Destruction of hexafluoroethane in a dielectric-packed bed plasma reactor

The destruction of hexafluoroethane (C 2 F 6 ), also known as R-116, was investigated in a nonthermal plasma reactor packed with dielectric pellets. The effects of the feed gas composition and the input power on the destruction of C 2 F 6 were examined. The feed gas composition was varied by changing the oxygen content, the argon content and the initial C 2 F 6 concentration. An increased input power led to increased C 2 F 6 destruction as a result of promoting the electron-molecule collisions to dissociate C 2 F 6 molecules. The addition of argon to the feed gas greatly improved the C 2 F 6 destruction by reducing the energy losses due to vibrational excitation and dissociation of N 2 molecules, while the increases in the oxygen content and the initial C 2 F 6 concentration decreased the destruction efficiency. The byproducts including CO 2 , CO, COF 2 , CF 4 , SiF 4 , NO 2 , and N 2 O were identified, and the destruction mechanisms were elucidated, referring to these compounds. The most abundant byproduct was found to be carbonyl fluoride (COF 2 ), indicating that it serves as an important medium to convert C 2 F 6 into CO 2 . The energy requirement for the C 2 F 6 destruction was in the range of 8.2–45.3 MJ/g, depending on the initial concentration.