The "Burning" Ice - Methane Hydrate.

The burning Methane Hydrate.

What will happen if you increase the temperature of an ice? Yes, it will melts. However, there is a type of ice, which we called as “fire ice”, will not melts if you increase the temperature. In fact, it will burn if it meets a lit match!

So, what is this fire ice? The fire ice is actually the methane hydrate. Methane hydrates belong to a group of substances called chathrates. Chathrates are the substances where one type of molecule formed a cage-like lattice structure while another type of molecule is enclosed by it. In this case, the cage-forming molecule is water which represents the “hydrate” while the “methane” gas is trapped inside. As a result, the compound is known as “methane hydrate”.

Formation of  Methane Hydrate

Types of Methane Hydrate Deposits

Huge amounts of methane around the world under the deep ocean sea beds and vast swathes of permafrost. The formation of methane hydrates required specific physical, chemical and geological conditions. The best condition for the formation of methane hydrates are high water pressure and low temperature. When the sea water temperature is warm, great water depth is required to produce high pressure so that water molecules can be pressed into a chathrate cage. However, there are no methane hydrate can be found in the deepest ocean regions although they have the highest pressure. This is because there is very little methane available here and the high temperature of the Earth’s internal heat. On the other side, when the sea water temperature is very low, methane hydrates can conceivably formed in swallower water depth, such as continental slopes or on the land in permafrost. Usually, in these areas, there are sufficient organic matters accumulating on the bottom to produce methane and the combination of temperature and pressure is very favourable for the formation of methane hydrates. 

"Methane Escape"

Today, global warming had become the main issue of environment. Global warming, which include the warming of ocean, may disturb the stability of methane hydrates. As we all know, methane is also a greenhouse gas. Recent studies show that methane gas is 30 times more damaging than carbon dioxide gas. As global temperature continues to rise, the sea water temperature will increases and the permafrost will melts. Thus, the enormous reserves of methane which trapped inside the ice will be released to the surrounding, which further increases the temperature of earth. The mainly affected areas are in the open ocean at around 500 metres of water depth as well as in the shallow regions of the Arctic permafrost.  “Methane escape” could be a catastrophic circular reaction because the release of even a small percentage of methane gas from total deposits of methane hydrates could give a serious effect on Earth's atmosphere. It is estimated with a steady warming of the sea water of 3 degrees Celsius, around 85% of the methane trapped in the sea floor could be released. Besides, “Metane escape” also reduces the stability of sea floor. Methane hydrates are one of the compounds which filled the pores between fine sediment particles and stabilizes the sea floor. If more and more methane hydrates escape, the sea floor become unstable due to missing cement. Large parts of continental margins may fail. Sometimes, submarine landslides and tsunamis may also occur in the worst case. 

Melting permafrost released the methane trapped inside the ice.

Future of Methane Hydrate

Many researches had been carried out to investigate the stability of methane hydrates in dependence of temperature fluctuations and also the action of methane after it is released. Since it is impossible to prevent the breakdown of methane hydrates and release of methane gas, some researchers try to explore the possibility of a reverse relationship. We know that methane is the chief constituent of natural gas. In methane hydrates, there are more energy than the other fuel source in the world such as oil, coal and gas. One cubic meter of methane hydrate can releases about 160 cubic meters of methane gas. So, a lot of energy can be released from methane by just breaking down the methane hydrate into water and methane. Methane is the most important gas that makes methane hydrate as the highly energy-intensive fuel source.

The huge amount of methane hydrates found around the world represents an abundant energy source for humanity. However, there are some technical challenges that have to face in commercial-scale production of methane hydrate. The main problem is how to access the methane hydrates without destabilising the sea beds. Some depostits even are inaccessible. Besides, the production would be too expensive or require too much effort.  Another potential issue is environment issue. Although methane released from methane hydrates are cleaner than other fuel sources, it is still a hydrocarbon and combustion of methane will also released carbon dioxide gas. This will add to the accumulation of greenhouse gases in the atmosphere. 

Methane Hydrate looks like a piece of ice when take out from the sea floor.

Nowadays, India, Japan, Korea and other countries are presently engaged in the development of mining techniques to use methane hydrates as a source of energy in the future. There are still many unsolved question about the methane hydrates. Will it become the most harmful greenhouse gas in the future? Or will it the energy saviour that replace oil and coal to fuel our future? How long will the global warming go on before the methane hydrates get out? Nobody knows. These uncertainties highlight the need for further research. However, the answers are getting close.