Study On Dielectric Barrier Discharge Assisted Catalysis For Styrene Abatement

Air pollution is becoming one of the most challenging environmental issues in our country and has drawn growing concern, especially, the wide outbreak of haze in recent years. Volatile organic compounds (VOCs), a major kind of air pollutants, once emitted into the air, can cause effects such as secondary aerosols, therefore it’s essential to control the emission of it. The application of non-thermal plasma(NTP) for VOC abatement has the following weaknesses:poor energy efficiency, low mineralization degree and production of hazardous byproducts. In the last two decades, non-thermal plasma catalysis, which combines the advantages of both non-thermal plasma and catalysis, has been proved a very promising solution for the abatement of VOCs.This study is about the decomposition of styrene in a two-stage DBD (Dielectric Barrier Discharge) catalysis reactor. The main work and conclusions are as follows:(1)The catalysts MnOx/honeycomb and AgMnOx/honeycomb were prepared and combined with DBD to remove styrene in the air. The results showed that the plasma catalysis system performed better than DBD alone in terms of styrene conversion. When DBD alone is used, the styrene removal efficiency can reach 90% when SIE (specific input energy) is 165J/L while the styrene can be almost completely(>99%) removed in the DBD catalysis system at SIE of 98J/L.(2)The study of aerosol produced in the styrene removal process, including the particle size distribution, the average charge number and the effects of process parameters on the formation of aerosol. The results showed that, the smaller the diameter, the higher the number concentration. The aerosol particles carry charges, either positive or negative. Besides, the smaller aerosol particles carry fewer charges. Higher energy density, higher initial styrene concentration, lower gas flow rate and longer residence time can contribute to the formation of aerosol.(3)The study on the growth of aerosol. The experimental results showed that, within 41.8s, the number of smallest (diameter range 28-55nm) aerosol particles decreases while that of the other bigger particles increases. Meanwhile, both the total number concentration and total mass concentration become higher.(4)The XPS analysis showed that the components of the aerosol are mainly benzoic acid, benzaldehyde, long-chain hydrocarbons and so on.