Cyclic performance of CaCO3@mSiO2 for CO2 capture in a calcium looping cycle

Abstract

A simple and cost-effective one-pot synthesis route to directly prepare CaCO₃@mesoporous silica in a core–shell structure (denoted as CaCO₃@mSiO₂) as a high-performance CO₂ sorbent has been developed. The (CaCO₃@mSiO₂)-based sorbents with and without pelletization showed superior CO₂ adsorption performance compared to a CaCO₃-based sorbent. The carbonation conversion of the (CaCO₃@mSiO₂)-based sorbents as well as the retention of the carbonation conversion has been significantly improved by coating the mesoporous silica onto the CaCO₃-based sorbents. The best adsorption performance is obtained by using the (CaCO₃@5.6 wt% mSiO₂)-based sorbent. The improved carbonation conversion retention of the (CaCO₃@5.6 wt% mSiO₂)-based pellet sorbent is around 25% after 50 cycles of decarbonation/carbonation, which is higher than that of the CaCO₃-based sorbent (13%). The resultant (CaCO₃@mSiO₂)-based sorbent has high resistance toward carbonation/decarbonation reaction.