Patent ID: 7897809

Claim:
A process to produce an enrichment feed, said process comprising: (a) subjecting a solvent rich stream produced in a terephthalic acid production process to a solids concentration zone to form a concentrated solvent rich stream; wherein said solvent rich stream comprises at least one solvent, at least one carboxylic acid, and at least one oxidation byproduct; wherein said solvent rich stream has a solids content of less than 5% by weight; wherein the quantity of solids in said concentrated solvent rich stream is higher than the quantity of solids from said solvent rich stream on a weight basis; (b) subjecting said concentrated solvent rich stream to a concentrated SLS zone (a solid-liquid separation zone) to form a mother liquor stream and an enrichment feed; wherein said concentrated SLS zone comprises at least one solid liquid separation device; and (c) recycling at least a portion of said enrichment feed to any point in a TPA production process after a primary oxidation zone and before a drying zone.