Sorption heat pumps for industrial high-temperature applications: A comprehensive review

• High-temperature sorption heat pumps enable efficient industrial heat decarbonization. • Absorption heat transformers provide heat up to 165 °C, despite lower COP values. • Advanced adsorbents (MOFs, SAPOs, composites) enhance adsorption heat pump performance. • Hybrid sorption–compression systems achieve high COPs and temperature lifts above 150 °C. • Novel working pairs and innovative cycles expand applications in waste heat recovery. High-temperature sorption heat pumps have garnered increasing attention as a critical technology for improving energy efficiency and reducing carbon emissions in industrial processes. This paper provides a comprehensive review of sorption heat pumps, focusing on absorption, adsorption, and hybrid systems for high-temperature applications. The review focuses, with few exceptions, on research published in recent years (especially post-2020) and on systems operating at high temperatures (above 80 °C) and with performances and configurations of particular interest. Absorption heat pumps, while limited by current technologies in achieving temperatures above 100 °C, show potential in innovative configurations, such as hybrid systems and open cycles. Absorption heat transformers, designed for high-temperature industrial applications, are promising due to ongoing advancements in thermodynamic cycles and working pairs, although their coefficient of performance (COP) remains an area of active research. Adsorption heat pumps, particularly in type II configurations, offer significant potential for waste heat recovery and low-temperature heat upgrading, driven by the development of new adsorbent materials. Hybrid sorption heat pumps, which combine absorption or adsorption with vapor compression technologies, stand out for their ability to achieve higher temperature lifts and COPs, making them suitable for diverse industrial applications. The paper highlights the most recent advancement in system design, working fluids, and configurations, while also identifying challenges and future research directions for optimizing performance and expanding the use of these technologies in the industrial sector, particularly in high-temperature applications.