Patent ID: 7902396

Claim:
A process for producing terephthalic acid, said process comprising: (a) introducing a feed stream comprising para-xylene into a reaction zone of a oxidation reactor, wherein said feed stream has one or more of the following characteristics— (i) contains meta-xylene in an amount in the range of from about 20 to about 800 parts per million by weight of said para-xylene (ppmw pX ), (ii) contains meta-xylene, orthoxylene, ethylbenzene, and toluene, in combination, in an amount in the range of from about 50 to about 900 ppmw pX ; (b) oxidizing at least a portion of said para-xylene in a liquid phase of a multi-phase reaction medium contained in said reaction zone, wherein said oxidizing causes the formation of crude terephthalic acid in said reaction zone (c) oxidizing at least a portion of said crude terephthalic acid in a secondary oxidation reactor to thereby form purer terephthalic acid.