Patent ID: 6254666
Filing Date: 2001-07-03
Classification: B01D,C07C,Y02C,Y02P

Abstract:
A process for the separation and recovery of perfluorocompound gases from a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said process comprising the steps of:(a) providing a first membrane having a feed side and a permeate side, the first membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;(b) contacting the feed side of the first membrane with the gas mixture;(c) withdrawing from the feed side of the first membrane a first non-permeate stream enriched in the at least one perfluorocompound gas;(d) withdrawing from the permeate side of the first membrane a first permeate stream comprising primarily the at least one carrier gas;(e) providing a second membrane having a feed side and a permeate side, the second membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;(f) contacting the feed side of the second membrane with the first non-permeate stream;(g) withdrawing from the feed side of the second membrane a second non-permeate stream enriched in the at least one perfluorocompound gas;(h) withdrawing from the permeate side of the second membrane a second permeate stream comprising primarily the at least one carrier gas;(i) passing the second non-permeate stream to a condensation process to liquefy at least a portion of the perfluorocompound gas; and(j) recycling at least a portion of the second permeate stream to the feed side of the first membrane.