Mining giant Rio Tinto has successfully completed its first renewable diesel trial across its Pilbara iron-ore operations, marking a milestone in its efforts to cut emissions and integrate alternative fuels into its supply chain.

The trial, conducted in partnership with renewable diesel producer Neste and Australian fuel supplier Viva Energy, provided Rio Tinto with insights into how biofuels can be scaled across its operations.

Neste allocated ten-million litres of renewable diesel derived from used cooking oil for the trial. Viva Energy transported the fuel from Singapore to Rio Tinto’s Parker Point fuel terminal in Dampier, where it was blended with fossil diesel to create a mix containing about 20% renewable diesel. The fuel was then distributed across Rio Tinto’s Pilbara network, including rail, marine, haul trucks, blasting operations, surface mining equipment, and light vehicles.

The four-week trial, conducted in January and February, reduced Rio Tinto’s Scope 1 emissions by about 27 000 t of direct greenhouse-gas emissions, equivalent to the tailpipe emissions from 6 300 cars over a year. The initiative also helped the company evaluate the bulk renewable diesel supply chain, importation, and blending processes.

“Diesel makes up about 70% of the total carbon emissions from our Pilbara iron-ore operations. While electrification is the ultimate longer-term solution for repowering the majority of our fleet, we’re also exploring biofuels as a complementary and nearer-term solution,” said Rio Tinto MD for rail, port and core services Richard Cohen.

Rio Tinto is exploring biofuels as part of its strategy to achieve a 50% reduction in Scope 1 and 2 emissions by 2030 and reach net zero by 2050. The company has already replaced 11% of its total global fossil diesel consumption with renewable diesel at its Boron and Kennecott operations in the US. Further, Rio Tinto is developing a Pongamia seed farm in North Queensland as part of a biofuels pilot to support the Australian biofuels industry.

This latest trial signals a step forward in Rio Tinto’s decarbonisation strategy, demonstrating the potential for renewable diesel to contribute to emission reductions in the mining sector.