From the frames of our buildings and bridges, to the moving parts of machines massive and minute, steel is almost literally the backbone of the modern world. The principles of steelmaking have changed little over the centuries, using blast furnaces to smelt the iron ore with charcoal. But the process is dirty, producing 'top gas', which contains nitrogen and carbon dioxide (CO2). Now, however, a European Union research project is offering the prospect of greener steel by revolutionising blast furnaces.
© Fotolia, 2012
The project, called Ultra-Low CO2 Steelmaking (ULCOS), is researching innovative ideas to slash the steel industry's carbon emissions. It is a consortium of 48 steel, energy and engineering partners, research institutes and universities from 15 European countries - including ten companies representing 95% of Europe's total steelmaking industry. By combining various emerging technologies, it promises to halve carbon emissions in steelmaking.
The first six-year phase, which was completed in 2010, was backed by a â¬30 million grant from the European Commission. A second phase, to be continued until 2025, ULCOS II, was launched in 2010 and has applied to the NER-300 programme, which could bring funding of several hundred million euro. If successful, the results from ULCOS could potentially be rolled out in production plants some 15 to 20 years from now.
"This is the largest research project the global steel industry has ever launched, and Europe is leading it," says ULCOS project coordinator Jean-Pierre Birat. "It shows that the steel sector is serious about global warming."
Birat, who also works in ArcelorMittal's Global Research and Development unit, says the consortium investigated over 80 new technologies including enhanced blast furnaces, modern smelting reduction, direct reduction, and electrolysis techniques. "But the technologies had to demonstrate credibly they could cut emissions. And that they could be scaled up," he says.
Birat says ULCOS was not only able to reduce emissions, but also cut energy consumption by 10 to 20%. With some 1.5 billion tonnes of steel produced worldwide annually, that represents hefty emissions cuts and energy savings.
ULCOS eventually focused on four promising concepts:
- Top gas recycling:This removes the CO2 and recycles the carbon monoxide (CO) back into the blast furnace, potentially using less than half the emissions of today's state-of-the-art blast furnaces. ULCOS has already successfully pilot tested top gas recycling at an experimental blast furnace that produces 35 tonnes of steel per day at the Swerea Mefos research facility in LuleÃ¥, Sweden. The project is now set to test the process at two planned full-scale blast furnace steel plants: EisenhÃ¼ttenstadt, Germany, capable of producing 2,000 tonnes of steel a day; and Florange, France, capable of 4,700 tonnes a day.
- HIsarna steelmaking: This processes iron ore almost directly into steel, thus skipping the manufacturing of pig iron pellets. More energy-efficient than traditional steelmaking processes, it could reduce the carbon footprint by up to 20%.
- Alkaline electrolysis: This is already used in industrial nickel, aluminium and zinc production. It could eventually replace the blast furnace altogether by passing an electric charge through an alkaline solution to separate the iron from iron ore.
- ULCORED: This involves producing direct-reduced iron (DRI) from iron ore with a reducing gas.
Each of these technologies (except electrolysis) has to combine with Carbon Capture and Storage (CCS) technology to reach the 50% emissions cut. But at the planned CCS plant in Florange, up to 700,000 tonnes of CO2 are expected to be captured annually, and then pumped more than 1 kilometre underground.
Birat says there are different timescales for each of the technologies but he is optimistic that some, like the blast furnace, could be deployed in just over a decade. "We are trying some exciting ideas that have never been done before, and they could transform the way we make steel," he says.