Rock Could Reduce
by Shannon Dininny, Associated Press
RICHLAND, Wash. -- Millions of years ago, lava repeatedly spewed from giant fissures in the earth's crust, engulfing more than 60,000 square miles of the Pacific Northwest. The floods left behind layers of dark gray basalt thousands of feet thick.
The basalt still lies beneath the surface in much of the region, and researchers now believe they have found a key use for the porous rock: storing carbon dioxide emissions from power plants.
Called carbon capture and sequestration, the process involves capturing the emissions, separating the carbon dioxide and sequestering it for commercial use or for injection back into the earth.
The technology isn't entirely new. In the North Sea, carbon dioxide has been injected into a saline aquifer in order to avoid European taxes on carbon emissions. In other places, the gas is injected into oil fields to push more oil out of the ground. If pure enough, carbon dioxide can even be sold for commercial or industrial uses, such as to carbonate soda pop.
But there's "not enough soda pop in the world" to make a dent in the level of carbon dioxide emissions from power plants, said Stuart Dalton, director for generation at the Electric Power Research Institute in Palo Alto, Calif., a research and development collaborative sponsored by the country's electric utilities.
For thousands of years, carbon dioxide levels in the atmosphere hovered at about 250 parts per million. Since the onset of the industrial revolution, levels have risen to more than 375 parts per million.
Whether basalt will prove to be ideal for long-term storage on a large scale remains a "big if," said Peter McGrail, a researcher at Battelle Pacific Northwest Division, a U.S. Department of Energy supported science lab and partner in the Big Sky Carbon Sequestration Partnership, a regional study into carbon capture and sequestration technologies.
As the lava cooled, pockets of trapped gas created a porous structure ideal for injecting carbon dioxide. Also, the basalt reacts with the carbon dioxide to create a solid mineral that doesn't damage the structure or integrity of the entire rock, McGrail said.
McGrail's researchers now are investigating sites for a pilot test slated to begin in 2007. Carbon dioxide would be injected into basalt at about 3,000 feet, where the water is not suitable for drinking or irrigation.
The key is to prove the technology is both environmentally viable and cost-effective.
"The opportunities for basalt are substantial in our region, but also, there are substantial opportunities in other parts of the world," said Susan Capalbo, an economics professor at Montana State University and director of the partnership. "We really need to make sure this is affordable, at the same time it isn't damaging the environment."
The biggest cost associated with the technology centers on capturing the carbon dioxide. A traditional power plant can use up to a third of its power capturing carbon dioxide, which could more than double the cost of that power for consumers, Dalton said.
The impact is far less significant for what's called an integrated gasification combined cycle plant. Such plants generally use coal or petcoke, the waste product from oil refineries, which is then turned into a gas to be burned to generate power.
They use only about 6 percent of their power to separate the carbon dioxide, increasing the cost of power by perhaps a third, Dalton said.
Already, one Northwest utility is planning to take advantage of that technology. Energy Northwest, a joint agency comprising 19 public utilities and municipalities, last year announced plans to build a plant in Kalama, west of the Cascades in southwest Washington.
The company already operates a nuclear plant, a hydropower project and wind, solar and biomass power projects. Its Kalama project will be designed to capture carbon dioxide emissions for potential injection into the region's basalt, at an added cost of $35 million, spokesman Brad Peck said.
"We didn't choose the Port of Kalama for this project at random," Peck said. "There was some very specific considerations, and one of those is that it sits atop basalt formations."
But a great deal of research into the technology still needs to be done before the company commits to the process, he said.
The Big Sky project is one of seven regional partnerships backed in part by the Energy Department, which has touted the technology as one way to use the country's 250-year coal supply in a clean manner. The department spent $66.3 million on the carbon research in 2006, up from $44 million in 2005.
But utilities are unlikely to spend more on the technology unless they are forced to -- either through carbon dioxide limits or other measures, said David Hawkins, director of the Natural Resources Defense Council's Climate Center.
"The concept of storage in formations we think holds some promise. It's not a substitute for the lead strategies, in our view, like efficiency and renewables, such as wind energy," he said.
Capalbo believes carbon dioxide limits are just around the corner.
"I personally believe we will have some form of constraint some time in the future," she said. "If we work with industry now and know what some of their constraints are, we can create a win-win situation for everyone."
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