Experimental study on thermal catalytic degradation of SF6 waste gas by phosphate and metal oxides

The SF6abatement strategies had received special attention due to the fact that SF6has very high global warming potentials and long atmospheric lifetime. The use of degradation method can effectively eliminate the greenhouse effect caused by SF6exhaust gas. In this paper, Zr3(PO4)4, AlPO4, NiO and Fe3O4were used as catalysts to degrade SF6gas (the volume ratio of SF6was 15% and the background gas was air) at 800 □. The concentration of SF6gas was detected by gas chromatograph to obtain degradation rate, the partial degradation products of SF6gas were quantitatively analyzed by gaschromatograph-mass spectrometer, and the main products detected were SO2F2, SOF2and SO2gas. Comparing the product formation characteristics of four groups of test products when phosphate and metal oxide were used as catalysts, the gas production of SO2was the most at the same temperature. When Zr3(PO4)4and AlPO4were used as catalyst, the SO2F2gas production reached dynamic equilibrium at 31300ppm and 2385ppm respectively after heating for 4h, and the generated SOF2gas presented a linear growth. When NiO and Fe3O4were used as catalyst, SO2F2and SOF2gases were both linearly increased. When Zr3(PO4)4was used as catalyst, compared with other catalysts, the amount of SO2F2produced was the largest. NiO had a good catalytic effect, and the degradation rate of SF6gas reached 27.07% within 12h. The main decomposition products were SO2F2, SOF2and SO2gas, which could be filtered out by lye, which was of great significance for reducing greenhouse gas caused by SF6exhaust gas emissions.