Rio Tinto announced that it would collaborate with Japan's Sumitomo Corporation to build a hydrogen plant in Gladstone, Queensland, as part of its efforts to reduce carbon emissions at its Yarwun alumina refinery. The trial technology could reduce emissions from a sector that accounts for up to 3% of total emissions in Australia, as well as one of Rio Tinto's most carbon-intensive operations.

The Australian Renewable Energy Agency will contribute A$32.1 million to a programme worth A$111.1 million ($74.58 million) to test lower-carbon alumina refining. The hydrogen plant will reduce Yarwun's carbon dioxide emissions by approximately 3,000 metric tonnes per year and will produce approximately 6,000 metric tonnes of alumina annually.

The project will include construction of a 2.5-megawatt on-site electrolyser to supply hydrogen to the Yarwun refinery, it said, adding that if successful, the program could pave the way for adoption of the technology globally.

"This pilot plant is an important step in testing whether hydrogen can replace natural gas in Queensland alumina refineries," Rio Tinto Aluminium Pacific Operations Managing Director Armando Torres said.

Sumitomo will own and operate the electrolyser, and supply hydrogen to Rio. The electrolyser will have annual hydrogen production capacity of over 250 metric tons.

Rio will explore the viability of using hydrogen in calcination, a process which heats up hydrated alumina to extremely high temperatures.