Scientists Look to Nature to Cut
Greenhouse Emissions
Contact: David Bayless, (740) 593-0264, bayless@ohio.edu
Editors: A photo of David Bayless and an information graphic of
the bioreactor accompany this release and may be viewed at
www.ohiou.edu/researchnews/pix/pages/Dave_bayless_low.htm
and www.ohiou.edu/researchnews/pix/pages/Bayless_biographic_72.htm.
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ATHENS, Ohio (July 19, 2000) -- Greenhouse gas emissions are an environmental concern and a
costly problem for coal-fired power plants, which are facing tighter
federal pollution laws. But scientists at Ohio University are looking to
nature to develop a cleaner, inexpensive way of removing carbon dioxide
from smokestacks.
The researchers, supported by a new $1.07 million grant from the U.S.
Department of Energy, are studying how algae and sunlight, in a natural
process known as photosynthesis, can absorb some of the carbon dioxide
produced after coal is burned. Though other scientists have used lakes
filled with algae to absorb gas emissions, the Ohio University team has
proposed growing and harvesting the organisms directly in the exhaust gas
from power plants.
Algae is not only cheap and plentiful, but could be collected from the
power plants for use by agricultural industries, says David Bayless, an
assistant professor of mechanical engineering and lead researcher on the
project.
"We're storing carbon dioxide in organisms that exist in your backyard,"
Bayless says. "Once the algae is grown, if it can't be used as fuel or a
hydrogen source, it can be used as a fertilizer or soil stabilizer."
The process, he says, would work something like this: As the carbon
dioxide exhaust moves toward the smokestacks, it would pass through tubes
of running water, creating bicarbonates that would bubble in the water like
soda pop. The water then flows through a bioreactor that contains a series
of screens on which algae grow. "The algae basically drink the
bicarbonates," says Bayless, who also serves as associate director of the
university's Ohio Coal Research Center. "They get carbon through this
system much quicker than trying to get it out of the air."
Using a system of solar panels, satellite dishes and fiber optic cables
developed by scientists at the Oak Ridge National Laboratory, a partner in
the project, only visible sunlight would be emitted into the bioreactor,
helping the algae to use carbon dioxide for fuel -- a process known as
photosynthesis.
Once the algae grow to maturity, they fall to the bottom of the bioreactor
and are harvested for other uses, says Bayless, who is collaborating on the
project with Morgan Vis-Chiasson, an assistant professor of environmental
and plant biology who specializes in algae research, and Gregory Kremer, an
assistant professor of mechanical engineering, both at Ohio University.
Until now, the Ohio University team has tested the method on a small
scale, growing about 2 pounds of algae in a direct stream of carbon dioxide
exhaust with the aid of fluorescent lights. The new, three-year Department
of Energy grant will allow them to add the bicarbonate and sunlight systems
to the project.
Researchers will use blue-green algae collected by Montana State
University colleagues at Yellowstone National Park -- where it survives near
boiling point temperatures in hot springs, a climate similar to that of a
coal-fired power plant. But their ultimate goal is to create technology
that can use any type of algae found in abundance in the world.
"We hope to make this a process that doesn't depend on any specific
organism, to be used by any power plant," Bayless says.
No one technology can solve the carbon dioxide problem for coal-burning
power plants, Bayless stresses, but the algae-fueled bioreactor could serve
as an efficient, cost-effective part of the gas emission reduction
strategy. He estimates that an average-size plant using this technology
could process 20 percent of its carbon dioxide emissions and produce
200,000 tons or more of algae per year.
The bioreactor is one of several energy technologies being developed by
Bayless and other scientists with the university's Ohio Coal Research
Center to make Ohio coal a cleaner, more viable fuel source. In other
projects supported by the Ohio Coal Development Office, the researchers are
exploring ways to reduce toxic sulfur emissions by changing the chemical
composition of the exhaust gas, and are developing a new device that could
more efficiently collect additional heavy metal particles from the exhaust
stream.
Bayless and Kremer hold appointments in the Russ College of Engineering
and Technology. Vis-Chiasson holds an appointment in the College of Arts
and Sciences.
