Concurrent measurement of high-pressure binary phase equilibrium, density and dynamic viscosity

Abstract

New equipment offering a novel combination of concurrent binary phase equilibria, saturated fluid density and dynamic viscosity determination, was developed. The setup (Pmax 30MPa; Tmax 393K) includes a variable volume view cell to determine bubble/dew points and density, with a quartz-crystal resonator to measure dynamic viscosity. Phase equilibrium is determined visually, using a synthetically known composition (SynVisVar). Uncertainties in measurements are 0.06MPa in pressure, <0.0005 in mass fraction, and 0.2 K in temperature. Density is calculated to within <0.003 of the value. The dynamic viscosity is determined by measuring the frequency shift over the quartz crystal, to within <0.01 of the value. Equipment verification was done using n-dodecane and benzene at 0.1–30MPa and 313–353K while contributing to available benzene literature. Binary equilibrium measurements were verified using CO2+ethyl tetradecanoate while presenting new data on the dynamic viscosity and density of the saturated binary phase.