Ozone is a very reactive oxidant because of its electrophilic and nucleophilic reactions. Therefore, applications of ozone were traditionally used in disinfection, taste and odor controls, and color removal. The most recent applications of ozone, however, are for disinfection by-products (DBPs) and synthetic organic chemicals (SOCs) controls, and biological stabilization, or algal growth control.

Ozone is toxic to the respiratory tract and ocular mucosa following inhalation exposure. As would be expected, the primary target of airborne ozone is the lung, and it is also shown to cause adverse effects on the eye and nervous system. Accordingly, ozone has long been recognized as one of the hazardous air pollutants, and one of the criteria air pollutants.

The off-gas leaving the downstream of ozone contacting chamber may contain high levels of ozone.Its emission must be controlled or removed before discharging the effluent into the atmosphere. The most commonly used methods for removing ozone are thermal destruction, catalytic decomposition, and adsorption/decomposition on activated carbon. Many articles were presented regarding the methods of catalytic decomposition of ozone. Among the metal oxide and precious metal/support catalysts for the decomposition of ozone, MnO2 has been commonly used for treating the residual ozone in off-gas in laboratories, «while Pt/support catalyst in commercial applications. The work of Naydenov and Mehandjiev used pure oxygen to synthesize ozone for the decomposition test but did not report the activity of MnOj after prolonged use. Heck et al. noted the activity decline of Pt/ceramics for the decomposition of ozone in air at 422 K (149°C), 1 atm, but did not provide the ozone decomposition rate expression.

There are different ways of ozone decomposition, such as thermal, photochemical, and catalytic. The most preferable from the economic efficiency and capabilities of hardware design process is the catalytic decomposition of ozone.

Nowadays they are producing different kinds of catalyst. The most widely used bulk catalysts (spheres, pellets). ECAT Company produces unique catalysts based on polyurethane foam.

The main special feature of our technology is not development of original catalytic compounds, but the most efficient configuration and stabilization of catalytic a layer in space at nano-level (in defects of crystal structure of the secondary carrier) as well as at macro-level, using various features of primary carrier structure. Application of a catalyst based on foam materials allows to intensify energy — and mass — transfer at the surface, at the expense of efficient turbulization of the flow by carrier macrostructure that reduces thermal loading on the installation and surrounding materials, which in turn increases operational life and reduces costs. In aggregate, suggested nano-structural composite catalysts based on foam materials provide maximum activation of various catalytic processes.

The use of foam as a carrier is the main feature of the ozone decomposition catalyst produced by ECAT.Its unique net-cellular structure provides ultra-high permeability of the catalyst. Expanded support through a highly, spatially homogeneous three-dimensional cellular structure gives the catalyst a property of an extremely low flow resistance. Due to using of polyurethane as a basis for flexible and easy to get a deformable catalyst, which can be bent by arbitrary manner.

Source: http://www.tandfonline.com/doi/abs/10.1080/10934529709376647