Microbial electrosynthesis for CO ₂ conversion and methane production: Influence of electrode geometry on biofilm development

Electromethanogenesis is a process of microbial electrosynthesis (MES) in which electroactive microorganisms reduce carbon dioxide (CO2) to produce methane (CH4), using cathode as an electron donor. The efficiency this reaction greatly determined by the establishment robust community on biocathodes, eventually affects global performance bioreactor. Moreover, development biofilm depends several characteristics electrodes, more specifically their material and geometry. Since electrode geometry crucial parameter, study aims at evaluating sole influence shape installing carbon-based electrodes with two different constructions (brush felt) biocathodes electromethanogenic reactor for CO2 capture. overall reactors showed coulombic efficiencies around 100%, high-quality biogas reaching concentrations above 90%. results reveal that individual biocathode performance, brush bigger contribution current generation electrical capacitance, exhibiting higher peak hydrogen production compared felt, could be reflected capture generation. Both geometries greater proliferation archaea over bacteria (between 53 85%), was significant than felt. Archaea dominated Methanobacterium felt codominated Methanobrevibacter while analyses very similar both geometries. © 2022 Authors. Greenhouse Gases: Science Technology published Society Chemical Industry John Wiley & Sons Ltd.