For the first time thyssenkrupp has produced ammonia from steel mill gases, marking the first time in the world that steel mill gases, including the CO₂ they contain, have been converted into ammonia.

The production represents a further milestone in the Carbon2Chem project, which is being funded by the German Federal Ministry of Education and Research (BMBF) to the tune of around €60 million ($69 million). In September 2018, thyssenkrupp succeeded for the first time in producing methanol from steel mill gases.

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.

—Reinhold Achatz, head of technology at thyssenkrupp

Carbon2Chem is a major project coordinated by thyssenkrupp together with institutes of the Fraunhofer-Gesellschaft and the Max Planck Society and involving 15 other partners from research and industry. Implemented on an industrial scale, the technology could make around 20 million tons of the annual CO₂ emissions of the German steel industry commercially utilizable.

Steel mill gas comprises 44% nitrogen, 23% carbon monoxide, 21% carbon dioxide, 10% hydrogen and 2% methane. It is 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. (Methanol production requires additional hydrogen, which thyssenkrupp is providing via electrolysis.)

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 center in Duisburg, a pilot plant in which laboratory results are validated under practical industrial conditions using gases from regular steel mill operation. This work forms the basis for transferring the technology to industrial scale. thyssenkrupp has invested €33.8 million in the pilot plant. On top of this comes €8.5 million euros from the BMBF funding for equipment and operation.

There is interest in Carbon2Chem outside Europe. The solution developed in Duisburg could be immediately transferred to over 50 steel mills worldwide. In addition, thyssenkrupp is already holding talks with interested parties from various regions on how the technology could be applied to other CO₂-intensive industries.

Resources

• Carbon2Chem: Chemie Ingenieur Technik: Vol 90, No 10 (emphasis on methanol production)