Rio Tinto and Sumitomo to trial lower-carbon alumina refining

Rio Tinto and Sumitomo Corporation have announced they will build a ‘first-of-a-kind’ hydrogen plant in Gladstone as part of a $111.1 million program aimed at lowering carbon emissions from the alumina refining process. The Yarwun Hydrogen Calcination Pilot Demonstration Program received the green light after a $32.1 million co-funding boost from the federal government’s Australian Renewable Energy Agency (ARENA).

The program is aimed at demonstrating the viability of using hydrogen in the calcination process, where hydrated alumina is heated to temperatures of up to 1000°C. It involves construction of a hydrogen plant at the refinery and the retrofit of refinery processing equipment. If successful, the program could pave the way for adoption of the technology at scale globally.

“This pilot plant is an important step in testing whether hydrogen can replace natural gas in Queensland alumina refineries,” said Rio Tinto Aluminium Pacific Operations Managing Director Armando Torres. “At Rio Tinto we have put the energy transition at the heart of our business strategy, and this is one of the ways we’re working towards decarbonising our operations.

“We are proud to be developing this new technology here in Gladstone, in partnership with Sumitomo Corporation and with support from ARENA.”

The project will consist of construction of a 2.5 MW on-site electrolyser to supply hydrogen to the Yarwun refinery and a retrofit of one of Yarwun’s four calciners so it can operate at times with a hydrogen burner. The trial is expected to produce the equivalent of about 6000 tonnes of alumina per year while reducing Yarwun’s carbon dioxide emissions by about 3000 tonnes per year.

Converting the entire plant to green hydrogen could reduce emissions by 500,000 tonnes per year, which is the equivalent of taking about 109,000 internal combustion engine cars off the road.

Construction will start in 2024. The hydrogen plant and calciner are expected to be in operation by 2025. Sumitomo Corporation will own and operate the electrolyser at the Yarwun site and supply the hydrogen to Rio Tinto directly. The electrolyser will have a production capacity of more than 250 tonnes of hydrogen annually.

“We are excited to be delivering this hydrogen project together with Rio Tinto as our long-term partner with the support of ARENA,” said Sumitomo Corporation Energy Innovation Initiative Director Seiji Kitajima. “Demonstrating real-world applications of hydrogen in industrial settings with motivated partners is essential to reducing carbon emissions and working toward our company’s vision of achieving carbon neutrality by 2050. Through this demonstration, Sumitomo Corporation aims to venture into the commercialisation project to contribute to Rio Tinto’s decarbonisation.

“Sumitomo Corporation is proud to be working on yet another hydrogen project in Australia and contributing to Australia’s own emission reductions goals.”

The pilot plant follows the success of an AU$1.2 million feasibility study co-funded by Rio Tinto and ARENA that was announced in 2021.

Image: Yarwun alumina refinery. Rio Tinto.