Effect of superficial gas velocity on gas hold-up profiles in foaming liquids in bubble column reactors

Abstract

In an extension to our previous work [Chem. Eng. J. 84 (2001) 247], we continue our investigation in the present communication on the effect of superficial gas velocity on radial gas hold-up profiles for air-aqueous solutions of n-butanol. Radial variation of gas hold-up was investigated in 0.385 m i.d. bubble column using gamma ray tomography. The gas phase was air and the liquid phase comprised of aqueous solution of n-butanol of three different concentrations, 0.02, 0.2 and 0.5% v/v. The range of superficial gas velocities studied is 0.06-0.24 m/s. Two perforated sparger plates were used having the same free area (FA=0.42%) and two hole diameters (1 mm, multipoint sparger; 25 mm, single point sparger). The bubble size was found to reduce and the hold-up profiles were found to become flatter with an increase in butanol concentration and H_D/D ratio.