Pumping carbon dioxide through hot rocks could simultaneously generate power and mop up the greenhouse gases produced by fossil fuel power stations, according to a new study.

Harnessing geothermal power involves extracting heat from beneath the surface of the Earth. Normally, this means pumping water down through hot rocks and extracting it again. But the new analysis suggests carbon dioxide could extract heat from rocks more efficiently than water.

Pruess calculated that the plant would perform more efficiently if carbon dioxide was used instead of water. "Initially I thought this was the most harebrained idea I had ever heard," he told New Scientist. "But the more I looked the more I liked it." Pruess discovered that using carbon dioxide to drive turbines and generate electricity, either directly or indirectly through the use of steam, could produce 50% more energy.

For the rest of the story:
http://www.newscientisttech.com/article/...cing-power.html

I don't see where the CO2 is consumed. I wonder what capacity the rocks would have in holding the CO2.

Pressurized CO2 seems to behave like water, but with better (larger) characteristics like heat capacity, dipole, etc.
I also noticed that, soilguy, about the "consumption" aspect. It would sequester some CO2 (used in the process) but how much would be generated just to compress the CO2?
Not too important a sink for CO2, but a real neat way to increase efficiency (more energy/effort).

Happy Trails....
~samwik

Which should be considered given this:

"Far from slowing down, global carbon dioxide emissions are rising faster than before, said a gathering of scientists in Beijing on Friday.

Between 2000 and 2005, emissions grew four times faster than in the preceding 10 years, according to researchers at the Global Carbon Project, a consortium of international researchers. Global growth rates were 0.8% from 1990 to 1999. From 2000 to 2005, they reached 3.2%.

Though alarming, the figures confirm expectations. "They make intuitive sense to me," says Jim Watson, deputy leader of the energy programme at the Tyndall Centre for Climate Change Research, UK."

Source and the rest of the story at:
http://www.newscientist.com/article/dn10507-carbon-emissions-rising-faster-than-ever.html