Cellular Mn-Ti-based catalyst for low-temperature selective catalytic reduction denitration reaction and preparation method and using method

Abstract

The invention discloses a cellular Mn-Ti-based catalyst for low-temperature selective catalytic reduction (SCR) denitration reaction, and a preparation method and a using method. The catalyst comprises the following components in molar percent: 40 to 60 percent of TiO2, 5 to 16 percent of MnO2, 3 to 7 percent of Mn2O3, 2 to 4 percent of Mn3O4, 2 to 8 percent of CeO2, 1 to 3 percent of V2O5, 0.5 to 1 percent of Se, 0.5 to 1 percent of Sb, and 0.15 to 1.5 percent of Bi. The preparation method comprises the following steps of: first preparing Mn-Ti catalyst powder by a hydrothermal method, and then preparing modified cellular Mn-Ti-based catalyst by processes such as extrusion forming, soaking and the like so as to improve the low temperature SCR activity and the sulfur poisoning resisting capability of the catalyst. Furthermore, the catalyst prepared by the method has the advantages of high mechanical strength, high dispersibility of active substances and difficult sintering, can be applied to the low temperature SCR denitration reaction of flue gas, is directly arranged behind a dust removing device even a desulfurizing device, can greatly reduce the operational temperature and operation cost of the traditional SCR process, and has high nitrogen oxide removing rate at the temperature of about 100 DEG C.

Description

technical field [0001] The invention relates to a catalyst, in particular to a honeycomb Mn-Ti-based catalyst used for low-temperature selective catalytic reduction denitrification reaction and a preparation and use method. Background technique [0002] NO emissions from stationary sources (coal-fired power plants, industrial boilers, etc.) X , to NH 3 Selective Catalytic Reduction (SCR) as a reducing agent is currently the most researched, most widely used, and most effective flue gas NO X removal technique. The most mature catalyst currently used is V 2 o 5 / TiO 2 or at V 2 o 5 / TiO 2 The main advantages of catalysts modified on the basis of carbon dioxide are high activity and high sulfur resistance, but such catalysts only have high activity when the operating temperature is higher than 350 ° C, so the SCR reactor can only be arranged in coal-saving Between the filter and the dust collector. However, most of the existing boilers do not reserve denitrification s...

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Problems solved by technology

In addition, although the low-temperature SCR system is placed after the desulfurization and / or dust removal equipment, the sulfur dioxide in the flue gas has not been completely removed, and the flue gas in this process section will still contain low concentrations of residual SO 2 , many research results show that in low temperature SCR reaction, SO 2 The existence of the catalyst will deactivate and greatly reduce the denitrification efficiency. Therefore, improving the sulfur resistance of the low-temperature SCR catalyst is the key to its industrial application.

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