Ajuste de parâmetros termodinâmicos experimentais de pressão e temperatura de equilíbrio da água e do etanol ao modelo de peng-robinson

Abstract

In general, the chemical industry uses the knowledge of the behavior of physicalchemical parameters, especially those of equilibria between phases (for example: liquid-vapor) to understand the processes applied in unit operations such as distillation. In these operations, water and ethanol are widely inserted. Either in their production or purification. In this perspective, the present work aims to adjust the parameters of the Peng-Robinson thermodynamic model to the experimental data of liquid-vapor equilibrium (VLE) obtained through the Othmer Ebulliometer in a system containing pure substances: water and ethanol. This was done by taking into account saturation pressure calculations and interactions performed by supplements of M. S. Excel (the libraries OCTOPUS and XSEOS) using the phi-phi approach. From the results obtained, the parameters fitted to the Peng-Robinson model showed inadequate behavior in predicting these vapor pressures, presenting as mean absolute deviation of the vapor pressure, 5.82% for water and 3.13% for ethanol. However, it was observed that the lower the pressure to which the system is subjected the greater the deviation from ideality. Thus, the adjustments may present greater consistency if used for conditions close to reality.