Evaluating the Activity and Stability of CaO-based Sorbents for Post-combustion CO2 Capture in Fixed-bed Reactor Experiments

Carbonate Looping is a post-combustion CO2 capture technology in which CO2 is captured by a CaO-based sorbent. In this work, we report the development, preliminary evaluation and bench-scale testing of synthetic and natural sorbents. After preliminary screening, the most promising materials were studied in a fixed bed reactor under realistic flue gas feed composition. Zr and Al-doped synthetic CaO based sorbents exhibited very high sorption capacity and stability, due to their porous structure that is retained after 20 consecutive carbonation/calcination cycles. The natural sorbents presented inferior results, however their regeneration via hydration seems possible. The presence of steam in the flue gases seems to enhance sorption capacity and stability.