Preparation of morph-genetic aluminum-doped calcium oxide templated from cotton and the calcium looping performance for energy storage in the presence of steam

Abstract

Calcium looping (CaL), which can be combined with concentrated solar power (CSP) plants, is considered a promising technology for energy storage. To overcome the deactivation of calcium based materials with increasing cycles, a novel morph-genetic aluminum doped calcium oxide was prepared by a biomass template method using limestone, aluminum nitrate and cotton as raw materials. The effects of preparation parameters and heat storage conditions (especially in presence of steam) on the energy storage performance were studied. The results showed that the hollow tubular structure of the biomass template was preserved in the synthesized material and stabilized by the support of Ca12Al14O33. The presence of the hollow microtubular structure resulted in an increased pore volume of the synthesized materials and a change of the pore distribution, promoting the diffusion of CO2. This phenomenon also explained the superior performance of the synthesized material in terms of the apparent kinetic properties and resistance to sintering. The optimal synthesized material had a high energy storage density and carbonation fraction, which were more than three times those of limestone. The presence of steam during calcination served to reduce the calcination temperature and mitigate the sintering effect of CaO. An optimization route combining solar steam system and CaL-CSP system was proposed based on the positive effect of steam, which was promising for high-efficiency energy storage.