Safe seasonal energy and hydrogen storage in a 1 : 10 single-household-sized pilot reactor based on the steam-iron process

• Published in: Sustainable energy & fuels 2023-12, Vol.8 (1), p.125-132
• Main Authors: Heiniger, Samuel P, Fan, Zhiyuan, Lustenberger, Urs B, Stark, Wendelin J
• Format: Article
• Language: English
• Subjects: Chemical analysis; Energy sources; Energy storage; Hydrogen reduction; Hydrogen storage; Iron oxides; Reactors
• ISSN: 2398-4902; 2398-4902
• DOI: 10.1039/d3se01228j

Our society is gradually moving from traditional energy sources to renewables. Due to the temporal mismatch between the production and demand of renewables, seasonal energy storage is proposed as a way to bridge the gap and ensure reliable power supply throughout the year. In this article, we demonstrate a seasonal energy storage process based on the redox pair iron/iron oxide, where energy is stored in the form of fine iron powder produced on-site by reducing iron oxide with electrolytic hydrogen, and released by oxidizing iron with steam. We prove its feasibility at a technically relevant scale, in a 1 : 10 scaled-down pilot reactor representing the electricity need of a typical European household. The operating data of the reactor, together with physico-chemical analysis of the iron/iron oxide during this process, and calculated estimation of its investment cost, provide a solid foundation for its future application in the field of energy storage. The seasonal storage of hydrogen and energy using iron as a storage medium is demonstrated at a technically-relevant level using a 0.21 m 3 pilot reactor.