Researchers at Virginia Tech University have discovered a way to derive large quantities of hydrogen from any plant, a technology breakthrough that could not only greatly lower the cost of hydrogen fuel cells, but also lower the carbon footprint of hydrogen extraction.
The key to this discovery is xylose, the most abundant simple plant sugar. The researchers found a way to use xylose to produce hydrogen, something that had previously only been considered in theory. Because xylose comprises as much as 30 percent of plant cell walls, this new process can attain hydrogen from any type of biomass.
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 energy stored in xylose splits water molecules, yielding high-purity hydrogen that can be directly utilized by proton-exchange membrane fuel cells.
The university notes that the real amazing part is that it can be done at low temperatures, generating more hydrogen energy than the chemical energy stored in the xylose and polyphosphate and creating an energy efficiency of more than 100 percent -- a net gain. This means that low temperature waste heat from other processes could be used to produce hydrogen using this method, making it even more environmentally-friendly.
When hydrogen is produced from natural gas, it creates a large amount of carbon emissions, so while the hydrogen fuel itself is a clean energy source, the method by which it is derived is often not.
“It really doesn’t make sense to use non-renewable natural resources to produce hydrogen,” lead researcher Y.H. Percival Zhang, an associate professor of biological systems engineering said. “We think this discovery is a game-changer in the world of alternative energy.”