Storing Carbon Dioxide under the OceanA safe, high-capacity method could make carbon sequestration more practical.
One way to combat global climate change is to directly capture carbon dioxide, the main greenhouse gas, as it is being emitted, and store it safely. But methods of carbon dioxide sequestration, notably, pumping the gas into underground geologic structures such as exhausted oil reservoirs, are not practical in many areas, and raise fears that the stored carbon dioxide will escape.
Now researchers at Harvard University and Columbia University have proposed a new method for trapping nearly limitless amounts of carbon dioxide -- a technique they say will be secure, as well as a practical option for areas located far from underground reservoirs. The researchers, in an article posted online this week in the Proceedings of the National Academy of Sciences, propose that carbon dioxide be pumped into the porous sediment a few hundred meters into the sea floor in deep parts of the ocean (greater than 3,000 meters deep), in what one of the researchers, Dan Schrag, professor of geochemistry at Harvard, calls "a fairly simple, permanent solution." The key was finding a "sweet spot," where the pressure and temperature of the surrounding environment make carbon dioxide more dense than surrounding fluids, thereby trapping it in place. This situation occurs at the bottom of the ocean because of a combination of high pressure and low temperatures -- a fact others have also noted in proposals to store carbon dioxide in deep parts of the ocean. But such injections would kill ocean life, and, unless sequestered in deep trenches, the carbon dioxide could be carried by currents to shallow areas, where it could reenter the atmosphere. The researchers' insight was that injections into the sea floor could take advantage of the pressure and temperature of the ocean, while avoiding the negative side effects of earlier proposals. The carbon dioxide, in liquid form, would be brought to the sequestration site by ship or pipeline, and piped into the sea floor with equipment like that used by the oil industry for drilling deep-sea wells. Once beneath the sea floor, the carbon dioxide would interact with the surrounding fluids and produce hydrate ice crystals, which would plug the rock pores, serving as a secondary cap on the carbon dioxide. Over hundreds of years, the carbon dioxide would dissolve in the surrounding water, and then would only have the potential of leaking out by diffusion, a slow process that would take millions of years, the researchers say. Within the next five years they hope to run a large-scale field test of this new approach. |
E-mail
Audio »
Print
Favorite
Share »
Digg this
Add to del.icio.us
Add to Reddit
Add to Facebook
Slashdot It!
Stumble It!
Add to Newsvine
Add to Connotea
Add to CiteUlike
Add to Furl
Googlize this
Add to Rojo
Add to MyWeb
Carbon Capture Remains Elusive
10/05/2009
Massachusetts Institute of Technology
Comments
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
At current levels of depletion of rain forest, and increasing production of carbon dioxide, we are burning (literally) the candle at both ends. Storage of CO2 will just defer the problem to future generations, while we continue our greenhouse gas emitting lifestyles!
08/08/2006
Posts:1
08/10/2006
Posts:1
08/12/2006
Posts:1
08/14/2006
Posts:1
08/14/2006
Posts:1
08/14/2006
Posts:1
08/08/2006
Posts:1
What about changing oceans currents pattern or vulcanic or seismic activity?
A sediments underwater landslide?
What happen if there is a release of some cubic Km near a big coastal city?
BP? Are the same claiming a big bug in their duct just yesterday?
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
Natural transformations are based mainly on chemical and/or biological processes that may be explained by the geochemical cycles, and some of these processes may be temporary and may need a period of time to transform the CO2, but chemical equilibrium and difussion that is related to mass transfer is always present even in the bottom of the ocean.
Second: Who can assure that this storage will be located in an area that is not affected by quakes?. Geology is a very important tool, but our knowledge about geological processes is still limited.
Third: The CO2 may not be enough to kill the earth, but it could be enought to affect the oceanic food chain, kill some of the aquatic life and probably kill some human beings present in the surrounding area.
08/08/2006
Posts:1
http://www.geology.sdsu.edu/how_volcanoes_work/Nyos.html
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
http://en.wikipedia.org/wiki/Grey_goo
08/08/2006
Posts:1
08/09/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
08/08/2006
Posts:1
08/09/2006
Posts:1
jamesdwms
08/24/2006
Posts:2
I was unable to find out the number, someone on this board has this info or link?
08/08/2006
Posts:1
08/09/2006
Posts:1
I agree with kitk that our knowledge about some of the characteristics of CO2 are poorly understood, that's why we need to work with it first, before we try to put the CO2 at the bottom of the ocean.
Remember what happened when one group of researchers injected liquid CO2 in the soil, this experiment created a lot of problems, even when they considered the chemical and biological principles known at that time.
08/09/2006
Posts:1
see http://www.technologyreview.com/read_article.aspx?id=16977&ch=nanotech&sc=&pg=2
Because pressure and cold makes luquid carbon dioxide heaver then water I'm not so worried about some of the concerns expressed so far except, potential acidification of the oceans, and a potential terrorist threat of heating the liquid carbon dioxide with an explosion of sorts.
Personally i wonder if the carbon can be removed from carbon dioxide and used to make plastics or carbon fibers composites or anything else, maybe more carbon nanotubes for other exciting new technologies i.e. space tethers or computing.
08/09/2006
Posts:1
because a lake in an old volcano
burped it's Co2 while the people
slept. There was footage of dead
people and animals. The children died first because they were closer
to the ground. I was in a factory
fire where a 'Cardox' system was
used instead of water, many people
lost counciousness and had to be
carried out. In Medias Res
08/09/2006
Posts:1
ps: future energy needs can only be met with nuclear energy.
08/09/2006
Posts:1
See, http://www.jamstec.go.jp/jamstec/MTD/Whale/
These are floating stations but I have also read about land based shoreline stations that could be carved into the rock walls as to not destroy the natural shoreline itself.
As for wind power I believe this technology should be left alone except for personal energy consumption. The amount of wind-towers required for mass scale energy production is phenominal. We(mankind) already have cleared too much land for our own use.
Lastly keep the oil companies away from any research. Any. That includes taking and using their money! Absolute power corupts absolutely! So does $$$ Cash!!!
Astron
01/19/2007
Posts:1