Vapor pressures of pure compounds using the Peng-Robinson equation of state with three different attractive terms

Accurate representation of pure compounds vapor pressures is required to increase the robustness of equations of state when predicting phase equilibria for mixtures. Using cubic equations of state, this representation largely depends on improving the temperature-dependent attractive term of the equation of state (EOS) to cover data from the triple to critical points. With this purpose, the Peng-Robinson equation of state is applied with three different attractive terms: Mathias, Mathias-Copeman, and Carrier-Rogalski-Peneloux. Experimental vapor pressures for 311 pure compounds (9000 experimental values) have been fitted. The studied compounds include nitrogen compounds, oxides, sulfides, chlorides, oxyhalides, inorganic compounds, alkanes, cycloalkanes, alkenes, alkadienes, alkynes, aromatic hydrocarbons, halogenated alkanes, halogenated cycloalkanes, halogenated alkenes, halogenated aromatic hydrocarbons, alcohols, ethers, aldehydes, ketones, alkanoic acids, esters, phenols, heterocyclic oxygen compounds, heterocyclic nitrogen compounds, hydrocarbon nitrogen compounds, and sulfur compounds. Overall average absolute deviations of 0.416, 0.214 and 0.276% have been found for the resulting Peng-Robinson-Mathias (PRM), Peng-Robinson-Mathias-Copeman (PRMC), and Peng-Robinson-Carrier-Rogalski-Peneloux (PRCRP) equations of state, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.