(222ac) Vapor-Liquid-Liquid Equilibrium Measurements and Modeling of Ethanethiol + Methane + Water, 1-Propanethiol + Methane + Water and 1-Butanethiol + Methane + Water Ternary Systems At 303, 335 and 365 K and Pressure Up to 9 Mpa

New vapor-liquid-liquid equilibrium (VLLE) data for ethanethiol + methane + water, 1-propanethiol + methane + water and 1-butanethiol + methane + water ternary systems have been measured at three temperatures (303, 335, and 365 K) and pressures up to 9 MPa. A “static-analytic” method was used for performing the measurements; the total system pressure was maintained by CH₄. The objective of this work is to provide experimental VLLE data for mixtures of mercaptans (thiols) with other natural gas contents at its crude form for which no data are available in the open literature. Such data will help the industrial modeling of processes relevant to reduction of sulfur emissions. The Cubic-Plus-Association (CPA) equation of state was applied to describe the phase behavior of the investigated systems. It is shown that the CPA EoS satisfactorily describes the solubilities of  mercaptans (thiols) in all phases,. On the other hand, the modeloverpredicts the water content of the vapor phase, especially at low pressures and at the highest investigated temperature, i.e at 365 K. Furthermore no cross association was found to be significant in 1-propanethiol + methane + water and 1-butanethiol + methane + water ternary systems.