Rio Tinto shifts to renewable diesel at Kennecott

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Rio Tinto’s Kennecott mine in Utah now runs entirely on renewable diesel, giving it one of the lowest carbon footprints among US copper producers.

Rio Tinto shifts to renewable diesel at Kennecott
Kennecott copper mine / Archive © Shutterstock

Rio Tinto has completed the transition from conventional to renewable diesel for all heavy mining equipment at its Kennecott copper mine in Utah, giving the mine one of the lowest carbon footprints of any copper producer in the United States.

Kennecott’s fleet of 97 haul trucks and heavy machinery equipment at the mine, concentrator, smelter, refinery and tailings are now all fueled by renewable diesel sourced in the US. The renewable diesel being used is currently a combination of 90% soybean and the remainder of animal fat and used cooking oil.

This is expected to reduce the mine’s Scope 1 emissions by 450,000t, equal to eliminating the annual emissions of 107,000 cars. In addition, the switch to renewable diesel reduces PM2.5 (particulate matter less than 2.5 microns) emissions at the tailpipes of the haul truck fleet by 40%, a reduction equivalent to approximately 2.3 billion miles of light vehicle travel annually.

According to Rio Tinto, Kennecott has one of the lowest carbon footprints of any copper producer in the US, thanks to recent initiatives such as the closure of a coal-fired power plant, installation of a 5-megawatt solar farm, deployment of battery electric vehicles underground, and the transition to renewable diesel. The operation’s overall carbon footprint has now been reduced by more than 80% from 2018 levels.

Kennecott’s transition to renewable fuel will also make low-carbon fuel more accessible in the state of Utah. In partnership with Kennecott, HF Sinclair is dedicating two tanks to renewable diesel for the mine with each having a tank capacity of 18,000 barrels or 756,000 gallons.

In 2023, Kennecott conducted an initial trial of renewable diesel, which compared two trucks using regular diesel against two using renewable diesel. Officials measured the trucks’ acceleration, cycle time, fuel usage, and engine inspection reports. The renewable diesel was trialled successfully, complementing similar test findings from Rio Tinto’s Boron mine in California.

Combined with Rio Tinto’s Boron mine – which completed the full transition of its heavy machinery from fossil diesel to renewable diesel in May 2023 – renewable diesel use at Kennecott replaces 11% of Rio Tinto’s global fossil diesel consumption with renewable diesel.

Rio Tinto is targeting reductions in Scope 1 and 2 emissions of 50% by 2030 and net zero by 2050.