How hot is an iron flame? Using optical/laser diagnostics

Metal powders are a promising candidate for intercontinental and seasonal renewable energy storage. Metal-oxides, with in particular iron, can be chemically reduced to produce metallic powder using a surplus of renewable energy. After storage/transport, this powder can be combusted (similar to coal) to release the stored energy in the form of high-temperature heat. The exact stabilization of such a metal powder flame is still not fully understood, relying on (1) radiative particle-particles, (2) conductive particle-gas, and (3) convective gas-gas heat transfer to continuously ignite newly injected particles. In order to further develop iron powder burners, one would like to measure both the particle and gas temperature in such a flame, in order to validate and improve our numerical combustion models. While measuring the particle temperature is relatively easy by looking at the light emitted (pyrometry), the gas temperature is more difficult. In this project, advanced laser-based methods are developed and employed for this purpose.

This project aims to improve metal powder combustion for clean and safe energy storage and transport. A big challenge when shifting to renewable energy is that of intermittency. Renewable energy might not be produced when and where we need it, requiring efficient energy storage and transport. Metal powders could be a solution. In times of too much wind/solar energy, metal powder can be "energized" (chemically reduced). Then, when the energy is needed, the powder can be burned (rapidly oxidized), releasing heat. This project uses camera's and lasers to study the metal powder flames in order to improve our understanding of this process and help the development of metal powder burners.