Prediction of the vapor–liquid phase equilibrium of hydrogen sulfide and the binary system water–hydrogen sulfide by molecular simulation

Abstract

NVT- and NpT-Gibbs ensemble Monte Carlo simulations were carried out in order to calculate the vapor–liquid phase equilibrium of hydrogen sulfide (between 203 and 363 K) and of the binary system hydrogen sulfide–water (between 313 and 433 K). Furthermore, the properties of supercritical hydrogen sulfide were determined at pressures between 0.1 and 100 MPa in the temperature range from 383 K to 423 K by NpT-Monte Carlo simulations. Molecular interactions were described using effective pair potential models together with common mixing rules, without any adjustable binary interaction parameters. Good agreement between simulation results and experimental data was found. Simulation of the binary system shows liquid-liquid equilibrium at temperatures below 393 K when pressures are above the vapor pressure of hydrogen sulfide.