Key Words:HEAT-STORAGE; CALCIUM HYDROXIDE; SYSTEM; CAO/CA(OH)(2); PERFORMANCE; COMPOSITES; CA(OH)(2); WASTE; BED
Abstract:Calcium hydroxide (Ca(OH)2) stands as one of the most promising thermochemical energy storage materials (TESM) for concentrated solar power (CSP). However, it suffers from the shortcomings of low solar absorptivity, slow dehydration reaction rates, and poor cyclic stability. In this study, a Ca(OH)2-based TESM capable of direct harvesting of solar energy was developed with oyster shells as a calcium source and copper chromium black as a solar absorber. For the first time, we investigated the dehydration chemical reaction (heat storage) of the Ca (OH)2-based TESM under concentrated solar irradiation. The influence of copper chromium black content on the photothermal conversion, dehydration rate, and energy density of the Ca(OH)2-based TESM were explored. The sample with 10 wt% copper chromium black exhibits a solar absorptivity of 75.65 %, which is 5.9 times that of pure oyster shell. A conversion ratio of 95 % and an energy density of 1589 J/g were achieved under solar radiation for 160 s at the intensity of 34.2 kW/m2. The conversion ratio maintains at 85 % and the energy density at 1302 J/g after 100 cycles of dehydration/hydration, demonstrating excellent cyclic stability. The findings of this study offer guidance for the design, preparation, and industrial application of solar-driven Ca(OH)2-based TESM.
Volume:84
Issue:-
Translation or Not:no