Kevin T Callaghan

US Patent:

6478852, Nov 12, 2002

Filed:

Feb 18, 2000

Appl. No.:

09/506636

Inventors:

Kevin Patrick Callaghan - Wilmington DE
Stuart Marshall Nemser - Wilmington DE

Assignee:

CMS Technology Holdings, Inc. - Wilmington DE

International Classification:

B01D 5322

US Classification:

95 54, 96 8, 96 13

Abstract:

A membrane separation process and apparatus for carrying out the process involves contacting a gas feed mixture with one side of a selectively gas permeable membrane and allowing the components to pass through the membrane to form a permeate composition in contact with the opposite side of the membrane and leave a retentate composition on the feed side of the membrane. The process includes introducing a sweep flow of feed gas into the permeate composition near the membrane at a rate effective to increase the enrichment of the retentate composition in the less preferentially permeable component of the feed mixture to a concentration much greater than is achieved without the sweep flow. This process is especially well suited to improve single stage membrane separation effectiveness so that the need for conventional multistage separations to achieve moderate to high purity retentate compositions can be obviated. The novel process is particularly useful for providing enriched air in the concentration range of 80-90 vol. % nitrogen.

US Patent:

59607777, Oct 5, 1999

Filed:

Feb 20, 1998

Appl. No.:

9/027035

Inventors:

Stuart Marshall Nemser - Wilmington DE
Kevin Patrick Callaghan - Wilmington DE
Todd Colin Reppert - Elkton MD

Assignee:

Compact Membrane Systems, Inc. - Wilmington DE

International Classification:

F02B 2300

US Classification:

123585

Abstract:

A novel method of operating an internal combustion engine employs a selectively gas permeable membrane to provide either oxygen or nitrogen enriched air feed to beneficially affect engine performance. By feeding enriched air from a membrane unit such performance parameters as reduced NOx emissions, lean burn limit, engine power, and reduced cold start emissions can be enhanced relative to feeding ambient air. The selectively gas permeable membrane unit further includes a nonporous membrane (i) having an oxygen/nitrogen selectivity of at least 1. 4 and a permeability to oxygen of at least 50 barrers; (ii) formed from an amorphous copolymer of perfluoro-2,2-dimethyl-1,3-dioxole; and (iii) being at a temperature below the glass transition temperature of the amorphous copolymer. A cylindrical module having many substantially parallel aligned small diameter hollow fiber membrane structures is ideally suited for carrying out the novel method. The apparatus can be configured to furnish only one of permeate fraction, oxygen enriched air or retentate fraction, nitrogen enriched air.