Gas Hydrate - Investigations of Their Various Properties

ABSTARCT: As a result of geophysical researches in non-conventional energy sources in the earth in recent years, the discovery of large gas hydrate accumulations in terrestrial permafrost regions of the Arctic and beneath the sea along the outer continental margins of the world's oceans creates the interest of gas hydrates as a possible energy resource. Gas-hydrates are crystalline form in which gases (mainly methane) are observed to be trapped within a framework of hydrogen bonded water molecules (Kvenvolden, 1998). They form at elevated pressure and moderately cooled temperature, and occur worldwide in two distinct regions of permafrost and outer continental margins (Sloan, 1990). According to the U.S. Geological Survey, the worldwide amount of carbon bound in gas hydrates is conservatively estimated to total twice the amount of carbon to be found in all known fossil fuels on Earth. Gas hydrates, also known as clathrates, are frozen, crystalline solids comprising gas molecules contained within a lattice of water molecules. The most common form of gas hydrate is methane hydrate, but other gas molecules include ethane, propane, butane, iso-butane, pentane, nitrogen, carbon dioxide and hydrogen sulphide. Natural gas hydrates are being studied worldwide as transport manufactured materials as they are more suitable for large-scale transport of natural gas over long distances than liquefied natural gas. A main component of hydrate deposits is methane hydrate formed from water and methane molecules so the hydrocarbon gas mixture contains >99% methane. The main aim of this paper is to investigate the various thermal and physical properties of gas hydrates that are the outcome of the experiments performed.