Industry, academia and government collaboration is required to drive breakthroughs in greening aluminium.
Aluminium plays a vital role in aerospace, transportation, construction, and renewable energy infrastructure. However, its production is highly energy-intensive, making it one of the most challenging industries to decarbonise. Monash University’s Alcoa distinguished professor Christopher Hutchinson said the complexities of this transition must be overcome to ensure aluminium remains sustainable in a low-carbon future.
The multi-step challenge of aluminium production
“It is important to understand that the aluminium production process consists of multiple steps,” Hutchinson said.
“There is the mining of bauxite, its crushing and preparation, the refining of bauxite into alumina, and the smelting of alumina into aluminium. All three steps are important.”
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Smelting consumes the largest amount of energy, but refining also requires significant power. Decarbonising aluminium production means addressing all these stages comprehensively. Recent media attention has focused on smelting, where alumina (Al2O3) undergoes electrolysis to extract aluminium. The smelting process demands an immense amount of electricity, highlighting one of the industry’s greatest decarbonisation challenges.
“The challenge of decarbonising that electricity is truly enormous,” he said.
“A typical aluminium smelter consumes so much power that South Australia’s big battery – one of the largest in the world – could only run it for a few minutes. The electricity must also be reliable and continuous. If the electrolysis cells solidify due to a power outage, they are effectively ruined.”
Addressing carbon emissions beyond electricity
Aluminium smelting relies on consumable carbon electrodes to conduct electricity, which react with the oxygen released from the alumina (Al2O3) to form carbon dioxide.
“An aluminium smelter actually produces more carbon dioxide than aluminium,” Hutchinson said.
“We either need effective carbon capture and storage or new smelter designs that do not use carbon electrodes. Many companies and research institutions are developing non-consumable electrodes, but none have reached full commercial scale yet.”
Beyond smelting, refineries rely on high-temperature heat for the Bayer process and calcination, which are mostly fuelled by fossil energy. Alternative heating methods must be developed to further reduce carbon emissions. Another critical issue is red mud, the by-product of the Bayer process. “At the moment, we just store it, and it remains an environmental liability,” he says. “We need better solutions for managing red mud.”
Australia as a leader in green aluminium
Australia is well-placed to become a leader in sustainable aluminium production, with good bauxite resources, refineries, and smelters.
“We also have a lot of renewable energy,” Hutchinson said. “But the challenge is using that energy efficiently and solving the problems of energy density and storage.”
Australia’s research institutions provide another advantage.
“We have world-class universities, CSIRO, and industry expertise that can contribute significantly,” Hutchinson said. “These challenges are so vast that we need a whole-of-nation effort to bring together research, industry, and government. Certainly there are already some activities addressing these problems but, considering the magnitude of the challenge, they need to be greatly expanded and magnified”
The push for green aluminium should be part of a broader national strategy for green metals.
“Aluminium is not the only important metal Australia produces,” he said. “We should be thinking about becoming a green metal powerhouse, adding value to iron ore, steel, copper, rare earths, and lithium while reducing carbon footprint.”
Strengthening industry–academia collaboration
Training the next generation of engineers and material scientists is critical to sustaining innovation in this field.
“Decarbonising aluminium production requires expertise across multiple disciplines – energy systems, chemical engineering, metallurgy, and materials science,” Hutchinson said. “We need to train more engineers and scientists and create incentives for them to enter the green metals industry.”
He notes that Australian industry struggles to attract enough engineering talent. “The national shortage of engineers is well understood, but in metallurgy and materials science which are critical to green metals development, it’s especially pressing. Universities have a key role to play in addressing this gap.”
Driving innovation and policy support
Radical innovations are required to transform aluminium production. “These are not minor tweaks to existing processes,” he said.
“For example, if non-consumable electrodes can be developed and made durable enough, smelters would need a complete redesign. The technical, material, and process challenges are enormous.”
“Decarbonising electricity for smelting is a great first step, but we need much more support across the entire green metals sector. A national approach – perhaps a National Institute for Green Metals – could bring together industry, research, and policymakers to drive coordinated efforts.”
Australia’s natural mineral resources have historically been a key to Australia’s wealth and our current standard of living. They now present a unique opportunity to lead in green metals production. “We need to add as much value as possible to these resources sustainably,” he said. “That will determine whether we become global leaders in this space.”
The necessity of aluminium in a sustainable future
“It’s easy to look at the high electricity demands, CO2 emissions, and red mud and question whether aluminium is worth it. But the reality is, there is no substitute,” Hutchinson said.
Aluminium is the second-most used metal globally after steel and is indispensable for many industries. “Without aluminium, modern aviation would not exist. You can’t build aircraft from steel – it’s too heavy. Electricity transmission would be far less efficient, as aluminium is the preferred material for power lines. It’s used in car radiators, solar panel frames, and increasingly in electric vehicles due to its lightweight properties.”
As demand for electric vehicles and renewable energy rises, aluminium consumption will increase.
“A future with widespread electric vehicles will require much more aluminium than today’s cars because of the weight constraints imposed by batteries,” Hutchinson said. “If we want to meet our climate targets while maintaining essential infrastructure, we must find a way to green aluminium production.”
Decarbonising aluminium is one of the toughest sustainability challenges in the metals industry, requiring technological breakthroughs, policy support, and workforce development. However, the urgency of the task is matched by its importance.
“This is a great challenge for Australia’s young scientists and engineers,” Hutchinson said.