The gas density effect on mass transfer in bubble columns with organic liquids

Gas holdups and volumetric mass transfer coefficients in organic liquids (ethanol, 1-butanol, decalin, toluene) have been measured in a bubble column (0.1 m diameter, 3 different gas spargers) at 293-343 K. Wide ranges of the gas velocity (0.01-0.21 m s(-1)) and the gas density (0.19-46.7 kg m(-3)) are covered. The gas density effect is found to increase with the gas density and the gas velocity. This observation is in agreement with the theory of bubble breakage by Kelvin-Helmholz instability. Considering the additional literature data, new dimensionless correlations are developed that represent 687 gas holdups in 23 different liquids with 11.2% mean error and 673 mass transfer data in 31 liquids with 13.8% mean error. (C) 2001 Elsevier Science Ltd. All rights reserved.