Catalytic filter membrane and preparation method thereof

Abstract

The invention provides a catalytic filter membrane and a preparation method thereof. The catalytic filter membrane disclosed by the invention can be used for efficiently removing NOx (NO, NO2 and N2O) and dust in flue gas at the same time under a medium-temperature condition (150-400 DEG C). The catalytic filter membrane disclosed by the invention not only can remarkably reduce the occupied area of a pollutant treatment system, but also can reduce the operation cost, has a wide application field, and is suitable for various industrial flue gas emission scenes. In addition, the preparation process of the catalytic filter membrane is pollution-free, the preparation flow is simple to operate, the period is short, the related unit operation industrial basis is mature, large-scale production is easy to carry out, and the economic efficiency is good.

Description

Technical Field The present invention relates to a catalytic filter membrane and a preparation method thereof, and more specifically to a catalytic filter membrane for coordinated denitration and dust removal of medium-temperature flue gas and a preparation method thereof, belonging to the field of flue gas denitration and dust removal. Background Art In recent years, with the acceleration of industrialization and the continuous increase in energy demand, the problem of flue gas emissions has become increasingly serious, especially nitrogen oxides (NO x ) and dust, which poses a great threat to the environment and human health. Although traditional flue gas treatment technologies, such as SCR / SNCR denitrification and electric bag dust removal, can effectively reduce pollutant emissions to a certain extent, their treatment efficiency is limited by the fluctuation of flue gas temperature, and there are also problems such as large equipment footprint and high operating costs. Therefore, the existing flue gas treatment technology needs to be improved urgently. Summary of the invention Problem that the invention aims to solve In view of the above problems in current flue gas treatment, the present invention aims to provide a catalytic filter membrane and a preparation method thereof for achieving efficient synergistic denitrification and dust removal of flue gas under medium temperature conditions. The catalytic filter membrane of the present invention can denitrify NO in flue gas under medium temperature conditions (150-400°C). x The catalytic filter membrane of the present invention can not only significantly reduce the footprint of the pollutant treatment system, but also reduce the operating cost. It has a wide range of applications and is suitable for various industrial flue gas emission scenarios. Solutions for solving problems The inventors of the present invention have conducted in-depth research to solve the above problems. As a result, they found that the catalyst precursor is prepared by using active component metal salt, aluminum source compound and complexing agent as raw materials of catalyst precursor by sol-gel method, and introduced into the substrate by impregnation method, so as to obtain the NO in flue gas under medium temperature conditions. x Catalytic filter membrane that can remove air and dust simultaneously.

[0001] A method for preparing a catalytic filter membrane, the method comprising: Step A: mixing an active component metal salt, an aluminum source compound and a complexing agent and heating them to obtain a catalyst precursor; and Step B: Immersing a substrate in the catalyst precursor and drying it to obtain a catalytic filter membrane.

[0002] The preparation method according to [1], wherein the step A satisfies at least one of the following characteristics (a) to (l): (a) the active component in the active component metal salt includes at least one of manganese, iron, cerium, cobalt, nickel, copper, tin, lanthanum and zirconium; (b) the active component metal salt is a soluble metal salt of the active component; (c) the active component metal salt is at least one of acetate, nitrate and chloride of the active component; (d) the active component metal salt includes at least one of manganese acetate, manganese nitrate, manganese chloride, ferric nitrate, ferric acetate, ferric chloride, cerium nitrate, cerium chloride, cobalt nitrate, cobalt acetate, cobalt chloride, nickel nitrate, nickel acetate, nickel chloride, copper nitrate, copper acetate, copper chloride, tin tetrachloride, lanthanum nitrate and zirconium nitrate; (e) the aluminum source compound is an aluminum salt; (f) the aluminum source compound comprises aluminum nitrate, aluminum chloride or aluminum acetate; (g) the complexing agent includes at least one of a substance having one or more carboxyl groups, a substance having two or more amino groups, and a substance having two or more hydroxyl groups; (h) the complexing agent comprises citric acid; (i) the molar ratio of the active component metal salt to the aluminum source compound is 0.2:1 to 5:1; (j) the molar ratio of the active component metal salt to the complexing agent is 0.2:1 to 1:3; (k) the heating temperature is 50 to 95° C.; (l) Heating time is 2 to 5 hours.

[0003] The preparation method according to [1], wherein the step B satisfies at least one of the following characteristics (m) to (q): (m) placing the substrate into the catalyst precursor for impregnation at 110-130° C.; (n) The immersion time is 4 to 12 hours; (o) The substrate comprises a ceramic film, titanium oxide, aluminum oxide or silicon dioxide; (p) drying temperature is 100-130°C; (q) Drying time is 4 to 12 hours.

[0004] A catalytic filter membrane, wherein the catalytic filter membrane is obtained according to the preparation method described in any one of [1] to [3].

[0005] The catalytic filter membrane according to [4] is used for denitrification and dust removal at 150 to 400°C.

[0006] Application of the catalytic filter membrane according to [4] or [5] in ammonia selective catalytic reduction technology.

[0007] A method for treating waste gas, comprising: treating the waste gas using the catalytic filter membrane obtained according to the preparation method described in [1] to [3].

[0008] According to the treatment method described in [7], the waste gas includes at least one of the flue gas from thermal power plants, flue gas from industrial kilns, waste gas from cement manufacturing, waste incineration, waste gas from glass melting furnaces and waste gas from steel coke ovens. Effects of the Invention The main features and advantages of the present invention are as follows: (1) The raw materials used in the synthesis of the catalytic component precursor (such as manganese salts, aluminum salts and citric acid) are convenient and easy to obtain, the conditions are easy to control and not harsh, the production cycle is short, there is almost no pollution to the environment, and mass production can be achieved. (2) The preparation method of the catalytic filter membrane of the present invention is simple and the activity of the catalytic filter membrane is high. (3) The catalytic filter membrane of the present invention can still maintain a high denitration reaction activity at a relatively low temperature of 200° C., so that the catalytic filter membrane can be used at a lower flue gas temperature. (4) The present invention can achieve the coordinated removal of nitrogen oxides and dust from flue gas, simplify the flue gas pollutant control system, and reduce costs. The catalytic filter membrane of the present invention can reduce the NO in flue gas and waste gas that have an impact on the climate environment. x Successfully converted into N2, an inert gas that has no impact on the environment. The catalytic filter membrane of the present invention can be applied to flue gas treatment in the medium temperature zone. In addition, the preparation process of the catalytic filter membrane of the present invention is pollution-free, the preparation process is simple to operate, the cycle is short, the industrial basis of the unit operation involved is mature, and it is easy to carry out large-scale production with good economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 The test results of the catalytic membranes of Examples 1 and 2 in NH3-SCR (reaction temperature 200°C, reaction pressure normal pressure, NO and NH3 concentrations in the reaction gas are both 800 mg / m 3 , 6% O2, the rest N2, the reaction feed space velocity GHSV is 36000ml / g -1 / h -1 ). DETAILED DESCRIPTION Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments. In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention. Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production. In this specification, the word "may" means both performing a certain process and not performing a certain process. In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner. In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B. The preparation method of the catalytic filter membrane of the present invention comprises: Step A: mixing an active component metal salt, an aluminum source compound and a complexing agent and heating them to obtain a catalyst precursor; and Step B: Immersing a substrate in the catalyst precursor and drying it to obtain a catalytic filter membrane. The catalytic component of the catalytic filter membrane of the present invention is prepared by a sol-gel method as a precursor, and is introduced into a substrate (such as a ceramic membrane) by an impregnation method, and can catalyze NO in flue gas at medium temperature conditions (150-400°C). x The catalytic filter membrane of the present invention can not only significantly reduce the footprint of the pollutant treatment system, but also reduce the operating cost, and has a wide range of applications, and is suitable for various industrial flue gas emission scenarios. In addition, the preparation method of the catalytic filter membrane of the present invention is simple in process, the required raw materials are easily available, the environmental pollution is small, and it has low economic cost and good industrialization potential. This means that in large-scale applications, it can not only effectively reduce costs, but also reduce secondary pollution to the environment, which is in line with the concept of sustainable development. Process A As the active component in the active component metal salt, at least one of manganese, iron, cerium, cobalt, nickel, copper, tin, lanthanum and zirconium is preferably included, and manganese is more preferably included. In some preferred embodiments, the metal salt of the active ingredient is preferably a soluble metal salt of the active ingredient, more preferably at least one of acetate, nitrate and chloride salts of the active ingredient. In some preferred embodiments, the active component metal salt includes at least one of manganese acetate, manganese nitrate, manganese chloride, ferric nitrate, ferric acetate, ferric chloride, cerium nitrate, cerium chloride, cobalt nitrate, cobalt acetate, cobalt chloride, nickel nitrate, nickel acetate, nickel chloride, copper nitrate, copper acetate, copper chloride, tin tetrachloride, lanthanum nitrate and zirconium nitrate. The aluminum source compound is preferably an aluminum salt, more preferably a soluble aluminum salt. In some preferred embodiments, the aluminum source compound includes aluminum nitrate, aluminum chloride, or aluminum acetate. As the complexing agent, it is preferred to include at least one of substances having two or more carboxyl groups such as citric acid, oxalic acid, etc.; substances having one carboxyl group such as acetic acid, etc.; substances having two or more amino groups such as acetylacetonate, ethylenediamine, etc.; substances having two or more hydroxyl groups such as ethylene glycol, etc. In some preferred embodiments, the molar ratio of the active component metal salt to the aluminum source compound is preferably 0.2: 1 to 5: 1, more preferably 0.2: 1 to 4: 1. By setting the molar ratio of the active component metal salt to the aluminum source compound within the above range, the denitrification and dust removal effects can be better improved. In some specific embodiments, the molar ratio of the active component metal salt to the aluminum source compound is preferably 0.2:1, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 or 5:1. In some preferred embodiments, the molar ratio of the active component metal salt to the complexing agent is 0.2: 1 to 1: 3. By setting the molar ratio of the active component metal salt to the complexing agent within the above range, the denitrification and dust removal effects can be better improved. In some specific embodiments, the molar ratio of the active component metal salt to the complexing agent is 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1:1.5, 1:2, 1:2.5 or 1:3. In some preferred embodiments, the heating is preferably performed under stirring. There is no particular limitation on the stirring method, and for example, mechanical stirring or magnetic stirring may be used. In some preferred embodiments, the heating temperature is preferably 50 to 95° C., more preferably 50 to 80° C. By setting the heating temperature within the above range, the denitration and dust removal effects can be better improved. In some preferred embodiments, the heating temperature is preferably 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C. In some preferred embodiments, the heating time is preferably 2 to 5 hours, more preferably 2 to 4 hours. By setting the heating time within the above range, the denitrification and dust removal effects can be better improved. Process B In some preferred embodiments, the substrate is preferably immersed in the catalyst precursor at 110-130°C, more preferably at 110-120°C, so as to better obtain the NO in the flue gas under medium temperature conditions. x Catalytic filter membrane for simultaneous removal of particles and dust. In some preferred embodiments, the immersion time is preferably 4 to 12 hours, more preferably 6 to 10 hours. By setting the immersion time within the above range, it is possible to better obtain the NO in flue gas under medium temperature conditions. x Catalytic filter membrane for simultaneous removal of particles and dust. In some preferred embodiments, the substrate comprises a ceramic membrane, titanium oxide, aluminum oxide, or silicon dioxide. In some preferred embodiments, the drying temperature is preferably 100-130° C. By setting the drying temperature within the above range, it is possible to better obtain the NO in flue gas under medium temperature conditions. x Catalytic filter membrane for simultaneous removal of particles and dust. In some specific embodiments, the drying temperature is 100°C, 110°C, 120°C or 130°C. In some preferred embodiments, the drying time is preferably 4 to 12 hours. By setting the drying time within the above range, it is possible to better obtain the NO in flue gas under medium temperature conditions. x Catalytic filter membrane for simultaneous removal of particles and dust. In some specific embodiments, the drying time is 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 12 h. <Catalytic membrane> The present invention provides a catalytic filter membrane, which is a catalytic filter membrane obtained according to the preparation method of the present invention. The catalytic filter membrane of the present invention is a catalytic filter membrane formed by impregnating a catalyst component on a substrate. In some preferred embodiments, the catalyst component comprises the above-mentioned active component metal salt, aluminum source compound and complexing agent, and the substrate comprises a ceramic membrane, titanium oxide, aluminum oxide or silicon dioxide. The catalytic filter membrane of the present invention can adapt to the situation where the flue gas temperature is reduced due to flue gas peak regulation and load reduction, and maintain high denitrification activity. This is of great significance to the current industrial production process, because the flue gas temperature in industrial production often fluctuates due to load changes, and the efficiency of traditional flue gas treatment equipment tends to drop significantly in this case. In addition, the catalytic filter membrane of the present invention treats flue gas under medium temperature conditions (150-400°C), thus avoiding the problems of equipment wear and increased energy consumption that may occur during high or low temperature treatment. This not only prolongs the service life of the equipment, but also further reduces the operating cost and improves the overall economic benefits. At the same time, since the catalytic filter membrane of the present invention has high mechanical strength and excellent chemical stability, it can operate stably for a long time in harsh industrial environments, ensuring its wide application and reliability. The catalytic filter membrane of the present invention can achieve the removal of NO in flue gas under medium temperature conditions. x The efficient removal of waste gas and dust at the same time provides a new type of solution with broad application prospects for industrial flue gas treatment. Its high efficiency, economy and environmental protection are in line with the current development trend of flue gas pollutant treatment and have important practical application value and social significance. <Application of Catalytic Filter Membrane in Ammonia Selective Catalytic Reduction Technology (NH3-SCR)> The present invention also provides the use of the catalytic filter membrane obtained according to the preparation method of the present invention in ammonia selective catalytic reduction technology (NH3-SCR). In some preferred embodiments, the present invention also provides the use of the catalytic filter membrane obtained according to the preparation method of the present invention in the denitration of dust in medium-temperature flue gas. The present invention provides a method for treating waste gas, which comprises: treating the waste gas using a catalytic filter membrane obtained by the preparation method of the present invention. In some preferred embodiments, the above-mentioned waste gas includes flue gas from thermal power plants, flue gas from industrial kilns, waste gas from cement manufacturing, waste incineration, waste gas from glass melting furnaces, waste gas from steel coke ovens, etc. Example The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially. Example 1 (1) Mix 0.98 g manganese acetate, 1.0 g aluminum nitrate, and 1.4 g citric acid in 50 mL deionized water and stir continuously for 0.5 h to obtain Mn 1.2 Al 0.8 O3 mixed solution. (2) The obtained mixed solution was continuously stirred for 2.5 h under reflux heating at a heating temperature of 50° C. to obtain a mixed solution of catalytic components, which was then proportionally enlarged ten times. (3) Immerse the ceramic membrane in the solution obtained in step (2) above at 120°C for 6 hours, and then dry it overnight at 120°C to obtain Mn 1.2 Al 0.8 O3 based catalytic membrane. Example 2 A catalytic filter membrane was prepared in the same manner as in Example 1, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Mn 1.2 Al 0.8 O3 based catalytic membrane. Example 3 The catalytic membrane was prepared in the same manner as in Example 1 except that the amount of manganese acetate added in step (1) was changed to 1.3 g and the amount of aluminum nitrate added was changed to 0.5 g. 1.6 Al 0.4 O3 based catalytic membrane. Example 4 A catalytic filter membrane was prepared in the same manner as in Example 3, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Mn 1.6 Al 0.4 O3 based catalytic membrane. Example 5 The catalytic membrane was prepared in the same manner as in Example 1, except that the amount of manganese acetate added in step (1) was changed to 0.65 g and the amount of aluminum nitrate added was changed to 1.5 g. 0.8 Al 1.2 O3 based catalytic membrane. Example 6 A catalytic filter membrane was prepared in the same manner as in Example 5, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Mn 0.8 Al 1.2 O3 based catalytic membrane. Example 7 The catalytic membrane was prepared in the same manner as in Example 1 except that the amount of manganese acetate added in step (1) was changed to 0.33 g and the amount of aluminum nitrate added was changed to 2.0 g. 0.4 Al 1.6 O3 based catalytic membrane. Example 8 A catalytic filter membrane was prepared in the same manner as in Example 7, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Mn 0.4 Al 1.6 O3 based catalytic membrane. Example 9 (1) Mix 2.2 g of ferric nitrate, 0.5 g of aluminum nitrate, and 1.4 g of citric acid in 50 mL of deionized water and stir continuously for 0.5 h to obtain Fe 1.6 Al 0.4 O3 mixed solution. (2) The obtained mixed solution was continuously stirred for 2.5 h under reflux heating at a heating temperature of 50° C. to obtain a mixed solution of catalytic components, which was then proportionally enlarged ten times. (3) Immerse the ceramic membrane in the solution obtained in step (2) above at 120°C for 6 hours, and then dry it overnight at 120°C to obtain Fe 1.6 Al 0.4 O3 based catalytic membrane. Example 10 A catalytic filter membrane was prepared in the same manner as in Example 9, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Fe 1.6Al 0.4 O3 based catalytic membrane. Embodiment 11 The denitration catalytic filter membrane was prepared in the same manner as in Example 9, except that the amount of ferric nitrate added in step (1) was changed to 1.6 g and the amount of aluminum nitrate added was changed to 1.0 g. 1.2 Al 0.8 O3 based catalytic membrane. Example 12 A catalytic filter membrane was prepared in the same manner as in Example 11, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Fe 1.2 Al 0.8 O3 based catalytic membrane. Embodiment 13 The denitration catalytic filter membrane was prepared in the same manner as in Example 9, except that the amount of ferric nitrate added in step (1) was changed to 1.1 g and the amount of aluminum nitrate added was changed to 1.5 g. 0.8 Al 1.2 O3 based catalytic membrane. Embodiment 14 A catalytic filter membrane was prepared in the same manner as in Example 13, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Fe 0.8 Al 1.2 O3 based catalytic membrane. Embodiment 15 A denitration catalyst was prepared in the same manner as in Example 9 except that the amount of ferric nitrate added in step (1) was changed to 0.54 g and the amount of aluminum nitrate added was changed to 2.0 g. 0.4 Al 1.6 O3 catalyst. Example 16 A catalytic filter membrane was prepared in the same manner as in Example 15, except that step (3) was replaced by the following step (3). Step (3): The ceramic membrane was immersed in the solution obtained in the above step (2) at 120°C for 6 hours, and then dried overnight (drying temperature is 120°C). After drying overnight, the obtained membrane was placed in a muffle furnace and calcined at 200°C for 1 hour, and then heated at a heating rate of 10°C / min and calcined at 500°C for 2 hours to finally obtain Fe 0.4 Al 1.6 O3 based catalytic membrane. Comparative Example 1 The preparation process of the particle catalyst is as follows: NH4VO3, (NH4)6Mo7O 24 ·4H2O was uniformly mixed with industrial titanium dioxide and other metal salt precursors, and then deionized water was added and ball milled for 8 hours. The obtained sample was dried at 105°C for 5 hours, transferred to a muffle furnace and calcined at 450°C at a rate of 2°C / min for 5 hours. After cooling to room temperature, it was ground and sieved, and particles of 0.27-0.55 mm were taken for denitrification activity evaluation (particle catalyst V 10 Mo 10 、V 15 Mo 10 and V5Mo5). The granular catalyst was loaded on a blank filter bag by an impregnation method, the granular catalyst prepared by the above method, polytetrafluoroethylene (PTFE) and water were uniformly mixed by stirring to prepare a catalyst slurry (wherein PTFE was used as a binder during the impregnation process to firmly fix the catalyst particles on the filter bag), the blank filter bag was cut into a circle with a diameter of 15.5 cm, and then immersed in the prepared catalyst slurry for 10 minutes, and finally dried at 250°C for 2 hours to prepare a catalytic filter bag. The blank filter bag (from China Hongsheng Environmental Protection Technology Group Co., Ltd., woven from glass fibers with a diameter of 5 to 25 μm) was made of ammonium metavanadate (analytical grade), ammonium molybdate (analytical grade), titanium dioxide (industrial grade), polytetrafluoroethylene (PTFE) and deionized water. <Catalytic membrane evaluation method> In this article, the reaction volume space velocity is defined as the volume flow rate of the reaction gas raw material (base) entering the reaction system per hour divided by the mass of the catalyst, expressed as GHSV, in units of ml / g -1 / h -1 . Flue gas analyzer: Ecom J2KN Can measure NO, NO2, N2O, O2. Place the catalytic membranes in Examples 1 and 2 and Comparative Example 1 in the constant temperature zone of a fixed bed reactor. Adjust the temperature controller to 200°C, adjust the mass flow meter flow rate to 300mL / min (standard conditions), and the surface velocity to 0.5m / min. When the temperature stabilizes, start the reaction. The product is analyzed online, and samples are taken once per minute. The reaction temperature is 200°C, the reaction pressure is atmospheric pressure, and the molar composition of the raw gas is: the concentrations of NO and NH3 in the reaction gas are both 800mg / m 3 , 6% O2, the rest N2, the reaction feed space velocity GHSV is 36000ml / g -1 / h -1 . The NO conversion rate was calculated according to the following formula (1): Among them, NO in is the NO concentration at the inlet of the reaction tube, NO out is the NO concentration at the outlet of the reaction tube. The results of NO conversion of catalytic membrane at 200°C are shown in Figure 1 shown. Depend on Figure 1 It can be seen that in the NH3-SCR reaction process, the catalytic membranes of Examples 1 and 2 have high SCR activity at 200°C, the catalytic membrane of Example 1 can achieve a denitration activity of about 85%, and the catalytic membrane of Example 2 can achieve a denitration activity of about 49%. Moreover, as the reaction time increases, the catalytic membranes of Examples 1 and 2 can still maintain a high NO conversion rate, and the catalytic membrane of the present invention shows excellent reaction stability. In addition, the catalytic filter membranes of Examples 1 and 2 can achieve a dust removal effect of more than 99.5%. The catalytic filter membrane prepared by the preparation method of the present invention has good reaction stability and can adapt to harsh reaction environments. The catalytic filter membrane of the present invention can be used for NO in flue gas under medium temperature conditions. x And dust are removed efficiently at the same time. In Comparative Example 1, at 200° C. and a surface velocity of 0.5 m / min, the NO conversion rate of the catalytic filter membrane of Comparative Example 1 was about 26%, which was significantly lower than the denitration effects of Examples 1 and 2 of the present application. It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto. The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing a catalytic filter membrane, characterized in that: The preparation method comprises: Step A: mixing an active component metal salt, an aluminum source compound and a complexing agent and heating them to obtain a catalyst precursor; and Step B: Immersing a substrate in the catalyst precursor and drying it to obtain a catalytic filter membrane.

2. The preparation method according to claim 1, characterized in that: The process A satisfies at least one of the following characteristics (a) to (l): (a) the active component in the active component metal salt includes at least one of manganese, iron, cerium, cobalt, nickel, copper, tin, lanthanum and zirconium; (b) the active component metal salt is a soluble metal salt of the active component; (c) the active component metal salt is at least one of acetate, nitrate and chloride of the active component; (d) the active component metal salt includes at least one of manganese acetate, manganese nitrate, manganese chloride, ferric nitrate, ferric acetate, ferric chloride, cerium nitrate, cerium chloride, cobalt nitrate, cobalt acetate, cobalt chloride, nickel nitrate, nickel acetate, nickel chloride, copper nitrate, copper acetate, copper chloride, tin tetrachloride, lanthanum nitrate and zirconium nitrate; (e) the aluminum source compound is an aluminum salt; (f) the aluminum source compound comprises aluminum nitrate, aluminum chloride or aluminum acetate; (g) the complexing agent includes at least one of a substance having one or more carboxyl groups, a substance having two or more amino groups, and a substance having two or more hydroxyl groups; (h) the complexing agent comprises citric acid; (i) the molar ratio of the active component metal salt to the aluminum source compound is 0.2:1 to 5:1; (j) the molar ratio of the active component metal salt to the complexing agent is 0.2:1 to 1:3; (k) the heating temperature is 50 to 95° C.; (l) Heating time is 2 to 5 hours.

3. The preparation method according to claim 1, characterized in that: The process B satisfies at least one of the following characteristics (m) to (q): (m) placing the substrate into the catalyst precursor for impregnation at 110-130° C.; (n) Immersion time is 4 to 12 hours; (o) The substrate comprises a ceramic film, titanium oxide, aluminum oxide or silicon dioxide; (p) drying temperature is 100-130°C; (q) Drying time is 4 to 12 hours.

4. A catalytic filter membrane, characterized in that: The catalytic filter membrane is obtained according to the preparation method described in any one of claims 1 to 3.

5. The catalytic filter membrane according to claim 4, characterized in that: It is used for denitrification and dust removal at 150-400°C.

6. Use of the catalytic filter membrane according to claim 4 or 5 in ammonia selective catalytic reduction technology.

7. A method for treating waste gas, characterized in that: It includes: The waste gas is treated using the catalytic filter membrane obtained by the preparation method according to claims 1 to 3.

8. The processing method according to claim 7, characterized in that: The waste gas includes at least one of the flue gas from thermal power plants, the flue gas from industrial kilns, the waste gas from cement manufacturing, the waste gas from garbage incineration, the waste gas from glass melting furnaces and the waste gas from steel coke ovens.

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