Converting steel mill gases into chemicals

German steelmaker thyssenkrupp has produced ammonia from steel mill gases and is hailing the breakthrough as a further milestone in the Carbon2Chem project, which is being funded by the Federal Ministry of Education and Research (BMBF).

According to thyssenkrupp, it’s latest news represents the first time anywhere in the world that steel mill gases, including CO2, have been converted into ammonia, a chemical used to make fertilisers to improve food production.

Last year, thyssenkrupp produced methanol from steel mill gases, as part of the Carbon2Chem project, which is co-ordinated by the steelmaker, the Fraunhofer-Gesellschaft and the Max Planck Society, plus 15 other partners from industry and research.

If implemented on an industrial scale, the process, claims thyssenkrupp, could make around 20Mt of annual CO2 emissions from the German steel industry commercially viable – and could be used in other CO2-intensive industries.

Reinhold Achatz, head of technology at thyssenkrupp, commented: “Our Carbon2Chem concept has shown that it is possible to use steel mill gases for the production of various chemicals and thus achieve a circular carbon economy. Our goal is the large-scale industrial use of the technology.” 

Carbon2Chem is based on the fact that steel mill gases contain valuable chemical elements, including carbon in the form of carbon monoxide and carbon dioxide (CO2), nitrogen and hydrogen. They are, therefore, suitable for the production of carbon- and hydrogen-containing synthesis gas, a precursor for various chemicals. Examples include plastics and higher alcohols as well as ammonia and methanol. In the chemical industry, synthesis gases have so far been obtained from fossil fuels such as natural gas or coal. Carbon2Chem not only converts the CO2 contained in the steel mill emissions but also saves the CO2 arising when synthesis gas is produced from fossil carbon sources.

The first ammonia production took place in the Carbon2Chem technical centre in Duisburg, a pilot plant in which laboratory results are validated under practical industrial conditions using gases from regular steel mill operation. According to thyssenkrupp, this work forms the basis for transferring the technology to an industrial scale. The company has invested 33.8 million euros in the pilot plant on top of 8.5 million euros of BMBF funding for equipment and operation.

Thyssenkrupp believes that the solution, which was developed in Duisburg, could be transferred to over 50 steel mills worldwide and is holding talks with interested parties from various regions on how the technology could be applied to other CO2-intensive industries.