Hydrogen silver bullet?

Engineers at the University of Pennsylvania have reportedly produced 288% more energy in creating a hydrogen fuel than was used in the process, a massive improvement over previous efforts. (Hat tip to this dailyKos diary).

Numerous public transportation systems are moving toward hydrogen-powered engines as an alternative to gasoline, but most hydrogen today is generated from nonrenewable fossil fuels such as natural gas.

The method used by engineers at Pennsylvania State University however combines electron-generating bacteria and a small electrical charge in a microbial fuel cell to produce hydrogen gas….

In the past, the process, which is known as electrohydrogenesis, has had poor efficiency rates and low hydrogen yields.

But the researchers at Pennsylvania State University were able to get around these problems by chemically modifying elements of the reactor.

In laboratory experiments, their reactor generated hydrogen gas at nearly 99 percent of the theoretical maximum yield using aetic acid, a common dead-end product of glucose fermentation.

We’ve long heard about the future hydrogen highway, where transportation vehicles are fueled by liquid hydrogen and emit only water. This is the so-called dream zero emission fuel but the dream has been hampered by a lack of a renewable energy source, poor conversion rates, storage issues and the massive investment in infrastructure required in this new fuel scenario. But this finding could radically change all that.

Let’s do a quick comparison of different fuel sources to see why:

  • Corn ethanol (currently used in the U.S.): for every 1 unit of energy that goes in to creating corn-based ethanol, you get 1.3 units of energy out.
  • Sugarcane ethanol (currently used in Brazil): 8 units out for every 1 in.
  • Biodiesel: 2.5 units.
  • Cellulosic ethanol (not yet production ready): estimated between 2 and 36 units out for every 1 unit of energy in, depending upon the production method.
  • Microbial fuel cells: 2.9 units of energy created for every unit of energy used.

See this National Geographic interactive on biofuels to learn more. While cellulosic ethanol may have a greater promise for energy output, microbial hydrogen gas may be a more immediate solution:

The technology offers a way to cheaply and efficiently generate hydrogen gas from readily available and renewable biomass such as cellulose or glucose, and could be used for powering vehicles, making fertilizer and treating drinking water.

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