From the “MTBE is perfectly safe department” and Duke University:
Leaking underground CO2 storage could contaminate drinking water
DURHAM, N.C. — Leaks from carbon dioxide injected deep underground to help fight climate change could bubble up into drinking water aquifers near the surface, driving up levels of contaminants in the water tenfold or more in some places, according to a study by Duke University scientists.
Based on a year-long analysis of core samples from four drinking water aquifers, “We found the potential for contamination is real, but there are ways to avoid or reduce the risk,” says Robert B. Jackson, Nicholas Professor of Global Environmental Change and professor of biology at Duke.
“Geologic criteria that we identified in the study can help identify locations around the country that should be monitored or avoided,” he says. “By no means would all sites be susceptible to problems of water quality.”
The study appears in the online edition of the journal Environmental Science & Technology, at http://pubs.acs.org/doi/abs/10.1021/es102235w.
Storing carbon dioxide deep below Earth’s surface, a process known as geosequestration, is part of a suite of new carbon capture and storage (CCS) technologies being developed by governments and industries worldwide to reduce the amount of greenhouse gas emissions entering Earth’s atmosphere. The still-evolving technologies are designed to capture and compress CO2, emissions at their source – typically power plants and other industrial facilities – and transport the CO2 to locations where it can be injected far below the Earth’s surface for long-term storage. The U.S. Department of Energy, working with industry and academia, has begun the planning for at least seven regional CCS projects.
“The fear of drinking water contamination from CO2 leaks is one of several sticking points about CCS and has contributed to local opposition to it,” says Jackson, who directs Duke’s Center on Global Change. “We examined the idea that if CO2 leaked out slowly from deep formations, where might it negatively impact freshwater aquifers near the surface, and why.”
Jackson and his postdoctoral fellow Mark G. Little collected core samples from four freshwater aquifers around the nation that overlie potential CCS sites and incubated the samples in their lab at Duke for a year, with CO2 bubbling through them.
After a year’s exposure to the CO2, analysis of the samples showed that “there are a number of potential sites where CO2 leaks drive contaminants up tenfold or more, in some cases to levels above the maximum contaminant loads set by the EPA for potable water,” Jackson says. Three key factors – solid-phase metal mobility, carbonate buffering capacity and electron exchanges in the overlying freshwater aquifer – were found to influence the risk of drinking water contamination from underground carbon leaks.
The study also identified four markers that scientists can use to test for early warnings of potential carbon dioxide leaks. “Along with changes in carbonate concentration and acidity of the water, concentrations of manganese, iron and calcium could all be used as geochemical markers of a leak, as their concentration increase within two weeks of exposure to CO2,” Jackson says.
These global warmers think they can control Nature and they are planning to govern upon the World, as they think themselves the most intelligent and prepared and gifted people of the whole humanity: The same thought was recently expressed by CANCER CELLS when they planned to take over the whole body: They succeeded and gloriously died with it!
Goo idea! : Some Cobalt 60 will work for them, conveniently dissolved in Kool-Aid 🙂
What is the average Energy Returned On Energy Invested (EROEI) ratio for a typical carbon sequestration facility?
Let me help you out here. The answer is < 1. It is a total waste of resources and will generate more CO2 to design, manufacture, install and operate a CS facility than the CO2 it is hoping to sequester.
It is easier to pick yourself up off the floor by pulling on your bootstraps, than it is to reduce CO2 emissions by sequestering CO2.
George E. Smith said
<i?Perhaps they should reduce the CO2 to carbon, and store that down in the salt mines; we will need it to blacken the ice when the big freeze gets underway.
Perhaps terra preta do indios, black earth of the Indians would be a better idea/
I love how this “may” present problems but “there are ways to avoid or reduce the risk”. I’m sure none of those ways to avoid or reduce risk have problems of their own that end up worse than what they were trying to fix. Oh wait, that happened already.
Jeff L says:
November 12, 2010 at 7:20 am
“Reservoirs are reservoirs, oil or no oil. Top seals are top seals, oil or no oil
This is concept is child’s play for any petroleum reservoir engineer.
Find the right reservoirs with the right properties – of which there are unlimited numbers of – and start injecting. If you can do it into an oil reservoir & get economic benefit from it , all the better. Of course, this all costs $s, but the cost-benefit curve of this operation is not what the article is about & will not debate it.”
There is a crucial quantitative difference between sequestration and secondary recovery using CO2. To sequestrate the CO2 that results from burning the contents of an oil or natural gas reservoir would require more volume than the original reservoir contains. Even compressed to liquid density at ~1000 atmospheres pressure, the CO2 would take up about a third more space, and most existing oil reservoirs would be unable to contain pressures this high safely and permanently. Old coal mines would as a rule be even less suitable. One could of course use much lower pressures, but then one would need proportionately larger reservoir volumes. It would be hard to find enough currently unoccupied reservoirs for more than a few decades’ worth of CO2.
By the way, contrary to what many commenters seem to assume, capturing and compressing the CO2 for sequestration need not consume a large fraction of the power produced. An upper limit is the 5MJ/kg to extract CO2 directly from the atmosphere using NH3 with no recycling of sensible heat, plus the 0.4MJ/kg to compress it to 1000 bar. The former figure should be reduced considerably in practical commercial plants. Capturing the CO2 from flue gases should not require more than ~0.25MJ/kg, by compressing the gases above 74 bar and cooling to 304K, tapping off the liquid CO2 then allowing the residual nitrogen to re-expand. Other techniques may be able to reduce this further (though may hit snags with impurities, which however would not be much of a problem in the simple mechanical process). Separating out the nitrogen before combustion would be another option. If we assume a 40% efficiency (thermal to electrical), we require ~1MJ/kg CO2 of primary energy, or about 10% of the total power. Not negligible, but not a show-stopper either. It will take some time to develop industrial scale systems to such efficiencies, but there’s no reason to doubt their practicability. Transporting the CO2 to the sequestration sites would also be a major logistical issue (unless we extract the CO2 from the atmosphere locally), but again not an insoluble one. Just needlessly costly.
CO2 regularly contaminates my cooking. Just poured the vile stuff (in the form of Guinness Stout) in a mean vat of venison stew. Contaminated the cook a bit too.