Evaluation of calcium looping CO2 capture and thermochemical energy storage performances of different stabilizers promoted CaO-based composites derived from solid wastes

Calcium looping is considered as an important high-temperature cyclic CO2 capture and concentrated solar energy storage technology. However, the dramatic inactivation of CaO over multiple carbonation-calcination cycles has seriously restricted their practical applications. In this study, a series of metal oxide (i.e. TiO2, MgO, Al2O3 and ZrO2)-stabilized CaO-based materials with high cyclic stability derived from carbide slag were synthesized via a facile and cost-effective approach for simultaneously enhanced CO2 capture and thermochemical energy storage (TCES). The results suggest that CCS-H-TiO2 exhibits high initial CO2 uptake of 0.41 g CO2 /g sorbent , superior cyclic stability with an average attenuation of 1.71 %/cycle and remarkably stable energy storage density. CCS-H-Al2O3 shows the best stability with lowest attenuation rate of 9.6 %. Except for CCS-HMgO, the stabilizers reacted with active calcium to form new phases and used as physical "barrier" and high-TT skeleton to offset the sintering stress, retain the microporous structures, hinder the excessive agglomeration and alleviate sintering.