Plasma-assisted abatement of SF ₆ in a dielectric barrier discharge reactor: investigation of the effect of packing materials

Abstract

Abstract The greenhouse gas hexafluoride (SF 6 ) and its degradation is a research hotspot in the environmental field. In a double-layer dielectric barrier discharge reactor, the degradation process of SF 6 was studied when packed in glass beads or γ -Al 2 O 3 pellets as well as with no packing system. The results show that the packing materials changed the physical characteristics of the discharge, increasing the equivalent capacitance and discharge power and leading to the generation of more active particles and high-energy electrons. Additionally, the two packing materials effectively improved the degradation removal efficiency (DRE) and energy yield (EY) of SF 6 . In the γ -Al 2 O 3 system, 2% SF 6 gas obtained a maximum DRE of 85.97% with a 110 W input power and the EY reached 9.17 g kWh −1 , far exceeding the case without packing. Moreover, the glass bead packing had no obvious effect on the degradation products, while the packing of γ -Al 2 O 3 particles promoted SO 2 production and reduced the formation of SOF 2 , SO 2 F 2 and SOF 4 . Meanwhile, in the γ -Al 2 O 3 system, the yield of SO 2 increased with increasing input power and some undesirable products such as SO 2 F 2 were reduced. These results show that the addition of suitable packing materials such as γ -Al 2 O 3 pellets can effectively promote the harmless degradation of SF 6 .