Research on Methane Hydrate Meta-stable Property of Gas Hydrates for Application to Natural Gas Storage and Transportation

Gas hydrates are group ice-like crystalline compounds, which form through a combination of water and suitably sized guest molecules under low temperature and high pressure conditions. The important properties of hydrate are very high gas to solid ratio, 1m(3) of hydrate may contain up to 175m(3) of gas (at standard condition). When the conditions change, the methane hydrate can dissociate to methane and water. Hydrate meta-stable (self-preservation) property has been reported by some researchers in recent years. If we can utilize the property economically in addition to its high-density gas containing property, it is possible to store and transport stranded natural gas at higher temperature and lower pressure compared to the conventional liquid natural gas method. The authors conducted laboratory experiments of methane hydrate dissociation in order to examine its potential for application to natural gas storage and transportation. As the result, relatively extremely slow dissociation was confirmed within temperature range between -7.5 degrees C and -3 degrees C. These results seem to be very promising for practical application of self preservation property to natural gas storage and transportation.