Carbon Capture Tech Makes Progress, But Enough?

by kespeland on November 3, 2009


(Part two of a two-part series on carbon capture and storage. Listen to part one here.)

This October, American Electric Power’s Mountaineer coal plant in West Virginia became the first to demonstrate it could capture carbon dioxide from the smoke stack and pipe it underground for storage.  It’s only capturing a fraction of the 9 and a half million tons of CO2 the plant emits every year, and engineers are still fine-tuning the process.  But project manager Brian Sherrick says what they learn from carbon capture and storage, or CCS, will still put the company ahead of the industry when congress passes climate change legislation.

Carbon capture equipment at the Mountaineer plant.

Carbon capture equipment at the Mountaineer plant.

“We think it’s imminent.  One of our main goals, overall goals, is to maintain coal as an affordable, reliable, and clean source of electricity.  It’s an abundant resource in the United States.  There isn’t one silver bullet to address global climate change.  CCS we believe will be part of the solution,” Sherrick says.

“This is not about making coal clean, as some people have claimed,” says Natural Resources Defense Council scientist George Peridas.  “Coal mining is ravaging communities in many areas of the country.”

Not everyone would agree with Peridas on that last point, but most industry and environmental groups agree on this:  “A few hundred power plants, coal plants are operating around the country, and they’re producing large amounts of global warming pollution, and this is where the carbon capture and storage technology comes in.”

The US Energy Information Administration projects that by 2030, 90 percent of the nation’s CO2 emissions will come from power plants that already exist.  Pittsburgh-based National Energy Technology Lab manager Jared Ciferno says scientists know how to capture the carbon from that power plant flue gas.  And they know how to store it underground.  But they don’t know how to do both on the scale an existing power plant needs. Ciferno is helping developm of some of the most promising methods.

“First and foremost, we need to scale up, whether they’re existing technologies or advanced ones, as well as they were not optimized for the power sector,” says Ciferno.

This Fall, the US Department of Energy invested $55 million dollars for laboratory or pilot-ready technologies.  Ciferno says the engineering hurdle will be testing those technologies in the real world.

“The majority of them are still on a relatively small scale, being developed in a laboratory scale.  We’re in the process now of looking at systems.  What kind of system does it need to be cost effective?”

Ciferno says the system basically has to include some kind of chemical that attracts and bonds with carbon dioxide molecules well enough to pull them out of the smoke stack gas, but not so well that the co2 molecules can’t later be plucked off and sent packing.  Getting that chemical reaction to be more efficient is the major problem scientists at several of the national labs are trying to solve right now.  But once we capture all that CO2, do we have—say, in the Ohio River Valley—safe places to put it?

“In much of Illinois, Indiana, northern Kentucky, the Mount Simon sandstone is the real focus of much of the geologic storage capacity,” says Dave Harris, with the Kentucky Geological Survey.

That layer of sandstone is many thousands of feet below the surface. And Harris says it’s porous enough to be a pretty good sponge for CO2—which would be compressed into a dense liquid and shot down a well. In Kentucky, industry and university partners have collaborated on two carbon storage test wells.  One’s in Hancock, the other in Boone County.  And they’re working.

“That certainly doesn’t give a green light for sequestration across the state.  We certainly need a lot more data points. But the results of these two tests are certainly favorable in that we were able to inject CO2 at rates approaching what would be needed on a commercial scale,” says Harris.

Harris says there are more potential storage sites throughout the region, too.  But scientists need to test and monitor them.  While they do, it could still be decades before carbon capture and storage technologies are ready for use on a wide scale.  And by then, Intergovernmental Panel on Climate Change models show us that carbon in our atmosphere will likely already have warmed the planet by several degrees.

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