A new look at retrofitting power plants
West Virginia power plant 'injects' carbon monoxide into the ground.
Tue, Sep 22, 2009 at 12:23 PM
UNDERWORLD: Coal plants find a new home for carbon monoxide. (Photo: dsearls/Fickr)
The New York Times reports that a power plant in West Virginia is taking an innovative step to lower the carbon dioxide it puts in the atmosphere ... by putting the gas into the ground instead. Mountaineer Power Plant will become the world's first coal-powered plant to take this step in emissions management, capturing and then burying the gas in two giant "wells" outside the facility. Much of the world's focus on carbon dioxide management involves developing new technology to capture and store the troublesome gas, the Times reports, and the West Virginia facility is drawing visitors from around the world to learn about the experiment. Retrofitting power plants like the Mountaineer could potentially provide a more economic solution than building new plants.
The process works when engineers convert the carbon dioxide into a fluid by mixing it with a chilled chemical similar to ammonia and then reheating it to separate the gas from the smoke. Next, they pump the CO2 into a layer of sandstone more than a mile beneath the earth. The liquid is then pumped into a layer of dolomite another 400 feet deep -- so deep that some experts are concerned the process might cause earthquakes. The current plan is to inject 100,000 tons of carbon dioxide each year, about 1.5 percent of the yearly emissions, with space to inject more should a law be passed controlling emissions. American Electric Power, the nation's largest energy producer, says they could "capture as much as 90 percent of the gas" they currently emit if necessary.
There are, however, economic concerns with this method of CO2 management. Experts fear the process might involve so much energy as to make it not worth the effort, making the coal-powered plants less efficient than solar or nuclear alternatives. The experiment depends on the idea that the CO2 will remain in the earth for thousands of years rather than enter the atmosphere, where it will trap heat. Since this technology is so new, environmentalists worry that the gas might not stay in the ground as planned or, worse, pollute ground water and form carbonic acid.
The Times quotes David Holtz, executive director of the environmental group Progress Michigan, saying, "Coal is the drug of choice of a major industry with a lot of political power ... There's not evidence that burying carbon dioxide in the earth is a better strategy than aggressively pursuing other alternatives that are clearly better for the environment and will in the long run be less costly." Holtz compares this new strategy to a "methadone cure for addiction."
The power company counters that the capture method is a solution that is relatively quick to install and that retrofitting plants is perhaps the best choice for controlling the gas for the immediate future. External research groups are monitoring the areas around the injection sites to measure changes in pressure and temperature and keep track of how the carbon dioxide spreads. The Environmental Protection Agency will also monitor the site to see if the carbon dioxide is seeping.