(146d) Reactivation of Calcium-Based CO2 Sorbents through Hydration – A Mechanism Study

The increasing concern over global warming has promoted numerous studies on CO2 capture in fossil fuel based power generation systems. The concept of calcination and carbonation looping, which uses a calcium based CO2 sorbents, is a promising technique for both post combustion and pre combustion CO2 capture. Although theoretically more efficient than conventional CO2 capture techniques, the actual cost and energy saving using the carbonation-calcination looping cycle is significantly affected by the recyclability of the CaO sorbents as well as the effectiveness of the sorbent reactivation strategies. Various literature studies have identified hydration as an effective reactivation strategy for partially deactivated sorbents.

An ideal strategy would, therefore, be able to effectively recover sorbents from the severe sintering at high temperature. This paper studies the sorbent reactivation mechanism through hydration. Sorbents are reactivated through hydration by steam or water. The sorbent reactivity and morphology are studied. It is observed that the CaO sorbents are able to maintain high reactivity for multiple carbonation-calcination reaction cycles. A reactivation mechanism model is proposed to explain the effects of hydration.