The tests now started are an important part of Thyssenkrupp’s climate strategy to become climate-neutral by 2050. By 2030, emissions from the company’s own production and processes (scope 1 emissions) as well as emissions from the purchase of energy (scope 2) are to be reduced by 30 %. “We’ve set ourselves a clear goal with our climate strategy,” said Dr. Klaus Keysberg, member of the Executive Board of Thyssenkrupp AG responsible for the group’s materials businesses. “Steel production will play an important part in reaching our climate targets because the potential for reducing emissions is huge. That’s why we’re working flat out to drive the transition to hydrogen technology.”
Water vapor instead of CO₂
In the classic blast furnace process around 300 kg of coke and 200 kg of pulverized coal are needed to produce a ton of pig iron. The coal is injected as an additional reducing agent into the bottom of the blast furnace shaft through 28 so-called tuyeres. At the start of the tests hydrogen was injected through one of these tuyeres into blast furnace 9. It marks the start of a series of tests in which Thyssenkrupp Steel plans to gradually extend the use of hydrogen to all 28 tuyeres on blast furnace 9 and then, from 2022, to all three further blast furnaces. The advantage is that whereas injecting coal produces CO₂ emissions, using hydrogen generates water vapor. CO₂ savings of up to 20 % are therefore already possible at this point in the production process.
Support from state of NRW
The project is being funded under the IN4climate.NRW initiative launched by the state government and is scientifically supported by the BFI research institute. The state government gave funding approval for the first test phase in April 2019. NRW economics and digital minister Prof. Dr. Andreas Pinkwart: “The project is an important step on the path to a greenhouse gas-neutral industry and a good example of how key technologies can be developed in North Rhine-Westphalia. We need to keep driving the use of hydrogen in industry because it offers great opportunities, especially in steel production.”
From lab to industrial scale
The start of the test phase also marks the project’s transition to industrial scale. Preliminary investigations and simulations have been carried out over recent months. The tests in a working blast furnace take the project to the next level. “We want to reduce emissions with hydrogen while continuing to produce pig iron of the same quality,” explains Dr. Arnd Köfler, Thyssenkrupp Steel Europe’s Chief Technical Officer. “At the same time we are breaking new ground with the tests on blast furnace 9 so it is now a question of continuously analyzing and evaluating the furnace’s operation. The results will help us to widen the use of hydrogen to all 28 tuyeres.”
Hydrogen infrastructure more and more important
Following the conversion of the blast furnaces, Thyssenkrupp plans to build large-scale direct reduction plants, which will then be operating with hydrogen-containing gases, starting in the mid-2020s. The sponge iron they produce will initially be melted down in the existing blast furnaces but in the long term will be processed into crude steel in electric arc furnaces using renewable energies.
In Air Liquide the project has a partner on board for the injection tests who has expertise in the entire hydrogen value chain from production and storage to the development of end consumer uses. Gilles Le Van, CEO of Air Liquide Deutschland: “Hydrogen is the key to both the energy transition and industrial transformation. This special molecule can be both a raw material for industry and a medium for energy storage and recovery. At Air Liquide, we are convinced of the potential of a global hydrogen economy. Together, we are shaping Germany’s hydrogen future and contributing to the achievement of climate goals.”
_{(Source: thyssenkrupp Steel Europe AG)}