Density and Viscosity of CO2 + Ethanol Binary Systems Measured by a Capillary Viscometer from 308.15 to 338.15 K and 15 to 45 MPa

摘要

Density and viscosity of CO2 + ethanol binary systems were measured by a high-pressure capillary viscometer at different ethanol mole fractions of 0, 0.067, 0.135, 0.203, 0.271, and 1 with temperature from 308.15 to 338.15 K and pressure from 15 to 45 MPa. The density and viscosity of the unitary and binary systems decrease when temperature increases and are found to increase with increasing pressure. Meanwhile, increasing ethanol mole fraction will increase the viscosity but make density reach to the maximum point. Based on these experimental data, volumes of mixing and viscosity deviation were calculated, which all showed negative values. Besides, the absolute value of deviation increases with increasing temperature or ethanol concentration but shows a negative relationship with pressure. Further, the perturbed-chain statistical associating fluid theory equation of state was introduced to investigate the correlation between densities in different systems by adjusting the binary interaction parameter (k(ij)). The viscosities of pure CO2, pure ethanol, and binary mixtures were correlated by Heidaryan function, Baylaucq function, and Song mixing rule, respectively. All these models show very good agreement with the experimental data obtained in this work.