Preface ......................................................... v
1 Heavy Oil and Residue Properties and Composition ............. 1
1.1 Definition of Petroleum Residues, Heavy Oils, and
Bitumens ................................................ 1
1.2 Physical Properties ..................................... 2
1.2.1 Hydrogen to carbon ratio ......................... 4
1.2.2 Heteroatom content ............................... 5
1.2.3 Class fractionation .............................. 6
1.2.4 Boiling cuts ..................................... 8
1.2.5 Other properties ................................ 16
1.3 Chemical Composition of Residues
1.3.1 Hydrocarbon groups .............................. 16
1.3.2 Heteroatomic groups ............................. 18
1.3.3 Asphaltene composition and structure ............ 22
1.4 Chemical Analysis of Residues .......................... 23
1.4.1 Chemical group analysis by NMR .................. 26
1.4.2 Average molecular weight and molecular weight
distribution .................................... 31
1.4.3 Mass spectrometry of residues ................... 34
1.5 Environmental Properties of Heavy Oils and Residues .... 35
1.5.1 Acute toxicity .................................. 35
1.5.2 Mutagenicity and carcinogenicity ................ 36
1.6 Product Specifications for Bitumen, Heavy Oil, and
Residue ................................................ 37
Notation ............................................... 39
Problems ............................................... 39
2 Thermodynamic and Transport Properties of Heavy Oil and
Bitumen ..................................................... 41
2.1 Equations of State for Hydrocarbon Mixtures ............ 41
2.1.1 Cubic equations of state ........................ 42
2.1.2 Mixing rules for cubic equations ................ 44
2.2 Phase Behavior of Undefined Mixtures ................... 45
2.3 Measurement of Oil Distillation Chacteristics .......... 46
2.3.1 Batch distillation .............................. 46
2.3.2 Simulated distillation .......................... 48
2.3.3 True boiling point (TBP) distillation ........... 52
2.3.4 Equilibrium flash vaporization (EFV) curves ..... 52
2.3.5 Conversion of ASTM boiling point data to true
boiling points .................................. 52
2.3.6 Specific gravity ................................ 55
2.4 Calculation of Mean Boiling Points ..................... 55
2.5 Estimation of Critical Properties ...................... 58
2.5.1 Critical temperature ............................ 60
2.5.2 Critical volume ................................. 60
2.5.3 Critical pressure ............................... 60
2.5.4 Molecular weight ................................ 61
2.5.5 Acentric factor ................................. 61
2.6 Selection of Pseudocomponents .......................... 62
2.7 Critical Properties of Residue Fractions ............... 64
2.7.1 Single pseudocomponent .......................... 64
2.7.2 Multiple pseudocomponents by extrapolation ...... 65
2.7.3 Chemical characterization of residue ............ 66
2.8 Hydrogen Solubility .................................... 68
2.9 Precipitation of Solids ................................ 69
2.10 Thermal Properties of Petroleum Fractions .............. 73
2.11 Surface Tension ........................................ 74
2.12 Transport Properties ................................... 75
2.12.1 Viscosity ....................................... 75
2.12.1 Thermal conductivity ............................ 78
2.12.2 Diffusivity ..................................... 79
Notation ............................................... 79
Problems ............................................... 81
3 Chemistry of Upgrading and Hydrotreating Reactions .......... 83
3.1 Overall Objectives of Primary Upgrading ................ 83
3.2 Thermal Reactions ...................................... 84
3.2.1 Carbon-carbon bond breakage ..................... 84
3.2.2 Limits on catalytic C-C bond breakage in
residues ........................................ 85
3.2.3 Cracking of paraffins ........................... 86
3.2.4 Further reactions of olefins .................... 90
3.2.5 Reactions of naphthenes ......................... 91
3.2.6 Reactions of alkylaromatics and aromatics ....... 93
3.2.7 Reactions of bridged aromatics .................. 94
3.2.8 Example: Cracking of a hypothetical residue
molecule ........................................ 95
3.2.9 Reactions of mixtures ........................... 97
3.2.10 Sulfur compounds ................................ 97
3.3 Catalytic Reactions .................................... 98
3.3.1 Catalyst composition ............................ 98
3.3.2 Reactions of aromatic compounds ................. 99
3.3.3 Reactions of sulfur, nitrogen, and oxygen
compounds ...................................... 104
3.3.4 Demetallization reactions ...................... 108
3.3.5 Catalytic C-C bond breakage in distillates ..... 108
3.4 Interactions Between Catalytic and Thermal
Reactions ............................................. 111
3.4.1 Mechanisms of thermal and catalytic
interactions ................................... 111
3.4.2 Reaction scheme for residue conversion ......... 113
Notation .............................................. 115
Problems .............................................. 115
4 Fundamentals for Kinetic Analysis of Upgrading Reactions ... 116
4.1 Thermal Reactions ..................................... 116
4.1.1 Example of thermal cracking: Kinetics for
cracking of n-hexadecane ....................... 119
4.1.2 Cracking of mixtures ........................... 122
4.2 Catalytic Reactions ................................... 126
4.2.1 Catalytic kinetics ............................. 126
4.2.2 Steady-state kinetics of catalytic reactions ... 134
4.2.3 Kinetics of reversible reactions ............... 139
4.3 Mass Transfer and Catalytic Reactions ................. 143
4.3.1 Hindered diffusion in porous catalysts ......... 143
4.3.2 Catalyst effectiveness due to internal
diffusion ...................................... 149
4.3.3 External mass transfer resistances ............. 154
4.4 Lumping of Complex Reaction Mixtures .................. 159
4.4.1 Desulfurization of gas oil in a PFR ............ 163
4.4.2 Desulfurization of gas oil in a CSTR ........... 164
4.4.3 Limits to fractional order for mixture
reactions ...................................... 170
4.4.4 Error in lumping a distribution of reaction
rates .......................................... 171
4.4.5 Activation energy of lumped reactions ........... 178
Notation .............................................. 179
5 Residue Hydroconversion Processes .......................... 182
5.1 Introduction .......................................... 182
5.2 Fixed-Bed Catalytic Processes ......................... 184
5.3 Catalytic Ebullated Bed Processes ..................... 186
5.3.1 Moderate conversion of residue ................. 186
5.3.2 Processing for high conversion of residue ...... 191
5.3.3 Reactor hydrodynamics .......................... 191
5.4 Catalyst Deactivation ................................. 193
5.4.1 Coke deposition on residue conversion
catalysts ...................................... 193
5.4.2 Metal deposition on residue conversion
catalysts ...................................... 195
5.4.3 Kinetics of deactivation of demetallization
catalyst ....................................... 197
5.4.4 Activity as a function of time-on-stream ....... 200
5.4.5 Catalyst regeneration .......................... 203
5.5 Additive-Based Processes .............................. 205
5.5.1 Process description ............................ 205
5.5.2 Reactor hydrodynamics .......................... 209
5.6 Sediment formation .................................... 209
5.7 Kinetics of Hydroconversion Reactions ................. 215
5.7.1 Residue conversion ............................. 215
5.7.2 Kinetics of sulfur removal ..................... 223
5.7.3 Uptake of hydrogen ............................. 226
5.7.4 Kinetics of nitrogen and metals removal ........ 227
5.7.5 Kinetics of heat release ....................... 227
5.8 Hydroconversion Preprocesses and Modifications ........ 228
5.8.1 Solvent deasphalting ............................ 228
5.8.2 Low-temperature hydrogenation .................. 228
5.8.3 Coprocessing of residue and coal ............... 229
5.9 Environmental Aspects of Residue Hydroconversion ...... 230
Notation .............................................. 231
Problems .............................................. 232
6 Thermal and Coking Processes ............................... 237
6.1 Severity of Thermal Processes ......................... 237
6.2 Thermal Viscosity Reduction (Visbreaking) ............. 239
6.3 Delayed Coking ........................................ 244
6.4 Fluid Coking .......................................... 246
6.5 Coke Yields and Properties ............................ 251
6.6 Kinetics and Mechanism of Coke Formation .............. 253
6.7 Integration of Coking and Hydroconversion Processes ... 257
6.8 Environmental Aspects of Thermal Processes ............ 259
Notation .............................................. 260
Problems .............................................. 260
7 Fluid Catalytic Cracking of Residues ....................... 262
7.1 Process Description ................................... 262
7.1.1 Catalytic cracking chemistry ................... 262
7.1.2 Cracking in riser reactors ..................... 263
7.1.3 Catalyst compostion ............................ 267
7.1.4 Enthalpies and kinetics of FCC units ........... 267
7.2 Effects of Residue Feed on FCC Operation .............. 269
7.3 Catalyst Modifications for Residue FCC ................ 275
7.3.1 Metal-resistant catalysts ...................... 275
7.3.2 Trapping of sulfur ............................. 275
7.3.3 High-boiling feed .............................. 276
7.4 Process Modifications for Residue FCC ................. 277
7.4.1 Catalyst regeneration .......................... 277
7.4.2 Reactor modifications .......................... 278
7.4.3 Pretreatment of FCC feed ....................... 278
7.5 Environmental Aspects of Residue FCC .................. 280
Notation .............................................. 281
Problems .............................................. 282
8 Hydrotreating of Cracked Products .......................... 284
8.1 Properties of Feeds for Hydrotreating ................. 285
8.2 Characteristics of Cracked Distillates ................ 286
8.3 Process Description ................................... 286
8.4 Reaction Chemistry .................................... 291
8.4.1 Sulfur removal ................................. 291
8.4.2 Nitrogen removal ............................... 291
8.4.3 Oxygen removal ................................. 295
8.4.4 Hydrogen consumption and aromatics
conversion ..................................... 295
8.4.5 Relative removal of heteroatomic compounds ..... 295
8.4.6 Thermal reactions .............................. 298
8.5 Kinetics and Hydrodynamics of Hydrotreating ........... 298
8.5.1 Apparent reaction order and kinetics ........... 298
8.5.2 Reactor hydrodynamics .......................... 301
8.5.3 Stoichiometry of hydrotreating ................. 304
8.6 Catalyst Properties ................................... 305
8.6.1 Catalyst selection ............................. 305
8.6.2 Catalyst deactivation .......................... 307
8.6.3 Regeneration of spent hydrotreating
catalysts ...................................... 314
8.7 Secondary Hydrotreating of Distillates ................. 314
Notation ...................................................... 317
Problems ...................................................... 318
References .................................................... 320
Index ......................................................... 339
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