Separation process combining condensation, membrane separation and flash evaporation
AssigneeMembrane Technology and Research, Inc.
InventorsRichard W. Baker, Kaaeid A. Lokhandwala, Douglas Gottschlich, Marc L. Jacobs
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Abstract
A process for separating two low-boiling components of a gas-phase mixture. The invention involves three separation steps: condensation, flash evaporation and membrane separation. The steps are integrated together in such a way as to provide a good separation between the components, and to avoid creation of secondary streams that need additional treatment. The invention is particularly useful for separation of low molecular weight organic compounds from other gases.
Claims57
A process for separating a higher-boiling and a lower-boiling component of a gaseous mixture, both components having boiling points at atmospheric pressure below 0.degree. C., said process comprising the following steps:
- (a) cooling said gaseous mixture to a temperature no lower than about -100.degree. C., resulting in partial condensation of said gaseous mixture, thereby dividing said gaseous mixture into a condensed portion enriched in said higher-boiling component and an uncondensed portion enriched in said lower-boiling component;
- (b) flash evaporating said condensed portion to at least partially remove additional amounts of said lower-boiling component from said condensed portion as a gaseous flash stream, thereby creating a more-enriched higher-boiling component product stream;
- (c) membrane treating said uncondensed portion in a membrane separation unit, to further divide said uncondensed portion into a more-enriched lower-boiling component stream and a mixed stream;
- (d) recirculating said mixed stream to said cooling step.
A process for separating a higher-boiling and a lower-boiling component of a gaseous mixture, both components having boiling points at atmospheric pressure below 0.degree. C., said process comprising the following steps:
- (a) cooling said gaseous mixture to a temperature no lower than about -100.degree. C., resulting in partial condensation of said gaseous mixture, thereby dividing said gaseous mixture into a condensed portion enriched in said higher-boiling component and an uncondensed portion enriched in said lower-boiling component;
- (b) flash evaporating said condensed portion to at least partially remove additional amounts of said lower-boiling component from said condensed portion as a gaseous flash stream, thereby creating a more-enriched higher-boiling component product stream;
- (c) membrane treating said uncondensed portion in a membrane separation unit, to further divide said uncondensed portion into a more-enriched lower-boiling component stream and a mixed stream;
- (d) recirculating said gaseous flash stream to said cooling step.
A process for separating a higher-boiling and a lower-boiling component of a gaseous mixture, both components having boiling points at atmospheric pressure below 0.degree. C., said process comprising the following steps:
- (a) cooling said gaseous mixture, said cooling being provided at least in part by heat exchange against at least one colder stream, to a temperature no lower than about -100.degree. C., resulting in partial condensation of said gaseous mixture, thereby dividing said gaseous mixture into a condensed portion enriched in said higher-boiling component and an uncondensed portion enriched in said lower-boiling component;
- (b) flash evaporating said condensed portion to at least partially remove additional amounts of said lower-boiling component from said condensed portion as a gaseous flash stream, thereby creating a more-enriched higher-boiling component product stream;
- (c) membrane treating said uncondensed portion in a membrane separation unit, to further divide said uncondensed portion into a more-enriched lower-boiling component stream and a mixed stream;
- (d) recirculating said mixed stream upstream of said cooling step;
- wherein said at least one colder stream is selected from the group consisting of said more-enriched lower-boiling component stream, said mixed stream and said more-enriched higher-boiling component product stream.
Dependencies are inferred from the claim text.