Gibbs ensemble Monte Carlo simulation for vapor-liquid equilibrium of binary mixtures CO2/C3H8, CO2/CH3OCH3, and CO2/CH3COCH3

Gibbs ensemble Monte Carlo simulations were performed to calculate the vapo r- liquid coexistence properties for the binary mixtures CO2/C3H8, CO2/CH3O CH3, and CO2/CH3COCH3. For all the molecules the potential between sites in different molecules was simply calculated by the Lennard-Jones potential. Density of the mixture, composition of the mixture, the pressure-compositio n diagram, the chemical potential of component, and the radial distribution function were calculated at vapor- liquid equilibrium. The composition and the density of both vapor and liquid from simulation agreed considerably w ell with the experimental values over a wide range of pressures. The radial distribution functions in the liquid mixtures showed that CO2 molecules te nded to form cluster with each other and C3H8 molecules also aggregated eac h other due to the weak interaction between CO2 and C3H8 molecule. However the interaction potentials between the same components were similar to thos e between the different components in the liquid mixtures CO2/CH3OCH3 and C O2/CH3COCH3.