Patent ID: 9000247
Filing Date: 2015-04-07
Classification: B01J,C07C,C10G

Abstract:
1. A method of forming mixed xylenes from a heavy reformate using a dealkylation-transalkylation system, the method comprising the steps of: introducing both the heavy reformate and a hydrogen-containing material into a dealkylation stage of the dealkylation-transalkylation system such that the heavy reformate and the hydrogen-containing material intermingle and contact a hydrodealkylation catalyst, where the dealkylation stage contains the hydrodealkylation catalyst, where the heavy reformate comprises a significant amount of both methyl ethyl benzenes and tri-methyl benzenes and is substantially free of toluene by weight, and where the hydrogen-containing material comprises hydrogen; operating the dealkylation stage such that toluene forms from the reaction methyl ethyl benzenes and hydrogen in the presence of the hydrodealkylation catalyst and such that a dealkylation stage product is produced, where the dealkylation stage product comprises toluene, tri-methyl benzenes and non-aromatic product gas; operating the non-aromatic product gas separations stage such that the non-aromatic product gas and a dealkylation heavy reformate are produced separately and the non-aromatic product gas from the dealkylation stage product is removed before it is introduced into the vessel where transalkylation occurs, where the dealkylation heavy reformate comprises toluene and tri-methyl benzenes; introducing the dealkylated heavy reformate into the transalkylation stage such that the dealkylated heavy reformate contacts a transalkylation catalyst, where the transalkylation stage contains the transalkylation catalyst; and operating the transalkylation stage such that mixed xylenes form from reaction of tri-methyl benzenes and toluene in the presence of the transalkylation catalyst and such that a transalkylation stage product is produced, where the transalkylation stage product mixture comprises xylenes.