Cleaner coal: The Mountaineer Power Plant is the first in the world to capture some of the carbon dioxide it emits from burning 3.5 million tons of coal yearly and sequester it two and a half kilometers underground.Courtesy rmcgervey

Carbon dioxide removed from power plant exhaust and pumped underground

In addition to other environmental technology add-ons that strip out the fly ash, sulfur dioxide and nitrogen oxides, the Mountaineer Power Plant in West Virginia now also uses a carbon-capture unit built by Alstom. Dubbed the "chilled ammonia" process, baker's ammonia is used to strip carbon dioxide from the cooled flue gas and then, by reheating the resulting ammonium bicarbonate, captures that carbon dioxide, compresses it into a liquid, and

pumps it 2,375 meters straight down into the Rose Run sandstone, a 35-meter-thick layer with a nine-meter-thick band of porous rock suitable for storage. (or...) into Copper Ridge dolomite, which has much thinner strata for possible storage, more than 2,450 meters down. Thick bands of shale and limestone that lie on top ensure that the carbon dioxide does not escape back to the surface. Scientific American

Only 1.5% but first in the world

Only about 1.5 percent of the carbon dioxide billowing from its stack is being captured now. Scaling up the process to capture 20% of the CO₂ will cost at least $700 million. The removal of carbon dioxide will add abouts 4 cents more to the current cost of Mountaineer electricity (roughly 5 cents per kWh). This chilled-ammonia technology should be available commercially by 2015.

Learn more:
Slide show of Mountaineer Power carbon sequestering technology.
First Look at Carbon Capture and Storage in a West Virginia Coal-Fired Power Plant Scientific American