Formulation of the Generalized Correlations for the Thermodynamic Properties at the Saturated State for Component Substances contained in the Natural Gases.

Abstract

As a first step to predict the thermophysical properties of natural gases, generalized correlations for the saturated properties such as the vapor pressure, the saturated liquid density, the saturated vapor density, and the heat of vaporization have been formulated on the basis of the three-parameter principle of corresponding states with acentric factor for 9 component substances contained in the natural gases, i. e., CH4, C2H6, C3H8, n-C4H10, i-C4H10, N2, CO2, H2S, and O2, and 3 simple fluids of Ar, Kr, and Xe. The present generalized correlation for the vapor pressure reproduces the experimental data within a deviation of ±1.0% in the reduced temperature range Tr>0.4. The present generalized correlation for the saturated liquid density reproduces the experimental data within a deviation of ±1.0% in the temperature range from the triple point to the critical point. The present generalized correlation for the saturated vapor density reproduces the experimental data within a deviation of ±2.0% in the reduced temperature range Tr>0.5. The reliability of the present generalized correlations for the vapor pressure and saturated liquid density was confirmed by the comparison with the experimental data for R22 and R114. The experimental data for the heat of vaporization are reproduced within a deviation of ±2.0% in the reduced temperature range Tr>0.5 by Clapeyron equation with the present generalized correlations for the vapor pressure, the saturated liquid density, and the saturated vapor density.