Vapor–Liquid Equilibrium of Methane with Water and Methanol. Measurements and Modeling

There is a need for high-quality experimental phase equilibrium data in the petroleum and chemical industries, for example, mixtures of oil and gas with gas hydrate inhibitors (methanol, glycols) and organic acids. This includes a wide range of different systems, which all deal with processes that rely on phase equilibrium data for optimization. The objective of this work is to provide experimental data for hydrocarbon systems with polar chemicals such as alcohols, glycols, and water. New vapor–liquid equilibrium data are reported for methane + water, methane + methanol, and methane + methanol + water for several temperatures in the range 284 K to 324 K and in the pressure range (5 to 20) MPa.

The Cubic-Plus-Association (CPA) equation of state is used to model the phase equilibria data measured. A good agreement between predictions and experimental data is observed, supporting the reliability of the new data.