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

• VLE data for CO2 + H2S at 258–313 K.
• An equipment based on “static-analytic” method with phase sampling.
• Experimental data correlated with the Peng–Robinson (PR) and the Soave–Redlich–Kwong (SRK) EoSs.
• Models used to predict the critical locus.

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–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.