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Carbon goes undercover

How it works: Heavy CO2 emissions are pumped underground where they are se a led in by impervious rock. What it means: Less CO2 will be sent into the atmosphere, reducing the greenhouse effect involved in global warming.

By JAMES THORNER
Published December 11, 2006

Burying carbon dioxide The best-case scenario injects CO2 emissions from power plants underground to help dislodge oil and natural gas.The valuable commodities rise to the surface and C02 fills the void for what scientists hope will be thousands of years. And the process need not be a budget buster because oil companies may pick up part of the tab.

ADVERTISEMENT [Times file photo] Coal burning power plants are one of the contributors to CO2 emissions in the Tampa Bay region. Area power companies are teaming up to confront the issue.

Florida power companies are mulling a new technique to rid themselves of carbon dioxide, the greenhouse gas most blamed for raising planetary temperatures.

Bury it.

Pumping smokestack emissions deep underground into oil wells or Gulf Coast salt formations essentially means creating landfills for carbon dioxide.

Sealed by impervious rock, the reservoirs could hold the CO2 for millennia - or until we've developed cleaner burning fuels that make the global warming issue irrelevant.

Sound farfetched? This "carbon sequestration" process is already operating commercially in the North Sea of Europe and in the upper Midwest and Canada. CO2 injections there double as an oil and natural gas extraction technique.

Sequestration is part of a three-legged approach - energy efficiency and clean alternative fuels being the other two - the government is touting to cut greenhouse gases.

"You could inject for hundreds of years. The storage capacity is just enormous," said John Litynski of the National Energy Technical Laboratory, leading the push for sequestration.

Progress Energy Inc., TECO Energy Inc., Gulf Power Co. and Florida Power & Light Co. are members of the Southeast Regional Carbon Sequestration Partnership, one of seven regional authorities trying to advance the science of CO2 storage.

Atmospheric carbon dioxide, a byproduct of burning fossil fuels, helps trap heat from the sun. Release too much of the gas and the atmosphere thickens, potentially leading to higher temperatures.

TECO has embarked on a carbon dioxide reduction plan using natural gas-fired turbines. But it anticipates using sequestration to rid itself of residual CO2 from coal-burning operations. Its state-of-the-art power plant in Polk County that uses coal to make a clean-burning gas is a prime candidate.

"We're just trying to keep abreast of technological advances," spokesman Rick Morera said.

For St. Petersburg's Progress, sequestration is all the rage at corporate events, spokeswoman Cherie Jacobs said. But it remains a prospect not yet ready for prime time, at least in Florida.

Progress already uses clean-burning technology at its Crystal River nuclear plant in Citrus County. But its coal-powered plants at Crystal River and oil-burning plants, like the one at Anclote near Tarpon Springs, could benefit from sequestration.

Gulf Power, the energy company in the Florida Panhandle, could be the furthest along. It's months from surveying potential storage sites, including oil wells dotted throughout extreme northwest Florida.

Oil companies might even pay for the privilege. A common use for CO2 is "enhanced oil recovery," pumping the gas underground to force out hard-to-reach petroleum and natural gas. The carbon dioxide becomes trapped in pockets vacated by the oil.

A Gulf Power sister company has joined a demonstration project that will pump carbon dioxide into a salt reservoir 9,000 feet underground in southern Mississippi.

Scientists suspect similar formations along the Gulf Coast also could fit the bill geologically. A government map shows potential CO2 burial sites covering roughly all of Florida south of Citrus County.

The government doesn't currently regulate CO2, but Florida power companies assume such restrictions are coming.

"You'd have to be blind and deaf not to see all the bills being written up," said Keith Harrison, principal research engineer with the Southern Co., Gulf's parent. "You can see the storm building."

The biggest headache hasn't been storage, but how to capture, condense and transport carbon dioxide at power plants. The federal government estimates that current, crude methods of isolating CO2 from flue gas at power plants could double the price of electricity.

Needless to say, few would support what would essentially be a massive carbon tax on consumers. The government's goal is for sequestration to add no more than 10 percent to the cost of power. TECO's Polk plant is ideal since its up-to-date technology promotes cheaper capture of carbon dioxide.

Then there are skeptics like Tom Herbert, a Tallahassee-based consulting geologist for the government and private companies. He wonders whether burying the gas would have a practical effect.

"I look at it as a scale issue. We've been burning hundreds of years. Can we as humans operate at a global scale that means something?" Herbert said.

Supporters say yes and point to experiments like the Weyburn project in North Dakota. Dakota Gasification Co. pipes carbon dioxide waste from a synthetic fuel plant 200 miles north to Saskatchewan. There, energy conglomerate EnCana injects the C02 to wring oil from below the surface.

Dakota earns about $30-million a year from selling its waste gas, but the biggest plus could be environmental. Over the life of the contract, EnCana could trap 20-million tons of CO2. It's a drop in the bucket compared with yearly U.S. output of 7-billion tons, but it does equal annual emissions in Maine.

The Norwegians launched the first commercially successful CO2-injection program in a North Sea gas field in 1996.

Researchers estimate U.S. coasts could theoretically stash thousands of years worth of CO2. Ideally, Florida, with its growing hunger for power, would inject CO2 underground near the source. Some expect half of all man-made carbon dioxide will vanish beneath our feet by 2050.

"It's not going to do the entire job. It has the potential to solve 30-50 percent of the emissions issue," Litynski said. "We need to be ready."

Burying carbon dioxide

The best-case scenario injects CO2 emissions from power plants underground to help dislodge oil and natural gas. The valuable commodities rise to the surface and C02 fills the void for what scientists hope will be thousands of years. And the process need not be a budget buster because oil companies may pick up part of the tab.

[Last modified December 10, 2006, 19:46:33]