Efficient Petrochemical Processes

FRANK (XIN X.) ZHU, PHD, is Senior Fellow at Honeywell UOP, Des Plaines, Illionis. He is a leading expert in industrial process design, modeling, and energy efficiency. He holds 60 US patents; is the co-founder for ECI International Conference: CO2 Summit and the recipient of AIChE Energy Sustainability Award. JAMES A. JOHNSON is the Director of Petrochemical Development in the R&D Department of Honeywell UOP. He has authored several publications and holds 36 US patents. DAVID W. ABLIN was a Fellow at the Aromatics Technology Center of Honeywell UOP before retiring in 2016. He holds 14 U.S. patents and earned several UOP Engineering awards. GREGORY A. ERNST is a Technology Specialist at Honeywell UOP, focusing on aromatics technologies with experience in commissioning, field services, and on-site troubleshooting of operating plants.

• Preface xixAcknowledgments xxiPart I Market, Design and Technology Overview 11 Overview of This Book 31.1 Why Petrochemical Products are Important for the Economy 31.2 Overall Petrochemical Configurations 81.3 Context of Process Designs and Operation for Petrochemical Production 111.4 Who is This Book Written For? 112 Market and Technology Overview 132.1 Overview of Aromatic Petrochemicals 132.2 Introduction and Market Information 132.3 Technologies in Aromatics Synthesis 212.4 Alternative Feeds for Aromatics 272.5 Technologies in Aromatic Transformation 282.6 Technologies in Aromatic Separations 352.7 Separations by Molecular Weight 392.8 Separations by Isomer Type: para‐Xylene 392.9 Separations by Isomer Type: meta‐Xylene 442.10 Separations by Isomer Type: ortho‐Xylene and Ethylbenzene 452.11 Other Related Aromatics Technologies 462.12 Integrated Refining and Petrochemicals 57References 613 Aromatics Process Description 633.1 Overall Aromatics Flow Scheme 633.2 Adsorptive Separations for para‐Xylene 643.3 Technologies for Treating Feeds for Aromatics Production 683.4 para‐Xylene Purification and Recovery by Crystallization 683.5 Transalkylation Processes 713.6 Xylene Isomerization 723.7 Adsorptive Separation of Pure meta‐Xylene 763.8 para‐Selective Catalytic Technologies for para‐Xylene 78References 81Part II Process Design 834 Aromatics Process Unit Design 854.1 Introduction 854.2 Aromatics Fractionation 854.3 Aromatics Extraction 884.4 Transalkylation 964.5 Xylene Isomerization 1014.6 para‐Xylene Separation 1054.7 Process Design Considerations: Design Margin Philosophy 1064.8 Process Design Considerations: Operational Flexibility 1084.9 Process Design Considerations: Fractionation Optimization 1094.10 Safety Considerations 1104.10.1 Reducing Exposure to Hazardous Materials 1104.10.2 Process Hazard Analysis (PHA) 1104.10.3 Hazard and Operability (HAZOP) Study 110Further Reading 1115 Aromatics Process Revamp Design 1135.1 Introduction 1135.2 Stages of Revamp Assessment and Types of Revamp Studies 1135.3 Revamp Project Approach 1155.4 Revamp Study Methodology and Strategies 1165.5 Setting the Design Basis for Revamp Projects 1185.6 Process Design for Revamp Projects 1215.7 Revamp Impact on Utilities 1235.8 Equipment Evaluation for Revamps 1245.9 Economic Evaluation 1475.10 Example Revamp Cases 152Further Reading 154Part III Process Equipment Assessment 1556 Distillation Column Assessment 1576.1 Introduction 1576.2 Define a Base Case 1576.3 Calculations for Missing and Incomplete Data 1596.4 Building Process Simulation 1616.5 Heat and Material Balance Assessment 1626.6 Tower Efficiency Assessment 1646.7 Operating Profile Assessment 1666.8 Tower Rating Assessment 1686.9 Guidelines for Existing Columns 169Nomenclature 170Greek Letters 170References 1707 Heat Exchanger Assessment 1717.1 Introduction 1717.2 Basic Calculations 1717.3 Understand Performance Criterion: U‐Values 1737.4 Understand Fouling 1767.5 Understand Pressure Drop 1787.6 Effects of Velocity on Heat Transfer, Pressure Drop, and Fouling 1787.7 Improving Heat Exchanger Performance 1857.A TEMA Types of Heat Exchangers 186References 1888 Fired Heater Assessment 1898.1 Introduction 1898.2 Fired Heater Design for High Reliability 1898.3 Fired Heater Operation for High Reliability 1948.4 Efficient Fired Heater Operation 1978.5 Fired Heater Revamp 201References 2029 Compressor Assessment 2039.1 Introduction 2039.2 Types of Compressors 2039.3 Impeller Configurations 2059.4 Type of Blades 2079.5 How a Compressor Works 2079.6 Fundamentals of Centrifugal Compressors 2089.7 Performance Curves 2099.8 Partial Load Control 2109.9 Inlet Throttle Valve 2129.10 Process Context for a Centrifugal Compressor 2129.11 Compressor Selection 213References 21310 Pump Assessment 21510.1 Introduction 21510.2 Understanding Pump Head 21510.3 Define Pump Head: Bernoulli Equation 21610.4 Calculate Pump Head 21810.5 Total Head Calculation Examples 21910.6 Pump System Characteristics: System Curve 22110.7 Pump Characteristics: Pump Curve 22210.8 Best Efficiency Point (BEP) 22410.9 Pump Curves for Different Pump Arrangement 22510.10 NPSH 22610.11 Spillback 22910.12 Reliability Operating Envelope (ROE) 23010.13 Pump Control 23010.14 Pump Selection and Sizing 231Nomenclature 233Greek Letters 233References 233Part IV Energy and Process Integration 23511 Process Integration for Higher Efficiency and Low Cost 23711.1 Introduction 23711.2 Definition of Process Integration 23711.3 Composite Curves and Heat Integration 23811.4 Grand Composite Curves (GCC) 24411.5 Appropriate Placement Principle for Process Changes 24411.6 Systematic Approach for Process Integration 24911.7 Applications of the Process Integration Methodology 251References 26112 Energy Benchmarking 26312.1 Introduction 26312.2 Definition of Energy Intensity for a Process 26312.3 The Concept of Fuel Equivalent (FE) for Steam and Power 26412.4 Calculate Energy Intensity for a Process 26512.5 Fuel Equivalent for Steam and Power 26712.6 Energy Performance Index (EPI) Method for Energy Benchmarking 27112.7 Concluding Remarks 272References 27313 Key Indicators and Targets 27513.1 Introduction 27513.2 Key Indicators Represent Operation Opportunities 27513.3 Defining Key Indicators 27713.4 Set Up Targets for Key Indicators 28013.5 Economic Evaluation for Key Indicators 28313.6 Application 1: Implementing Key Indicators into an “Energy Dashboard” 28513.7 Application 2: Implementing Key Indicators to Controllers 28713.8 It is Worth the Effort 287References 28814 Distillation System Optimization 28914.1 Introduction 28914.2 Tower Optimization Basics 28914.3 Energy Optimization for Distillation System 29314.4 Overall Process Optimization 29614.5 Concluding Remarks 302References 30215 Fractionation and Separation Theory and Practices 30315.1 Introduction 30315.2 Separation Technology Overview 30315.3 Distillation Basics 30515.4 Advanced Distillation Topics 31115.5 Adsorption 31615.6 Simulated Moving Bed (SMB) 31715.7 Crystallization 32015.8 Liquid–Liquid Extraction 32015.9 Extractive Distillation 32115.10 Membranes 32215.11 Selecting a Separation Method 323References 32416 Reaction Engineering Overview 32516.1 Introduction 32516.2 Reaction Basics 32516.3 Reaction Kinetic Modeling Basics 32616.4 Rate Equation Based on Surface Kinetics 32816.5 Limitations in Catalytic Reaction 33016.6 Reactor Types 33316.7 Reactor Design 33516.8 Hybrid Reaction and Separation 34016.9 Catalyst Deactivation Root Causes and Modeling 341References 343Part V Operational Guidelines and Troubleshooting 34517 Common Operating Issues 34717.1 Introduction 34717.2 Start‐up Considerations 34817.3 Methyl Group and Phenyl Ring Losses 34917.4 Limiting Aromatics Losses 35017.5 Fouling 35617.6 Aromatics Extraction Unit Solvent Degradation 36017.7 Selective Adsorption of para‐Xylene by Simulated Moving Bed 36317.8 Common Issues with Sampling and Laboratory Analysis 37117.9 Measures of Operating Efficiency in Aromatics Complex Process Units 37417.10 The Future of Plant Troubleshooting and Optimization 377References 37718 Troubleshooting Case Studies 37918.1 Introduction 37918.2 Transalkylation Unit: Low Catalyst Activity During Normal Operation 37918.3 Xylene Isomerization Unit: Low Catalyst Activity Following Start‐up 38118.4 para‐Xylene Selective Adsorption Unit: Low Recovery After Turnaround 38418.5 Aromatics Extraction Unit: Low Extract Purity/Recovery 38518.6 Aromatics Complex: Low para‐Xylene Production 38618.7 Closing Remarks 388Reference 389Index 391