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Efficient Petrochemical Technology for Growth: Design Integration and Operation Optimization





Efficient Petrochemical Technology for Growth: Design Integration and Operation Optimization



This book covers the application of methods and tools for energy optimization and process design. It focuses the application of these methods on petrochemical process units such as the aromatics process unit. The book provides practical methods and tools to industrial practitioners with the focus on improving industrial energy efficiency, reducing capital investment, and optimizing yields via better design, operation, and optimization.
Broken down into six parts the book covers a range of topics including: Aromatics Process Description; Process Design Considerations; Petrochemical Separation Design; Process Integration; Process system optimization; Types of revamps; Equipment assessment; Common operating issues; and Troubleshooting case analysis to name a few.



Part 1: Basics

1. Overview of This Book

1.1 Why Petrochemical Products are Important for the Economy?

1.1.1 Polyethylene

1.1.2 Polypropylene

1.1.3 Styrene and Polystyrene

1.1.4 Polyester

1.1.5 Polycarbonate and Phenolic Resins

1.1.6 Economic Significance of Polymers

1.1.7 Petrochemicals and Petroleum Utilization

1.2 Overall Petrochemical Complex Configurations

1.3 Context of Process Design and Operation for Petrochemical Production

1.4 Who is this Book Written for?

2 Market and Technology Overview

2.1 Overview of Aromatic Petrochemicals

2.2 Introduction and Market Information

2.2.1 Benzene

2.2.2 Benzene Production Technologies

2.2.3 Toluene

2.2.4 Toluene Production Technologies

2.2.5 Ethylbenzene/Styrene

2.2.6 Ethylbenzene/Styrene Production Technologies

2.2.7 Para-Xylene

2.2.8 Para-Xylene Production Technologies

2.2.9 Meta-Xylene

2.2.10 Meta-Xylene Production Technologies

2.2.11 Ortho-Xylene

2.2.12 Ortho-Xylene Production Technologies

2.2.13 Cumene/Phenol

2.2.14 Cumene/Phenol Production Technologies

2.3 Technologies in Aromatics Synthesis

2.4 Alternative Feeds for Aromatics

2.5 Technologies in Aromatic Transformation

2.5.1 Transalkylation

2.5.2 Selective Toluene Disproportionation

2.5.3 Thermal Hydro-Dealkylation

2.5.4 Xylene Isomerization

2.6 Technologies in Aromatics Separations

2.6.1 Liquid-Liquid Extraction and Extractive Distillation

2.6.2 Liquid-Liquid Extraction

2.6.3 Extractive Distillation (ED)

2.7 Separations by Molecular Weight

2.8 Separations by Isomer Type – Para-Xylene

2.8.1 Crystallization of Para-Xylene

2.8.2 Adsorptive Separation of Para-Xylene

2.9 Separations by Isomer Type – Meta-Xylene

2.10 Separations by Isomer Type – Ortho-Xylene and Ethylbenzene

2.11 Other Related Aromatics Technologies

2.11.1 Cyclohexane

2.11.2 Ethylbenzene/Styrene

2.11.3 Cumene/Phenol/Bisphenol A

2.11.4 Linear Alkyl Benzene Sulfonate for Detergents

2.11.5 Oxidation of Para- and Meta-Xylene

2.11.6 Melt Phase Polymerization of PTA to PET

2.11.7 Melt Phase Polymerization and Solid State Polymerization of PET Resin

2.11.8 Oxidation of Ortho-Xylene

2.12 Integrated Refining and Petrochemicals

3 Aromatics Process Description

3.1 Overall Aromatics Flowscheme

3.2 Adsorptive Separations for Para-Xylene

3.3 Technologies for Treating Feeds for Aromatics Production

3.4 Para-Xylene Purification and Recovery by Crystallization

3.5 Transalkylation Processes

3.6 Xylene Isomerization

3.7 Adsorptive Separation of Pure Meta-Xylene

3.8 Para-Selective Catalytic Technologies for Para-Xylene

3.8.1 Para-selective Toluene Disproportionaiton

3.8.2 Para-selective Toluene Methylation

Part 2: Process Design

4 Aromatic Process Unit Design (Dave; done)

4.1 Introduction

4.2 Aromatics Fractionation

4.2.1 Reformate Splitter

4.2.2 Xylene Fractionation

4.2.3 Heavy Aromatics Fractionation

4.3 Aromatic Extraction

4.3.1 Liquid-Liquid Extraction Operating Variables

4.3.2 Extractive Distillation Operating Variables

4.4 Transalkylation

4.4.1 Process Flow Description

4.5 Xylene Isomerization

4.6 Para-Xylene Separation

4.7 Process Design Considerations – Design Margin Philosophy

4.7.1 Equipment Design Margins

4.8 Process Design Considerations – Operational Flexibility

4.9 Process Design Considerations – Fractionation Optimization

4.10 Safety Considerations

4.10.1 Reducing Exposure to Hazardous Materials

4.10.2 Process Hazard Analysis (PHA)

4.10.3 Hazard and Operability Study (HAZOP)

4.11 References

5 Aromatics Process Revamp Design

5.1 Introduction

5.2 Stages of Revamp Assessment and Types of Revamp Studies

5.3 Revamp Project Approach

5.3.1 Specified Target Capacity

5.3.2 Target Production with Constraints

5.3.3 Maximize Throughput at Minimum Cost

5.3.4 Identify Successive bottlenecks

5.4 Revamp Study Methodology and Strategies

5.5 Setting the Design Basis for Revamp Projects

5.5.1 Agreement

5.5.2 Processing Objectives

5.5.3 Define the Approach of the Study

5.5.4 Feedstock and Make-up Gas

5.5.5 Product Specifications

5.5.6 Getting the Right Equipment Information

5.5.7 Operating Data or Test Run Data

5.5.8 Constraints

5.5.9 Utilities

5.5.10 Replacement Equipment Options

5.5.11 Guarantees

5.5.12 Economic Evaluation Criteria

5.6 Process Design for Revamp Projects

5.6.1 Adjusting Operating Conditions

5.6.2 Design margin

5.7 Revamp Impact on Utilities

5.8 Equipment Evaluation for Revamps

5.8.1 Fired Heaters Data Required Fired Heater Evaluation Heater Design Limitations Radiant Flux Limits Tube Wall Temperature (TWT) Limits Metallurgy Tube Thickness Coil Pressure Drop Burners

5.8.2 Vessels – Separators, Receivers, and Drums Data required Separator, Receiver, and Drum Evaluation Process and Other Modifications Test Run Data Possible Recommendations

5.8.3 Reactors Data Required Reactor Process Evaluation Process and Other Modifications Test Run Data Possible Recommendations

5.8.4 Fractionators Data Required Fractionator Evaluation Retraying and Other Modifications High Capacity Trays Test Run data Possible Recommendations

5.8.5 Heat Exchangers Data Required Overall Exchanger Evaluation Thermal Rating Methods Rating Procedures Pressure Drop Estimation Use of Operating Data Possible Recommendations Special Exchanger Services Overpressure Protection

5.8.6 Pumps Data Required Centrifugal Pump Evaluation Proportioning Pumps Use of Operating Data Possible Recommendations Tools Special Pump Services

5.8.7 Compressors Data Required Centrifugal Compressor Evaluation Reciprocating Compressor Evaluation Driver Power Materials of Construction Use of Operating data Potential Remedies

5.8.8 Hydraulics/Piping New Unit Line Sizing Criteria are Generally Not Applicable Pressure Drop Requires Replacement of Other Equipment Approaching Sonic Velocity Erosion Concerns Pressure Drop Affects Yield Pressure Drop Affects Fractionator Operation or Utilities

5.9 Economic Evaluation

5.9.1 Costs

5.9.2 Benefits

5.9.3 Data Requirements

5.9.4 Types of Economic Analyses

5.10 Example Revamp Cases

5.10.1 Aromatics Complex Revamp with Adsorbent Reload

5.10.2 Aromatics Complex Revamp with Xylene Isomerization Catalyst Change

5.10.3 Transalkylation Unit Revamp

5.11 References

Part 3: Process Equipment Assessment

6 Distillation Column Assessment

6.1 Introduction

6.2 Define a Base Case

6.3 Calculations for Missing and Incomplete Data

6.4 Building a Process Simulation

6.5 Heat and Material Balance Assessment

6.6 Tower Efficiency Assessment

6.7 Operating Profile Assessment

6.8 Tower Rating Assessment

6.9 Guidelines

6.10 Nomenclature

6.11 References

7 Heat Exchanger Assessment

7.1 Introduction

7.2 Basic Concepts and Calculations

7.3 Understand Performance Criterion – U Value

7.3.1 Required U Value (UR)

7.3.2 Clean U Value (UC)

7.3.3 Actual U Value (UA)

7.3.4 Overdesign (ODA)

7.3.5 Controlling Resistance

7.4 Understand Fouling

7.4.1 Root Causes of Fouling

7.4.2 Estimate Fouling Factor (Rf)

7.4.3 Determine Additional Pressure Drop Due to Fouling

7.5 Understand Pressure Drop

7.5.1 Tube Side Pressure Drop

7.5.2 Shell Side Pressure Drop

7.6 Effects of Velocity on Heat Transfer, Pressure Drop, and Fouling

7.6.1 Heat Exchanger Rating Assessment

7.6.2 Assess the Suitability of an Existing Exchanger for Changing Conditions

7.6.3 Determine Arrangement of Heat Exchangers in Series or Parallel

7.6.4 Assess Heat Exchanger Fouling

7.7 Improving Heat Exchanger Performance

7.7.1 How to Identify Deteriorating Performance

7.8 Nomenclature

7.9 References

8 Fired Heater Assessment

8.1 Introduction

8.2 Fired Heater Design for High Reliability

8.2.1 Flux Rate

8.2.2 Burner to Tube Clearance

8.2.3 Burner Selection

8.2.4 Fuel conditioning System

8.3 Fired Heater Operation for High Reliability

8.4 Efficient Fired Heater Operation

8.5 Fired Heater Revamp

8.6 Nomenclature

8.7 References

9 Compressor Assessment

9.1 Introduction

9.2 Types of Compressors

9.2.1 Multistage Beam Type Compressor

9.2.2 Multistage Integral Geared Compressor

9.3 Impeller Configurations

9.3.1 Between-Bearing Configuration

9.3.2 Integrally Geared Configuration

9.4 Types of Blades

9.5 How a Compressor Works

9.6 Fundamentals of Centrifugal Compressors

9.7 Performance Curves

9.8 Partial Load Control

9.9 Inlet Throttle Valve

9.10 Process Context for a Centrifugal Compressor

9.11 Compressor Selection

9.12 References

10 Pump Assessment

10.1 Introduction

10.2 Understanding Pump Head

10.3 Define Pump Head – Bernoulli Equation

10.4 Calculate Pump Head

10.5 Total Head Calculation Examples

10.6 Pump System Characteristics – System Curve

10.7 Pump Characteristics – Pump Curve

10.8 Best Efficiency Point (BEP)

10.9 Pump Curves for Different Pump Arrangements

10.10 Net Positive Suction Head (NPSH)

10.10.1 Calculation of NPSHA

10.10.2 NPSH Margin

10.10.3 Measuring NPSHA for Existing Pumps

10.10.4 Low NPSH Potential Causes and Mitigation

10.11 Spillback

10.12 Reliability Operating Envelope (ROE)

10.13 Pump Control

10.14 Pump Selection and Sizing

10.15 Nomenclature

10.16 References

Part 4: Energy & Process Optimization

11 Process Integration for Higher Efficiency and Low Cost

11.1 Introduction

11.2 Definition of Process Integration

11.3 Composite Curves and Heat Integration

11.3.1 Composite Curves

11.3.2 Basic Pinch Concepts

11.3.3 Energy Use Targeting

11.3.4 Pinch Design Rules

11.3.5 Cost Targeting: Determine Optimal Tmin

11.4 Grand Composite Curves (GCC)

11.5 Appropriate Placement Principle for Process Changes

11.5.1 General Principle for Appropriate Placement

11.5.2 Appropriate Placement for Utility

11.5.3 Appropriate Placement for Reaction Process

11.5.4 Appropriate Placement for Distillation Column The Column Grand Composite Curve (CGCC) Column Integration Against Background Process Design Procedure for Column Integration

11.6 Systematic Approach for Process Integration

11.7 Applications of the Process Integration Methodology

11.7.1 Column Split for Xylene Column with Thermal Coupling

11.7.2 Column Split for Extract Column with Thermal Coupling

11.7.3 Use of Dividing-Wall columns (DWC)

11.7.4 Use of Light Desorbent

11.7.5 Heat Pump for Para-Xylene Column

11.7.6 Indirect Column Heat Integration

11.7.7 Benefit of Column Integration

11.7.8 Process-Process Stream Heat Integration

11.7.9 Power Recovery Organic Rankine Cycle for Low temperature Heat Recovery Variable Frequency Driver on Adsorbent Chamber Circulation Pumps

11.7.10 Process Integration Summary

11.8 References

12 Energy Benchmarking 

12.1 Introduction

12.2 Definition of Energy Intensity for a Process

12.3 The Concept of Fuel Equivalent (FE) for Steam and Power

12.4 Calculate Energy Intensity for a Process

12.5 Fuel Equivalent for Steam and Power

12.5.1 FE Factors for Power (FEpower)

12.5.2 FE Factors for Steam, Condensate, and Water

12.6 Energy Performance Index (EPI) Method for Energy Benchmarking

12.6.1 Benchmarking: Based on the Best-in-Operation Energy Performance (OEP)

12.6.2 Benchmarking: Based on Industrial Peers’ Energy Performance (PEP)

12.6.3 Benchmarking: Based on the Best Technology Energy Performance (TEP)

12.7 Concluding Remarks

12.8 References

13 Key Indicator and Targets

13.1 Introduction

13.2 Key Indicators Represent Operation Opportunities

13.2.1 Reaction and Separation Optimization

13.2.2 Heat Exchanger Fouling Mitigation

13.2.3 Furnace Operation Optimization

13.2.4 Rotating Equipment Operation

13.2.5 Minimizing Steam Letdown Flows

13.2.6 Turndown Operation

13.3 Defining Key Indicators

13.3.1 Simplifying the Problem

13.3.2 Developing Key Indicators for the Reaction Section

13.3.3 Developing Key Indicators for the Product Fractionation Section

13.4 Set Up Targets for Key Indicators

13.5 Economic Evaluation for Key Indicators

13.6 Application 1: Implementing Key Indicators into an “Energy Dashboard”

13.7 Application 2: Implementing Key Indicators to Controllers

13.8 It is Worth the Effort

13.9 References

14 Distillation System Optimization

14.1 Introduction

14.2 Tower Optimization Basics

14.2.1 What to Watch: Key Operating Parameters

14.2.2 What Effects to Know: Parameter Relationship

14.2.3 What to Change: Parameter Optimization

14.2.4 Relax Soft Constraints to Improve Margin

14.3 Energy Optimization for Distillation System

14.4 Overall Process Optimization

14.5 Concluding Remarks

14.6 References

15 Fractionation and Separation Theory and Practice

15.1 Introduction

15.2 Separation Technology Overview

15.3 Distillation Basics

15.3.1 Difficulty of Separation

15.3.2 Selection of Operating Pressure

15.3.3 Types of Reboiler Configurations

15.3.4 Optimization of Design

15.3.5 Side Products

15.4 Advanced Distillation Topics

15.4.1 Heavy Oil Distillation

15.4.2 Dividing Wall Column DWC Fundamentals Guidelines for Using DWC Technology Application of Dividing Wall Column

15.4.3 Choice of Column Internals

15.4.4 Limitations with Distillation

15.5 Adsorption

15.6 Simulated Moving Bed

15.6.1 The Concept of Moving Bed

15.6.2 The Concept of Simulated Moving Bed

15.6.3 Rotary Valve

15.7 Crystallization

15.8 Liquid-Liquid Extraction

15.9 Extractive Distillation

15.10 Membranes

15.11 Selecting a Separation Method

15.12 References

16 Reaction Engineering Basics

16.1 Introduction

16.2 Reaction Basics

16.3 Reaction Kinetics Modeling Basics

16.4 Rate Equation Based on Surface Kinetics

16.5 Limitations in Catalytic Reaction

16.5.1 External Diffusion Limitation

16.5.2 Surface Reaction Limitation

16.5.3 Internal Pore Diffusion Limitation

16.5.4 Mitigating Limitations

16.5.5 Important Parameters of Limiting Reaction

16.6 Reactor Types

16.6.1 General Classification

16.7 Reactor Design

16.7.1 Objective

16.7.2 Temperature and Equilibrium Constant

16.7.3 Pressure, Reaction Conversion, and Selectivity

16.7.4 Reaction Time and Reactor Size

16.7.5 Determine the Rate-Limiting Step

16.7.6 Reactor Design Considerations

16.7.7 General Guidelines

16.8 Hybrid Reaction and Separation

16.9 Catalyst Deactivation: Root Causes and Modeling

16.10 References

Part 5: Operational Guidelines and Troubleshooting

17 Common Operating Issues

17.1 Introduction

17.2 Startup Considerations

17.2.1 Catalyst Reduction

17.2.2 Catalyst Sulfiding

17.2.3 Catalyst Attenuation

17.3 Methyl Group and Phenyl Ring Losses

17.4 Limiting Aromatics Losses

17.4.1 Olefin Removal in an Aromatics Complex

17.4.2 Fractionation and Separation Losses Vent Losses Losses to Distillate Liquid Product Losses to Bottoms Liquid Product

17.4.3 Extraction Losses Common Variables Affecting Aromatic Recovery Feed Composition Foaming

17.4.4 Reaction Losses Xylene Isomerization Unit Losses Transalkylation Unit Losses

17.4.5 Methyl Group Losses Fractionation and Separation Losses Reaction Losses

17.5 Fouling

17.5.1 Combine Feed Exchanger Fouling Chemical Foulants Particulate Foulants

17.5.2 Process Heat Exchanger Fouling

17.5.3 Heater Fouling

17.5.4 Specialty Reboiler Tube Fouling

17.5.5 Line Fouling

17.5.6 Extraction Unit Column Fouling

17.6 Aromatics Extraction Unit Solvent Degradation

17.6.1 Oxygen and Oxygenates

17.6.2 Temperature

17.6.3 Chloride

17.6.4 Other Measurements

17.7 Selective Adsorption of Para-Xylene by Simulated Moving Bed

17.7.1 Purity and Recovery Relationship

17.7.2 Meta-Xylene Contamination

17.7.3 Common Poisons Olefins Oxygenates Heavy Aromatics Water

17.7.4 Rotary Valve™ Monitoring Dome Pressure Alignment Maintenance

17.7.5 Flow Meter Monitoring

17.7.6 Hydration Monitoring

17.7.7 Shutdown and Restart Consideration Severe Startup or Shutdown Conditions Oxygenate Ingress Leaking of Adsorption Section Isolation Valves

17.8 Common Issues with Sampling and Laboratory Analysis

17.8.1 Bromine Index Analysis for Olefin Measurement

17.8.2 Atmospheric Contamination of Samples

17.8.3 Analysis of Unstabilized Liquid Samples

17.8.4 Gas Chromatography Nitrogen vs Hydrogen or Helium Carrier Gas Resolution of Meta-Xylene and Para-Xylene Peaks Wash Solvent Interference Over-Reliance on a Particular Analytical Method Impact of Unidentified Components

17.9 Measures of Operating Efficiency in Aromatics Complex Process Units

17.9.1 Selective Adsorption Para-Xylene Separation Unit

17.9.2 Xylene Isomerization Unit

17.9.3 Transalkylation Unit

17.9.4 Aromatics Extraction Unit

17.10 The Future of Plant Troubleshooting and Optimization

17.11 References

18 Troubleshooting Case Studies

18.1 Introduction

18.2 Transalkylation Unit – Low Catalyst Activity During Normal Operation

18.2.1 Summary of Symptoms

18.2.2 Root Cause and Solution

18.2.3 Lesson Learned

18.3 Xylene Isomerization Unit – Low Catalyst Activity Following Startup

18.3.1 Summary of Symptoms

18.3.2 Root Cause and Solution

18.3.3 Lesson Learned

18.4 Para-Xylene Selective Adsorption Unit – Low Recovery After Turnaround

18.4.1 Summary of Symptoms

18.4.2 Root Cause and Solution

18.4.3 Lesson Learned

18.5 Aromatics Extraction Unit – Low Extract Purity/Recovery

18.5.1 Summary of Symptoms

18.5.2 Root Cause and Solution

18.5.3 Lesson Learned

18.6 Aromatics Complex – Low Para-Xylene Production

18.6.1 Summary of Symptoms

18.6.2 Root Cause and Solution

18.6.3 Lesson Learned

18.7 Closing Remarks

18.8 References