Patent ID: 8034168

Claim:
A combustion system adapted to control carbon dioxide emissions, comprising: (a) a combustion unit configured to combust a mixture of fuel and air, oxygen-enriched air, or oxygen, thereby producing an exhaust stream containing carbon dioxide; (b) a carbon dioxide capture unit configured to accept a first portion of the exhaust stream and remove a portion of carbon dioxide in concentrated form; and (c) a sweep-based membrane separation unit configured to accept a second portion of the exhaust stream, where the membrane separation unit comprises (i) at least one membrane having a feed side and a permeate side, where the at least one membrane is selectively permeable to carbon dioxide over nitrogen and to carbon dioxide over oxygen, (ii) means for passing the second portion across the feed side of the at least one membrane, (iii) means for passing air, oxygen-enriched air, or oxygen as a sweep stream across the permeate side of the at least one membrane, (iv) means for withdrawing from the feed side of the at least one membrane a carbon-dioxide depleted vent stream, and (v) means for withdrawing from the permeate side of the at least one membrane a permeate stream comprising oxygen and carbon dioxide, and to pass the permeate stream to the combustion unit as at least part of the air, oxygen-enriched air, or oxygen to the combustion unit.