Heterogeneous phase equilibria of the methane—hydrogen sulfide system

The experimental apparatus and procedures which were developed for the determination of the heterogeneous phase behavior of the methane‐hydrogen sulfide system have been described in a previous paper (2). The apparatus and procedures were tested and employed at temperatures in the range of —300 to 300°F. and at pressures up to 2000 1b./sq. in. abs. The vapor‐liquid, vapor‐solid, liquid‐vapor‐solid, liquid‐liquid‐vapor and liquid‐liquid‐solid phase border curves were determined for six mixtures of methane and hydrogen sulfide. The phase compositions were determined at selected points along the three‐phase univariant equilibrium lines. An invariant point (quadruple point) was found which involves the equilibrium of two liquid phases, a vapor phase, and a solid phase. These data are presented on P‐T and T‐X diagrams. The data contribute to the understanding of phase behavior of light hydrocarbons containing hydrogen sulfide.