Different Sorbents in Calcium Looping Cycle for CO₂ Capture

Cyclic CO₂ capture using commercial pure micro CaCO₃ and nano CaCO₃ is investigated in this paper which focuses on the different characteristics two different sorbents during high temperature reactions. The results indicate that the nano CaCO₃ sorbent has higher carbonation conversions and carbonation rates than the micro CaCO₃ sorbent in the cyclic reactions. Furthermore, nano sorbent can retain its fast carbonation rates at the beginning dozens of seconds during each cycle. In contrast, the carbonation rates of micro sorbent diminish with the increase of cycle number. But, unfortunately, CaO derived from nano CaCO₃ sorbent sinter much easily. Its grains, which are composed of numerous spherical nanocrystallites, experience dramatic morphological changes during high temperature reactions.