Study On The Mechanism Of Cooperative Treatment Of VOCs-O₃ By Low Temperature Plasma Technology

Since the 21st century,China’s rapid economic development has brought about the destruction of the ecological environment,Which has become a matter of close concern to Chinese scientists.The main task of air pollution prevention and control include the control of volatile organic compounds(VOCs).At present,low temperature and low ionization technology is one of the most promising technologies,but the removal of VOCs by this technology is often accompanied by the production of ozone(O3).The research on the removal of VOCs by low-temperature plasma while paying attention to the emission of O3 has important guiding significance of the development of practical environmental protection.In this paper,xylene is used as simulated gas and the catalyst carrier is selected γ-Al2O3 pellet’s,FeOx,MnO,CeOx and CuOx were used as active components to explore the effects of power,oxygen flux,initial concentration of xylene,amount to catalyst support and different metal oxides on the synergistic treatment effect of VOCs-O3 in the process of synergistic treatment of VOCs-O3 by low-temperature plasma combined with supported catalyst.Experimental results show that:(1)the greater the discharge power of the lowtemperature plasma,the better the removal effect of xylene.When the discharge power is 70 W,the oxygen flux is 15%,and the initial concentration is 600 ppm,the removal rate of xylene reaches 64.41%,and the ozone production is only 125.21 ppm,which is the highest co-processing efficiency of VOCs-O3 under the comprehensive consideration of this performance.(2)Under the condition of optimal low-temperature plasma performance,the particle size of the γ-Al2O3 carrier is 4-6 mm,and the total removal rate of xylene can reach 73.93%and the ozone inhibition rate is 66.45%when the dosage is 6g,and the system synergistic treatment effect is the best.Specifically,the smaller the particle size of the carrier,the better the removal effect of xylene,and the positive effect on the production of O3 plays a certain degree.(3)MxOy/γ-Al2O3 supported catalysts prepared by equal volume impregnation method and lowtemperature plasma co-processing VOCs-O3 found that the removal efficiency of xylene was from high to low:FeOx/γ-Al2O3>MnOx/γ-Al2O3>CuOx/γ-Al2O3>CeOx/γAl2O3>γ-Al2O3>blanks;the ozone inhibition rates were from high to low:MnOx/γAl2O3>FeOx/γ-Al2O3>CeOx/γ-Al2O3>CuOx/γ-Al2O3>γ-Al2O3>blank.(4)The catalytic effect of the catalyst made by the step-bγ-step impregnation method is better than that of the co-impregnation method by the two-way composite metal oxide catalyst Fe@Mn/γ-Al2O3 and Fe-Mn/γ-Al2O3 by the combined low-temperature plasma synergy.In the co-catalytic process,the total removal rate of xylene can reach 94.88%,and the ozone inhibition rate can reach up to 84.1%.