Iron powder to store energy?

Storing energy in metals and burning them to release it when necessary is a method already applied in aerospace technology.

Our goal was to understand what exactly happens in the micro and nanoscale during the reduction and combustion of iron. And how the evolution of the microstructure affects the efficiency of the process.

Furthermore, we wanted to find a way to make this process circular without any loss of energy or material.

This was stated by scientists Max-Planck-Institut für Eisenforschung and Eindhoven University of Technology, who took their cue from the aerospace world to study the processes underlying iron combustion and their use in energy storage devices.

The process of accumulating energy in the iron powder requires the reduction of iron oxide to iron. The energy is released with the reverse process, namely the oxidation of iron into iron oxide.

In research, the group of scientists focused on the characterization of powders after reduction and oxidation to evaluate their purity, porosity and morphology.

The microstructure of these particles is, in fact, a determining factor for overall efficiency. They also studied the thermodynamics of the process to understand if a completely circular system could be obtained, without having to add new materials or energy to each new cycle.

The study showed that iron dust is able to accumulate energy, but new studies will have to be carried out to improve its overall circularity, since the size of some burnt particles is reduced compared to their original size.

Think of iron powder as a charged battery. When it is burned, energy is obtained from it and what is left is a dead battery in the form of rust. By making iron dust from the rust again, it recharges the battery. And you can do it again and again.

The focus on iron as a fuel will grow rapidly.

An industrial incinerator is under construction. It has a power of up to 1 megawatt. Everyone sees potential on a larger scale.

The Earth has iron ore in abundance. But does this also apply to iron powder?

No. There are currently about ten suppliers all over the world. With the current supply, we could now convert ten coal-fired power plants and supply them with iron powder. But if the market demand increases, then the stock will be there.

The big plus is that you only need to make that powder once. So you can reuse it constantly. Iron remains iron. “