MikMeth: Tailored energy supply by microbial methanation

 Due to an increasing amount of power generated from renewable resources in Germany, covering the fluctuating energy demand from industry and private households will become more and more challenging. Currently various available energy conversion and storage technologies (e.g. batteries, pump storage hydro power systems) are only applicable as short- or midterm storage due to limited capacity. In contrast, the gas grid has one of the largest long term storage capacities available. In this context the project aims to further study and develop the microbial generation of methane (as a storable gas) directly from hydrogen and carbon dioxide, which could be an efficient alternative to the well-known Sabatier reaction (chemical-catalytic process). The required hydrogen can be generated in times of excess power via electrolysis, the carbon dioxide streams could be used directly at their origin (e.g. industries, biogas plants). This research focusses especially on the investigation of flexible (on demand) and efficient operation of the microbial methanation process, being essential to be applied as a future energy conversion and storage technology.

Through establishing this process within an anaerobic trickle bed reactor it can be operated without pressurized gas supply, increasing the energy efficiency compared to fixed-bed, membrane or CSTR systems. Furthermore the influence of different inocula, process temperatures as well as carbon dioxide sources will be investigated with regard to the applicability of the process. The Bavarian State Research Center for Agriculture as our project partner will investigate the microbial composition, focusing on enriching dominant species of hydrogenotrophic methanogenic archaea during long-term and intermittent operation as well as on micro and macro nutrient requirements.