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March 15, 2005
Mining the Oceans' Natural Gas
Below the ocean floor lies a vast reserve of frozen natural gas--200,000 trillion cubic feet, geologists estimate. The big question is--could this be the clean and abundant fuel source we've been searching for?
Since the 1970s, researchers have been intrigued by methane hydrates, mysterious deposits of natural gas that hold promise as a sustainable energy resource. The problem was that very little was known about these crystalline solids--where they could be found, how plentiful they were, and how to extract them. As a result, their true potential remained shrouded in mystery.
Not anymore. According to a February 2005 Mechanical Engineering magazine article, dedicated research programs in the U.S. and around the world are uncovering many answers. Encouragingly, they suggest that the "commercial production of methane from hydrate may now be just around the corner," says the article. It reports that through field studies in places such as the waters off Oregon, the Gulf of Mexico, and the Alaskan North Slope, it's become evident that tapping into the methane in these solids is both "technically feasible and economically viable." And it can be done with current technologies. In fact, in Alaska, geologists are already plotting out ways to commercially produce methane from the hydrates they have spotted.
What's more, the vastness of this potential resource has been backed up by data. Ten years ago, the U.S. Geological Survey was the first to systematically quantify the methane volumes in hydrates in the U.S. and bounding continental shelves. Now, integrating the latest data, geologists place that estimate at 200,000 trillion cubic feet, which is equivalent to about 2,000 times the current amount of energy the U.S. consumes in a year. Global estimates, meanwhile, vary by several orders of magnitude, due to remaining uncertainties. However, even by the most conservative figures, gas-in-place volumes in methane hydrates are said to be 10 times greater than all recoverable natural gas in the world.
Article author Ray Boswell, technology manager for methane hydrates at the U.S. Department of Energy's National Energy Technology Laboratory, points out that the viable production of methane from these hydrates will help ensure the "long-term supply of natural gas, an environmentally friendly fuel with enormous economic and energy security benefits to the nation."
These frozen undersea deposits of natural gas are exceedingly difficult to study, however. Found in marine sediments and in the Arctic, they melt at room temperature at sea level, dissociating into water and methane. (Methane hydrate is a solid substance, in which host water molecules trap methane molecules without bonding them.) Thus, specialized equipment, such as pressure-retaining containers, and sophisticated technologies, such as computed tomography X-ray scanning and nuclear magnetic resonance imaging, are a must in the study of methane hydrates.
According to Mechanical Engineering, "the promise of methane hydrate is this: It is a very efficient storehouse of energy. When dissociated, a single cubic foot of solid hydrate releases as much as 180 cubic feet of methane gas." In methane hydrates, the natural gas is trapped solid within.
Now the tough part is figuring out how to competitively mine this resource. They reside after all in tough-to-reach low temperature-high pressure settings, in particular in sediments under some 500 meters or more of water and in some Arctic continental areas. Deep-water operations obviously will not come cheap. What's more, the environmental implications of exploiting these deposits still have to be explored.
Mechanical Engineering poses the question, "Will methane hydrate fuel the future?" The answer seems to be "we'll see"--researchers still have to figure out how much producible methane there is in these frozen deposits.
Source:
Buried Treasure
Ray Boswell
Mechanical Engineering "Power & Energy," February 2005
www.memagazine.org/pefeb05/buriedt/buriedt.html
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Comment
17 CommentsGreat article. Need more information on the subject.
March 15, 2005 4:43 PMGeorge, for more information on methane hydrates, check out...
http://marine.usgs.gov/fact-sheets/gas-hydrates/title.html
http://www.netl.doe.gov/scngo/Natural%20Gas/hydrates/
http://www.llnl.gov/str/Durham.html
Thanks for your feedback.
March 15, 2005 4:49 PMVery interesting reading. I have forwarded to my friends for updating them on the subject.
By the way what are the HSE issues while going for exploitation of the Gas Hydrate. I am concerned for the same.
Thank you.
Nath, J D
If the enviromentalists have their way, those reserves might as well be on Jupiter. In spite of our voracious appetite for fossil fuels on Long Island and in the Northeast in general the NIMBYites are once again asking us to consider completely impractical options for travelling and generating electricity in our area. I think they should find themselves a new backyard and try proposing 3 solutions for every problem they conjure up in their silly little minds.
March 16, 2005 3:36 PMMethane hydrates and methane in the deep oceans will challenge us for some time, first to understand the resource and the myriad opportunities, problems and dangers. I think too much of the research work and thinking on extraction is stuck on the big oil models.
I have run successful tests on methane extraction from deep water using far simpler technologies in Africa, on a low budget basis and produced a continuous stream of medium pressure methane. The new concept works safely and will provide one country's entire power needs on a cheap and sustainable basis for at least the next thousand years. The same can work in the more hostile oceans in future with some upgrading of the systems. It is "out of the box" thinking, but then that is what I believe is necessary to break out of the existing thinking.
July 29, 2005 8:01 AMIt's a case of problem meets anti-problem. Methane is a potent greenhouse gas. We need a lot of clean energy. We can and we should find a way of using the methane from hydrates before it endangers us.
I was encouraged to read the comment of Philip Morkel (July 29, 2005). The more people tackle the puzzle of recovering methane from methane hydrates, the more likely we are to have an elegant, clean, relatively cheap solution in short order.
In much of the industrialized world, the infrastructure for delivery of natural gas is already in place. For generating energy from methane we could use fuel cells, which produce about 56% of the carbon dioxide combustion energy generation does. Fuel cells are proven technology. As long as a town or a campus or a hospital or shopping mall had a supply of methane,
it could generate its own clean energy. We could sidestep Enron type manipulations.
Reforming methane, that is, removing its hydrogen atoms, is also an old technology. Metal hydrides store hydrogen safely. Metal hydrides got a lot of attention when people hoped they could store hydrogen to generate power for automobiles, but the weight was prohibitive for that purpose. However, such a weight/energy ratio would not be prohibitive for locomotives. If there was a lot of cheap hydrogen (from lots of cheap methane) then rail transport using hydrogen in fuel cells for fuel, would become attractive for both economic and environmental reasons.
I am a little surprised that environmentalists would object to methane hydrate research, since using methane as fuel because it would neutralize
methane as a greenhouse gas, supplant coal, and provide energy independence.
environmentalists taken to their logical outcome don't want energy independence, they want mother gaia depopulated.
October 6, 2005 1:56 PMI've managed to save up roughly $81608 in my bank account, but I'm not sure if I should buy a house or not. Do you think the market is stable or do you think that home prices will decrease by a lot?
November 14, 2005 1:32 PMWhat if methane hydrates are a means by which the planet rewarms itself in the event of an ice age? If there is an ice age, the ocean level drops. When the level drops too far methane hydrate relseases methane. Due to the fact that methane hydrate only exists below 500 meters or so. When the ocean level drops the pressure on existing methane hydrate drops and methane is released. If methane is a green house gas and large amounts warm the planet. The existance of such a resource could be a means to this end. Keeping the planet's temrature in check.
March 22, 2008 10:16 AM
