Enhancement of carbon dioxide reduction and methane production by an obligate anaerobe and gas dissolution device

• The potential of CH4 production by anaerobic fermentor feeding with H2 and CO2 was investigated.
• The solubility of H2–CO2 mixed gas (particularly that of H2) using a gas dissolution device increased.
• This system has the potential to reduce CO2 emissions and generate methane.

The use of gas dissolution devices to improve the efficiency of H2 dissolution has enhanced CO2 reduction and CH4 production. In addition, the nutrients that initially existed in anaerobic sludge were exhausted over time, and the activities of anaerobic microorganisms declined. When nutrients were artificially injected, CO2 reduction and CH4 production rates climbed. Thus, assuming that the activity of the obligatory anaerobic microorganisms is maintained, a gas dissolution device will further enhance the efficiency of CO2 reduction and CH4 production.