Compressor operated sorption system for high temperature thermochemical energy storage using Mg based hydrides

Thermal energy storage based on sorption technology has been flourishing due to its high storage density, wide operating temperatures, and long-term storage. In this work, an innovative compressor operated sorption thermochemical energy storage (CSTES) system is proposed and investigated for high temperature (>= 250 degrees C) thermal energy storage with a large heat upgradation. The system uses magnesium-based metal hydrides as energy storage material due to their high hydrogen absorption capacity and good reversibility. The proposed CSTES system stores energy in the temperature range between 228 and 587 degrees C with a maximum heat upgradation of 78 degrees C. The highest coefficient of performance and energy storage density of 0.91 and 1991.843 kJ/kg is obtained using Mg-Al-Ti and Mg-Al-Ni alloys, respectively. Variation of compression ratio and heat source temperature on the performance of the CSTES system is studied.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.