Patent ID: 7638669
Filing Date: 2009-12-29
Classification: C07C,Y02P

Abstract:
1. A process for transalkylation and disproportionation comprising: a. passing a lighter aromatic stream containing at least one of benzene and toluene and a heavier aromatic stream containing C b. subjecting said lighter aromatic stream and said heavier aromatic stream in said transalkylation zone to transalkylation conditions including the presence of a metal-stabilized transalkylation catalyst to provide a transalkylation product stream having a greater concentration of toluene and C c. separating by fractionation from said transalkylation product stream a lower boiling fraction comprising benzene and at least about 10 mass percent of the toluene in transalkylation product stream and a higher boiling fraction comprising toluene and C d. recycling at least a portion of the lower boiling fraction from step c to step b sufficient to maintain a benzene to total aromatics mole ratio to step b at least about 0.2:1; e. passing at least a portion of the higher boiling fraction from step c to a disproportionation zone at disproportionation condition including the presence of a disproportionation catalyst to generate a disproportion product; f. subjecting at least a portion of the higher boiling fraction comprising C8 aromatics of step c to a separation to selectively remove one or more of para-xylene and ortho-xylene as xylene products and provide a non-equilibrium mixture of C8 aromatics; g. subjecting the non-equilibrium mixture of C8 aromatics to xylene isomerization conditions including the presence of isomerization catalyst to provide an isomerization product containing benzene and a greater concentration of said xylene isomer selectively removed in step f; and h. separating the isomerization product by fractionation into a lower boiling, benzene-containing fraction at least a portion of which is recycled to step b and a higher boiling C8 aromatics-containing fraction at least a portion of which is recycled to step f.