Hydrogen based heat pumps using metal hydrides: Synergies between H2 infrastructure and industrial heat supply

Kurzfassung

Hydrogen is gaining widespread recognition both as a valuable reactive molecule in chemical applications and as a cleaner, more sustainable substitute for traditional industrial heat sources. In many hydrogen-powered industrial processes, the supply pressure is much higher than the required end-use pressure, presenting an opportunity to recover excess energy. One promising approach is the incorporation of metal hydrides (MH) into hydrogen infrastructure to exploit the high-pressure hydrogen stream for upgrading waste heat across various temperature levels. This study presents the concept and operation of a quasi-continuous hydrogen heat pump (H2HP) based on MH for hydrogen infrastructure, evaluating its performance in different scenarios for both open and closed industrial processes. Emphasis is placed on selecting appropriate MH materials to match specific waste-heat temperature levels, outlining key thermodynamic and practical criteria. A comprehensive thermodynamic assessment quantifies the fuel savings (∼10-20%) and additional heat supply (∼10-30%) of the H2HP in open-loop industrial process-heating applications, using two different alloys from low- and high-temperature MH classes. To address real-world deployment, the study further examines scaling behaviour, integration challenges, and the economic feasibility of the H2HPs within hydrogen infrastructure.