Thermoanalytical investigation of some alkaline earth hydroxide hydrates on application as latent heat storage materials

Abstract

Owing to their high specific melting enthalpy and the range of the melting temperatures the alkaline-earth hydroxide hydrates Ba(OH)2·8H2O and Sr(OH)2·8H2O are promising latent heat storage materials.The investigations of the melting and solidification behaviour of Sr(OH)2·8H2O and its mixtures with Ba(OH)2·8H2O, which had been performed by means of DTA and DSC methods in the closed system with a constant gross composition lead to statements on the melting temperature and specific melting enthalpyvs. concentration. Theoretical storage densities of 532 MJ/m3 are obtained for the mixture of Ba(OH)2·8H2O and Sr(OH)2·8H2O (80/20) and a value of 655 MJ/m3 can be achieved for Sr(OH)2·8H2O. The kinetics of rehydration to the octahydrates has a great influence on the storage temperature and storage density.