Monte Carlo simulation for vapor-liquid equilibrium of binary mixtures CO2/CH3OH, CO2/C2H5OH, and CO2/CH3CH2CH2OH

Gibbs ensemble Monte Carlo simulations were performed to calculate the vapor-liquid coexistence properties for the binary mixtures CO2/CH3OH, CO2/C2H5OH, and CO2/CH3CH2CH2OH. The configurational bias Monte Carlo method was used in the simulation of alcohol. Density of the mixture, composition of the mixture, the pressure-composition diagram, and the radial distribution function were calculated at vapor-liquid equilibrium. The composition and the density of both vapor and liquid from simulation agree considerably well with the experimental values over a wide range of pressures. The radial distribution functions in the liquid mixtures show that CO2 molecules interact more strongly with methyl group than methylene group of C2H5OH and CH3CH2CH2OH due to the steric effects of the alcohol molecules.