Thyssenkrupp Steel has this week launched a series of tests into the use of hydrogen in a blast furnace during regular operation.
At the start of the tests, hydrogen is being injected through one of the 28 tuyeres of blast furnace no.9 in Duisburg. The starting button was symbolically pushed by the economy minister of North Rhine Westphalia, which supports the projects financially. Another partner is gases maker Air Liquide. Tk Steel plans to gradually extend the use of hydrogen to all 28 tuyeres on blast furnace no.9 and then, from 2022, to all three further blast furnaces.
In the classic blast furnace process around 300kg of coke and 200kg of pulverized coal are needed to produce 1 tonne of pig iron. While injecting coal produces CO2 emissions, hydrogen produces only water vapor. CO2 savings of up to 20% are therefore already possible at this point in the production process, Kallanish hears from the steelmaker.
The use of hydrogen is meant to be taken to an industrial scale. Preliminary investigations and simulations have been carried out over recent months, before transferring the technology to regular operation. “We want to reduce emissions with hydrogen while continuing to produce pig iron of the same quality,” says Arnd Köfler, tk Steel chief technical officer.
Following the conversion of the blast furnaces, the company plans to build large-scale direct reduction plants, which will then be operating with hydrogen-containing gases, starting in the mid-2020s.