Vapor-liquid equilibria of LNG and gas condensate mixtures by the Nasrifar-Moshfeghian equation of state

The Nasrifar-Moshfeghian (NM) equation of state (EOS) is used to predict vapor-liquid equilibria (VLE) of multi-component mixtures. The systems under study consist of liquefied natural gases (LNG), gas condensates, an asymmetric system, slightly polar systems and gas/water systems. van der Waals mixing rules are used and no pure component parameter is adjusted; however, the predictions compare well with experimental data, in particular, the solubility of CO₂, H₂S, CO and some hydrocarbon gases in water are calculated quite accurately. The average absolute error was found to be 7% for calculating gas solubility in water. For some systems, the volumetric properties were also predicted. The saturated liquid density of LNG systems is predicted with an average absolute error less than 0.6%.