Patent ID: 7361784

Claim:
A process for producing a carboxylic acid, said process comprising: (a) introducing a feed stream comprising para-xylene into a reaction zone of an oxidation reactor; (b) introducing a solvent feed into said reaction zone, wherein at least about 20 weight percent of said solvent feed is recycled solvent, wherein said solvent feed has one or more of the following characteristics: (i) contains in the range of from about 450 to about 3,000 ppmw of aromatic carboxylic acids lacking non-aromatic hydrocarbyl groups, (ii) contains in the range of from about 120 to about 400 ppmw of isophthalic acid (IPA), (iii) contains in the range of from about 1 to about 8 ppmw of total flourenones, (iv) contains in the range of from about 0.5 to about 5 ppmw of 2,6-dicarboxyflorenone (2,6-DCF); and (c) oxidizing at least a portion of said para-xylene in a liquid phase of a multi-phase reaction medium contained in said reaction zone.