Process for oxidizing impurities in crude terephthalic acid
||WO 2014058943 A1
||Oct 9, 2013
||Apr 17, 2014
A process for oxidizing solid crude terephthalic acid is described. The process includes contacting solid crude terephthalic acid with a solvent comprising a carboxylic acid and one or more of an ionic liquid or ammonium acetate; a bromine source; a catalyst; and an oxidizing agent to produce solid purified terephthalic acid at a temperature of 100 to 210°C, and a pressure of 2 to 4.5 MPa, for a time of 5 to 60 min, and recovering the solid purified terephthalic acid.