This is an excerpt from EERE Network News, a weekly electronic newsletter.

November 04, 2009

AEP and Alstrom to Trap Carbon Dioxide Emissions from a Coal Plant

While energy efficiency and renewable energy are key technologies for moving toward a low-carbon energy future, efforts are also underway to reduce or eliminate carbon dioxide emissions from coal-fired power plants. The technology is generally called carbon capture and storage, or CCS, and the latest project to advance that technology was commissioned in late October at the Mountaineer Plant in West Virginia, owned by American Electric Power (AEP). Touted as the world's first facility to both capture and store carbon dioxide, the Mountaineer CCS demonstration project diverts a portion of the plant's exhaust through a device from Alstrom that chills the gas and combines it with an ammonium carbonate solution.

The carbon dioxide is absorbed by the ammonium carbonate solution, creating ammonium bicarbonate, which is then pressurized and heated separately to generate a pure stream of carbon dioxide. That carbon dioxide is then compressed and stored for later injection into geologic formations located 1.5 miles below ground. Although the demonstration project will provide essential information on the feasibility of CCS technology, it's important to note that the treated gas represents only 20 megawatts of output from the 1,300-megawatt coal plant. AEP has applied for stimulus funding to expand the Alstrom device to handle 235 megawatts of exhaust from the plant, but even that will represent only 18% of the power plant's output, which indicates how far the technology has to go. The larger facility will require the deep geologic injection of about 1.5 million metric tons of carbon dioxide per year. See the AEP press release.

CCS technology may also be applied to industrial facilities, like refineries and cement plants. To help move the technology ahead, DOE awarded $21.6 million in funds from the American Recovery and Reinvestment Act in early October to 12 CCS projects. The projects will demonstrate a variety of carbon capture technologies in applications relevant to power plants, refineries, paper plants, cement plants, and other industrial sources. Many of the projects involve injecting the carbon dioxide into geologic formations. Together, the projects represent a variety of geologic formations in diverse parts of the United States. DOE plans to invest a total of $1.4 billion in Recovery Act funds to spur progress on CCS technology. See the DOE press release.