catch4climate – The way to green cement production
At thyssenkrupp we want to drive the green transformation. In industry in particular a lot still needs to be done to achieve our climate targets. One solution to make the cement industry climate-friendly is the catch4climate project of the research society Cement Innovation for Climate (CI4C). The research society was founded by the four cement manufacturers Buzzi Unicem SpA - Dyckerhoff GmbH, HeidelbergCement AG, SCHWENK Zement GmbH & Co. KG and Vicat S.A. thyssenkrupp polysius was assigned to build a polysius® pure oxyfuel kiln system as part of the catch4climate project.
We spoke to Jost Lemke, a development engineer from the project team: "It is not only the first oxyfuel clinker burning plant ever, but also at the same time the first plant that has been planned based on our improved concept. The plant is thus a unique opportunity to study many different aspects of the oxyfuel process in one place and under industrial conditions," he said. "In addition to some technical challenges, the plant will be more compact and clearer compared to the conventional oxyfuel concept" continues Lemke.
What makes the polysius® pure oxyfuel process so special
In the clinker burning process commonly used to date, oxygen is used from the ambient air supplied. The oxygen content of the ambient air is about 21 %. By using the ambient air, nitrogen in particular is introduced into the system, so that the proportion of CO2 in the exhaust gas is only about 25 % - 30 %. By feeding pure oxygen with the polysius® pure oxyfuel process, atmospheric nitrogen is eliminated from the clinker burning process.
The gas volume is reduced considerably and enables a high concentration of CO₂ in the exhaust gas, so that almost 100% of the climate-damaging carbon dioxide can be concentrated. Expert Jost Lemke is certain:. "The process is an important building block with which CO₂ emissions in cement production can be significantly influenced."
On the way to a green cement industry
The processes to capture greenhouse gas emissions in the cement sector, affect the cement industry in almost all areas of the process chain. From raw materials to finished cement and concrete to recycling. thyssenkrupp Polysius is also involved in many other processes to influence greenhouse gas emissions, energy and resource consumption in cement production. Processes such as the polysius® booster mill or the "polysius® activated clay" clay calcination process play an important role. Optimizing cement grinding by making better use of solar and wind power can also minimize energy and thus CO2 emissions. Currently thyssenkrupp is researching a method to recycle concrete in the cement industry. According to Lemke, intelligent production planning together with optimized plants can significantly increase the use of renewable energy. This can reduce the need for electricity from coal and natural gas. "We are making great progress at the moment in the industrial development of the polysius® puren oxyfuel process," Lemke enthuses. He and the whole team are certain: the methods developed are the key to a green cement industry.
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