Biomethanation in a thermophilic biotrickling filter using cattle manure as nutrient media

Abstract

Hydrogenotrophic methanogenesis is a power-to-gas method, biologically converting CO2 to CH4 using H2 generated from electrical power. However, the low rate of gas-liquid mass transfer of H2 limits the hydrogenotrophic methanogens biocatalyst. We explored hydrogenotrophic methanogenesis using cattle manure as trickling solution by employing a thermophilic biotrickling filter (BTF) with a fixed bed of polyurethane foam. It was found that stable biomethanation was possible with 100% H2 conversion and specific methane productivity of 2.08 Nm3 m−3 d−1 at a gas retention time of 1.32 h under thermophilic conditions. The successful use of pasteurized cattle manure, a cost-effective nutrient would enable biomethanation to get one step closer to being economically feasible.