Comparative Study between Cubic and non-Cubic Equations of State Using Carnahan-Starling Repulsive Term: Application of Temperature-Dependent Alpha and Beta Functions

Abstract

Studies on phase equilibria data behavior of pure substances are motivation to the researchers due to importance of these data for the scientific and industrial applications. Several EOS were proposed and its modifications have been made, whose aim is to improve the correlation between experimental and calculated thermophysical properties. This work proposes a comparative study between the PVT calculated data using cubic and non-cubic equations of state, in which its original repulsive term is substituted by the Carnahan-Starling hard-sphere repulsive term; furthermore, generalized expression to calculate (Tr,) and (Tr,) functions are used. Experimental data of vapor pressure for various pure compounds were compared to the calculated vapor pressure data showing satisfactory agreement, when this proposed modification is employed.

Thermal and Chemical Aspect in Equation of State and Relation with Generalized Thermodynamic Entropy

“…Outcomes of the present research can be regarded as a theoretical paradigm highlighting an extended perspective on studies already published [18,19] on the state equation of real systems and their properties along irreversible processes among non-equilibrium states.…”

“…As regard the differential form of mechanical entropy M S , appearing as a contribution in Gibbs equation: (19) the following expression has been proposed [11,12]:…”