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.

A numerical simulation, including transport phenomena, is presented in this paper for the calculation of ozone generation in an oxygen-fed wire-to-cylinder ozonizer. The ozone density dependence on the first excited states of atomic and molecular oxygen and ozone is analysed, introducing three kinetic models. The influence of excited states on ozone production is shown as well as the correlation between the first excited state of atomic oxygen O(1D) and the second excited state of molecular oxygen O2(1 Sigma +g). Furthermore, these results confirm the validity of the plug-flow reactor hypothesis in the case of an oxygen-fed ozonizer.

The Oxygreen process is a new process based on wheat grain treatment by ozone (produced in situ), in a closed sequential batch reactor. The Oxygreen process offers a close, homogeneous, and controlled contact between the gas and the grain. It is proposed for use for wheat grain decontamination (insects, fungi, bacteria, mycotoxins, pesticides). It takes place in classical milling diagram, and occurs after grain cleaning and before milling. The aim of the study reported here was to determine if Oxygreen treatment could induce in the grain the formation of processing-related compounds, and if these compounds are specific or could be recognized as classical modifications already used in the cereal industry (milling, baking). Studies were performed in order to evaluate any effect of Oxygreen treatment on vitamins, ferulic acid, phytates, proteins, carbohydrates, and lipids. It was concluded that there was no detectable substantial difference between ozone-treated grains and the untreated ones, although some quantitative differences can occur. The more detectable differences concern concentration of free sugars, and inhibition of some oxidative enzymes. These quantitative differences are very slight compared to the modifications that occur in dough, after addition of oxidative products directly in flour, or during kneading and dough fermentation.

In this paper we present a numerical simulation for the calculation of ozone production in an oxygen-fed wire to cylinder ozonizer. We investigate the pressure, temperature, average flow velocity and multi-injection dependence. The results show that an oxygen-fed ozonizer can be modelled by a plug flow reactor: the thermal degradation of ozone along the z axis of the cylinder can also be observed.

The Oxygreen process is a new treatment approved by The French Food Safety Authority (AFSSA) as a processing aid for flour quality improvement, based on treatment by ozone, in a closed sequential batch reactor. This treatment takes place in the classical milling sequence, after the grain-cleaning step and before milling. The Oxygreen process could also be used for its properties in wheat grain decontamination (insects, fungi, bacteria, mycotoxins, storage insecticides residues). The aim of this study was to determine if Oxygreen treatment could induce in the grain the formation of processing-related substances, able to provoke adverse effects, after ingestion of the wheat and/or derived products, and to establish the safety of the Oxygreen process for animals and consumers. A four-week toxicity study, according to OECD guideline No. 407, was performed on Dark agouti rats fed exclusively with wheat grains, treated or untreated with Oxygreen. Clinical, haematological, blood biochemical, urinary and histopathological parameters were investigated during the study. The few modifications observed in animals given treated wheat were an increase of rectal temperature in females, a slight decrease of calcium concentration in males and slight decrease of certain blood cell number without clinical significances. This work shows that wheat treated by Oxygreen does not induce adverse effects in Dark agouti rats after oral administration. Therefore wheat and derived products from wheat, after Oxygreen treatment on grain, could be considered as safe for the consumer.