HYDRATES OF ISO- AND NORMAL BUTANE AND THEIR MIXTURES

A wide variety of forcing conditions and nucleating agents has failed to produce any hydrate from normal butane under its own vapor pressure. The phase diagram for pure iso-butane hydrate has been determined. The critical decomposition conditions are 1.88°C and 1256 mm. Other properties found are the heat of formation, the depression of the formation temperatures by salt, and the hydrate composition. Mixtures of iso- and n-butane have been studied in the hydrate forming range and it is found that mixtures containing less than 71 wt.% iso- butane will not form hydrates under any conditions down to - 10°C. A theory for explaining the hydrate phase diagram with mixtures is derived, based on the work of Uchida and Hayano. © 1969.