PROCESS FOR PRODUCTION OF TEREPHTHALIC ACID

摘要

THE INVENTION PROVIDES A METHOD FOR PRODUCING TEREPHTHALIC ACID, CHARACTERIZED BY INCLUDING SUBJECTING A P-PHENYLENE COMPOUND TO LIQUID-PHASE OXIDATION REACTION BY USE OF A MOLECULAR-OXYGEN-CONTAINING GAS IN THE PRESENCE OF A CATALYST AT LEAST CONTAINING A HEAVY METAL COMPOUND AND A BROMINE COMPOUND, AND HYDROUS ACETIC ACID HAVING A WATER CONTENT OF 1 TO 15 MASS%, TO THEREBY YIELD A SLURRY; REGULATING THE TEMPERATURE OF THE SLURRY TO 35 TO 140°C, TOTHEREBY CAUSE TEREPHTHALIC ACID TO PRECIPITATE; REMOVING THE TEREPHTHALIC ACID THROUGH SOLID-LIQUID SEPARATION, TO THEREBY RECOVER A MOTHER LIQUOR; AND RECOVERING THE CATALYST FROM THE MOTHER LIQUOR THROUGH A SERIES OF THE FOLLOWING STEPS (1) TO (4) FOR REUSING AT LEAST A PORTION OF THE CATALYST IN THE LIQUID-PHASE OXIDATION REACTION: (1) AN ADSORPTION STEP INCLUDING REGULATING THE RATIO "AMOUNT BY MOLE OF BROMIDE IONS IN THE MOTHER LIQUOR/TOTAL AMOUNT BY MOLE OF HEAVY METAL IONS IN THE MOTHER LIQUOR" TO 0.6 TO 3, AND THEN EXPOSING THE MOTHER LIQUOR TO A PYRIDINE-RING-CONTAINING CHELATE RESIN WHICH HAS BEEN HEATED TO 35 TO 140°C, SO THAT THE RESIN ADSORBS CATALYST-DERIVED HEAVY METAL IONS AND BROMIDE IONS, AND ALSO ADSORBS A CARBOXYLIC ACID MIXTURE WHICH HAS BEEN BY- PRODUCED THROUGH THE LIQUID-PHASE OXIDATION REACTION, (2) AN ELUTION STEP (A) OF EXPOSING HYDROUS ACETIC ACID HAVING A WATER CONTENT OF 1 TO 15 MASS% TO THE PYRIDINE-RING- CONTAINING CHELATE RESIN WHICH HAS UNDERGONE THE ADSORPTION STEP, THEREBY YIELDING AN ELUATE CONTAINING THE BY-PRODUCE CARBOXYLIC ACID MIXTURE, (3) AN ELUATION STEP (B) OF EXPOSING WATER HYDROUS ACETIC ACID HAVING A WATER CONTENT OF 20 MASS% OR MORE TO THE PYRIDINE-RING-CONTAINING CHELATE RESIN WHICH HAS UNDERGONE THE EVALUATION STEP (A), THEREBY YIELDING AN ELUATE IONS, AND (4) A DISPLACEMENT STEP OF EXPOSING HYDROUS ACETIC ACID HAVING A WATER CONTENT RESIN WHICH HAS UNDERGONE THE ELUATION STEP (B), SERVING AS A DISPLACEMENT LIQUID, THEREBY REGENERATING THE RESIN.