Phase equilibrium measurements and thermodynamic modeling of methane alcohol systems at ambient temperature

The (vapor + liquid) equilibrium data for binary systems of (methane + methanol), (methane + ethanol), and (methane + 1-propanol) at ambient temperature over a wide range of pressures, (1 to 8) MPa, were measured using a designed pressure–volume–temperature (PVT) apparatus. The phase composition and saturated density of liquid phase were measured for each pressure. The density of pure methanol, ethanol and 1-propanol was also measured at ambient temperature over a wide range of pressure (1 to 10) MPa. The experimental (vapor + liquid) equilibrium data were compared with the modeling results obtained using the Peng–Robinson and Soave–Redlich–Kwong equations of state. To improve the predictions, the binary interaction parameters were adjusted and the volume translation technique was applied. Both equations of state were found to be capable of describing the phase equilibria of these systems over the range of studied conditions. The Soave–Redlich–Kwong equation of state gave better predictions of saturated liquid densities than Peng–Robinson equation of state.