Biogas and wind power plant operators in Germany must find ways to monetise their surpluses and increase their energy output, as guaranteed feed-in tariffs through the Renewable Energy Sources Act (EEG) comes to an end this year. Biomethanation, a process that uses special microorganisms to convert green hydrogen (H2) and carbon dioxide (CO2) into storable methane, is one of the solutions. It also plays a vital role in the CO2 management cycle.

This is the background to the research project WeMetBio, which has come out of the Brandenburg University of Technology Cottbus-Senftenberg (BTU) in collaboration with the Flensburg University of Applied Sciences. The partners have teamed up to develop a methanation pilot plant in Schleswig-Holstein using the “trickle bed process”, with the objective of creating methane to feed into the natural gas grid or to store.

The big idea is to use CO2 from biogenic waste sources (raw biogas contains up to 55 percent CO2) and the hydrogen is to be generated by electrolysis powered by wind energy surpluses. The technology that will be used for the project was first patented by BTU in 2013. Flensburg University has selected two possible biogas plants for the trial: Bioenergie Schuby GmbH and Nissen Biogas GmbH & Co. KG (an agricultural biogas plant and post-EEG wind power plant in Nordhackstedt).

If the one-year feasibility study – which is being carried out in consultation with engineering experts Gicon GmbH – is fruitful, the second step will be the construction of a large pilot plant (with a reactor volume of up to 150 cubic metres) at the chosen site. The project has a budget of just under EUR 80,000.