In future, Trimet will feed around 31,000 megawatt hours of unavoidable waste heat from the process heat of its electrolysis furnaces into the district heating network of Iqony, which supplies customers in Bottrop, Essen, and Gelsenkirchen. This amount covers the calculated demand of more than 5,500 households.
“With this project, Trimet and Iqony are demonstrating what a functioning circular economy looks like in an industrialized nation. Instead of allowing industrial waste heat to go unused, it is being recycled in heating networks,” says Matthias Ohl, Spokesperson for the Management of Iqony Fernwärme. “Waste heat is an important component in the decarbonization of heat supply. Our customers in the Ruhr region are already benefiting from district heating that relies on almost 70 percent climate‑neutral sources – thanks in particular to the use of waste heat. The heating cooperation with Trimet makes our district heating even more future-proof.”
“The fact that we are now heating thousands of homes with waste heat from our plants is a milestone for our company and for the region,” says Dr. Andreas Lützerath, Member of the Executive Board of TrimetAluminium SE. “This clearly shows how innovations are driving forward the green transformation. By making aluminum production more flexible, we are moving closer to our climate protection goals, strengthening the future viability of our production sites, and, together with Iqony, making an important contribution to security of supply.”
Millions invested in climate-friendly heating
The use of industrial waste heat is possible because Trimet has converted its aluminum production to flexible adaptation to the fluctuating power supply from wind and solar plants. Heat exchangers installed specifically for this purpose on the electrolysis furnaces capture the heat from the production process. Four fan stations direct it through a pipe bundle containing water, which is heated to around 130 degrees Celsius. Under high pressure, the water travels through a pipe system to the energy center, where it transfers its heat to the water in the district heating network. To this end, Trimet has installed a 1.6-kilometer-long pipe system on the factory premises, in which 36 cubic meters of water circulate. Iqony has laid a 700-meter-long pipe connection linking the energy center to the connection point outside the factory premises.
In 2023, Trimet and Iqony agreed on a 20-year cooperation agreement on the use of waste heat from aluminum production at the Trimet site in Essen. Work on setting up the infrastructure for converting the production facilities has now been successfully completed. Once trial operation has been completed, the plant will promptly transition to regular operation.
Both companies have invested a high single-digit million euro amount in the project.
