Patent ID: 7642393

Claim:
A method of diverting at least benzene from a hydrocarbon stream and enhancing the recovery of benzene and toluene from the diverted stream comprising: concentrating aromatics in the hydrocarbon stream by passing the hydrocarbon stream directly from a reformer through a membrane unit having at least one membrane to produce a permeate stream and a retentate stream, wherein the permeate stream is aromatics rich relative to the hydrocarbon stream and wherein the membrane comprises a polymer; feeding the permeate stream to a pre-fractionation column operated with a top, middle and bottom cut and feeding the middle cut of the pre-fractionation column to an extraction unit; extracting aromatics from the middle cut using a selective aromatics extraction solvent in an extraction unit to produce an extract stream, wherein the extract stream is aromatics rich relative to the permeate stream; fractionating the extract stream in a benzene distillation device to produce a benzene overhead stream and a benzene bottom stream, wherein the benzene overhead stream is rich in benzene relative to the extract stream; fractionating the benzene bottom stream in a toluene distillation device to produce a toluene overhead stream and a toluene bottom stream, wherein the toluene overhead stream is rich in toluene relative to the benzene bottom stream; and fractionating the toluene bottom stream in a xylene distillation device to produce a xylene overhead stream and a xylene bottom stream, wherein the xylene overhead stream is rich in xylene relative to the toluene bottom stream.