'One Pot' cocktail of enzymes produces hydrogen from cellulose

February 12 2009 / by Garry Golden
Category: Energy   Year: Beyond   Rating: 2

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Our economy grows because it captures stored energy released from the chemical bonds in fossil fuels formed by ancient plants and microbes that became coal and oil.

Our power plants produce electricity by breaking up carbon-hydrogen chains from coal and natural gas, and our cars blow up ancient microbes that we call 'oil'.

The value of a 'fuel' is based on its hydrogen to carbon ratio.  The more hydrogen, the cleaner and better the fuel.

Yes, it's confusing, but also very important for everyone to understand where we 'extract' energy from: chemical bonds.

An Era of Clean Electrons, Clean Molecules
In addition to generating electricity via renewables (et al), a central piece of our 21st century energy strategy is to reduce the amount of carbon and increase the percentage of hydrogen to hydrogen bonds (e.g. 'Cleaner molecules' that store energy) that drive our economy.

One alternative to fossil fuels, is the use of biomass waste materials that contain hydrogen molecules that can be freed (via biological enzymes) to be used in fuel cells to produce electricity.

An Elegant One Pot' Solution
Researchers at Virginia Tech, Oak Ridge National Laboratory (ORNL), and the University of Georgia have produced hydrogen gas by mixing 14 enzymes, one coenzyme, cellulosic materials from nonfood sources, and water heated to about 90 degrees (32 C).

The researchers' novel combination of enzymes could equal natural hydrogen fermentation, and a chemical energy output greater than the chemical energy stored in sugars – the highest hydrogen yield reported from cellulosic materials.

Low Temperature: 'Prometheus Stealing Fire" (Continue)

"In addition to converting the chemical energy from the sugar, the process also converts the low-temperature thermal energy into high-quality hydrogen energy – like Prometheus stealing fire," said Percival Zhang, assistant professor of biological systems engineering at Virginia Tech.

"It is exciting because using cellulose instead of starch expands the renewable resource for producing hydrogen to include biomass," said Jonathan Mielenz, leader of the Bioconversion Science and Technology Group at ORNL.

The researchers used cellulosic materials isolated from wood chips, but crop waste or switchgrass could also be used. "If a small fraction – 2 or 3 percent – of yearly biomass production were used for sugar-to-hydrogen fuel cells for transportation, we could reach transportation fuel independence," Zhang said. (He added that the 3 percent figure is for global transportation needs. The U.S. would actually need to convert about 10 percent of biomass – which would be 1.3 billion tons of usable biomass)

Eureka Press Release

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