Experimental Measurement and Modeling of the Solubility of Methane in Methanol and Ethanol

Knowledge of hydrate inhibitor distribution is essential for the economic operation of gas transportation and processing. A number of measurements were made to determine the solubility of methane, the main constituent in natural gas, in methanol and ethanol. Methanol and ethanol are two of the most commonly used gas hydrate inhibitors in the petroleum industry. The solubility data are essential in developing binary interaction parameters used in predicting inhibitor distribution in multicomponent systems. The solubility of methane in methanol at 273.15 K and 1.1–47 MPa and methane in ethanol at five different isotherms between 238.15 and 298.15 K and 0.3–41.7 MPa was measured. The results showed an average repeatability of 2.5% between the measured points. The results from the ethanol solubility measurements were used to optimize the interaction parameters of the CPA-SRK72 equation of state. The experimental data generated in this work are compared to literature data and to the calculations through the thermodynamic model tuned on our experimental data. The model calculations using a single binary interaction parameter was able to reproduce the new experimental with an absolute average deviation of 5.3% over the full data range, demonstrating the reliability of the approach.