Phase equilibria of clathrate hydrates in CO2/CH4 + (1-propanol/2-propanol) + water systems: Experimental measurements and thermodynamic modeling

Hydrate equilibrium/dissociation conditions of methane/carbon dioxide in the presence of aqueous solutions of 1-propanol/2-propanol have been studied in this communication. The hydrate dissociation conditions of water + CO2 and water + CO2 + 2-propanol systems have been measured in concentration range of 0, 0.02, 0.05, 0.10, 0.15 and 0.25 mass fractions in 274.5-283.1 K and 1.93-4.54 MPa, temperature and pressure ranges using an isochoric pressure-search method. A thermodynamic model has been developed to estimate the hydrate dissociation conditions for the systems of water + CH4/CO2 + 1-propanol/2-propanol based on combinations of van der Waals and Platteeuw model, Peng-Robinson equation of state (PR EOS), and NRTL and Wilson activity coefficient models. The parameters of Langmuir constants have been obtained by fitting experimental data while structural, and interaction parameters of activity coefficient models have been taken from literature. Based on our experimental data, 2-propanol likely acts as thermodynamic inhibitor for CO2 hydrate. The results of the model are in satisfactory agreement with the experimental data.