Electromethanogenesis is a form of electrofuel production where methane is produced by direct biological conversion of electrical current and carbon dioxide.
Methane producing technologies garnered interest from the scientific community prior to 2000, but electromethanogenesis did not become a significant area of interest until 2008. Publications concerning catalytic methanation have increased from 44 to over 130 since 2008. Electromethanogenesis has drawn more research due to its proposed applications. The production of methane from electrical current may provide an approach to renewable energy storage. Electrical current produced from renewable energy sources may, through electromethanogenesis, be converted into methane which may then be used as a biofuel. It may also be a useful method for the capture of carbon dioxide which may be used for air purification.
In nature, methane formation occurs biotically and abiotically. Abiogenic methane is produced on a smaller scale and the required chemical reactions do not necessitate organic materials. Biogenic methane is produced in anaerobic natural environments where methane forms as the result of the breakdown of organic materials by microbes—or microorganisms. Researchers have found that the biogenic methane production process can be replicated in a laboratory environment through electromethanogenesis. The reduction of CO in electromethanogenesis is facilitated by an electrical current at a biocathode in a microbial electrolysis cell (MEC) and with the help of microbes and electrons (Equation 1) or abiotically produced hydrogen (Equation 2).
(1) CO + 8H + 8e ↔ CH + 2HO
(2) CO + 4H ↔ CH + 2HO