Recently, the new pilot-scale trickle bed reactor for the biological methanation of hydrogen and carbon dioxide has been installed at the Garching wastewater treatment plant. The Chair of Urban Water Systems Engineering researches the potential of biological methanation under anaerobic thermophilic conditions with so-called archaea, which use the supplied gases for their metabolism and thereby produce storable biomethane. In a previous project, methanation in anaerobic thermophilic trickle bed reactors at lab-scale already demonstrated a high performance with methane production rates of up to 15 LCH4/(Ltrickle bed*d) at methane concentrations in the product gas above 96 %.
With a reaction volume of 1 m3, the applicability of the reactor concept should be demonstrated on a semi-industrial scale. This makes the reactor one of the largest anaerobic trickle bed reactors in the world. Considering the location, an important research question is the use of raw biogas from the wastewater treatment plant’s digester as an alternative CO2 source. This would allow upgrading of biogas to grid injection gas quality at the point of origin.