Improvements of the Patel-Teja equation of state

Abstract

The Patel-Teja equation of state has been improved by modifying the temperature dependence of the attractive term to give simultaneous representation of vapor pressure, liquid density, and liquid heat capacity data for polar and nonpolar compounds. For many high-boiling industrially important compounds, the combination of available heat capacity and vapor pressure data provides a thermodynamically sound method of establishing the temperature dependence of the attractive term in the most practical range of 273-523 K. The performance of the equation of state is greatly improved if the critical pressure is used as the adjustable parameter to correlate the thermodynamic properties under the conditions of interest.

Measurements of HmE and VmE for (propane + sulphurhexafluoride) in the near critical region

“…Patel (15) has recently suggested an improved expression for the temperature dependence of the α(T ) function of the equation. This more complex form gives a better fit to vapour pressures, liquid densities and liquid heat capacities of both polar and non-polar compounds, and in a future publication comparison with our data will be made.…”

Excess molar enthalpies of (carbon dioxide + ethene) in the liquid and near-critical regions

“…The fit to residual volumes or enthalpies is not perfect, and one would not expect it to fit values of excess volumes or excess enthalpies over anything but a small range of temperatures or pressures. Patel (18) has recently suggested an improved expression for the temperature dependence of the α function of the equation. This more complex form gives a better fit to vapour pressures, liquid densities and liquid heat capacities of both polar and nonpolar compounds, and in a future publication, when excess volumes for (carbon dioxide + ethene) are reported, comparison with our data will be made.…”

Near critical measurements of HmEandVmE for { xCO2+ (1 −x)SF6} and measurements made over the pressure range 2.5 to 10.0 MPa at the temperature T= 301.95 K

“…Patel (11) has recently suggested an improved expression for the temperature dependence of the α(T ) function of equation (2). This more complex form gives a better fit to vapour pressures, liquid densities, and liquid heat capacities of both polar and non-polar compounds, and in a later publication, comparison with our results will be made.…”

“…Whereas the pure-component residual enthalpies and H E m are all zero in the limit of p → 0, the pure component residual volumes become the second virial coefficients B 11 and B 22 , and V E m becomes equal to the excess second virial coefficient of the mixture.…”