Methane hydrates are a type of ice that contains methane molecules in a cage-like structure. The methane is trapped in the hydrate by water molecules, which form a lattice around it. Methane hydrates are found in marine sediments and permafrost. They are also known as clathrates or gas hydrates.
Methane hydrates are an important source of natural gas. They have the potential to be a major energy resource, but they are also a hazard because they can cause offshore drilling rigs to collapse.
Methane hydrates were first discovered in the early 19th century. In 1810, Sir Humphry Davy found that when methane was dissolved in water, it formed a white substance that looked like ice. He did not know what this substance was, but he called it “methylic acid”.
In 1834, Friedrich Wöhler synthesized urea from ammonium cyanate, proving that organic compounds could be made from inorganic compounds. This discovery led to the realization that Davy’s methylic acid was actually methane hydrate.
In the late 19th century, scientists began studying methane hydrates more systematically. They found that methane hydrates occur naturally in sediments and permafrost. In 1929, Vladimir Ioffe and Sergei Vasilievskii calculated the thermodynamic properties of methane hydrate and showed that it is stable at low temperatures and high pressures (Ioffe and Vasilievskii 1929).
Methane hydrates were first exploited commercially in Japan in 1963 (Yamamoto et al 1963). Since then, there have been several other attempts to produce natural gas from methane hydrate deposits, but these have all been unsuccessful so far (Sloan 1998).