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

The research company “CI4C” – Cement Innovation for Climate, founded by the four cement manufacturers Buzzi Unicem SpA/Dyckerhoff GmbH, HeidelbergCement AG, SCHWENK Zement GmbH & Co. KG, and Vicat S.A., has commissioned thyssenkrupp BU Polysius to construct a polysius® Pure Oxyfuel kiln system at the cement plant site in Mergelstetten, southern Germany.

The polysius® Pure Oxyfuel process is an innovative clinker production technology in which the ambient air normally used in the kiln combustion process is replaced by pure oxygen. Compared with conventional plants, this novel process aims to concentrate, capture, and make available for further use nearly 100% of the CO₂ generated, in a cost-efficient manner. The medium-term objective is to use renewable energy to further process the captured CO₂ into so-called “reFuels”, enabling the production of climate-neutral synthetic fuels, such as aviation kerosene.

Advantages of polysius® Pure Oxyfuel Technology:

In the conventional clinker-burning process, oxygen is supplied from the ambient air fed into the system. Since ambient air contains approximately 21% oxygen, its use introduces large quantities of nitrogen into the process. As a result, the CO₂ concentration in the exhaust gas is only around 25% to 30%.

By supplying pure oxygen through the polysius® Pure Oxyfuel process, atmospheric nitrogen is eliminated from the clinker-burning process. This significantly reduces the gas volume and enables a high concentration of CO₂ in the exhaust gas, allowing nearly 100% of the climate-damaging carbon dioxide to 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.