Miner South32 lands government funds for electrification and emission cuts in alumina refining

The Australian Renewable Energy Agency (ARENA) is to commit $4.4 million in funding to Australian mining and metals company South32 to help it find ways to electrify steam generation at its Worsley Alumina Refinery in Western Australia.

The $8.72 million prefeasibility South32 Steam Electrification study will study two different technologies used to decarbonise steam generation, which is currently dependent on fossil fuels.

Alumina refining relies on a process known as the Bayer circuit, or Bayer Process, which requires heat in the form of steam to extract and refine alumina from bauxite.

The alumina refining industry is therefore Australia’s largest user of industrial process heat, with around 70 per cent of greenhouse gas emissions produced in alumina refining stemming from steam production, which is currently powered by fossil fuels such as coal or gas.

The South32 Steam Electrification study will assess four investment options for partial steam electrification, focusing on two technologies.

These are electric boilers, which generate steam directly using an electrode, and mechanical vapour recompression (MVR), which captures low-pressure waste vapour from the refining process for recompression to create pressurised steam for reuse.

Each technology has the potential to improve the efficiency of alumina refining and cut greenhouse gas emissions through the use of renewable electricity over fossil fuels.

“Decarbonising our operations is key to achieving our goals and targets,” said Vanessa Torres, South32 chief operating officer, referring to the company’s long-term goal of reaching net zero greenhouse gas emissions across all scopes by 2050, and targeting a 50 per cent cut in operational greenhouse gas emissions by 2035.

“Electrification of the steam generation process at Worsley Alumina’s refinery has the potential to further reduce the operation’s GHG emissions and we look forward to starting work on the project.

The Arena funding comes from the $400 million Australian government’s Industrial Transformation Stream (ITS) program, and will provide insight into decarbonising Australia’s alumina refining for the entire sector.

Arena has already supported an Alcoa effort to investigate and trial electric calcination, and a hydrogen calcination trial by Rio Tinto at its Yarwun refinery in Queensland.

“Meeting Australia’s emissions reduction targets will require businesses in the most energy intensive industries to incorporate renewables in their operations,” said Darren Miller, ARENA CEO. “Funding from ARENA will help South32 investigate innovative electrification options for steam generation that enable the use of renewable energy.”