Study on Binary Hydrated Salt Composite Zeolite as Materials for Improving Thermochemical Energy Storage Performance

Thermochemical energy storage is a promising approach in thermal energy storage because of its advantages in high heat storage density, low heat loss and long period stability. The hydrated salt is a commonly used material in low temperature heat storage. In this study, the preparation of MgCl2 and CaCl2 binary hydrated salt composite zeolite is proposed. It’s found that the optimum concentration is 15wt% and the better mass ratio of MgCl2 to CaCl2 is 1:1.5, which could lead to better thermal performance. The metal mesh net packed method is adopted for further improvement. A thermochemical energy storage experiment is conducted to compare the effects of the composite material. The results show that the binary hydrated salt composite zeolite can increase the temperature rise up to 45.8 °C at the air velocity of 0.18 m/s. It can achieve the highest energy storage density of 719 kJ/kg and thermal efficiency of 41.9% at the air velocity of 0.32 m/s. Also, the combination with metal mesh packed nets can further improve the temperature rise peak, energy storage density and the thermal efficiency to 52.7 °C, 918 kJ/kg and 46.1%, respectively. This study provides references for multicomponent composite material preparation and thermochemical reactor improvement