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

Abstract Identifying 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 co-existence 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.