Investigation of Residence Time Distribution in Two-Phase Bubble Columns - Analysis and Problems.

Knowledge of residence time distribution (RTD) is necessary for scale up of experimental results from laboratory to technical reactors. Measurements of RTD of gas and liquid were made in a bench scale two-phase bubble column (superficial gas velocity about 7 multiplied by (times) 10** minus **3 m multiplied by (times) s** minus **1, liquid velocity about 4 multiplied by (times) 10** minus **4 m multiplied by (times) s** minus **1). Analysis of experimental RTD was made on the basis of the tanks in a series model. The mean residence time and the number of stages were estimated using first and second momentums of the RTD. A problem was the interpretation of the large values of mean gas residence time. The mathematical simulation and interpretation of this phenomenon was possible on the basis of absorption and desorption of the gas phase tracer in the liquid phase.