SUNY researchers find way to make ethanol from wood
By WILLIAM KATES
Associated Press Writer
January 13, 2005, 4:04 PM EST
SYRACUSE, N.Y. Using nothing more than water, State University of New York researchers have devised a method for removing energy-rich sugars from wood that can be used to produce ethanol.
The process is still a year or two away from commercial application, but researchers at SUNY's College of Environmental Science and Forestry and industry officials said they are encouraged it will prove economical on a larger scale.
If successful, the process will be a boost to both New York's fledgling ethanol industry, and profitable for pulp and paper makers, said Dr. Thomas Amidon, chair of ESF's Paper Science and Engineering faculty.
"The process is a natural fit for New York, which has more than 18 million acres of mostly hardwood forests," Amidon said.
Hardwoodswhich contain about four times as much sugar as softwood treesalso cover most of the Northeast and central Atlantic states.
"This area of cellulosic ethanol is very promising," said Monte Shaw, a spokesman for the Renewable Fuels Association, a national trade group for the U.S. ethanol fuel industry.
"There are a lot of different ideas out there on how to get to the cellulose (sugar). We just need one breakthrough," Shaw said.
Ethanol is an additive blended with gasoline to reduce auto emissions and increase its octane levels. Its use has exploded since 2004, when the federal government banned the use of the toxic chemical called MTBE (methyl tertiary butyl ether) to enhance the cleaner burning of fuel. About 3.6 billion gallons of ethanol were produced last year in the United States, according to the RFA.
Typically, ethanol is made from corn, but scientists have been exploring the use of other crops, as well as grasses and trees.
Amidon said wood has several advantages over corn.
"Trees can be harvested year round so you don't have to stockpile large inventories. They are more efficient energy collectors than annual crops. And, trees can be shipped more economically," he said.
There also is a secondary benefit. The separation process also produces acetic acid, which is used primarily in manufacturing polyvinyl acetate, a plastic. The commercial value of acetic acid is nearly three times that of ethanol, Amidon said.
ESF researchers used sugar maples, the state's most common tree, but the process is not choosy about the kind of hardwoods used, said Amidon. The college has a 1,000-acre willow plantation and has been experimenting with the fast-growing shrub as another source of ethanol, as well as a biofuel.
The work, while still in its testing phases, has received support from International Paper, the world's largest paper company. Michael Brower, the college's director of governmental relations, said International Paper has agreed to try the process at its Ticonderoga plant.
"The concept of biorefineries has a very promising future that we need to explore further," said Dr. Gopaul Goyal, an International Paper scientist who is a director on the board of the Empire State Paper Research Association, which provides funding for such projects.
Brower noted that paper makers already have most of the equipment they would need to extract the sugar from the wood. Currently, paper plants discard the sugar-rich water used in making pulp, he said.
Empire Biofuels and Northeast Biofuels, the developers of New York's two proposed ethanol plants, also are keenly interested in the process, Brower said.
The process involves using ordinary wood chips, which are mixed with water and heated at temperatures between 140 degrees and 180 degrees centigrade for a specified time.
The watery solution that remains after the chips are removed is then filtered through a membrane that separates the sugars and acetic acid from the water. The sugars are then fermented to produced ethanol. "Water is the solvent we use ... if it gets loose in the world, it's just water," Amidon said.
After the desired components are extracted, the residue can be burned or gasified for combined heat and power uses, he said.
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