Global phase behavior of mixtures of short and long <i>n</i>‐alkanes

Abstract

Abstract The perturbed‐hard‐chain model of Beret, Donohue, and Prausnitz, in the simplified version of Kim et al., is compared with recent VLE data on mixtures of ethane and n ‐alkanes with carbon numbers from 16 to 24. By using and extrapolating the linear relations between the three adjustable model parameters and the carbon number, as given by Kim et al., we find that the experimental isothermal bubble curves are well represented up to the critical pressure without the use of any adjustable parameters. Experimental Henry constants for ethane in eicosane are well predicted at all temperatures. We find this global model more accurate than the Soave‐Redlich‐Kwong equation, even if the latter is fitted isotherm‐by‐isotherm to individual mixtures with temperature‐dependent mixing parameters.