Quasi-static measurement of equilibrium solubilities in SC fluids: a mass transfer criterion

In this paper a continuous quasi-equilibrium method was used to determine t he solubilities of or and beta-naphthol in supercritical carbon dioxide. Fo r the case of a packed bed extractor in which pure solid slabs were contact ed with the flowing fluid, the approach to equilibrium is judged in terms o f a modified Stanton number, in the region where fi ee convection effects a re dominant (low Reynolds number). Analysis of data from Tan and Weng [C.-S . Tan, J. Weng, Fluid Phase Equilib. 34 (1987) 37-48] and Anistescu-Tavlari des [G. Anitescu, L.L. Tavlarides, J. Supercrit. Fluids 10 (1997) 175-189;] for several solutes, as well as own data, show that quasi-static experimen ts provide the equilibrium solubility with negligible error. (C) 2000 Elsev ier Science B.V. All rights reserved.