Experimental and simulation analysis on by-products of treatment of SF6 using dielectric barrier discharge

Dielectric barrier discharge (DBD) plasma is a simple technology with low energy consumption and high efficiency for treating gas waste. In this paper, DBD was used to remove greenhouse gas sulfur hexafluoride (SF
6
). The degradation by-products of SF
6
were detected and they were SOF
4
(with highest concentration), SO
2
F
2
, SOF
2
, and a limited amount of SO
2
. The thermodynamics associated with DBD degradation of SF
6
at ambient temperature and atmospheric pressure was studied. The calculations showed that SF
6
molecules can be dissociated step by step by high-energy electrons. The effect of traces of water vapor in the reactor was considered. Free radicals such as H and OH can be generated by the dissociation of H
2
O, which requires about 96.64 kcal/mol. Once SF
6
and H
2
O molecules breaks down, their intermediate products can react with each other easily to form the final by-products, including SO
2
, HF, SOF
2
, SOF
4
and SO
2
F
2
. Most of these formation reactions were thermodynamically favorable. The reaction pathways and reaction energy well explained the difference in the yield of by-products in the DBD experiment.