The effect of BeO on heat transfer and durability of nano-CaO-based CO2 adsorbents

Abstract

The solution of decreasing the decomposition temperature of CaCO₃ and the development of the durability of the CaO-based CO₂ adsorbent are the key issues in reducing the energy consumption and cost of CO₂ capture in calcium looping technology. In this work, BeO with high thermal conductivity was chosen as a dopant of the adsorbent to increase the thermal conductivity properties and decomposition properties of CaCO₃. The endothermic rate of the nano-CaO-BeO/Al₂O₃ adsorbent with 15.6 wt% BeO dopant increased by 12.3% compared with that of the nano-CaO/Al₂O₃ adsorbent at 720 °C, leading to an increase of 10.1% of CaCO₃ decomposition rate. The enhancement of the decomposition rate of the nano-CaO-BeO/Al₂O₃ adsorbent was significant to lower the regeneration temperature by 50 °C compared with that of the nano-CaO/Al₂O₃ adsorbent under calcium looping conditions, which made the total average deactivation rate decrease by 21.0% and made the total residual stable carbonation conversion increase by 27.0% in infinite calcium looping cycles. Strengthening the heat transfer inside the adsorbent material can effectively decrease the regeneration temperature, so as to improve the sorption durability.