 480 23 Create an Optimization Culture with Measurable Results 481 23.1 Introduction, 481 23.2 Site-Wide Energy Optimization Strategy, 482 23.3 Case Study of the Site-Wide Energy Optimization Strategy, 487 23.4 Establishing Energy Management System, 492 23.5 Energy Operation Management, 496 23.6 Energy Project Management, 499 23.7 An Overall Work Process from Idea Discovery to Implementation, 500 References, 502 INDEX 503

About the Author :
FRANK (Xin X.) ZHU is a Senior Fellow at UOP LLC, where he has led innovation efforts to optimize industrial process design and operation to achieve higher energy efficiency and lower capital cost. Before joining UOP, Dr. Zhu served as a research professor at the Centre for Process Integration at the University of Manchester in the UK. He is also a former editor-in-chief of CACS Communications, the magazine of the Chinese-American Chemical Society. He is the recipient of the 2014 AIChE Energy and Sustainability Award.