Thermochemical heat storage performances of fluidized black CaCO3 pellets under direct concentrated solar irradiation

Evaluation of Thermochemical Energy Storage Performance of Fe-/Mn-Doped, Zr-Stabilized, CaO-Based Composites under Different Thermal Energy Storage Modes

“…The CaO-based composites need to continuously circulate in the fluidized bed-based CaL system aiming to achieve efficient and stable solar energy storage/release. The powdered CaO-based composites are prone to rapid elutriation and a sharp pressure drop . To improve the practicability of the CaO-based composites, a granulation treatment was conducted for Ca100/Zr6.7–Mn6–Fe12.…”

“…In addition, the commonly used surficial-type solar receiver adopts the surface-heating mode, which encounters a severe loss of solar–thermal conversion efficiency due to multiple energy transfer . In contrast, the volumetric-type solar receiver can achieve direct contact between the solar radiation photons and calcium-based composites, subsequently eliminating the thermal resistance and improving the solar–thermal conversion efficiency . The improved optical absorption capability toward solar radiation is required for CaO-based composites under direct solar absorption mode, which is also conducive to reaching the required decomposition temperature for CaO-based composites to drive the endothermic reaction presented in eq .…”

“…The doping of optical absorption-enhanced elements (i.e., Fe, Mn, Cu, Co, and Cr) − is commonly employed to increase the solar absorption capability of CaO-based composites, as listed in Table S1. Teng et al found that ion doping of optical absorption-enhanced elements was superior to particle-doping mode in enhancing the solar absorption capability of CaO-based composites.…”

“…32 In contrast, the volumetric-type solar receiver can achieve direct contact between the solar radiation photons and calcium-based composites, subsequently eliminating the thermal resistance and improving the solar−thermal conversion efficiency. 33 The improved optical absorption capability toward solar radiation is required for CaO-based composites under direct solar absorption mode, which is also conducive to reaching the required decomposition temperature for CaO-based composites to drive the endothermic reaction presented in eq 1. Therefore, the optical absorption capability is another key index for the CaCO 3 /CaO composites used in the CaL in the volumetric-type solar receiver.…”

Enhanced Thermochemical Energy Storage Stability of CaO-Based Composite Pellets Incorporated with a Zr-Based Stabilizer

“…Therefore, an extra modification step of pore-forming needs to be conducted during the extrusion–spheronization process to regain the porous structure for the CaO-based composite pellet. ,, It is necessary to find an alternative strategy of extrusion–spheronization to achieve the balance between the mechanical strength and porous microstructures of the CaO-based composite pellet. Graphite casting is a low-energy consumption granulation method, which has been successfully adopted to prepare Li 4 SiO 4 , and CaO pellets for CO 2 capture. The granulation principle of graphite casting is mainly based on the hydrophobicity of graphite powder and the surface tension of precursor droplets, which causes limited destruction of the porous structure.…”