Accurate selection of vapor-liquid equilibrium thermodynamic model is essential to the design and operation of CO2-C2H6 azeotrope separation process. On the basis of collected experimental data

the reliabilities of four types of cubic equations of state including vdW

RK

SRK and PR combined with vdW

Margles and CVD mixing rules for predicting vapor-liquid equilibrium properties of CO2 pure substance

CO2-C2H6 azeotrope and n-C5H12-CO2-C2H6 ternary system are evaluated according to the principle of vapor-liquid fugacity equilibrium. In addition

average absolute deviation is adopted to select cubic state equations. The results show that the SRK equation of state calculates the vapor-liquid equilibrium property of CO2 pure material with the highest precision. The PR equation of state combined with Margles mixing rule can accurately calculate the vapor-liquid equilibrium characteristics of CO2-C2H6 azeotrope system. However

for n-C5H12-CO2-C2H6 ternary system

the calculating accuracy of SRK combined with Margles mixing rule is obviously better than that of vdW

RK and PR. Furthermore

binary interaction parameters have obvious effects on the calculating accuracy of cubic equations of state for the mixture system. In order to improve the calculation accuracy

the binary interaction parameter is calibrated for all of the studied EOSs regarding CO2-C2H6 azeotropic system and n-C5H12-CO2-C2H6 ternary system.