Kinetics of the MgSO4 . 6H2Odehydration reaction for low-temperature thermochemical energy storage applications

Transitioning to renewable energy systems for residential thermal energy supply requires replacing carbon-based technologies. However, renewable energy generation is inherently intermittent, leading to supply–demand mismatches that reduce efficiency. Long-term storage solutions are essential to bridge these gaps and ensure a reliable thermal energy supply. Magnesium sulfate shows promising behavior as a thermochemical energy storage material, but its practical implementation is limited by kinetic constraints. This study models the dehydration reaction of MgSO 4 .6H 2 O up to a temperature of 150 °C, a temperature range compatible with solar thermal collectors, using thermogravimetric analysis at a water vapor pressure of 12 hPa. Through a differential isoconversional method, the reaction from hexahydrate to monohydrate is examined to detect intermediate reaction steps. Moreover, the study identifies an appropriate reaction model and analyzes the dependence of the reaction rate on temperature and pressure. The resulting model shows strong alignment with experimental data, providing valuable insight into the dehydration kinetics of magnesium sulfate under realistic operating conditions and advancing renewable energy storage solutions.