Patent ID: 7897810

Claim:
A process comprising: (a) introducing a liquid-phase medium into an evaporation zone, wherein said liquid-phase medium comprises a mother liquor and terephthalic acid; (b) evaporating at least a portion of said mother liquor from said liquid-phase medium to thereby form a concentrated medium, wherein said concentrated medium comprises an unevaporated portion of said mother liquor and substantially all of said terephthalic acid; (c) displacing at least a portion of said unevaporated mother liquor with a wash medium, thereby providing a hydrogenation medium comprising at least a portion of said wash medium and at least a portion of said terephthalic acid; and (d) subjecting at least a portion of said hydrogenation medium to hydrogenation treatment, thereby forming a hydrogenation-treated medium; wherein said process further comprises producing a slurry from an initial oxidation reactor, wherein said slurry comprises an initial oxidation liquid and an initial oxidation solid phase, wherein at least a portion of said liquid-phase medium of step (a) originates from said initial oxidation liquid phase; and wherein said process further comprises recovering unhydrogenated terephthalic acid particles originating from said initial oxidation solids phase, and wherein said process further comprises recovering hydrogenation-treated terephthalic acid particles originating from said hydrogenation-treated medium; wherein said hydrogenation medium comprises at least a portion of said solid particles of said terephthalic acid; wherein the weight ratio of said oxidation-treated terephthalic acid particles to said hydrogenation-treated terephthalic acid particles in said composite terephthalic acid product is in the range of from about 10:1 to about 1,000:1; and wherein the weight ratio of said oxidation-treated terephthalic acid particles to said hydrogenation-treated terephthalic acid particles in said composite terephthalic acid product is in the range of from 50:1 to 250:1.