NO reduction using low-temperature SCR assisted by a DBD method

This paper discusses the removal of nitric oxide （NO） with low-temperature selective catalytic reduction driven by a dielectric barrier discharge with ammonia （NH3） as a reductant. We explored the effects of NH3, O2, temperature and water under different applied voltage on NO removal at atmospheric pressure. The results showed that when the gas concentration ration of NH3/NO was 0.23-0.67, the NO removal efficiency and the energy consumption was acceptable. The NO removal efficiency reached 84% under an applied voltage of 7 kV, 400 ppm NO and 90 ppm NH3 at a temperature of 150 ℃. Water vapor had a negative effect because NO formation reactions were strengthened and NH3 was oxidized directly rather than reduced NO molecules. The outlet gas components were observed via Fourier transform infrared spectroscopy for revealing the decomposition process and mechanism.

DBD coupled with MnOx/γ-Al2O3 catalysts for the degradation of chlorobenzene

This paper investigates the degradation of chlorobenzene by dielectric barrier discharge(DBD)coupled with MnOx/γ-Al2O3 catalysts.MnOx/γ-Al2O3 catalysts were prepared using the impregnation method and were characterized in detail by N2 adsorption/desorption,x-ray diffraction and x-ray photoelectron spectroscopy.Compared with the single DBD reactor,the coupled reactor has a better performance on the removal rate of chlorobenzene,the selectivity of COx,and the inhibition of ozone production,especially at low discharge voltages.The degradation rate of chlorobenzene and selectivity of COx can reach 96.3%and 53.0%,respectively,at the specific energy density of 1350 J l-1.Moreover,the ozone concentration produced by the discharge is significantly reduced because the MnOx/Al2O3 catalysts contribute to the decomposition of ozone to form oxygen atoms for the oxidation of chlorobenzene.In addition,based on analysis of the byproducts,the decomposition mechanism of chlorobenzene in the coupled reactor is also discussed.

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

A new combined reactor with Hg/Ar electrodeless ultraviolet(EDUV)activated by DBD for 3,4-dichlorodiphenyl ether abatement is presented.The effect of specific input energy and feeding gas component on 3,4-dichlorodiphenyl ether removal efficiency has been explored.Compared with a single DBD system,this new combined process performed a significant promotion on 3,4-dichlorodiphenyl ether abatement.Experiment results verified that active oxygen clearly contributed to the synergistic activity of DBD-EDUV system.Results of emission spectra showed that UV radiation of 253.7 nm could be detected in the DBD-EDUV system.Further,the products of DBD-EDUV process were analyzed via gas chromatographymass spectrometer(GC-MS)to reveal involved decomposition mechanism.