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Vapor pressures of propyl acetate, 1-butanol and 2-butanol and the isobaric (vapor + liquid) equilibrium of n-propyl acetate with 1-butanol at 0.1, 0.15 and 0.6 MPa as well as n-propyl acetate with 2-butanol at 0.15 and 0.6 MPa was investigated using a dynamic stainless steel ebulliometer. The experimental data for the binary systems were tested and verified to be thermodynamically consistent by the point-to-point test of Van Ness. Different thermodynamic–mathematical equations together with several activity coefficient models were used to correlate the experimental data. The average absolute deviations for the vapor phase compositions are all below 0.01. In addition, the ASOG and three versions of UNIFAC group contribution models were used to estimate the (vapor + liquid) equilibrium data. The UNIFAC-Dortmund globally generated the best predictions. The mean error in the activity coefficient was less than 7%. For the n-propyl acetate (1) + 1-butanol (2) system an azeotrope has been verified at 0.15 MPa (x1azexp = y1azexp = 0.949 and Tazexp = 387.61 K) and at 0.6 MPa (x1azexp = y1azexp = 0.783 and Tazexp = 445.68 K) while for the n-propyl acetate (1) + 2-butanol (2) system, the azeotrope at 0.15 MPa was found at x1azexp = y1azexp = 0.331 and Tazexp = 383.03 K and was not detected at 0.6 MPa.

Isobaric vapor–liquid equilibria for the binary system methyl acetate + 2-butanol at 0.3 MPa and 0.6 MPa and ethyl acetate + 2-butanol at 0.3 MPa and 0.6 MPa have been determined. Thermodynamic consistency was checked. The Redlich–Kister and Herington area tests were employed. The Point test, Area test and Infinite dilution test (PAI) of Kojima et al. and the point-to-point test of Van Ness et al. were also applied. The different criteria for validation were considered, and all systems showed an acceptable quality. The results of global and individual deviations on experimental data calculated by using the Fredenslund et al. routine are shown. The different versions of the unique functional group activity coefficient (UNIFAC) and analytical solution of groups (ASOG) predictive group contribution models were applied. The experimental data were also correlated with the Peng–Robinson equation applying quadratic mixing rules.

Isobaric vapor–liquid equilibria for the binary system methyl acetate + 2-propanol at 0.3 and 0.6 MPa and ethyl acetate + 2-propanol at 0.3 and 0.6 MPa have been determined. Thermodynamic consistency was checked applying the Redlich-Kister and Herington area tests. In addition, the PAI test of Kojima et al. and the point-to-point test of Van Ness were applied. Validation criteria were considered for the different tests and all systems showed to be consistent. The global and individual deviations of experimental data were obtained from the Fredenslund routine. Azeotropes in these systems have been determined. It was verified that the singular points move towards lower ester mole fractions with pressure increase. The different versions of the UNIFAC and ASOG predictive group contribution models were applied.

Data from isobaric vapor–liquid equilibrium (VLE) for the binary systems methyl acetate, ethyl acetate, and n-propyl acetate with 1-propanol have been determined at 0.6 MPa employing a metal ebulliometer with recirculation of both phases. The thermodynamic consistency of experimental data has been verified with the Van Ness point-to-point test, using the routine in Fortran proposed by Fredenslund et al. The azeotropic point was observed for the binary systems ethyl acetate/1-propanol and propyl acetate/1-propanol. The activity coefficients of the liquid phase were calculated by considering the nonideality of the vapor phase. The binary systems studied show positive deviation from ideal behavior. Predictions obtained from the group contribution models ASOG and different versions of UNIFAC were verified by comparing the values provided by the models with experimental data of VLE.

Isobaric vapor–liquid equilibrium measurements are reported for the binary mixtures of Isobutyl Acetate with Ethanol, 1-Propanol and 2-Propanol at 0.6 MPa. The measurements have been performed using a dynamic still constructed in stainless steel. Both the liquid and vapor phases are recirculated. The data satisfy the thermodynamic consistency point-to-point test of Van Ness by using the procedures of both Hayden–O’Connell and Tsonopoulos. The activity coefficients have been calculated taking into consideration the non-ideality of the vapor phase. The activity coefficient values obtained by the UNIFAC and ASOG group contribution models are used to verify their predictive behavior.