Hydration reaction kinetics of SrCl2 and SrCl2-cement composite material for thermochemical energy storage

Abstract

Thermochemical energy storage using salt hydrates is a promising method to store low-grade heat and resolve the mismatch between supply and demand of renewable energy sources. In this study, the hydration reaction kinetics of the salt, SrCl 2 and its composite with cement were investigated experimentally as a potential heat storage material. Characterization of the materials were performed in a humidity chamber under various water vapour partial pressures and temperatures. Firstly, a reaction kinetics model was developed for the hydration of SrCl 2 to SrCl 2 ·6H 2 O. Secondly, a shrinking-core model was developed to describe the behaviour of two sizes of a spherical SrCl 2 -cement composite. The shrinking-core model for salt in a cement porous host matrix combines chemical reaction and moisture diffusion to define the overall reaction rate. These kinetic models can be used to predict the performance of a packed bed thermochemical energy storage system. • SrCl 2 hydration reaction rates under various water vapour partial pressures and temperatures were investigated. • Reaction kinetics for hydration of SrCl 2 was developed. • A shrinking core model of salt held in a porous matrix for thermochemical energy storage was developed.