Thursday, June 14, 2007

Clean Coal Technology Involves More Than Plant & Fuel

Sequestration and Integrated Gasification Combined Cycle (IGCC) are being touted as solutions to reducing the carbon footprint of coal-fired electric power plants. This combination is the new mantra of politicians much as the 'wind and solar' combination is the mantra of traditional environmentalists. But saying it will not get us there. There are some pratical engineering steps that will need to be addressed by the public before sequestration and IGCC can become reality.

First there must be a nationwide pipeline that can transport carbon dioxide to various underground storage areas. Of course Not In My Backyard (NIMBY) advocates work to prevent almost every proposed development project, particularly high-powered electricity line and natural gas pipelines. The Energy Policy Act of 2005 has given the Federal Energy Regulatory Commission (FERC) authority to override state authority in the national interest, but it is yet to be proven that this new law will be effective in this regard.

The volume of gases being sequestered must also be reduced. Since nitrogen makes up almost 80 percent of that volume it must be removed, to the largest extent practicable, from the stack gases. To the extent practicable oxygen should be the exclusive gas in the firebox. By using an almost pure oxygen feed into the firebox a pure stream of carbon dioxide will be created in the flue gas. Where will this oxygen come from and how will it be economically produced? From the hydrolysis process used to separate hydrogen and oxygen in water. As we move towards a hydrogen economy the oxygen produced from hydrolysis can be in the other pipe heading back to the power plant next to the carbon dioxide pipeline going to geological stoarage areas. Significantly reducing the volume of nitrogen in the sequestration stream will provide more capacity in the valuable subterranean storage areas. The higher oxygen content as a feed gas should also increase the efficiency of the burn, particularly in supercritical boilers.

Finally, some sort of 'hold-harmless' provision (byond limited liability) will have to be assigned to sequestration companies and the federal government should assume liability for unforeseen consequences of sequestration. After all, it is the public that is demanding more and more electricity in a global warming world 24-7-365.

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