Pilot-scale study of biomethanation in biological trickle bed reactors converting impure CO2 from a Full-scale biogas plant

Abstract

Research within biological methanation has been a great development using biotrickling filters (BTF), as a power-to-x solution, but research within up scaling is missing. This study investigates the commercial potential of biomethanation in BTF by operating two 1 m3 reactors which was implemented into a full-scale biogas plant. Several areas were investigated, such as enrichment and start-up, long-term steady state operation, serial operation, and intermittent feed. A methane productivity of 9.44 NmCH43 mR-3 day-1 with a product gas of 95.7 % CH4 was obtained for parallel operation, whereas during serial operation a methane productivity of 10.6 NmCH43 mR-3 day-1 at 97.4 % CH4 was achieved. The flexibility of the biomethanation was demonstrated with unintentional loss of H2 feed in periods of 12 to 72 h, where initial performance was regained within 6 to 12 h. The results from this study demonstrate the potential for commercial use of biomethanation in BTF for future Power-to-X solutions.