Biological electromethanogenesis is a promising technology which can be applicable to convert geologically-stored CO2 into CH4 by electrochemical active microorganisms as biocatalysts. To gain biocatalysts applicable within CO2-storage reservoirs, a Microbial Fuel Cell (MFC) was used to enrich electrochemical active microorganisms in reservoir brine sample from a petroleum reservoir. The MFC began to produce electricity after 25 hours of inoculation and reached the first maximum current at 50 hours post inoculation. The maximum power density of the thermophilic MFC was ca. 1003 mW/m2, higher than that of most thermophilic MFCs reported previously, suggesting that subsurface reservoir harbors highly functional biocatalysts.
Fu, Q., Kobayashi, H., Kawaguchi, H., Vilcaez, J., & Sato, K. (2013). Identification of new microbial mediators for electromethanogenic reduction of geologically-stored carbon dioxide. In Energy Procedia (Vol. 37, pp. 7006–7013). Elsevier Ltd. https://doi.org/10.1016/j.egypro.2013.06.635