Melting non-ferrous metals in a climate-neutral way is becoming an ever greater challenge. Natural gas-fuelled furnaces are still primarily used for the process. This must change in view of the demand for climate neutrality in all branches of production. That is why the Foundry Institute is researching CO2-free technologies for melting non-ferrous metals, especially aluminium, as well as the heat treatment of steel and cast iron. They are investigating materials, economic efficiency and the effects of a change in technology on existing processes.
Fundamental research into the use of a plasma torch has been completed. Here, a plasma source is used to heat a process gas to a hot gas flow of 1,200 to 1,600 degrees Celsius. This is also the temperature of a conventional natural gas flare. In contrast to natural gas, the heating of such a process gas, which can be air, argon or nitrogen, does not produce any CO2 emissions. The non-combustible gas is heated to a very high temperature and no combustion reaction takes place. If the electrical energy required for the plasma source is generated using green electricity, this technology is CO2-neutral. Major aluminium manufacturers therefore want to replace existing natural gas burners in their furnaces with this CO2-free burner technology from 2025.
Laboratory tests are currently underway for another of the institute's developments, the ultra-high-temperature Thermo Jet. Process gas is also heated here. However, the heat source is a metallic high-melting point heating element that is heated by an induction coil.
Another research project is investigating the melting of aluminium using hydrogen as a fuel gas. Although its availability is still unresolved, the scientists are certain that there will be isolated solutions for this.
Because it is becoming attractive for companies to use green, environmentally friendly hydrogen for smelting. The effects of this on process and melting quality as well as cost-effectiveness are currently being investigated in ongoing research projects and in projects together with companies from industry.