Patent ID: 6096114
Filing Date: 2000-08-01
Classification: B01D,Y02C

Abstract:
A process for separating SF.sub.6 from CO.sub.2, said process comprising the steps of:(a) contacting a feed gas stream comprising SF.sub.6 and CO.sub.2 with a first membrane in a first membrane separation unit at conditions effective to obtain a first retentate stream rich in SF.sub.6 and a first permeate stream rich in CO.sub.2 ;(b) contacting said first retentate stream with a second membrane in a second membrane separation unit at conditions effective to obtain a second retentate stream rich in SF.sub.6 and a second permeate stream depleted in SF.sub.6 ;(c) contacting said second retentate stream with a third membrane in a third membrane separation unit at conditions effective to obtain a third retentate stream rich in SF.sub.6 and a third permeate stream depleted in SF.sub.6 ; and(d) recycling at least a portion of said third permeate stream to said feed gas stream or said first retentate stream, or both.