Study On The Degradation Of Paint Exhaust By Nonthermal Plasma Assisted Mn-Based Catalytic Method

The organic waste gas generated by the solvent volatilization in the coating process seriously jeopardizes the surrounding environment and human health.In addition to particulate matter,volatile organic compounds?VOCs?are also an important part of the exhaust gas.However,for low-concentration VOCs,the conventional technology has a large footprint and low processing efficiency,which limits its application to reduce low-concentration exhaust gas.In recent years,non-thermal plasma?NTP?has been recognized as a potential application technology for the reduction of VOCs.During NTP working alone,due to its low efficiency,and it is easy to produce by-products such as NOx and aerosol.In order to improve the degradation efficiency of VOCs,Mn-based catalysts have been widely used in combination with NPT technology.In this paper,the DBD module was combined with Mn-based catalyst to degrade VOCs in the exhaust gas of the coating industry,and a set of two-stage dual-chamber DBD discharge module synergistic catalytic reaction system with reflux system was designed.The main contents and results of this paper are as follows:Firstly,MnOx prepared with manganese nitrate as a precursor presented the great physicochemical properties,while MnOx doped with Ag exhibited the favourable crystal shape;the degradation of xylene by non-thermal plasma was achieved by a plate DBD device,SIE as the important discharged parameters was positively correlated with the degradation efficiency of xylene.When SIE=25J/L,after the introducetion of MnOx?MN?,the removal efficiency of xylene in PPC system was 94.1%,the selectivity of CO₂ was 80.1%,and the concentration of O₃ was 168.5ppm.The concentration of NO₂ was 38.4ppm;the loading amount of 15%by weight of MnOx?MN?was placed after DBD reator,and the removal efficiency of xylene presented the highest.Secondly,the mixture of xylene and toluene was degraded in the PPC system with recycled section.The removal efficiency of xylene was 96.1%,the removal efficiency of toluene was 90.3%,the selectivity of CO₂ was 79.4%,the concentration of O₃ was 48.9 ppm,and the concentrations of NO and NO₂ were 42.4 and 298.3ppm.The stability of the experimental system and the performance of freshed MnOx?MN?and used MnOx?MN?were investigated.Incomplete degradation of the contaminants can adhere to the surface of the catalyst for the reduction of pollutants removal efficiency.And the air-plasma can reactive the catalyst.Finally,the PPC system was used to degrade toluene,and the possible degradation pathways of the degradation of toluene were discussed.Provide feasibility and experimental basis for subsequent research.