Enhanced Degradation Of Benzene In A Surface-packed Bed Hybrid Plasma Discharge Reactor Combined With Catalysts

Volatile Organic Compounds (VOCs Volatile Organic had, abbreviation) is the dust, SO2, NOx again after a major environmental pollutants, the harm to human health and fauna. Discharge plasma can produce some special physical and chemical substances, such as OH, O3, O and UV etc, effective treatment VOCs. This paper is aimed at discharge plasma VOCs processing mineralization efficiency is low, the problem of low efficiency of energy utilization, studied along the surface-packed bed hybrid discharge plasma and plasma catalyst for VOCs treatment effect, analyzes the by-products and carbon balance mechanism problem, for the next step further research provides a basis. The main research results are as follows:(1) Compared with surface discharge and packed-bed discharge, the surface-packed bed hybrid plasma discharge was more beneficial to remove VOCs, and the removal efficiency of benzene (initial concentration of 107 ppm) was 16%,63% and 77% with the specific input energy (SIE) of 765 J/L.(2) The electrode structure of the hybrid discharge plasma reactor was changed by changing the diameter of steel spring and the glass beads. The results showed that increases the spring diameter, reduces the electrode gap, increases discharge intensity and the discharge power could enhance the degradation of benzene. Reducing glass beads could improve the degradation efficiency of benzene.(3)γ-Al2O3 is a kind of catalyst carrier which used in the reactor. the position of catalysts, catalyst varieties and the loading of catalysts were studied. The result showed that the different position of catalysts in the reactor, the order of benzene degradation efficiency is: Bottom> Middle> Front. Ag/γ-Al2O3 catalyst showed the highest catalysis, the best loading of Ag and Mn is 15% and 10%, respectively.(4) When the experimental condition was at the gas flow for 0.4 L/min, benzene of initial concentration for 107 ppm, Ag loading for 15%, energy yiled for 765 J/L, the degradation efficiency of benzene was 77% with surface plasma discharge, while the degradation efficiency of benzene was 96% with hybrid discharge plasma combined catalysts, and the energy utilization efficiency was from 1.0 g/kWh increased to 1.8 g/kWh.(5) The byproduct of the benzene was analysis using Fourier infrared (FTIR) and GC-MS. The main byproducts were hydroquinone, heptanoic acid,4-nitrocatechol, phenol and 4-phenoxy-phenol, etc. The results showed that the byproducts with hybrid discharge plasma and catalysts were more than plasma only, and the carbon balance and CO2 selectivity were improved with hybrid discharge plasma and catalysts.