Development of porous solid reactant for thermal-energy storage and temperature upgrade using carbonation/decarbonation reaction

Cyclic reaction performances of solid reactants for a CaO-CO2 chemical heat -pump designed for upgrading and storing high-temperature thermal energy we re studied. Solid reactants composed of CaO as the reactant and CaTiO3 as t he inert framework were prepared using the conventional powder method or th e metal alkoxide method. Upon experiments of cyclic operation between CaO c arbonation and CaCO3 decarbonation at 1023K, the reaction reversibility of the solid reactants with the inert CaTiO3 framework was steady, whereas tha t of the solid reactant without the inert framework decreased with sinterin g of the solid particles during cyclic operation. Reaction rates for the fi rst carbonation and the decarbonation of solid reactant prepared using the alkoxide method were about 1.8 and 2.4 times faster, respectively, than for those prepared by the powder method due to the smaller average diameter of reactant particles derived from the alkoxide method. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.