(138e) CO2 Conversion to Fuels and Chemicals through Microbial Electrolysis Cells

With a fully oxidized carbon atom, CO₂ is notoriously stable under most environmental conditions. Thus, the conversion of CO₂ to fuels and chemicals has been pursued through chemical, photochemical, electrochemical, and biological means, in addition to reforming. Through these different routes, CO₂ can be converted to chemicals such as formic acid, acetic acid, and urea; alcohols such as ethanol and methanol; and gases such as methane, syngas (CO), and acetylene (C₂H₂). The majority of these reactions require a reducing agent, most commonly hydrogen (H₂). However, hydrogen is quite expensive, so the resulting products would not be cost-competitive; thus, the need for alternative approaches is obvious.

To reduce CO₂ to fuels and chemicals, our laboratory has enriched a microbial community that has demonstrated repeatable high rate production of methane and organic acids from CO₂. Two unique features make this process extremely interesting for further exploration, and profoundly attractive for potential technological development. First, CO₂ conversion to value-added products takes place in a one-chamber membrane-less Microbial Electrolysis Cell (MEC). The methane production rate is 10-56x higher than typically reported for methane release from CO₂ in two-chamber MEC units. Second, the enriched microbial community thrives on a defined medium without the presence of any organic carbon and nitrogen sources.

In this talk, we will present our recent data on this project. Results, such as the microbial community composition, the enrichment process, electrode modification and fundamentals related to the single chamber MECs will be discussed. All of these will assist in future research and development in making MEC a promising platform for converting CO₂ to useful commodities.