|Wallula test begin to trap CO2 underground||
Carbon dioxide is being injected half a mile deep into the ground at Wallula to test whether the greenhouse gas can be stored safely and permanently in ancient basalt flows.
Over four weeks, more than 1,000 tons of carbon dioxide -- the predominant gas implicated in climate change -- will go into the ground on the campus of the Boise Inc. pulp and paper mill under the direction of Battelle researchers based at Pacific Northwest National Laboratory. The mill sits atop dozens of volcanic lava flows in layers 8,000 feet or more underground, part of the deep basalt formations that cover parts of Washington, Oregon and Idaho.
Laboratory tests have shown carbon dioxide can react with basalt to quickly form solid rock, said Pete McGrail, Battelle project manager.
"However convincing the laboratory data may be, proving the same processes operate deep underground can only be done by conducting a successful field demonstration," he said. "We have taken the very first steps to do that here in Wallula."Preparations have been under way for years by Battelle, Boise and the Big Sky Carbon Sequestration Partnership to study the geology at Wallula and obtain funding and permits. Some of the deep layers of lava underneath Wallula are pockmarked with holes, like a sponge. The carbon dioxide, converted from gas to liquid, will make its way through the holes, absorbing water and reacting with elements in the basalt to form calcium carbonate -- the same substance that makes up limestone. McGrail expects the rock to start forming within weeks, permanently securing the carbon dioxide away from the atmosphere. Scientists plan to conduct research at the site for 14 months, withdrawing fluid samples from the injection well to look for chemical changes limestone crystals. The results will be compared with predictions made using Pacific Northwest National Laboratory's supercomputer. It's a relatively small field test.
The amount of carbon dioxide being injected is equal to the amount a typical coal-fired power plant emits in few hours, according to the Big Sky Carbon Sequestration Partnership, which is led by Montana State University. But the United States and portions of Canada have enough potential capacity in geologic formations that they would not run out of space for carbon dioxide for 5,700 years, according to recent estimates by the Department of Energy.
"Perhaps more important are the basalts available in India and China, two countries with increasing energy use," said Lee Spangler, director of the energy research program at Montana State University. It's been about a decade since McGrail and fellow scientist Todd Schaef had a "eureka moment" that's led to the present field test. They had taken small samples of Mid-Columbia basalt and exposed it to carbon dioxide and water under pressure. They were interested in seeing if the carbon dioxide over long periods of time would react with the minerals in the basalt to form limestone crystals. Instead, when they cracked open the first pressure vessel after a matter of weeks, they found substantial crystallization. "That was one of the moments I said I cannot believe that happened," McGrail said. That early research also has led to other ideas.
Another project of McGrail's will see if the same layers of basalt could be used for compressed-air power storage to make seasonal and intermittent power generated by wind more practical. At Wallula, about $12 million has been committed to the pilot project.
(Source: Tri-City Herald)
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