Comment: Decoding aluminium’s carbon challenge will change the way we think about emissions

Yet, this overlooked industry harbours a unique decarbonisation challenge that could reshape the future of carbon capture technology altogether. Aluminium production carries a carbon footprint that might surprise many, but can’t be ignored: producing a single tonne of aluminium generates on worldwide average  up to 15 tonnes of CO2 - that’s five times more than steel and ten times more than cement. As clean energy technologies drive surging demand for aluminium in everything from electric vehicles to solar panels, this carbon intensive material certainly pays it forward - the conversation now is about how it evolves from a technical curiosity into an increasingly pressing decarbonisation imperative. 

This presents us with quite the dichotomy. While aluminium's total emissions may be lower than cement or steel in absolute terms due to lower production volumes, its role in the clean energy transition is set to expand dramatically, with worldwide demand for primary aluminium expected to grow by a further 50 per cent by 2050 versus today (that’s approaching 110 million tonnes). Given that aluminium is so fundamental to many green technologies, the challenge then lies in addressing how we can scale up production of a material so essential to decarbonisation while addressing its own significant carbon footprint.

The complexity stems from aluminium's unique emission profile. The industry's carbon footprint breaks down into two distinct categories: indirect emissions from power consumption, which many producers are already addressing through renewable energy, and direct process emissions from aluminium smelting. It's this second category - where CO2 is emitted at roughly one per cent concentration - that presents both our greatest challenge and, potentially, our greatest opportunity.

The carbon capture industry has historically focused on very high concentrations of CO2, like those found in natural gas processing. This makes perfect sense from an industrial evolution perspective - you start with the lowest-hanging fruit and the problems you can address most efficiently. However, in recent years, the focus has shifted more towards diluted emissions, such as the 15 per cent to 20 per cent CO2 concentrations found in the cement industry. Despite this progress, very diluted emissions, like those from aluminium smelting, remain largely unaddressed, creating a critical gap in carbon capture capabilities.  

The market dynamics are already shifting. Leading aluminium producers have begun differentiating their products based on carbon intensity, with some achieving footprints below four tonnes of CO2 per tonne of aluminium - significantly better than the global average but still far from net zero. This competition is being driven not just by environmental concerns but by growing demand from downstream manufacturers, particularly in the automotive sector, who are themselves under pressure to decarbonise their supply chains.

Looking ahead, the industry faces both regulatory and market pressures. Public procurement policies are beginning to include carbon footprint requirements, which could significantly influence demand for low-carbon aluminium. Meanwhile, the race to develop effective carbon capture solutions for these low-range concentrations is intensifying, as success here could unlock decarbonisation pathways for multiple industries facing similar challenges.

The solutions required must address two critical aspects: energy efficiency and practical implementation. Any viable technology needs to significantly reduce the energy required for carbon capture while being adaptable enough to integrate into existing industrial infrastructure - many aluminium smelters are 40+ years old, with strict space and operational constraints.

This challenge radiates far beyond aluminium production. The rapid expansion of AI infrastructure offers a telling parallel - hyperscale data centres are proliferating globally to meet exploding demand for compute power, with providers like Meta planning facilities that could consume up to 2GW of power. While renewable energy is the end goal, these centres will initially rely heavily on natural gas power plants. This creates another significant source of diluted CO2 emissions (typically in the range of two-to-five per cent concentration) that sit awkwardly between existing capture technology solutions.

The industry is asking for a fundamental rethink of how we approach industrial carbon capture. Rather than trying to adapt existing solutions designed for higher concentration levels, we need fresh approaches specifically optimised for these low emissions sources. This might mean exploring new capture mechanisms, novel materials, or innovative process configurations - but always with an eye toward practical implementation in real-world industrial settings.

As pressure mounts to scale up production of materials essential to clean technologies, we can no longer afford to overlook these harder-to-abate emissions sources. Success in tackling aluminium's unique carbon challenge could unlock solutions for multiple industries facing similar constraints. The real test now is not just developing new capture approaches, but scaling them rapidly enough to meet ambitious climate targets while enabling rather than constraining the clean energy transition. The aluminium industry may have started as a footnote in most decarbonisation discussions, but it could prove to be one of our most valuable testing grounds for the broader industrial transformation ahead.

Jean Philippe Hiegel, head of Growth and Strategy, RepAir Carbon