Isobaric vapor-liquid equilibria for two binary systems (2-methyl-1-pentanol + 2,3-butanediol and 3-methyl-1-butanol + 2,3-butanediol) at (40, 60, 80, and 101) kPa

Abstract Isobaric vapor-liquid equilibrium data were measured for the two binary systems of 2-methyl-1-pentanol + 2,3-butanediol and 3-methyl-1-butanol + 2,3-butanediol using a modified Othmer still VLE apparatus at 40, 60, 80 and 101 kPa. The standard uncertainty of the pressure and temperature was 0.13 kPa and 0.1 K, respectively. To assess the thermodynamic consistency of the experimental data, Herington area test method and Van Ness-Byer-Gibbs test method have been used. The experimental data were also correlated with the two activity coefficient models, NRTL and UNIQUAC, and the binary parameters for the models have been calculated. For the quantitative analysis of the experimental data, we used the root-mean-square deviation (RMSD) and the average absolute deviation of the temperature (AAD-T) and the vapor-phase composition (AAD-y). Overall AAD-y were 4 × 10−4 (NRTL) and 5 × 10−4 (UNIQUAC) for 2-methyl-1-pentanol + 2,3-butanediol system, and 5 × 10−4 (NRTL) and 6 × 10−4 (UNIQUAC) for 3-methyl-1-butanol + 2,3-butanediol system, respectively. This test results support the validity of the models used for the two binary systems studied in this work.