In the future, natural gas derived from frozen methane-based hydrates extracted from the ocean floor and beneath the Arctic permafrost may fuel cars, heat homes and power industry, according to the American Chemical Society.
US government researchers say that gas hydrates are showing increasing promise as an abundant untapped source of clean, sustainable energy.
Despite fears of uncontrolled gas-hydrate releases as a result of global warming, they say this source of methane could supplement traditional energy sources that are in short supply and which produce large amounts of carbon dioxide linked to global warming.
“These gas hydrates could serve as a bridge to our energy future until cleaner fuel sources, such as hydrogen and solar energy, are more fully realised,” says study co-leader Tim Collett, a research geologist with the US Geological Survey (USGS).
In November, 2008, a team of USGS researchers, which included Collett, announced a giant step toward that bridge to the future. In a landmark study, the USGS scientists estimated that 85.4trillion cu ft of natural gas could potentially be extracted from gas hydrates in Alaska’s North Slope region, enough to heat more than 100million “average” North American homes for more than a decade.
In 2006, the Mount Elbert prospect well was drilled from an ice pad constructed to protect the sensitive Alaskan Arctic tundra. The well was designed to verify the nature of one of 12 gas-hydrate accumulations previously identified by the project within the Milne Point unit of the greater Prudhoe Bay region of Alaska’s North Slope.
The project was a joint effort of the US Office of Fossil Energy’s National Energy Technology Laboratory (NETL), the USGS, BP, the Alaska native-owned Arctic Slope Regional Corporation, the Universities of Arizona and Alaska (Fairbanks), and others.
“It’s definitely a vast storehouse of energy,” Collett says.
“But it is still unknown how much of this volume can actually be produced on an industrial scale.”
That volume, he says, depends on the ability of scientists to extract useful methane, the main ingredient in natural gas, from gas-hydrate formations in an efficient and cost-effective manner.
Scientists worldwide are now doing research on gas hydrates in order to understand how this strange material forms and how it might be used to supplement coal, oil and traditional natural gas.
Although oilmen and scientists have known about gas hydrates for decades, they have only recently begun to try to use them as an alternative energy source.
Gas hydrates, also known as “clathrates,” form when methane gas from the decomposition of organic material comes into contact with water at low temperatures and high pressures.
Those cold, high-pressure conditions exist deep below the oceans and underground on land in certain parts of the world, including the ocean floor and permafrost areas of the Arctic. They are sometimes released during drilling operations and can be very dangerous as a result.
Today, researchers are finding tremendous stores of gas hydrates throughout the world, including US states, India, Taiwan and Japan.
One of the more promising techniques for extracting methane from hydrates involves simply de-pressurising the deposits.
Another method involves exchanging the methane molecules in the “clathrate” structure with carbon dioxide. In theory, it should be possible to mine the resource using the same drilling technology used for conventional oil&gas drilling.