Michael Fleige is engaged in the currently highly relevant field of converting carbon dioxide (CO2) into usable materials, specifically the production of methane through the Sabatier reaction. As a novel approach, the author investigates the direct conversion from flue gas generated during the combustion of fossil fuels in power plants. The focus is on the influences of flue gas components such as residual oxygen, SO2, and NO2 on the activity of the catalyst as well as on the yield of the process. The author assesses these effects along with the challenges arising from the dilution of CO2 in flue gases, and critically relates the process engineering suitability of flue gases to alternative carbon dioxide sources in other industries.