Power to gas technology converts electrical energy into chemical energy. If excess of the renewable energy is used for the conversion, the technology is suitable for storage and compensation of accumulated residual loads. The first step is the electrolysis of water, in which H2O is decomposed into H2 and O2 by using electrical energy. One possible follow-up process is the chemical methanation of CO or CO2, which reacts with H2 to CH4 and H2O. For example, biogas plants, chemical plants or steel mills are suitable sources of CO2. Synergy effects can be achieved in the combination with PtG-plant. Aim of this work was a further development of the existing laboratory plant for the methanation at the Chair of Process Engineering of Industrial Environmental Protection. The three-stage fixed bed methanation plant has been optimized by new pressure reactors and pressure vessels, as well as a shorter pipe run. In addition, a magnetic metering pump for water vapour into the educt gas was put in operation. In order to follow the future adaptations on the plant, a 3D-plan of the current structure was created. Furthermore, one-stage and three-stage series of experiments with different operating parameters were carried out for a validation of the plant. The test results were elaborated and compared with measured data from the old methanation plant.