Prediction of thermodynamic properties for low temperature hydrocarbon process calculations

Abstract

Analytical expressions for calculating vapor-liquid compositions, enthalpies, and entropies have been developed for hydrocarbon mixtures containing none or some of the nonhydrocarbon gases and evaluated against experimental measurements of vapor-liquid equilibria and enthalpies. The evaluation results show that the proposed equations can be applied over wide range of conditions with good accuracy. These equations are extensions and improvements of equations presented previously by Lee and Edmister (1971~) mainly for low temperature thermodynamic property calculations.

Vaporization Enthalpy of Pure Refrigerants: Comparative Study of Eighteen Correlations

“…To apply this equation, DIPPR used the values of the derivatives of vapor pressure with respect to temperature obtained from the vapor pressure correlation in a differentiated form; liquid volumes were calculated from the liquid density correlation; and the vapor volume was calculated by the Lee-Erbar-Edmister equation. 44 When the Clapeyron estimation resulted in a poor curve or disagreed with experimental data, prediction by the Lee-Kesler method 45 was used. As a last resort, the Watson method 25 was used if there is at least one point of reliable vaporization enthalpy datum.…”

Prediction of Vapor-Liquid Equilibria of Undefined Mixtures

“…Computer methods for making vapor-liquid equilibria calculations on petroleum fractions were developed by Chao and Seader (1961), Grayson and Streed (1963), Hoffman (1968), Soave (1972), Starling and Han (1972), Lee et al (1973), and Peng and Robinson (1976). All of the methods, with the exception of Hoffman's, begin by assuming an initial set of K values and performing a flash calculation to find x¡, y¡, and V, based on the material Using the calculated values of x¡, y¡, and V, the various equations of state (Soave, Peng-Robinson, and Starling-Han) can be solved for the fugacity of the liquid (/jL) and vapor (fiV) phases.…”

Comparison of generalized equations of state to predict gas‐phase heat capacity

“…Each of the 345 groups of calculated C, departure is compared with its corresponding base C, departure group. The group standard fractional deviation, up, is calculated using the following equation: Lee-Kesler (1975) 3-parameter corresponding states correlation 2 Lee-Erbar-Edmister (1973) eq. of state 3 Sugie-Lu (1970, 1971) eq.…”