Performance investigation of SrCl2/Al2O3 composite for thermal energy storage: Numerical modelling and experimental study

Thermochemical adsorption energy storage (TCES) offers a compelling strategy to bridge the gap between intermittent renewable energy supply and continuous thermal demand, owing to its high energy density, operational safety, and long-term storage potential. Building on our previous demonstration of the SrCl 2 /Al 2 O 3 composite synthesized via vacuum impregnation with favourable material-level performance, to advance its application, this study further investigates and enhances its performance at the reactor scale through a combined experimental and numerical approach in this study. The key thermophysical properties and kinetic parameters of hydrated salt composite were determined, and the Coats-Redfern (C-R) integral method f( α )=(1- α ) 2 was identified as the most suitable mechanism function for its dehydration process. Subsequently, a numerical model of the composite-filled thermochemical reactor was developed and validated against experimental results. Finally, sensitivity analyses revealed that reaction time is most sensitive to inlet air flow rate, while thermal efficiency was most sensitive to inlet air temperature. Furthermore, the reactor achieved a thermal efficiency of 82.55%, comparable to values reported in the literature. In summary, these findings establish SrCl 2 /Al 2 O 3 composites as a promising candidate for thermal energy storage applications and provide practical insights for the design and operation of high performance thermochemical thermal energy storage reactors.