Natural Refrigerant, High Temperature Heat Pump

Thermal energy needs in industry are a significant challenge for decarbonization efforts. Heat represents two-thirds of all energy demand in the industrial sector, and one-fifth of energy demand across the globe. However, only 10 percent of this demand is met using renewable energy. There is a significant opportunity to decarbonize the industrial sector by shifting heat production away from carbon-intensive fossil fuels to clean sources such as electrification where low- or zero-carbon electricity is used. This project will address this challenge through the development of a High Temperature Heat Pump (HTHP). The proposed HTHP will efficiently transform waste heat, ~100°C, to useful process heat, 200°C, using electricity. The same concept is capable of producing process heat up to 800°C. The development of the HTHP will require several technical milestones to be achieved. This includes performing comprehensive thermodynamic cycle analysis and building a novel compressor prototype based on an ionic liquid piston concept using carbon dioxide (CO2) as a natural refrigerant, R744. Air to supercritical CO2 heat exchangers (HXs) will also be designed based on a patented design that offers superior thermal and pressure drop performance to state-of the-art HXs and can be mass produced. The proposed natural refrigerant, high temperature heat pump can replace carbon-based fuels, cost effectively, with sustainable electrification, to generate Quads of process heat, using greater than 1.2 Quads of waste heat, unrecoverable by U.S. industries such as the paper and pulp, chemical, food, and metal industries. By producing high temperature heat from waste heat and carbon-free renewable electricity, USA economic and energy security will be enhanced by reducing energy imports and improving energy efficiency in the industrial sector. The project team has deep experience with these technologies. Thar was the first to establish a commercial scale, direct exchange, geothermal, heating and cooling, heat pump system using CO2. Thar also has unique experience in developing pumps, expanders, and heat exchangers that operate at extreme temperatures and pressures, for the supercritical CO2 Brayton power cycle systems. The University of Maryland Advanced Heat Exchangers and Process Intensification (AHXPI) laboratory will assist with the development of HXs. AHXPI is internationally recognized for its expertise in developing HX solutions for industrial, commercial, aerospace, and electronics applications.