Introduction to Catalysis and Industrial Catalytic Processes

Preface xv Acknowledgments xvii List of Figures xix Nomenclature xxvii Chapter 1 Catalyst Fundamentals of Industrial Catalysis 1 1.1 Introduction 1 1.2 Catalyzed versus Noncatalyzed Reactions 1 1.2.1 Example Reaction: Liquid-Phase Redox Reaction 2 1.2.2 Example Reaction: Gas-Phase Oxidation Reaction 4 1.3 Physical Structure of a Heterogeneous Catalyst 6 1.3.1 Active Catalytic Species 7 1.3.2 Chemical and Textural Promoters 7 1.3.3 Carrier Materials 8 1.3.4 Structure of the Catalyst and Catalytic Reactor 8 1.4 Adsorption and Kinetically Controlled Models for Heterogeneous Catalysis 10 1.4.1 Langmuir Isotherm 11 1.4.2 Reaction Kinetic Models 13 1.4.2.1 Langmuir–Hinshelwood Kinetics for CO Oxidation on Pt 14 1.4.2.2 Mars–van Krevelen Kinetic Mechanism 17 1.4.2.3 Eley–Rideal (E–R) Kinetic Mechanism 18 1.4.2.4 Kinetic versus Empirical Rate Models 18 1.5 Supported Catalysts: Dispersed Model 19 1.5.1 Chemical and Physical Steps Occurring during Heterogeneous Catalysis 19 1.5.2 Reactant Concentration Gradients within the Catalyzed Material 22 1.5.3 The Rate-Limiting Step 22 1.6 Selectivity 24 1.6.1 Examples of Selectivity Calculations for Reactions with Multiple Products 25 1.6.2 Carbon Balance 26 1.6.3 Experimental Methods for Measuring Carbon Balance 27 Questions 27 Bibliography 29 Chapter 2 The Preparation of Catalytic Materials 31 2.1 Introduction 31 2.2 Carrier Materials 32 2.2.1 Al2O3 32 2.2.2 SiO2 34 2.2.3 TiO2 34 2.2.4 Zeolites 35 2.2.5 Carbons 37 2.3 Incorporating the Active Material into the Carrier 37 2.3.1 Impregnation 37 2.3.2 Incipient Wetness or Capillary Impregnation 38 2.3.3 Electrostatic Adsorption 38 2.3.4 Ion Exchange 38 2.3.5 Fixing the Catalytic Species 39 2.3.6 Drying and Calcination 39 2.4 Forming the Final Shape of the Catalyst 40 2.4.1 Powders 40 2.4.1.1 Milling and Sieving 41 2.4.1.2 Spray Drying 42 2.4.2 Pellets, Pills, and Rings 43 2.4.3 Extrudates 43 2.4.4 Granules 44 2.4.5 Monoliths 44 2.5 Catalyst Physical Structure and Its Relationship to Performance 45 2.6 Nomenclature for Dispersed Catalysts 45 Questions 46 Bibliography 46 Chapter 3 Catalyst Characterization 48 3.1 Introduction 48 3.2 Physical Properties of Catalysts 49 3.2.1 Surface Area and Pore Size 49 3.2.1.1 Nitrogen Porosimetry 49 3.2.1.2 Pore Size by Mercury Intrusion 51 3.2.2 Particle Size Distribution of Particulate Catalyst 51 3.2.2.1 Particle Size Distribution 51 3.2.2.2 Mechanical Strength 53 3.2.3 Physical Properties of Environmental Washcoated Monolith Catalysts 54 3.2.3.1 Washcoat Thickness 54 3.2.3.2 Washcoat Adhesion 54 3.3 Chemical and Physical Morphology Structures of Catalytic Materials 54 3.3.1 Elemental Analysis 54 3.3.2 Thermal Gravimetric Analysis and Differential Thermal Analysis 55 3.3.3 The Morphology of Catalytic Materials by Scanning Electron Microscopy 56 3.3.4 Structural Analysis by X-Ray Diffraction 57 3.3.5 Structure and Morphology of Al2O3 Carriers 58 3.3.6 Dispersion or Crystallite Size of Catalytic Species 58 3.3.6.1 Chemisorption 58 3.3.6.2 Transmission Electron Microscopy 61 3.3.7 X-Ray Diffraction 62 3.3.8 Surface Composition of Catalysts by X-Ray Photoelectron Spectroscopy 62 3.3.9 The Bonding Environment of Metal Oxides by Nuclear Magnetic Resonance 64 3.4 Spectroscopy 65 Questions 66 Bibliography 67 Chapter 4 Reaction Rate in Catalytic Reactors 69 4.1 Introduction 69 4.2 Space Velocity, Space Time, and Residence Time 69 4.3 Definition of Reaction Rate 71 4.4 Rate of Surface Kinetics 72 4.4.1 Empirical Power Rate Expressions 72 4.4.2 Experimental Measurement of Empirical Kinetic Parameters 73 4.4.3 Accounting for Chemical Equilibrium in Empirical Rate Expression 77 4.4.4 Special Case for First-Order Isothermal Reaction 77 4.5 Rate of Bulk Mass Transfer 78 4.5.1 Overview of Bulk Mass Transfer Rate 78 4.5.2 Origin of Bulk Mass Transfer Rate Expression 79 4.6 Rate of Pore Diffusion 80 4.6.1 Overview of Pore Diffusion 80 4.6.2 Pore Diffusion Theory 81 4.7 Apparent Activation Energy and the Rate-Limiting Process 82 4.8 Reactor Bed Pressure Drop 83 4.9 Summary 84 Questions 84 Bibliography 87 Chapter 5 Catalyst Deactivation 88 5.1 Introduction 88 5.2 Thermally Induced Deactivation 88 5.2.1 Sintering of the Catalytic Species 89 5.2.2 Sintering of Carrier 92 5.2.3 Catalytic Species–Carrier Interactions 95 5.3 Poisoning 96 5.3.1 Selective Poisoning 96 5.3.2 Nonselective Poisoning or Masking 97 5.4 Coke Formation and Catalyst Regeneration 99 Questions 101 Bibliography 103 Chapter 6 Generating Hydrogen and Synthesis Gas by Catalytic Hydrocarbon Steam Reforming 104 6.1 Introduction 104 6.1.1 Why Steam Reforming with Hydrocarbons? 104 6.2 Large-Scale Industrial Process for Hydrogen Generation 105 6.2.1 General Overview 105 6.2.2 Hydrodesulfurization 106 6.2.3 Hydrogen via Steam Reforming and Partial Oxidation 106 6.2.3.1 Steam Reforming 106 6.2.3.2 Deactivation of Steam Reforming Catalyst 110 6.2.3.3 Pre-reforming 111 6.2.3.4 Partial Oxidation and Autothermal Reforming 111 6.2.4 Water Gas Shift 112 6.2.4.1 Deactivation of Water Gas Shift Catalyst 116 6.2.5 Safety Considerations During Catalyst Removal 116 6.2.6 Other CO Removal Methods 116 6.2.6.1 Pressure Swing Absorption 116 6.2.6.2 Methanation 117 6.2.6.3 Preferential Oxidation of CO 117 6.2.7 Hydrogen Generation for Ammonia Synthesis 119 6.2.8 Hydrogen Generation for Methanol Synthesis 120 6.2.9 Synthesis Gas for Fischer–Tropsch Synthesis 120 6.3 Hydrogen Generation for Fuel Cells 121 6.3.1 New Catalyst and Reactor Designs for the Hydrogen Economy 122 6.3.2 Steam Reforming 123 6.3.3 Water Gas Shift 124 6.3.4 Preferential Oxidation 125 6.3.5 Combustion 125 6.3.6 Autothermal Reforming for Complicated Fuels 126 6.3.7 Steam Reforming of Methanol: Portable Power Applications 126 6.4 Summary 126 Questions 127 Bibliography 128 Chapter 7 Ammonia, Methanol, Fischer–Tropsch Production 129 7.1 Ammonia Synthesis 129 7.1.1 Thermodynamics 129 7.1.2 Reaction Chemistry and Catalyst Design 130 7.1.3 Process Design 132 7.1.4 Catalyst Deactivation 134 7.2 Methanol Synthesis 134 7.2.1 Process Design 136 7.2.1.1 Quench Reactor 136 7.2.1.2 Staged Cooling Reactor 137 7.2.1.3 Tube-Cooled Reactor 137 7.2.1.4 Shell-Cooled Reactor 138 7.2.2 Catalyst Deactivation 139 7.3 Fischer–Tropsch Synthesis 140 7.3.1 Process Design 142 7.3.1.1 Bubble/Slurry-Phase Process 142 7.3.1.2 Packed Bed Process 143 7.3.1.3 Slurry/Loop Reactor (Synthol Process) 143 7.3.2 Catalyst Deactivation 143 Questions 144 Bibliography 145 Chapter 8 Selective Oxidations 146 8.1 Nitric Acid 146 8.1.1 Reaction Chemistry and Catalyst Design 146 8.1.1.1 The Importance of Catalyst Selectivity 147 8.1.1.2 The PtRh Alloy Catalyst 147 8.1.2 Nitric Acid Production Process 148 8.1.3 Catalyst Deactivation 150 8.2 Hydrogen Cyanide 151 8.2.1 HCN Production Process 152 8.2.2 Deactivation 152 8.3 The Claus Process: Oxidation of H2S 154 8.3.1 Clause Process Description 154 8.3.2 Catalyst Deactivation 155 8.4 Sulfuric Acid 155 8.4.1 Sulfuric Acid Production Process 155 8.4.2 Catalyst Deactivation 158 8.5 Ethylene Oxide 159 8.5.1 Catalyst 159 8.5.2 Catalyst Deactivation 160 8.5.3 Ethylene Oxide Production Process 160 8.6 Formaldehyde 160 8.6.1 Low-Methanol Production Process 162 8.6.1.1 Fe+Mo Catalyst 162 8.6.2 High-Methanol Production Process 163 8.6.2.1 Ag Catalyst 164 8.7 Acrylic Acid 164 8.7.1 Acrylic Acid Production Process 164 8.7.2 Acrylic Acid Catalyst 165 8.7.3 Catalyst Deactivation 166 8.8 Maleic Anhydride 166 8.8.1 Catalyst Deactivation 166 8.9 Acrylonitrile 166 8.9.1 Acrylonitrile Production Process 167 8.9.2 Catalyst 168 8.9.3 Deactivation 168 Questions 168 Bibliography 169 Chapter 9 Hydrogenation, Dehydrogenation, and Alkylation 171 9.1 Introduction 171 9.2 Hydrogenation 171 9.2.1 Hydrogenation in Stirred Tank Reactors 171 9.2.2 Kinetics of a Slurry-Phase Hydrogenation Reaction 174 9.2.3 Design Equation for the Continuous Stirred Tank Reactor 176 9.3 Hydrogenation Reactions and Catalysts 177 9.3.1 Hydrogenation of Vegetable Oils for Edible Food Products 177 9.3.2 Hydrogenation of Functional Groups 180 9.3.3 Biomass (Corn Husks) to a Polymer 183 9.3.4 Comparing Base Metal and Precious Metal Catalysts 183 9.4 Dehydrogenation 185 9.5 Alkylation 187 Questions 188 Bibliography 189 Chapter 10 Petroleum Processing 190 10.1 Crude Oil 190 10.2 Distillation 191 10.3 Hydrodemetalization and Hydrodesulfurization 193 10.4 Hydrocarbon Cracking 197 10.4.1 Fluid Catalytic Cracking 197 10.4.2 Hydrocracking 200 10.5 Naphtha Reforming 200 Questions 202 Bibliography 203 Chapter 11 Homogeneous Catalysis and Polymerization Catalysts 205 11.1 Introduction to Homogeneous Catalysis 205 11.2 Hydroformylation: Aldehydes from Olefins 206 11.3 Carboxylation: Acetic Acid Production 208 11.4 Enzymatic Catalysis 209 11.5 Polyolefins 210 11.5.1 Polyethylene 210 11.5.2 Polypropylene 212 Questions 213 Bibliography 213 Chapter 12 Catalytic Treatment from Stationary Sources: Hc, Co, Nox, and O3 215 12.1 Introduction 215 12.2 Catalytic Incineration of Hydrocarbons and Carbon Monoxide 216 12.2.1 Monolith (Honeycomb) Reactors 218 12.2.2 Catalyzed Monolith (Honeycomb) Structures 219 12.2.3 Reactor Sizing 220 12.2.4 Catalyst Deactivation 222 12.2.5 Regeneration of Deactivated Catalysts 224 12.3 Food Processing 225 12.3.1 Catalyst Deactivation 226 12.4 Nitrogen Oxide (NOx) Reduction from Stationary Sources 226 12.4.1 SCR Technology 227 12.4.2 Ozone Abatement in Aircraft Cabin Air 229 12.4.3 Deactivation 229 12.5 CO2 Reduction 230 Questions 231 Bibliography 233 Chapter 13 Catalytic Abatement of Gasoline Engine Emissions 235 13.1 Emissions and Regulations 235 13.1.1 Origins of Emissions 235 13.1.2 Regulations in the United States 236 13.1.3 The Federal Test Procedure for the United States 238 13.2 Catalytic Reactions Occurring During Catalytic Abatement 238 13.3 First-Generation Converters: Oxidation Catalyst 239 13.4 The Failure of Nonprecious Metals: A Summary of Catalyst History 240 13.4.1 Deactivation and Stabilization of Precious Metal Oxidation Catalysts 241 13.5 Supporting the Catalyst in the Exhaust 242 13.5.1 Ceramic Monoliths 242 13.5.2 Metal Monoliths 245 13.6 Preparing the Monolith Catalyst 246 13.7 Rate Control Regimes in Automotive Catalysts 247 13.8 Catalyzed Monolith Nomenclature 248 13.9 Precious Metal Recovery from Catalytic Converters 248 13.10 Monitoring Catalytic Activity in a Monolith 248 13.11 The Failure of the Traditional Beaded (Particulate) Catalysts for Automotive Applications 250 13.12 NOx, CO and HC Reduction: The Three-Way Catalyst 251 13.13 Simulated Aging Methods 255 13.14 Close-Coupled Catalyst 256 13.15 Final Comments 258 Questions 259 Bibliography 261 Chapter 14 Diesel Engine Emission Abatement 262 14.1 Introduction 262 14.1.1 Emissions from Diesel Engines 262 14.1.2 Analytical Procedures for Particulates 264 14.2 Catalytic Technology for Reducing Emissions from Diesel Engines 265 14.2.1 Diesel Oxidation Catalyst 265 14.2.2 Diesel Soot Abatement 266 14.2.3 Controlling NOx in Diesel Engine Exhaust 267 Questions 272 Bibliography 273 Chapter 15 Alternative Energy Sources Using Catalysis: Bioethanol by Fermentation, Biodiesel by Transesterification, and H2-Based Fuel Cells 274 15.1 Introduction: Sources of Non-Fossil Fuel Energy 274 15.2 Sources of Non-Fossil Fuels 276 15.2.1 Biodiesel 276 15.2.1.1 Production Process 276 15.2.2 Bioethanol 277 15.2.2.1 Process for Bioethanol from Corn 278 15.2.3 Lignocellulose Biomass 278 15.2.4 New Sources of Natural Gas and Oil Sands 279 15.3 Fuel Cells 279 15.3.1 Markets for Fuel Cells 281 15.3.1.1 Transportation Applications 281 15.3.1.2 Stationary Applications 282 15.3.1.3 Portable Power Applications 282 15.4 Types of Fuel Cells 283 15.4.1 Low-Temperature PEM Fuel Cell 284 15.4.1.1 Electrochemical Reactions for H2-Fueled Systems 284 15.4.1.2 Mechanistic Principles of the PEM Fuel Cell 286 15.4.1.3 Membrane Electrode Assembly 287 15.4.2 Solid Polymer Membrane 288 15.4.3 PEM Fuel Cells Based on Direct Methanol 289 15.4.4 Alkaline Fuel Cell 290 15.4.5 Phosphoric Acid Fuel Cell 290 15.4.6 Molten Carbonate Fuel Cell 291 15.4.7 Solid Oxide Fuel Cell 293 15.5 The Ideal Hydrogen Economy 293 Questions 294 Bibliography 295 Index 297