Monday, February 16, 2009

Growth Spurts: Enzyme Cocktail Converts Woodchips and Grass Into Hydrogen Fuel

Researchers at Virginia Tech, Oak Ridge National Laboratory, and the University of Georgia have produced hydrogen gas pure enough to power fuel cells by mixing 14 enzymes, one coenzyme, and cellulosic materials like woodchips or grass.

The group announced three advances from their "one pot" process: 1) a novel combination of enzymes, 2) an increased hydrogen generation rate -- to as fast as natural hydrogen fermentation, and 3) a chemical energy output greater than the chemical energy stored in sugars – the highest hydrogen yield previously reported from cellulosic materials.

"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.

The researchers used cellulosic materials isolated from wood chips, but crop waste or switchgrass could also be used. Using cellulose instead of starch expands the renewable resource for producing hydrogen to include biomass.

"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.

The research results have been published in the Wiley journal ChemSusChem (Chemistry and Sustainability), in an article titled "Spontaneous High-Yield Production of Hydrogen from Cellulosic Materials and Water Catalyzed by Enzyme Cocktails."

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