DeNOx process in flue gas combined with nonthermal plasma and catalyst

Catalysts were used to enhance NOx removal reactions by the nonthermal plasma from room temperature to high temperature (500 degrees C). The NOx removal rate was significantly affected by the type of the catalyst or the gas temperature. When the conventional three-way catalyst for automobiles was activated at 500 degrees C, nonthermal plasma was not effective in removing NOx. When hydrocarbons (ethylene) were added to the synthetic flue gas, zeolite catalyst became very active at high temperature. The combination effect of nonthermal plasma and catalyst was confirmed below 200 degrees C. More than 80% of NOx was removed from synthetic flue gas by the combination of zeolite catalyst and hydrocarbons without nonthermal plasma discharge at 500 degrees C. Nonthermal plasma treatment could be useful even at high temperatures, where catalytic reactions were dominant.