| Abstract
| - Calcium oxide is a promising sorbent for the capture of carbon dioxide. In this work, CaO sorbents wereprepared using different precursors, including Ca(NO3)2·4H2O, CaO, Ca(OH)2, CaCO3, and Ca(CH3COO)2·H2O. Of these, the sorbent prepared from calcium acetate (CaAc2−CaO) resulted in the best uptakecharacteristics for CO2. This sorbent had a higher BET surface area and larger pore volume than the othersorbents. According to SEM images, this sorbent exhibits a “fluffy” structure, which probably contributes toits high surface area and large pore volume. This sorbent also showed almost 100% carbonation, at temperaturesbetween 550 and 800 °C. Moreover, the carbonation progressed dominantly during an initial short period.Under numerous carbonation/decarbonation cycles, the CaAc2−CaO sorbent demonstrated the best reversibility,even in the presence of 10 vol % water vapor. During a 27-cycle operation, the sorbent maintained fairlyhigh conversion of 62 mol % at 700 °C. Pore size distribution measurements indicate that the pore volumedecreased as the experimental cycles continued. Silica was doped on the CaAc2−CaO sorbent in variousweight percentages, but the resultant sorbents did not exhibit better performance under cyclic operation thanthose without Si dopant.
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