Phase behavior of system carbon dioxide + hydrogen sulfide

The global phase equilibrium behavior of the CO 2 +H 2 S system is discussed in this work for temperatures ranging from 160 K up to the critical region. Solid phases of CO 2 and H 2 S and corresponding equilibria have been modeled by considering either a 4 th -order equation of state (also used for the fluid phases) or a solid fugacity model for the pure components combined with an activity coefficient model (both coupled with a reference equation of state for the fluid phases). Phase equilibrium calculations have been performed by the minimization of the Gibbs Free Energy of mixing and compared to existing literature data. The types of pressure -mole fraction phase diagrams that can be encountered in the low -temperature thermodynamic region have been described. The temperature and pressure ranges where the phase behavior of the system changes have been identified and a representative phase diagram is presented for each range.