Patent ID: 6896717
Filing Date: 2005-05-24
Classification: B01D

Abstract:
1. A gas separation process, comprising: (a) providing a membrane having a feed side and a permeate side and comprising; (i) a base membrane comprising a selective layer of a first polymer on the feed side, and (ii) a C wherein, when measured under the same conditions and in the absence of C wherein the second polymer has a fractional free volume no greater than about 0.3 and a glass transition temperature of at least about 100° C., and is chosen from the group consisting of (I) polymers comprising repeating units having a fluorinated cyclic structure of an at least 5-member ring and (II) polymers having a ratio of fluorine to carbon atoms in the polymer greater than 1:1; (b) passing a gas mixture comprising a first gas that is not a C (c) providing a driving force for transmembrane permeation; (d) withdrawing from the permeate side a permeate stream enriched in the first gas compared to the gas mixture; (e) withdrawing from the feed side a residue stream depleted in the first gas compared to the gas mixture.