Patent ID: 7381858

Claim:
A process for recovering meta-xylene in admixtures with other C 8 aromatic compounds which process comprises: (1-A) withdrawing from a perm-selective membrane device a first fluid stream having an enriched content of meta-xylene compared to that of a second effluent stream which streams are derived by selective permeation of at least one C 8 aromatic compound from a fluid mixture comprising meta-xylene and one or more other aromatic compound utilizing perm-selective membranes comprising at least one poly(amide)imide material having an average molecular weight between 20,000 and 200,000 which polymeric materials under suitable driving force exhibit a permeability of at least 0.1 Barrer for at least one of the isomers of xylene or ethylbenzene; (1-B) distributing all or portion of the first stream withdrawn from the membrane device into meta-xylene recovery operation to extract therefrom a purified product having an enriched content of the meta-xylene compared to that of first stream, and a reject stream lean in meta-xylene; and (1-C) passing at least a portion of the reject stream to a catalytic conversion process to produce a stream comprising an equilibrium mixture of xylenes.