Vapour-liquid equilibrium data for the hydrogen sulphide (H2S) + carbon dioxide (CO2) system at temperatures from 258 to 313 K

From the design of acid injection scheme to the impact of hydrogen sulphide in CCS scheme, knowledge of the phase behaviour of the hydrogen sulphide + carbon dioxide is essential. In this communication, new isothermal vapour-liquid equilibrium measurements for the binary system H2S - CO2 have been conducted at 258.41 K, 273.15 K, 293.47 K and 313.02 K in the pressure range from 1.0 to 5.5 MPa. The experimental method used in this work is of the static-analytic type, taking advantage of two magnetic capillary samplers (Rolsi™, Armines’ Patent) developed in the CTP laboratory. This experimental method allows the sampling in both liquid and vapour phases and their analysis by GC. The data were obtained with uncertainties within ±0.02 K, ±0.002 MPa, and 0.006 for molar compositions. It is demonstrated that both the Peng-Robinson (PR) equation of state (classical or the P-PR78 version) or the Soave - Redlich and Kwong (SRK) equation of state combined with the classical mixing rule and appropriate binary interaction parameters were able to satisfactorily describe the phase behaviour of the H2S-CO2 binary systems.