Estimation of Water Content for Methane + Water and Methane + Ethane + n-Butane + Water Systems Using a New Sampling Device

Experimental data and thermodynamic modeling corresponding to water solubility in methane and in a synthetic gas mixture (94 mol % methane, 4 mol % ethane, and 2 mol % n -butane) are reported. Equilibrium data of water content in methane were measured in the (277.8 to 297.9) K temperature range and in the gas mixture in a larger (303.1 to 361.4) K temperature range for pressures up to 4.9 MPa, using a static-analytic apparatus that takes advantage of a new sampling device. The Valderrama modification of the Patel−Teja equation of state with the non-density-dependent mixing rules is used for modeling the fluid phases with previously reported binary interaction parameters. The hydrate phase is modeled by the van der Waals and Platteeuw solid solution theory using previously reported Kihara potential parameters. The new experimental data are in good agreement with the predictions of this model, with a previously developed semiempirical approach, and with some selected experimental data from the literature, demonstrating the reliability of the experimental data and technique and predictive methods used in this work.