An interesting development - Hydrogen
From
EurekaAlert:
Novel sugar-to-hydrogen technology promises transportation fuel independence
The hydrogen economy is not a futuristic concept. The U.S. Department of Energy's 2006 Advance Energy Initiative calls for competitive ethanol from plant sources by 2012 and a good selection of hydrogen-powered fuel cell vehicles by 2020.
Researchers at Virginia Tech, Oak Ridge National Laboratory (ORNL), and the University of Georgia propose using polysaccharides, or sugary carbohydrates, from biomass to directly produce low-cost hydrogen for the new hydrogen economy.
A bit more:
Using synthetic biology approaches, Zhang and colleagues Barbara R. Evans and Jonathan R. Mielenz of ORNL and Robert C. Hopkins and Michael W.W. Adams of the University of Georgia are using a combination of 13 enzymes never found together in nature to completely convert polysaccharides (C6H10O5) and water into hydrogen when and where that form of energy is needed. This "synthetic enzymatic pathway"research appears in the May 23 issue of PLoS ONE, the online, open-access journal from the Public Library of Science (www.plosone.org).
And a bit more:
Polysaccharides like starch and cellulose are used by plants for energy storage and building blocks and are very stable until exposed to enzymes. Just add enzymes to a mixture of starch and water and "the enzymes use the energy in the starch to break up water into only carbon dioxide and hydrogen,"Zhang said.
A membrane bleeds off the carbon dioxide and the hydrogen is used by the fuel cell to create electricity. Water, a product of that fuel cell process, will be recycled for the starch-water reactor. Laboratory tests confirm that it all takes place at low temperature -- about 86 degrees F -- and atmospheric pressure.
The vision is for the ingredients to be mixed in the fuel tank of your car, for instance. A car with an approximately 12-gallon tank could hold 27 kilograms (kg) of starch, which is the equivalent of 4 kg of hydrogen. The range would be more than 300 miles, Zhang estimates. One kg of starch will produce the same energy output as 1.12 kg (0.38 gallons) of gasoline.
Since hydrogen is gaseous, hydrogen storage is the largest obstacle to large-scale use of hydrogen fuel. The Department of Energy's long-term goal for hydrogen storage was 12 mass percent, or 0.12 kg of hydrogen per one kg of container or storage material, but such technology is not available, said Zhang. Using polysaccharides as the hydrogen storage carrier, the research team achieved hydrogen storage capacity as high as 14.8 mass percent, they report in the PLOS article.
The idea began as a theory. The research was based on Zhang's previous work pertaining to cellulosic ethanol production and the ORNL and University of Georgia researchers' work with enzymatic hydrogen production. UGA Distinguished Professor Adams is co-author of the first enzymatic hydrogen paper in Nature Biotechnology in 1996. The researchers were certain they could put the processes together in one pot. They tested the theory using Oak Ridge's hydrogen detectors and documented that hydrogen is produced as they predicted.
Very cool if this can be scaled up...
The original paper is here:
High-Yield Hydrogen Production from Starch and Water by a Synthetic Enzymatic Pathway
hat tip to Gary at
Muck and Mystery for the link.
Posted by DaveH at May 23, 2007 5:03 PM