Improved Modeling of BubbleColumn Reactors by Consideringthe Bubble Size Distribution.

Bioconversion of glucose to gluconic acid with glucoseoxidaseas enzyme was considered to occur in a bubble column reactor at 40°C, atmospheric pressure, and pH 5.5 while oxygen gas velocitywas varied in the homogeneous and transition regime in the range of0.0014–0.0112 m s–1. It was found that thesuperficial gas velocity has a positive effect on gas holdup, meanbubble size, and volumetric mass transfer coefficient, while the glucoseconcentration has a negative influence on these hydrodynamic parameters.The modeling of bubble column by considering the complete bubble sizedistribution in the governing equations was carried out in this work.The model was also solved by considering the single and double sizesof bubbles instead of complete bubble size distribution. It was shownthat the results of the model, considering the complete bubble sizedistribution, is in a good agreement with the experimental data, whilethe considered single and double bubble sizes cannot predict the experimentaldata of oxygen concentration in the reactor properly. It was alsofound that the superficial gas velocity has a positive influence onoxygen concentration while glucose concentration has negative influenceat low superficial gas velocity and positive influence at high gasvelocity. [ABSTRACT FROM AUTHOR]