Equations for Thermodynamic Properties

Cp = heat capacity of ideal gas Hzef, SZ0f = reference state for ideal gas Txef, PZ9f = reference temperature, reference pressure AHresid f resid residual enthalpy, residual entropy 

Peng-Roblnson Equation of State for Thermodynamic Properties 

Pief reference temperature, reference pressure 

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Benedict, Manson, Webb, George B., and Rubin, Louis C., An Empirical Equation for Thermodynamic Properties of Light Hydrocarbons and Then Mixtures, Chemical Engineering Progress, Vol. 47, No. 8, August, 195 I pp. 419-422. 

The graphs are based on the Peng-Robinson equation of state (1) as improved by Stryjek and Vera (2, 3). The equations for thermodynamic properties using the Peng-Robinson equation of state are given in the appendix for volume, compressibility factor, fugacity coefficient, residual enthalpy, and residual entropy. Critical constants and ideal gas heat capacities for use in the equations are from the data compilations of DIPPR (8) and Yaws (28, 29, 30). 

Benedict, M., Webb, G.B., and Rubin, L.C. (1940). An empirical equation for thermodynamic properties of light hydrocarbons and their mixtures I. Methane, ethane, propane and -butane. J. Chem. Phys., 8, 334—45. 

G. Equations for thermodynamic properties as functions of temperature References and notes for Chapter 4... 

In the first part of this paper general thermodynamic relations are presented for the calculation of thermodynamic properties from functions representing P-F-T and specific heat, velocity of sound, or Joule-Thomson data. In the latter part of the paper the equations for thermodynamic properties are developed in terms of zero-pressure (i.e., ideal gas) specific heats and are applied to a particular equation of state. 

A light-hydrocarbon mixture is to be separated by distillation, as shown in Figure 9.29, into ethane-rich and propane-rich fractions. Based on the specifications given and use of the Soave-Redlich-Kwong equation for thermodynamic properties, use ASPEN PLUS with the RADFRAC distillation model to simulate the column operation. Using the results of the simulation, with Tq = 80°F, a condenser refrigerant temperature of 0°F, and a reboiler steam temperature of 250°F, calculate the... 

Benedict,M.,G.B.Webb, andL.C.Rubin An Empiric al Equation for Thermodynamic Properties of Light Hydrocarbons and Their Mixtures II Mixtures of Methane, Ethane, Propane, and ra-Butane, J. Chem. Physics, vol. 10, p. 747,1942. 

M. Benedict, G. B. Webb and L. C. Rubin An empirical equation for thermodynamic properties... 

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