Aluminium Dunkerque, Trimet, Rio Tinto, and Fives Group, all part of the C4Capture consortium, achieved a key milestone in their collaboration in their joint development of a CO₂ capture solution for the aluminum industry. The companies started up pilot tests in real industrial conditions at the Aluminium Dunkerque smelter in Dunkerque and Trimet’s smelter in Saint-Jean-de-Maurienne, both in France.
The C4Capture Project
Aluminum is a key element for decarbonization, playing a central role in lightweighting vehicles and its share in automotive applications is expected to rise by 13% between 2014 and 2050. It also supports growing demand driven by electrification and the replacement of single‑use plastics, such as replacing plastic bottles with aluminum cans. In addition, aluminum’s exceptional recyclability makes it a cornerstone of the circular economy.
However, the primary production process is carbon intensive, accounting for 2% of global emissions of greenhouse gases, with an average of 16.1 tonnes of CO₂ emitted per tonne produced. French aluminum producers are already well below this average (4 t CO₂/t Al), but are now aiming for net zero emissions.
The C4Capture consortium was first announced in October 2023, with the aim of developing a carbon capture technology for the aluminum industry. The purpose is to achieve a 50% reduction in direct CO2 emissions (excluding energy sources) from primary aluminum production by 2030.
Working in partnership ensures the development of solutions that meet real-world needs and are immediately tested in actual operating conditions. Aluminium Dunkerque and Trimet at Saint-Jean-de-Maurienne have combined their expertise to help develop this technology at their respective sites. Rio Tinto, one of the world’s largest aluminium producers, has brought its expertise in the electrolysis process. Meanwhile, Fives brings over 60 years of experience in capturing and treating gas emissions from primary aluminum production.
The project faced several major challenges in the development of an innovative CO₂ pre-concentration system, which uses mini hoods, aimed at achieving levels close to gas industry standards. In addition, a testing system needed to be designed based on amine (organic compounds containing nitrogen and hydrogen) absorption technology adapted to the specific characteristics of gases produced by aluminum electrolysis pots.
After the conception and ordering, the prototypes were installed at the Dunkerque and Saint-Jean-de-Maurienne smelters between 2024 and 2025 (with the Aluminium Dunkerque pilot container being delivered in November 2025, as pictured above).
In January 2026, the project partners jointly started up the pilot tests at both smelters. These trials, which will take place throughout the year, mark a decisive step in confirming the technical and economic feasibility of the solution and guiding strategic decisions for the industrial phases.
Industry Support
In addition, this project is supported by the French Government as part of the France 2030 plan and was selected as a winner of the DEMIBaC call for projects (which stands for demonstration and industrial adoption of low‑carbon production solutions), led by ADEME (the French Agency for Ecological Transition). This recognition confirms the relevance and ambition of the consortium’s approach to accelerating the decarbonization of the aluminum industry.