Industrial & Engineering Chemistry Research, Vol.35, No.3, 824-828, 1996
Measurement and Correlation of Packed-Bed Axial-Dispersion Coefficients in Supercritical Carbon-Dioxide
Axial dispersion coefficients of squalene, benzoic acid, and oleic acid were measured in packed beds using supercritical carbon dioxide as a solvent over the temperature range 313-333 K, pressure range 100-300 bar, and Reynolds number range 2-80. Measurements were performed under both horizontal and vertical flaw conditions, using a variety of particle sizes, bed diameters, and bed lengths. The axial Peclet numbers obtained for small particles (< 1 mm diameter) were an order of magnitude lower than literature data for gases and liquids at ambient pressures. The dimensionless correlation 1/Pe = 0.018/Re + 10/(1 + 0.7/Re) was found to correlate the data within experimental error. The dispersion coefficients for large particles (> 1 mm) could be satisfactorially predicted by literature correlations.