Monday, December 10, 2007

With A Little Help From Our Friends


With the advent of global warming, the pursuit for the technology to replace petroleum-powered engines is at the forefront of environmental research. Among the frontrunners is the hydrogen fuel cell. Hydrogen, the most abundant element in the universe, is used to produce electrical energy with the only emission being warm water. While this seems like a highly promising alternative, the cost, and the pollution created by producing the needed molecular hydrogen (H2) does not solve the problems associated with fossil fuel burning engines. If H2 could be generated cheaply, without creating pollution, mass-produced clean running vehicles could be one step closer to reality. Currently, research is being developed to employ bacteria for the production of H2.

Cyanobacteria, formerly known as blue-green algae, obtain their energy through photosynthesis, where light energy is converted to biochemical energy by a photochemical reaction, and CO2 is reduced to organic compounds. However, under certain conditions, instead of reducing CO2, cyanobacteria consume biochemical energy to produce H2, with the service of the enzymes hydrogenase and nitrogenase. A newly acquired process uses the consumption of wastewater and other biomass by bacteria to produce four times more H2 than previous efforts. While the bacteria produce H2 by themselves, the fermentation process has a limit. When the bacteria are jolted with a small amount of electricity, approximately 0.25 volts, the bacteria are then able to break down acetic acid into CO2 and H2, a step they were unable to make on their own. "Basically, we use the same microbial fuel cell we developed to clean wastewater and produce electricity. However, to produce hydrogen, we keep oxygen out of the microbial fuel cell and add a small amount of power into the system.” said Penn State Professor Bruce Logan. “The technique, in theory, could obtain hydrogen from any biodegradable, dissolved, organic matter, including human, agricultural or industrial wastewater while simultaneously cleaning the wastewater.”

While this research is a hopeful idea to generate H2 cheaply and without environmental impact, it is still in its preliminary stages. Nevertheless, the idea of being able to employ bacteria to help with the campaign against global warming is fascinating. It is amazing think that something as tiny as bacteria could be a part of the resolution to something as big as global warming.

References

http://www.planetark.com/dailynewsstory.cfm/newsid/45296/story.htm

http://www.theregister.co.uk/2005/04/26/bacteria_hydrogen_production/

http://www.livescience.com/technology/050426_hydrogen_waste.html

http://www.sciencedaily.com/releases/2003/05/030521092358.htm

http://www.fao.org/docrep/w7241e/w7241e0g.htm

http://en.wikipedia.org/wiki/Fuel_cell

http://en.wikipedia.org/wiki/Cyanobacteria

1 comment:

Dominic B. said...

Bacteria to our rescue? Maybe! My question...are we (humans) wise enough to harvest this power without destroying everything else? Not so sure!