Critical properties prediction based on a quartic equation of state

Abstract

A quartic equation of state (EOS) [Yun et al., Fluid Phase Equilibr. 2001; 187-188: 275-298] is used for predicting critical properties of pure substances. Parameters in the EOS are rewritten as functions of temperature (T in K), and there are totally eleven substance-specific constants in the functions for each substance. Data of few experimental points including saturated vapour pressure, saturated liquid molar volume and evaporation enthalpy at some temperatures are required in this study to determine the substance-specific constants in the EOS, while the knowledge of molecular structure is not necessary. (2001)) est utilisée pour prédire les propriétés critiques des substances pures. Les paramètres de l'équation d'état sont réécrits comme des fonctions de la température (T, en K) et il y a un total de onze constantes propres aux substances dans les fonctions pour chaque substance. Les données de quelques points expérimentaux comprenant la pression de vapeur saturante, le volume molaire de la solution saturée et l'enthalpie d'évaporationà certaines températures sont requises dans cetteétude dans le but de déterminer les constantes propres aux substances dans l'équation d'état, alors que la connaissance de la structure moléculaire n'est pas nécessaire.

A New Quartic Equation of State Based on a General Form and Its Application to Pure Fluids

“…In order to implement the above optimization, the approach used by Zang et al is employed to determine the optimum set of values for the parameters S i and m i ( i = 1, 2, 3). Also, the following criterion should be satisfied along the vapor–liquid saturation curve: f l = f v …”

The New Method for Correlation and Prediction of Thermophysical Properties of Fluids. Critical Temperature

“…The equations acquired by this method are simple, understandable, and accurate. Cubic equation of state − is closely related to critical properties of pure substances, and thus it is also a way to obtain critical parameters. In addition, by employing molecular descriptors from computer simulation of molecular mechanics, Wakeham provided a new correlation for the estimation of critical parameters of hydrocarbons and achieved high precision.…”