Experimental Study On Planar Dielectric Barrier Discharge Assisted Catalysis For Toluene Abatement

Controling the emissions of volatile organic compounds (VOCs) is very significant to environment protection, because VOCs is one of the major air pollution sources. For the large flow rate and low concentration of VOCs, the application of traditional control technology is restricted in some aspects such as the investment cost, the operation cost and the removal efficiency.The non-thermal plasma technology (NTP) is considered to be a very promising way to VOCs treatment.However, the energy consumption of the process of VOCs treatment with NTP alone is high, while the undesired byproducts could be formed during the process. In order to overcome the above defects, people combine NTP with catalysis, which is proved to be more efficient.In this paper, the VOCs is treated in a two-stage DBD combining with catalysis system. The main research contents and conclusions are as follows:(1) The influence factors were studied in a home-made planar dielectric barrier discharge (DBD) reactor, which had a simple structure and the ability of discharging steadily. The experimental results showed that the planar DBD configuration performed well in discharging and ozone yielding.while it was assembled with ceramic as dielectric materials and meshy stainless steel as electrodes and the average discharge voltage was 10.5kV under 4mm discharge gap-(2) Comparing the toluene removal effiencies of DBD-catalysis system and DBD alone. The experimental results showed that the former one performed better and the toluene removal effiency of DBD combining with CoMnOx/ZSM-5 catalyst was 93.7% at SIE(specific input energy) of 328.3J/L while the toluene removal effiency of DBD alone was 37.5% at the same SIE.(3) The Mn-catalyst was loaded by Co and Ce, and then the toluene removal effiencies of different catalysts were compared. The experimental results showed that Co and Ce could improve Mn’s activity and maintain its activity. The toluene removal effiencies of MnOx/ZSM-5, CoMnOx/ZSM-5 and CeMnOx/ZSM-5 catalysts were respectively 68.1%,93.7% and 86.1%. The COX selectivities of these three catalysts were respectively58.8%,87.1% and 79.2%.(4) To study the influences of gas parameters during the VOCs treatment process by changing the gas parameters.And the experimental results showed that increasing the flow rate, the initial concentration of toluene and the humidity in the system would cause the decrease of toluene removal effiencies of the DBD-catalysis system.