Phase Behavior, Densities, and Isothermal Compressibility of CO2 + γ-Valerolactone Systems in Various Phase Regions

Abstract

The phase behavior of CO2 and γ-valerolactone (GVL) has been measured using a high-pressure variable-volume view cell and a fiber optic reflectometer. The density of the binary mixture has also been measured, and the isothermal compressibility (KT) of the binary mixture was calculated from the density of the binary mixture. The phase transition points, bubble point, dew point, and critical point, have been measured on the range of GVL mole fraction from 0.01 to 0.15 and temperatures from (308.2 to 550.2) K. The density of the mixture is sensitive to the pressure near the critical point of the mixtures, and KT is also sensitive to the pressure when the pressure is close to the phase transition point, especially close to the critical point. When the pressure is much higher than the phase separation pressure or the composition is far from the critical composition, KT is very small and the effect of pressure on KT is very limited. The phase boundary data of the binary mixture can be correlated well by the Pen...