CN-121972155-A - Wide-temperature denitration catalyst and preparation method thereof

CN121972155ACN 121972155 ACN121972155 ACN 121972155ACN-121972155-A

Abstract

The invention relates to the technical field of high-efficiency catalysts and prevention and control of atmospheric pollutants, in particular to a wide-temperature denitration catalyst and a preparation method thereof. The preparation method comprises the steps of adding deionized water and a dispersing agent into a reaction kettle, heating and stirring, then simultaneously injecting a salt solution and a precipitant solution into the reaction kettle, continuously stirring the mixed solution after feeding, filtering, washing and drying after ageing to obtain precursor powder, calcining the precursor powder under the atmosphere of N 2 to obtain calcined powder, placing the calcined powder into a mixed aqueous solution of ammonium metavanadate and ammonium heptamolybdate, stirring in a water bath for reaction, drying, and calcining to obtain the wide-temperature denitration catalyst. The invention realizes the wide temperature characteristic of low-temperature high-efficiency denitration and high-temperature stable denitration of the catalyst by the active component dispersion, the layered structure regulation and control and the cooperative construction of high-temperature active sites and low-temperature active sites, and effectively adapts to the working condition characteristics of great fluctuation of the industrial flue gas temperature.

Inventors

LI JINKE
HU QINGYUAN
CHI YUCHEN
HUANG LI
YUE YANWEI
WANG HU
ZONG YUHAO
XIE XINGXING
WANG QUANHUA
GUO LIXING
LIU KAIMING

Assignees

大唐南京环保科技有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260105

Claims (10)

1. The preparation method of the wide-temperature denitration catalyst is characterized by comprising the following steps of: S1, adding deionized water and a dispersing agent into a reaction kettle, heating, stirring, simultaneously injecting a salt solution and a precipitant solution into the reaction kettle, continuously stirring the mixed solution after feeding, aging, filtering, washing and drying to obtain precursor powder; s2, calcining the precursor powder in an atmosphere of N 2 to obtain calcined powder; s3, placing the calcined powder into a mixed aqueous solution of ammonium metavanadate and ammonium heptamolybdate, stirring in a water bath, reacting, drying, and calcining to obtain the wide-temperature denitration catalyst.
2. The preparation method of the wide-temperature denitration catalyst according to claim 1, wherein in the step S1, the dispersing agent adopts one of polyethylene glycol, span and tween, and the mass of the dispersing agent is 0.5-2 wt% of deionized water.
3. The method for preparing a wide temperature range denitration catalyst according to claim 1, wherein the salt solution is a mixed solution of copper nitrate, manganese nitrate and aluminum nitrate.
4. The method for preparing a wide temperature range denitration catalyst according to claim 1, wherein the precipitant is one of sodium carbonate and potassium carbonate.
5. The method for preparing a wide temperature range denitration catalyst according to claim 1, wherein the pH value of the mixed solution in step S1 is 9 to 12.
6. The preparation method of the wide-temperature denitration catalyst according to claim 1, wherein the specific step of the step S1 is characterized in that deionized water and a dispersing agent are added into a reaction kettle, the reaction kettle is heated to 60-90 ℃, stirring is started, then a salt solution and a precipitant solution are simultaneously injected into the reaction kettle, the pH value of the mixed solution is regulated, the mixed solution is continuously stirred after the addition, and after aging for 2-18 hours, the precursor powder is obtained through filtering, washing and drying.
7. The preparation method of the wide-temperature range denitration catalyst according to claim 1, wherein the specific step of the step S2 comprises the step of calcining precursor powder at the temperature of 250-400 ℃ in the atmosphere of N 2 for 0.5-2 hours to obtain calcined powder.
8. The preparation method of the wide-temperature denitration catalyst according to claim 1, wherein the specific step of the step S3 comprises the steps of placing calcined powder into a mixed aqueous solution of ammonium metavanadate and ammonium heptamolybdate, stirring for 2-4 hours in a water bath at 60-90 ℃, drying, and calcining for 1-2 hours at 300-400 ℃ in an atmosphere of 5-10 vol% O 2 /N 2 to obtain the wide-temperature denitration catalyst.
9. The wide-temperature denitration catalyst is characterized by being prepared by adopting the preparation method of the wide-temperature denitration catalyst as claimed in any one of claims 1 to 8.
10. The wide temperature range denitration catalyst according to claim 9, wherein the mass fraction of CuO in the wide temperature range denitration catalyst is 30-40 wt%, the mass fraction of MnO 2 is 20-30 wt%, the mass fraction of Al 2 O 3 is 15-30 wt%, the mass fraction of V 2 O 5 is 5-10 wt%, and the mass fraction of MoO 3 is 5-10 wt%.

Description

Wide-temperature denitration catalyst and preparation method thereof Technical Field The invention relates to the technical field of high-efficiency catalysts and prevention and control of atmospheric pollutants, in particular to a wide-temperature denitration catalyst and a preparation method thereof. Background Nitrogen oxide (NO X) is used as a main atmospheric pollutant discharged in the industrial fields of thermal power, steel, coking and the like, not only forms a core cause of acid rain and photochemical smog, but also can cause serious harm to human respiratory systems, and the discharge control of the nitrogen oxide is a key task of atmospheric pollution control in China. The Selective Catalytic Reduction (SCR) technology is a main stream technology for treating the NO X of the current industrial flue gas because of high denitration efficiency and good operation stability, and the performance of the catalyst serving as the core of the SCR technology directly determines the denitration effect and the operation cost. The industrial flue gas working conditions are complex and changeable, the flue gas temperature difference of different industries and different production links in the same industry is obvious, for example, the tail flue gas temperature of a thermal power boiler is 300-400 ℃ generally, the flue gas temperature of a steel sintering machine fluctuates more than 180-350 ℃, and the flue gas temperature of waste incineration can change in the range of 200-450 ℃. This characteristic places a central need for "wide temperature window activity" for SCR catalysts. Therefore, the catalyst is required to have high denitration efficiency, good thermal stability and poisoning resistance in a wide temperature range. Disclosure of Invention A first object of the present invention is to provide a wide temperature range denitration catalyst that can solve the above-described technical problems. The second aim of the invention is to provide a preparation method of the wide-temperature denitration catalyst. The invention provides a preparation method of a wide-temperature denitration catalyst, which comprises the following steps: S1, adding deionized water and a dispersing agent into a reaction kettle, heating, stirring, simultaneously injecting a salt solution and a precipitant solution into the reaction kettle, continuously stirring the mixed solution after feeding, aging, filtering, washing and drying to obtain precursor powder; s2, calcining the precursor powder in an atmosphere of N 2 to obtain calcined powder; s3, placing the calcined powder into a mixed aqueous solution of ammonium metavanadate and ammonium heptamolybdate, stirring in a water bath, reacting, drying, and calcining to obtain the wide-temperature denitration catalyst. Preferably, in the step S1, the dispersing agent adopts one of polyethylene glycol, span and tween, and the mass of the dispersing agent is 0.5-2 wt% of deionized water. Preferably, the salt solution is a mixed solution of copper nitrate, manganese nitrate and aluminum nitrate. Preferably, the precipitant is one of sodium carbonate and potassium carbonate. Preferably, the pH value of the mixed solution in the step S1 is 9-12. Preferably, the specific step of the step S1 comprises the steps of adding deionized water and a dispersing agent into a reaction kettle, heating to 60-90 ℃, starting stirring, then simultaneously injecting a salt solution and a precipitant solution into the reaction kettle, adjusting the pH value of the mixed solution, continuously stirring the mixed solution after feeding, aging for 2-18 hours, and then filtering, washing and drying to obtain precursor powder. Preferably, the volume of deionized water is 10-30% of the total volume of the salt solution and the precipitant solution. Preferably, the specific step of the step S2 comprises the step of calcining the precursor powder for 0.5-2 hours at the temperature of 250-400 ℃ in the atmosphere of N 2 to obtain calcined powder. Preferably, the specific step of the step S3 comprises the steps of placing the calcined powder in a mixed aqueous solution of ammonium metavanadate and ammonium heptamolybdate, stirring for 2-4 hours in a water bath at 60-90 ℃, drying, and calcining for 1-2 hours at 300-400 ℃ in an O 2/N2 -10 vol% atmosphere to obtain the wide-temperature denitration catalyst. The invention also provides a wide-temperature denitration catalyst, which is prepared by adopting the preparation method of the wide-temperature denitration catalyst. Preferably, the mass fraction of CuO in the wide-temperature denitration catalyst is 30-40 wt%, the mass fraction of MnO 2 is 20-30 wt%, the mass fraction of Al 2O3 is 15-30 wt%, the mass fraction of V 2O5 is 5-10 wt%, and the mass fraction of MoO 3 is 5-10 wt%. Based on the target mass fraction of each component in the wide-temperature denitration catalyst product, the stoichiometric relation among the salt solution, the precipitator, the ammonium metav