Jonathan Woodward of the Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) has found a new method that extracts hydrogen from certain forms of sugars, such as cellulose, lactose and starch. Cellulose is the principal component of biomass and the garbage we throw away every day.
To produce hydrogen from these sources, an enzyme, cellulase, must be used to convert complex sugars that constitute cellulose into a simple sugar - glucose. Enzymes from microorganisms are then used to convert the glucose into hydrogen.
"The abundance of these complex sugars, the ability to make glucose very quickly and the clean burning of hydrogen make this technology very attractive," said Woodward, a researcher in ORNL's Chemical Technology Division. "And unlike fossil fuels, which produce various pollution-creating wastes, the only waste in burning hydrogen is water."
Woodward refers to the sugars as abundant because they are easily obtainable and easily reproduced. Cellulose, the basic building block of all plant matter, can be found in wood and paper products - even old newspapers. Glucose, the most common sugar, occurs by itself or in combination with other sugars. Lactose, a milk sugar, contains glucose and galactose, which also occurs in cheese product wastes, such as cheese whey. Galactose and xylose, another principal sugar in biomass, both allow conversion into hydrogen.
Woodward said he sees the burning of hydrogen fuel as another option to go along with the conversion of corn into ethanol. However, to make the hydrogen yield from cellulose high enough for commercial use, more research and development is necessary to reduce the costs of the catalysts used in this process, as well as to increase the rate of hydrogen production.
Since publishing this work in Nature Biotechnology in July 1996, Woodward and his research group have greatly increased the rates of hydrogen production and almost doubled the efficiency of the process.
"Ultimately, in the next century, as genetic engineering becomes more effective, we will be able to make a more abundant and cheap supply of the catalysts required to make sugar into hydrogen," Woodward said. "Also, if you can reuse the catalysts, costs will come down significantly."
The project received joint funding from DOE's Office of Energy Efficiency and Renewable Energy and the Office of Energy Research.
ORNL, one of DOE's multiprogram national research and development facilities, is managed by Lockheed Martin Energy Research Corporation.