Report No. 9-A TEREPHTHALICACID AND DIMETHYLTEREPHTHALATE SUPPLEMENT A by LLOYD M. ELKIN m . contributions by SHIGEYOSHI TAKAOKA January 1967 A private report by the l PROCESS ECONOMICS PROGRAM STANFORD RESEARCH INSTITUTE MENLO PARK, CALIFORNIA I CONTENTS I INTRODUCTION. ........................ 1 II SUMMARY ........................... 3 III INDUSTRY STATUS . 9 IV CHEMISTRY . 15 Ammoxidation of p-Xylene . 15 Terephthalic Acid by Bromine-Promoted Catalytic Air Oxidation ofp-Xylene......................... 17 Terephthalic Acid by Catalytic Oxidation of p-Xylene in the Presence of Methyl Ethyl Ketone (MEK) Activator , . 18 Terephthalic Acid by Nitric Acid Oxidation of p-Xylene . 19 Terephthalic Acid from Phthalic Anhydride . 19 Dimethyl Terephthalate from p-Xylene by Successive Oxidations and Esterifications . 20 V BIS(B-HYDROXYETHYL) TEREPHTHALATE FROM TEREPHTHALONITRILE MADE BY AMMOXIDATION OF P-XYLENE ................. 23 Review of Processes ..................... 23 Crude Terephthalonitrile Production and Purification .... 23 Ammonia Recovery ...................... 27 Bis(2-hydroxyethyl) terephthalate Production and Purification ....................... 27 Process Description ..................... 29 Process Discussion ..... ; ................ 51 Crude Terephthalonitrile Production ............ 51 Ammonia Recovery ...................... 52 Terephthalonitrile Purification .............. 52 Bis(2-hydroxyethyl) terephthalate Production ........ 52 Bis(2-hydroxyethyl) terephthalate Purification ....... 53 Ethylene Glycol Recovery .................. 54 Capital Cost ......................... 54 Production Cost ....................... 54 Analysis of Effects of Process Changes on Costs ....... 61 Other Processes for Producing Terephthalonitrile ....... 67 Ammoxidation of Divinyl Benzene .............. 67 Reaction of Benzene with Cyanogen ............. 68 Reaction of p-Xylene with NO ................ 68 Reaction of p-Xylene, Sulfur, and Ammonia ......... 69 iii CONTENTS V (continued) Liquid Phase Ammoxidation ................. 70 Reaction of Benzonitrile with HCN ............. 71 Intermolecular Rearrangement of Benzonitrile ........ 72 0 Reaction of N-alkyl Substituted Aromatic Amines with NO . 72 Miscellaneous Patents Concerning Terephthalonitrile .... 73 VI GENERAL REVIEW OF PROCESSES AND DISCUSSION OF POSSIBLE CHANGES IN THE DESIGNS PRESENTED IN THE ORIGINAL REPORT ....... 75 Purification of Terephthalic Acid and Dimethyl Terephthalate . 75 Changes in Original Design .................. 81 Terephthalic Acid by Bromine-Promoted Catalytic Air Oxidation ofp-Xylene ......................... 82 Changes in Original Design .................. 82 Terephthalic Acid by Catalytic Oxidation of p-Xylene in the Presence of Methyl Ethyl Ketone (MEK) Activator ....... 82 Changes in Original Design .................. 83 0 Terephthalic Acid from Phthalic Anhydride .......... 87 Changes in Original Design .................. 88 Terephthalic Acid by Nitric Acid Oxidation of p-Xylene .... 92 Changes in Original Design .................. 92 Dimethyl Terephthalate by Esterification of Terephthalic Acid ............................ 92 Changes in Original Design .................. 93 Dimethyl Terephthalate by Successive Oxidations and Esterifications ....................... 94 Changes in Original Design .................. 94 APPENDIX A DESIGN AND COST BASIS ................. 97 APPENDIX B PHYSICALDATA ..................... 103 a APPENDIX C HANDLINGANDSAFETY .................. 107 CITEDREFERENCES .......................... 113 0 SUPPLEMENTARYREFERENCES. ..................... 121 ERRATATOPEPREPORTNO.9 ..................... 129 iv ILLUSTRATIONS 1 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by the Ammoxidation of p-Xylene ............. 33 2 Alternate Route, MEX Activator Process ............ 85 3 Modified Route to TPA via Phthalic Anhydride ......... 89 4 Terephthalonitrile, Vapor Pressure versus $ ......... 106 V TABLES 1 Summary of Process Evaluated (Base Case Design) . 5 2 Plant Capacities--Japan . 11 3 Production of Terephthalonitrile by Ammoxidation of p-Xylene Review of Processes . 25 4 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by the Ammoxidation of p-Xylene Major Process Equipment List . 30 5 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by the Ammoxidation of p-Xylene Stream Flows . 39 6 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by Ammoxidation of p-Xylene Utilities Summary . 45 7 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by Ammoxidation of p-Xylene Process Unit and Utilities Investment . 55 8 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by the Ammoxidation of p-Xylene Total Capital Investment . 57 9 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by Ammoxidation of p-Xylene Production Costs . 59 10 Bis(2-hydroxyethyl) terephthalate from Terephthalonitrile Made by Ammoxidation of p-,Xylene Effects of Process Changes on Cost . 63 11 Purification of Terephthalic Acid and Dimethyl Terephthalate Review of Processes . 77 vii .