Insights on the formation and dissociation mechanisms of cyclopentane hydrate obtained by using calorimetry and optical microscopy

International audienceIdentifying the characteristic properties of gas hydrates-including thermo-physical properties-is essential for determining their formation condition and in turn, controlling their yield/growth-rate for/in various applications/environments. Gathering these properties, during in-situ crystallization of gas hydrates, is rather challenging due to the harsh conditions they form and limited by the lack of coexistence of multiple characterization techniques. Owing to these limitations, crystallization process of some sII type gas hydrates and their characteristic properties are ill-defined. Therefore to unveil the complete picture of crystallization process of sII type gas hydrates, in this study, in-situ formation of a model system "cyclopentane hydrate" was monitored using a customized DSC sample holder with a transparent window on top. To this end, in-situ crystallization of cyclopentane hydrate was simultaneously followed by coupling optical microscopy along with scanning calorimetry. Further, we show that the cyclopentane hydrate formed by consuming a part of fresh water appearing after the fusion of ice instead of at a very low temperature ≤ −20 • C