Fire in ice: LANL's quest for energy
People who expect science to solve world problems with a nifty new set of discoveries may have something to cheer about soon.
Wouldn't it be great, for example, if there were some sign of relief on the energy front that might also address what appears to be a looming crisis of global warming?
Those who haven't heard of clathrates, gas hydrates or methane hydrates may be in for a surprise.
A $4 million, three-year project at Los Alamos National Laboratory is examining clathrates from the inside out and from outside back in again.
The object is to understand the behavior, composition and utility of these fascinating little packages.
A clathrate is a cage-like structure formed from a water molecule. Under a combination of high pressure and low temperature, clathrates trap gas molecules of methane in permafrost and on the floor of the ocean along continental shelves.
Under another combination, principal investigator Yusheng Zhao said clathrates can trap hydrogen, at high levels of concentration.
Hydrogen is now typically stored in liquid form, which takes very low temperatures and extremely strong containment or it will blow up.
Hydrogen clathrates can store hydrogen at ambient temperatures, addressing one of the major roadblocks to a hydrogen economy of the future.
Zhao and colleagues are on a laboratory fast track for a patent for the rapid formation of hydrogen clathrates.
Under a different combination, Zhao said, clathrates might also be used to capture carbon dioxide. Taking carbon out of the atmosphere and locking it away in little cages, a process called sequestration, would take a load of trouble out of the atmosphere.
By far the most famous clathrates are known as methane hydrates, or as action-adventure novelist Clive Cussler calls them in his 2002 thriller, "Fire Ice."
"Looks like icy snow, only it's flammable," explains one of Cussler's characters. "It could be worth trillions, which is why so many people are interested in its extraction."Methane hydrates have begun to command increasing attention from geologists and the energy industry because of their sheer volume as an energy resource.
A standard estimate is that the energy contained in methane hydrates is about twice as much as all other gas, oil and coal combined. Among many complications for harvesting methane hydrates, however, is that they tend to be hard to find in concentrated amounts and even harder to collect.
On Sept. 21-22 the Department of Energy's Methane Hydrate Advisory Committee will be meeting in La Jolla, Calif.
The committee will be developing recommendations and setting priorities for DOE's research program.
In a telephone interview this week, Edith Allison, DOE's program manager for methane hydrates, said a five-year congressionally authorized research program to study the resource would expire next year.
"So this is an interesting time, as we expect Congress to consider whether and what will continue and at what level of funding," Allison said.
"In five years we've accomplished some exciting things. We've brought this from science fiction to a resource that has potential."
Part of the process has been to map and survey the global reservoir of methane hydrates. Allison said the "gas in place" is estimated to be 300,000 trillion cubic feet (tcf).
By comparison, she said, "We use 22 tcf each year, and we have 1,400 tcf of conventional resources," but only a very small portion of the known quantities of methane hydrates will ever be used because most of it is so dispersed.
Late last year, promising results were reported from test wells in the Mackenzie Delta of the Northwest Territories of Canada, an international consortium that involved DOE and the U.S. Geological Survey.
Although there remains much to learn about these peculiar deposits, the USGS reported that the tests "demonstrated that gas can be produced from gas hydrates."
"We're projecting commercial production between 2015 and 2020," Allison said, who compared the resource to coal bed methane, which was once considered an oddity, but now accounts for 7 percent of domestic gas production.
Next spring, Allison said, a joint industry project headed by Chevron and Texaco will begin drilling core samples in the Gulf of Mexico, where a conventional oil and gas production network already exists.
"Discoveries of exploitable deposits of methane hydrates there," she said, "would mean that as conventional gas fields decline, the hydrates could be introduced as a supplement."
Another action item for DOE's advisory committee will be to submit a report to Congress on a new and potentially apocalyptic problem associated with methane hydrates, the dark side - their apparently underestimated ability to dissolve, bubble up and possibly vent into the atmosphere.
Methane hydrates, have been offered as a scientific explanation for the shipwrecks of the Bermuda Triangle, although perhaps not conclusively.
More seriously, they are blamed for a sudden global warming event 55 million years ago that led to massive extinctions of mammals.
That's when Rice geologist Gerald Dickens, has dated a disruption of gas hydrates that raised the earth's temperature by 7 degrees.
Considering that methane hydrates are released as water temperatures rise, they are a major new ingredient in studies of the global carbon cycle and may be even harder than human emissions to control.
"We thought we had a good handle on global impacts related to carbon," said Barbara Moore, director of national undersea research program at the National Oceanic and Atmospheric Administration in Maryland, "but a natural resources plan that came out a few years ago didn't even mention hydrates."
LANL's program feeds into all these aspects of ongoing research, Zhao said.
The investigation that he oversees at the Los Alamos Neutron Scattering Center uses neutron diffraction to peer into the crystalline structure of the clathrate, to examine its kinetic structure, how it forms and decomposes.
A second thrust, led by Don Hickmont in earth sciences and Lawrence Pratt in modeling, uses the data from the neutron diffraction as parameters to understand how methane hydrates can be stabilized and transported under the natural conditions of the ocean floor.
Robert Currier, a chemical engineer, studies the gas hydrate as a resource and the clathrate structure as a container for sequestering greenhouse gasses.
LANL research will also provide a foundation for locating gas hydrates, by using ultrasonics to identify gas hydrate sediments.
"What we are doing here will provide industry people the fundamental data at the ocean floor that will contribute to future exploration," Zhao said.
ROGER SNODGRASS, roger@lamonitor.com, Monitor Assistant Editor
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