Cyclic CO<SUB align="right">2 capture performance of CaO-based sorbents obtained from various precursors

Abstract

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.