Effects of properties of manganese oxide-impregnated catalysts and flue gas condition on multipollutant control of Hg0 and NO.
This research investigated the effects of manganese oxide (MnOx) impregnation on the physical/chemical properties and multi pollutant control effectiveness of Hg(0) and NO using a V2O5-WO3/TiO2-SiO2 selective catalytic reduction (SCR) catalyst. Raw and MnOx-treated SCR samples were bean-shaped nanoparticles with sizes within 10-30 nm. Impregnating MnOx of ≤ 5 wt% caused limited changes in physical properties of the catalyst. The decrease in surface area when the impregnated MnOx amount was 10 wt% may stem from the pore blockage and particle growth or aggregation of the catalyst. Mn(4+) was the main valence state of impregnated MnOx. Apparent crystallinity of MnOx was not observed based on X-ray diffraction. MnOx impregnation enhanced the Hg(0) oxidation and NO/SO2 removal of SCR catalyst. The 5 and 10% MnOx-impregnated samples had the greatest multi pollutant control potentials for Hg(0) oxidation and NO removal; however, the increasing SO2 removal that may be mainly due to SO2-SO3 conversion should be cautioned. HCl and O2 greatly promoted Hg(0) oxidation. SO2 enhanced Hg(0) oxidation at ≤ 200 ppm while NO and NH3 consistently inhibited Hg(0) oxidation. Elevating flue gas temperature enhanced Hg(0) oxidation. Overall, MnOx-impregnated catalysts show stable and consistent multi pollutant removal effectiveness under the test conditions.
Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan.
Chun-Hsiang
CH
Chiu
Graduate Institute of Environmental Engineering, National Taiwan University, No. 71, Chou-Shan Rd., Taipei 106, Taiwan. Electronic address: hchsi@ntu.edu.tw.
Hsing-Cheng
HC
Hsi
Department of Chemistry, National Cheng-Kung University, No. 1, University Rd., Tainan 701, Taiwan.
Hong-Ping
HP
Lin
Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan.
Tien-Chin
TC
Chang
D000395:Air Pollutants, Occupational / Q000032:analysis*; D002384:Catalysis; D005740:Gases / Q000032:analysis*; D017895:Manganese Compounds / Q000737:chemistry*; D017669:Mercury Compounds / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D010087:Oxides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D014025:Titanium / Q000737:chemistry; D014414:Tungsten / Q000737:chemistry; D017968:Vanadium Compounds / Q000737:chemistry; D014961:X-Ray Diffraction
D000395:Air Pollutants, Occupational; D005740:Gases; D017895:Manganese Compounds; D017669:Mercury Compounds; D010087:Oxides; C507641:TiO2-SiO2; D017968:Vanadium Compounds; C027424:manganese oxide; D012822:Silicon Dioxide; C511604:tungsten oxide; C066075:vanadium pentoxide; D014025:Titanium; D009609:Nitrous Oxide; D009584:Nitrogen; D014414:Tungsten
DeNO(x) catalyst; Elemental mercury; Flue gas composition; Manganese oxide; Multipollutant control