Direct solar-driven calcination kinetics for Ca-looping thermochemical energy storage

Ca-looping thermochemical energy storage is considered to be an efficient and low-cost thermal energy storage technology for third-generation concentrated solar thermal power generation. However, the limitation of conventional kinetic studies cannot satisfy the direct solar driven calcination reaction mechanism. Therefore, a direct solar-driven calcination kinetics function of calcium carbonate particles based on multivariate nonlinear regression method is proposed. This scheme driven by full-wavelength solar energy has widely universality and application taking the effects of particle size, porosity, doping composition, temperature and CO₂ concentration into account, which intuitively reflects the essence of photothermal conversion characteristics and reveals the mechanisms of photothermal calcination reactions. The heat storage efficiency of Fe:Mn:Al modified calcium carbonate particles after 20 cycles is 93.03%, the spectral absorption rate is 84.27%. This work provides a new idea for the in-depth study of the decomposition kinetics of solar-driven calcium-based particles.