The ERC MetalFuel project explores how metal powders—especially iron—can be used as a clean, circular energy carrier. Over the course of the project, researchers have made major advances in understanding how metal particles burn, how metal flames behave, and how these processes can be scaled up for real world energy applications. The work spans experiments, modelling, and the development of new diagnostic tools and combustion systems.
Understanding How Individual Metal Particles Burn
Researchers developed new experimental setups to observe single metal particles as they ignite and burn. Using advanced optical techniques, they measured particle size, ignition temperature, combustion time, and temperature history. A new single particle burner and an induction based ignition system were created—one of which is now undergoing patenting.
On the modelling side, detailed and simplified combustion models were built to describe the flow, temperature, and chemical reactions around a burning particle. Molecular level simulations helped improve understanding of how iron and oxygen interact, leading to models that match experiments more closely. These findings have been published and form the foundation for larger scale simulations.
Studying Metal Flames in Controlled Conditions
To investigate how metal powders burn collectively, the team developed new burners capable of stabilizing iron flames. A V shaped burner proved especially effective and allowed researchers to measure flame properties such as burning velocity. Optical diagnostics—including particle tracking and holographic interferometry—were developed to visualize flame structure and temperature fields.
In parallel, numerical models were created to describe one dimensional metal flames. These models capture chemical reactions, phase changes, and the influence of different iron oxides on flame temperature and propagation. A quasi 1D model for stretched flames was also developed and validated. Key results have been published.
Advancing to Full 3D Metal Flames
At the largest scale, the project designed and built a 3D iron particle jet burner in collaboration with Delft University. This system enabled the study of stable, optically accessible metal flames. A new hyperspectral pyrometry technique was developed to measure particle temperatures during combustion, and was validated using single particle experiments. Measurements of temperature fields and flame characteristics in turbulent iron air flames have been published.
On the modelling side, the team implemented advanced metal combustion capabilities into the OpenFOAM simulation platform. These tools were used to study laboratory scale and pilot scale burners, including systems up to 100 kW. The simulations revealed the crucial role of radiative heat transfer in metal aerosol combustion, helping resolve discrepancies between earlier models and experiments. These insights will improve future flame models and have been published.
Overall Impact
The Metal Fuels project has:
• Developed new experimental tools and burners for studying metal combustion
• Created advanced models that describe metal particle and flame behaviour
• Improved understanding of how metal powders burn at scales relevant for energy production
