Assessment of a Stirred-Cell Reactor Operated Semicontinuously for the Kinetic Study of Fast Direct Ozonation Reactions by Reactive Absorption

A jacketed stirred-cell reactor, operated semi continuously, was used to assess the kinetics of fast ozonation reactions by reactive absorption. The method was applied to the direct ozone reaction with resorcinol. A high resorcinol concentration was used to reach a steady state and to neglect byproduct accumulation. Thus, the mass-transfer rate and, consecutively, the reaction rate were deduced from the ozone mass balance in the gas phase. The gas- and liquid-phase mass transfer coefficients were previously measured directly through ozone absorption under appropriate conditions. The results emphasized the high sensitivity of the reaction rate constant to the ozone physicochemical properties, especially its solubility, which is controversial in the literature. Therefore, several correlations used to calculate the ozone solubility in water were considered to calculate the second-order reaction rate constant, which varied from 3.57-4.68 X 10(5) L mol(-1) s(-1) at 20 degrees C to 9.50-12.2 X 10(5) L mol(-1) s(-1) at 35 degrees C. The activation energy was in the range 35-59 kJ mol(-1) depending on the considered ozone solubility correlation. A sensitivity analysis is provided to assess the influence of the experimental conditions and ozone physicochemical properties on the model. Finally, the applicability of this method is thoroughly discussed.