An extension of the group contribution model for thermodynamic and transport properties of dilute gases

Abstract

Earlier work of the group contribution method presented by Oh and Campbell [Oh and Campbell, 1997] for prediction of second virial coefficients and dilute gas transport properties has been repeated with a new set of normal alkane second virial coefficient data (methane, ethane, propane, and normal pentane critically compiled by Dymond and Smith [1980], normal hexane recommended by Dymond et al. [1986], and the recommendation for normal butane, heptane and octane updated by Tsonopoulos and Dymond [1997]). This method has been extended to molecular linear gases (carbon monoxide, oxygen and hydrogen) and to alkanes-gases mixtures. The functional group parameters were revised from the simultaneous regression of second virial coefficient and viscosity data. Group parameters values (CH0, CH1, CH2, CH3, CH4, double-bonded CH1 double-bonded CH2, N2, and CO2 groups) and 8 binary group interaction parameters (kN2-CH0,GC,kN2-CH1,GC, kN2-CH2,GC, kN2-CH3,GC,;kCO2-CH0,GC,kCO2-CH1,GC,;kCO2-CH2,GC, andK CO2-CH3,GC were revised. New group parameter values are given for gases beyond those presented earlier (CO, O2 and H2) and 19 group binary interaction parameter ValueS (kN2-CH1D, GC,kN2-CH2D,GC;kCO2-CH1D,GCkCO2-CH2D,GC;kCO-CH1,GC,kCO2-CH2,GC,kCO-CH3,GC, kCO-CH1D,GC,kCO-CH2D,GC,kO2-CH0,GC,kO2-CH1,GC,kO2-CH2,GC,kO2-CH2,GC,kO2-CH3,GC,kH2-CH0,GC,kH2-CH1,GC, kH2-CH2,GC,kH2-CH3,GC,kH2-CH1D,GC,kH2-CH2D,GC are presented for hydrocarbon mixtures with gases. Application of the model shows that second virial coefficient data can be represented with results comparable to those obtained by Oh and Campbell [1997] and by the corresponding states method of Tsonopoulos [ 1974]. The accuracy of the model in viscosity and diffusion coefficient predictions of dilute gases is comparable to the methods of Lucas [1980] and of the Fuller method [Fuller et al., 1966].