Petroleum Refining Design and Applications Handbook, Volume 1

There is a renaissance that is occurring in chemical and process engineering, and it is crucial for today's scientists, engineers, technicians, and operators to stay current. With so many changes over the last few decades in equipment and processes, petroleum refining is almost a living document, constantly needing updating. With no new refineries being built, companies are spending their capital re-tooling and adding on to existing plants. Refineries are like small cities, today, as they grow bigger and bigger and more and more complex. A huge percentage of a refinery can be changed, literally, from year to year, to account for the type of crude being refined or to integrate new equipment or processes.

This book is the most up-to-date and comprehensive coverage of the most significant and recent changes to petroleum refining, presenting the state-of-the-art to the engineer, scientist, or student. Useful as a textbook, this is also an excellent, handy go-to reference for the veteran engineer, a volume no chemical or process engineering library should be without. Written by one of the world's foremost authorities, this book sets the standard for the industry and is an integral part of the petroleum refining renaissance. It is truly a must-have for any practicing engineer or student in this area.

Preface xix

Acknowledgments xxi

About the Author xxiii

1 Introduction 1

References 6

2 Composition of Crude Oils and Petroleum Products 7

2.1 Hydrocarbons 8

2.1.1 Alkynes Series 12

2.2 Aromatic Hydrocarbons 14

2.3 Heteroatomic Organic Compounds 15

2.3.1 Non-Hydrocarbons 15

2.3.2 Sulfur Compounds 18

2.4 Thiols 18

2.5 Oxygen Compounds 20

2.6 Nitrogen Compounds 22

2.7 Resins and Asphaltenes 23

2.8 Salts 24

2.9 Carbon Dioxide 24

2.10 Metallic Compounds 24

2.11 Products Composition 25

2.11.1 Liquefied Petroleum Gas (LPG) (C₃ and C₄) 26

2.11.2 Gasoline (C₅ to C₁₁) 26

2.11.3 Condensate (C₄, C₅ and C₆ >) 27

2.11.4 Gas Fuel Oils (C₁₂ to C₁₉) 27

2.11.5 Kerosene 27

2.11.6 Diesel Fuel 28

2.11.7 Fuel Oils # 4, 5, and 6 28

2.11.8 Residual Fuel Oil 28

2.11.9 Natural Gas 29

References 30

3 Characterization of Petroleum and Petroleum Fractions 31

3.1 Introduction 31

3.1.1 Crude Oil Properties 32

3.1.2 Gravity, API 32

3.1.3 Boiling Point Range 33

3.1.4 Characterization Factor 33

3.1.5 The Universal Oil Product Characterization factor, K_UOP 34

3.1.6 Carbon Residue, wt% 34

3.1.7 Nitrogen Content, wt% 36

3.1.8 Sulfur Content, wt% 36

3.1.9 Total Acid Number (TAN) 36

3.1.10 Salt Content, pounds/1000 barrels 36

3.1.11 Metals, parts/million (ppm) by weight 36

3.1.12 Pour Point (^oF or ^°C) 36

3.2 Crude Oil Assay Data 37

3.2.1 Whole crude oil average properties 37

3.2.2 Fractional properties 37

3.3 Crude Cutting Analysis 37

3.4 Crude Oil Blending 37

3.5 Laboratory Testing of Crude Oils 46

3.5.1 True Boiling Point (TBP) Curve 46

3.5.2 ASTM D86 Distillation 46

3.5.3 Boiling Points 47

3.5.4 Conversion Between ASTM and TBP Distillation 49

3.5.5 Petroleum Pseudo-Components 54

3.5.6 Pseudo-Component Normal Boiling Points 55

3.5.7 ASTM D1160 Distillation 55

3.5.8 Determination of ASTM IBP, 10%, 20–90% Points of Blend 55

3.5.9 ASTM 10–90% Points 56

3.5.10 Initial Boiling Point Determination 56

3.5.11 ASTM End Point of Blend 56

3.5.12 Flash Point 56

3.5.13 Flash Point, ^°F, as a Function of Average Boiling Point 57

3.5.14 Smoke Point of Kerosenes 57

3.5.15 Luminometer Number 57

3.5.16 Reid Vapor Pressure (RVP) 57

3.5.17 Vapor Pressure of Narrow Hydrocarbon Cuts 58

3.6 Octanes 58

3.7 Cetanes 58

3.7.1 Cetane Index 59

3.8 Diesel Index 59

3.9 Determination of the Lower Heating Value of Petroleum Fractions 59

3.10 Aniline Point Blending 60

3.11 Correlation Index (CI) 60

3.12 Chromatographically Simulated Distillations 61

4 Thermodynamic Properties of Petroleum and Petroleum Fractions 63

4.1 K-Factor Hydrocarbon Equilibrium Charts 64

4.2 Non-Ideal Systems 72

4.3 Vapor Pressure 74

4.3.1 Vapor Pressure Determination using the Clausius-Clapeyron and the Antoine Equations 75

4.4 Viscosity 80

4.4.1 Conversion to Saybolt Universal Viscosity 80

4.4.2 Conversion to Saybolt Furol Viscosity 82

4.4.3 Equivalents of Kinematic (cSt), Saybolt Universal (SUS), and Dynamic viscosity 82

4.4.4 Viscosity of Liquid Hydrocarbons 83

4.4.5 Gas Viscosity 84

4.5 Refractive Index 87

4.6 Liquid Density 89

4.6.1 Gas Density 89

4.7 Molecular Weight 90

4.8 Molecular Type Composition 90

4.9 Critical Temperature, T_c 96

4.10 Critical Pressure, P_c 97

4.11 Pseudo-Critical Constants and Acentric Factors 98

4.12 Enthalpy of Petroleum Fractions 99

4.13 Compressibility Z Factor of Natural Gases 100

4.14 Simulation Thermodynamic Software Programs 105

References 110

5 Process Descriptions of Refinery Processes 111

5.1 Introduction 111

5.2 Refinery and Distillation Processes 115

5.3 Process Description of the Crude Distillation Unit 120

5.3.1 Crude Oil Desalting 121

5.3.2 Types of Salts in Crude Oil 122

5.3.3 Desalting Process 122

5.3.4 Pumparound Heat Removal 127

5.3.5 Tower Pressure Drop and Flooding 130

5.3.6 Carbon Steel Trays 130

5.3.7 Rectifying Section of the Main Column 130

5.3.8 Side Stripping Columns 130

5.3.9 Crude Column Overhead 130

5.3.10 General Properties of Petroleum Fractions 130

5.4 Process Variables in the Design of Crude Distillation Column 132

5.4.1 Process Design of a Crude Distillation Column 133

5.5 Process Simulation 134

5.5.1 Overall Check of Simulation 135

5.5.2 Other Aspects of Design 136

5.5.3 Relationship between Actual Trays and Theoretical Trays 137

5.6 Process Description of Light Arabian Crude Using UniSim^® Simulation Software [12] 138

5.6.1 Column Conventions 141

5.6.2 Performance Specifications Definition 142

5.6.3 Cut Points 142

5.6.4 Degree of Separation 142

5.6.5 Overflash 142

5.6.6 Column Pressure 143

5.6.7 Overhead Temperature 143

5.6.8 Bottom Stripping 144

5.6.9 Side Stream Stripper 144

5.6.10 Reflux 144

5.7 Troubleshooting Actual Columns 144

5.8 Health, Safety and Environment Considerations 145

References 148

6 Thermal Cracking Processes 149

6.1 Process Description 152

6.2 Steam Jet Ejector 152

6.3 Pressure Survey in a Vacuum Column 154

6.4 Simulation of Vacuum Distillation Unit 156

6.5 Coking 157

6.5.1 Delayed Coking 157

6.5.2 Delayed Coker Yield Prediction 161

6.5.3 Coke Formation 162

6.5.4 Thermodynamics of Coking of Light Hydrocarbons 162

6.5.5 Gas Composition 163

6.6 Fluid Coking 164

6.6.1 Flexi-Coking 165

6.6.2 Contact Coking 167

6.6.3 Coke Drums 168

6.6.4 Heavy Coker Gas Oil (HCGO) Production 170

6.6.5 Light Coker Gas Oil (LCGO) Production 170

6.7 Fractionator Overhead System 170

6.8 Coke Drum Operations 172

6.9 Hydraulic Jet Decoking 173

6.10 Uses of Petroleum Coke 174

6.11 Use of Gasification 174

6.12 Sponge Coke 175

6.13 Safety and Environmental Considerations 175

6.14 Simulation/Calculations 176

6.15 Visbreaking 177

6.15.1 Visbreaking Reactions 180

6.15.2 Visbreaking Severity 180

6.15.3 Operation and Control 180

6.15.4 Typical Visbreaker Unit 181

6.15.5 Typical Visbreaker Unit with Vacuum Flasher 182

6.15.6 Typical Combination Visbreaker and Thermal Cracker 183

6.15.7 Product Yield 183

6.16 Process Simulation 184

6.17 Health, Safety and Environment Considerations 185

7 Hydroprocessing 187

7.1 Catalytic Conversion Processes 187

7.1.1 Hydrocracking Chemistry 188

7.1.2 Hydrocracking Reactions 190

7.1.3 Typical Hydrocracking Reactions 191

7.2 Feed Specifications 194

7.2.1 Space Velocity 195

7.2.2 Reactor Temperature 195

7.2.3 Reactor Pressure 195

7.2.4 Hydrogen Recycle Rate 195

7.2.5 Oil Recycle Ratio 195

7.2.6 Heavy Polynuclear Aromatics 196

7.3 Feed Boiling Range 196

7.4 Catalyst 196

7.4.1 Catalyst Performance 197

7.4.2 Loss of Catalyst Performance 197

7.4.3 Poisoning by Impurities in Feeds or Catalysts 198

7.4.4 The Apparent Catalyst Activity 200

7.5 Poor Gas Distribution 200

7.6 Poor Mixing of Reactants 200

7.7 The Mechanism of Hydrocracking 200

7.8 Thermodynamics and Kinetics of Hydrocracking 201

7.9 Process Design, Rating and Performance 204

7.9.1 Operating Temperature and Pressure 205

7.9.2 Optimum Catalyst Size and Shape 205

7.9.3 Pressure Drop (ΔP) in Tubular/Fixed-Bed Reactors 205

7.9.4 Catalyst Particle Size 207

7.9.5 Vessel Dimensions 208

7.10 Increased ΔP 210

7.11 Factors Affecting Reaction Rate 214

7.12 Measurement of Performance 215

7.13 Catalyst-Bed Temperature Profiles 216

7.14 Factors Affecting Hydrocracking Process Operation 217

7.15 Hydrocracking Correlations 217

7.15.1 Maximum Aviation Turbine Kerosene (ATK) Correlations 219

7.15.2 Process Description 220

7.15.3 Fresh Feed and Recycle Liquid System 224

7.15.4 Liquid and Vapor Separators 225

7.15.5 Recycle Gas Compression and Distribution 226

7.15.6 Hydrogen Distribution 226

7.15.7 Control of the Hydrogen System 226

7.15.8 Reactor Design 227

7.16 Hydrocracker Fractionating Unit 228

7.16.1 Mild Vacuum Column 230

7.16.2 Steam Generation 230

7.17 Operating Variables 231

7.18 Hydrotreating Process 234

7.18.1 Process Description 237

7.18.2 Process Variables 237

7.18.3 Hydrotreating Catalysts 240

7.19 Thermodynamics of Hydrotreating 240

7.20 Reaction Kinetics 243

7.21 Naphtha Hydrotreating 245

7.21.1 Hydrotreating Correlations 245

7.21.2 Middle Distillates Hydrotreating 248

7.21.3 Middle Distillate Hydrotreating Correlations 248

7.22 Atmospheric Residue Desulfurization 250

7.22.1 High-Pressure Separator 252

7.22.2 Low-Pressure Separator 252

7.22.3 Hydrogen Sulfide Removal 252

7.22.4 Recycled Gas Compressor 252

7.22.5 Process Water 252

7.22.6 Fractionation Column 253

7.22.7 Operating Conditions of Hydrotreating Processes 253

7.23 Health, Safety and Environment Considerations 258

References 258

8 Catalytic Cracking 259

8.1 Introduction 259

8.2 Fluidized Bed Catalytic Cracking 262

8.2.1 Process Description 262

8.3 Modes of Fluidization 269

8.4 Cracking Reactions 270

8.4.1 Secondary Reactions 272

8.5 Thermodynamics of FCC 273

8.5.1 Transport Phenomena, Reaction Patterns and Kinetic models 273

8.5.2 Three- and Four-Lump kinetic models 276

8.6 Process Design Variables 278

8.6.1 Process Variables 279

8.6.2 Process Operational Variables 280

8.7 Material and Energy Balances 281

8.7.1 Material Balance 281

8.7.2 Energy Balance 282

8.8 Heat Recovery 283

8.9 FCC Yield Correlations 284

8.10 Estimating Potential Yields of FCC Feed 286

8.11 Pollution Control 290

8.12 New Technology 292

8.12.1 Deep Catalytic Cracking 293

8.12.2 Shell’s Fluid Catalytic Cracking 294

8.12.3 Fluid Catalytic Cracking High Severity 295

8.12.4 Fluid Catalytic Cracking for Maximum Olefins 295

8.13 Refining/Petrochemical Integration 296

8.14 Metallurgy 296

8.15 Troubleshooting for Fluidized Catalyst Cracking Units 297

8.16 Health, Safety and Environment Considerations 298

8.17 Licensors’ Correlations 299

8.18 Simulation and Modeling Strategy 300

9 Catalytic Reforming and Isomerization 305

9.1 Introduction 305

9.2 Catalytic Reforming 306

9.3 Feed Characterization 306

9.4 Catalytic Reforming Processes 308

9.4.1 Role of Reformer in the Refinery 309

9.4.2 UOP Continuous Catalytic Regeneration (CCR) Reforming Process 310

9.5 Operations of the Reformer Process 312

9.5.1 Effect of Major Variables in Catalytic Reforming 314

9.6 Catalytic Reformer Reactors 316

9.7 Material Balance in Reforming 317

9.8 Reactions 320

9.8.1 Naphthene Dehydrogenation to Cyclohexanes 320

9.8.2 Dehydrocyclization of Paraffins to Aromatics 321

9.8.3 Dehydroisomerization of Alkylcyclopentanes to Aromatics 321

9.8.4 Isomerization of n-Paraffins 321

9.9 Hydrocracking Reactions 322

9.10 Reforming Catalyst 322

9.11 Coke Deposition 324

9.12 Thermodynamics 326

9.13 Kinetic Models 326

9.14 The Reactor Model 326

9.15 Modeling of Naphtha Catalytic Reforming Process 329

9.16 Isomerization 329

9.16.1 Thermodynamics 330

9.16.2 Isomerization Reactions 331

9.17 Sulfolane Extraction Process 331

9.17.1 Sulfolane Extraction Unit (SEU) Corrosion Problems 332

9.17.2 Other Solvents for the Extraction Unit 333

9.18 Aromatic Complex 333

9.18.1 Aromatic Separation 335

9.19 Hydrodealkylation Process 336

9.19.1 Separation of the Reactor Effluents 337

10 Alkylation and Polymerization Processes 339

10.1 Introduction 339

10.2 Chemistry of Alkylation 340

10.3 Catalysts 342

10.4 Process Variables 343

10.5 Alkylation Feedstocks 345

10.6 Alkylation Products 346

10.7 Sulfuric Acid Alkylation Process 346

10.8 HF Alkylation 347

10.9 Kinetics and Thermodynamics of Alkylation 351

10.10 Polymerization 354

10.11 HF and H₂SO₄ Mitigating Releases 354

10.12 Corrosion Problems 356

10.13 A New Technology of Alkylation Process Using Ionic Liquid 356

10.14 Chevron – Honeywell UOP Ionic liquid Alkylation 357

10.15 Chemical Release and Flash Fire: A Case Study of the Alkylation Unit at the Delaware City Refining Company (DCRC) Involving Equipment Maintenance Incident 358

References 362

11 Hydrogen Production and Purification 365

11.1 Hydrogen Requirements in a Refinery 365

11.2 Process Chemistry 366

11.3 High-Temperature Shift Conversion 368

11.4 Low-Temperature Shift Conversion 368

11.5 Gas Purification 368

11.6 Purification of Hydrogen Product 369

11.7 Hydrogen Distribution System 370

11.8 Off-Gas Hydrogen Recovery 371

11.9 Pressure Swing Adsorption (PSA) Unit 371

11.10 Refinery Hydrogen Management 375

11.11 Hydrogen Pinch Studies 377

References 379

12 Gas Processing and Acid Gas Removal 381

12.1 Introduction 381

12.2 Diesel Hydrodesulfurization (DHDS) 383

12.3 Hydrotreating Reactions 383

12.4 Gas Processing 388

12.4.1 Natural Gas 388

12.4.2 Gas Processing Methods 389

12.4.3 Reaction Gas Processes 390

12.4.4 Sweetening Process 390

12.4.5 MEROX Process 390

12.5 Sulfur Management 391

12.5.1 Sulfur Recovery Processes 393

12.5.2 Tail Gas Clean Up 401

12.6 Physical Solvent Gas Processes 401

12.6.1 Physical and Chemical Processes 402

12.6.2 Advantages and Disadvantages of the Sulfinol^® Process 402

12.7 Carbonate Process 402

12.8 Solution Batch Process 403

12.9 Process Description of Gas Processing using UniSim^® Simulation 405

12.10 Gas Dryer (Dehydration) Design 410

12.10.1 The Equations 412

12.10.2 Pressure Drop (ΔP) 413

12.10.3 Fouled Bed 413

12.11 Kremser-Brown-Sherwood Method-No Heat of Absorption 415

12.11.1 Absorption: Determine Component Absorption in Fixed Tray Tower (Adapted in part from Ref. 12) 415

12.11.2 Absorption: Determine the Number of Trays for Specified Product Absorption 417

12.11.3 Stripping: Determine the Number of Theoretical Trays and Stripping Steam or Gas Rate for a Component Recovery 418

12.11.4 Stripping: Determine Stripping-Medium Rate for a Fixed Recovery 420

12.12 Absorption: Edmister Method 421

12.12.1 Absorption and Stripping Efficiency 427

12.13 Gas Treating Troubleshooting 432

12.13.1 High Exit Gas Dew Point 432

12.13.2 High Glycol Losses 432

12.13.3 Glycol Contamination 432

12.13.4 Poor Glycol Reconcentration 433

12.13.5 Low Glycol Circulation – Glycol Pump 433

12.13.6 High Pressure Drop Across Contactor 433

12.13.7 High Stripping Still Temperature 433

12.13.8 High Reboiler Pressure 433

12.13.9 Firetube Fouling/Hot Spots/Burn Out 433

12.13.10 High Gas Dew Points 433

12.13.11 Cause – Inadequate Glycol Circulation Rate 433

12.13.12 Low Reboiler Temperature 433

12.13.13 Flash Separator Failure 434

12.13.14 Cause – Insufficient Reconcentration of Glycol 434

12.13.15 Cause – Operating Conditions Different from Design 434

12.13.16 Cause – Low Gas Flow Rates 434

12.13.17 High Glycol Loss 434

12.14 Cause – Loss of Glycol Out of Still Column 434

12.15 The ADIP Process 435

12.16 Sour Water Stripping Process 435

Glossary of Petroleum and Technical Terminology 441

Appendix A Equilibrium K values 533

Appendix B Analytical Techniques 547

Appendix C Physical and Chemical Characteristics of Major Hydrocarbons 557

Appendix D A List of Engineering Process Flow Diagrams and Process Data Sheets 573

Index 623

Kayode Coker PhD, is Engineering Consultant for AKC Technology, an Honorary Research Fellow at the University of Wolverhampton, U.K., a former Engineering Coordinator at Saudi Aramco Shell Refinery Company and Chairman of the department of Chemical Engineering Technology at Jubail Industrial College, Saudi Arabia. He has been a chartered chemical engineer for more than 30 years. He is a Fellow of the Institution of Chemical Engineers, U.K. and a senior member of the American Institute of Chemical Engineers. He holds a B.Sc. honors degree in Chemical Engineering, a Master of Science degree in Process Analysis and Development and Ph.D. in Chemical Engineering, all from Aston University, Birmingham, U.K. and a Teacher's Certificate in Education at the University of London, U.K. He has directed and conducted short courses extensively throughout the world and has been a lecturer at the university level. His articles have been published in several international journals. He is an author of five books in chemical engineering, a contributor to the Encyclopedia of Chemical Processing and Design. Vol 61. He was named as one of the International Biographical Centre's Leading Engineers of the World for 2008. Also, he is a member of International Who's Who of ProfessionalsTM and Madison Who's Who in the U.S.