Table 1. Methanogenesis pathways

Pathways Reactions References
Hydrogenotrophic pathway CO2 + 4H2 → CH4 + 2H2O [57,58,87,89]
Methylotrophic pathway CH3OH + H2 → CH4 + H2O4CH3OH → 3CH4 + CO2 + 2H2OCH3NH2 + H2 → CH4 + NH3 [98,121]
CO2, carbon dioxide; H2, hydrogen; CH4, methane; H2O, water; CH3OH, methanol; CH3NH2, methylamine.