Patent ID: 6171472
Filing Date: 2001-01-09
Classification: C10G

Abstract:
A process for use in a refinery, petrochemical plant or the like, comprising providing selective purging of light hydrocarbons from a reactor recycle loop by carrying out the following steps:(a) withdrawing an effluent stream comprising hydrogen and hydrocarbons from a reactor in the reactor recycle loop;(b) separating a vapor phase comprising hydrogen and light hydrocarbons, including a C.sub.4+ hydrocarbon, from the effluent stream;(c) passing at least a portion of the vapor phase as a feed stream across the feed side of a polymeric membrane having a feed side and permeate side, and being selective for the C.sub.4+ hydrocarbon over hydrogen;(d) withdrawing from the permeate side a permeate stream enriched in the C.sub.4+ hydrocarbon compared with the vapor phase;(e) withdrawing from the feed side a residue stream enriched in hydrogen compared with the vapor phase;(f) completing the reactor recycle loop by recirculating at least a portion of the residue stream to the reactor.