High-pressure phase equilibrium for carbon dioxide + ethyl n -butyrate binary system

Abstract

Vapor-liquid equilibrium data were measured for the carbon dioxide + ethyl n-butyrate (EB) binary system at high-pressures. Five isotherms are reported at (333.15, 343.15, 353.15, 363.15, and 373.15) K and pressures up to 121.75 bar. A static-analytical method with phases sampling was used. The new experimental results are compared with existing literature data and discussed. In order to provide a continuous and consistent description of the system phase behavior, unique sets of interaction parameters for different approaches with the Peng-Robinson (PR) equation of state (EoS) and classical van der Waals mixing rules were obtained. A constant kij value of -0.048 is recommended, providing an excellent description of the data reported in this work, especially for the liquid phase. Predictions are also compared with the other available literature data and discussed.