Carbon dioxide mitigation by carbon capture and storage (CCS) is a key technology to significantly reduce the level of carbon dioxide emissions. With that, the impact of the greenhouse effect will be mitigated. CCS involves the use of technology, first to collect and concentrate the CO2 produced in industrial and energy-related sources, transport it to a suitable storage location, and then store it away from the atmosphere for a long period of time. The main advantage of this technology is, that CCS would allow the necessary fossil fuels to be used with low emissions of greenhouse gases. In post-combustion capture with chemical absorption the cost of the capture process is primarily driven by the properties of the absorption solvent. Hence, the energy demand for regeneration of potential solvents should be as low as possible. Ionic liquids as a new generation of solvents are promising for capturing CO2 because they have advantages to other solvents. Ionic liquids are salts which are typically liquid at room temperature. Thus, ionic liquids are solvents where only ions are present. The main advantage of ionic liquids are the large variation possibilities of physical and chemical properties due to the enormous different combination alternatives of cation and anion. A further advantages is the non measurable vapour pressure, which reduces the solvent losses to a minimum. The present work evaluates different ionic liquids as potential solvents for post-combustion CO2 capture. Based on laboratory experiments followed by pilot plant tests directly at a coal fired power station, the CO2 capture performance and the energy requirements of one new ionic liquid was evaluated. Different new ionic liquids have been designed and tested in a laboratory screening apparatus. Based on these results one ionic liquid was selected and vapour-liquid equilibrium measurements were performed. These experiments were the basis of a theoretical calculation of the total energy demand for CO2 stripping from the loaded solvent. Direct comparisons with the reference solvent, a 30w% monoethanolamine (MEA) solution, under real flue gas conditions were performed directly in a pilot plant at a coal fired power station. Pilot plant tests showed the behaviour of both solvents, combined with the CO2 capture rate and the energy demand. From these tests it can be deduced that the selected ionic liquid has the potential to capture CO2 from flue gases.