Density and viscosity of CO2 + ethyl acetate binary systems from 308.15 to 338.15 K and 15 to 45 MPa

Abstract

Combined with a high-pressure vibrating-tube densimeter and capillary viscometer, the density and viscosity of CO2(1)+ethyl acetate(2) binary systems with x2 = 0.000, 0.036, 0.075, 0.117, 0.163, and 1.000 were measured under conditions of 308.15–338.15 K and 15–45 MPa. In addition, the volumes of mixing (ΔVm) and viscosity deviation (Δη) were also calculated. The results illustrate that the density and viscosity of all systems increased with decreasing temperature and increasing pressure. The viscosity of the binary systems increased with increasing ethyl acetate concentration, and the density reached a maximum point under high pressure conditions (40 and 45 MPa). Moreover, ΔVm was negative and found to be reduced with a temperature decrease and pressure increase. Δη was positive except for pressures at 15 MPa, and these were found to be improved when increasing the temperature and pressure. The PC-SAFT equation of state and the Toscani-Szwarc model were applied to predict and correlate the density of the systems. For viscosity, different types of models were used. The Chung-Lee-Starling model and TRAPP model were introduced to predict pure systems, the Song mixing rule was used for mixed system viscosity correlation, and the Baylaucq equation was applied for unitary and binary system viscosity correlation. Four types of statistical values (AAD, bias, SDV, and RMS) were used to evaluate these models for each system.