May 9, 2008 9:20 AM PDT

Is carbon storage just a pipe dream?

Posted by Martin LaMonica

Researchers are committing billions of dollars to technologies that take carbon dioxide out of the atmosphere and store it underground, as more scientists and environmentalists question the wisdom of these plans.

Researcher Anders Hansson's at Linkoping University's Department of Technology and Social Change in Sweden this week published a study that concluded that the risks and complications of carbon capture and storage are grossly underestimated, according to a report in ScienceDaily.

A Berkeley Lab study identified locations of power plants, oil wells, and geological formations in the U.S. that have the potential to store carbon dioxide. Click on the image to go to the report.

(Credit: Lawrence Berkeley National Laboratory)

"In full scale, this technology only exists in the imaginations of the people developing it," Hansson said. "It's overly optimistic to place such great faith in it, considering all the uncertainties found in the scientific literature."

The technology is being tested but has not yet been done at a large enough scale--billions of tons of CO2--to effectively sequester carbon from the atmosphere, he said.

He argued that there must be more debate over the merits and drawbacks of carbon capture and storage or there could be a backlash against it. In a study last year, the Massachusetts Institute of Technology called for government-backed projects to attach carbon storage to coal plants.

Environmental watchdog GreenPeace issued a statement earlier this week, calling carbon capture facilities attached to coal-fired power plants "dubious technology" and a scam.

Other concerns related to putting carbon underground, which would be stored for decades if not hundreds of years, include the potential for leaking and the impact it could have on soil chemistry.

Moving forward, and underground
Even with reservations, development of carbon capture and storage, or CCS, is moving ahead because it is considered a potentially effective way to mitigate climate change.

On Tuesday, the Department of Energy awarded $126.6 million in grants to test the effectiveness of storing carbon dioxide in geological formations in Ohio and California.

The Department of Energy on Wednesday also communicated its requirements for $1.3 billion in potential funding for its FutureGen project. The DOE restructured the entire program earlier this year, citing escalating costs, in a move that remains controversial among lawmakers and energy companies.

The DOE funding will go to developing the gear to equip coal plants that use IGCC (Integrated Gasification Combined Cycle) technology with equipment that can store carbon underground. The goal is to have a commercial-scale operation by 2015.

The requirements call for each plant to sequester 1 million metric tons of CO2 annually and to capture a minimum of 81 percent of the CO2 emitted. The equipment must also remove 99 percent of sulfur from the coal's content and reduce nitrogen oxide to low levels.

Pumping CO2 is already done commercially to improve oil and gas exploration.

Exxon on Monday announced plans to build a facility that will take carbon dioxide from a natural gas treatment plant, freeze it, and then pump it into gas wells in a high-pressure steam, according to the Dallas Morning News.

VentureBeat earlier this week detailed a number of other carbon storage projects around the world, including China.