In situ electrochemical H₂ production for efficient and stable power-to-gas electromethanogenesis

Abstract

Bioelectrochemical power-to-gas presents a promising technology for long-term storage of excess renewable energy in the form of methane. The transition of the technology from laboratory to applied scale is currently...

Efficient Hydrogen Delivery for Microbial Electrosynthesis via 3D-Printed Cathodes

“…Exposure to alkaline pH environments can compromise microbial organisms like M. maripaludis (Schauer and Whitman, 1989). In fact, in a previous study we found slightly increased cell lysis of M. maripaludis cells grown with in situ electrochemically evolved hydrogen (at 1 mA/cm 2 ) compared to cultures supplied with a gaseous mix of H 2 /CO 2 (Kracke et al, 2020).…”

“…The archaeon M. maripaludis was chosen due to its salinity tolerance and its exceptional performance in previous studies ( Kracke et al, 2020 ). M. maripaludis was cultured using chemically defined medium-JD specifically modified for use in bio-electrochemical reactors as reported previously ( Kracke et al, 2020 ).…”

“…Each chamber was magnetically stirred at 700 rpm. All reactors were operated at ambient pressure in a temperaturecontrolled room at 30 • C. Prior to inoculation the system was operated for 72 h to reach stable pH conditions in the cathode chambers [see detailed description elsewhere (Kracke et al, 2020)].…”

Choice of Microbial System for In-Situ Resource Utilization on Mars

“…Light-independent, lithoautotrophy can fix carbon by relying on chemically provided reducing power. On Mars, this could either directly be electricity through microbial electrosynthesis in bio-electrochemical systems (Moscoviz et al, 2016;Abel et al, 2020;Chen et al, 2020a), or indirectly by means of hydrogen or (organoautotrophically) formate, both of which can also be generated electrochemically (Kracke et al, 2020;Abel and Clark, 2021). Use of other electron donors like, e.g., sulphide, sulphur and iron (II) is theoretically possible, but technically less feasible (crustal materials from Mars are in principle able to support lithotrophic growth (Milojevic et al, 2021), but mining and purifying these in quantities that could support biotechnological processes is likely not viable).…”

“…Some also present an explosion hazard. Integrated setups can, however, avoid explosive gas mixtures and achieve significant production rates (Kracke et al, 2020;Sahoo et al, 2021). To completely avoid these problems, methane could be further converted to methanol (Zakaria and Kamarudin, 2016;Latimer et al, 2018)-albeit poor conversion efficiency is a century old unsolved problem.…”