Experimental measurement and thermodynamic modeling of methane hydrate dissociation conditions in the presence of aqueous solution of ionic liquid

• Dissociation conditions of methane hydrate in the presence of pure water and three ionic liquids are reported.
• A thermodynamic model is developed for prediction of the obtained data.
• Acceptable agreement is found between the obtained data and the predicted results.

In this communication, dissociation conditions of methane hydrate in the presence of pure water and aqueous solutions of three ionic liquids including 1-butyl-3-methylimidazolium tetrafluoroborate (0.10, 0.15 and 0.20 mass fraction), 1-butyl-3-methylimidazolium dicyanamide (0.10 mass fraction), and tetraethyl-ammonium chloride (0.10 mass fraction) were experimentally measured and are reported. The data were obtained in the 2.48–6.58 MPa pressure range and 272.1–282.0 K temperature range. A high-pressure equilibrium cell was used for performing the measurements pursuing the isochoric pressure search method. The hydrate dissociation conditions are modeled using the solid solution theory of van der Waals and Platteeuw for the hydrate phase along with the Peng–Robinson equation of state for the gas phase. For modeling of the aqueous phase, the NRTL model is applied. Acceptable agreement between the experimental data and the model results is observed.