Calorimetric Characterization of Clathrate and Semiclathrate Hydrates

Differential scanning calorimetry (DSC) was used on model hydrates in order to assess the efficiency of kinetic inhibitors or to study the formation of hydrates in water-in-oil emulsions. The use of differential calorimetry with gas hydrates was initiated to study the thermodynamics of hydrates of methane and natural gas in deep offshore drilling fluids. At the same time, differential thermal analysis (DTA) was implemented for the study of carbon dioxide hydrates as phase change material for refrigeration applications. This chapter first presents the principles of the thermal analysis and calorimetry techniques that were used to study gas hydrates. It then focuses on the methodologies developed to form hydrates inside the calorimetric vessel and to precisely determine their dissociation temperatures and enthalpies as well as their heat capacities. Finally, the chapter gives an overview of the application of DSC to the study of hydrate formation kinetics in a dispersed aqueous phase.