Hybrid membrane and adsorption-based system and process for recovering co2 from flue gas and using combustion air for adsorbent regeneration

A system for recovering CO2 from flue gas, comprising:

• a combustor adapted and configured to combust fuel, oxidant, and supplemental oxidant to produce a flue gas stream;
• a purification unit in fluid communication with the combustor that is adapted and configured to purify the flue gas stream and produce a purified flue gas stream;
• a first compressor in fluid communication with the purification unit that is adapted and configured to compress the purified flue gas stream;
• a gas separation membrane unit in fluid communication with the first compressor that comprising one or more gas separation membranes adapted and configured to receive a feed gas stream from the first compressor and separate the feed gas stream into a permeate gas stream and a non-permeate gas stream that is deficient in CO2 compared to the permeate gas stream;
• a second compressor in fluid communication with the gas separation membrane unit that is adapted and configured to receive and compress the permeate gas stream to produce a compressed permeate gas stream;
• at least one heat exchanger, at least one of the at least one heat exchanger being in heat transfer relation with the compressed permeate gas stream and being adapted and configured to partially condense the compressed permeate gas stream to produce a partially condensed permeate stream, at least one of the at least one heat exchanger being in heat transfer relation with the feed gas stream;
• a PSA unit comprising one or more adsorbent beds in fluid communication with the gas separation membrane unit that is adapted and configured to receive the non-permeate gas stream and an air stream and produce a CO2 blow-down gas stream enriched in CO2 compared to the non-permeate gas stream, a further CO2-depleted vent gas stream, and a regeneration product stream, the one or more adsorbent beds being adapted and configured to adsorb CO2 from the non-permeate stream, the regeneration product stream comprising air and CO2 desorbed from the one or more adsorbent beds by the air stream, the combustor being further adapted and configured to receive the regeneration product stream from the PSA unit, the first compressor being further adapted and configured to compress the CO2 blow-down stream along with the purified flue gas stream;
• and
• a phase separation unit in fluid communication with the second compressor that is adapted and configured to receive the partially condensed permeate stream from the heat exchanger and separate the partially condensed permeate stream into a CO2-deficient vent gas stream deficient in CO2 compared to partially condensed permeate stream and a high purity liquid CO2 stream, wherein the feed gas is a combination of the compressed purified flue gas and the CO2-deficient vent gas stream.