Rio Tinto’s Giant Microwave: Biomass to Cook Up Green Steel

BioIron™ proves successful for low-carbon ironmaking

Mon 10 Jun 24


Rio Tinto is reducing its reliance on coal and instead investing heavily in biomass—including AU $215 million into a new type of technology that will see the giant use biochar produced by trees and agricultural waste to make ‘green iron’ and ‘green steel.’

Known as BioIron™, the new technology uses raw biomass and microwave energy instead of coal to convert West Australian-based Pilbara iron ore into green iron. If all goes to plan, the new plant will be up and running, “producing one tonne of iron every hour” in 2026.

“Our modelling shows that when combined with renewable energy and carbon-circulation by fast-growing biomass, BioIron™ has the potential to reduce CO2 emissions by up to 95% compared with the current blast furnace method,” Rio Tinto said in a media release last week.

The global steel industry contributes eight percent of global carbon emissions. Commercialising the production of green steel is one of the key priorities on the path to net zero. It’s no surprise that Rio Tinto, one of the world’s biggest iron ore producers, is investing heavily in this area. Footage courtesy of @abcaustralia.

According to WA Premier Roger Cook, the deal will see WA lead the world in producing “green steel.” Premier Cook added, “As one of the world’s largest iron ore producers, it makes sense for WA to lead the world in low-emission steelmaking.”

“The world needs low-carbon steel to reach net zero, and we are working to make this a reality by finding better ways to turn our Pilbara ores into steel,” said Simon Trott, the CEO of Rio Tinto. “BioIron is a world-first technology that has the potential to play a significant role in a low-carbon steel future.”

The investment sees the Rockingham-based BioIron Research and Development Facility include a pilot plant ten times bigger than the one used in Germany – the first time the technology has been tested at a semi-industrial scale. As part of the new process, iron ore fines are mixed with raw biomass material and heated using a combination of gas released by the biomass and high-efficiency microwaves powered by renewable energy, turning the iron ore into metallic iron.

According to Rio Tinto, the main attraction of the BioIron™ process is that, as studies have demonstrated, it uses less than a third of the electricity needed by other new technologies currently being trialled, such as those using hydrogen.

“We have proven the process works at a small-scale pilot plant, and now we’re planning to test it on a larger scale at our new BioIron™ Research & Development Facility,” the company says, adding that the pilot plant will be capable of producing one tonne of direct reduced iron per hour and will provide data for Rio Tinto to continue scaling the technology to a larger demonstration plant.

Once established, the plant will have 30 full-time employees and will include space for equipment testing to support further scaling up of the technology. It will also work alongside the University of Nottingham, Metso Corporation, and WA engineering company Sedgman Onyx.

BlueScope is Looking to Biochar Tech to ‘Future-Proof’ Steel

Last year, Wood Central revealed that BlueScope is also turning to biochar to slash emissions from steel production. It is working with the University of Wollongong, CSIRO, and the Australian Renewable Energy Agency (ARENA) to use biochar to transition from traditional steelmaking to ‘green steel production’ as part of a commitment to net-zero emissions by 2050.

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BlueScope is partnering with the University of Wollongong (WOW) and the Australian Energy Agency (ARENA) to explore potential pathways to decarbonise the steelmaking process at Port Kembla Steel Works.

The research, published in a series of reports on the ARENA website, highlights that the blended material could successfully bind. However, further research is required to assess transport efficiency, handling procedures, and operational changes to BlueScope’s Pulverized Coal Injection (PCI) Plant.


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