(505b) Liquid Viscosity Measurements On CO2 Expanded Solvent Systems With A Falling Weight Viscometer Under Pressure

The expanded solutions that result from the addition of dense gases such as carbon dioxide to organic solvents have been utilized in research of fractionation, particle precipitation and reaction processes. The advancement in the understanding of these processes and their successful commercial scaleup are dependent upon a concrete knowledge of fluid properties. Fluid viscosity forms an integral part in the understanding of system hydrodynamics, heat and mass transfer. Fluid viscosities are also crucial during process optimization and the sizing of process equipment. With accurate viscosity values present, design flaws and process inefficiencies may be averted at an early stage. There is currently a large void in the knowledge of liquid viscosities for high pressure binary dense gas systems for a considerable range of mixture compositions.

Falling weight viscometers have been successfully used in the past to determine the viscosity of supercritical fluid mixtures, and hence this concept was extended to binary dense gas mixtures. A falling weight viscometer apparatus capable of operating at high pressure was constructed and the measurement of the viscosities of a variety of dense CO2/organic solvent liquid systems between 298 at 313 K was carried out. Experimental data obtained from the apparatus exhibited a very good degree of repeatability.