NEW THERMODYNAMIC CONSISTENCY TEST FOR ISOBARIC VAPOR-LIQUID-EQUILIBRIUM DATA

A thermodynamic consistency test for the vapour-liquid equilibrium dat a obtained under isobaric conditions is proposed. According to this pr ocedure, the coexistence equation with correction term for the nonidea lity of the vapour phase was used. The differential equation has two s ingulier points and was solved by numerical integration according to t he method predictor-corrector Adams combined with the classical Runge- Kutta method. The nonideality of the vapour phase is considered by usi ng the second coefficients from the virial equation of state. The resi duals of the vapour phase obtained as differences between the calculat ed, respectively experimental values were statistically analysed to de tect systematic and random errors. In this order Student and Abbe test s were used. A study of the influence of the method and the step of th e integration is also presented. In this order Runge-Kutta and Adams m ethods were compared and for the estimation of the second virial coeff icients different published procedures have been taken into account. I n this paper the method of Tsonopoulos and Hayden - O'Connell are take n into account. A correlation analysis is performed to evaluate the re sults of this study.