Xylene isomerization

Abstract

A process for producing xylenes, in particular para-xylene that is less energy intensive than conventional processes is provided. In an embodiment the process comprises contacting a feed mixture in an isomerization zone with a catalyst at isomerization conditions and producing an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein the catalyst comprises an acidic sulfonated catalytic membrane. Xylene isomerization can also be coupled with a p-xylene extraction process, where the raffinate (p-xylene deprived stream) from the extraction process is fed to an isomerization reactor to produce p-xylene. In an embodiment, the process can comprise: a) providing a feed stream comprising a mixture of xylene isomers including p-xylene; b) extracting p-xylene from the feed stream using a separator to separate the feed stream into a p-xylene rich stream and a p-xylene deprived stream; and c) delivering the p-xylene deprived stream to an isomerization unit, the isomerization unit including an acidic sulfonated catalytic membrane, and using the isomerization unit to produce an isomerized product comprising a higher proportion of p-xylene than in the p-xylene deprived stream delivered to the isomerization unit. In any one or more aspects, the isomerization unit can be operated at a temperature in the range of less than 350°, for example about 20° C. to about 200° C.