STAGE COUNTER-CURRENT OXIDATION

PROBLEM TO BE SOLVED: To provide an oxidation method that is capable of increasing rated capacity of a commercial oxidation system without necessitating the further addition of compressor capacity by maximizing the utilization of oxygen to thereby improve the process efficiency while highly maintaining the quality of a carbonic acid product to be manufactured. SOLUTION: The oxidation method comprises introducing to a first oxidation stage a supply mixture containing at least one part of each a predetermined total amount of (i) a solvent, (ii) a catalyst ingredient containing at least one of catalyst metals and (iii) bromine, and about 7-about 60 wt.% of a predetermined total amount of at least one of a disubstituted benzene to be introduced, thereby partially oxidizing the disubstituted benzene to obtain a first product mixture, introducing to a second oxidation stage the first product mixture, a molecular oxygen and the residual amount of (i)-(iii), thereby completely oxidizing the unreacted disubstituted benzene to recover a second product mixture containing an acid derivative product and returning the remaining molecular oxygen to the first oxidized stage. COPYRIGHT: (C)2005,JPO&NCIPI