Screenshot of burning methane hydrate courtesy of the USGS via YouTube.
Buried thousands of feet under sea level, methane hydrate is a potential carbon fuel that holds more energy than all fossil fuels – but also potentially massive greenhouse gas emissions.
Informally called “fire ice,” gas hydrates are solid, ice-like chunks containing energy-intensive methane gas. This gas can be set on fire (hence the name), or used for energy.
Skip to 4:05 to see the ice burning:
It’s created when organic sediments on the ocean floor release methane, which reacts with water to create a crystalline structure.
This only occurs at ocean depths of 1,600 feet or more, in coastal areas where temperatures are low but the water pressure is high. Some deposits are also found under the permafrost in the Arctic circle.
Fire ice is potentially extremely energy-efficient. While a process of extracting it has yet to be commercialized, the material is known to be able to hold up to 160 times its volume in methane.
Where can fire ice be found?
There’s considered to be an immense quantity of methane hydrate deposited around the world – more available energy than all other fossil fuels on Earth combined, according to the U.S. Geological Survey (USGS).
The following map shows locations where methane hydrate has either already been recovered, or believed to exist:
Image courtesy of the USGS.
Why has no one exploited this resource yet?
While it was discovered in the ‘60s, it wasn’t seriously being researched as an energy source until the ‘90s, according to the USGS.
Obviously, merely accessing the deposits several thousands of feet below sea level is difficult.
But it’s further complicated by the fact that the sediments form in a porous sea bed, creating risks of submarine slumping and landslides as material is extracted.
It’s also technically challenging to separate the gas from the hydrates.
Using current methods, it would have to be pumped out using a continuous stream of water to alleviate the pressure. The methane hydrate would also have to be heated at the source because extracting the gas cools the sediments, which can halt the process.
So far, a method of extracting the methane that uses less energy than it extracts has yet to be found, although scientists have come close.
Japan in particular has shown an interest in the fuel, seeing it as a potential solution to its dependence on foreign energy. So far, it has spent more than $700 million on the project; in comparison, the U.S. has only spent $25 million.
How would fire ice impact the environment?
Methane hydrate is often compared to fracking: they are both enabled by technological advances, and allow companies to take advantage of previously inaccessible resources.
They also both extract methane gas, which becomes the greenhouse gas carbon dioxide when burnt, but is much more efficient than burning coal or oil.
Methane itself, however, has advocates worried. It’s a powerful greenhouse gas – while its half-life is much shorter than carbon dioxide, it’s show to be as much as 30 times more potent.
There’s even speculation that a massive release of methane was responsible for an extinction event that almost wiped out all life on Earth 20 million years before the first dinosaurs appeared.
According to the USGS, such an event is unlikely to happen – only 5% of the world’s methane hydrate deposits would spontaneously release the gas, and most of it would be absorbed by the ocean before it reaches the atmosphere.
One experimental method of extraction could even help offset any emissions by using CO2 to extract the material, essentially trading places with it inside of the ice cage.
Of course, this is a young field of science, and there’s no broad consensus on what impact fire ice will have on the environment. The technology and infrastructure for commercial production is still years away – and some hope that by the time it arrives, we will be well on our way to reducing our dependence on fossil fuels.