Kentucky to bury carbon dioxide in ancient rock

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ANDY MEAD MCCLATCHY NEWSPAPERS, Published: June 6, 2009

HAWESVILLE, Ky. — Beside a cow pasture in Hancock County, scientists are drilling through 8,000 feet of rock, hoping to learn how to lock away forever an invisible gas that threatens Earth’s climate and our way of life.

Science fiction? No, but it’s a science experiment that, if it works, would be carried out on a scale never before seen.

The idea is to capture the carbon dioxide, or CO2, that spews into the air when coal is burned to produce electricity. The gas, which also occurs naturally, is one of the causes of global warming.

Drilling began April 24, and the work has continued around the clock. By mid-May, the drill had sunk to 3,660 feet. By early July, it will stop at 8,350 feet, in so-called “basement rock” that is more than 1 billion years old.

The $8.1 million Kentucky Geological Survey project is being paid for by $1.5 million from Kentucky taxpayers, with the rest coming from Illinois, the Tennessee Valley Authority and several companies, including E.ON U.S., the company that owns Kentucky Utilities.

The Hancock well in western Kentucky is one of a number of test wells in various stages around the country being coordinated by the federal Department of Energy. It was one of a $5 million package of carbon-dioxide-related projects ordered by the Kentucky General Assembly in 2007 when it approved House Bill 1. Because coal produces more than half the nation’s electricity and 90 percent of the power in Kentucky, the legislature was trying to get ahead of what everyone agrees will be laws that limit carbon-dioxide emissions.

“I know of no issue — no issue — that is any more important than this energy issue and how we will handle it,” said Democratic House Majority Leader Rocky Adkins.

Some of the state money, along with money from utilities, is going to the University of Kentucky’s Center for Applied Energy Research, where researchers are trying to find more efficient ways to strip the carbon dioxide from flue gases leaving power plants. At this point, center director Rodney Andrews said, the process is such an energy hog that a third more coal would have to be mined and burned just to capture the carbon dioxide.

If geologists find the kinds of rock they expect under Hancock, CO2 compressed so much that it has turned into a liquid will be sent down to porous layers somewhere between 3,780 and 7,780 feet.

There it will be forced into spaces in a type of limestone called Knox dolomite, which is found beneath much of Kentucky and the region.

“Imagine a jar of marbles,” said Brandon Nuttall, a geologist with the geological survey. “The spaces between the marbles — that’s where the CO2 will go.”

And that’s where, if the scientists are right, it will stay. Rick Bowersox, another KGS geologist who is co-manager of the project with Dave Williams, said part of the science is proven.

If the right kind of impervious rock is found above the porous layers and the well is sealed, he said, the carbon dioxide will have no place to go.

CO2 has been injected into oil wells beneath the North Sea for decades, he said. They aren’t doing it there to get rid of the CO2 but to push more oil out of the rock so it can be pumped to the surface.

Bowersox said he sees a certain balance in the closed loop of getting rid of CO2 by putting it down a well.

“We mine coal out of the ground to burn it, that produces carbon dioxide, and we capture that and put it back in the ground,” he said.

Bowersox said carbon storage is a good way to allow coal to be burned while other sources of energy are being developed. And, he said, someone might someday find a way to put huge amounts of CO2 to some beneficial use and pull it back out of the ground. HB 1 calls for another experimental well that is just getting started in Hopkins County. The CO2 pushed down that well will be used to push oil out.

An Eastern Kentucky well also is in the planning stages. That one has been delayed by a lack of partners to share the cost, but Adkins said an announcement could come soon.

Hancock will use 3,000 tons — a tiny amount compared with the many millions of tons produced by power plants each year. The CO2 will be commercial grade, the kind used to carbonate soft drinks or make dry ice for refrigeration.

Two nearby domestic water wells and several springs will be monitored for years to make sure none of the CO2 is getting to places it shouldn’t be.

State Energy Secretary Len Peters said figuring out how to capture CO2 and lock it in the ground is of vital importance to Kentucky’s long-term energy plans.

The state is putting more emphasis on alternative fuels, he said, but that won’t be enough.

“We can’t get from where we are today to where we need to be in 2025 without coal being part of the solution,” he said.