Integration of pressure swing adsorption with an electric power plant for CO2 capture / use and N2 production

摘要

A method for the production of N2 and CO2 from a reactor exhaust stream, comprising: passing a reactor exhaust stream comprising at least 70% by volume of N2 and at least 10% by volume of CO2 in an oscillation adsorption reactor comprising an adsorbent material, including a mixture of an alkali metal carbonate and an alkaline earth metal oxide and / or a transition metal oxide, the reactor exhaust stream having a pressure of between 10 bara (1.0 MPaa) and 30 bara (3.0 MPaa); adsorb CO2 on the adsorbent material at an adsorption temperature of at least 400 ° C; recovering a stream of N2 with a purity of at least 95% by volume from a front end of the reactor, the recovered N2 stream having a pressure that differs from the pressure of the reactor exhaust stream by 0.5 bar (50 kPa) or less; reduce the pressure in the swing adsorption reactor to a pressure of from 1.0 bara (0.1 MPaa) to 3.0 bara (0.3 MPaa) by producing a blow-down stream from at least one end of the reactor ; purge the adsorption reactor by oscillation with a steam purge at a pressure of from 1.0 bara (0.1 MPaa) to 3.0 bara (0.3 MPaa) to generate a CO2 recovery stream, the CO2 recovery comprising at least 90% of the CO2 present in the reactor exhaust stream, the steam vent containing less than 1.0 mole of H2O per mole of CO2 in the reactor exhaust stream; and optionally further comprising passing a second blowdown stream through the oscillation adsorption reactor to generate a second CO2 recovery stream, the second blowdown stream having a different composition than the steam blowdown, in which the Step, adsorption, recovery, reduction and blowdown comprise a pressure swing adsorption cycle, and corresponding reactor exhaust stream, steam blowdown and second blowdown stream, if used, correspond to the minus 95 volume% of all gas flows introduced into the swing adsorption reactor during the pressure swing adsorption cycle.