Carbon capture is AEP's great hope for eliminating one of the biggest remaining environmental objections to burning coal - carbon dioxide emissions, one of the main greenhouse gases contributing to global warming.
If carbon capture works, you can expect to hear a lot more talk about "clean coal."
Charleston Daily Mail - Monday, March 31, 2008
NEW HAVEN - American Electric Power executives believe that about 18 months from now they'll be able to point to a $70 million project here for proof that carbon dioxide can be captured from a coal-fired power plant's exhaust and permanently, safely stored underground.
Carbon capture is AEP's great hope for eliminating one of the biggest remaining environmental objections to burning coal - carbon dioxide emissions, one of the main greenhouse gases contributing to global warming.
If carbon capture works, you can expect to hear a lot more talk about "clean coal."
Utilities that pulverize and burn coal to create steam that spins turbines to make electricity have already reduced many pollutants. Just last May, AEP celebrated the completion of a $533 million scrubber here that reduces sulfur dioxide emissions at the Mountaineer Plant by 98 percent.
The scrubber is the latest in a long list of multimillion-dollar engineering marvels that have been bolted onto coal-fired plants since passage of the federal 1970 Clean Air Act.
Now AEP, the French engineering company Alstom and the German utility conglomerate RWE are partnering to prove that carbon dioxide can be removed from a coal-fired plant's exhaust and made harmless. The system being installed on the Mountaineer Plant will be one of the first large-scale validations of carbon-capture technology in the world.
In 2003-04 the U.S. Department of Energy and a consortium of public and private entities spent $4.2 million to drill a 10,000-foot-deep well here and study the geologic formation under the Mountaineer Plant. Battelle Memorial Institute, the lead geological consultant, determined that the rock formation the plant is adequate for long-term storage of liquefied carbon dioxide.
Dave Hall, the AEP employee who serves as liaison between the Mountaineer Plant's employees and construction workers, said the project is currently being designed. But the outline is already taking shape.
Workers recently cut two holes in the metal duct that leads to the power plant's 1,000-foot-tall smokestack. In a few months they will start building a fiberglass pipeline that will take 2 percent of the plant's exhaust from the duct and pull it down 185 feet to what is now an empty lot.
Footers will be poured in June for a six-story plant that will be constructed on the lot, Hall said.
The new plant will separate the carbon dioxide from the exhaust. A chilled ammonia process developed by Alstom will be used to convert the carbon dioxide into a liquid. The liquid will be pumped two miles underground, where it will be permanently stored in a porous, 100- to 140-foot-thick rock formation between 7,800 and 8,400 feet below the surface. The leftover exhaust will be sent back up to the smokestack.
Although the project will only take carbon dioxide out of about 20 megawatts' worth of the 1,300-megawatt plant's exhaust, that will amount to up to 100,000 metric tons of carbon dioxide a year. The project is designed to operate for three to five years. Alstom will operate it for the first year.
Mike Hammond, project engineer for AEP New Generation in Columbus, Ohio, said the project will:
Help Alstom learn how to scale up its technology.
Give AEP experience operating a carbon capture project.
Show what the process costs. The cost of removing carbon dioxide is considered an energy loss, since the energy needed for the process is subtracted from that generated by the power plant. Alstom said research shows its technology may only cause an energy loss of 10 percent.
Prove carbon dioxide can be stored safely underground, once it is captured. Hammond said Battelle's studies show the carbon dioxide will not migrate over time off of AEP's property.
Hammond said there's a 1.7-megawatt carbon capture project currently under way at Wisconsin Electric Power Co.'s Pleasant Prairie Power Plant in Wisconsin. The 20-megawatt project here represents a significant increase in size. If it succeeds, AEP and Alstom will move on to a commercial scale-up.
AEP plans to eventually install a commercial-scale system here, on a 629-megawatt Integrated Gasification Combined Cycle power plant it wants to build next to the Mountaineer Plant.
On March 6 AEP received approval from the West Virginia Public Service Commission to build the Integrated Gasification Combined Cycle plant. The company's request for approval is pending in Virginia, where a decision is expected next month. American Electric Power's Appalachian Power subsidiary has about a half-million customers in southern West Virginia and about a half-million customers in Virginia.
Although the Integrated Gasification Combined Cycle plant would not use carbon capture when it starts up, Appalachian Power President and Chief Operating Officer Dana Waldo said it is designed to do so in the future as required by regulators.