A cubic equation of state with group contributions for the calculation of vapor-liquid equilibria of mixtures of hydrofluorocarbons and lubricant oils

Journal Article · Sat May 01 04:00:00 EDT 1999 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie980570w· OSTI ID:352675

Elvassore, N; Bertucco, A ^[1]; Wahlstroem, A ^[2]

---

1. Univ. di Padova (Italy). Ist. di Impianti Chimici
2. Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Heat and Power Technology

A method for calculating the vapor-liquid equilibria of mixtures between hydrofluorocarbons and lubricant oils is presented. A cubic equation of state is used containing three parameters: the attractive on, a, the volume parameter, b, and the number of external degrees of freedom per molecule, c. To allow calculation of the parameters of the high molecular weight components, whose critical constants and vapor pressure are unknown, a group-contribution approach is developed for a, b, and c. The extension to mixtures is achieved by applying Huron-Vidal mixing rules. A modified Uniquac model is used to evaluate infinite-pressure activity coefficients. With the proposed method, the density of pure heavy components (such as n-hexadecane and pentaerythritol esters) is predicted as a function of temperature. Vapor-liquid equilibria calculations are presented for binary mixtures between several hydrofluorocarbons and pentaerythritol esters or hexadecane; a comparison with the results obtained by available models is also outlined.

• OSTI ID: 352675
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 5 Vol. 38; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
40 CHEMISTRY
CHLOROFLUOROCARBONS
EQUATIONS OF STATE
EQUILIBRIUM
FLUORINATED ALIPHATIC HYDROCARBONS
LUBRICATING OILS
MATERIAL SUBSTITUTION
REFRIGERANTS