Progress towards catalyzing electro-methanogenesis in anaerobic digestion process: Fundamentals, process optimization, design and scale-up considerations

Genome Analyses and Genome-Centered Metatranscriptomics of Methanothermobacter wolfeii Strain SIV6, Isolated from a Thermophilic Production-Scale Biogas Fermenter

“…In the future, a microbial-based process management [78] and thus an optimization of the performance and stability of the biogas process is intended. In recent research, selected methanogenic Archaea were used in electro-methanogenesis experiments pursuing the aim to reduce carbon dioxide to methane by electric current at a biocathode [79][80][81]. This 'power-to-gas' strategy is of great importance regarding conversion of electrical power into the storable energy carrier methane.…”

How Operational Parameters Affect Electromethanogenesis in a Bioelectrochemical Power-to-Gas Prototype

“…Thermovirga was previously reported to accelerate hydrolysis of long-chain fatty acids in anaerobic fermentation reactors, providing low-chain molecules to methanogens for CH 4 production (Du et al, 2019) and possibly explaining the relevant presence of Methanothrix on the anode (36.4 ± 5.7%, not previously reported for similar systems). Equal considerations are valid for Levilinea (Zakaria and Dhar, 2019), which was previously reported in the anode bacterial community of microbial electrolysis cells treating waste activated sludge from municipal WWTPs (Zhao et al, 2016). Apart from Methanothrix (32.4 ± 8.4%), the cathode samples revealed the significant presence of OTU 14 and OTU 3, belonging to the genera Atopobium (Actinobacteria) and Methanobacterium (Euryarchaeota) (1.3 ± 0.01% and 0.1 ± 0.01%, respectively, p = 0.011 and p = 0.003 vs. bulk medium; p = 0.002 and p < 0.001 vs. anode).…”

“…In this regard, EMG-BES can connect electrical, wastewater and natural gas grids, reducing overall energy cost and improving its resiliency. Previous studies summarized the factors affecting the performance of bioelectrochemical CH 4 production in EMG-BES: microbial communities, cathode potential, electrode materials, among them (Zhen et al, 2018;Noori et al, 2019;Zakaria and Dhar, 2019).…”

Processes for Bioenergy and Resources Recovery from Biowaste

“…Pre-treatment of feedstock prior to anaerobic digestion has been explored and adopted in full-scale anaerobic digestion facilities [8], while further research is required for process optimization. Moreover, in recent years, amending conductive materials in digesters [7], integrating anaerobic digestion with microbial electrochemical systems has also been demonstrated to be a potential approach to overcome process kinetics and stability issues faced in conventional digesters [9]. However, most of these emerging ideas have only been demonstrated on the lab-scale.…”