Isopropanol-Acetone-Hydrogen chemical heat pumps for improved heat recovery from geothermal resources, A case study in China

This study focuses on geothermal energy utilization through multi-objective optimization of IsopropanolAcetone-Hydrogen chemical heat pump (IAH-CHP). In this paper, IAH-CHP coupled with medium-low temperature geothermal heat source simulation was constructed. China, the world's largest carbon emitter, was used as a case study to highlight environmental benefits. Comparative analysis was conducted between carbon emissions and investment of chemical heat pumps with other common heating equipment indifferent buildings. The results show IAH-CHP system has higher initial investment costs, however, their CO2 emissions are significantly lower. The results of multi-objective analysis demonstrate the system can operate under a Pareto (multi-objective) optimal scheme. Under this plan, the levelized cost of heat (LCOH) is only 0.12 USD/kJ, and the carbon emissions are as low as 4.97 tons/year with a coefficient of performance (COP) of 7.4. Compared with a single-objective optimal solution, 8.12 tons of carbon emissions and LCOH of 0.15 USD/kJ could be achieved. Applying IAH-CHP system to China to replace original coal-fired heating solution can achieve annual carbon emission reduction of more than 5 million tons in areas with medium and low temperature heat sources.