Patent ID: 7759516
Filing Date: 2010-07-20
Classification: C07C

Abstract:
1. In a process for producing a terephthalic acid combined stream that employs recycling of a mother liquor and/or a wash liquor to an oxidation section of said process, the improvement comprising: (a) introducing at least a portion of said mother liquor and/or wash liquor into a purge section of said process as a purge feed stream, wherein said purge feed stream comprises impurities and one or more catalyst components; and (b) separating said purge feed stream into a: wherein said mono-functional impurity depleted stream comprises isophthalic acid, phthalic acid (PA), trimellitic acid, 2,5,4′-tricarboxybiphenyl, 2,5,4′-tricarboxybenzophenone, naphthalene dicarboxylic acid, and/or dicarboxyfluorenones; and a portion of said mono-functional impurity depleted stream is subsequently combined with a terephthalic acid product stream to form a terephthalic acid combined stream.