Isothermal Vapor−Liquid Equilibria for Binary Mixtures of Carbon Dioxide with Hexyl Acetate, Cyclohexyl Acetate, or Phenyl Acetate at Elevated Pressures

Abstract

Isothermal vapor−liquid equilibrium phase compositions were measured for three binary systems of carbon dioxide with different C6-acetateshexyl acetate, cyclohexyl acetate, and phenyl acetateat temperatures from 333.15 K to 413.15 K and pressures up to 20 MPa. The solubility isotherm of the acetates in the vapor phase exhibits a minimum value at subcritical pressures of carbon dioxide. Henry's constants were calculated by fitting the Krichevsky−Ilinskaya equation to the isothermal equilibrium data. The constants increase with increasing temperature for these three binary systems. The new phase equilibrium data were correlated with the Soave−Redlich−Kwong, the Peng−Robinson, and the Patel−Teja equations of state. The Peng−Robinson equation with two-parameter (ka12 and kb12) van der Waals mixing rules is marginally better than other methods for the investigated systems.