Pilot project to examine hydrogen use in alumina refining

Rio Tinto investigates whether renewable hydrogen can be used in alumina refining.

The project is in partnership with Sumitomo Corporation and the Australian Renewable Energy Agency. They are building a first-of-a-kind hydrogen pilot plant at the Yarwun alumina refinery in Gladstone, Queensland, Australia.

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

The programme is aimed at demonstrating the viability of using hydrogen in the calcination process, where hydrated alumina is heated to temperatures of up to 1,000 degrees Celsius.

It will consist of construction of a 2.5MW 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 6,000t of alumina per year while reducing Yarwun’s carbon dioxide emissions by about 3,000t per year.

Construction will start in 2024. The hydrogen plant and calciner are expected to be in operation by 2025.