Predicting Surface Tension of n-alkanes Using The Gradient Theory and SRK EoS

In this study, surface tensions of several n-alkanes (n-C4 to n-C20) were predicted using the gradient theory coupled with SRK EOS. In the first attempt (case1), the influence parameter of the theory was estimated in terms of the SRK attractive and repulsive parameters. In the next attempt (case2) the influence parameter is regressed using the experimental data of surface tension. Finally, in case 3, the SRK EOS parameters were also regressed based on the experimental PVT data available in the literature. The average error in predicting surface tension decreases from 16% in case 1 to less than 2% in case 3.