Methane hydrates are one of the many untapped energy sources within our earth. Methane hydrate is essentially water and methane put in a environment with low temperature and high pressure. It looks like ice, but if you were to take a match to it, it would light up. A combination of natural gas and water, normally known as clathrates, methane hydrate has the potential for a lot of energy.1 Energy that is available is double the amount of all the reserves of gas and oil, and this is solely in the permafrost hydrates. There are some hydrates that are on the bottom of the seafloor, which account for 95% of the total clathrates.2 It is not the best alternative energy source however, it still produces greenhouse gases. Methane is believed to have 10 to 20 times the short-term effects than carbon dioxide on the climate, but the long term effects are less than 50% as bad.2

The methane is trapped within the cage-like structures of water. This makes it extremely hard to extract the methane from the water, and there are no current methods of extracting it cheaply.1 When you combust methane, it produces carbon dioxide and water.

                      CH4 (g) + 2 O2 (g) -> CO2 (g) + 2 H2O (l)    ΔHfO = 890 kJ/mol

There are clearly vast amounts of energy that could be used, if an efficient method of extracting the methane gas from the methane hydrate was formed. Unfortunately, it is incredibly expensive at the moment. As well, as you can see from the equation, there is only 1 mole of carbon dioxide produced when one mole of methane is combusted. This is also a very good ratio of kJ/mol of carbon dioxide ratio, meaning it is cleaner than other forms of energy such as gasoline.

One cubic meter of the hydrate in gas form will produce 164 cubic meters of methane gas, when the gas inside is released. This is a substantial ratio for the amount of gas produced.

When methane hydrates are dissociated to create methane vapour, and you have either water or ice created, there is also a change in enthalpy. Methane hydrates create 55.3 kJ/mol, and this energy could be used as well.4

Methane hydrates, and clathrates in general seem to be a legitimate source of energy for the future. While there are still carbon emissions, the carbon emissions are not as bad as regular gasoline and oil. Methane will produce quite a substantial amount of energy when combusted, and thus makes methane hydrates a very reasonable solution to a coming energy crisis.

References

1. N/A, (June 2008). http://www.ornl.gov/info/reporter/no16/methane.htm. Retrieved November 10, 2008, from ORNL reporter Web site: http://www.ornl.gov/info/reporter/no16/methane.htm
2. Clymer, J. (2004, Dec. 24). Heat of Combustion & Respiratory Quotient Calculation. Retrieved November 10, 2008, from ORNL reporter Web site: http://home.fuse.net/clymer/rq/hoctable.html
3. N/A, (200, Aug. 29). Methane Hydrate – The Gas Resource of the Future. Retrieved November 10, 2008, from U.S. Department of Energy Web site: http://home.fuse.net/clymer/rq/hoctable.html
4.  Nakagawa, R (200, Aug. 29). Dissociation and specific heats of gas hydrates under submarine and sublacustrine environments. Retrieved November 13, 2008, Web site: https://circle.ubc.ca/bitstream/2429/2695/1/5353.pdf