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Storing Liquid CO2 in the Oceans?
Roland Piquepaille writes "One of the ways to reduce greenhouse gas emissions is to capture carbon dioxide at its source, when it is emitted from power plants for example, and to store it in other places, such as depleted oil and gas reservoirs or even the ocean after liquefaction. But, according to Youxue Zhang, a professor at the University of Michigan, there are pitfalls in this last plan. If the carbon dioxide is not injected deep enough, it can come back to the surface and return to the atmosphere, which is obviously not the desired goal. But, even worse, the liquid-to-gas conversion could happen too suddenly, which could cause a potentially dangerous eruption. So Zhang has developed a model which shows that liquid CO2 would have to be injected to a depth of between 800 and 3,000 meters to keep it from escaping from the ocean."
And this site kindly points out the following:
Not to mention the environmental effect of millions of farting & belching sea creatures. I think we should keep a close eye on this man :)
Modest doubt is called the beacon of the wise. - William Shakespeare
Here is the Link to the story I was talking about.
DEAD DEAD DEAD DELETE ME
In addition to allowing CO2 to recombine with the system in a more natural way (next to the O2 in the water that makes up the C), this offers the side benefit of transforming ocean life dumb enough to swim through the layer to freezer-ready seafood.
However, it is important to note that fluidic injection of a medium density liquid between two light density liquids is neither the safest nor most effective method of obtaining a clearly-delineated stack. Anyone who has mixed a layered drink will tell you that you go from highest density to lowest density, pouring each layer of liquor against a spoon so as to prevent gravity from making an environmental disaster of your nightcap. Pumping liquid CO2 into the sea thus begs the question of what sort of sludge should go under it to replace the water (and where to find a spoon that large.)
Try not. Do or do not, there is no try.
-- Dr. Spock, stardate 2822-3.
I believe something like that was shown on BBC Science and Nature. The show title was "Killer Lakes".
a kes.shtml
The theory is indeed about having large amounts of CO2 trapped at the bottom of a body of water. When its disturbed, the CO2 escapes to the surface, and being quite a dense gas kills quite a number of O2-loving lifeforms through suffocation.
http://www.bbc.co.uk/science/horizon/2001/killerl
It could be an uber doom chemical if, you know, you have gills that extract oxygen from the water so you can breathe. Replace said oxygen with liquid carbon dioxide and voila, instant undersea holocaust.
Worst. Science. Idea. Ever.
At the concentrations typically found in seawater, the concentration of oxygen and carbon dioxide are independent of each other. A very high concentration of carbon dioxide could reduce the solubility of oxygen in the water, but at that point the drastically reduced pH would likely have caused other problems.
Anyway, I was going for tongue in cheek ;)
Modest doubt is called the beacon of the wise. - William Shakespeare
There are several lakes in equatorial Africa which by virtue of their depth and location sequester large amounts of carbon dioxide gas in solution and create a potentially dangerous situation. The incident to which you refer occurred at Lake Nyos in the Northwest Province of Cameroon on the 21st of August 1986. The lake emitted a large cloud of CO2 gas when the waters of the lake were disturbed by an underwater landslide and the gas bubbled up from the depths of the lake. The resulting cloud of gas flowed down the hillside and through the surrounding areas killing 1,800 people and 3,500 livestock. Degassing pipes have since been installed at Nyos and other similar lakes to allow the stored gas to be gradually released from solution and thereby prevent another uncontrolled release.
Please mod this UP. CO2 *will* mess with the pH and could possibly cause plant life to grow like crazy. Read about CO2 injectors that people use in their aquariums and why they use it (and the pitfalls of using CO2 injectors with live fish)
What the AC is talking about is a situation like this:
At high pressures (great depths) CO2 will remain in solution. All is well. However, if conditions change, this CO2 can suddenly release to the surface killing animals/people.
look at this for more info on how deadly it can be
This normally isn't a problem with lakes because of the temperature change with the seasons cause the water to cycle, and CO2 on the bottom will be released subsequently. (This happens because water density changes with temp, and if the top layer is denser than the bottom layer, it will sink and the bottom layer will rise.)
Now, when the water doesn't cycle because the surface temp doesn't change- such as near the equator, CO2 buildup can reach extremely high levels. Thus, when the CO2 is released, it's a deadly concentration.
The fear is that if the oceans suddenly change and CO2 will be released making deadly concentrations.
Grump
Univ. of Calif. Riverside,
Environmental Sciences (senior)
Is it true that more people vote for the winner of American Idol, than vote for the president? -Ali G.
I do geophysical research on marine methane gas hydrates and have read a great deal about them.
;) Mine the hydrates, use them in your fuel cell cars, which are pollution free! Sounds great, but we are decades away from that - if ever. There are massive roadblocks to mining marine hydrates. Slope stability is just one of them. Its low key, but the oil industry is interested in gas hydrate.
I see a few flaws in your argument that using the ocean as a CO2 sink would cause sudden dissociation of gas hydrates.
-Generally the highest conecntration of gas hydrates in the the base of the stability zone, which is typically 300 or so metres below the seafloor (this depends mainly on water depth). The base of this zone is where the hydrate would first dissociate from a change in temperature or pressure - not the top. There is no way for much if any bottom water CO2 to reach this depth in the sediment.
-Gas hydrates are sensitive to a change in pressure or temperature. This is why a drop in sealevel _may_ cause release of gas from hydrate deposits. To a lesser extend salinity will affect the stability of hydrates. Hydrates are clathrates of water host molecules surrouning a methane guest molecule. I have never heard that CO2 will cause a change in hydrate stability - but I'm not a chemist.
So personally I doubt hydrates would be affected by CO2 levels, but I also think its a terrible idea to use the ocean as a CO2 sink.
Most of these suggestions I have heard relate to injection of CO2 into the ocean, and stimulating the growth of organisms with carbonate shells such as most types of zooplankton. The idea is that carbon will be consumed by the creation of these calcium carbonate shells, and collect into carbonate rich sediments which accumulate and get buried (lithified, etc) - thus removed from the carbon cycle (at least temporarily, on a geological time scale).
From my perspective it seems nuts to burn fossil fuels, and try to return the CO2 produced back to the sediment - via the ocean. It makes much more sense to avoid releasing all this CO2 in the first place. But thats where hydrates come in
There are also methane gas hydrates that form in many of the permafrost regions of the world. Mallik is a project by the Geological Survey of Canada that has managed to drill and extract methane from a hydrate deposit and even flared some of the gas. This proves its possible to mine - at least from permafrost hydrates.
Cheers,
Chris
Well, to quote from actual Science (well, at least the magazine):
The relatively modest increase in carbon export does not appear to be large enough to make iron fertilization a viable method for sequestering anthropogenic CO2, however.
This Week in Science
The full paper reference is:
Robotic Observations of Enhanced Carbon Biomass and Export at 55S During SOFeX
James K. B. Bishop, Todd J. Wood, Russ E. Davis, Jeffrey T. Sherman
Science, Vol 304, Issue 5669, 417-420 , 16 April 2004
> Stick a metal fork/spoon into a cup of coke for a week and see what happens. ;)
After hearing rumours of the extreme acidity of coca-cola I did just that, with various objects. The copper ones came out cleaner looking, the others weren't visibly affected, including a tooth
(everyone, if you hear urban legend bullshit like this and it's safe to try it to see for yourself, go do so. There's a lot of misinformation floating around)
Nothing happens to the fork.
Now, HOW strong is the acid in your stomach compared to carbonic acid in coke? mmmK?
And the people shall be oppressed, every one by another, and every one by his neighbour Isaiah 3:5
You also don't really want to encourage that much plankton growth, as many phytoplankton produce volatile halocarbons. Feed the weeds, reduce the CO2, and blow a hole in the ozone layer you'll never forget. There's another Science article from around 1999-2000 discussing metals in marine systems, which mentions that the biogenic halocarbon production is approximately equal to anthropogenic sources.
The obvious answer is to eat more sushi, and get that Nori under control.
the more accurate the calculations became, the more the concepts tended to vanish into thin air. R. S. Mulliken