Process Chemistry of Petroleum Macromolecules

Process Chemistry of Petroleum Macromolecules

First Day

1.  Characterization of Heavy Oils………….…………………………………..1

a.  Class Separation: Saturates, Aromatics, Resins, Asphaltenes, & Coke 6

b.  Properties of Classes……………………………………………………...7

c.  Measurement of Asphaltene Molecular Weight………………………...8

d.  Concept of Asphaltenes…………………………………………………...9

e.  Solvent-Resid Phase Diagram…………………………………………...11

f.  Scattering Data on Classes………………………………………………12

A.  Evidence of Asphaltene Colloid…………………………………13

B.  Evidence of Asphaltene Association…………………………….13

g.  High Performance Liquid Chromatography (HPLC)…………………16

A.  Prep Separation of Heavy Coker Gas Oil (HKGO)……………18

B.  Representative HKGO Structures………………………………19

C.  Prep Separation of Distact Cut of Arabian Heavy Vac Resid…22

2.  Pendant-Core Building Block Model of Petroleum………………………...23

a.  Approximation to Distribution of Heavy Oil Molecules……………….35

b.  Model for Conradson Carbon Residue (CCR)…………...………….…36

A.  Related to Hydrogen Content………………………………...….36

B.  Evidence of Constant Core and Pendant……………………...... 37

C.  Effect of Molecular Weight…………………………………...….41

D.  Elemental Analysis of CCR (Cores)……………………………..42

E.  Elemental Analysis of Distillable Liq Products (Pendants)...… 44

F.  Variation with Processing……………………………………...... 46

c.  Pendant-Core Model Compounds: Discotic Liquid Crystals………….48

A.  Model of CCR and Association……………………...…………..48

B.  Effect of Multiple Bonds……………………………………..…..48

C.  Implication on CCR Conversion…………………………...……48

d.  Future Needs for Building Block Models……………………………….49

3.  Phase Behavior of Heavy Oils………………………………………………..50

a.  Causes of Incompatible Liquids……………………………………...….61

b.  Basic Features of Heavy Oil Phase Behavior………………………...…62

A.  Flocculation Point………………………………………………...63

B.  Asymptotic Quantity of Insolubles with Quant. of Nonsolvent..64

C.  Effect of n-Paraffin Nonsolvent Carbon Number………………65

i.  Asmptotic Quantity of Insolubles………………………..65

ii.  Maximum in Flocculation Point………………………....66

c.  Effect of Temperature……………………………………………………67

A.  Live Oils………………………………………………………...…67

B.  Dead Oils…………………………………………………………..68

d.  Solubility Parameters…………………………………………………….70

A.  Overall Solubility Parameter…………………………………….71

B.  Two-Dimensional Solubility Parameters…………………..……71

i.  Values for Liquids……………………………………..….72

ii.  Solubility Map for Coal Liquid…………………………75

iii.  Solubility Maps for Classes……………………………..76

iv.  Primary Causes for Heavy Oil Insolubility…………….80

e.  The Oil Compatibility Model……………………………………………81

A.  Colloidal-Solution Hybrid Model of Petroleum………………..81

B.  Modes of Asphaltene Fouling……………………………………82

C.  Flocculation Solubility Parameter……………………………….83

D.  Toluene-Heptane Scale…………………………………………...84

i.  Insolubility Number………………………………………84

ii.  Solubility Blending Number…………………………..…84

E.  Measurement of Compatibility Numbers……………………….85

F.  Prediction of Compatibility…………………………………...…86

G.  Oil Compatibility Tests…………………………………………..89

H.  Effect of Blending in Wrong Order…………………………..…90

I. Pairs of Incompatible Crude Oils………………………………..93

J.  Comparison with P-Test……………………………………….…94

K.  Self-Incompatible Crude Oils…………………………………....95

L.  Solution to Hydrotreater Plugging Problem……………………96

i.  Determining Compatibility Numbers on Oils Without Asphaltenes…………………………………………...….102

ii.  Range of Compatibility Numbers………………………105

iii.  Root Cause Analysis………………………...…………..106

M.  Effect of n-Paraffin Nonsolvent Carbon Number……………..107

i.  Similar Size Solvents and Nonsolvents………………...108

ii.  Effective Solubility Parameter………………………….109

N.  Synthetic Asphaltene Dispersants……………………………...112

f.  Limitations and Future Developments in Phase Behavior...... …115

4.  Separation of Heavy Oils……………………………………………...…….116

a.  Desalting……………………………...………………………………….121

A. Causes and Mitigation of Stable Oil-Water Emulsions……...124

b.  Distillation……………………………………………………...………..127

A.  Refinery Distillation……………………………………………..127

B.  Lab Distact Distillation……………………………………….....130

c.  Deasphalting…………………………………………………………...... 135

A.  Separation of Resins Fraction…………………………………..137

B.  General Resids………………………………………………...... 138

C.  Separability of Cold Lake Bitumen……………..……………...140

i.  CCR…………………...………………………………….144

ii.  Metals…………………...……………………………..…145

D.  Lab Separability of Arab Heavy Vacuum Resid…………...…147

i.  Cyclohexne-Attapulgus Clay of Resid…...…………….148

ii.  Cyclohexne-Attapulgus Clay of Visbroken Resid……..149

E.  Molecular Limitations to Separation…………………………..151

5.  Thermal Conversion Kinetics………………………………………………153

a.  Desirable Attributes for Kinetic Model………………………………..160

b.  Pseudocomponent Model ………………………………………...…….161

A.  Two Species Model for Fractions……………………………....162

B.  Reaction Limit…………………………………………………...162

C.  Phase Separation Step for Coke Formation…………………...162

D.  Series Reactions………………………………………………….163

E.  Stoichiometric Coefficients………………………..……………163

F.  First Order Reactions…………………………………………...165

G.  Effect of Initial Asphaltene Concentration…………………….167

H.  Effect of Reaction Temperature………………………………..170

I. Open versus Closed Reactors………………………………..…172

J.  Effect of Resid Type……………………………………………..173

K.  Relation of Rate Constants to Sulfur Type…………………….175

L.  Carbonaceous Mesophase………………………………………176

M.  Most Associated Asphaltenes Form Coke……………………..177

N.  Verification with Asphaltene Properties………………….……178

O.  Verification of Series Reactions………………………….……..180

P.  Hydrogen Balance Constraints on Coefficients……………….185

Q.  Simplified Kinetic Model…………………………………….....296

c.  Direct Measure of Kinetics with TGA………………………………....298

d.  Score Card on Desirable Attributes……………………………………201

Second Day

e.  Hydrogen Donors………………………………………………………..202

A.  Measurement of H-Donor Quantity and Relative Reactivity...203

B.  H-Donor Quantities and Relative Reactivities of Feeds………205

C.  Effect of Thermolysis on H-Donor Quantity…………………..206

D.  Generation of H-Donors by Saturates……………………...….208

E.  Effect of Reactive H-Donor on Thermolysis……………….…..209

f.  Implication of Thermal Kinetics on Heavy Oil Processing………..….210

g.  Future Developments in Thermal Conversion Kinetics………………211

6.  Resid Processing……………………………………………………………..212

a.  Upgrading Options……………………………………………………...227

b.  Selection of Resid Conversion Processes………………………………228

c.  Resid Fluid Catalytic Cracking………………………………………...229

A.  RFCC Feed Guidelines………………………………………….231

B.  Resid vs Gas Oil FCC…………………………………………...233

C.  FCC Reactions…………………………………………………..234

i. Cracking…………………………………………………235

ii. Disproportion……………………………………………236

iii Hydrogen Transfer……………………………………...237

D.  Comparison of Catalytic and Thermal Cracking……………..240

E.  Value of Riser Reactor…………………………………...……..241

F.  Yields of Gas Oil, Atm Resid, & HDS Am Resid……………...243

d.  Visbreaking……………………………………………………...………245

A.  Limitations……………………………………………………….248

i.  Asphaltene Sediments…………………………………...249

ii.  Coke Deposits………………………………………...….251

B. Ways to Increase Conversion…………………………………..252

i.  OCM Predicts Induction Period………………………..252

ii.  Remove Volatile Nonsolvent, Add Solvent Oil………...253

iii.  Hydrogen Donor Solvent Conversion………………….256

iv.  Coat Reactor Surface……………………………………257

v.  Couple Visbreaker and Deasphalter………………...…258

e.  Fixed Bed Hydrotreating….…………………………………………....259

A.  Heat Exchanger Fouling after Hydrotreater…………………..260

i.  Effect of Resins/Asphaltenes Ratio……………………..261

ii.  Effect of Metals Deposition on Catalyst………………..262

f.  Hydroconversion………………………………………………...………264

A.  Ebulated Bed…………………………………………………….265

i.  Deposits in Separators…………………………………..267

ii.  IFP Study of Sediments…………………………………268

B.  Dispersed Catalyst………………………………………………269

i. Formation of Catalyst………………………………….270

ii Microcat-RCProcess……………………….…….…….271

iii 90+ Conversion May Not be Optimum……………….273

iv. Learnings from Microcat Compatibility……………..274

v. Eni Slurry Technology…………………………………275

g.  Coking……………………………………………………………………278

A.  Delayed Coking………………………………………………….280

B.  Fluid Coking……………………………………………………..285

C.  Flexicoking……………………………………………………….289

D.  Optimum Coking………………………………………………..293

i.  Undesirable Reactions…………………………………..294

ii.  Reduction of Secondary Cracking of Products………..295

iii.  Ideal Coking Potential: Yield vs. Quality……………...296

iv.  Reduction of Feed Degradation………………………...299

h.  Resid Conversion Can Be Improved………………………………,,,…306

i.  Choosing Resid Process for a Refinery……………………………...…307

j.  Heavy Oil Processing in the Future…………………………………….311

7.  Mitigation of Fouling………………………………………………………..312

a.  What is fouling?...... 322

b.  Fouling Analytical Strategy ……………………...…………………….323

c.  Diagnosis & Investigation of Fouling………………………………...... 324

A.  Most Common Causes…………………………………………..325

B.  Process Conditions/History……………………………………..326

C.  Analysis of Foulant…………………………………………...…327

D.  Analysis of Oil………………………………………………...…330

E.  Evidence of Most Common Causes…………………………….331

d.  Innovation & Mitigation………………………………………………..332

A.  Causes of Fouling Suggest Solutions…………………………...333

e.  Case Study: Coker Fractionator Fouling…………………………...…336

A.  Polymerization of Conjugated Olefins………………………...338

B.  Measurement of Diene Value…………………………………..339

C.  Mitigation………………………………………………………..340

f.  Engineering Methods of Fouling Mitigation…………………………..342

g.  Future Developments in Fouling Mitigation…………………………..344