Due to intermittency of primary energy sources (like solar and wind), a successful energy transition necessities efficient and cost-competitive energy carriers. Iron powder is a promising candidate, as it is carbon free, recyclable (thus renewable), easy to transport, and has high energy density and good specific energy.
Cyclic oxidation and reduction of iron powder stands out for seasonal storage and long-distance transport of renewable energy. When iron powder is burned, it releases energy, and the iron powder is transformed into solid iron oxide. Iron oxide is turned back into iron powder again by reducing it with clean energy resources (energy storage). We focus on production and regeneration of iron powder, which is the key to make Iron Power a renewable circular energy system.
Hydrogen based Direct Reduced Iron (DRI)
Hydrogen based DRI use hydrogen gas as the reducing agent to react with the oxygen in the iron oxide, forming water vapor as a byproduct. Due to the endothermicity of the reactions, H2-DRI is favoured at high temperatures (>600 掳C). Large-scale deployment of this technology still faces many challenges. In this area, we work on the following topics via both experiments and Computational Fluid Dynamics (CFD) modelling:
- Determining the chemical reaction kinetics
- Understanding and controlling the fine particle sintering
- Optimizing and scaling up H2-DRI in fluidized beds
Low-temperature electrolysis (LTE) of iron oxides
We are developing a novel low-temperature electrolysis method for iron (powder) production. Micron-sized iron oxide/ore powder is added as suspension in a strong alkaline aqueous electrolyte in an electrochemical cell operated at low temperature of ~110 掳C. By applying electricity to the cell, metallic iron is deposited at surface of the cathode, while Oxygen is produced at the anode, without direct CO2 emission. By tuning the operation conditions, deposits present different morphologies, which can be directly harvested as iron sheets or iron powder. For development of this novel technology, we work on the following topics:
- Understanding the mechanisms and kinetics of oxide-to-iron transformation
- Unveiling the mechanisms of formation and microstructure evolution of iron dendrites
- Designing novel process for continuous production of electrolytic iron powder
- Developing numerical models for the underlying Multiphase Multiphysics
