BioUpgrade- Ex-situ biogas upgrading through biolo

BioUpgrade is aiming at developing an innovative, efficient and robust technology for biological biogas upgrade, utilising the indigenous hydrogenotrophic cultures of the anaerobic digestion process, and achieve a biogas methane concentration equivalent to natural gas (>95% CH4). More specifically, in this project we are going to develop an optimised ex-situ biogas upgrading technology in which CO2 contained in biogas (35-50%) is coupled with H2 and directly biologically converted to CH4 by hydrogenotrophic methanogenic mixed cultures. The upgrading process occurs in an external novel reactor configuration, in which the biogas stream from primary digestion processes (i.e. biogas plant) and the H2 are injected. The bioconversion of CO2 and H2 to CH4 is achieved by enriched hydrogenotrophic methanogens that naturally inhabits anaerobic digestion systems. Digested effluent from the biogas plant at very low Hydraulic Retention Time is also provided to the novel reactor configuration in order to supply with nutrients the microbial culture. This concept offers great advantages as the overall energy balance of the biogas plant is greatly improved by converting also the carbon in the CO2 into useful energy form (i.e., CH4).