Patent ID: 7855305
Filing Date: 2010-12-21
Classification: C07C

Abstract:
1. A process to produce an enriched composition suitable for use in the production of step-growth polymers, said process comprising: a) oxidizing an aromatic feedstock comprising para-xylene in a primary oxidation zone to form a crude carboxylic acid composition comprising terephthalic acid; b) optionally subjecting said crude carboxylic acid composition to a liquid displacement zone to form a slurry composition; c) crystallizing said slurry composition or said crude carboxylic acid composition in a crystallization zone to form a crystallized slurry composition; d) cooling and optionally enriching said crystallized slurry composition in a cooling zone to form a cooled carboxylic acid composition; e) subjecting said cooled carboxylic acid composition to a wash feed comprising acetic acid in a catalyst removal zone to form a post catalyst removal composition, a wash liquor, and a catalyst rich liquor; and f) contacting said post catalyst removal composition with an enrichment feed in an enrichment zone to form said enriched composition, said enrichment feed comprising 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.