Researchers at Penn State have discovered a process for generating hydrogen from the decomposition of a common acid, according to a study published in the Proceedings of the National Academy of Sciences.

Researchers placed naturally occurring bacteria into acetic acid, which is produced when glucose or cellulose ferment. Acetic acid is the primary component in vinegar.

The researchers added a granulated graphite anode and a cathode of carbon with a platinum catalyst, converting the entire system into a fuel cell. As a consequence of the bacteria’s digestion of the acetic acid, electrons flowed from the anode to the cathode, generating up to 0.3 volts of electricity.

With a total of 0.5 volts of energy – meaning that 0.2 volts must be added from an external source – the liquid starts to break into its component parts and hydrogen gas is released.

According to researcher Bruce E. Logan, the new process highlights that hydrogen production for energy purposes is more achievable and nearer to realization than biofuels such as ethanol.

“The energy focus is currently on ethanol as a fuel, but economical ethanol from cellulose is 10 years down the road,” Logan said. “First you need to break cellulose down to sugars and then bacteria can convert them to ethanol.”

In contrast, the fuel cell developed by Logan’s research team uses minimal processing to produce an energy surplus.

“This process produces 288 percent more energy in hydrogen than the electrical energy that is added to the process,” Logan said. If the cell is set up to siphon off some of the hydrogen that it produces in order to power its own process, the cell produces 144 percent more energy than it uses.

Fuel cells last until the fuel that powers them (in this case, acetic acid) is consumed. In contrast to batteries, in which the anode and cathode are consumed and must be replaced, the fuel cell can be recharged with fuel and continue operating.