Seleção de modelos preditivos para cálculo de coeficientes de atividade à diluição infinita e sua aplicação a sistemas envolvendo hidrocarbonetos e solventes: acetonitrila e dimetilformamida.

Abstract

Several predictive models were used for the obtaining coefficients of activity the infinite dilution of binary systems formed by dimethylformamide (DMF) and acetonitrile with hydrocarbons. The predictive abilities of the models were investigated. contribution from ASOG groups and various versions of UNIFAC, for predicting activity coefficients of the above systems cited. We also studied the original MOSCED models and modified by Wen-Teh Chen as well as introduced small modifications in order to improve the quality of the predictions. Notably, we have tried to improve the adjustment of (x, a and P), with the temperature as well as the asymmetry parameters in order to decrease the under prediction of the coefficients of activity at infinite dilution, observed with the original versions. The y ° s obtained with the various predictive models studied, were used to obtain binary interaction models of Van Laar (26), Margules (27), Wilson (1), NRTL (2) and UNIQUAC (3). These parameters were tested in the liquid-vapor equilibrium calculation of systems formed by DMF and acetonitrile with hydrocarbons. The results obtained were extremely satisfactory, proving the extreme utility of predictive models of coefficients of liquid phase activity and utilization of these coefficients to obtain binary parameters.