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The article presents a study of the Lw-H-V equilibrium conditions, the dissociation enthalpy and the CO2hydration number of a clathrate hydrate formed from THF/CO2/water mixtures using a differential scanning calorimetry (DSC) method. New equilibrium values have also been obtained in the present study together with hydrate dissociation enthalpy. It also compares the new equilibrium measurements with modeling results based on a model combining Van der Waals and Platteeuw approach with a predictive equation of state.

The validity of differential scanning calorimetry (d.s.c.) as an alternate method of determination of thermodynamic conditions of stability of gas hydrates in aqueous media was asserted by comparison to literature data, in the case of methane hydrate in pure water and in sodium chloride solutions. Requirements for thermodynamic validity of the equilibrium temperatures measured by this technique were investigated and are discussed in details. New equilibrium data of (methane hydrate + water + methane) in aqueous calcium chloride solutions, in the concentration range from x=8.47·10−3 to x=53.27·10−3, were determined using the same method, in the pressure range 5 MPa to 11 MPa. Experimental results were compared to data computed using a model that is presented, showing very good agreement over a wide range of salt concentration. These results confirm the interesting perspectives of application of this technique in the field of gas hydrate thermodynamics. [Copyright &y& Elsevier]