Adsorption of CO2 on molecular sieves and activated carbon

Pressure swing adsorption (PSA) and temperature swing adsorption (TSA) are some of the potential techniques that could be applicable for removal of CO 2 from high-pressure fuel gas streams. Molecular sieves and activated carbo ns are some of the sorbents that could be utilized in the PSA process. Volu metric adsorption studies of CO2, N-2, or H-2 on molecular sieve 13X, molec ular sieve 4A, and activated carbon were conducted at 25 degreesC up to a p ressure of 300 psi (similar to 2x 106 Pa). Preferential. adsorption of CO2 was observed with all three sorbents. The adsorption capacity of CO2 for mo lecular sieve 13X was higher than that for molecular sieve 4A at all pressu res up to 300 psi: At law pressures (<25 psi) the adsorption capacity for C O2 of activated carbon was lower,than that of molecular sieve 13X, but at h igher pressures (>25 psi) activated carbon exhibited significantly higher C O2 capacities than were found for molecular sieves. Competitive adsorption of CO2 from gas mixtures also indicated that both molecular sieve 13X and a ctivated carbon can be utilized for separation of CO2 from-gas mixtures.