American Electric Power, a major electric utility, is planning the
largest demonstration yet of capturing carbon dioxide from a coal-fired
power plant and pumping it deep underground.
Various experts consider that approach, known as sequestration,
essential to reining in climate change by preventing the gas from being
added to the atmospheric blanket that promotes global warming.
The project, to be announced Thursday by American Electric Power, based
in Columbus, Ohio, will use a new process — so far tested only at
laboratory scale — that uses chilled ammonia to absorb the gas for
collection. The process was developed by Alstom, a major manufacturer of
generating equipment, and aims to reduce the amount of energy required
to capture the carbon dioxide.
Some experts have estimated that nearly a third of a power plant’s
energy output might be needed to pull carbon dioxide from the waste
stream. Alstom hopes to hold it to 15 percent.
The cost must be kept as low as possible if the technology is to be used
on a wide scale. Congress is seen as unlikely to impose enormously
expensive restraints on emissions. And under proposals to cap emissions
nationally and let companies trade credits for extra reductions, only
the cheapest methods of reducing greenhouse gases would thrive in the
marketplace.
A report released Wednesday by researchers at the Massachusetts
Institute of Technology called for prompt work on demonstrating the
necessary sequestration technologies.
The co-chairman of that study, Ernest J. Moniz, a former assistant
secretary of energy, said the unusually large scale of the American
Electric project made it “quite relevant.”
Climate policy specialists said the project was a significant test of
the technology and also a sign that American Electric, which relies on
coal for fuel, is expecting carbon emission limits of some kind.
The initial trial, at the company’s Mountaineer plant in New Haven,
W.Va., will take a portion of the carbon dioxide from the flue, compress
it into liquid form at more than 1,000 pounds of pressure per square
inch, and inject it 9,000 feet below the earth’s surface, a technique
that experts say is not well understood but would be essential to
large-scale carbon sequestration.
The project will begin next year, the company said. A demonstration 6 to
12 times that size, which would be commercial scale, will be conducted
soon after at a plant in Oklahoma.
“This basically represents jumping ahead,” said Stuart M. Dalton,
director of generation at the Electric Power Research Institute, a
utility consortium, in Palo Alto, Calif. His organization has helped
organize a test, one-sixth the size of the West Virginia test, that is
supposed to begin this year at a coal-fired power plant in Wisconsin.
That carbon will be re-released.
Some plants use a different separation technology to capture and sell
food-grade carbon dioxide, used in making carbonated beverages.
Worldwide, there are several places where carbon dioxide is injected
into deep wells, but none are power plants.
At the Natural Resources Defense Council, an environmental group, David
G. Hawkins, a climate expert, said, “Under any plausible scenarios of
global coal use, we are going to need carbon dioxide capture and storage.”
But Mr. Hawkins and other environmentalists said that Congress should
not wait for the outcome of demonstrations like American Electric’s to
order mandatory controls on carbon emissions.
Michael G. Morris, the president, chairman and chief executive of the
utility, said in a telephone interview that sequestration would be
necessary for society but was also enlightened self-interest on the part
of his company.
The Energy Department has concentrated on a different technology,
converting coal to a gas and taking the carbon out before the gas is
burned. American Electric is also pursuing that technology, but the
chilled-ammonia method is applicable to traditional coal plants that use
pulverized coal technology, and dozens of them are on the drawing boards.
“You, me and everyone else needs to understand that the government talks
big and moves slow,” Mr. Morris said.
He said the demonstration would cost $800 million, including work to
remove conventional pollutants like soot and sulfur dioxide before
carbon separation. The company will seek federal grants and will ask
state regulators to let it charge customers.
Carbon from the larger trial at the Oklahoma plant will be sold for
injection into old oil fields where pressure and production have fallen.
(Por Matthew L. Wald,
The N.Y.Times, 15/03/2007)