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CN-121972180-A - High-sulfur-resistance water-resistance denitration catalyst and preparation method thereof

CN121972180ACN 121972180 ACN121972180 ACN 121972180ACN-121972180-A

Abstract

The invention discloses a high sulfur-resistant water-resistant denitration catalyst and a preparation method thereof, the catalyst comprises a modified carrier and an active component loaded on the modified carrier, the modified carrier comprises fly ash, titanium dioxide and iron powder, and the active components comprise oxides of vanadium and tungsten. According to the invention, the iron modified fly ash is used for partially replacing titanium dioxide as a carrier of the catalyst, vanadium and tungsten active components are loaded, and the obtained denitration catalyst has excellent sulfur and water resistance, and also has a wide active temperature window and high nitrogen selectivity, and the preparation process is simple, easy to operate, low in cost and high in environmental value and economic value.

Inventors

  • JIANG XIAORAN
  • NIU YONGJUN
  • AN ZHEN
  • YAO HAO
  • ZHOU MENGWEI
  • WANG ZEXUAN
  • MA BAOLIN
  • GUAN JIAN
  • LU GANG
  • WU WEI
  • FAN JIANG
  • CHANG LEI
  • LEI MING
  • NIU GUOPING

Assignees

  • 华能国际电力股份有限公司大连电厂
  • 西安西热锅炉环保工程有限公司

Dates

Publication Date
20260505
Application Date
20260206

Claims (10)

  1. 1. The catalyst is characterized by comprising a modified carrier and an active component loaded on the modified carrier, wherein the modified carrier comprises fly ash, titanium dioxide and iron powder, and the active component comprises oxides of vanadium and tungsten.
  2. 2. The high sulfur-resistant water-resistant denitration catalyst according to claim 1, wherein the mass of the modified carrier accounts for 95.2-98.5% of the total mass of the catalyst, wherein the fly ash accounts for 30-66% of the total mass of the catalyst, the titanium pigment accounts for 29-65% of the total mass of the catalyst, and the iron powder accounts for 0.5-7.0% of the total mass of the catalyst.
  3. 3. The high sulfur-resistant water-resistant denitration catalyst according to claim 1, wherein the mass of the active component accounts for 1.5-4.8% of the total mass of the catalyst, wherein the oxide of vanadium accounts for 0.7-2.0% of the total mass of the catalyst, and the oxide of tungsten accounts for 0.8-3.2% of the total mass of the catalyst.
  4. 4. The high sulfur and water resistant denitration catalyst as claimed in claim 1 or 2, wherein the modified carrier is prepared by a method comprising the following steps: step a, mixing fly ash with acetic acid solution, and performing wet ball milling to obtain acid-treated fly ash; step b, washing, drying and sieving the fly ash subjected to the acid treatment to obtain pretreated fly ash; and c, mixing the pretreated fly ash with iron powder and titanium dioxide, and performing dry ball milling to obtain the modified carrier.
  5. 5. The high sulfur-resistant water-resistant denitration catalyst according to claim 4, wherein in the step a, the concentration of the acetic acid solution is 0.5-2 mol/L; And/or the rotating speed of the wet ball milling is 140-200 r/min, and the ball milling time is 2-5 h.
  6. 6. The high sulfur-resistant water-resistant denitration catalyst according to claim 4, wherein in the step b, the drying temperature is 100-120 ℃ and the drying time is 3-8 hours; and/or the mesh number of the screen mesh adopted by the sieving is 80-120 meshes.
  7. 7. The high sulfur-resistant water-resistant denitration catalyst according to claim 4, wherein in the step c, the rotation speed of the dry ball milling is 120-200 r/min, and the ball milling time is 2-5 h.
  8. 8. A method for preparing the high sulfur-resistant water-resistant denitration catalyst as claimed in any one of claims 1 to 7, which comprises the following steps: (1) Placing ammonium metatungstate, ammonium metavanadate and anhydrous oxalic acid in water, stirring and dissolving to obtain an active component solution; (2) Immersing the modified carrier into the active component solution, uniformly stirring, standing, and naturally airing; (3) And (3) calcining the sample dried in the step (2) to obtain the high-sulfur-resistance water-resistance denitration catalyst.
  9. 9. The method for preparing the high sulfur-resistant water-resistant denitration catalyst according to claim 8, wherein in the step (2), the standing time is 1-2 hours.
  10. 10. The method for preparing the high sulfur-resistant water-resistant denitration catalyst according to claim 8, wherein in the step (3), the temperature rising rate of the calcination treatment is 3-7 ℃ per minute, the calcination temperature is 500-550 ℃, and the calcination time is 1.5-5 h.

Description

High-sulfur-resistance water-resistance denitration catalyst and preparation method thereof Technical Field The invention belongs to the technical field of industrial flue gas purification treatment, and particularly relates to a high-sulfur-resistance water-resistance denitration catalyst and a preparation method thereof. Background Coal-fired thermal power plants are a main source of power supply in China, however, nitrogen oxides (NO X) in coal-fired flue gas have great harm to human bodies and the environment. If NO X is directly discharged into the atmosphere, it will not only react with water vapor in the air to generate nitric acid and nitrous acid, resulting in the formation of acid rain, but also combine with hydrocarbons in the atmosphere to form photochemical smog, which poses a serious threat to the quality of soil, water sources, plants and urban air, and further worsen the quality of air by forming atmospheric particulates. In addition, NO X stimulates the respiratory tract to cause respiratory diseases and influence the health of the cardiovascular system, and NO X may damage the nervous system and influence the daily life quality and long-term health of people. Therefore, the treatment of NO X in the atmosphere is particularly important. The ammonia selective catalytic reduction (NH 3 -SCR) technology is one of the most widely used flue gas denitration technologies at present, and uses ammonia as a reducing agent to selectively reduce NO X by a catalyst to generate nitrogen and water. Among them, the vanadium-based catalysts (V 2O5-WO3/TiO2, VWTi) are widely used in industry due to their excellent activity and stability. The VWTi catalyst is obtained by taking titanium dioxide (TiO 2) as a carrier and loading active components V 2O5 and WO 3, wherein the carrier titanium dioxide accounts for 94-97wt%. However, with the increasing price of titanium dioxide, challenges are presented to the cost control of the catalyst. In addition, the commercial VWTi catalyst has a higher operating temperature window (typically 300-400 ℃), the SCR arrangement is required to be a high-dust arrangement, and the disadvantage of the arrangement is that high concentration of sulfur (SO 2) and water (H 2 O) in the flue gas can cause poisoning and deactivation of the catalyst, SO that further reduction of the cost of the commercial VWTi catalyst and improvement of the sulfur and water resistance are important directions of current researches. Fly Ash (CFA) is waste generated by coal-fired power plants, has low recycling rate, and needs to develop new utilization ways. At present, some researches on preparing a denitration catalyst by using fly ash exist, the method for synthesizing a zeolite molecular sieve by using the fly ash and then loading active components adopts the most means, but the path involves complicated Si/Al ratio regulation and control, acid-base high-temperature activation, hydrothermal treatment and subsequent purification steps, so that the operation is complicated, the yield is limited, and meanwhile, the use of strong acid and strong alkali also forms a potential threat to the environment. Therefore, how to effectively combine fly ash, a waste, with a denitration catalyst has become a focus of attention. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the embodiment of the invention provides a high sulfur-resistant water-resistant denitration catalyst and a preparation method thereof. The denitration catalyst has excellent sulfur and water resistance, wide active temperature window, high nitrogen selectivity and low cost. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, an embodiment of the invention provides a high sulfur-resistant and water-resistant denitration catalyst, which comprises a modified carrier and an active component loaded on the modified carrier, wherein the modified carrier comprises fly ash, titanium dioxide and iron powder, and the active component comprises oxides of vanadium and tungsten. In some embodiments, the mass of the modified carrier accounts for 95.2-98.5% of the total mass of the catalyst, wherein the fly ash accounts for 30-66% of the total mass of the catalyst, the titanium dioxide accounts for 29-65% of the total mass of the catalyst, and the iron powder accounts for 0.5-7.0% of the total mass of the catalyst. In some embodiments, the active component accounts for 1.5-4.8% of the total mass of the catalyst, wherein the oxide of vanadium accounts for 0.7-1.6% of the total mass of the catalyst, and the oxide of tungsten accounts for 0.8-3.2% of the total mass of the catalyst. In some embodiments, the modified support is prepared by a process comprising the steps of: step a, mixing fly ash with acetic acid solution, and performing wet ball milling to obtain acid-treated fly ash; step b, washing, dryi