Pilot Trials Begin for Aluminium CO₂ Capture

Fives, Aluminium Dunkerque, Trimet and Rio Tinto have started pilot trials of a CO₂ capture solution tailored to primary aluminium production. The C4Capture consortium initiated testing under real operating conditions on 14 January 2026 at the Aluminium Dunkerque site, following prototype design, procurement and installation between 2024 and 2025. Trials will continue throughout the year at Dunkerque and Saint-Jean-de-Maurienne to validate technical and economic feasibility before potential industrial deployment.

Targeting Direct Emission Reductions in Aluminium Smelting
The project aims to contribute to a 50 % reduction in direct CO₂ emissions (excluding energy-related emissions) from primary aluminium production at Aluminium Dunkerque by 2030.

Primary aluminium production accounts for approximately 2 % of global greenhouse gas emissions, with a global average of 16.1 t CO₂ emitted per tonne of aluminium produced. French producers currently operate at around 4 t CO₂ per tonne, significantly below the global average, and are pursuing further reductions toward net-zero targets.

The pilot programme is intended to assess whether dedicated capture systems can be integrated into aluminium electrolysis processes without disrupting production performance.

Addressing Technological Barriers in Electrolysis Gas Capture
Capturing CO₂ from aluminium smelters presents specific challenges due to the characteristics of gases emitted from electrolysis pots. The consortium developed an innovative pre-concentration system using mini hoods designed to collect and concentrate CO₂ streams closer to gas industry standards.

In addition, the testing phase includes an amine-based absorption system adapted to the chemical composition and operating conditions of electrolysis off-gases. Amine absorption is a proven carbon capture method in other industrial sectors, but adaptation is required to manage temperature, flow variability and impurity levels typical of aluminium production.

The pilot installations will evaluate performance parameters such as capture efficiency, operational stability and energy consumption under continuous plant conditions.

Public Support and Industrial Demonstration
The project has been selected under the DEMIBaC programme (Demonstration and Industrial Adoption of Low-Carbon Production Solutions), led by ADEME as part of the France 2030 plan. The programme supports industrial-scale demonstration of decarbonization technologies prior to large-scale implementation.

Real-condition trials are intended to generate operational data necessary for strategic decisions regarding industrial roll-out, including integration with existing smelter infrastructure.

Collaborative Development Model
The C4Capture consortium combines complementary industrial expertise. Aluminium Dunkerque and Trimet are hosting and developing the technology at their respective sites. Rio Tinto contributes expertise in aluminium electrolysis processes, while Fives provides more than 60 years of experience in gas capture and treatment systems for primary aluminium production.

This partnership-based approach enables prototype systems to be tested directly within operating smelters, reducing the gap between laboratory validation and industrial application.

Aluminium in the Low-Carbon Transition
Aluminium plays a central role in decarbonization strategies due to its use in vehicle lightweighting, electrification infrastructure and its high recyclability. Demand growth in automotive and electrified applications increases pressure to lower the carbon intensity of primary production.

By launching pilot-scale CO₂ capture trials under real operating conditions, the consortium aims to demonstrate a pathway for reducing process emissions in a sector that remains carbon-intensive despite efficiency gains in European production facilities.