MASS TRANSFER IN TWO- AND THREE-PHASE FLUIDIZED BEDS

Abstract

Mass transfer characteristics of two-(gas-liquid) and three-phase (gas-liquid-solid) fluidized beds in a 6. 64 cm-i. d. and 1. 8 m-high Plexiglas column have been determined in terms of gas-liquid mass transfer coefficient and interfacial area. In three-phase fluidized beds, carbonate/bicarbonate buffer solution, carbon dioxide and glass beads of three sizes were used as the liquid, gas and solid phases, respectively. The effects of liquid velocity (5. 4-13. 0 cm/s), gas velocity (1. 0-6. 5 cm/s), liquid-phase ionic strength (0. 5-3. 0 mol/l) and particle size (1. 7-6. 0 mm) on the mass transfer coefficient and the interfacial area were determined. The volumetric mass transfer coefficient, k//La, and the gas/liquid interfacial area, a, increased with increasing gas velocity, particle size and liquid-phase ionic strength in three-phase fluidized beds.