Development of a hydrocarbon cascade high-temperature heat pump for industrial decarbonization
High-temperature heat pumps (HTHPs), capable of supplying heat above 100 °C, are emerging as a crucial technology for decarbonizing industrial heat by efficiently utilizing waste heat and clean electricity. These systems are increasingly recognized in climate policy roadmaps, with significant targets set for their deployment in the coming decades. HTHPs can be integrated at either the process or utility level, each offering trade-offs between efficiency, complexity, and ease of implementation. Despite clear environmental and economic benefits, market penetration of HTHPs at temperatures exceeding 100 °C remains limited due to current gaps in compressor technology among others. Addressing this, the presented research describes the development and laboratory testing of a cascade HTHP system using isobutane and isopentane as refrigerants, designed for industrial applications requiring heat up to 170 °C. The system, with a heating capacity of approximately 500 kW and a coefficient of performance around 2.5, demonstrates the potential for high efficiency and operational flexibility through advanced integration and control strategies. Testing revealed necessary optimizations to control systems and heat exchanger configuration, ensuring stable, effective operation under varying laboratory conditions. Temperatures of up to 168°C have been demonstrated. The system will be transferred to an industrial site for real-world demonstration. This work underscores the promise of HTHPs for industrial energy transition, while highlighting ongoing challenges in system integration, control, and real-world deployment.