Methane + neo-pentane system: VLE measurements, modeling of the phase diagram including solid phases

Abstract

New measurements of isothermal vapor–liquid equilibrium for the (CH4 + neoC5H12) system have been carried out using a static-analytic method for temperatures from 213 K up to 345 K and pressures up to 13 MPa. The method of Ungerer et al. has been used to extrapolate the VLE data to the critical-points region.Measured VLE data have been compared with literature values and used for investigating the low-temperature phase equilibrium behavior of the system (temperatures lower than the triple-point temperature of neo-pentane down to 213 K) where literature SVE data and thermodynamic models are in partial disagreement.Measured VLE data agree with literature VLE data and low-temperature VLE calculated from predictive models (PPR78 and PSRK EoSs). The new phase equilibrium measurements obtained at temperatures lower than the triple point temperature of neoC5H12 have allowed solving the discrepancy between literature data and model predictions and determining the global phase diagram of the system following the van Konynenburg and Scott’s and the Kohn and Luks’ classifications.