11-04-2008: Chemists are describing development of a "revolutionary" process for converting plant sugars into hydrogen, which could be used to cheaply and efficiently power vehicles equipped with hydrogen fuel cells without producing any pollutants. The process involves combining plant sugars, water, and a cocktail of powerful enzymes to produce hydrogen and carbon dioxide under mild reaction conditions. They reported on the system, described as the world's most efficient method for producing hydrogen, at the 235th national meeting of the American Chemical Society.
The new system helps solve the three major technical barriers to the so-called "hydrogen economy," researchers said. Those roadblocks involve how to produce low-cost sustainable hydrogen, how to store hydrogen, and how to distribute it efficiently, the researchers say.
"This is revolutionary work," says lead researcher Y.-H. Percival Zhang, Ph.D., a biochemical engineer at Virginia Tech in Blacksburg, Va. "This has opened up a whole new direction in hydrogen research. With technology improvement, sugar-powered vehicles could come true eventually."
Zhang and colleagues believe they have found the most promising hydrogen-producing system to date from plant biomass. The researchers also believe they can produce hydrogen from cellulose, which has a similar chemical formula to starch but is far more difficult to break down. In laboratory studies, the scientists collected 13 different, well-known enzymes and combined them with water and starches. Inside a specially designed reactor and under mild conditions (approximately 86 degrees Fahrenheit), the resulting broth reacted to produce only carbon dioxide and hydrogen with no leftover pollutants.
The method, called "in vitro synthetic biology," produced three times more hydrogen than the theoretical yield of anaerobic fermentation methods. However, the amount of hydrogen produced was still too low for commercial use and the speed of the reactions isn't optimal, Zhang notes.
The researchers are now working on making the system faster and more efficient. One approach includes looking for enzymes that work at higher temperatures, which would speed hydrogen production rates. The researchers also hope to produce hydrogen from cellulose, which has similar chemical formula to starch, by replacing several enzymes in the enzyme cocktail.
This is where you can add this news to your personal favourites
New technology offers the promise of reducing billions of dollars of losses that occur each year from the silent, invisible killer of fruits, vegetables and cut flowers — a gas whose effects are familiar to everyone who has seen bananas and other fruit ripen too quickly and rot. That's the ... more
In an advance toward solving a 50-year-old mystery, scientists are reporting new evidence on how the fluoride in drinking water, toothpastes, mouth rinses and other oral-care products prevents tooth decay. Their report appears in the ACS journal Langumir.Karin Jacobs and colleagues explain ... more
Scientists reported a discovery that could speed an emerging effort to replace ethanol in gasoline with a substantially better fuel additive called butanol, which some experts regard as "the gasoline of the future."
Duncan Wass explained that ethanol has become a leading biofuel — millions ... more
If the current national challenge to make solar energy cost competitive with other forms of energy by the end of this decade is met, Ranga Pitchumani, the John R. Jones III Professor of Mechanical Engineering at Virginia Tech, will have played a significant role in the process.
U.S. Secreta ... more
A team of Virginia Tech researchers has discovered a way to extract large quantities of hydrogen from any plant, a breakthrough that has the potential to bring a low-cost, environmentally friendly fuel source to the world.
"Our new process could help end our dependence on fossil fuels," sai ... more
An international research team has described the first calculations of Raman optical activity (ROA) spectra using coupled-cluster theory – one of the most reliable quantum chemical methods available. ROA is a valuable tool for the structural characterization of a wide range of molecules, in ... more