Ozone treatment with catalysts

Ecoclear A continuous process for destroying organic contaminants in wastewater by treatment with ozone in the presence of a proprietary catalyst. Developed in 1995 by Eco Purification Systems, The Netherlands. 

Many gas-fired compressors that pump natural gas through millions of miles of pipelines are also equipped with exhaust catalysts to clean emissions at moderate conditions. Even fast-food restaurants are being equipped with catalysts to eliminate odors from the cooking process. The most widely used treatment of exhaust pollutants is that of the catalytic converter present in the exhaust manifold that cleans emissions from the internal combustion engines of gasoline- and diesel-fiieled automobiles and trucks. As modem commercial passenger jets fly above 30,000 feet there is a need to destroy the few ppm ozone that enters the airplane with make-up air to ensure passenger and crew comfort and safety. Radiators on select... 

Ozone is industrially applied for water treatment either alone or in combination with hydrogen peroxide and/or activated carbon. Recent reviews describe improvements of the ozone technology, including combinations with catalysts and AOTs [33,34]. 

A much more frequently used reaction is the cleavage of unsaturated compounds to aldehydes (equations 98 and 99). Alkenes and cycloalkenes that possess one or two hydrogens at the double bonds are oxidized by ozone to ozonides, which have to be reduced to prevent a subsequent oxidation to acids by the excess oxygen atom. Reductions are carried out, usually without isolation of the ozonides, by catalytic hydrogenation over palladium catalyst [80, 81,1106] or Raney nickel [55] or by treatment with... 

The regeneration of Y-zeolite catalysts used in isobutane alkylation with C4 olefins was studied. The coke formed on these catalysts during this reaction needs temperatures higher than 500°C to be burnt off with air. Ozone was used in this study to eliminate most of the coke at a much lower temperature. After a treatment at 125 C with ozone, the small amount of coke remaining on the catalyst can be removed with air at 250°C. The ozone not only eliminates coke from the catalyst, but also modifies its burning characteristics as measured by Temperature Programmed Oxidation, shifting the peak to lower temperatures. This allows a combined treatment with ozone at 125°C followed by air at 250°C to restore the activity and stability of Y-zeolite catalysts for isobutane alkylation. 

Some Typical Combined Use of Ozone with Catalysts or with Other Processes in Water Treatment... 

Finally, XPS shows no traces of other elements. In particular, neither Cl nor S were detected, which is important since the PS particles contain sulfate groups and NaCl was added to the particle suspension during the preparation all of these elements can influence the catalytic activity dramatically [1]. In circumstances where the O2 plasma may be causing irreversible damage to the sample, care has to be taken, for example, to avoid volatilization of the catalyst (as with Ru). A milder way of removing the PS mask is to employ an UV/ozone treatment, i.e., irradiation of the sample, kept in pure O2 or air, with a UV lamp creating ozone [108],... 

Here, we give an example where the electrochemical and electrocatalytic properties of nanostructured Pt catalysts supported on glassy carbon, prepared with colloidal lithography, were tested with oxidation of preadsorbed CO, so-called CO-stripping, as a test reaction [99]. The Pt nanoparticles were prepared as described in Fig. 4.11, except that the polystyrene particles were removed by UV-ozone treatment. The particles had an average diameter of 122 11 nm and were about 40 nm high. There was no indication (by AFM... 

Aging of spirits involves oxidation. It is this reaction which one attempts to hasten by the processes devised for accelerated aging. Methods for aging spirits artificially fall into four main classes as follows (1) treatment with air, oxygen, or ozone (2) exposure to actinic rays (3) electrolytic treatment and (4) use of catalysts. Combinations of these methods are likewise employed. 

---