Abstract: A molecular thermodynamic model of gas solubility in nonpolar solvents has been established. The Helmholtz energy of liquid mixture is calculated through the following three steps. First, the pure components in standard state are mixed isothermally to form an ideal gas mixture. Then each molecule is inflated into a hard sphere with diameter σ. The corresponding Helmholtz energy change is calculated by using the Mansoori-Carnahan-Starling-Leland equation. Finally, the molecules are charged with LJ 12-6 potential to form the real liquid mixture, where the structure is described by an approximated radial distribution function gij(r)=H(r-r)+βδ(r-rj). Henry’s constants are then calculated from residual chemical potential.With the use of the same LJ parameters, this model can predict the computer simulation results of Henry’s constant quite well. In this respect, this model is superior to Pierotti’s theory. For practical systems, Henry’s constants of various gases in C_1—C_(20) alkanes and their isomers, naphthenes, aromatic hydrocarbons and liquified gases can be well correlated over a wide temperature range using only one adjustable parameter. The predictions for △H_(s1), △S(s1) and V_1 are also satisfactory.

摘要： A molecular thermodynamic model of gas solubility in nonpolar solvents has been established. The Helmholtz energy of liquid mixture is calculated through the following three steps. First, the pure components in standard state are mixed isothermally to form an ideal gas mixture. Then each molecule is inflated into a hard sphere with diameter σ. The corresponding Helmholtz energy change is calculated by using the Mansoori-Carnahan-Starling-Leland equation. Finally, the molecules are charged with LJ 12-6 potential to form the real liquid mixture, where the structure is described by an approximated radial distribution function gij(r)=H(r-r)+βδ(r-rj). Henry’s constants are then calculated from residual chemical potential.With the use of the same LJ parameters, this model can predict the computer simulation results of Henry’s constant quite well. In this respect, this model is superior to Pierotti’s theory. For practical systems, Henry’s constants of various gases in C_1—C_(20) alkanes and their isomers, naphthenes, aromatic hydrocarbons and liquified gases can be well correlated over a wide temperature range using only one adjustable parameter. The predictions for △H_(s1), △S(s1) and V_1 are also satisfactory.