Patent ID: 7919652
Filing Date: 2011-04-05
Classification: C07C

Abstract:
1. A process to produce an enriched composition comprising terephthalic acid, said process comprising: (a) subjecting a cooled carboxylic acid composition comprising terephthalic acid, and a wash feed to a catalyst removal zone in a terephthalic acid process to form a post catalyst removal composition, a wash liquor, and a catalyst rich liquor; (b) contacting an enrichment feed with said post catalyst removal composition comprising terephthalic acid, to form said enriched composition; wherein said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, and phthaldehyde isomers; wherein said enriched composition is enriched in at least one of said compounds relative to said post catalyst removal composition.