Combusted iron fuel recovery via hydrogen reduction in the fluidized bed reactor

This work was carried out at RIFT Development B.V. as part of the CIRCL project, which aims to develop circular and carbon-free energy technologies based on iron fuel systems. The project focuses on the modeling and preliminary design of a bubbling fluidized bed reactor for the hydrogen-based reduction of iron oxide powder, a key step in closing the iron fuel cycle and enabling iron reuse as a sustainable energy carrier.
A Python-based phenomenological reactor model was developed to link fluidization behavior, gas-solid interactions, mass transfer, and reaction kinetics un-der realistic operating conditions. Experimentally derived kinetics from thermo-gravimetric analysis (TGA) were combined with reactor-scale hydrodynamics, with particular attention given to the cohesive nature of fine iron oxide particles and its impact on fluidization stability and agglomeration at elevated temperatures.
Reactor performance was evaluated using practical key performance indica-tors, namely hydrogen conversion per pass and the time required to reach a tar-get degree of reduction. The resulting model provides a structured framework for assessing reactor behavior, supporting design decisions and future scale-up. Overall, this work contributes to the development of hydrogen-based iron reduction technologies and supports the broader goals of the CIRCL project in advancing circular and low-carbon energy systems.