Catalytic C3H6 Oxidation Triggered by Plasma
Y. -H. Song, W. S. Kang, D. H. Lee, and J. O. Lee
Korea Institute of Machinery & Materials, Korea
Abstract- Oxidation of C3H6 at low temperature has been investigated using a combined plasma-catalyst process. The plasma-catalyst reactor consisted of a honeycomb-structured monolith substrate, which was the same as the one adopted in the automobile industry, and a couple of wire-mesh metal electrodes. When high-voltage AC power was applied to the plasma-catalyst reactor, a stable plasma was generated in the gap between the electrode and the substrate. The geometrical configuration of the present plasma-catalyst reactor was categorized as a post-plasma catalyst reactor in which gases are oxidized in two separate processes; plasma oxidation occurs first, following which the emitted gases from the plasma reactor are treated in the catalyst reactor. Tests for C3H6 oxidation were conducted for temperatures that ranged from room temperature to 200ºC. When the operating temperature was lower than the light-off temperature of the catalyst, total hydrocarbon (THC) concentration dropped abruptly immediately following the plasma triggering. This reduced THC quickly recovered as soon as the plasma process was terminated. On the other hand, when the temperature was higher than the light-off temperature, the temporal variations of THC were relatively slower due to adsorption and desorption processes. Additional tests showed that the desorption process triggered by plasma competed with the oxidation process, which could even result in an increase of THC emission under certain operating conditions.
Keywords-Non-thermal plasma, honeycomb-structured catalyst, temporal evolution