ESTIMATION OF CRITICAL PROPERTIES OF BINARY-MIXTURES USING GROUP CONTRIBUTION METHODS

A new method for estimating critical temperature (7^), critical pressure (Pc), and critical volume (Vc) of both nonpolar and polar binary mixtures displaying continuous critical loci is proposed. The methodology is based on the group contribution concept for estimation of critical constants of pure compounds, and the combining rule concept for estimation of mixture properties. Lydersen group contribution method is used to demonstrate the application of this methodology. The combining rules are formulated and their adjustable parameters are determined using 43 nonpolar and polar binary mixtures including 417 data points for 7e>390 data points for Pc, and 219 data points for Vc, respectively. The method is then evaluated with 15 independently selected binary mixtures containing hydrocarbons, alcohols, ethers, amine, carbon dioxide, nitrous oxide, sulfur dioxide, chloroform, and hydrogen sulfide. The average deviations of the estimated Tct Pc, Vc are 1.60%, 7.26%, and 3.64%, respectively The present procedure does not require experimentally adjusted interaction parameters for estimation of the critical properties of a given binary mixture. © 1990, Taylor & Francis Group, LLC. All rights reserved.