Maleic Acid Ozonation: Reactor Modeling and Rate Constants Determination

Abstract

This work is related to ozone treatment of organic wastes, a gas-liquid reaction. A model has been developed that accounts for mass transfer from the gas to the liquid and for the kinetics of chemical reactions. The theoretical approach of the model firstly refers to the film theory enhanced by a new parameter, the depletion factor. This method allows the part of the reaction occurring within the film and that occurring within the bulk to be distinguished. In relation with the first part of the model, the second part allows the overall behavior of a gas-liquid reactor with time to be described. The model is validated by a set of experiments on maleic acid ozonation in a semi-batch reactor.

Ozonation of Crotonic Acid Solutions: Comparison of Two Methods for the Determination of the Rate Constant

“…A trial-and-error procedure was then applied to determine the kinetic rate constant k 2 by using Equations [4], [6], [7], and [9] for the film model and Equations [5], [6], [8], and [9] for the Danckwerts model. This procedure led to the best value of k 2 , that minimizes the sum of the squared differences between experimental and calculated values of the ozone absorption rates at different reaction times for a given experiment.…”

“…The ozone absorption rate was thus obtained by applying Equation [3], where the enhancement factor E appears which characterizes the mass transfer acceleration by the chemical reaction. Depending on the mass transfer model under consideration, the ozone absorption rate was written as Equation [4] (film model; Van Krevelen and Hoftijzer, 1948) or as Equation [5] (Danckwerts model;De Coursey, 1974). In these expressions, two dimensionless numbers appear: the Hatta number Ha (Equation [6]) and the instantaneous enhancement factor E i (Equation [7] for the film model and Equation [8] for the Danckwerts model).…”

Mathematical Model for Monitoring Gas-Liquid Reactors by Means of Continuous Flow Analysis

“…On the other hand, in the Global Model it is assumed that only the reactant BIT is being pumped in the CFA tube (see Equations [2][3]). This is only valid in the case of fast ozonation kinetics, when concentration of ozone in the liquid bulk is negligible.…”

Ozone absorption in a mechanically stirred reactor

“…(1) and (3), G and L represent the gas and liquid volumetric flow rates, respectively, and c G and c L the ozone concentration in the gas and liquid phase, respectively. In the case of distilled water r L represents the ozone self-decomposition rate.…”

“…[1][2][3][4][5][6][7][8][9][10][11] The influence of pH and ionic strength of the liquid phase on the equilibrium ozone concentration was also considered. [1][2][3][4][5][6][7][8][9][10][11] The influence of pH and ionic strength of the liquid phase on the equilibrium ozone concentration was also considered.…”