Membrane capture of co2 from refinery emissions
AssigneeChevron U.S.A. Inc.
InventorsDaniel CHINN, Nitesh BHUWANIA, Zunqing HE
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Abstract
The present invention is directed to a method of capturing CO2 from, for example, a FCC regenerator or other CO2 production, using select membranes. In some embodiments, a flowrate of a counter-current air sweep is adjusted to maintain about the same or higher percentage of excess oxygen as, for example, an FCC regenerator. In some embodiments, a portion of combustion air for the FCC regenerator may be replaced by C02-enriched, oxygen-depleted air sweep from a membrane operating with counter-current air sweep.
Claims24
A method for capturing CO2 produced from a FCC regenerator flue gas comprising,
- treating the flue gas with a crossflow membrane and then treating at least a portion of the crossflow membrane treated flue gas with a second membrane comprising a counter-current air sweep on the permeate side;
- and
- liquefying CO2 in a permeate from the crossflow membrane to produce a liquefied CO2 and a CO2-rich vapor;
- (a) wherein a flowrate of the counter-current air sweep is adjusted to maintain about the same percentage of excess oxygen as an FCC regenerator;
- or
- (b) wherein a portion of combustion air for the FCC regenerator is replaced by CO2-enriched, oxygen-depleted air sweep from the membrane operating with counter-current air sweep;
- or
- (c) both (a) and (b).
A method for capturing CO2 produced from a generated gas comprising,
- treating the generated gas with a crossflow membrane and then treating at least a portion of the crossflow membrane treated generated gas with a second membrane comprising a counter-current air sweep on the permeate side;
- and
- liquefying CO2 in a permeate from the crossflow membrane to produce a liquefied CO2 and a CO2-rich vapor;
- wherein an amount of CO2 in the generated gas is from about 8% to about 20% and wherein the generated gas is from a combustion;
- (a) wherein a flowrate of the counter-current air sweep is adjusted to maintain about the same or higher percentage of excess oxygen as that being combusted in the combustion;
- or
- (b) wherein a portion of combustion air for the combustion is replaced by CO2-enriched, oxygen-depleted air sweep from the membrane operating with counter-current air sweep;
- or
- (c) both (a) and (b).
Dependencies are inferred from the claim text.