저온플라즈마를 이용한 비CO2계 지구 온난화가스 분해 연구

Abstract

Nonthermal plasma created in a dielectric-packed bed reactor was applied to the destruction of CHF3 and C2F6. The effects of feed gas composition, flow rate and input power were examined and the destruction mechanisms were discussed. In the presence of argon, the CHF3 destruction was largely enhanced, because the reaction of argon ion with CHF3 was very fast. The CHF3 destruction efficiency was highest for a small addition of oxygen (about 0.5%) and then decreased as the oxygen content increased. The increase in the CHF3 destruction efficiency with its initial concentration suggested that secondary destruction by the radicals formed from CHF3 played an important role. The increase in the feed gas flow rate lowered the CHF3 destruction efficiency, because both the residence time in the plasma reactor and relative amount of reactive species available for the destruction decreased. The analyses of the destructions products indicated that CHF3, was converted mainly into low molecular weight The electron impact dissociation is the key process for initiating the C2F6 destruction, which depends on the electron energy and concentration. Thus, as the input power was increased by increasing the applied voltage, the destruction efficiency was greatly enhanced. The increase in the oxygen content decreased the C2F6 destruction because a portion of the electrical energy delivered to the plasma reactor was consumed to form oxygen-containing byproducts. The addition of argon enhanced the C2F6 destruction, probably because the electron energy density distribution was shifted to favorable conditions. Regarding the effect of the initial C2F6 concentration, the decrease in the destruction efficiency with increasing initial C2F6 concentration was more significant in the absence of oxygen than in the presence of it. Judging from the distribution of these destruction products, COF2 is the key intermediate compound leading to the formation of CO2.