A new type of DC atmospheric pressure glow discharge combined with thermal catalyst was applied to the removal of toluene. Our plasma reactor closed in the discharge chamber consists of a rectangular shaped duct, in which five pins and a plate with spherical craters are positioned. The inter-electrode distance is 12.7 mm. The discharge was initiated at high voltage up to 20 kV and applied current up to 3 mA. A Cu-Mn/Al 2 O 3 thermal catalyst (operated temperatures up to 300 • C) is placed in series with a discharge chamber. In this study, inlet concentration range of toluene was stable at 45 ppm. No influence of the toluene admixture was observed on the threshold currents. The highest removal efficiency detected was about 96 % (temperature 300 • C; voltage 17.9 kV; current 2.5 mA). The energy efficiency of the toluene removal process and the existence of a synergistic effect of the combined application of plasma and catalysis were investigated, with the aim to operate the catalyst at a lower temperature, i.e. at a lower energy cost. We tried to explain some plasmochemical processes, such as consignable influence of generated ozone on the final Volatile organic compounds (VOC) concentration as well.

In view of the increasingly wide range of applications, different approaches are nowadays being investigated to generate non-thermal plasmas operating at atmospheric pressure. In this paper the focus is on DC-excited atmospheric pressure discharges in air. The basic electrode configuration is that of a pin-to-plate corona. First, the convective stabilisation mechanism and the existence of a glow regime in this type of discharge are discussed. Next, the application potential is illustrated with examples from the fields of surface treatment and gas cleaning.PACS : 52.77.J