Tag Archives: lignocellulosic biomass

Rio Tinto verifies use of Pilbara ore for low-carbon iron-making using BioIron

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Rio Tinto says it has proven the effectiveness of its low-carbon iron-making process using ores from its mines in Australia in a small-scale pilot plant in Germany, and is now planning the development of a larger-scale pilot plant to further assess its potential to help decarbonise the steel value chain.

The process, known as BioIron™, uses raw biomass instead of metallurgical coal as a reductant and microwave energy to convert Pilbara iron ore to metallic iron in the steelmaking process. BioIron has the potential to support near-zero CO2 steelmaking, and can result in net negative emissions if linked with carbon capture and storage, according to the company.

Over the past 18 months, the process has been tested extensively in Germany by a project team from Rio Tinto, Metso Outotec and the University of Nottingham’s Microwave Process Engineering Group. Development work was conducted in a small-scale pilot plant using batches of 1,000 golf ball-sized iron ore and biomass briquettes.

Rio Tinto Chief Commercial Officer, Alf Barrios, said: “Finding low-carbon solutions for iron and steelmaking is critical for the world as we tackle the challenges of climate change. Proving BioIron works at this scale is an exciting development given the implications it could have for global decarbonisation.

“The results from this initial testing phase show great promise and demonstrate that the BioIron process is well suited to Pilbara iron ore fines. BioIron is just one of the pathways we are developing in our decarbonisation work with our customers, universities and industry to reduce carbon emissions right across the steel value chain.”

BioIron’s potential was confirmed in a comprehensive and independent technical review by Hatch, the global engineering, project management and professional services firm, Rio said. Hatch noted the thorough work completed by the team and BioIron’s capacity to reduce greenhouse gas emissions while converting Pilbara iron ore into iron and steel.

The BioIron process will now be tested on a larger scale, at a specially designed continuous pilot plant with a capacity of 1 t/h. The design of the pilot plant is underway and Rio Tinto is considering suitable locations for its construction.

The BioIron process works using lignocellulosic biomass including agricultural by-products (eg wheat straw, canola stalks, barley straw, sugar cane bagasse) or purpose-grown crops. The biomass is blended with iron ore and heated by a combination of combusting gases released by the biomass and high-efficiency microwaves that can be powered by renewable energy.

Rio says it is aware of the complexities around the use of biomass supply and is working to ensure only sustainable sources of biomass are used. Accordingly, the company is undertaking a benchmarking study of biomass certification processes. Through discussions with environmental groups, as a first step Rio Tinto has ruled out sources that support the logging of old growth and High Conservation Value forests.

Rio Tinto and Uni of Nottingham partner on biomass-backed low-carbon steelmaking project

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Rio Tinto says it is progressing an innovative new technology to deliver low-carbon steel, using sustainable biomass in place of coking coal in the steelmaking process, in a potentially cost-effective option to cut industry carbon emissions.

Over the past decade, Rio Tinto has developed a laboratory-proven process that combines the use of raw, sustainable biomass with microwave technology to convert iron ore to metallic iron during the steelmaking process. The patent-pending process, one of a number of avenues the company is pursuing to try to lower emissions in the steel value chain, is now being further tested in a small-scale pilot plant.

If this and larger-scale tests are successful, there is the potential over time for this technology to be scaled commercially to process Rio Tinto’s iron ore fines, Rio said.

Rio Tinto Iron Ore Chief Executive, Simon Trott, said: “We are encouraged by early testing results of this new process, which could provide a cost-efficient way to produce low-carbon steel from our Pilbara iron ore. More than 70% of Rio Tinto’s Scope 3 emissions are generated as customers process our iron ore into steel, which is critical for urbanisation and infrastructure development as the world’s economies decarbonise. So, while it’s still early days and there is a lot more research and other work to do, we are keen to explore further development of this technology.”

Rio Tinto’s process uses plant matter known as lignocellulosic biomass, instead of coal, primarily as a chemical reductant. The biomass is blended with iron ore and heated by a combination of gas released by the biomass and high efficiency microwaves that can be powered by renewable energy.

Rio Tinto researchers are working with the multi-disciplinary team in the University of Nottingham’s Microwave Process Engineering Group to further develop the process.

The university’s Head of Department, Chemical and Environmental Engineering, Professor Chris Dodds, said: “It is really exciting to have the opportunity to be part of a great team working on a technology that, if developed to commercial scale, has the potential to have a global impact through decarbonising key parts of the steel production process.”

The use of raw biomass in Rio Tinto’s process could also avoid the inefficiencies and associated costs of other biomass-based technologies that first convert the biomass into charcoal or biogas, the company said.

Lignocellulosic biomass includes agriculture by-products (ie wheat straw, corn stover, barley straw, sugar cane bagasse) and purpose-grown crops, which would be sustainable sources for the process. Importantly, the process cannot use foods such as sugar or corn, and Rio Tinto says it would not use biomass sources that support logging of old-growth forests.

Trott added: “We know there are complex issues related to biomass sourcing and use and there is a lot more work to do for this to be a genuinely sustainable solution for steelmaking. We will continue working with others to understand more about these concerns and the availability of sustainable biomass.”

If developed further, the technology would be accompanied by a robust and independently accredited certification process for sustainable sources of biomass, Rio said.