Sorption-enhanced steam-methane reforming: CaO-CaCO3 Capture technology

Calcium oxide (CaO) has been investigated in the context of CO2 capture. In its application for the sorption-enhanced steammethane reforming process (SE-SMR), CO2 is captured in a sorption mode through the formation of CaCO3, at which stage, the conversion of CH4 to H-2 is also enhanced. Subsequently, the CO2 is released in a separate desorption mode where the CaCO3 is calcined to CaO. In a combined system modeling and experimental approach a sweet-spot in operational conditions has been determined in terms of adsorption-reaction and desorption temperature and pressure. Additionally the required performance in terms of cyclic capacity has been determined in relation to system efficiency. Long term cyclic capacity under sweet-spot conditions has been demonstrated in a lab-scale experiment in excess of 200 loading cycles, with stabilization of cyclic capacity occurred after 100 cycles, and above the required minimum of 15% of the thermodynamic capacity. Increasing the adsorption temperature above 600 degrees C reactivated the CaO-CaCO3 sorbent system. (C) 2009 Elsevier Ltd. All rights reserved.