Report No. 9C Supplement TEREPHTHALIC ACID AND DIMETHYL TEREPHTHALATE by LLOYD M. ELKIN and FUMIHIKO YAMAGUCHI August 1976 A private report by the PROCESS ECONOMICS PROGRAM STANFORD RESEARCH INSTITUTE MENLO PARK, CALIFORNIA I For detailed marketing data and information, the reader is referred to one of the SRI programs specializing in marketing research. The CHEMICAL ECONOMICS HANDBOOK Program covers most major chemicals and chemical products produced in the United States and the WORLD HYDROCARBONS Program covers major hydrocarbons and their derivatives on a worldwide basis. In addition, the SRI DIRECTORY OF CHEMICAL PRODUCERS services provide detailed lists of chemical producers by company, product, and plant for the United States and Western Europe. ii CONTENTS 1 INTRODUCTION . 1 2 SUMMARY . 3 Industry Status ....................... 3 Description of Processes Evaluated .............. 4 Capital and Production Costs ................. 7 Future Developments ..................... 10 3 INDUSTRYSTATUS . 11 4 CHEMISTRY . 17 TPA from p-Xylene by Bromine-Promoted Catalytic Air Oxidation . 17 DMT from p-Xylene by Successive Oxidations and Esterifications. 19 Ammoxidation of p-Xylene . l . 20 TPA from Phthalic Anhydride (or Benzoic Acid) . 21 TPA from p-Xylene by Catalytic Oxidation in the presence of Activators . 22 TPA from p-Xylene by Liquid Phase Oxidation in the Presence of Large Amounts of Catalyst . 22 5 REVIEW OF PATENTS . 25 TPA from p-Xylene by Bromine-Promoted Catalytic Air Oxidation , 25 TPA from p-Xylene by Catalytic Oxidation in the Presence of Activators ........................ 3l. TPA from Phthalic Anhydride or Benzoic Acid ......... 31 TPA from p-Xylene by Nitric Acid Oxidation ......... 40 TPA Purification ...................... 40 DMT from Crude TPA by Esterification with Methanol ..... 51 DMT Purification ....................... 55 Stabilizers for Molten DMT ................. 55 Catalyst.Recovery .................. 55 Other Oxidation Processes ................. l 55 6 TEREPHTHALIC ACID FROM p-XYLENE BY BROMINE-PROMOTED CATALYTIC AIR OXIDATION, CONVENTIONAL PROCESS ............. 63 Updated Capital Costs .................... 63 Updated Production Costs ................... 63 Discussion of Factors Affecting Costs ............ 63 Vii CONTENTS 7 DIMETHYL TEREPHTHALATE FROM p-XYLENE BY SUCCESSIVE OXIDATIONS AND ESTERIFICATIONS ..................... 69 Review of Patents ....................... 69 Oxidation Step ....................... 69 Esterification Step ..................... 73 Purification of DMT ..................... 73 Treatment of Distillation Residues ............. 74 Recovery of Oxidation Catalyst ............... 74 Process Description ...................... 75 Process Discussion ...................... 87 Material Balance ................... 87 Oxidation Reactor Design .................. 87 Oxygen Consumption ................. 88 Esterification Reaction Time ................ 88 Heat of Esterification ................... 88 Methanol Distillation .................... 88 DMT Distillation Columns .................. 89 Column Design ........................ 89 Air Cooled Heat Exchangers ................. 89 Two-Stage Crystallization .................. 90 Balance on Generated and Consumed Low Pressure Steam .... 90 Stabilizers for Molten DMT ................. 90 Utility Consumptions .................... 91 Cost Estimates ................ ....... 91 Capital Costs ........................ 91 Production Costs ...................... 93 8 TEREPHTHALIC ACID FROM p-XYLENE; COPRODUCTION WITH DIMETHYL TEREPHTHALATE ........................ 97 Introduction 97 Process Description .............. .............................. 98 Process Discussion. ...................... 102 Material Balance 102 Reactions and Physical Changes Occuring in the Heat Treatment Vessels 102 Purification Method ..........................................103 Cost Estimates ........................ 103 Capital Costs ........................ 103 Production Costs ...................... 103 Cost Comparison ....................... 103 Viii CONTENTS 9 DIMETHYL TEREPHTHALATE FROM CRUDE TEREPHTHALIC ACID BY ESTERIFICATION WITH METHANOL . 111 Updated Capital Costs ..................... 111 Updated Production Costs .................... 111 Discussion of Factors Affecting Costs ............. 111 10 TEREPHTHALIC ACID FROM p-XYLENE BY BROMINE-PROMOTED CATALYTIC AIR OXIDATION, MODIFIED PROCESS .................. 119 Process Description .......... 119 Process Discussion, Purification Section,Batch versus 127 Continuous Operation ...................... 127 Process Discussion, Catalyst Recovery Section ......... 127 Batch versus Continuous Operation 127 Chemical Treatment Reactor R-301 . ,: ..........................127 Water Type.. ........................ 127 Carbon Dioxide Contamination ................. 128 Cost Estimates ......................... 128 Capital Costs 128 Production Costs' ..............................................128 11 TEREPHTHALIC ACID FROM p-XYLENE BY AMMOXIDATION AND HYDROLYSIS . 133 Review of Patents ....................... 133 Process Description ...................... 140 Process Discussion ....................... 161 By-Products in Ammoxidation of p-Xylene ........... 161 Overall Yield ........................ 162 Utilities Comparison ..................... 162 Materials of Construction .................. 162 Cost Estimates ......................... 163 Capital Costs 163 Production Costs' ..............................................163 CITED REFERENCES . 169 PATENT REFERENCES BY COMPANY . 187 ix ILLUSTRATIONS 6.1 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation, Conventional Process Effect of Operating Level and Plant Capacity on Production Costs l . l l . 66 7.1 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Flow Sheet . , 195 7.2 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Effect of Operating Level and Plant Capacity on Production Cost . , . 96 8.1 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate Flow Sheet . W . 199 8.2 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate Effect of Operating Level and Plant Capacity on Production Cost l l n . 109 9.1 Dimethyl Terephthalate from Crude Terephthalic Acid by Esterification with Methanol Effect of Operating Level and Plant Capacity on Production Cost . l . 117 10.1 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation, Modified Process Flow Sheet . ...201 10.2 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation, Modified Process Effect of Operating Level and Plant Capacity on Production Cost . l l . 132 11.1 Terephthalic Acid from p-Xylene by Ammoxidation and Hydrolysis Flow Sheet . ...203 11.2 Terephthalic Acid from p-Xylene by Ammoxidation and Hydrolysis Effect of Operating Level and Plant Capacity on Production Cost . 168 Xi TABLES 2.1 Summary of Capital and Production Costs . 8 3.1 Dimethyl Terephthalate and Terephthalic Acid Plant Capacities in the Americas . 13 3.2 Dimethyl Terephthalate and Terephthalic Acid Plant Capacities in Western Europe l l l l l l l . l l l l l 14 3.3 Dimethyl Terephthalate and Terephthalic Acid Plant Capacities in the Eastern Bloc Countries . 15 3.4 Dimethyl Terephthalate and Terephthalic Acid Plant Capacities in the Middle and Far East . 16 5.1 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation Patent Summary . 26 5.2 Terephthalic Acid from p-Xylene by Catalytic Oxidation in the Presence of Activators Patent Summary . 32 5.3 Terephthalic Acid from Phthalic Anhydride or Benzoic Acid Patent Summary . 36 5.4 Terephthalic Acid from p-Xylene by Nitric Acid Oxidation Patent Summary . 41 5.5 Terephthalic Acid Purification Patent Summary . 42 5.6 Dimethyl Terephthalate from Crude Terephthalic Acid by Esterification with Methanol Patent Summary . 52 5.7 Dimethyl Terephthalate Purification Patent Summary . 56 5.8 Stabilizers for Molten Dimethyl Terephthalate Patent Summary . •~~~o.....~~~~. 58 5.9 Catalyst Recovery Patent Summary . 59 5.10 Other Oxidation Processes Patent Summary . 62 xiii TABLES 6.1 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation, Conventional Process Total Capital Investment . 64 6.2 Terephthalic Acid from p-Xylene by Bromine-Promoted Catalytic Air Oxidation, Conventional Process Production Costs . 65 7.1 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Patent Summary: Oxidation Reaction . 70 7.2 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Major Equipment and Utilities Summary . 81 7.3 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Stream Flows . 84 7.4 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Sumnary of Reactor Conditions . 86 7.5 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Total Capital Investment . 92 7.6 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications Production Costs . 94 8.1 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate Major Equipment and Utilities Summary . 100 8.2 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate Stream Flows . .,. 101 8.3 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate Total Capital Investment . 106 xiv TABLES 8.4 Terephthalic Acid from p-Xylene; Coproduction with Dimethyl Terephthalate