ANCHORAGE, Alaska — The U.S. Department of Energy is soliciting for another round of research into methane hydrates, the potentially huge energy source of "frozen gas" that could step in for shortages of other fossil fuels.
The department is looking for research projects on the North Slope of Alaska that could explore how to economically extract the gas locked in ice far below the Earth's surface.
DOE is also seeking researchers to document methane hydrate deposits in outer continental shelf waters of coastal states.
The DOE anticipates federal funding of $20 million over two years that could be leveraged into research costing $80 million, according to its "funding opportunity announcement." The department could award money for both methane hydrate extraction research and for documentation or just one of those two research areas, according to the announcement.
A spokeswoman for the DOE's National Energy Technology Laboratory, Shelley Martin, said the department could not comment on funding opportunities while they are open.
Methane is the main ingredient of natural gas. It comes from buried organic matter after it's ingested by bacteria or heated and cooked. The gas migrates upward, under high pressure and low temperature, and can combine with water to form methane hydrate.
The DOE describes methane hydrate as a lattice of ice that traps the molecules but does not bind them chemically. Methane is released when the combination of ice and gas is warmed or depressurized.
Deposits can be found under permafrost in Alaska. For extraction research, such landlocked reservoirs provide a stable platform. Larger methane hydrate deposits can be found in sediment below the sea floor.
A Minerals Management Service study in 2008 estimated methane hydrate resources in the northern Gulf of Mexico at 21,000 trillion cubic feet, or 100 times current U.S. reserves of natural gas. The combined energy content of methane hydrate may exceed all other known fossil fuels, according to the DOE.
The department calls methane a clean-burning fuel and an important bridge to a time when non-carbon sources will supply more of the nation's energy supply. Since no one has figured out the extraction puzzle, it's uncertain exactly how it could be used.
Critics say burning methane will exacerbate the world's greenhouse gas problem and contribute to warming. Unburned methane released into the atmosphere is 20 times more effective at trapping heat in the atmosphere than CO2 but not as long-lived.
DOE has funded previous methane hydrate research.
The department and industry partners Houston-based ConocoPhillips and Japan Oil, Gas and Metals National Corp. drilled into a methane hydrate deposit over two Alaska winters ending in spring 2012 in a nearly $29 million extraction experiment.
The research was an application of laboratory studies done by ConocoPhillips and the University of Bergen in Norway indicating that carbon dioxide molecules injected into methane hydrate could swap placed with methane molecules, freeing methane to be harvested. The goal was extraction without compromising the integrity of the below-ground ice.
The experiment in 30 days of production captured nearly 1 million cubic feet of methane. Researchers concluded that a sizeable portion of the injected gas interacted with the methane hydrate.
The objective of the new DOE solicitation is to stimulate research that industry is not likely to pursue on its own accord in next two to three years.
In Alaska, the department wants field studies to evaluate extended response of methane accumulations to destabilization by lowering the pressure or other approaches.
The "marine hydrate characterization" solicitation is looking for field programs that will collect data and samples such as drilling cores.
Applications are due May 22.