DECATUR, Ill. — In a major test of carbon-dioxide-storage technology, more than 865,500 tons of this gas has been injected since 2011 into the Mount Simon sandstone, a porous sedimentary-rock formation.
So far, there has been no leakage or other adverse impacts, according to Robert Finley of the Illinois State Geological Survey.
For carbon storage to make a big difference in the battle against global warming, fossil-fuel plants all over the world would have to find such sites to store their emissions.
At carefully selected sites, it is considered likely that 99 percent or more of the C02 would be retained for more than 1,000 years, according to a 2005 report from the Intergovernmental Panel on Climate Change.
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But some scientists have expressed concerns.
In a 2012 research paper published in the Proceedings of the National Academy of Sciences, Stanford University researchers Mark Zoback and Steven Gorelick wrote that storing large volumes of carbon dioxide injected into underground areas could build up enough pressure to significantly increase the risk of small earthquakes. Such seismic jolts could cause fractures, and offer a pathway for carbon dioxide to escape into the atmosphere.
“The more you inject, the bigger the risk,” said Zoback, a geophysicist.
Other scientists say that Zoback has overstated the seismic risks and that there are plenty of underground-storage structures that are unlikely to ever be breached by earthquakes.
Finley cites the Mount Simon sandstone formation, which underlays much of Illinois, as one of the most promising sites for safely storing large amounts of carbon dioxide. So far, he says, there have been no signs of troubling buildups of pressure at the Decatur site, which injects carbon dioxide from the fermentation at an Archer Daniels Midland corn-ethanol plant.
Storage tests have been conducted at sites around the world, and sometimes have been dogged by controversy from a wary public.
In Germany, one project was abandoned in 2011 due to protests.
In western Illinois, some farmers are uneasy about a proposal to store carbon dioxide that will be generated by FutureGen, a coal plant that is being converted to capture carbon emissions.
FutureGen plans to store the carbon dioxide beneath farm fields in a portion where the Mount Simon sandstone formation lies at 4,300 feet. This is substantially shallower than the site used by the Decatur demonstration, where the sandstone layer is found at the 7,000-foot depth.
More than a million tons of carbon dioxide annually are supposed to be injected into the FutureGen site. Farmer Andy Davenport worries some of the gas might eventually find its way to the surface and sour ground water that nurtures his crops.
“If there was a 1 percent chance of something like this going wrong, would I want my grandson or great-grandson to suffer for that?” said Davenport, who grows corn and soybeans near the injection site. “You are messing with our way of life.”
Hal Bernton: 206-464-2581 or firstname.lastname@example.org