Abstract Process Economics Program Report 7C CAPROLACTAM (May 1998)
This supplementary report presents an overview of the technical and economic aspects of modern caprolactam manufacture and identifies specific process improvements developed since PEP Report 41B, Nylon 6 and Caprolactam , was issued in March 1988. Because the vast majority of today’s caprolactam is produced from cyclohexanone, we pri- marily focus on the cyclohexanone based routes in our review of recent technology improvements in caprolactam manufacturing technology. In particular, we highlight the environmental aspects of caprolactam production, especially for cyclohexane oxidation and hydroxylamine production technologies. Two process technologies are evaluated in detail: • DSM’s hydroperoxide process—a commercial cyclohexane oxidation process for cyclo- hexanone manufacture • EniChem’s ammoximation process—a newly commercialized oximation process for cy- clohexanone oxime manufacture Comparison economics are presented for major commercial and developing technologies for the production of cyclohexanone, cyclohexanone oxime, and caprolactam. For producers of caprolactam and its intermediates, this report will be useful for the compar- ative economics it provides, as well as for its extensive review of recently issued patents and published literature.
PEP’95 7C AEH CONTENTS
GLOSSARY...... xv
1 INTRODUCTION...... 1-1
2 SUMMARY ...... 2-1
TECHNICAL ASPECTS ...... 2-1
Cyclohexanone Production ...... 2-1
Cyclohexanone Oxime Production...... 2-2
Caprolactam Production...... 2-7
ECONOMIC ASPECTS...... 2-11
Cyclohexanone Production ...... 2-11 Investment Capital...... 2-11 Production Costs...... 2-13
Cyclohexanone Oxime Production...... 2-15 Investment Capital...... 2-15 Production Costs...... 2-15
Caprolactam Production...... 2-17 Investment Capital...... 2-21 Production Costs...... 2-21 Profitability...... 2-25
3 INDUSTRY STATUS...... 3-1
GLOBAL CAPACITY OVERVIEW...... 3-1
SUPPLY AND DEMAND ...... 3-4
North America ...... 3-5
Western Europe ...... 3-10
Japan...... 3-12
4 TECHNOLOGIES FOR MANUFACTURING CYCLOHEXANONE...... 4-1
CYCLOHEXANONE VIA CYCLOHEXANE OXIDATION ...... 4-5
Cyclohexane Oxidation—Chemistry...... 4-5
Cyclohexane Oxidation—Process Design ...... 4-6
i CONTENTS (Continued)
4 TECHNOLOGIES FOR MANUFACTURING CYCLOHEXANONE (Concluded) Cyclohexanone Recovery ...... 4-24 Environmental Issues...... 4-25
CYCLOHEXANONE FROM CYCLOHEXENE...... 4-26
Cyclohexene Hydration ...... 4-26
Cyclohexene Epoxidation...... 4-26
Cyclohexene Oxidation ...... 4-26
5 CYCLOHEXANONE FROM CYCLOHEXANE VIA THE HYDROPEROXIDE ROUTE...... 5-1
PROCESS DESCRIPTION ...... 5-2
Section 100—Cyclohexane Oxidation...... 5-2
Section 200—Cyclohexanone Production...... 5-3
Section 300—Cyclohexane Recovery...... 5-3
PROCESS DISCUSSION ...... 5-16
Oxidation ...... 5-16
Decomposition...... 5-17
Cyclohexane Recycle...... 5-17
By-products ...... 5-17
Wastewater ...... 5-18
Safety ...... 5-18
COST ESTIMATES ...... 5-18
Capital Investment Costs ...... 5-18
Production Costs ...... 5-19
6 TECHNOLOGIES FOR MANUFACTURING CYCLOHEXANONE OXIME ...... 6-1
HYDROXYLAMINE PRODUCTION...... 6-3
HAS Production...... 6-3 Commercial Raschig Processes ...... 6-5 “Direct” Raschig Processes...... 6-6
iii CONTENTS (Continued)
6 TECHNOLOGIES FOR MANUFACTURING CYCLOHEXANONE OXIME (Concluded) Nitric Oxide Reduction Process ...... 6-8
HAAS Production ...... 6-10
HAP Production...... 6-10
Hydroxylamine Production from Ammonia ...... 6-10
Environmental Issues ...... 6-11 Wastewater ...... 6-11 Nitrogen Oxides...... 6-11
CYCLOHEXANONE OXIMATION...... 6-14
Oximation by HAS—The Conventional Process ...... 6-15
Oximation by HAAS—the HSO Process ...... 6-16
Oximation by HAP—the HPO Process...... 6-18
Direct Oximation by Hydroxylamine ...... 6-20
Direct Ammoximation Processes—Liquid Phase ...... 6-20
Direct Ammoximation Processes—Vapor Phase...... 6-21
Other Cyclohexanone Oximation Processes ...... 6-22
Environmental Issues ...... 6-23
CYCLOHEXYLAMINE OXIDATION ...... 6-23
7 CYCLOHEXANONE OXIME FROM CYCLOHEXANONE VIA AMMOXIMATION ...... 7-1
PROCESS DESCRIPTION ...... 7-1
Section 100—Cyclohexanone Ammoximation ...... 7-3
Section 200—Oxime Recovery ...... 7-3
PROCESS DISCUSSION ...... 7-10
Reaction Steps ...... 7-10
Reaction Selectivity ...... 7-10
Reaction Solvent ...... 7-11
Reactor Design...... 7-11
Catalyst ...... 7-13
iv CONTENTS (Continued)
7 CYCLOHEXANONE OXIME FROM CYCLOHEXANONE VIA AMMOXIMATION (Concluded)
Solvent Extraction ...... 7-17
Vacuum System ...... 7-17
Waste Streams...... 7-17
COST ESTIMATES ...... 7-18
Investment Costs...... 7-18
Production Costs ...... 7-22
8 TECHNOLOGIES FOR MANUFACTURING CAPROLACTAM ...... 8-1
OXIME REARRANGEMENT...... 8-3
Conventional Liquid Phase Rearrangement...... 8-3
Other Liquid Phase Rearrangement Processes...... 8-5
Modified Neutralization Processes ...... 8-5
Solid Acid Catalysts...... 8-6
Vapor Phase Rearrangement...... 8-6 Feed Diluents ...... 8-8 Catalysts...... 8-8
Environmental Issues ...... 8-10
CAPROLACTAM PURIFICATION AND RECOVERY...... 8-11
Purification of Caprolactam from Liquid Phase Rearrangement ...... 8-12
Purification of Caprolactam from Vapor Phase Rearrangement ...... 8-14
Caprolactam Hydrogenation...... 8-14
Anhydrous Caprolactam...... 8-15
Purification of Lactam Mixtures ...... 8-15
Caprolactam Recovery from Waste Streams...... 8-16
Environmental Issues ...... 8-16 Extraction Waste Streams...... 8-16 Distillation Waste Streams ...... 8-17 Crystallization Waste Streams ...... 8-17
v CONTENTS (Concluded)
8 TECHNOLOGIES FOR MANUFACTURING CAPROLACTAM (Concluded)
AMMONIUM SULFATE RECOVERY...... 8-18
Ammonium Sulfate Recovery and Purification ...... 8-18
Environmental Issues ...... 8-18
APPENDIX A: PATENT SUMMARY TABLES...... A-1
APPENDIX B: DESIGN AND COST BASES...... B-1
APPENDIX C: CITED REFERENCES...... C-1
APPENDIX D: PATENT REFERENCES BY COMPANY...... D-1
APPENDIX E: PROCESS FLOW DIAGRAMS ...... E-1
vi ILLUSTRATIONS
1.1 Commercial Routes to Caprolactam Production ...... 1-2
2.1 Commercial Routs to Caprolactam Production—Figure Guide...... 2-3
2.2 Cyclohexanone Synthesis Routes ...... 2-4
2.3 Hydroxylamine Synthesis Routes ...... 2-5
2.4 Cyclohexanone Oxime Synthesis/Rearrangement Routes ...... 2-6
2.5 PNC and CHCA Caprolactam Production Routes ...... 2-8
2.6 By-Product Ammonium Sulfate Production...... 2-9
2.7 Butadiene-Based Caprolactam Production Routes...... 2-10
2.8 Breakdown of Net Production Cost for Selected Cyclohexanone Technologies ...... 2-14
2.9 Breakdown of Net Production Cost for Selected Oximation Technologies...... 2-8 2.10 Breakdown of Net Production Cost for Selected Caprolactam Technologies...... 2-22
2.11 Breakdown of Net Production Cost for Selected Caprolactam Technologies: 10-Year Feedstock Price average ...... 2-24
2.12 ROI before Taxes for Selected Caprolactam Technologies...... 2-25
4.1 Scope for Technology Review ...... 4-2
4.2 Available Routes to Cyclohexanone Production ...... 4-3
4.3 Cyclohexanone Synthesis Routes ...... 4-4
4.4 Cyclohexanone via Cyclohexane Oxidation Flow Diagram for the Conventional Process...... 4-8
4.5 Cyclohexanone via Cyclohexane Oxidation Flow Diagram for the IFP Boric Acid Process ...... 4-11
4.6 Cyclohexanone via Phenol Hydrogenation Flow Diagram for Liquid Phase Hydrogenation...... 4-22
4.7 Cyclohexanone via Phenol Hydrogenation Flow Diagram for Vapor Phase Hydrogenation...... 4-23
5.1 Cyclohexanone via Cyclohexane Oxidation by the Hydroperoxide Process ...... E-3
5.2 Cyclohexanone via Cyclohexane Oxidation Effect of Decomposition Catalyst Life on Product Value...... 5-26
6.1 Scope for Technology Review ...... 6-2
vii ILLUSTRATIONS (Concluded)
6.2 Hydroxylamine Production Major Synthesis Routes to Hydroxylamine ...... 6-4
6.3 Hydroxylamine Production Flow Diagram for Montedipe’s “Direct” Raschig Process...... 6-7
6.4 Cyclohexanone Oxidation Flow Diagram for BASF’s HSO Process ...... 6-17
6.5 Cyclohexanone Oxidation Flow Diagram for DSM’s HPO Process ...... 6-19
7.1 Cyclohexanone Oxime from Cyclohexanone via Ammoximation...... E-5
7.2 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Effect of Reaction Solvent on Conversion and Selectivity ...... 7-12
7.3 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Effect of Catalyst Type on Conversion and Selectivity...... 7-14
7.4 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Effect of Catalyst Ti Content on Conversion and Selectivity ...... 7-15
7.5 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Effect of Catalyst Concentration on Conversion and Selectivity ...... 7-16
7.6 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Effect of Hydrogen Peroxide Cost on Oxime Product Value...... 7-28
8.1 Scope for Technology Review ...... 8-2
8.2 Oxime Rearrangement Flow Diagram for the BASF Vapor Phase Process...... 8-7
8.3 Caprolactam Recovery And Purification Flow Diagram for the Stamicarbon-Based Purification Process ...... 8-13
8.4 Ammonium Sulfate Recovery And Purification Flow Diagram for the Stamicarbon-Based Process ...... 8-19
viii TABLES
1.1 Comparison of Cyclohexanone Production Routes ...... 1-2
2.1 Comparison of Cyclohexanone Production Routes ...... 2-12
2.2 Comparison of Cyclohexanone Oxime Production Routes ...... 2-16
2.3 Comparison of Investments For Caprolactam Production Routes ...... 2-19
2.4 Comparison of Caprolactam Production Routes...... 2-20
2.5 Variable Cost Comparison of Caprolactam Production Routes ...... 2-23
3.1 World Capacity, 1997 and 2001...... 3-1
3.2 Capacity Share by Raw Material, 1997...... 3-2
3.3 Five Largest Caprolactam Producers: Capacity as of January 1, 1997...... 3-3
3.4 World Supply/Demand for Caprolactam, 1996 ...... 3-4
3.5 World Production and Consumption of Nylon 6 Fibers, 1996 ...... 3-5
3.6 Global Capacity for Nylon 6 Fibers ...... 3-5
3.7 North American Caprolactam Producers ...... 3-7
3.8 North American Caprolactam Statistics, 1995 and 1996 ...... 3-8
3.9 North American Caprolactam Producer/ Consumer Integration as of January 1, 1997...... 3-9
3.10 Western European Caprolactam Producers ...... 3-10
3.11 Western European Caprolactam Statistics, 1995 and 1996 ...... 3-11
3.12 Japan Caprolactam Producers...... 3-12
3.13 Japanese Caprolactam Statistics, 1995 and 1996 ...... 3-13
4.1 Cyclohexane Oxidation Patent Summary...... A-3
4.2 Cyclohexyl Hydroperoxide (CHHP) Conversion Patent Summary...... A-12
4.3 Cyclohexanol Conversion and Cyclohexanone Recovery Patent Summary...... A-21
4.4 Waste Treatment and By-Product Recovery Patent Summary...... A-25
4.5 Raw Material and Utility Requirements for a Cyclohexane Oxidation Unit (Boric Acid Process) ...... 4-12
4.6 Sample Heavy Ends Composition for Cyclohexanone via Cyclohexane Oxidation ...... 4-18
ix TABLES (Continued)
4.7 Phenol Hydrogenation Patent Summary...... A-28
4.8 Raw Material and Utility Requirements for a Vapor Phase Phenol Hydrogenation Unit...... 4-24
4.9 Cyclohexanone from Cyclohexene Patent Summary...... A-31
5.1 Cyclohexanone via Cyclohexane Oxidation by the Hydroperoxide Process Design Bases and Assumptions ...... 5-4
5.2 Cyclohexanone via Cyclohexane Oxidation Stream Flows ...... 5-7
5.3 Cyclohexanone via Cyclohexane Oxidation Major Equipment ...... 5-12
5.4 Cyclohexanone via Cyclohexane Oxidation Utilities Summary ...... 5-15
5.5 Cyclohexanone via Cyclohexane Oxidation Total Capital Investment...... 5-20
5.6 Cyclohexanone via Cyclohexane Oxidation Capital Investment by Section...... 5-21
5.7 Cyclohexanone via Cyclohexane Oxidation Production Costs...... 5-22
5.8 Cyclohexanone via Cyclohexane Oxidation Direct Costs by Section...... 5-24
5.9 Cyclohexanone via Cyclohexane Oxidation Raw Material Cost Comparison...... 5-25
6.1 Hydroxylamine Production Patent Summary...... A-34
6.2 Cyclohexanone Oximation Patent Summary...... A-40
7.1 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Design Bases and Assumptions ...... 7-2
7.2 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Stream Flows ...... 7-5
7.3 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Major Equipment ...... 7-7
7.4 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Utilities Summary ...... 7-9
x TABLES (Concluded)
7.5 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Total Capital Investment...... 7-19
7.6 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Capital Investment by Section...... 7-20
7.7 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Economic Comparison with Established Technologies...... 7-21
7.8 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Production Costs ...... 7-23
7.9 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Direct Costs by Section...... 7-25
7.10 Cyclohexanone Oxime from Cyclohexanone via Ammoximation Raw Material Cost Comparison...... 7-27
8.1 Oxime Rearrangement Patent Summary...... A-47
8.2 Oxime Rearrangement Development of Vapor Phase Processes ...... 8-9
8.3 Caprolactam Purification and Recovery Patent Summary...... A-54
8.4 Ammonium Sulfate Recovery Patent Summary...... A-63
xi