Study On Mn₃O₄ Coating Enhanced Dielectric Barrier Discharge Degradation Of Benzene Series

As environmental pollutants,benzene series seriously endanger human health.As an emerging technology,low-temperature plasma technology is often used in organic waste gas treatment research due to its clean degradation products,simple operation,and high degradation efficiency,but it still has problems such as high energy consumption and residual O₃.In this paper,Mn₃O₄coated self-assembled low-temperature plasma reactor electrodes are used,using toluene,xylene,aniline,paint waste gas,etc.as probes,to carry out Mn₃O₄coated enhanced dielectric barrier discharge（DBD-M）degradation of benzene series,revealing High-voltage reaction field material conversion and benzene series degradation process,in order to improve the electrical performance of dielectric barrier discharge,and realize the application and promotion of plasma technology in the treatment of benzene series waste gas.In order to reveal the strengthening effect of Mn₃O₄on the degradation of benzene series by dielectric barrier discharge,the effects of Mn₃O₄coated electrode and Mn₃O₄/Al₂O₃load filling methods on the discharge performance of low-temperature plasma were compared and studied,and the electric discharge mode,discharge power,energy density,etc.were obtained by analysis.Performance parameters,detect and analyze the content of OH and O₃produced in the discharge space;use toluene as the degradation target to obtain different electrical parameters such as discharge power,discharge time,and air flow rate.In order to reveal the degradation law of toluene by DBD-M,investigate and explore the effects of discharge power,initial concentration,environmental humidity and other conditions on toluene degradation;use classical kinetics to reveal the kinetic characteristics of toluene degradation under different power and initial concentration conditions in the discharge system;With the help of GCMS,analyze the toluene degradation products in the discharge system,and then explore the mechanism of toluene degradation.In order to further understand the degradation energy efficiency of DBD-M for its benzene series,the discharge power,initial concentration,environmental humidity and other conditions were investigated for the degradation of xylene,aniline and paint source exhaust gas,and the discharge system was explored with the help of on-line detector and GCMS Changes in CO₂,NOX,O₃and other substances as well as degradation products of benzene series.Research indicates:（1）Electrical performance analysis found that the Mn₃O₄coating,Mn₃O₄/Al₂O₃filling and dielectric barrier no-load discharge waveforms are all sinusoidal and have burrs,indicating that the coating and filling will not affect the dielectric barrier discharge mode;when the discharge voltage is 13KV,The discharge power is Mn3O4coating（231.9w）>Mn₃O₄/Al₂O₃filling（215.5w）>dielectric barrier no-load discharge（184.8w）,and the energy density is Mn3O4 coating（9176J/L）>filling mode（8620J/L）>No load（7392J/L）,the system·OH production amount is Mn₃O₄coating（2.64mg/L）>Mn₃O₄/Al₂O₃filling（1.11mg/L）>Dielectric barrier no load（0.61mg/L）,The amount of O₃produced is in the order of dielectric barrier no-load（220.31mg/m³）>Mn₃O₄/Al₂O₃filling（151.43mg/m³）>Mn₃O₄coating（90.33mg/m³）,indicating that Mn₃O₄coating can enhance the electrical performance of dielectric barrier discharge It can increase the production of active particles and OH,reduce the residual O₃in the exhaust gas,and assist in improving the ability of organic waste gas treatment.（2）Compare the energy efficiency of toluene degradation by Mn₃O₄coating,Mn₃O₄/Al₂O₃filling and dielectric barrier no-load discharge,and optimize the appropriate electrical parameters of DBD-M:discharge voltage 13KV,background gas flow rate 1.5 L/min,discharge treatment 3 min;Under these conditions,the degradation rate of toluene with an initial mass concentration of 2000 mg/m³by Mn₃O₄coating is92.72%,which is 10.26%higher than that of dielectric barrier no-load discharge,indicating that Mn₃O₄with high oxygen vacancies on the surface contributes to the catalytic conversion of O₃,To promote the degradation of toluene.The energy efficiency study of toluene degradation by Mn₃O₄coating found that when the discharge power is 231.9w,the initial mass concentration is 710 mg/m³,and the ambient humidity is 40%,the toluene degradation rate can reach 92.73%.The degradation of toluene by DBD-M conforms to the first-order reaction kinetics.The kinetic model is y=0.49882x-0.73041（R²=0.997）.（3）The study on DBD-M discharge degradation of benzene series found that when the input power is 231.9w,the initial concentration is 710mg/m³,and the ambient humidity is 40%,the degradation rates of xylene,toluene,aniline and paint source exhaust gas are respectively Are 93.45%,92.37%,91.37%,90.53%;the degradation rate constant k of xylene,toluene,aniline,paint source waste gas is xylene（0.17899）>toluene（0.14163）>aniline（0.13987）>paint source waste gas（0.11671）,indicating that the degradation advantage of xylene is better than toluene and aniline.（4）Using an online monitor to analyze the changes in the concentration of CO₂,NOx,and O₃during the degradation of benzene series,it was found that the concentration of CO₂,NOx,and O₃in xylene,toluene,aniline,and paint source exhaust gas all increased first and then stabilized.The process value of NOx and O₃concentration is much lower than that of dielectric barrier no-load discharge,indicating that Mn₃O₄coating can effectively reduce O₃residue while improving the degradation of organic waste gas.Exhaust gas analysis found that no other secondary products were generated in the tail gas of xylene,toluene and aniline,and only some alkane substances remained in the exhaust gas from paint source exhaust gas treatment,indicating that the exhaust gas treated by DBD-M can clean and efficiently degrade pollutants.