title: Integrated removal of NO and mercury from coal combustion flue gas using manganese oxides supported on TiO2.
abstract: A catalyst composed of manganese oxides supported on titania (MnOx/TiO2) synthesized by a sol-gel method was selected to remove nitric oxide and mercury jointly at a relatively low temperature in simulated flue gas from coal-fired power plants. The physico-chemical characteristics of catalysts were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses, etc. The effects of Mn loading, reaction temperature and individual flue gas components on denitration and Hg0removal were examined. The results indicated that the optimal Mn/Ti molar ratio was 0.8 and the best working temperature was 240°C for NO conversion. O2and a proper ratio of [NH3]/[NO] are essential for the denitration reaction. Both NO conversion and Hg0removal efficiency could reach more than 80% when NO and Hg0were removed simultaneously using Mn0.8Ti at 240°C. Hg0removal efficiency slightly declined as the Mn content increased in the catalysts. The reaction temperature had no significant effect on Hg0removal efficiency. O2and HCl had a promotional effect on Hg0removal. SO2and NH3were observed to weaken Hg0removal because of competitive adsorption. NO first facilitated Hg0removal and then had an inhibiting effect as NO concentration increased without O2, and it exhibited weak inhibition of Hg0removal efficiency in the presence of O2. The oxidation of Hg0on MnOx/TiO2follows the Mars-Maessen and Langmuir-Hinshelwood mechanisms.
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Shibo
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: yczhao@hust.edu.cn.
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Henan Institute of Metallurgy Co., Ltd., Zhengzhou 450053, China; Research Center of Quality Inspection, Analysis and Test of Henan Academy of Sciences, Zhengzhou 450008, China.
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: jyzhang@hust.edu.cn.
authors.forename: Junying
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Chuguang
authors.initials: C
authors.lastname: Zheng
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control*; D003031:Coal; D006358:Hot Temperature; D017895:Manganese Compounds / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D003031:Coal; D017895:Manganese Compounds; D010087:Oxides; C009495:titanium dioxide; D009569:Nitric Oxide; C027424:manganese oxide; D014025:Titanium; D008628:Mercury
keywords: Manganese; Mercury; Nitric oxide; SCR; Titania