Numerical simulation of ozone axial and radial distribution in a cylindrical oxygen-fed ozonizer

Abstract

A numerical simulation including kinetics, transport phenomena and temperature gradient is presented to describe axial and radial distribution of ozone in an oxygen-fed ozonizer with cylindrical symmetry. The interdependence of three types of modelling (kinetics, hydrodynamics and electronic injection due to electrical corona discharge) is emphasized and comparisons are made with previous simpler models. The simulation is performed in the case of an industrial cylinder-to-cylinder device for which the temperature gradient is negligible, and in the case of a laboratory wire-to-cylinder ozonizer where an important radial temperature gradient is experimentally observed. Two values of pressure are considered: 760 Torr, where chemical kinetics dominates over diffusion effects, and 10 Torr where diffusion is dominant.

High-temperature simultaneous removal of acetaldehyde and ammonia gases using corona discharge

“…2(a). As temperature increases, the CH 3 CHO removal efficiency remains nearly 100% from room temperature to 200 8C because of the effect of O 3 and O K anion at low temperatures [13,17,18]. In contrast, the CH 3 CHO removal efficiency tends to significantly decrease above 200 8C because of less O 3 generated from O 2 and reduction of the mean residence time of the gas mixture inside the reactor at high temperature.…”

“…Since NO x formation can be attributed to the reaction of discharge-induced N radicals with O 2 [15,16], N radicals should also contribute to the removal of CH 3 CHO and/or NH 3 from both N 2 and air at high temperatures. In addition, in the removal from air, there should be the extra effect of O radicals produced by electron impact to O 2 and by O 3 decomposition [13,17,18]. Therefore, the removal efficiency from air at high temperatures should be enhanced by O radicals, though O 3 oxidation is not effective.…”

Pulsed Streamer Corona Reactor Characterization - Phase II

“…Ozone generation in pulsed corona reactors having point-to-plane and wire-cylinder geometries have been considered with discrete injection of electrons and also with time-varying electronic density (Pignolet et al, 1990;Loiseau et al, 1994). The shape of the electronic injection time profile did not affect the concentration profile of ozone production.…”

“…The shape of the electronic injection time profile did not affect the concentration profile of ozone production. The temperature gradient between the electrodes in the wire-to-cylinder geometry had a drastic effect on the electron densities near the wire directly through ozone destruction at high temperatures and indirectly by viscosity, which affects the velocity profile (Loiseau et al, 1994).…”

“…This method was similar to the model used by Loiseau et al (1994) for computing ozone production in a cylindrical oxygen-fed ozonizer. For example, Figure 5 shows the concentration profile of ozone computed by the code used in the present study that alternately employed the two reaction sets to simulate the pulse-on and pulse off aspect of the discharge.…”