Cars that run on hydrogen made from starch
According to an article published this week in Technology Review, using a cooking of selected enzymes from various organisms, a group of researchers has developed a new method to convert starch from various sources into hydrogen gas, at low pressure and temperature, including: found in corn or potatoes. This new method produces three times more hydrogen than the old enzymatic method, which indicates that it could be useful to supply hydrogen to vehicles that run on this fuel.
Researchers at Virginia Tech in Blacksburg, Oak Ridge National Laboratory and the University of Georgia combined 13 commercially available enzymes isolated from rabbit yeast, bacteria, spinach and muscle. The work has been published online in PLoS ONE, a journal edited by the Public Library of Science. Hydrogen comes from two sources: starch and the water used to oxidize it. According to Y. Percival Zhang, professor of biological systems at Virginia Tech, enzymes promote chemical reactions in which water and starch are completely converted to hydrogen and carbon dioxide.
The new system produces more hydrogen than previous experimental systems that converted sugars into hydrogen, but the rate at which the gas is produced is extremely low. According to Zhang, this is partly because the researchers used the enzymes they had on hand and did not optimize the system. The next project will include a detailed analysis of each stage of the process to identify the steps that limit speed.
For example, one of the enzymes may be creating a by-product that slows down subsequent steps, says Michael Adams, a professor of biochemistry and molecular biology at the University of Georgia. The researchers will therefore try other enzymes or modify the current ones to minimize the formation of by-products. They will also look for enzymes that can work at higher temperatures in order to increase the rate of production.
According to Zhang, one of the first applications of the system could be to generate hydrogen for fuel cells in portable electronic devices. Starch may be a safer way to store energy than methanol, the current option for these devices. However, he estimates that it will take six to eight years to sufficiently improve the production speed for these applications. Lastly, he hopes his system will solve one of the biggest problems with hydrogen-powered vehicles: getting enough hydrogen in the tank to compete with gasoline vehicles.
Source: Technology Review