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Germany Fired Up Over Clean Coal
MIT's Technology Review is reporting on the world's first coal-driven power plant designed to capture and store C02 emissions. "Vattenfall's small 30-megawatt plant burns the lignite in air from which nitrogen has been removed. Combustion in the resulting oxygen-rich atmosphere produces a waste stream of carbon dioxide and water vapor, three-quarters of which is recycled back into the boiler. By repeating this process, known as oxyfuel, it is possible to greatly concentrate the carbon dioxide. After particles and sulfur have been removed, and water vapor has been condensed out, the waste gas can be 98 percent carbon dioxide, according to Vattenfall. The separated carbon dioxide will be cooled down to -28 C and liquefied. Starting next year, the plan is to transport it by truck 150 miles northwest, to be injected 3,000 meters underground into a depleted inland gas field in Altmark. Ideally, in the future, the gas will be carried by pipeline to underground storage, says Vattenfall. "
Huh, I thought it was because the earth has a funny way of shifting around and things don't always stay buried for very long which could be problematic for pressurized gasses, but I guess it's because of anti-technology ecofascists.
It's being done, it's being studied, and so far the science indicates it is pretty safe. Pressurized gasses - like natural gas - have existed underground for ages and we've managed to deal with them.
Actually, the natural tendency is for it to percolate out of the ground. We only find natural gas (and oil) in lens-shaped non-porous rock formations which trap the rising gas before it reaches the surface. This is called an anticline. Luckily, the most economical use for the CO2 produced is to pump it back down into the trap, where it will presumably remain for another million years.