Thermodynamic and Kinetic Effects of Methanol in the Formation of Tetrahydrofuran Hydrate

The formation of hydrate for laboratory study requires difficult conditions such as high pressure (about 50 bar), for this purpose tetrahydrofuran (THF), which can easily form structure II hydrate under atmospheric pressure, is often used as a model for study of hydrate formation. In this study, the experiments were conducted in a batch reactor under atmospheric pressure at initial temperature of 2 °C. Methanol was added to the stoichiometric solution of water and THF at varying concentrations (0.5-2 wt¬%) as a hydrate inhibitor. The results indicate that methanol reduces the equilibrium temperature and acts as a thermodynamic inhibitor and also it can be used as a kinetics inhibitor by delaying nucleation and increasing the induction time. Therefore, the solution with concentration of 2 wt¬% methanol has the highest induction time and the lowest equilibrium temperature in the formation of THF hydrate.