Comparison of the Effect of H₂ and O₂ on SF₆ Degradation by Hot Plasma

SF₆ has good insulation performance and arc extinguishing performance, which is more and more widely used in the power industry, and its emissions are also rising year by year. SF₆ has a very high GWP value, 23,900 times that of CO₂, and it is almost impossible to decompose in nature, so the harmless degradation of SF₆ is extra important. In this work, we carried out flow degradation treatment of SF₆ through a degradation device with hot plasma torch as the core, which was developed and designed by ourselves. Meanwhile, the degradation rate, toxicity and corrosion of degradation products were compared and analyzed under the condition that H₂ and O₂ were used as active gases respectively. The results show that the degradation rate of O₂ as the active gas is up to 96.17%, and the degradation rate of H₂ is up to 99%. The results of gas chromatograph, DRX and FTIR showed that the components of SF₆ were S and HF in the presence of H₂, and the main degradation products of SF₆ were SO₂F₂, SO₂ and SOF₂ in the presence of O₂. Both of the degradation products with the two gases have certain toxicity and corrosion, so we added a lye pond at the tail of the device to conduct harmless treatment of harmful products. The composition of the gas after extraction of lye was determined, and the results showed that the lye could completely absorb HF and SO₂, while the absorption of SOF₂ and SO₂F₂ was incomplete. In addition, in order to avoid clogging the lye pool with S generated in the presence of H₂, we added a bag collector. In summary, we believe that H₂ has a better effect on SF₆ degradation than O₂,.