Clathrate Hydrates. Группа авторов

hydrates with temperature and was the first to use the equation to determine gas hydrate compositions. 1885 Chancel and Parmentier reported a simple hydrate of chloroform. This was one of the first so‐called “liquid hydrates” whose guest components are liquids at ambient temperature. 1887–1888 Bakhuis Roozeboom applied the Gibbs phase rule to heterogeneous equilibria and systematically classified chemical and physical processes according to number and nature of the components and phases present. He published on the treatment of the invariant points at which equilibrium lines meet. 1888 Villard prepared hydrates of CH₄, C₂H₆, C₂H₄, N₂O, and propane (1890). 1890 Villard recognized the stabilizing effect of air on the decomposition of gas hydrates. In the search for other “help‐gases” he identified both hydrogen at 23 atm and oxygen at 2.5 atm as increasing the decomposition temperature of ethyl chloride. 1897 On the basis of careful measurements on the large number of hydrates then available, Villard presented a definition of the composition of gas hydrates (Villard's law). 1897 de Forcrand and Thomas discovered new help‐gases (CO₂, C₂H₄, C₂H₂, and SO₂). 1902 de Forcrand used calorimetric data and a generalization of Trouton's rule to calculate hydrate compositions for 15 hydrates. About half had compositions in agreement with Villard's law. 1923 Bouzat produced summary statements giving the then current definition of hydrates, their structure, and composition. 1926 Schroeder wrote an influential monograph summarizing the state of knowledge of gas hydrate to that date. 1934 Hammerschmidt, after reading Schroeder's book, showed that gas hydrates are more likely to form plugs in natural gas pipelines than ice. 1936–1937 Nikitin prepared mixed hydrates of noble gases and SO₂ and showed that the noble gases could be separated by partitioning between the solid hydrate and the gas. His observations were first consistent with the “solid solution” nature of hydrates. 1946 Deaton and Frost presented experimental data on hydrate phase equilibria of natural gas components and methods of hydrate prevention. 1946 Miller and Strong proposed natural gas storage in hydrate form. 1947 Powell coined the term “clathrate” for materials having a guest molecule residing in a cavity formed in a host lattice. 1949 von Stackelberg used X‐ray diffraction data to propose a structure for a gas hydrate of chloroform and H₂S. Although the structure, based on a lattice with holes for guests, was incorrect, it was a radical departure from the molecular structure current up until that time. von Stackelberg had studied the X‐ray diffraction of gas hydrates prior to this time, but his original photographic plates had been destroyed in aerial bombardment during World War II. 1951 Clausen introduced the pentagonal dodecahedron as a structural component of gas hydrates, and von Stackelberg and Muller's X‐ray diffraction data confirmed the crystal structure of the “structure II” (sII or CS‐II) hydrate proposed by Clausen. 1952 Clausen, von Stackelberg, and Pauling and Marsh provided a structure for “structure I” (sI or CS‐I) gas hydrates. 1952 Delsemme and Swings suggested the presence of gas hydrates in comets and interstellar grains. Delsemme later suggested that the outgassing of comets on approaching the sun could be due to decomposition of hydrates. 1957–1967 Barrer and coworkers studied hydrate thermodynamics, kinetics, and separation of gas mixtures with hydrate formation. 1959–1970 Jeffrey and coworkers used single‐crystal X‐ray diffraction to obtain structural data for clathrate hydrates, semi‐clathrates, and salt hydrates. 1959 van der Waals and Platteeuw presented the “solid solution” statistical thermodynamics model for clathrate hydrates. 1961 Miller and Pauling hypothesized hydrate formation as a mechanism for anesthesia arising from inert noble gases, in particular xenon. 1961 Miller suggested the presence of gas hydrates in the planets, planetary rings, and interstellar space in the solar system. 1963 Davidson used dielectric methods to study clathrate hydrates. He discovered new water‐soluble (polar) guests for clathrate hydrates, measured the dynamics of guest and host molecules, found that water molecule reorientation rates depend on the nature of the guest molecule, and postulated the presence of guest–host hydrogen bonding capable of generating Bjerrum defects. 1965 Makogon reported on natural gas hydrates found in the Siberian permafrost. 1965 Kobayashi and coworkers applied the Kihara intermolecular potential to van der Waals–Platteeuw theory to represent the guest–cage interactions. 1965 Davidson and coworkers started nuclear magnetic resonance (NMR) measurements on clathrate hydrates and demonstrated that the SF₆ guest in sII clathrate rotates isotropically even at 77 K. 1966 Glew and Rath showed that the equilibrium compositions of Cl₂ and EO clathrate hydrates are variable, in accordance with van der Waals–Platteeuw theory. 1968 Glew and Haggett studied EO hydrate growth kinetics and showed that the process is governed by heat transfer over a wide range of concentrations. 1969 Miller predicted air hydrates should be present in glacier ice, CO₂ hydrates on Mars, and CH₄ hydrates on the outer planets and moons. 1969 Ginsburg studied natural gas hydrates in geological settings. 1971 Stoll, Ewing, and Bryan found that anomalous wave velocities (bottom‐simulating reflectors) are associated with marine offshore natural gas hydrate deposits. 1972 Parrish and Prausnitz developed convenient computer code for applying the van der Waals–Platteeuw theory to the calculation of gas hydrate phase diagrams. 1972 Tester, Bivins, and Herrick