Dependence of sintering temperatures of the BaTiO3 pellets on N2O generation characteristics in a packed-bed plasma reactor

Influence of the physical properties of BaTiO3 pellets upon N2O generation during NOx processing in the BaTiO3 packed-bed reactor has been investigated. The results show that the capability of the BaTiO3 packed-bed reactors for both NOx removal and low N2O generation can be improved by modifying the physical properties of BaTiO3 pellets in the process of their sintering. The crystallographic and surface structures, relative to the dielectric constant and specific surface area of the BaTiO3 pellets sintered in temperatures below 600 degreesC, become similar to those of paraelectrical materials. The changes in the BaTiO3 pellets properties affect the parameters of the discharge in the BaTiO3 packed-bed reactor. The discharge operates at a higher voltage and a lower electrical power when the BaTiO3 pellets sintered at temperatures lower than 600 degreesC are used. By optimizing the properties of BaTiO3 pellets, efficient NOx removal and low production of N2O in the packed-bed reactor are possible. When the BaTiO3 pellets sintered in temperatures lower than 600 degreesC were used, a 70% decrease in the total number of nitrogen oxide molecules (including NO, NO2 and N2O produced during the plasma processing) was obtained at an energy efficiency of 1-2 g [NO]/kWh. Using these BaTiO3 pellets also ensures low generation of N2O (below 10 ppm) during NOx processing. Thus, the optimum selection of BaTiO3 pellets enables the BaTiO3 packed-bed reactors to perform efficient NOx removal at low N2O generation without using catalysts and/or additional reductants. (C) 2001 Elsevier Science B.V. All rights reserved.