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Vapor-liquid equilibria for difluoromethane (R32) + and pentafluoroethane (R125) + 1,1,1,3,3,3-hexafluoropropane (R236fa) at 303.2 and 323.3 K

Journal Article · · Journal of Chemical and Engineering Data
DOI:https://doi.org/10.1021/je980195e· OSTI ID:346956
;  [1];  [2]
  1. National Research Council, Padova (Italy). Inst. of Refrigeration
  2. Polish Academy of Sciences, Warsaw (Poland). Inst. of Physical Chemistry

Isothermal vapor-liquid equilibria (VLE) for the binary systems difluoromethane (R32) + 1,1,1,3,3,3-hexafluoropropane (R236fa) and pentafluoroethane (R125) + 1,1,1,3,3,3-hexafluoropropane (R236f) were measured at 303.2 and 323.3 K using a recirculation apparatus in which the vapor phase was forced through the liquid. The phase composition at equilibrium was measured by gas chromatography, calibrating its response using gravimetrically prepared mixtures. Both systems show a slight deviation from Raoult`s law. The data were reduced by the Carnahan-Starling-De Santis EOS. The deviations observed in vapor composition, averaging below 0.003 in mole fraction, confirm the consistency of the experimental findings and the model used for their reduction. Calculated excess Gibbs energy functions reveal values to be within {+-}40 J/mol at T = 303 K. The margins of error in pressure, temperature, and composition of vapor and liquid-phase measurements were estimated to be less than {+-}0.15%, {+-}0.005 K, and {+-}0.0015 of mole fraction, respectively.

OSTI ID:
346956
Journal Information:
Journal of Chemical and Engineering Data, Journal Name: Journal of Chemical and Engineering Data Journal Issue: 2 Vol. 44; ISSN JCEAAX; ISSN 0021-9568
Country of Publication:
United States
Language:
English