Application of the simplified-perturbed-hard-chain theory for pure components near the critical point

Abstract

Abstract van Pelt, A., Peters, C. and de Swaan Arons, J. 1992. Application of the Simplified-Perturbed-Hard-Chain Theory for pure components near the critical point. Fluid Phase Equilibria, 74: 67-83. This investigation is part of a study to classify the fluid phase behaviour of binary mixtures, using the Simplified-Perturbed-Hard-Chain Theory (SPHCT). The SPHCT equation of state has been evaluated with new parameter values for c, V★ and T★. They allow the saturated vapour pressures of non-polar substances to be predicted near their critical point. A procedure is presented that allows the fitting of saturated vapour pressure data while fixing pc and Tc at the experimental values. Moreover, a very simple relation is proposed to obtain values of the parameters ϵ k and σ for the normal alkanes. These parameters are necessary for mixture calculations. The maximum deviation in the saturated vapour pressure curve is less than 5%, and the maximum average absolute deviation is about 3% within a temperature range of 0.75