Study on harmless degradation of SF6 using water vapor-synergized Fe2O3-filled catalyst

Sulfur hexafluoride (SF6) gas is widely used in high-voltage gas-insulated equipment due to its excellent electrical insulation and arc-quenching properties. Given that SF6 is a strong greenhouse gas, its degradation treatment represents a fundamental solution to SF6 waste gas disposal challenges. This paper studies the effect of H2O synergistic Fe2O3 catalyst filling on the degradation of SF6 by dielectric barrier discharge plasma, focusing on evaluating the effectiveness of the harmless treatment following alkaline absorption of SF6 degradation products. Research indicates that the synergistic effect between Fe2O3 and H2O can enhance discharge power and promote the degradation reaction. The SF6 degradation rate is observed to increase as a function of the input power, while the energy yield gradually decreases. Under the conditions of a gas flow rate of 150 ml/min and the addition of 1% H2O, the maximum degradation rate of 2% volume fraction SF6 reaches 82.4% under an input power condition of 100 W, and the energy yield is 11.57 g/kWh, achieving the optimal degradation results. Under the influence of the Fe2O3 catalyst, the main decomposition products are SiF4, SO2F2, SOF2, and SO2. The participation of H2O promotes the formation of SiF4 and SO2 while inhibiting the production of SO2F2 and SOF2. After the main degradation products of SF6 were absorbed by NaOH alkaline solution, only a small amount of SO2F2 remained, while the other products were almost completely absorbed. This study provides a significant reference for the efficient and environmentally harmless degradation of SF6.