Generalized Temperature-Dependent Parameters of the Redlich-Kwong Equation of State for Vapor-Liquid Equilibrium Calculations

Abstract

The temperature-dependent parameters Qa and 6 of the Redlich-Kwong equation of state evaluated from vapor pressures and saturated liquid volumes for 13 pure components were correlated in terms of 7r. The coefficients of these correlations were further generalized in terms of . The generalized correlations have been successfully used to compute the 3 and Qb values for seven arbitrarily selected components other than those included in the generalization. The applicability of the values computed from the generalized equations was further demonstrated by evaluation of pure-component properties and by the calculation and prediction of vapor-liquid equilibria data for eight binary systems at 32 isothermal conditions.

Vapour‐liquid equilibria of hydrogen/coal liquid and methane/coal liquid systems at elevated temperatures and pressures

“…Still necessary are the densities of the pseudocomponents; these could be derived from earlier experimental determinations via the following correlation between density and mean boiling point (see Fig. 9): e = 0.4153 + 0.9097 x 10-3Tb (12) .…”

“…When investigating the temperature effect on the repulsion parameter, Lu et al [12] observed a minimum between 0.9 < TI < 1.0 and a maximum at the critical temperature. Accordingly, prediction of the saturated liquid volume by means of the RKS-EOS will be poor over a wide range of temperatures.…”

Comparison of Analytical Representations of Thermodynamic Properties of Methane, Ethane, and Ammonia

“…Many authors proposed cubic equations of state for the prediction of thermodynamic properties of pure compounds (and mixtures) with the assumption of temperature dependent parameters: Wilson (1964Wilson ( ,1966, Chueh and Prausnitz (1968), Chang and Lu (1970), Gray et al (1970), Joffe et al (1970), Vogh and Hall (1970a,b), Zudkevitch and Joffe (1970), Hsi and Lu (1971), Soave (1972), Chaudron et al (1973a,b), Lu (1973,1975), Lu et al (1974), Redlich (1975), Harmens (1975Harmens ( ,1977, Deiters and Schneider (1976), Fuller (1976), Hederer et al (1976), Huron (1976), Kato et al (1976), Robinson (1976a,b, 1977), Simonet and Behar (1976), Usdin and Mac Auliffe (1976), Chung and Lu (1977), Djordjevic et al (1977), Hamam et al (1977), Horvath and Lin (1977), and Medani and Hasan (1978). Fuller's (1976) modification of the Redlich-Kwong equation of state was selected for comparison because it is a cubic equation of state with three parameters and it gives promising results; it has the following form v~b FIMv + be)…”

A Modified Redlich-Kwong-Soave Equation of State Capable of Representing the Liquid State

“…In the development of Fuller's modification, saturated liquid volume and the condition of equal fugacity in the liquid and vapor phases were used in the procedure for determining the parameters. These properties are identical with those used in our development of the temperature-and substance-de- Recently, these two parameters were generalized in terms of the reduced temperature Tr and the acentric factor (Hamam et al, 1977). Using these generalized parameters, saturated liquid volumes and vapor pressures were calculated and compared with the literature data compiled by Canjar and Manning (1967) for 19 pure compounds together with those values obtained by the Fuller method in Table I.…”