Reactive MP-PIC simulation of hydrogen-based iron oxide reduction in a fluidized bed reactor

Hydrogen-based direct reduction of iron has the potential to drastically reduce the carbon dioxide emissions of steelmaking. However, widespread adoption of fluidized bed reactors is limited due to operational instabilities. This study presents a numerical model simulating iron-oxide reduction within fluidized bed reactors, with validation against literature confirming the model’s accuracy in predicting pressure drops and hydrodynamic trends. Further, we explore how varying process conditions, such as temperature and reduction degree, influence reactor performance and stability in real-world conditions. Key findings demonstrate that elevated process temperatures and higher reduction degrees correlated with increased particle bed instabilities and a greater risk of channelling. Another notable observation is that the potential for reoxidation reaches its maximum at mid-reduction, likely contributing to the decline in reaction rate. These insights enhance our understanding of the complex reduction process, offering potential productivity improvements for hydrogen-gas-based fluidized bed reactors. • We simulate hydrogen-based direct reduction of iron within a fluidized bed reactor. • Gain insights into difficult-to-observe conditions within an active reactor vessel. • Novel streamlined implementation of the reactive model within the MP-PIC framework. • Discuss impacts of varying process conditions on reactor performance and stability.