CaO/CaCO3 thermochemical heat storage performance of CaO-based micrometre-sized tubular composite. (15th October 2020) - Sun, Hao
Highlights: CaO-based micrometre-sized tubular composite is yielded by template for heat storage. Energy density of the composite is up to 2924 kJ/kg after 30 heat storage cycles. The composite maintains porous and hollow structure during multiple cycles. CaO-based micrometre-sized tubular composite has high sintering resistance. The micrometre-sized tubular composite has large surface area and pore volume. Abstract: To ameliorate the decay in heat storage performance of CaO-based materials with the number of CaO/CaCO3 heat storage cycles, in this study, we used the template method to fabricate CaO-based micrometre-sized tubular composites containing CaO, Al2 O3, and CeO2 and analysed their performance at a high carbonation pressure. It was found that these composites, when doped with 2.5 wt% Al2 O3 and 1 wt% CeO2, exhibited an excellent heat storage performance. The heat storage capacity of the novel composites decreased by only 2% over 30 heat storage cycles, and their effective conversion and energy density were as high as 0.92 and 2924 kJ/kg, respectively, after 30 cycles. Morphological analysis of these composites indicated the presence of porous microtubules with diameters in the range of 5–10 μm. Ca12 Al14 O33 and CeO2 grains in the microtube walls effectively stabilised the structure during cyclic heat storage. Therefore, the novel composites have promising applications in CaO/CaCO3 -based heat storage processes.