CARBON STORAGE LOCKER: Burying CO2 in basalt rock formations, like the one pictured here, may prove the safest way to successfully sequester the ubiquitous greenhouse gas.
Image: Photograph from cruise AT11-16, Alvin Dive 4045; http://4dgeo.whoi.edu
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Volcanic rocks deep beneath the sea off the coast of California, Oregon and Washington State might prove one of the best places to store the carbon dioxide emissions that are causing global warming, a new study finds. In fact, the very instability that causes earthquakes and eruptions adds an extra layer of protection to keep the CO2 from ever escaping.
The U.N. Intergovernmental Panel on Climate Change (IPCC) and other experts, including the G8 (Group of Eight) leaders of the world's richest nations, have called carbon capture and storage a critical tool in the fight against climate change. In essence, such technology catches the CO2 and other pollutants emitted when coal or other fossil fuels are burned. It is then compressed into a liquid and, theoretically, pumped deep beneath the surface to be permanently trapped.
Such technologies have been demonstrated on a small scale to enhance the recovery of oil from tapped out fields; pumping down the CO2 pushes up more of the black gold. But geophysicist David Goldberg of Columbia University's Lamont–Doherty Earth Observatory in Palisades, N.Y., and his colleagues found that pumping such CO2 into basalt rock beneath the ocean floor might be a better solution.
Specifically, liquid CO2 is heavier than the water above it at 8,850 feet (2,700 meters) or more under the surface, meaning any leaks would never bubble back into the atmosphere. Further, the CO2 mixes with the volcanically warmed water below the surface and undergoes chemical reactions within the basalt (the black rock created from rapidly cooling lava) to form carbonate compounds—otherwise known as chalk—effectively locking up the greenhouse gas in mineral form. The 650-foot (200-meter) layer of marine sediment on top of the basalt rock acts as yet another barrier. "You have three superimposed trapping mechanisms to keep your CO2 below the sea bottom and out of the atmosphere," Goldberg says. "It's insurance on insurance on insurance."
The researchers estimate, conservatively, that at least 229 billion tons (208 billion metric tons) of carbon could be stored in the basalt formations of the Juan de Fuca Plate 100 miles (160 kilometers) off the U.S. west coast in this way—or the equivalent of 122 years of all U.S. emissions of 1.9 billion tons (1.7 billion metric tons) annually.
It is unlikely that all of the CO2 emitted in the U.S. could ever be captured and transported—whether by pipeline or tanker—to the west coast for injection, but local coal-fired power plants might be able to take advantage of the formation.
"On the one hand you wouldn't want to bet the future of U.S. climate policy on it until one has done more work, but on the other hand it looks quite promising," says engineer M. Granger Morgan of Carnegie Mellon University, a carbon sequestration expert. "In contrast to CO2 injected in the ground, which is buoyant, in this case it won't be buoyant."
Such formations are also potentially accessible in many parts of the world, according to Goldberg, who is currently researching the global resource. The next step will be a small pilot project during which researchers plan to inject some CO2 into the undersea formation and see what happens—a process that will take at least three years. Also, colleagues in Iceland will begin pumping CO2 from a power plant into similar basalt formation later this year, but on land. "The volumes [of storage] we're talking about are huge and the problem is huge," Goldberg says. "The prize is very large here with this option. It's worth a serious look."
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14 Comments
Add CommentI became tired with and stop wondering at the misleading provided steadily, which is global warming is caused by humans , because such an approach is a very profitable fairytale of, by and for privileged-with-paid-employment at top positions in too many places round a globe, perhaps.
Reply | Report Abuse | Link to thisFighting a global warming, sounds as much realistic as postponing a sunset for either incapability to win over the nature but ADAPTING to the natural processes a realistic task is.
Michael Kerjman
What will be the effect of pumping all this CO2 down there? What will we be displacing, where will it go, and what effect will it have?
Reply | Report Abuse | Link to thisx
Reply | Report Abuse | Link to thisWhoa! Has anyone stopped to consider that for every atom of carbon sequestered in this way, two atoms of oxygen are removed from the atmosphere? Oxygen is normally recycled back into the atmosphere by plants when they convert CO2 and H2O to carbohydrates. Thus, it is a closed loop, in which combustion "borrows" oxygen from the atmosphere, to be returned to the atmosphere by photosynthesis. Sequestering carbon dioxide removes oxygen from the atmosphere but provides no way to recycle it back into the atmosphere. So while the percentage of CO2 in the atmosphere may stop increasing, the percentage of oxygen will decrease. It seems to me this concept of sequestering CO2 needs to be considered in terms of its impact on the amount of oxygen in the atmosphere.
Reply | Report Abuse | Link to thisDon't worry about the oxygen. Even if all fossil fuels are burned (and we'll hopefully not do that!), it's only a tiny fraction of the atmospheric oxygen that's taken away. It's a total bargain compared to the addittional impact of global warming if we don't sequester any carbon.
Reply | Report Abuse | Link to thisLet's examine the numbers. First, it should be understood that the mass of oxygen in the atmosphere is both finite and constant, having taken billions of years to attain its current mass of 10^15 tons. Oxygen consumed in combustion is replenished by photosynthesis. Sequestering CO2 removes oxygen from the atmosphere but does not replenish it.
Reply | Report Abuse | Link to thisGlobal consumption of coal is 6 billion metric tons per year, and global consumption of oil is 30 billion barrels per year.
Burning one metric ton of coal produces 1.83 metric tons of CO2. Therefore, the mass of CO2 from the burning of coal amounts to 11 million metric tons per year. The combined liquid fuels from an average barrel of crude oil will produce a minimum of 0.317 metric tons of CO2 when consumed. 30 billion barrels of oil are consumed per year, producing 9.5 billion metric tons of CO2.
The total mass of CO2 produced from the burning of coal and oil amounts to approximately 20 billion metric tons per year. The molar mass of CO2 is 44 grams, of which 32 grams is oxygen, so CO2 is 32/44 or about 73% oxygen. Therefore, the 20 billion metric tons of CO2 produced each year from the burning of coal and oil consumes 14.6 billion tons of oxygen per year, or approximately 1.5 x 10^10 metric tons. In a century, that amounts to 1.5 x 10^12 or 1.5 trillion metric tons of oxygen bound to carbon in CO2. In terms of the total mass of 10^15 tons of oxygen in the atmosphere, that amounts to
1.5 x 10^12 / 1 x 10^15, or 0.15% of the oxygen permanently removed from the atmosphere per century by sequestration at current rates of consumption. For that reason, I do not believe that CO2 sequestration is a good idea. I believe the focus should be on renewable sources of energy which have zero net production of CO2. Note that the burning of ethanol derived from cellulose results in zero net production of CO2, because for every molecule of CO2 produced by combustion, an O2 molecule is released back into the atmosphere by photosynthesis.
0.15% of the total oxygen removed from the atmosphere per century may not seem like a lot, but it would amount to 1.5% of oxygen permanently removed from the atmosphere in a thousand years. I do not believe it is wise for humans to engineer the composition of the atmosphere of the planet to that extent, without knowing the possible consequences.
I wrote:
Reply | Report Abuse | Link to this"Therefore, the mass of CO2 from the burning of coal amounts to 11 million metric tons per year."
Of course, "11 million" was a typo; it is 11 billion metric tons. For some reason, my paragraph breaks were removed.
Personally, I am interested in the practical recycling of CO2 for future usage when global cooling to come.
Reply | Report Abuse | Link to thisM.Kerjman
I see jumping in this concept a bit dangerous, as Mr. S. Brown notes, tilting the balance of the atmosphere composition is a extremely dangerous game. Think of:
Reply | Report Abuse | Link to this-disrupting the atmosphere layers equilibrium can lead to changes in the shielding effect from outer radiation of all kinds (energy levels).
-disruption in global communications (ionization patterns in layers could change).
-change on wind patterns due to different air densities and temperatures.
-at ground level, it could mean iradiation changes with increasing/decreasing global and local temperatures. Variations in temperature ranges due to changes in air convection properties.
-living organisms (humans included): adaptation to changing levels of oxygen (decreasing) could lead to drastic changes in species (e.g., emergence of new virulent microbial strains resistant to the host's conventional fighting mechanisms).
-not to mention how costly might be to pump down all those millions of metric cubics of CO2, along with the almost impossible task of capturing it first.
The list could be as long as one has time to sit and write, and his/her knowledge allows to elaborate more possible and realistics scenarios.
I think that the answers are somewhere else, perhaps under power generated by sea waves, geothermal, solar and wind, or any combination of them.
Isn't carbon dioxide an industrial gas? Why not just sell it to soda companies so they can pump it into soda? Why go to the ridiculous expense of building underground or undersea containment?
Reply | Report Abuse | Link to thisI'm not convinced and neither are the scientists it seems. In fact the whole idea is filled with words like may, possibility, seems, appears etc.
Reply | Report Abuse | Link to thisI'm concerned that no one seems to have researched what the LONG TERM effects would be. What effect will the carbon have on the dirt under our feet and all that depends on it?
And I'm concerned that instead of changing our habits, we're simply looking more for ways to hide the problem - put it somewhere else and maybe they won't notice but keep on producing as much as you like!
Is it not enough that we have poisened the air that we now feel the need to poison the earth?
I'm not convinced and neither are the scientists it seems. In fact the whole idea is filled with words like may, possibility, seems, appears etc.
Reply | Report Abuse | Link to thisI'm concerned that no one seems to have researched what the LONG TERM effects would be. What effect will the carbon have on the dirt under our feet and all that depends on it?
And I'm concerned that instead of changing our habits, we're simply looking more for ways to hide the problem - put it somewhere else and maybe they won't notice but keep on producing as much as you like!
Is it not enough that we have poisened the air that we now feel the need to poison the earth?
I'm not convinced and neither are the scientists it seems. In fact the whole idea is filled with words like may, possibility, seems, appears etc.
Reply | Report Abuse | Link to thisI'm concerned that no one seems to have researched what the LONG TERM effects would be. What effect will the carbon have on the dirt under our feet and all that depends on it?
And I'm concerned that instead of changing our habits, we're simply looking more for ways to hide the problem - put it somewhere else and maybe they won't notice but keep on producing as much as you like!
Is it not enough that we have poisened the air that we now feel the need to poison the earth?
I'm not a scientist but come on!!! If there are massive quakes or even one huge one, what is to stop the release of the carbon all at once? What if some fool company somehow unplugs or drills a hole in the containment rock?
Reply | Report Abuse | Link to thisAnd how about in the future when some new kind of mini sub goes underwater and unknowingly taps a hole in the rock. That is as stupid as Nuclear Energy. It's more polluting than any other form of energy and it lasts years longer. Imagine if the same quake hit the place where they are storing this stuff??? Kiss your buttox goodby. And if we keep up with oil and coal we'll only have carbon products to breath if we don't have the sun cook us and blow the earth up first.