Metals as alternative to fossil fuels

Published 28 October 2022

Iron particles burning. Picture. — Iron particles burning. Looks like fireworks since metals are what is used in fireworks to create different colors.

Can metals really burn? Well yes, and you have most definitely seen them burn since metals often are used in fireworks to get different colors. These colorful flames have the potential to be used as alternative to gasoline and other fossil fuels in a clean cycle for storing energy. This cycle will start with a pure metal powder such as aluminium or iron. Then, the powder is burned where energy is released and used and the metal is finally found in an oxidized format. This oxidized metal is then reduced to extract new metal powder while releasing oxygen. If this reduction is performed using fossil free energy, the clean cycle is complete.

One of the main problems with energy is transport. We often have access to a lot of energy such as light from the sun in the Sahara or geothermal energy in Iceland. But most people do not live at these places and where the people are is where the energy is needed. Therefore efficient transport of energy in the form of fuel is important and to make this efficient we want to have as much energy as possible per kilogram and volume fuel. Metals are here a great alternative since they are one of the options with high energy density when comparing different fuels.

We have a research project that focuses on finding and understanding the characteristics of metal combustion to make them useful in large scale facilities. Currently our work is focused on aluminium since it has the possibility to be burned in water vapor. This special combustion will result in heat and hydrogen where the hydrogen can be further used in cars as fuel. This means that we indirectly can store hydrogen in aluminium which is much safer since hydrogen gas has a tendency to blow stuff up.

In our research we use lasers to measure different important aspects of the metal combustion with the goal of understanding how it can contribute as a fossil free fuel in the future.