Press Release: 9 June 2022 – polysius® Pure Oxyfuel Technology for CO₂ Capture in Cement Production

The research consortium “CI4C,” founded by the four cement manufacturers Buzzi Unicem SpA/Dyckerhoff GmbH, HeidelbergCement AG, SCHWENK Zement GmbH & Co. KG, and Vicat S.A. — Cement Innovation for Climate — has commissioned thyssenkrupp’s Polysius business unit to build a polysius® pure oxyfuel kiln system on the grounds of the cement plant in Mergelstetten in southern Germany.

The polysius® pure oxyfuel process is an innovative clinker production method in which the standard ambient air used in the kiln's combustion process is replaced by pure oxygen. Compared to conventional plants, this novel process aims to cost-effectively concentrate, capture, and repurpose nearly 100% of the CO  generated. The medium-term goal is to use renewable energy to further process the captured CO  into so-called 'reFuels,' thereby producing climate-neutral synthetic fuels, such as kerosene for aviation.

Advantages of polysius® Pure Oxyfuel Technology:

In the clinker firing process commonly used to date, oxygen from the supplied ambient air is utilized. The oxygen content of ambient air is approximately 21%. The use of ambient air introduces nitrogen into the system in particular, so that the CO  content in the exhaust gas is only about 25%–30%.

By introducing pure oxygen using the polysius® pure oxyfuel process, atmospheric nitrogen is eliminated from the clinker burning process. The gas volume is significantly reduced, enabling a high concentration of CO  in the flue gas, so that nearly 100% of the climate-damaging carbon dioxide can be captured.

The complex gas recirculation required in first-generation Oxyfuel processes is no longer necessary. This results in lower overall capital investment and operating costs for the polysius® Pure Oxyfuel process.