Semi-theoretical prediction of volumetric mass transfer coefficients in bubble columns with organic liquids at ambient and elevated temperatures

Abstract

A semi-theoretical approach for predicting k L a values (referred to liquid volume) in 18 organic liquids [acetone, aniline, 1-butanol, benzene, cyclohexane, decalin, 1,2-dichloroethane, 1,4-dioxane, ethanol (96%), ethylacetate, ethylbenzene, ligroin, methanol, nitrobenzene, 2-propanol, tetralin, toluene, and xylene] at various operating conditions (including elevated temperatures and pressures) was developed. It was found that the approach is applicable regardless of the hydrodynamic regime (at u G ≤ 0.1 m/s). Temperatures up to 353 K and pressures up to 0.5 MPa were tested. Two different distributors (multiple-hole and single-hole type) were employed. The liquid-phase mass transfer coefficient k L was calculated theoretically from the penetration theory on the basis of original definition of gas-liquid contact time. The interfacial area a was defined with respect to the liquid volume. It was found that their product k L a must be multiplied by some correction factor in order to take account of the non-spherical (ellipsoidal) shape of the bubbles. When the correction term is correlated to both the Eotvos number (Eo) and the dimensionless temperature ratio, 198 experimental k L a values can be fitted reasonably well (average relative error 9.3%).