A new lab study in Results in Engineering tested a dual-electrode microbial electrosynthesis reactor that pairs a gas-diffusion cathode fed with CO2 and a glycerol-fed bioanode. The gas-fed cathode outperformed a bicarbonate-fed setup, producing up to 5.89 grams of acetate per liter and reaching a current density of minus 1,703 milliamperes per square meter by the third cycle. The glycerol-fed bioanode also shifted from acetate to propionate as the main product over time. The authors note the work is an operational comparison, not proof of mechanism: carbon loading was not matched, no isotope tracing was used, and only single reactors ran per condition. Gas-diffusion electrodes also face flooding and salt buildup in long runs. Still, the design points toward using CO2 and biodiesel byproduct glycerol as feedstocks for chemical production, even if microbial electrosynthesis remains far from industrial scale.
