Process and apparatus for producing aromatic carboxylic acid.

摘要

It is contemplated by the present invention to produce a high quality aromatic carboxylic acid by a liquid phase oxidation of an alkylbenzene by contacting it with a molecular oxygen-containing gas in a solvent containing a lower aliphatic carboxylic acid, under exclusion of any acceleration of decomposition of the solvent molecules and danger of explosion accident. The process for producing an aromatic carboxylic acid according to the present invention by a liquid phase oxidation of an alkylbenzene by contacting the alkylbenzene with a molecular oxygen-containing gas in a solvent containing a lower aliphatic carboxylic acid comprises supplying the alkylbenzene and the solvent to a reactor, supplying, as the molecular oxygen-containing gas, a high oxygen content gas containing molecular oxygen at a concentration higher than that of air to the reactor, circulating at least a part of the reactor exhaust gas as such or after having been separated from the condensable components thereof to the liquid layer in the reactor and thereby oxidizing the alkylbenzene to the aromatic carboxylic acid.