The Application Study Of Alkaline Gas-liquid Two-phase Gliding Arc Plasma Combined With TiO₂ In Flue Gas Desulfurization

As one of tne major sources or air pollutants,the emission of industrial waste gas containing NOx,SO₂,etc.is subject to increasingly strict supervision.Traditional exhaust gas treatment methods can no longer meet the increasingly stringent emission standards.Low temperature plasma treatingt exhaust gas is favored by researchers due to its high processing efficiency,the relatively simple experiment device,low secondary pollution,and so on.However,there are disadvantages such as high energy consumption and bottlenecks in processing efficiency.Thus,this paper presents a kind processing technology of photocatalyst synergistic gas-liquid two-phase gliding arc plasma to treat SO₂ exhaust gas.In this paper,SO₂ gas was selected as the object of treatment.TiO₂ catalyst supported by molecular sieve was prepared by both sol-gel method and impregnation method.A gas-liquid two-phase gliding arc plasma reactor was constructed based on both the two blade electrode reactor and supported photocatalyst.The reaction mechanism of co-processing was analysed,photocatalyst loading characteristics and the characteristics of gliding arc discharge were explored were characterized by means of experiment measurement method including scanning electron microscope,energy dispersive X-ray,and so on.The effects of different parameters on desulfurization efficiency,and so on,were investigated.It is believed that photogenerated electrons and hole pairs generated on the surface of TiO₂ catalysts react with H2O,OH-,and O₂ in the gas stream of the plasma to generate strong oxidizing properties such as hydroxyl groups and H2O₂ under the irradiation of ultraviolet photons in the gliding arc discharge plasma.The radicals,which promote the oxidation of SO₂ gas molecules,also increase the energy efficiency of the gliding arc discharge reaction.The catalyst was placed 1 cm away from the tip of the blade electrode,and the gliding arc discharge mode and plasma distribution characteristics were barely affected.The experiment results showed that with the increase of treatment time,the removal rate of SO₂ gas increased and eventually tended to be saturated.After processing time lasted for 10s,the treatment effect was satisfactory,the processing speed changed lowly,and prolonging the treatment time was no significance,just only reduced the energy efficiency.Increasing the loading times and amounts of TiO₂ photocatalysts can increase the surface area and thickness of TiO₂ films,at the same time,and promote the improvement of photocatalytic effects of TiO₂.However,more than 4 loading times and 25 g or more amount of supported catalyst placed reduce the surface area and light transmittance of the catalyst film,which is not conducive to the further improvement of the efficiency of catalytic synergy.In addition,the use of NaOH solution in the liquid phase increases the concentration of OH-ions.which is helpful for the absorption of SO3 molecules and also provides more sources of hydroxyl groups for the reaction zone.The results show that the supporting TiO₂ catalyst can form the significant synergistic reaction with the gas-liquid two-phase gliding arc discharge plasma under alkaline condiion.After adding the photocatalyst,the gas-liquid two-phase gliding arc discharge plasma can maintain the SO₂ gas removal rate of more than 90%in the range of 80 to 200 ppm,compared with neutral single gas-liquid two-phase gliding arc discharge plasma,the SO₂ removal rate improved 10%.And the energy utilization rate of the treating process is also significantly higher than the non-catalytic gas-liquid two-phase sliding arc and the gas-liquid two-phase dielectric barrier discharge plasma has a good desulfurization effect.In this paper,the cooperative method to deal with SO₂ helps to form complementary advantages of the two methods,overcome the deficiencies of the single treatment method,and provide new ideas for the improvement of the removal effect of industrial waste gas.