The Effect of Sodium and Chloride Salts on Tetrahydrofuran Hydrate Formation by Using a Differential Scanning Calorimetry

Abstract

In this study, a differential scanning calorimetry (DSC) has been used to characterize tetrahydrofuran (THF) hydrate formation with and without the presence of sodium and chloride salts. The thermal properties including the heat of formation, phase change temperature and specific heat capacity of THF hydrate formation have been determined. When salts are present, THF hydrate is inhibited, so that the phase change temperature shifts to a lower temperature, a broadening of the DSC peak can be seen and the height of the peak and the heat of formation decreases. Because the heat capacity depends on the heat of formation, it reduces when salt is present. The results show that the sodium salt solutions have exhibited the best performance on delaying nucleation of hydrate in order of Na₂SO₃> NaF > NaCl, while chloride salt solutions, especially CaCl₂, have demonstrated that can reduce the heat of formation to around 65% compared to that of without salt.