CO2 capture from the atmosphere and simultaneous concentration using zeolites and amine-grafted SBA-15.
CO(2) capture from the atmosphere and concentration by cyclic adsorption-desorption processes are studied for the first time. New high microporosity materials, zeolite types Li-LSX and K-LSX, are compared to zeolite NaX and amine-grafted SBA-15 with low amine content. Breakthrough performance showed low silica type X (LSX) to have the most promise for application in dry conditions and capable of high space velocities of at least 63,000 h(-1), with minimal spreading of the CO(2) breakthrough curve. Amine-grafted silica was the only adsorbent able to operate in wet conditions, but at a lower space velocity of 1500 h(-1), due to slower uptake rates. The results illustrate that the uptake rate is as important as the equilibrium adsorbed amount in determining the cyclic process performance. Li-LSX was found to have double the capacity of zeolite NaX at atmospheric conditions, also higher than all other reported zeolites. It is further demonstrated that by using a combined temperature and vacuum swing cycle, the CO(2) concentration in the desorption product is >90% for all adsorbents in pellet form. This is the first report of such high CO(2) product concentrations from a single cycle, using atmospheric air.
Department of Chemical Engineering, University of Michigan, Ann Arbor Michigan 48105, United States.
Amy Nicki
AN
Stuckert
Department of Chemical Engineering, University of Michigan, Ann Arbor Michigan 48105, United States.
Ralph T
RT
Yang
D000588:Amines / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
D000588:Amines; C509969:SBA-15; D017641:Zeolites; D002245:Carbon Dioxide; D012822:Silicon Dioxide