Dresden – Steel production accounts for seven percent of global CO2 _emissions . Producing green hydrogen through electrolysis using electricity from renewable energy sources and using it in the steel industry instead of coal in a process known as direct reduction could potentially save up to 95 percent of carbon dioxide emissions in the production of crude steel. This is the conclusion of the "Feasibility Study for Reducing CO2 Emissions in Steel Plants Using Renewable Energies" (MACOR), funded by the German Federal Ministry of Education and Research (BMBF) and _conducted by the three Fraunhofer Institutes IKTS, ISI, and UMSICHT, as well as the Salzgitter companies Salzgitter Flachstahl and Salzgitter Mannesmann Forschung. The Fraunhofer Institute for Ceramic Technologies and Systems IKTS coordinated the project.

Among the questions to be clarified were how to assess the conversion of steel production to a more climate-friendly process, what this specifically means for the integrated steelworks of Salzgitter Flachstahl GmbH, and how much renewable energy is needed to save one ton of CO2 _. Salzgitter AG had a particular interest in the outcome, as the company aims to complete the conversion to virtually CO2-free crude steel production by 2050 as part of the SALCOS project ("Salzgitter Low CO2 Steelmaking") ₍ as _previously reported).

While Fraunhofer IKTS was primarily dedicated to process simulation, Fraunhofer ISI analyzed the economic viability of different process variants. The employees at Fraunhofer UMSICHT examined the processes involved in direct reduction as well as the properties of the reduced iron, according to a statement. At the Salzgitter companies, the focus was on drawing up an implementation plan for SALCOS, technical studies of directly reduced iron and ecological balancing.

A key metric is the energy required per ton of CO2 saved _. One finding: Avoiding CO2 _in crude steel production "is four times more efficient than capturing the CO2 _" and using it elsewhere, for example, in the production of chemicals. Hydrogen-based steel production offers a savings potential "of almost 100 percent compared to conventional methods, such as hydrogen injection into the blast furnace." Simulation calculations by the IKTS have shown "that high-temperature electrolysis is a very efficient and economical method for providing the hydrogen required for direct reduction in the integrated steelworks." Thus, the MACOR project has "confirmed the technical feasibility and advantages of our SALCOS approach," explains Alexander Redenius of Salzgitter Mannesmann Research.

In a follow-up project “Accompanying research on hydrogen in steel production” (BeWiSe), the consortium now wants to advance the optimization of the path to hydrogen-based steel production investigated with MACOR. This project is also funded by the Federal Ministry of Education and Research.

deep link
https://www.ikts.fraunhofer.de/de/presse/pressemitteilungen/29-9-2020-co2-emissionen-bei-der-stahlproduktion–von-100-auf-5-.html
https://salcos.salzgitter-ag.com

Photos
Smelter tapping the blast furnace at Salgitter Flachstahl: CO₂-Emissions from steel production could be reduced by 95 percent with hydrogen / © Salzgitter AG