Patent ID: 7420082

Claim:
A process for making a terephthalic acid composition, said process comprising: (a) introducing a solvent feed into a primary oxidation reaction zone, wherein at least 20 weight percent of said solvent feed is recycled solvent; (b) subjecting an oxidizable compound to oxidation in said primary oxidation zone to thereby produce an initial slurry comprising an initial solid comprising terephthalic acid and an initial liquid, wherein a representative sample of said slurry has at least three of the following characteristics based on the combined solid and liquid slurry components: (i) contains less than 9,000 ppmw of isophthalic acid (IPA), (ii) contains less than 15,000 ppmw of benzoic acid (BA), (iii) contains less than 64 ppmw of 4,4′-dicarboxybiphenyl (4,4′-DCB), (iv) contains less than 70 ppmw of 2,6-dicarboxyfluorenone (2,6-DCF), (v) contains less than 12 ppmw of 2,7-dicarboxyfluorenone (2,7-DCF), (vi) contains less than 12 ppmw of 9-fluorenone-2-carboxylic acid (9F-2CA), (vii) contains less than 4 ppmw of 4,4′-dicarboxystilbene (4,4′-DCS), (viii) contains less than 6 ppmw of 4,4′-dicarboxyanthraquinone (4,4′-DCA); and (c) cooling at least a portion of an oxidation product slurry in an optimized cooling zone to a cooled temperature in the range of from about 60 to about 200° C. to thereby produce a cooled slurry, wherein said oxidation product slurry contains at least 30 weight percent of said initial liquid.