Gas Hydrates

This review states contemporary views about gas hydrates, and also about non-stoichiometric clathrates with the general formula M·nH₂O. The known types of the hydrates and their crystal structure are described. The thermodynamics of hydrate formation is considered. Methods of determining the composition of the hydrates are described. Factual information concerning the hydrates of individual gases and organic liquids and mixed hydrates (binary and multicomponent) is given. The problem of the stabilisation of hydrates by an auxiliary gas is considered. Information is given about the density of hydrate crystals and the physical kinetics of the hydrate formation. Equations are given which are obtained by the methods of statistical mechanics and are based on the use of Lennard-Jones and Kihara potentials, and allow the main thermodynamic properties of the hydrates to be calculated. The problems of the industrial utilisation of the hydrates are examined (desalination of sea water, separation of liquid and gaseous mixtures, etc.). The theoretical principles of the inhibition of hydrate formation processes are stated. Bibliography of 180 references.