CO2 thermochemical sorption battery driven by low temperature heat source for plus energy building application

In recent, plus energy building has been extensively paid attention to reduce the grid energy consumption of buildings. The plus energy building is defined as the building that generates more renewable energy than its required energy load. For this purpose, an effective thermal energy storage system is essential to utilize renewable energy produced in buildings. Herein, a thermochemical sorption battery with high energy storage density utilizing CO2 and monoethanolamine (MEA) as working fluids is developed. The catalyst Al2O3/HZSM-5 is synthesized to improve the energy storage density of thermochemical sorption battery under charging conditions with low temperature heat source. As the coefficient of performance (COP) and energy storage density of CO2-MEA thermochemical sorption battery are compared in terms of heat source temperature and mass ratios of catalyst composite, the optimum temperature of the thermochemical sorption battery is selected as 100 °C. The utilization of the optimized material AH11 in the CO2-MEA the thermochemical sorption battery resulted in a noteworthy advancement, boasting a 31.5 % increase in the COP and an impressive 57.5 % enhancement in energy storage density at the modest charging temperature of 100 °C. The enhancement mechanism is related with the Bronsted acid sites and the basicity of the catalyst. It is confirmed that the Lewis acid sites present in the catalyst are converted to Bronsted acid sites during the catalyst synthesis process, which enhances the performance of the catalyst. When the CO2-MEA thermochemical sorption battery with AH11 is applied to the buildings, it leads to 58.1 %, 73.1 % and 79.0 % reduction in the total energy consumption for medium-sized family house, hotel and hospital, respectively.