• Rio Tinto will buy locally produced bio pellets under a five-year agreement, with deliveries targeted to begin in 2028.
• Trials found bio pellets could replace up to 30% of the coal used to generate steam in alumina refinery boilers.
• Full contract volumes could cut reported Scope 1 emissions by up to 90,000 tonnes of carbon dioxide equivalent each year.

Rio Tinto has signed a five-year bio pellet supply agreement for its Gladstone alumina refineries, advancing efforts to reduce coal use in one of aluminium production’s most energy-intensive stages.

Australian bioenergy company SuperChar Limited, or SCL, will supply the locally produced fuel. Deliveries are expected to start in 2028.

The agreement follows operational trials and a feasibility study conducted by Rio Tinto. It will allow the miner to test bio pellets at a larger scale while assessing their technical and commercial role in alumina refining.

Trials show potential to reduce coal use

Alumina refineries require large volumes of heat and steam to process bauxite into alumina, the intermediate material used to produce aluminium. Coal remains an important energy source at Rio Tinto’s Gladstone operations.

During recent trials, the company tested several blends of coal and bio pellets. Under trial conditions, the renewable fuel replaced up to 30% of the coal used to generate steam in refinery boilers.

Rio Tinto now plans to conduct further operational demonstrations using blends containing between 5% and 50% bio pellets. The material will supplement coal rather than replace it entirely during the initial contract period.

The phased approach reflects the technical challenges facing heavy industrial decarbonisation. Refineries must maintain stable heat, pressure and steam output while testing fuels that may have different combustion characteristics.

Rio Tinto Aluminium Pacific Operations Managing Director Armando Torres said: “Reducing our alumina refineries’ reliance on fossil fuel will require a mix of technologies, innovation and partnerships, and bio pellets are one of the practical options we are exploring as part of that. The recent trials and feasibility study have given us valuable insights, and this agreement allows us to take the next step in understanding how bio-pellets could work in practice and be scaled for use at our Gladstone operations. The project also has the potential to support new industries and supply chains in Central Queensland, connecting agriculture and industry in new ways.”

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Local production could support regional supply chains

SCL plans to build a bio pellet production facility in the Gladstone region. The plant will use locally grown bana grass as its primary feedstock.

Bana grass is a high-yielding perennial energy crop suited to Central Queensland’s climate. Farmers can plant and harvest it using conventional sugar cane equipment. Once established, the crop can remain productive for more than 15 years.

The proposed facility will initially produce 35,000 tonnes of bio pellets annually. SCL is targeting a progressive rollout of bana grass planting from late 2026, followed by pellet processing in 2028.

At full contract volumes, the project could reduce Rio Tinto’s reported Scope 1 emissions by up to 90,000 tonnes of carbon dioxide equivalent each year. That estimate is based on Australia’s current National Greenhouse and Energy Reporting framework.

SCL Executive Chairman Michael Palmer said: “This agreement builds on several years of collaboration and demonstrates the potential for local, regeneratively grown biomass as an alternative industrial fuel, while creating opportunities for regional communities.We look forward to continuing our partnership with Rio Tinto and progressing the project with local stakeholders.”

Scaling depends on performance and feedstock integrity

The initial agreement gives Rio Tinto an opportunity to assess fuel performance before committing to larger volumes. Supply could increase over time if the demonstrations prove successful.

For investors and corporate leaders, the project highlights the growing role of transitional technologies in reducing industrial emissions. Electrification and hydrogen remain longer-term options for some high-temperature processes. Biomass can offer a nearer-term route where existing boiler infrastructure can accommodate blended fuels.

However, the climate value will depend on credible feedstock governance. Land use, farming practices, transport emissions and carbon accounting will shape the project’s overall emissions profile.

The agreement also links industrial decarbonisation with regional economic development. A successful project could create a new agricultural market while building local processing capacity in Central Queensland.

For Rio Tinto, the Gladstone trials form part of a broader effort to reduce the carbon intensity of aluminium production. Their commercial outcome could influence how other alumina producers approach fossil fuel substitution across Australia and international refining markets.