Patent ID: 6361583
Filing Date: 2002-03-26
Classification: B01D,Y02C

Abstract:
A process for separating a desired gas from a gas mixture comprising the desired gas and a C3+ hydrocarbon vapor, the process comprising the steps of:(a) bringing the gas mixture into contact with the feed side of a separation membrane having a feed side and a permeate side, the separation membrane having a selective layer comprising: a polymer comprising repeat units of a fluorinated cyclic structure of an at least 5-member ring, the polymer having a fractional free volume no greater than about 0.3; (b) providing a driving force for transmembrane permeation; (c) withdrawing from the permeate side a permeate stream enriched in the desired gas compared to the gas mixture; (d) withdrawing from the feed side a residue stream depleted in the desired gas compared to the gas mixture.