Cyclic CO2 capture performance of CaO-based sorbents obtained from various precursors

The effects of pore morphology and crystal structure of CaO-based sorbents derived from various precursors were investigated to elucidate the property dependence of CaO-based sorbent performance for cyclic CO2 capture. The results indicate that CO2 capture capacity of the first carbonate looping cycle is dependent on the specific surface area of CaO-based sorbents. The carbonation conversions of the initial calcined sorbent are restricted from 29% to 83% due to the limitations in the small pores with diameter range from 20 to 70 nm. The initial calcination of CaO-based sorbents obtained from the inorganic precursors leaves an 'imprint' in the following carbonation/calcination cycles, which leads to greater decay rate of carbonate conversion than the organic precursors. Increase of carbonate conversion with cycle number is found for CaO-based sorbent obtained from calcium L-lactate hydrate and this reactivation phenomenon is probably due to its special crystal structure.