Waste heat from aluminum smelter TRIMET to benefit Iqony’s district heating supply


TRIMET Aluminium SE and Iqony Fernwärme GmbH have concluded a cooperation agreement on the use of waste heat from aluminum production at TRIMET’s Essen site. From January 2025 onwards, TRIMET’s aluminum smelting plant will feed around 31,000 megawatt hours (MWh) per year into Iqony’s district heating network. With this cooperative venture, the two partners are strengthening their commitment to shaping the transformation of the heating sector. The cooperation will further improve the carbon footprint of the already climate-friendly district heating supply in Essen, Bottrop and Gelsenkirchen.

The cooperation project between TRIMET and Iqony Fernwärme is initially scheduled to run for 20 years, with TRIMET making the industrial waste heat from its aluminum plant available to the district heating network. Aluminum is produced using an electrochemical process. This fused-salt electrolysis process produces liquid aluminum at a temperature of over 900 degrees.

In order to make the waste heat usable in production, the family-owned business is investing around six million euros in conversion work; at the same time, Iqony is investing over two million euros in the required pipeline connection to the TRIMET production plant, which is around 700 meters long. The new connection pipeline will be integrated into Iqony’s existing district heating network in Bergeborbeck near the stadium on Hafenstrasse.

“The greater part of the new pipeline route will be laid on the TRIMET site to connect with the new energy center which is being built there. Two pipelines are being laid for this. One will feed the heated water into the district heating network, while the other will return the cooled district heating water to the energy station for reheating,” explains Peter Donsbach, who is managing the project on behalf of Iqony Fernwärme.

More climate-friendly industrial production and heat supply

“By using waste heat, we are taking a significant step in our sustainability program to make our company fit for the future and secure the production sites in the long term,” says Dr. Andreas Lützerath, member of the Executive Board of TRIMET Aluminium SE. “Our development work to adapt technology and digitalize processes not only makes the district heating project possible, but also enables us to make aluminum production more flexible, and in doing so makes a significant contribution to the energy transition.” TRIMET is pursuing the goal of producing aluminum in a climate-neutral manner by 2045.

For Iqony Fernwärme, the project is a further important step towards gradually decarbonizing the district heating supply, i.e. structurally reducing CO2 emissions, in Essen, Bottrop and Gelsenkirchen. Iqony Fernwärme has set itself the goal of becoming climate-neutral by 2045 at the latest. “To achieve this, we are currently working on a concrete roadmap on how to achieve climate neutrality. The waste heat utilization now agreed is an important building block in these considerations,” says Matthias Ohl, Technical Director of Iqony Fernwärme.

The cooperation therefore creates real benefits for district heating customers: district heating will be even better in terms of its climate footprint. The fact that we have succeeded in doing this together with TRIMET is a great success and shows what is possible when a common goal is pursued in partnership,” Matthias Ohl is pleased to add.

Project ensures security of supply

Moreover, in the current energy crisis, it is also strategically advantageous with a view to security of supply that Iqony Fernwärme is broadly positioned in terms of its heat procurement sources, explains Matthias Ohl. “One of our particular goals is to ensure security of supply. The cooperation with TRIMET also contributes to this by opening up a new, additional source of heat.”