METHOD OF PRODUCING AROMATIC CARBOXYLIC ACID

摘要

PROBLEM TO BE SOLVED: To provide a method of producing an aromatic carboxylic acid by liquid phase oxidation of an aromatic alkylhydrocarbon, in which the loss of the reaction medium due to its combustion is significantly lowered and the aromatic aldehyde content of the crude aromatic carboxylic acid crystal can be freely regulated. SOLUTION: In method of producing an aromatic carboxylic acid by liquid phase oxidation of an aromatic alkylhydrocarbon with a molecular oxygen- containing gas in a liquid reaction medium in the presence of a catalyst containing cobalt, manganese and bromine the reaction medium-aromatic carboxylic acid slurry formed in a 1st oxidation reactor with the oxidation temperature set to be 140-180 deg.C is subjected to the 2nd oxidation treatment in a 2nd oxidation reactor with its temperature kept at a temp of 140-190 deg.C, without feeding the aromatic alkylhydrocarbon any more, for such a retention time as to be determined by a specific formula based on the aromatic aldehyde content of the aromatic carboxylic acid crystal in the 1st oxidation reactor.