Phase Behavior, Densities, and Isothermal Compressibility of the CO2 + Pentane + Acetone Ternary System in Various Phase Regions

Abstract

The phase behavior and critical parameters of the CO2 (1) + pentane (2) + acetone (3) ternary system with different compositions were determined experimentally, and their densities were measured in both the subcritical and supercritical (SC) regions. The isothermal compressibility (KT) at some typical conditions was calculated using the density data. It is demonstrated that the density is sensitive to pressure as the pressure approaches the critical point of the mixtures, i.e, KT is large and increases sharply. KT also increases significantly as pressure approaches the dew point or the bubble point at other compositions close to the critical composition. However, KT is very small and is not sensitive to pressure well above the dew point or the bubble point. When the composition is far from the critical composition, KT has small values, and the effect of pressure on KT is very small, even near the phase-separation point.