Abstract:
The two-step solar-thermochemical cycle process for water splitting is a promising technology for hydrogen generation with very high theoretical efficiencies. This study investigates the operational behavior of a prototype solar reactor with thermal power of 250 kW. A multi-physical reactor model is used for analyzing the dynamical process behavior of the reactor’s porous metal oxide absorber. A new process diagram is introduced, which captures transient and stationary cycle conditions for temperature swing operation.
The focus of this work is on the influence of fluid properties and related operational parameters. Besides mass flows and purity of the fluids, the time between cyclic temperature variation and corresponding fluid switchover is investigated thoroughly, which has not been done so far. It is found out that by adapting fluid switching times the efficiency can be increased by around 5%, while higher purge gas purity and enlarged steam flow may even double the plant efficiency.
Jörg Lampe, Johann Krause, Steffen Menz, Process behavior analysis of a fixed-bed solar reactor for hydrogen generation via two-step thermochemical redox cycling, International Journal of Hydrogen Energy, Volume 144, 2025, Pages 1328-1342, ISSN 0360-3199, https://doi.org/10.1016/j.ijhydene.2025.03.114
