Mathematical modelling of supercritical fluid extraction of liquid lanoline from raw wool. Solubility and mass transfer rate parameters

Abstract

A new mathematical model is presented for the supercritical fluid extraction of lanoline from wool using near-critical ethanol-modified CO2, using our previous experimental data. The model is intended to account for the extraction of lanoline at conditions well above its melting point (60–80 °C) and pressures up to 150 bar. The model parameters are a Henry-type fluid-to-liquid partition coefficient for lanoline, K = Cg/CL, and a fluid-side mass-transfer coefficient, kG. For Re ~1, K is independent of velocity and wool packing density, but increases with pressure (K = 4 - 15 × 10-4). kG is found to be independent of temperature; it increases with velocity, decreases with pressure, and increases with wool packing density. The values found are kG = 5.66 × 10-6 m/s (70 bar) and kG = 1.51 × 10-6 m/s (150 bar)