Dependence of sintering temperatures of the BaTiO 3 pellets on N 2O generation characteristics in a packed-bed plasma reactor

Abstract

Influence of the physical properties of BaTiO 3 pellets upon N 2O generation during NO x processing in the BaTiO 3 packed-bed reactor has been investigated. The results show that the capability of the BaTiO 3 packed-bed reactors for both NO x removal and low N 2O generation can be improved by modifying the physical properties of BaTiO 3 pellets in the process of their sintering. The crystallographic and surface structures, relative to the dielectric constant and specific surface area of the BaTiO 3 pellets sintered in temperatures below 600°C, become similar to those of paraelectrical materials. The changes in the BaTiO 3 pellets properties affect the parameters of the discharge in the BaTiO 3 packed-bed reactor. The discharge operates at a higher voltage and a lower electrical power when the BaTiO 3 pellets sintered at temperatures lower than 600°C are used. By optimizing the properties of BaTiO 3 pellets, efficient NO x removal and low production of N 2O in the packed-bed reactor are possible. When the BaTiO 3 pellets sintered in temperatures lower than 600°C were used, a 70% decrease in the total number of nitrogen oxide molecules (including NO, NO 2 and N 2O produced during the plasma processing) was obtained at an energy efficiency of 1–2 g [NO]/kWh. Using these BaTiO 3 pellets also ensures low generation of N 2O (below 10 ppm) during NO x processing. Thus, the optimum selection of BaTiO 3 pellets enables the BaTiO 3 packed-bed reactors to perform efficient NO x removal at low N 2O generation without using catalysts and/or additional reductants.