Regeneration of the Waste Selective Catalytic Reduction Denitrification Catalyst by Nitric Acid Washing.

ABSTRACT: In this study, the waste V2O5-WO3/TiO2 denitrification catalysts from the coal-fired power plant were washed with water or nitric acid, followed by impregnating different contents of V2O5. The effects of the HNO3 concentration and the additional amount of vanadium on the low-temperature selective catalytic reduction denitrification activity were investigated under the condition of high concentration of SO2 and H2O. The catalysts were characterized by inductively coupled plasma optical emission spectrometry, X-ray powder diffraction , N2 adsorption/desorption, H2-temperature-programmed reduction, NH3-temperature-programmed desorption , Fourier transform infrared spectroscopy , and Raman spectroscopy. The evaluation results revealed that optimum activity was achieved by using 0.8 mol/L HNO3 solution and loading 1.60 wt % V2O5 to make the total V2O5 reach 2.3 wt %. The characterization results showed that nitric washing can remove most of the ammonium salts deposited on the surface of the waste catalyst and produce crystalline WO3, which can effectively inhibit the agglomeration of vanadium species in the process of impregnation. Furthermore, it can also increase the amount of oligomeric VO x , which can improve the denitration activity.

SUBMITTER: Cao Y 

PROVIDER: S-EPMC6788065 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature