As the recent report of the IPCC (Intergovernmental Panel on Climate Change) shows the anthropogenic greenhouse effect most likely is responsible for global warming. According to experts, the global climate could be stabilized if CO2 emissions are drastically reduced. But the use of fossil fuels in coming decades can not be reduced drastically because of the high dependency. Therefore new ways have to be found to minimize CO2 emissions. In order to reduce these emissions from combustion gases processes for removing CO2 and subsequent storage are developed. These procedures are known as CCS (Carbon Capture and Storage). The procedure in which the CCS technology can be integrated into existing systems and then removes CO2 from flue gases is known as Post Combustion Capture. This is a very energy-consuming and costly process. A lot of research potential lies in the investigation of new CO2-absorbents. This thesis describes experiments on a pilot plant next to a coal power plant. Two different absorbents for CO2 capture in terms of their separation and their energy consumption were tested. On the one hand trials with the currently most used absorbent MEA (Monoethanolamine) were performed at different operating parameters and the results compared with literature values. This made it possible to draw conclusions on the functionality of the system. Second, a newly developed ionic liquid was tested as an absorbent. The aim was to maintain stable operating points for different parameters over a longer period and to compare the energy consumption with the known MEA solution. The newly developed ionic liquid provided worse results with respect to separation efficiency and energy consumption compared to MEA.