From smelter to homes: TRIMET and Iqony unlock waste heat value

The process of channelling industrial waste heat from TRIMET’s aluminium smelter located in Essen has been launched by TRIMET Aluminium SE in partnership with Iqony Fernwärme GmbH. This launch directly aims towards incorporating carbon-neutral energy, which will aid in boosting the environmental efficiency of the district heating network, further solidifying the sustainability credentials of the local heat supply.

TRIMET Aluminium SE, which is deemed to be one of the largest aluminium producers in Germany and France, with this launch, will be able to feed nearly 31 thousand MW-hours of unavoidable waste heat annually. It is possible because the unavoidable waste heat generated during the process of electrolysis furnaces is converted into Iqony's district heating network. These are supplied to customers located in Gelsenkirchen, Germany, Bottrop and Essen. The amount is analysed to feed the demand appetite of 5,500 households.

Also read: Stonepeak in talks for AM Green stake as USD 20bn green deal takes shape in India

Matthias Ohl, the Managing Director of Iqony Fernwärme, stated, “With this project, TRIMET and Iqony demonstrate what the circular economy means in practice in an industrial nation. Instead of letting industrial waste heat dissipate unused, it is being reused in heating networks. Waste heat is a key building block for decarbonising heat supply.

On the other hand, Dr Andreas Lützerath, the Member of the Executive Board of TRIMET Aluminium SE, stated, “The fact that we are now heating thousands of homes with the waste heat from our facilities is a milestone for our company and for the region. This clearly shows how innovation drives the green transformation. By making aluminium production more flexible, we are moving closer to climate protection targets, strengthening the future viability of our production sites, and working together with Iqony to make an important contribution to energy security."  

After TRIMET converted the aluminium production to a fluctuating power supply generated from solar and wind, the use of the industrial waste heat became a strong possibility. During the production process, on the electrolysis furnace where the heat is captured, the heat exchangers are specifically installed. Through a tube bundle, the four ventilator stations are directly tied to water, which is being heated to 130 degrees Celsius.

Must read: Key industry individuals share their thoughts on the trending topics

Via the pipe system, the water reaches an energy centre and when it comes under high pressure, it transforms the heat into the water in the respective heating network.

The firm has installed a pipe system on the plant premises, which is 1.6km long. In this, 36 cubic meters of water are circulated. In addition to this, Iqony has developed a connecting pipe, which is nearly 700 meters long and links the energy centres with that of the connection plant located outside the plant premises.

This project perfectly aligns with the TRIMET and Iqony agreement, which was drafted back in 2023 for a 20-year cooperation in order to make use of waste heat generated from the aluminium production at the TRIMET site, which is located in Essen.

The facility will soon enter regular operations after the completion of the trial operations. As of now, several million dollars worth of investment has been pooled in for the project by both firms. 

To know more about the global primary aluminium industry 2026 outlook, book the report “Global ALuminium Industry Outlook 2026".