Isobaric Vapor–Liquid Equilibrium for Nine Binary Systems of Cracking C5 Fraction at 250 kPa

The isobaric vapor–liquid equilibrium (VLE) data for nine binary systems of cracking C5 fraction including n-pentane + cyclopentane, n-pentane + cyclopentene, isopentane + 2-methyl-2-butene, isopentane + cyclopentene, cyclopentane + 2-methyl-2-butene, cyclopentane + cyclopentene, cyclopentane + isoprene, isoprene + 2-methyl-2-butene, isoprene + cyclopentene at 250 kPa have been measured using a VLE recirculating still. All of the experimental data were checked with the Herington thermodynamic consistency test, which showed thermodynamic consistency. The experimental VLE data were correlated with the Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models. The results show that the calculated values of the vapor-phase mole fraction and boiling temperature by the Wilson, NRTL, and UNIQUAC models agree well with the experimental data. The ideal liquid model was also used to compare with experimental data, which showed a few small differences which indicated the small deviations of these systems from the ideal liquid. The universal quasichemical functional group activity coefficients (UNIFAC) model was also used to predict the VLE data for these systems, which agree well with the experimental data, except cyclopentane + isoprene system which shows a little bigger deviation.