Process for recovering SF6 from a gas
AssigneeAmerican Air Liquide, Inc.
InventorsYao-En Li, Magdy Meimari
Life of this patent
Estimating the term…
Abstract
A process for recovering SF.sub.6 from a gas is provided. The process includes the step of contacting a gas stream comprising SF.sub.6 and at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O with a membrane in at least one membrane separation unit at conditions effective to obtain a retentate stream rich in SF.sub.6 and a permeate stream rich in at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O.
Claims24
A process for forming solidified Mg metal, said process comprising the steps of:
- (a) casting molten Mg metal in a gaseous atmosphere comprising SF.sub.6 ;
- (b) cooling said molten Mg metal to form a solidified Mg metal;
- (c) obtaining a vent gas comprising SF.sub.6 and at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O from said casting step;
- and
- (d) contacting said vent gas with a membrane in at least one membrane separation unit at conditions effective to obtain a retentate stream rich in SF.sub.6 and a permeate stream rich in at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O.
A process for forming solidified Mg metal, said process comprising the steps of:
- (a) casting molten Mg metal in a gaseous atmosphere comprising SF.sub.6 and CO.sub.2 ;
- (b) cooling said molten Mg metal to form a solidified Mg metal;
- (c) obtaining a vent gas comprising SF.sub.6 and CO.sub.2 from said casting step;
- and
- (d) contacting said vent gas with a membrane in two or more membrane separation units at conditions effective to obtain a retentate stream rich in SF.sub.6 and a permeate stream rich in CO.sub.2.
A process for forming solidified Mg metal, said process comprising the steps of:
- (a) casting molten Mg metal in a gaseous atmosphere comprising SF.sub.6 and CO.sub.2 ;
- (b) cooling said molten Mg metal to form a solidified Mg metal;
- (c) obtaining a vent gas comprising SF.sub.6 and CO.sub.2 from said casting step;
- (d) contacting said vent gas 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 ;
- (e) contacting said first permeate stream with a second membrane in a second membrane separation unit at conditions effective to obtain a second retentate stream depleted in CO.sub.2 and a second permeate stream rich in CO.sub.2 ;
- and
- (f) contacting said first 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.
Dependencies are inferred from the claim text.