Patent ID: 7410632

Claim:
A process comprising the following steps: (a) evaporating a mother liquor comprising a carboxylic acid, a metal catalyst, impurities, water and a solvent in a first evaporator zone to produce a vapor stream and a concentrated mother liquor stream; (b) evaporating said concentrated mother liquor stream in a second evaporator zone to form a solvent rich stream and a super concentrated mother liquor stream; (c) separating organic impurities with a water-solvent solution from said super concentrated mother liquor stream in a solid-liquid separation zone to form an aqueous stream and a second aqueous stream; (d) mixing in a mixing zone water and optionally an extraction solvent with said aqueous stream and said second aqueous stream to form an aqueous mixture; (e) adding an extraction solvent to said aqueous mixture in an extraction zone to form an extract stream and a raffinate stream; and (f) optionally separating said extract stream in a separation zone to form a high boiling point organic impurities stream and a recovered extraction solvent stream.