PROSES DAN PERALATAN UNTUK MEMPRODUKSI ASAM KARBOKSILAT AROMATIK

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an aromatic carboxylic acid by which the reflux of a fraction containing a solvent at a low concentration and a low temperature from a distillation column to an oxidation reactional column can be prevented to facilitate the restart of an apparatus in the case of emergency stop, etc., of the apparatus and the distillation column can be miniaturized. SOLUTION: An alkyl-aromatic compound is oxidized with an oxygen-containing gas in the liquid phase in the presence of an oxidation catalyst in a reactional solvent containing an aliphatic carboxylic acid in an oxidation reactor 1 to produce an aromatic carboxylic acid and an oxidation waste gas is introduced into a first distillation column 2 to carry out the distillation. A waste gas from the distillation column 2 is then introduced through an intercooler 4 or a side reboiler into a second distillation column 3 to perform the distillation. The resultant fraction of the second distillation column 3 is refluxed through a pump 5 to the first distillation column 2. The fraction is taken out of a line L5 at the time of emergency stop of the apparatus to thereby prevent the reflux of the refluxing stream at a low concentration and a low temperature to the oxidation reactor 1. Thereby, the restart of the apparatus is facilitated.