Vapor-Liquid Equilibria of Mixtures Containing Alkanes, Carbon Dioxide,and Nitrogen

摘要

New force fields for carbon dioxide and nitrogen are introduced that quantitatively reproduce the vapor-liquid equilibria (VLE) of the neat systems and their mixtures with alkanes. In addition to the usual VLE calculations for pure CO_2 and N_2, calculations of the binary mixtures with propane were used in the force-field development to achieve a good balance between dispersive and electrostatic (quadrupole-quadrupole) interactions. The transferability of the force fields was then assessed from calculations of the VLE for the binary mixtures with n-hexane, the binary mixture of CO_2/N_2, and the ternary mixture of CO_2/N_2/propane. The VLE calculations were carried out using configurational-bias Monte Carlo simulations in either the grand canonical ensemble with histogram-reweighting or in the Gibbs ensemble.