Composite smoke denitration catalyst capable of oxidizing zero-valence mercury

Abstract

The invention provides a composite smoke denitration catalyst capable of oxidizing zero-valence mercury. The catalyst is composite oxide V2O5-CeO2-WO3 / TiO2 or V2O5-CeO2-MoO3 / TiO2 based on TiO2 as a carrier, wherein the weight proportion is as follows: the weight percent of TiO2 is 75-100, the weight percent of V is 1-1.5, the weight percent of Ce is 1-5, and the weight percent of W or Mo is 7.5-8.5. The preparation method comprises the following steps: depositing Ce(OH)3 on nano TiO2; dipping ammonium vanadate / ammonium molybdate; and drying and roasting so as to obtain the catalyst; or dipping a commercial SCR (selective catalytic reduction) catalyst in a cerous nitrate aqueous solution, and then drying and roasting. The catalyst provided by the invention maintains the denitraiton efficiency of the original SCR catalyst and simultaneously the oxidation rate of zero-valence mercury is obviously improved, and divalent mercury ions are captured in subsequent dedusting equipment and wet desulphurization system; and the application temperature range of the catalyst is wide, the combination control of emission amounts of nitrogen oxides and mercury in smoke of a fuel coal power plant can be achieved on the promise that the smoke purification facility of the fuel coal power plant is not added.

Description

technical field [0001] The invention relates to a composite flue gas denitrification catalyst capable of oxidizing zero-valent mercury and a preparation method thereof. x Selective catalytic reduction and catalytic oxidation of zero-valent mercury are mainly used for flue gas purification in coal-fired power plants, including nitrogen oxide and mercury emission control. Background technique [0002] Mercury is the only liquid metal at room temperature. It belongs to "carcinogenic, teratogenic and mutagenic" substances. The dry and wet deposition methods enter the soil and surface water, accumulate in the organism, and endanger human health and the ecological environment. 20% to 40% of mercury in nature comes from natural releases, 60% to 80% comes from human activities, and the mercury emitted by coal combustion flue gas accounts for 30% to 40% of the mercury emitted by human activities. my country's coal accounts for a relatively large proportion of primary energy, and th...

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Problems solved by technology

Neither activated carbon nor halide oxidizers are recyclable and therefore expensive

[0006] The Chinese patent with the publication number CN1698931 discloses a method for removing mercury from flue gas by catalytic oxidation, which uses transition metal oxides such as Fe, Co, Ni, Cu, and Mn to catalyze the oxidation of mercury, but requires a special catalytic reactor , increased coal-fired power plant flue gas purification facilities, increased investment, and the bigger defect is the large amount of SO present in the flue gas 2 It will affect the activity of these metal oxides, resulting in a gradual decrease in catalytic oxidation efficiency

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