Ex-situ biogas upgrading in thermophilic up-flow reactors: The effect of different gas diffusers and gas retention times

• Biological biogas upgrading process was evaluated in up-flow reactors. Different types of gas distributers were investigated for upgrading. Biogas with more than 98% CH 4 produced ex-situ process. H 2 gas–liquid mass transfer rate can be improved using porous SiC distributor. Four different ceramic distributors (Al O 3 1.2 μm and 0.5, 7 14 μm) to increase biomethane formation during Each type diffuser tested independently at three retention times 10, 5 2.5 h, thermophilic conditions. production increased by increasing input flow all distributors, whereas concentration declined. Reactors equipped effectively content fulfilling natural standards. Microbial analysis showed high abundance hydrogenotrophic methanogens proliferated syntrophic bacteria, i.e. acetate oxidizers homoacetogens, confirming the effect alternate anaerobic digestion microbiome enhance methanogenesis. A detailed bioconversion model adapted simulate operation R 1 -R The shown effective simulation