Energy project puts focus on new emission control

Portland Press Herald

Scientists consider the prospects for carbon capture and storage at the proposed Twin River plant.

By JOHN RICHARDSON Staff Writer October 25, 2007

http://pressherald.mainetoday.com/story.php?id=142808&ac=PHbiz

WISCASSET — Maine and other states want to slow global
warming by setting limits on carbon dioxide that comes from
the smokestacks of large power plants.

But what if the gas could be captured before it gets into the
atmosphere, then injected deep into the earth?

The huge potential of that technology -- known as carbon
capture and storage -- is driving scientific research around the
world. Now, a proposed coal gasification plant in Wiscasset has
focused attention on whether, and how soon, it can be done in
Maine.

"This is clearly going to be an issue of statewide discussion,"
said David Littell, commissioner of the Maine Department of
Environmental Protection.

Scientists from around the Northeast gathered at the Chewonki
Foundation on Wednesday to present the latest research on
carbon storage, which involves injecting carbon dioxide into
deep underground aquifers that can absorb and hold it.

Large-scale carbon storage is possible and is being tested
elsewhere in the country, the researchers said. But it's expensive
and it will take years of geological studies to determine whether
it's even possible in New England, they said.

Chewonki's forum drew more than 100 Mainers who are
concerned about global warming, the coal plant or both.

The $1.5 billion Twin River Energy Center, proposed near the
former site of the Maine Yankee nuclear power plant, would turn
coal and wood waste into a synthetic gas. Some of the gas would
be burned to make electricity and some would be converted into
a diesel fuel.

Twin River faces years of study and review by local and state
regulators. And it will be put to an early test on Nov. 6, when
Wiscasset voters decide whether to let the developer exceed a
height limit in the zoning rules.

Maine's Legislature also is expected to weigh in on the plant.

State Rep. W. Bruce MacDonald, D-Boothbay, said Wednesday
that he has submitted legislation to ban any new coal plants in
Maine unless they can capture and store 90 percent of their
carbon dioxide emissions. Passage of the bill as written could
kill the plan in Wiscasset.

Coal is considered a major culprit behind global warming
because it puts more carbon dioxide, a heat-trapping gas, into
the atmosphere than other fossil fuels.

Twin River's gasification technology is different from that of
conventional plants because it could more easily capture the
gas, and potentially store it.

If it can store 25 percent of the carbon dioxide it generates,
Twin River could have about the same impact on global warming
as if it used natural gas and oil instead of coal, according to a
study that the developer released at Wednesday's forum. It's
unclear where the carbon dioxide would be stored, however.

"We have not characterized the geologic sinks in this area, and
that's going to take some time," said Sarah Forbes, an
engineering consultant hired by Twin River to lead the study.
Carbon dioxide may have to be piped hundreds of miles, for
burial in other parts of the country or beneath the ocean, she
said.

Researchers said Wednesday that Maine's granite foundations
make it unlikely that there are porous formations to hold carbon
dioxide. There could be such formations beneath the Gulf of
Maine, they said.

"We do know there are some potential sites there," said Howard
Herzog of the Massachusetts Institute of Technology, an expert
on carbon storage. "We don't really have any holes in the ground
to give us data."

Building long pipelines to carry the carbon dioxide elsewhere is
an alternative, but would be too expensive, Herzog said.

Developing the ability to capture and store carbon is considered
an urgent need globally. The United States gets half of its power
from coal and has vast reserves of the mineral, and China is
firing up massive coal-burning power plants at a rate of about
one a week, with no effort to capture the carbon dioxide.

New England has not been a big coal-burning region and, unlike
the rest of the country, it has not been studied for potential
underground carbon storage sites. Although gas-fired power
plants may ultimately be required to capture the gas, too,
carbon dioxide storage has emerged as an issue here only since
Twin River's arrival this summer.

"It would be very prudent for New England to start thinking
about it," said Joe Chaisson, research and technical director for
Clean Air Task Force, an environmental advocacy group. "It's
gotten people thinking."



Staff Writer John Richardson can be contacted at 791-6324 or at:

jrichardson@pressherald.com

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