Using a new electrically-assisted microbial fuel cell (MFC) that does not require oxygen, researchers at Penn State and Ion Power Inc. have developed the first process that enables bacteria to coax four times as much hydrogen directly out of biomass than can be generated typically by fermentation alone.

“This form of renewable energy production may help offset the substantial costs of wastewater treatment as well as provide a contribution to nations able to harness hydrogen as an energy source,” according to Dr. Bruce Logan, Penn State professor of environmental engineering and inventor of the MFC.

“This new process demonstrates, for the first time, that there is real potential to capture hydrogen for fuel from renewable sources for clean transportation.”

Hydrogen production by bacterial fermentation is currently limited by the “fermentation barrier” — the fact that bacteria, without a power boost, can only convert carbohydrates to a limited amount of hydrogen and a mixture of “dead end” fermentation end products such as acetic and butyric acids.

However, giving the bacteria a small assist with a tiny amount of electricity — about 0.25 volts — they can leap over the fermentation barrier and convert a “dead end” fermentation product, acetic acid, into carbon dioxide and hydrogen.

Penn State news release