The project is a technical feasibility study investigating the use of renewable hydrogen to partially decarbonise alumina refining at Rio Tinto’s Yarwun alumina refinery in Gladstone, Queensland.
Rio Tinto’s alumina refining process in Australia contributes to global greenhouse gas emissions. Current calcination technology uses air and natural gas to calcine alumina hydrate, which forms part of the alumina refining process. Decarbonising alumina refining will require developing an alternative low emissions pathway to calcine alumina hydrate.
The project will look to the technical feasibility of using renewable hydrogen in calcination, and includes the following activities:
- Laboratory test work to provide confirmation of the calcination flow sheet and mass balance
- Engineering study to understand the technical and safety implications of storing and utilising renewable hydrogen at the Yarwun alumina refinery, including determining the feasibility for the renewable hydrogen supply
- Calcination retrofit engineering concept study to determine the technical feasibility of retrofitting a calcination unit to use renewable hydrogen for a pilot program at the Yarwun alumina refinery.
The results of the project will improve understanding as to the technical feasibility of replacing natural gas with hydrogen as part of the calcination of gibbsite in alumina refining. It will also improve understanding of whether the existing calcination technology can be retrofitted to integrate hydrogen, and whether hydrogen can be integrated safely.