Hydrodynamic behavior of slurry bubble column at high solids concentrations

Hydrodynamics of a slurry bubble column have been investigated up to slurry concentrations of 40 vol.% and gas velocities of 0.26 m/s. High slurry con centrations represent high catalyst loading to increase reactor productivit y, while high gas velocities would be required to increase reactor throughp uts. The solid particles used are 35 mu m glass beads representing typical particle size for catalytic slurry reactors. The two important hydrodynamic parameters investigated are gas holdup and solids concentration profiles. The average gas holdups decreased with increasing slurry concentration but the rate of decrease slowed down for higher slurry concentrations. The anal ysis of axial gas holdup profiles indicated that decrease in gas holdup due to solids addition could be attributed to a decrease in bubble breakup rat es. The experimental gas holdups are compared with literature correlations and models. The axial distribution of slurry concentration followed the cla ssical sedimentation-dispersion model. Effects of gas velocity on axial sol ids distribution are found to be minimal over the range of gas velocities i nvestigated. (C) 1999 Elsevier Science S.A. All rights reserved.