Monday, May 21, 2007

New Biofuel From Trees Developed


Science Daily — A team of University of Georgia researchers has
developed a new biofuel derived from wood chips. Unlike previous fuels
derived from wood, the new and still unnamed fuel can be blended with
biodiesel and petroleum diesel to power conventional engines.

"The exciting thing about our method is that it is very easy to do,"
said Tom Adams, director of the UGA Faculty of Engineering outreach
service. "We expect to reduce the price of producing fuels from biomass
dramatically with this technique."

Adams, whose findings are detailed in the early online edition of the
American Chemical Society journal Energy and Fuels, explained that
scientists have long been able to derive oils from wood, but they had
been unable to process it effectively or inexpensively so that it can be
used in conventional engines. The researchers have developed a new
chemical process, which they are working to patent, that inexpensively
treats the oil so that it can be used in unmodified diesel engines or
blended with biodiesel and petroleum diesel.

Here's how the process works: Wood chips and pellets – roughly a quarter
inch in diameter and six-tenths of an inch long – are heated in the
absence of oxygen at a high temperature, a process known as pyrolysis.
Up to a third of the dry weight of the wood becomes charcoal, while the
rest becomes a gas. Most of this gas is condensed into a liquid bio-oil
and chemically treated. When the process is complete, about 34 percent
of the bio-oil (or 15 to 17 percent of the dry weight of the wood) can
be used to power engines. The researchers are currently working to
improve the process to derive even more oil from the wood.

"This research will really benefit the citizens of the state, and that
fits perfectly into the mission of a land grant institution," Adams
said. "Georgia has 24 million acres of forested land, and we could see
increased employment and tax revenues based on this research. Another
huge benefit is that this fuel would reduce the amount of fuel we import
from other states and from other countries."

Adams pointed out that the new biofuel also offers environmental
benefits. The fuel is nearly carbon neutral, meaning that it does not
significantly increase heat-trapping carbon dioxide in the atmosphere as
long as new trees are planted to replace the ones used to create the fuel.

The researchers have also set up test plots in Tifton, Ga., to explore
whether the charcoal that is produced when the fuel is made can be used
as a fertilizer. Adams said that if the economics work for the charcoal
fertilizer, the biofuel would actually be carbon negative.

"You're taking carbon out of the atmosphere when you grow a plant, and
if you don't use all of that carbon and return some of it to the soil in
an inert form, you're actually decreasing the amount of carbon dioxide
in the atmosphere," Adams explained. "We're optimistic because in most
types of soil, carbon char has very beneficial effects on the ecology of
the soil, its productivity and its ability to maintain fertility."

Although the new biofuel has performed well, Adams said further tests
are needed to assess its long-term impact on engines, its emissions
characteristics and the best way to transport and store it.

"It's going to take a while before this fuel is widely available," Adams
said. "We've just started on developing a new technology that has a lot
of promise."

The research was funded by the U.S. Department of Energy, the Georgia
Traditional Industries Pulp and Paper Research Program and the State of
Georgia upon the recommendation of the Governor's Agriculture Advisory

Note: This story has been adapted from a news release issued by
University of Georgia.

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