Improvement of durability of nano-CaO-based adsorbents by chemical looping in situ dynamic pore compensation

In situ pore forming achieved by vapor releasing of chemical looping reaction for dynamic compensation of lost pore volume was proposed to improve the durability of the nano-CaO-based adsorbent in calcium looping process. The effect of contents (12–34 wt.%) and kinds of the pore forming agents (MnO 2 , Fe 2 O 3 , Co 2 O 3 , NiO and CuO) on the dynamic pore compensation effect and sorption performance including sorption capacity and durability of the adsorbent was investigated. The results showed that high pore forming capacity could be achieved by high doping content and oxygen mass fraction of agent. Good anti-sintering ability of agent could leads to a prominent pore forming stability. The final dynamic pore compensation effect was controlled by both pore forming capacity and stability. Compared with the nano-CaO/Al 2 O 3 adsorbent, the best dynamic pore compensation effect for the nano-CaO-NiO/Al 2 O 3 adsorbent was achieved with doping NiO content of 21 wt.%, which could increase pore volume by 67.3% after 3 CaL cycles. The total average deactivation rate of the nano-CaO-NiO/Al 2 O 3 adsorbent was reduced by 48%, which meant that in situ dynamic pore compensation could significantly improve the cyclic durability of adsorbents. Graphical abstract