Experimental Study On Degradatioh Of VOCs By DBD Synergistic Photocatalysts

Volatile organic compounds(VOCs),as secondary fine particulate matter(PM2.5)and ozone as an important precursor,will have a great impact on the natural environment and human health.Therefore,many scholars have begun to study the control scheme and governance technology of industry VOCs.On the basis of non-thermal plasma technology,plasma discharge was carried out in a wire-tube single dielectric barrier reactor to study the degradation of benzene,toluene,xylene,acetone and ethyl acetate,typical organic waste gas of spraying industry.On this basis,the introduction of granular photocatalyst and the doping modification of TiO2 photocatalyst were studied.The radiant light produced in the plasma is used as the driving source of the photocatalytic effect.By detecting the degradation efficiency,energy efficiency and influencing factors,the effect of the synergistic degradation of VOCs by plasma and photocatalysis is analyzed.Finally,a large number of ozone problems exist in the tail gas of the reaction,after the introduction of the plasma co photocatalyst on the basis of the plasma co photocatalysis.The ozone catalyst is used to further eliminate and utilize ozone in tail gas.The main research results are as follows:(1)The degradation of benzene,toluene,xylene and other organic waste gases by using low temperature plasma alone is better.At the discharge voltage of 21kV,the initial concentration of waste gas at 200 mg/m3,and the flow rate of 6cm/s,the maximum degradation efficiency of VOCs by single non-thermal plasma is about 60%and the energy efficiency is about 0.2g/(kg-h).(2)The particle photocatalyst impregnated with cubic Mn ion was coordinated with the NTP reactor by filling the particle photocatalyst.When the power supply frequency is 9kHz,the input power is 82 W(input voltage is 40 V,input current is 2.05 A),catalyst filling length is 10cm,gas velocity is 6 cm/s,initial concentration of exhaust gas is 200mg/m3,the maximum degradation efficiency of VOCs is 84 and energy efficiency is increased to 1g/(kg·h).(3)The degradation efficiency of VOCs by low temperature plasma is greatly affected by the initial concentration of exhaust gas and the airflow velocity,while the influence of catalyst can be reduced properly,under the same conditions,When the gas flow rate increased from 3cm/s to 18cm/s,the reduction in the degradation efficiency of p-xylene in the reactor filled with catalyst was reduced by 10 points compared with the plasma at low temperature alone,while the initial concentration increased from 50mg/m3 to 1000 mg/m3,which was reduced by 25%.(4)The monolithic ozone catalyst prepared from cordierite supported MnOx is used as plasma post-catalytic catalyst,which can reduce the ozone in the tail gas of the reaction by about 0.4?0.5mg/L,and the degradation efficiency of organic waste gas is increased by about 10%while the ozone is eliminated.Based on the low temperature plasma technology,the VOCs co-degradation analysis was carried out with the cooperation of particle photocatalyst,and a large number of ozone problems in tail gas were solved by introducing post-ozone catalysis.It provides a reference for the application of plasma photocatalysis technology in industrial waste gas purification.