EU GREEN STEELMAKING: ArcelorMittal, Thyssenkrupp report new blast furnace tests
ArcelorMittal and Thyssenkrupp Steel have both recently announced successful testing of methods to reduce carbon emissions in blast-furnace steelmaking via coke gas and hydrogen, the companies have reported separately.
ArcelorMittal has completed its coke gas injection project at the Alto B Furnace at its Gijón operations, Spain. This is intended to reduce its CO2 emissions by 125,000 tonnes per year, and its operating costs via lower consumption of coke.
ArcelorMittal Europe has two main technology methods to reduce its carbon emissions - Direct Reduced Iron (DRI) and Smart Carbon.
The DRI method involves the use of hydrogen in the direct-reduction process of iron ore in the electric steel mill and blast furnace, while Smart Carbon is a carbon-neutral method of pig iron manufacturing that uses clean energies such as circular carbon, clean electricity and carbon capture and storage (CCS).
In its first phase, Smart Carbon will primarily use circular carbon. This will subsequently be expanded to the use of hydrogen, when enough supplies of green hydrogen are available at affordable prices, the company says.
Included in the Smart Carbon approach, and within the projects that ArcelorMittal is developing in its Flat Products steel plants in Europe, is the use of gases from different sources for injection into the blast furnace. Injecting coke gas, with a high hydrogen content, is an effective and cost-efficient method that allows steel producers to reduce their CO2 emissions immediately, it has said.
ArcelorMittal Asturias has completed the most advanced project in the company related to the use of coke gas. Grey hydrogen - hydrogen recovered from various gases, including natural gas and coke gas - has been injected into the Alto B Furnace.
The Asturias project, to reduce CO2 emissions from the pig iron production process, reuses part of the gas generated in the coke batteries to partially replace the coke used in the high furnace.
Work to supply coke gas to the semi-finished reheating furnaces of the heavy plate and rail rolling mills should be completed in the coming weeks, reducing both the consumption of natural gas and carbon emissions.
These facilities process semi-finished steel from the Avilés and Gijón steel mills to produce thick plate and rail.
Oswaldo Suárez, ArcelorMittal’s chief executive for the Asturias Cluster, said that the injection of coke gas into the Alto B Furnace was a milestone in the transformation of the company’s processes toward a more sustainable production model.
Thyssenkrupp recently reported that it has successfully concluded the first phase of the injection of hydrogen into its Duisburg Blast Furnace 9.
Several tests on one of the 28 tuyères of the blast furnace have been conducted in recent months. This allowed the company to extend the tests to all tuyères in the next step and to transfer this technology to large-scale industrial use.
In November, Thyssenkrupp Steel injected hydrogen into a blast furnace during operation, and it says that it was the first company to do so.
The project is funded under the IN4climate.NRW initiative launched by the regional government in the area, and is scientifically supported by the BFI research institute and supplied with hydrogen by Air Liquide.
A key focus of the first test phase was plant technology for use with hydrogen. It found that it was possible to reach a hydrogen injection volume of about 1,000 cubic meters per hour.
“The development of the hydrogen technology at blast furnace 9 is an important step in our transformation toward climate-neutral steel production,” Arnd Köfler, chief technology officer of Thyssenkrupp Steel, said.
“We are very grateful to the state of North Rhine-Westphalia for funding this first trial phase, which has laid the foundations for the second phase,” he added. “This will be followed by the next decisive step toward climate neutrality - the construction of direct-reduction plants, which are purely hydrogen-based and can be operated completely without coal.”
The second test phase is scheduled to start in 2022, later than originally planned due to the Covid-19 pandemic. Tests will be extended to all 28 tuyères of the blast furnace.
The focus of research will then be on the effect of hydrogen technology on the metallurgical processes in the blast furnace.
While the hydrogen for the first test phase was delivered by truck, a pipeline will be required to supply enough hydrogen for the second phase.
A preparatory agreement for this supply via Air Liquide’s long-distance pipelines was concluded recently. Air Liquide was already a partner in the first project phase and, subject to funding approval, intends to invest in a new connection from the blast furnace to an existing long-distance hydrogen pipeline.