Experimental determination of densities and isobaric vapor-liquid equilibria of binary mixtures formed by a propyl alkanoate (methanoate to butanoate) plus an alkan-2-ol (C-3, C-4)

Vapor-liquid equilibria at 101.32 kPa of binary systems composed of the fir st four propyl esters, from methanoate to butanoate, and propan-2-ol or but an-2-ol and the vapor pressures of the pure, components were measured in th e same equilibrium still. The densities and excess volumes for the same mix tures were also determined at 298.15 K. The binary systems studied presente d a positive deviation from ideality, and four of the mixtures had azeotrop es at the working pressure, namely, propyl methanoate (1) + propan-2-ol (2) at x(1) = 0.570 and T = 349.4 K, propyl methanoate (1) + butan-2-ol (2) at x(1) = 0.933 and T = 353.6 K, propyl ethanoate (1) + propan-2-ol (2) a x(1) = 0.037 and T = 355.2 K, and propyl ethanoate (1) + butan-2-ol (2) at x(1) = 0.423 and T = 370.8 K. The isobaric VLE quantities were correlated toget her with the mixing enthalpies obtained for the corresponding mixtures usin g a suitable equation containing temperature-dependent parameters. The ASOG and UNIFAC group-contribution models were-used to predict the VLE values.