Generalized Correlation of Binary Interaction Parameters in Cubic Equations of State for Hydrocarbon/CO2, Hydrocarbon/H2S and CO2/H2S Systems

In the present work, we develop a predictive corresponding-states correlation for the binary interaction parameters of systems composed of hydrocarbons (HC), up to C10, with CO2 and H2S. Experimental data were collected from the literature for 12 HC/CO2 systems (1017 data points for 90 isotherms), 7 HC/H2S systems (293 data points for 27 isotherms), and the CO2/H2S systems (61 data points for 19 isotherms). Optimal kij were computed using the isofugacity method of Paunović et al. Computations were made for the van der Waals, Redlich-Kwong and Peng-Robinson equations of state, with the cohesion functions of Soave, Gibbons and Laughton, Stryjek and Vera, Twu et al., and our own group. Analysis of the results showed that kij are essentially the same for each binary pair and equation of state, regardless of the cohesion function used, thus making them true system properties. Average deviations obtained with the present correlation range from 2.5% to 4.5% for compositions, and from 1.5% to 4.0% for pressures, depending on the equation of state and type of binary pair. The correlation has also been used successfully in predicting vapor-liquid equilibria of ternary and higher mixtures involving these same components.