阅读说明：本技术 一种燃气脱硝用小孔径波纹式催化剂及其制备方法 (Small-aperture corrugated catalyst for gas denitration and preparation method thereof ) 是由 肖雷 刘炜 蒋宗安 姚元庆 杨莎莎 冯艳婷 曹朋辉 于 2019-12-06 设计创作，主要内容包括：本发明属于烟气脱硝技术领域,涉及燃气脱硝用小孔径波纹式催化剂及其制备方法,该催化剂包括以下原料：以玻璃纤维薄毡为骨架基材,以硫酸氧钛、氧化硅中的一种或者两种为载体,以七钼酸铵、铈盐中的一种或者两种为助剂,以锰盐、铁盐、铬盐中的一种或者多种为活性组分前驱体及去离子水；所述载体为90份,活性组分前驱体为1.6-6.5份,助剂为3.8-5.1份,去离子水为120-200份。该催化剂,以硫酸氧钛、氧化硅为载体,保证催化剂在高温时有良好的热稳定性,不会发生晶型变化和烧结；以锰盐、铁盐、铬盐为活性组分,可避免因溶液粘度大而发生堵孔的情况发生,以七钼酸铵、铈盐为改性助剂,在SCR反应中具备极强的催化性能。(The invention belongs to the technical field of flue gas denitration, and relates to a small-aperture corrugated catalyst for gas denitration and a preparation method thereof, wherein the catalyst comprises the following raw materials: the preparation method comprises the following steps of (1) taking a glass fiber mat as a framework substrate, one or two of titanyl sulfate and silicon oxide as a carrier, one or two of ammonium heptamolybdate and cerium salt as an auxiliary agent, one or more of manganese salt, ferric salt and chromium salt as an active component precursor and deionized water; 90 parts of carrier, 1.6-6.5 parts of active component precursor, 3.8-5.1 parts of auxiliary agent and 200 parts of deionized water. The catalyst takes titanyl sulfate and silicon oxide as carriers, so that the catalyst has good thermal stability at high temperature and can not generate crystal form change and sintering; the manganese salt, the ferric salt and the chromium salt are used as active components, so that the phenomenon of hole blocking caused by high solution viscosity can be avoided, and the ammonium heptamolybdate and the cerium salt are used as modification aids and have extremely strong catalytic performance in SCR reaction.)

1. The small-aperture corrugated catalyst for gas denitration is characterized by comprising the following raw materials: the preparation method comprises the following steps of (1) taking a glass fiber mat as a framework substrate, one or two of titanyl sulfate and silicon oxide as a carrier, one or two of ammonium heptamolybdate and cerium salt as an auxiliary agent, one or more of manganese salt, ferric salt and chromium salt as an active component precursor and deionized water; 90 parts of carrier, 1.6-6.5 parts of active component precursor, 3.8-5.1 parts of auxiliary agent and 200 parts of deionized water.

2. The small-pore-diameter corrugated catalyst for denitration of a fuel gas according to claim 1, wherein the mass of the glass fiber mat is 20 g.

3. The small-pore-diameter corrugated catalyst for denitration of a fuel gas according to claim 1, wherein the thickness of the inner wall of the corrugated catalyst is 0.3 ± 0.05 mm.

4. The small-aperture corrugated catalyst for gas denitration according to claim 1, wherein the aperture of the corrugated catalyst is 1.6-2.0mm, and the wavelength is 3.6 mm.

5. The small-pore-diameter corrugated catalyst for gas denitration according to claim 1, wherein the number of pores of the corrugated catalyst is 75.

6. The small-pore-diameter corrugated catalyst for denitration of a fuel gas as claimed in claim 1, wherein the specific surface area of the corrugated catalyst is 1550m²/m³The porosity was 76.6%.

7. A preparation method of a small-aperture corrugated catalyst for gas denitration is characterized by comprising the following steps:

1) selecting a glass fiber thin felt as a framework material, manufacturing corrugated plates by adopting a forming liquid and a forming process, and stacking the corrugated plates and flat plates into units;

2) dipping the unit prepared in the step 1) in a mixed solution containing active ingredients of the catalyst, preparing the mixed solution according to a proportion, stirring for more than 30min, pouring the mixed solution into a dipping pool, carrying out negative pressure dipping on the units one by one, and airing the units on a platform for more than 2h after dipping is finished; wherein the preparation proportion of the mixed solution is as follows: 90 parts of carrier, 1.6-6.5 parts of active component precursor, 3.8-5.1 parts of auxiliary agent and 120-200 parts of deionized water, and then 0.7-1.1 parts of sulfuric acid is added to adjust the pH value; the carrier comprises one or two of titanyl sulfate and silicon oxide; the auxiliary agent comprises one or two of ammonium heptamolybdate and cerium salt; the active component precursor comprises one or more of manganese salt, ferric salt and chromium salt;

3) and (3) calcining the impregnated unit in the step 2) in a sintering furnace for 6 hours to finish the preparation of the whole corrugated catalyst.

8. The preparation method of the small-aperture corrugated catalyst for denitration of fuel gas according to claim 7, wherein the step 1) specifically comprises:

1.1) preparing a forming liquid according to the following proportion: the forming liquid is a mixed liquid composed of 30-50% of methanol, 30-40% of silica sol and 10-40% of water by mass percentage;

1.2) setting the temperature of a drying furnace and a forming roller of a forming machine, and feeding when the temperature reaches a set value, wherein the set temperature is 120-180 ℃ of the drying furnace, 200-240 ℃ of the forming upper roller and 90-120 ℃ of the forming lower roller;

1.3) soaking a glass fiber felt sample in a forming liquid, feeding the sample into a forming counter-pressure roller after passing through a drying furnace, and heating the sample at a high temperature to form a corrugated plate A;

1.4) cutting the corrugated plate A in the step 1.3) into a plurality of corrugated plates B with specified lengths by using a cutting machine, and cutting flat plates with the same size for unit assembly.

9. The method for preparing the small-aperture corrugated catalyst for denitration of fuel gas according to claim 7, wherein the calcining of the sintering furnace in the step 3) specifically comprises:

3.1) drying: the drying condition is that the temperature in the sintering furnace is increased to 240 ℃ from the ambient temperature, and the time is 80-120 min;

3.2) calcining: the calcination condition is that the temperature in the sintering furnace is increased from 240 ℃ to 250 ℃, the time is consumed for 30min, and the temperature is kept for 30min at 250 ℃; controlling the temperature in the sintering furnace to rise by 50 ℃ every time, consuming 30min, and keeping the temperature at the current temperature for 30min until the temperature rises to 350 ℃.

Technical Field

The invention belongs to the technical field of flue gas denitration, relates to a denitration catalyst, and particularly relates to a small-aperture corrugated catalyst for gas denitration and a preparation method thereof.

Background

At present, the flue gas discharged by a boiler taking natural gas as fuel has the characteristics of high temperature, low sulfur content and almost no dust. Compared with a coal-fired boiler, the gas-fired boiler has the advantages of high combustion efficiency, low pollutant emission concentration and the like. However, gas boilers also produce small amounts of nitrogen oxides during combustion. Along with the stricter air pollution control policy, besides the denitration measures of the combustion process such as staged combustion, fuel reburning and the like, the standard emission can be realized only after the denitration of flue gas such as SCR and the like is adopted.

The domestic and foreign SCR denitration is widely applied to coal-fired units due to mature technology, and the denitration catalyst applied to the domestic traditional coal-fired power plant is mainly V-WO₃/TiO₂The catalyst has high dust content, the aperture is between 5.8 and 9.5mm, and the number of holes is between 12 and 25, but the catalyst is not applied to a gas turbine set. Because the small-aperture catalyst has more wall thin holes, the traditional honeycomb catalyst is difficult to extrude and form, the rate of finished products is low, the consumption of carriers, active components and auxiliaries is large, the specific surface area of the finished product is low, the weight is heavy, the load requirement of an SCR system is increased, and the whole construction cost is increased; in addition, the denitration catalyst finished product powder is loaded in a coating or direct impregnation mode, the mixed solution has poor fluidity, and hole plugging is easy to occur in the production of producing small-aperture catalysts, so that the pressure drop of the products in use is large, and the service performance of the products is influenced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a small-aperture corrugated catalyst for gas denitration and a preparation method thereof.

In order to achieve the purpose, the invention provides the following technical scheme:

on one hand, the invention provides a small-aperture corrugated catalyst for gas denitration, which comprises the following raw materials: the preparation method comprises the following steps of (1) taking a glass fiber mat as a framework substrate, one or two of titanyl sulfate and silicon oxide as a carrier, one or two of ammonium heptamolybdate and cerium salt as an auxiliary agent, one or more of manganese salt, ferric salt and chromium salt as an active component precursor and deionized water; 90 parts of carrier, 1.6-6.5 parts of active component precursor, 3.8-5.1 parts of auxiliary agent and 200 parts of deionized water.

Further, the glass fiber mat had a mass of 20 g.

Further, the thickness of the inner wall of the corrugated catalyst is 0.3 +/-0.05 mm.

Furthermore, the aperture of the corrugated catalyst is 1.6-2.0mm, and the wavelength is 3.6 mm.

Further, the number of pores of the corrugated catalyst was 75 pores.

Further, the specific surface area of the corrugated catalyst is 1550m²/m³The porosity was 76.6%.

On the other hand, the invention also provides a preparation method of the small-aperture corrugated catalyst for gas denitration, which comprises the following steps:

1) selecting a glass fiber thin felt as a framework material, manufacturing corrugated plates by adopting a forming liquid and a forming process, and stacking the corrugated plates and flat plates into units;

2) dipping the unit prepared in the step 1) in a mixed solution containing active ingredients of the catalyst, preparing the mixed solution according to a proportion, stirring for more than 30min, pouring the mixed solution into a dipping pool, carrying out negative pressure dipping on the units one by one, and airing the units on a platform for more than 2h after dipping is finished; wherein the preparation proportion of the mixed solution is as follows: 90 parts of carrier, 1.6-6.5 parts of active component precursor, 3.8-5.1 parts of auxiliary agent and 120-200 parts of deionized water, and then 0.7-1.1 parts of sulfuric acid is added to adjust the pH value; the carrier comprises one or two of titanyl sulfate and silicon oxide; the auxiliary agent comprises one or two of ammonium heptamolybdate and cerium salt; the active component precursor comprises one or more of manganese salt, ferric salt and chromium salt;

3) and (3) calcining the impregnated unit in the step 2) in a sintering furnace for 6 hours to finish the preparation of the whole corrugated catalyst.

Further, the step 1) specifically comprises:

1.1) preparing a forming liquid according to the following proportion: the forming liquid is a mixed liquid composed of 30-50% of methanol, 30-40% of silica sol and 10-40% of water by mass percentage;

1.2) setting the temperature of a drying furnace and a forming roller of a forming machine, and feeding when the temperature reaches a set value, wherein the set temperature is 120-180 ℃ of the drying furnace, 200-240 ℃ of the forming upper roller and 90-120 ℃ of the forming lower roller;

1.3) soaking a glass fiber felt sample in a forming liquid, feeding the sample into a forming counter-pressure roller after passing through a drying furnace, and heating the sample at a high temperature to form a corrugated plate A;

1.4) cutting the corrugated plate A in the step 1.3) into a plurality of corrugated plates B with specified lengths by using a cutting machine, and cutting flat plates with the same size for unit assembly.

Further, the calcining of the sintering furnace in the step 3) specifically includes:

3.1) drying: the drying condition is that the temperature in the sintering furnace is increased to 240 ℃ from the ambient temperature, and the time is 80-120 min;

3.2) calcining: the calcination condition is that the temperature in the sintering furnace is increased from 240 ℃ to 250 ℃, the time is consumed for 30min, and the temperature is kept for 30min at 250 ℃; controlling the temperature in the sintering furnace to rise by 50 ℃ every time, consuming 30min, and keeping the temperature at the current temperature for 30min until the temperature rises to 350 ℃.

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects: titanyl sulfate and silicon oxide are used as carriers, so that the catalyst has good thermal stability at high temperature, and crystal form change and sintering are avoided; manganese salt, ferric salt and chromium salt are used as active components, a precursor salt formula is selected to avoid the occurrence of hole blocking caused by high solution viscosity, ammonium heptamolybdate and cerium salt are used as modification aids, the catalyst has extremely strong catalytic performance in SCR reaction, and proper amount of cerium is added to enhance the thermal stability of the catalyst and prolong the service life of the catalyst.

In addition, the aperture of the small-aperture corrugated catalyst provided by the invention is 1.6-2.0mm, the wavelength is 3.6mm, the number of the holes is 75, the number of the holes is smaller than that of the existing vanadium denitration catalyst, the number of the holes is more, and the volume consumption is small under the same condition. The small-aperture corrugated catalyst has the advantages of large specific surface area, light weight, high porosity and the like, is increased by 339.9 percent compared with the common coal-fired corrugated catalyst, is increased by 24.76 percent compared with the geometric specific surface area of the traditional specification honeycomb denitration catalyst, is increased by 17.95 percent in porosity, and is 50-100kg lower in weight per cubic meter compared with the traditional honeycomb catalyst.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic diagram showing the specification of a small-pore-diameter corrugated catalyst for denitration of fuel gas according to the present invention.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of products and methods consistent with certain aspects of the invention, as detailed in the appended claims.

In order to make those skilled in the art better understand the technical solution of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings and examples.