A STUDY OF PHASE EQUILIBRIUM OF H2S IN SEVERAL PHYSICAL SOLVENTS USING CHEMCAD SIMULATOR

Abstract

CHEMCAD process simulator was used for the analysis of the literature experimental phase equilibrium data of H2S with three physical solvents (Sulfolane, Propylene Carbonate (PC), and N-Methyl-2-Pyrrolidone (NMP)) at different temperatures ( 298.15 oK , 323.15 oK, and 373.15 oK). Two thermodynamic models, Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK), were used.
The equilibrium data of H2S- Sulfolane and H2S- Propylene Carbonate (PC) systems were successfully correlated using SRK thermodynamic model. The deviation was noticed only for H2S-Sulfolane system as the temperature increases to 373 oK, to give a deviation of less than 5% .
The thermodynamic models used in present study, PR, and SRK , built in CHEMCAD simulator and used as such without modification, fail to correlate the equilibrium data of H2S- NMP (N-Methyl-2-Pyrrolidone) system for all temperature range used.
Modifications of the thermodynamic models were performed by editing user defined binary interaction parameters (BIP) of the systems used, gives good results.

KEYWORDS
Vapor–Liquid Equilibria, H2S, Physical Solvents, CHEMCAD Simulator, Thermodynamic Models, Equation of state and correlation