(454c) Modeling the Ultrasonic Cavitation-Enhanced Removal of Nitric Oxide from Flue Gases In a Bubble Column Reactor

The removal of NOx by ultrasonic irradiation is a fairly new area. In our previous works we have looked at the effects of different variables on the absorption of NOx from flue gases in presence of ultrasound. The fractional conversions of NO were found to range from 60% to 85%, while complete removal of SO2 was observed for all the inlet gas concentrations studied. Aimed at a more fundamental understanding of absorption of NOx using ultrasound, a model for such system incorporating the mass transfer and kinetics approach based upon the rate constants for the reactions of NOx with ?OH radicals was developed. The model is based on the simultaneous absorption and reaction of NOx in the liquid phase with ?OH radicals generated due to ultrasonic cavitation. The dynamics of a single cavitation bubble with chemical reactions has been considered to predict the rate of generation of ?OH radicals. This coupled with the reactions describing the mass transfer of NO from gas to liquid phase and its subsequent reaction with ?OH radicals have been solved to get the total rate of absorption of NO in a sonochemical bubble column reactor. The effect of ultrasound on mass transfer coefficient has not been incorporated in the current model. Instead, the comparison of the model results for different mass transfer coefficients over the range found in the literature will be discussed. Models discussing liquid-phase reactions in the presence of ultrasound are abound in the open literature. However, reactive mass transfer models coupling ultrasonic cavitation are rare. This work and results that will be discussed are unique in that respect.