Making bioethanol from steel

Energy-intensive industries cause roughly 15% of worldwide CO2 emissions. The world’s largest steel manufacturer will deploy a pioneering technology to make its production greener and contribute to the circular carbon economy.

A blast furnace uses coal to chemically reduce iron ore into iron, which is then further processed into steel. It releases large amounts of greenhouse gases CO and CO2 in the process. In Europe, steelmakers capture these by-product gases, transforming them into electricity and useful heat. But then the CO2 is released into the atmosphere.

That makes integrated steel plants a key area for decarbonisation. Big steelmaker ArcelorMittal Belgium is implementing a first of its kind, innovative technology at a scale and complexity that doesn’t exist anywhere in the world yet. The project is in line with ArcelorMittal Europe’s carbon emissions reduction roadmap, which targets a 30% reduction by 2030 and carbon neutrality by 2050.

The installation captures the CO- and CO2-rich off-gases emitted from the blast furnace and transforms them into ethanol through a gas fermentation process that uses microbes (Carbalyst^® project). This technology was developed by the US firm LanzaTech, with which ArcelorMittal has partnered for a decade.

There’s a second step to the project, too. Since carbon is currently used as an input to the blast furnace in the form of fossil coal, the company intends to partly replace this fossil carbon with waste wood that has been treated to become bio-coal (Torero project). This substitution of fossil coal by a circular carbon is already a step towards the green transition.

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The project is economically viable because there is a large demand for ethanol, which is also easier to store and transport than electricity. Ethanol has many different applications. It can be used as fuel, blended with gasoline. It can also be converted into ethylene, a basic component of the plastics manufacturing process, thus contributing to the circular economy.

“This investment protects existing jobs by keeping the steel industry in Europe, where we need highly skilled people to design and operate these plants,” says Marc Tonteling, an engineer at the European Investment Bank.

With the combination of two innovative processes, the company targets the production of 80 million litres of bio ethanol, equivalent to the fuel used by 600 flights between New York and London. ArcelorMittal estimates the CO2 savings to be equal to the yearly emissions of 350 000 cars.

“I liked the enthusiasm and commitment of the people in Ghent, who want to make this project work,” Tonteling says. “We are taking a technological risk, but we want to support the industry, and if this is successful, it can lead to a more generalized production of circular carbon products as bio coal, recycled carbon fuels, bio ethanol and many others.”