CONCENTRATION AND RECOVERY OF CO2 FROM FLUE-GAS BY PRESSURE SWING ADSORPTION

The feasibility of recovering CO2 from flue gas to generate a high-purity product by pressure swing adsorption (PSA) is studied by simulation using a proven predictive PSA model. Two promising sorbents, activated carbon and carbon molecular sieve, are examined. A nonconventional PSA cycle is designed for this purpose. With activated carbon as the sorbent, CO2 Can be concentrated from 17 % in the flue gas to a product of 99.997 % (at a CO2 recovery of 68.4 % and at a reasonably high feed throughput). Despite the favorable kinetic selectivity for CO2 in the carbon molecular sieve, separation results using this sorbent are not as good, because the kinetic selectivity (of CO2/N2) is not high enough and consequently the equilibrium selectivity dominates the separation.