Yogesh Waghmare1, Richard G. Rice2, and F. Carl Knopf1. (1) Chemical Eng., Louisiana State University, South Stadium Road, Baton Rouge, LA 70803, (2) Chemical Engineering, Louisiana State University, Dept. of Chemical Engineering, LSU, Baton Rouge, LA 70803
Previously(1,2,3) it has been shown that low amplitude (0.5 mm– 2.5 mm) oscillations at moderate frequencies ( 0 – 25 Hz) can be used to improve the bubble column performance. Available literature on oscillating bubble columns mainly focuses on air-water system (Viscosity ~ 1 cP). In present work, effect of oscillations on the mass transfer coefficient in the oscillating bubble column was studied for various CMC solutions in the viscosity range 1 - 50 cP. Similar to previously reported results for air-water system, viscous systems exhibit initial increase in mass transfer coefficient as a function of frequency and then reach a plateau. This plateau behavior can be attributed to Bjerknes forces acting on a bubble. The shape of the curve for mass transfer coefficient vs frequency remains unchanged for viscous systems, but the absolute value of the mass transfer coefficient decreases as a function of increasing viscosity.
1.Knopf FC, Ma J, Rice RG, Nikitopoulos D. Pulsing to improve bubble column performance: I Low gas rates. AIChE J. 2006;52:1103-1115. 2.Knopf FC, Waghmare Y, Ma J, Rice RG. Pulsing to improve bubble column performance: II Jetting gas rates. AIChE J. 2006;52:1116-1126. 3.Waghmare YG, Knopf FC, Rice RG. A new theory to explain transport in pulsed-flow bubble columns: the Bjerknes effect. AIChE J. 2007; accepted for publication.