Nonanalytic Equation Of State Research Articles

Toluene Thermophysical Properties from 178 to 800 K at Pressures to 1000 Bar

The thermodynamic data for toluene have been evaluated and fit to a highly constrained, nonanalytic equation of state. Comparisons of the equation with the selected PVT and derived property data are given. Extensive tables are presented providing tabular values for coexisting liquid and vapor as well as for the single phase along isobars. The equation of state and tables cover the range from the triple point (178.15 K) to 800 K, with pressures to 1000 bar.

Benzene Thermophysical Properties from 279 to 900 K at Pressures to 1000 Bar

The thermodynamic data for benzene have been evaluated and fit to a highly constrained, nonanalytic equation of state. Comparisons of the equation with the selected PVT and derived property data are given. Extensive tables are presented providing tabular values for coexisting liquid and vapor as well as for the single phase along isobars. The equation of state and tables cover the range from the triple point (278.68 K) to 900 K, with pressures to 1000 bar.

A method for improving equations of state near the critical point

Accurate nonanalytic equations of state have been developed for pentane and carbon dioxide for use as reference equations in the critical region. This was done using a method originated by Fox which transforms any analytic equation of state into a nonanalytic equation of state. For this study, a 32 constant analytic BWR equation of state developed by Jacobson and Stewart was transformed into a nonanalytic equation of state. The nonanalytic equation of state is more accurate in the critical region for the prediction of the PVT properties of carbon dioxide than is a Schmidt-Wagner analytic equation of state developed at the National Bureau of Standards. The nonanalytic equation of state is slightly less accurate over the whole PVT surface than the Schmidt-Wagner equation of state, but the predicted nonanalytic surface makes a smooth transition into the classical region. This is an improvement over the scaled fundamental equation of state which breaks down at a small distance away from the critical point.

Densities of Compressed Liquid Methane, and the Equation of State.

Experimental PVT data for liquid methane are reported at densities from 1.8 times critical up to the freezing liquid, at temperatures from 91 to 245 K and pressures to 350 bar. A nonanalytic equation of state is adjusted to these and other PVT data from ideal gas states to the freezing liquid, at temperatures from the triple point to 400 K.