The aim of the project is to demonstrate CO2 methanisation for the valorisation and utilisation of CO2 in the exhaust gas from cement plants without prior CO2 separation or capture to reduce fossil primary energy in the production process. Based on a novel principle of action - a self-regenerating sorption catalyst - it is demonstrated that CO2 from cement waste gases can be converted to CH4 with regenerative H2, despite ballast gases such as N2, thereby enabling the direct re-use of synthesized methane as primary fuel in cement processing in order to reduce the need for fossil fuel and to minimize the corresponding fossil CO2 emissions.