[enahs]

I suspect methane hydrates would be the next logical choice, and might even being to be used before fossil fuel is used up.

[Donaldson Tan]

Many parts of the world are currently exploring options of using carbon dioxide for Enhanced Oil Recovery and Enhanced Coal Bed Methane Recovery. Both are proven technologies that are used extensively in the United States. Only thing I can't seem to find in literature is whether the carbon content pumped into these fossil fuel reservoirs is actually more or less than the carbon content being pumped out. This is important from a sustainable point of view.

Where can we find methane hydrates? Why isn't this energy source previously exploited?

[enahs]

Where can we find methane hydrates? Why isn't this energy source previously exploited?

The current largest known methane hydrate deposits are in the ocean floor. This is also why we have not exploited it yet, because the cost of obtaining them are very high. But as tradition fossil fuel prices rise, it might be economical to start "mining for methane hydrate". And as technology and tools have gotten better, the cost of this process is also drop.

There is also potential for greatly disrupting the oceans, which is a major concern, especially if you try and start using it as a primary source of fuel.


The estimates on the amount of oceanic methane hydrate deposits has varied greatly over the past 10 or so years. I have seen reports claiming as much as 100 times more then all the fossil fuel known to exist and have existed, to the now general estimate of ~5X more then the natural gas deposits.

This article is a little old but a kind of a ok quickie intro:
http://www.ornl.gov/info/reporter/no16/methane.htm
And Japan is currently doing a experimental endeavor with methane hydrates
http://www.mh21japan.gr.jp/english/mh21/02keii.html

Though this site is probably the most in depth:
http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/maincontent.htm
Pay special attention to the menu on the right.



The reason I suspect that this would be the next choice for a new energy source is because we already have an infrastructure and knowledge of how to deal with methane (natural gas is primarily methane). Of all the other potential sources for energy, a major concern will be the ease of switching over; as that is the most costly part of this. By tapping into a source we already have extensive knowledge and use tremendously (at least storage and transport wise, not necessarily refining), from a logical standpoint seems the cheapest and easiest.



If I knew my one line response was going to be turned into a new thread starter, I might have provided a little more information!   

[xiankai]

i have a friend who did methane clathrates for his project. (he calls them clathrates instead of hydrates, no idea. but its essentially the same thing i can guarantee)

i interviewed him abit and he was happy to supply me with his thesis, which unfortunately is in german. i hear also that the russians are mining for it in permafrost regions in siberia, which means that extraction of them may not necessarily focus on the ocean floor, although exploitation of ice regions could lead to them being further destabilized, especially with global warming melting the polar caps and thus causing rising sea levels.

http://www.baum.org/projekt/dokumentation.pdf

also if anything, an article in scientific american (volume 281, number 5, november 1999) has an article about the substance, and i gather that the Research Center for Marine Geosciences (GEOMAR) is at the forefront of developments; some technical data can be found at their site:

http://www.ifm-geomar.de/index.php?id=1234&L=1
http://www.ifm-geomar.de/index.php?id=1230&L=1

there's an english and german translation, as one can see at the top.

[eugenedakin]

I have worked alot with clathrates, and they are currently being produced (knowingly and unknowingly) in some Canadian oil wells. Pressure, moisture and natural gas forms hydrates.

Lower the pressure or increase the temperature causes the methane to be produced and the water to remain down hole.

Just my $0.02.

Sincerely,

Eugene