METHOD FOR MANUFACTURING TEREPHTHALIC ACID

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing terephthalic acid which method completes the reaction of an intermediate in a mother liquor without increasing the combustion loss of acetic acid while decreasing the amount of colored substances and thereby gives terephthalic acid of high qualities. SOLUTION: The method for manufacturing terephthalic acid by oxidizing p-xylene with molecular oxygen in the presence of a catalyst in an acetic acid solvent comprises a step A for oxidizing at least 95 wt% of p-xylene at 180-240°C in the first oxidation reaction zone equipped with a complete mixing tank-type reactor and a step B for additionally oxidizing p-xylene in a temperature range from a temperature 10°C lower to that 10°C higher than the temperature in the step A in the second oxidation reaction zone equipped with a piston flow-type reactor. COPYRIGHT: (C)2004,JPO