A SIMPLE EQUATION OF STATE FOR NONPOLAR GASES

Gas p-v-T data are predicted up to critical densities and beyond, and up to three times the critical temperature, on the basis of second virial coefficients and critical densities. The tool is an augmented hard convex body equation (Haar-Shenker-Kohler or HSK equation), which uses the second and third virial coefficient and sets the fourth and fifth virial coefficient equal to zero. For the third virial coefficient, an earlier correlation is used which gives the third in terms of the second virial coefficient. The hard body volume can be calculated from the critical volume. Examples given comprise methane, ethane, oxygen, nitrogen and some mixtures.