Innovation in aluminium smelters

Trimet Aluminium SE is using a new process control system to optimise the electrolysis furnaces in its aluminium smelters. The system allows for consistent and forward-looking management of the company’s aluminium production, which it is aiming to make net zero.

The different control systems used at the company’s Essen, Hamburg, Voerde and Saint-Jean-de-Maurienne facilities are being replaced with its in-house control and monitoring system, Metrics. In Essen, 16 electrolysis furnaces are already equipped with the new system, while another 40 are ready to go live. “Metrics allows us to simultaneously negotiate a number of the challenges we face when it comes to the future of aluminium production,” says Dr Andreas Lützerath, a member of the executive board at Trimet Aluminium SE. “We are using it to support flexible control of the electrolysis process so that it can be adapted to a fluctuating power supply as well as laying the foundation for decarbonised aluminium production.”

The new process control system allows electrolysis to adapt flexibly to grid conditions by linking it to a forecasting programme that predicts process parameters. The assistance offered by this digital twin makes it possible to promptly work out how changes in the production process will cause the electrolytic cell to respond during operation. As a result, the amount of energy required by the electrolytic cells can be matched up with the fluctuating renewable energy supply.

Trimet has developed an innovative solution that makes it possible to adjust electrolysis in line with the fluctuating availability of electricity from renewables. Intelligent load control enables the aluminium smelter to respond to the variable volumes of wind and solar power fed into the grid. Special heat exchangers connected to the electrolytic cells ensure that the temperature in the furnaces remains stable. Trimet is also researching a new type of inert anode that emits oxygen instead of carbon dioxide during aluminium production. This futuristic process requires new furnace technology, which Trimet is designing with the help of Metrics. The furnace design is being tested using a mathematical model. One of the next steps is for Trimet to validate the design with an industrial-scale demonstrator.