Measurement and modeling of viscosity of supercritical carbon dioxide/biomaterial(s) mixtures

The viscosities of a binary, supercritical carbon dioxide/methyl oleate (SC -CO2/MO, and a multicomponent, SC-CO2/anhydrous milkfat (AMF) system at 40 degrees C and over a pressure range of 10.6-25.0 MPa were measured in a hig h-pressure capillary viscometer. The experimental data, and data from the l iterature, were utilized in viscosity modeling with fly and Hanley's corres ponding states model for SC-CO2/biomaterial(s) systems. The modified Benedi ct-Webb-Rubin equation of state and a viscosity correlation with propane as the reference material were used. An adjustable parameter was added to the energy shape factor equation. This approach worked well for both the fluid and liquid phases of the SC-CO2/biomaterial(s) systems with an average abs olute deviation of 3-6%. Compared to the purely correlative Grunberg and Ni ssan model, this method has better predictive capability, while maintaining comparable accuracy.