Vapor-liquid equilibrium of methane-n-pentane system at low temperatures and high pressures

Abstract

Measurements of the bubble-point compositions are reported and combined with dew-point data to give K-values for the methane--n-butane system at 40/sup 0/, 0/sup 0/, -20/sup 0/, -40/sup 0/, -60/sup 0/, -80/sup 0/, -100/sup 0/, -116.6/sup 0/, -120/sup 0/, -140/sup 0/, -160/sup 0/, -180/sup 0/, and -200/sup 0/F from the vapor pressure of n-butane up to critical point of the vapor pressure of methane. Experimental conditions were selected so that direct isobaric observations were also possible. Results showed significant deviations in the low-temperature range of the NGPSA critical loci as based on the experimental results of J. J. McKetta et al. from +40/sup 0/F to -140/sup 0/F. Data, however, are consistent in the high-temperature range as based on the data of B. H. Sage et al. from 70/sup 0/F to 250/sup 0/F. The 13 isotherms shown are constructed from data obtained from both experimental procedures.