A new breakthrough has been announced in biofuel production that could mean cheap clean hydrogen energy is just around the corner. The new process has been able to produce hydrogen from simple plant sugars, something previously only theoretically possible.
The new process is cheap and does not use polluting and energy intensive processes to do the conversion. There is almost zero greenhouse gasses and the new process can be used on almost any type of biomass. Scaled up the new process could become an integral source of cheap and clean sustainable energy.
The process was developed by a team of researchers at Virginia Tech and has just been published as a staring paper in the chemistry journal Angewandte Chemie, International Edition.
“Our new process could help end our dependence on fossil fuels,” said Y.H. Percival Zhang, an associate professor of biological systems engineering in the College of Agriculture and Life Sciences and the College of Engineering “Hydrogen is one of the most important biofuels of the future.”
Zhang and his team have succeeded in using xylose, the most abundant simple plant sugar, to produce a large quantity of hydrogen that previously was attainable only in theory. Zhang’s method can be performed using any source of biomass.
Jonathan R. Mielenz, group leader of the bioscience and technology biosciences division at the Oak Ridge National Laboratory, who is familiar with Zhang’s work but not affiliated with this project, said this discovery has the potential to have a major impact on alternative energy production.
“The key to this exciting development is that Zhang is using the second most prevalent sugar in plants to produce this hydrogen,” he said. “This amounts to a significant additional benefit to hydrogen production and it reduces the overall cost of producing hydrogen from biomass.”
The new process could be on the marketplace in as little as 3 years and adds the potential for cheap sustainable energy that is reliable and available on tap. Zhang said when it does become commercially available, it has the possibility of making an enormous impact. “The potential for profit and environmental benefits are why so many automobile, oil, and energy companies are working on hydrogen fuel cell vehicles as the transportation of the future,” Zhang said. “Many people believe we will enter the hydrogen economy soon, with a market capacity of at least $1 trillion in the United States alone.”
The major obstacles to hydrogen as a fuel has been the cost of production, the environmental impacts of resources used to release hydrogen and the low quality of the hydrogen that is captured. Zhangs process though uses nature itself through enzymes to release the hydrogen.
For seven years, Zhang’s team has been focused on finding non-traditional ways to produce high-yield hydrogen at low cost, specifically researching enzyme combinations, discovering novel enzymes, and engineering enzymes with desirable properties. [pullquote]It really doesn’t make sense to use non-renewable natural resources to produce hydrogen. We think this discovery is a game-changer in the world of alternative energy.[/pullquote]
The team liberates the high-purity hydrogen under mild reaction conditions at 122 degree Fahrenheit and normal atmospheric pressure. The biocatalysts used to release the hydrogen are a group of enzymes artificially isolated from different microorganisms that thrive at extreme temperatures, some of which could grow at around the boiling point of water.
The researchers chose to use xylose, which comprises as much as 30 percent of plant cell walls. Despite its abundance, the use of xylose for releasing hydrogen has been limited. The natural or engineered microorganisms that most scientists use in their experiments cannot produce hydrogen in high yield because these microorganisms grow and reproduce instead of splitting water molecules to yield pure hydrogen.
To liberate the hydrogen, Virginia Tech scientists separated a number of enzymes from their native microorganisms to create a customized enzyme cocktail that does not occur in nature. The enzymes, when combined with xylose and a polyphosphate, liberate the unprecedentedly high volume of hydrogen from xylose, resulting in the production of about three times as much hydrogen as other hydrogen-producing microorganisms.
The commercial market for hydrogen gas is now around $100 billion for hydrogen produced from natural gas, which is expensive to manufacture and generates a large amount of the greenhouse gas carbon dioxide. Industry most often uses hydrogen to manufacture ammonia for fertilizers and to refine petrochemicals, but an inexpensive, plentiful green hydrogen source can rapidly change that market.
“It really doesn’t make sense to use non-renewable natural resources to produce hydrogen,” Zhang said. “We think this discovery is a game-changer in the world of alternative energy.”
Angewandte Chemie, International Edition: High-Yield Production of Dihydrogen from Xylose by Using a Synthetic Enzyme Cascade in a Cell-Free System.