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

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.