Patent ID: 7439409
Filing Date: 2008-10-21
Classification: C07C

Abstract:
1. A process combination for the production of high-purity para-xylene from an isobutane concentrate comprising the steps of: a) contacting the isobutane concentrate with a dehydrogenation catalyst in a dehydrogenation zone operating at dehydrogenation conditions to produce hydrogen and a dehydrogenation product stream comprising isobutene; b) contacting at least a portion of the dehydrogenation product stream with a dimerization catalyst in a dimerization zone operating at dimerization conditions to produce a butene dimer comprising one or both of C c) contacting at least a portion of the butene dimer with a non-zeolitic aromatization catalyst in an aromatization zone operating at aromatization conditions to produce an para-xylene concentrate comprising xylenes having a higher-than-equilibrium content of para-xylene; and, d) passing at least a portion of the para-xylene concentrate to a para-xylene purification zone operating at purification-zone conditions to recover high-purity para-xylene; wherein the aromatization catalyst comprises: 1) a support comprising an oxide of a metal selected from one or more of alumina, titania and zirconia; 2) a hydrogenation metal selected from one or more of the platinum-group metals; 3) a metal modifier selected from one or more of tin, indium, germanium, gallium, copper, silver, gold, lead, zinc and the rare-earth elements; and, 4) one or more of the alkali and alkaline earth metals.