High-pressure viscosity measurements of oily substrates saturated with CO2 - (ID: 2036)

FORTUNATTI MONTOYA, MARIANA; HEGEL, PABLO E.; PEREDA, SELVA

Congreso; WCCE11 - CIBIQ2023 - GS04 - Global Symposium on Supercritical fluids and other High - pressure; 2023

Asociación Argentina de Ingenieros Químicos

Viscosity is an important thermophysical property in engineering design of reaction and separation processes. Particularly, in the design of packed columns the viscosity of the liquid phase influences the hydraulic of the column, as well as the mass transfer phenomena that governs the separation process. It is well known that the height of theoretical stage in the supercritical CO2 fractionation of vegetable oil-derivatives is highly dependent on the viscosity of the saturated liquid phase [1]. However, the viscosity of liquid mixtures at a given operating temperature and pressure is complicated to predict from pure component properties. Moreover, supercritical extraction processes involve the mixture of a liquid substrate and supercritical CO2 being a challenge to predict the viscosity behavior of these liquid mixtures. Assuming an ideal solution behavior to estimate properties of the liquid substrate in the column can has a major impact on the engineering design of a high-pressure fractionation column [2].In this work we shown the development of a high-pressure viscometer to carry out the viscosity measurement of saturated liquid mixtures for supercritical process engineering design. A high-pressure falling ball viscometer is used to measure the viscosity of saturated liquid mixtures of oily substrates + CO2. This technique has been used by other authors [3] to measure the viscosity of dense viscous fluids with supercritical solvents. We study the viscosity behavior of glycerol acetates saturated with CO2 (from 40 to 70 mol % CO2 concentration) and the viscosity of lemon oil saturated with CO2 (from 30 to 80 molar % CO2 concentration). The results show viscosity values between 0.9 mPa.s and 20 mPa.s at temperatures between 298 K and 333 K. The new viscosity data is correlated using a modified version of Litovitz equation.