Enhanced Thermochemical Energy Storage Properties of SiC-doped Calcium-Based Material with Steam Addition During Heat Charging Process

Thermochemical energy storage based on the reversible carbonation/calcination reaction of CaCO3/CaO is emerging as a promising technology for energy storage in concentrating solar power systems. However, the inherent weak solar absorption capacity of natural calcium-based materials necessitates a substantial enhancement in their solar absorption capability. In this study, dark SiC particles of different sizes were introduced into CaO-based composite particles supplemented with cement and microcrystalline cellulose. The aim was to explore the influence of SiC components on the solar absorptivity, energy storage capacity, thermal conductivity, and mechanical properties of CaO-based particles. The results indicate that doping 10 wt% of SiC with a size of 25 mu m in CaO-based particles demonstrated optimal results, corresponding to a 20.3 % increase in the average optical absorption and a 2.86-fold improvement in the thermal conductivity compared to the undoped particles. Furthermore, introducing steam during the decomposition of SiC-doped CaO-based particles significantly enhanced the mechanical properties. The breaking force of SiC-doped CaO-based pellets after 50 runs with 10 vol % steam addition was 1.39 times higher than that of the identical particles without steam treatment.