4/29/2007

Carbon Capture

Remember this quote from the Tribune:

SME says it has new plans to try to capture carbon dioxide emissions from the plant. How much would this increase the power cost to members, and is there a chance this would be so costly it would make the project unworkable?

"They (SME officials) are committed to developing a program," Lawton said. He said it could involve carbon dioxide capture at the new plant in Great Falls. A boiler manufacturer is initiating a demonstration project in Wisconsin. Lawton said SME also is looking at mitigation efforts to lessen the impact of more carbon dioxide in the atmosphere, a factor cited in global warming theory. Planting trees can mitigate an increase in carbon dioxide."

I came across the following in the Environmental Impact Statement:
The U.S. Department of Energy, among other agencies and institutions, is conducting various research projects on methods for efficient capture and storage of CO2. However, research has not yet identified any commercially available technique that can capture much of the CO2 from a large-scale power plant under normal conditions. (Markel, 2005) Preliminary projections suggest that the likely cost of carbon capture would add 2.4 cents / kWh for a pulverized coal plant, and would probably also educe the power output of the plant by roughly 25 percent (Herzog and Golomb, 2004).

As to storage of the carbon, the techniques under study include injecting it below ground such as into oil or gas reservoirs to help push out more oil and gas, or into
un-mineable coal beds, to push out the natural gas (methane) that occurs with the coal. Another idea is to inject CO2 into beds of basalt rock, letting the CO2 become bound to the basalt. This method is being researched at Montana State University and is still in the experimental stages. (Capalbo, 2005). It is not a concept [the Highwood Generating Station] could count on using. Even if some form of underground carbon storage were to become practical, the transport of the CO2 to the underground storage site would add further economic and energy costs.

Other methods for CO2 sequestration include aforestation (planting tree stands) and agricultural sequestration. These methods seek to store carbon in standing biomass (e.g. trees) or in increased organic matter in soils. Certain states and regional programs offer incentives for sequestration through these methods....The area of land that would have to be reforested or afforested to fully offset carbon emissions from the HGS (or any comparable fossil fuel generation) would be enormous and impractical. There is simply no enough arable land available for aforestation on the entire earth to fullly offset global annual carbon emissions; therefore, while this process will measurably reduce the accumulation of CO2 in the atmosphere while providing other environmental and socioeconomic benefits, it cannot be considered as an option that would make coal consumption/combustion "carbon neutral".

Therefore, while direct capture and storage of the carbon emitted by coal fired power plants is not practicable at this time, offsetting the power plant's emissions with programs that tie up increased amounts of carbon in biomoass are technically feasible economically attractive depending on the program's structure.
You tell me if these people are serious about implementing some sort of carbon capture, or if they are just saying it to quell the opposition.

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