Patent ID: 7847137

Claim:
A process for xylene isomer production comprising: (a) fractionating by distillation a Xylene Loop feed comprising xylenes and C 9 + aromatics to provide a lower boiling fraction comprising xylenes and at least one higher boiling fraction comprising C 9 + aromatics; (b) separating the lower boiling fraction in at least one xylene isomer separation zone to recover a xylene isomer and provide a C 8 aromatic stream depleted in said xylene isomer; (c) isomerizing the C 8 aromatic stream depleted in said xylene isomer under isomerization conditions to provide an isomerate having a distribution of xylene isomers closer to equilibrium; (d) separating from the isomerate by fractional distillation a recycle stream comprising xylenes; (e) passing the recycle stream to step (a); (f) mixing at least a portion of the higher boiling fraction from step (a) with at least a first portion of a feedstock, said feedstock comprising an aromatic component having at least six carbon atoms and an olefin component, said mixture having an End Boiling Point of at least about 210° C. and a Bromine Index of at least about 50; (g) transalkylating said mixture under transalkylation conditions to provide a transalkylation product containing an increased amount of xylenes and having a Bromine Index at least 60% lower than the Bromine Index of the mixture, said transalkylation conditions comprising the presence of at least one of benzene and toluene and a catalyst comprising an acidic molecular sieve and at least one metal component; (h) separating from the transalkylation product by fractional distillation C 7 and lower hydrocarbons to provide a C 8 containing fraction; and (i) passing at least a portion of the C 8 containing fraction to step (a) as at least a portion of the Xylene Loop feed.