KR102195343B1 - Method of Preparing Catalyst for Removing Nitrogen Oxides Using Waste FCC Catalysts - Google Patents

Abstract

The present invention relates to a method of manufacturing a catalyst for removing nitrogen oxides using a waste catalyst in the FCC process, and more particularly, anatase-type titanium dioxide, vanadium, and antimony are mixed at a specific mixing ratio using the waste catalyst discharged from the FCC process as a main material. , By using the foundry dust as a binder to produce a denitration catalyst, it has excellent price competitiveness compared to the conventional catalyst for removing nitrogen oxides, and at the same time, it is possible to use the waste catalyst discharged from the FCC process and the foundry dust, which is a waste generated in the foundry, with high added value. , It relates to a method for producing a catalyst for removing nitrogen oxides using a waste FCC process catalyst that can easily produce a catalyst for removing nitrogen oxides excellent in performance and durability with a simple manufacturing process.

Description

[Method of Preparing Catalyst for Removing Nitrogen Oxides Using Waste FCC Catalysts]

The present invention relates to a method of manufacturing a catalyst for removing nitrogen oxides using a waste catalyst in the FCC process, and more particularly, a catalyst for removing nitrogen oxides having excellent performance and durability through a simple process and excellent price competitiveness compared to conventional catalysts for removing nitrogen oxides. It relates to a method for producing a catalyst for removing nitrogen oxides using a waste FCC process catalyst that can be easily prepared.

Nitrogen oxides (NO _X ) are mainly produced during the combustion of fossil fuels, and are generated from mobile sources such as ships and automobiles, or stationary sources such as power plants or incinerators. These nitrogen oxides are pointed out as one of the main culprits that pollute the atmosphere by the formation of acid rain and smog, and recently, regulations on air pollution have become stricter and research to reduce nitrogen compounds such as nitrogen oxides by using reducing agents in response. There is a lot going on.

Among them, a selective reduction catalyst using ammonia as a reducing agent, titanium oxide (TiO ₂ ) carrier and vanadium oxide (V ₂ O ₅ ) as active catalyst components is widely used as a method of removing nitrogen compounds discharged from the fixed source. Is being used.

In the case of a titania-based selective reduction catalyst using ammonia as a reducing agent (hereinafter, used together with'titanium dioxide'), the denitration efficiency is excellent at 400 ℃ or higher, so the catalyst is installed in a place where the exhaust gas temperature is 400 ℃ or higher, or 400 ℃ When the catalyst is to be used at the following low temperature, a method of artificially increasing the temperature of the exhaust gas is used.

In this way, if the temperature of use of the catalyst is limited to 400 ℃ or higher, the application to which the catalyst can be installed is limited, and in the case of exhaust gas below 400 ℃, it is economical due to an increase in operating cost and a device to artificially increase the temperature of the exhaust gas. There is a problem that causes loss.

As a typical solution to this, when tungsten, molybdenum, etc. are added, the low-temperature characteristics are improved and the sulfur poisoning resistance is also improved, and tungsten, molybdenum, etc. are also added and used (Korean Patent Publication No. 2002-0057941). , Korean Patent Laid-Open Patent No. 2011-0055533), in this case, the amount of tungsten and molybdenum used in this case is excessively required, so that the catalyst price is inevitable. As another method, it is possible to improve the low-temperature characteristics of the catalyst by replacing tungsten as a cocatalyst with antimony. However, according to the conventional method, since a method of impregnating vanadium and antimony into the calcined titania powder is used, there is a problem of undergoing several steps.

Accordingly, there is a need to develop a manufacturing method that can easily produce a catalyst for removing nitrogen oxides having excellent performance and durability through a simple process.

Meanwhile, in the Fluidized Catalytic Cracking (FCC) process, diesel or diesel fractions produced in the crude oil distillation process are decomposed into gasoline or naphtha fractions by contacting them with a catalyst in a fluidized bed reactor. As the demand for gasoline increases due to the increase in automobiles and the demand for naphtha increases due to the development of the petrochemical industry, the scale of operation of the FCC process has increased, and the FCC process is the largest among the petrochemical processes.

In the FCC process, a spherical catalyst made by mixing zeolite Y with silica-alumina is used. Since zeolite particles are contained in the large pores of silica-alumina, the large reactant is first decomposed at the silica-alumina acid point, and then diffuses into the pores of the zeolite and is converted into a branched hydrocarbon having a high octane number. Recently, in order to improve the thermal stability of the zeolite and reduce carbon deposition in the decomposition process, a catalyst of the FCC process is made from ultra-stable zeolite Y (Ultra Stable Y; USY) manufactured by partially eluting aluminum.

However, even though the contact time is only a few seconds, this catalyst is severely degraded by carbon deposition, so it is recovered with a cyclone after the first use, sent to a regenerator, and put in air to burn and remove the deposited carbon, and then used again. The catalyst activity gradually decreases due to thermal fatigue accumulated in the process of use and regeneration and wear in the flow process, and the carbon deposition in the pores is not completely removed.Therefore, in the fluidized bed catalytic reactor, a certain amount of used catalyst is supplied while supplying a certain amount of new catalyst. By removing it, the catalytic activity is kept constant.

As such, the FCC process catalyst discarded after use has almost no other components other than silica and alumina, so there is no risk of pollution, and it has excellent mechanical strength, so it is usually fired in air to remove the deposited carbon and then used as a raw material for cement production, or for making bricks. B. Recycling is being considered as another raw material for zeolite synthesis, but the amount of generation is so high and economical is low that the added value of the FCC process waste catalyst is very low, such as mixing it with limestone and disposing it.

Therefore, research and development that can be used at high added value by using a large amount of waste catalysts discharged from the FCC process is still needed.

Korean Patent Publication No. 2002-0057941 (Publication date: 2002.07.12) Korean Patent Publication No. 2011-0055533 (Publication date: 2011.05.25)

The main object of the present invention is a catalyst for removing nitrogen oxides using a waste FCC process catalyst that can easily manufacture a catalyst for removing nitrogen oxides having excellent performance and durability through a simple process and excellent price competitiveness compared to conventional catalysts for removing nitrogen oxides. It is to provide a method of manufacturing.

In order to achieve the above object, an embodiment of the present invention is (a) 100 parts by weight of titanium dioxide to 400 parts by weight of titanium dioxide having an anatase-type crystal structure based on 100 parts by weight of the FCC process waste catalyst, vanadium precursor 1 Mixing parts by weight to 20 parts by weight, 5 parts by weight to 30 parts by weight of antimony precursor, and 50 parts by weight to 200 parts by weight of casting dust, and adding water to form clay for molding; (b) molding the clay for molding; And (c) drying and firing the molded product to form a catalyst, wherein the FCC process waste catalyst is aluminum oxide 15 wt% to 60 wt%, silicon dioxide 35 wt% to 80 wt% based on the total weight of the waste catalyst. % And 0.1% to 10% by weight of vanadium pentoxide, and a method of preparing a catalyst for removing nitrogen oxides.

In a preferred embodiment of the present invention, the vanadium precursor is selected from the group consisting of vanadium oxide (V ₂ O ₅ ), ammonium vanadate (NH ₄ VO ₃ ) and mixtures thereof, and the antimony precursor is antimony trichloride (SbCl ₃ ), consisting of antimony contaminated (SbCl ₅ ), antimony acetate [(CH ₃ CO ₂ ) ₃ Sb], antimony methoxide [Sb(OCH ₃ ) ₃ ] and antimony ethoxide [Sb(OC ₂ H ₅ ) ₃ ] It may be characterized in that at least one selected from the group.

In a preferred embodiment of the present invention, the method for preparing the catalyst for removing nitrogen oxides comprises the steps of: (i) heat-treating the FCC process waste catalyst at 300°C to 400°C before step (a); (ii) washing the heat-treated waste FCC process catalyst with fine bubbles; (iii) washing the washed waste catalyst with microbubbles of an acidic solution or a basic solution; (iv) washing the washed waste catalyst with water at 45 ℃ ~ 85 ℃ with water; And (v) it may be characterized in that it further comprises a pretreatment step including the step of drying the washed waste catalyst.

In a preferred embodiment of the present invention, the drying of step (c) is carried out at 80° C. to 120° C., and the sintering is performed at 400° C. to 700° C. for 1 hour to 10 hours. Method for producing a catalyst.

The production method of the catalyst for removing nitrogen oxides according to the present invention uses a waste catalyst discharged from the FCC process as a main raw material, and anatase-type titanium dioxide, vanadium, and antimony are mixed at a specific mixing ratio, and casting dust, which is a waste foundry, is used as a binder. By manufacturing a denitration catalyst, it has excellent price competitiveness compared to conventional catalysts for removing nitrogen oxides, and at the same time, it is possible to use the waste catalyst discharged from the FCC process and the casting dust, which is a waste generated in the foundry, with high added value. Performance and durability through a simple manufacturing process There is an effect of being able to easily manufacture this excellent catalyst for removing nitrogen oxides.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by an expert skilled in the art to which the present invention belongs. In general, the nomenclature used in this specification is well known and commonly used in the art.

Throughout the specification of the present application, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

The present invention is (a) 100 parts by weight of titanium dioxide having an anatase-type crystal structure with respect to 100 parts by weight of the FCC process waste catalyst, 1 part by weight of vanadium precursor to 20 parts by weight, 5 parts by weight of antimony precursor- A raw material mixing step of mixing 30 parts by weight and 50 parts by weight of casting dust to 200 parts by weight, and adding water to form clay for molding; (b) molding the clay for molding; And (c) drying and firing the molded product to form a catalyst, wherein the FCC process waste catalyst is aluminum oxide 15% by weight to 60% by weight, silicon dioxide 35% by weight to 80% by weight, and vanadium pentoxide 0.1% by weight It relates to a method for producing a catalyst for removing nitrogen oxides, characterized in that containing% to 10% by weight.

More specifically, the method for producing a catalyst for removing nitrogen oxides according to the present invention recycles components useful for removing nitrogen oxides contained in the waste catalyst discharged from the FCC process and at the same time converts waste dust generated during casting into a catalyst binder. It is used and manufactured by additionally mixing components that can improve nitrogen oxide removal efficiency in a specific amount, so it has excellent price competitiveness compared to conventional catalysts for removing nitrogen oxides, and at the same time, the waste catalyst discharged from the FCC process and the cast waste dust are high added value. It can be used as, and a catalyst for removing nitrogen oxides excellent in performance and durability can be easily prepared through a simple process.

The FCC process waste catalyst is a waste catalyst discharged and disposed of from the FCC process of an oil refinery, aluminum oxide (Al ₂ O ₃ ) 15% by weight to 60% by weight, silicon dioxide (SiO ₂ ) 35% by weight to 80% by weight, and Vanadium pentoxide (V ₂ O ₅ ) contains 0.1 wt% to 10 wt%, has a specific surface area of 5 m ² /g to 200 m ² /g, and a pore size of 100 Å to 180 Å. In addition, although there are differences depending on the manufacturer, some may include Y-type or ZSM-5 type zeolite.

The aluminum oxide (Al ₂ O ₃ ) contained in the FCC process waste catalyst has a wide specific surface area of 100 m ² /g to 500 m ² /g even at a firing temperature of 500 °C, and has a different gamma at 700 °C to 800 °C. It has the advantage of excellent thermal stability as it changes from γ) type to alpha (α) type.

In addition, the vanadium pentoxide contained in the waste FCC process catalyst was deposited in the process of contacting the FCC process catalyst with the vanadium originally contained in crude oil, and is a major reaction in the reaction of nitrogen oxide and ammonia as a reducing agent to reduce it to nitrogen and water. It serves as an active material that acts as a catalyst.

On the other hand, the method for producing a catalyst for removing nitrogen oxides according to the present invention may further perform a pretreatment step for removing various impurities bound to the surface of the FCC process waste catalyst before mixing the raw materials. At this time, the pretreatment is (i) heat-treating the waste catalyst at a temperature at which impurities such as oil components, carbon, sulfur components, etc. can be effectively removed, preferably at 300°C to 400°C [Step (i)], and the heat-treated The waste catalyst is washed with fine bubbles in pure water [Step (ii)], and then the washed waste catalyst is washed with bubbles of an acidic or basic solution [Step (iii)]. The washed waste catalyst is washed with water using pure air bubbles of 45° C. to 85° C. [Step (iv)], and the washed waste catalyst is dried [Step (v)].

In step (ii), heat-treated impurities deposited on the waste catalyst can be removed, and in step (iii), alkali metals such as Na and K, alkaline earth metals such as Mg and Ca, and arsenic are used to reduce catalytic active sites. Inert substances such as heavy metals, SO ₂ , and sulfur compounds such as SO ₃ can be removed. In this case, an aqueous sulfuric acid solution may be used as the acidic solution, aqueous ammonia may be used as the basic solution, and the concentration of the aqueous sulfuric acid solution and the aqueous ammonia solution may have a value in the range of 0.5% to 1.5%. When the concentration is less than 0.5%, the cleaning effect of the inactive material is deteriorated, and when the concentration is more than 1.5%, active metals such as vanadium or tungsten contained in the waste catalyst may be removed together, which is not preferable.

The waste catalyst washed with an acidic or basic solution is washed with pure water [Step (iv)]. The acidic or basic solution and residual inactive substances remaining in the waste catalyst may be removed by washing with water. In this case, water washing can efficiently remove the acidic or basic solution and residual inactive substances, etc. remaining by using hot water at 45°C to 85°C. If the temperature of the hot water is less than 45 ℃, the removal efficiency of inactive substances is low, and if it exceeds 85 ℃, NH ₃ , alkali metals or alkaline earth metals that may remain in the waste catalyst react with water to generate salts. I can.

In the above-described pretreatment step, it may be carried out using pure microbubbles and microbubbles of an acidic or basic solution. The microbubbles generate microbubbles (average diameter of 200 μm or less) in the cleaning solution by passing compressed air through a porous body having a plurality of pores, thereby effectively removing inert substances deposited in the fine pores of the waste catalyst.

Thereafter, in step (v), the spent catalyst may be dried using hot air of 40° C. to 90° C. and then pulverized. Since NH ₃ , alkali metals or alkaline earth metals that may remain in the waste catalyst may react with water to generate salts, it is preferable to completely remove water on the waste catalyst through the drying process.

The FCC process waste catalyst pretreated as described above is mixed with titanium dioxide, vanadium precursor, antimony precursor, and casting dust, and water is added thereto to perform a raw material mixing step of forming clay for molding [Step (a)] .

The titanium dioxide may be an anatase type or a mixed form of anatase and rutile, but it is preferable to use an anatase type in terms of reducing side reactions with ammonia, and 100 to 400 parts by weight based on 100 parts by weight of the FCC process waste catalyst, Preferably 150 to 350 parts by weight are mixed. If less than 100 parts by weight of titanium dioxide is mixed with respect to 100 parts by weight of the waste catalyst in the FCC process, it is difficult to form the desired shape during catalyst molding, and the nitrogen oxide removal efficiency may be lowered, and when mixed in excess of 400 parts by weight There may be a problem in that the nitrogen oxide removal efficiency is insignificant compared to the amount of titanium dioxide added, and the manufacturing cost is increased.

In addition, the present invention is based on 100 parts by weight of the FCC process waste catalyst in order to improve the nitrogen oxide removal performance at low temperatures, 1 part by weight to 20 parts by weight of a vanadium precursor, preferably 2 parts by weight to 15 parts by weight, and 5 parts by weight of an antimony precursor. Part to 30 parts by weight, preferably 10 to 25 parts by weight, are mixed. At this time, when the vanadium precursor and the antimony precursor are mixed in less than 1 part and 5 parts by weight, respectively, with respect to 100 parts by weight of the FCC process waste catalyst, the removal of nitrogen oxides is insufficient at low temperature, and the mixture exceeds 20 parts by weight and 30 parts by weight. In this case, there is a problem that side reactions proceed and may be generated as sulfur dioxide or sulfur trioxide.

At this time, the vanadium precursor may be vanadium oxide (V ₂ O ₅ ) or ammonium vanadate (NH ₄ VO ₃ ), and the antimony precursor is antimony trichloride (SbCl ₃ ), antimony pentaminated (SbCl ₅ ), antimony acetate [ (CH ₃ CO ₂ ) ₃ Sb], antimony methoxide [Sb(OCH ₃ ) ₃ ] or antimony ethoxide [Sb(OC ₂ H ₅ ) ₃ ]. However, the vanadium precursor and the antimony precursor are not limited to the materials listed above, and can be applied as long as they are soluble in water to be used.

Casting dust is the dust generated in the foundry and recovered through a dust collector. In general, a foundry factory makes green sand by mixing 80% to 85% by weight of sand, 8% to 10% by weight of bentonite, 3.5% to 6% by weight of charcoal, and 3% to 4% by weight of water. The green sand is molded and the molten metal is used for the green sand molding, and the molten metal is cooled and sand is removed to finish the casting. In this process, dust is generated during cooling and sand removal, and such dust is collected through a dust collection hood and filtered through a filter to prevent contamination of the environment. The dust filtered by the filter is mainly composed of bentonite, silicon oxide, aluminum oxide, and iron oxide, and contains impurities.If these are collected and discarded, environmental pollution is prevented, but there is a problem that resources are continuously wasted because they cannot be recycled as a blended component. In addition, there is a problem in that industrial resources are wasted and the consumption of bentonite is increased, resulting in an increase in manufacturing cost.

On the other hand, conventionally, kaolin, zeolite, clay, etc. are used as inorganic binders to increase the mechanical strength during extrusion molding of a catalyst for removing nitrogen oxides, but when these raw materials are added in large amounts, the mechanical strength improves, but the nitrogen oxide removal efficiency decreases rapidly. do.

Accordingly, in the present invention, as a binder of the catalyst, by manufacturing the catalyst using waste dust generated in the casting process, the waste can be recycled as a useful resource and the nitrogen oxide removal efficiency can be improved.

Specifically, silicon oxide and aluminum oxide contained in the casting dust are similar in components to the waste catalyst in the FCC process, and thus have affinity with the waste catalyst in the FCC process, improve catalyst durability, and the bentonite contained in the casting dust is water. When mixed with, it can form a highly viscous dough. Accordingly, clay-based kneading cannot be performed using only the FCC process waste catalyst, and only molding dust is added as a binder to produce viscosity that can be molded. In addition, the casting dust has a high drying strength during molding and drying, and thus may serve as a reinforcing agent to increase the strength of the catalyst.

The casting dust separates foreign substances by contacting water before being mixed with the FCC process waste catalyst. For example, aluminum waste dust may be passed through water to produce dust. Casting dust from which foreign substances have been removed can be used after drying at room temperature to 80°C.

In the method for preparing the catalyst for removing nitrogen oxides of the present invention, the content of the casting dust to be mixed is 50 parts by weight to 200 parts by weight, preferably 80 to 150 parts by weight based on 100 parts by weight of the FCC process waste catalyst. I can. If less than 50 parts by weight of casting dust is mixed with respect to 100 parts by weight of the waste catalyst in the FCC process, the catalyst cannot properly function as an adhesive, and if it exceeds 200 parts by weight, the nitrogen oxide removal efficiency may decrease. .

At this time, the above-described FCC process waste catalyst, titanium dioxide, vanadium precursor, antimony precursor, and casting dust may further include a step of pulverizing the average particle diameter to a size of 100 mesh to 200 mesh before or after mixing to be uniformly mixed. . The grinding method may be used without limitation, as long as it is a known grinding method such as a ball mill.

Thereafter, when the FCC process waste catalyst and titanium dioxide, vanadium precursor, antimony precursor, and casting dust are mixed, a raw material mixing step of forming clay for molding is performed by adding water. The water may be mixed with the raw material mixture while adjusting to have a suitable fluidity according to the molding method to form a clay for molding, and preferably, it may be added in an amount of 10% to 40% by weight based on the total weight of the clay for molding, It is not limited thereto.

In addition, the raw material mixing step may additionally contain generally known additives added when preparing a catalyst, and these additives can be selected without difficulty by those skilled in the art to which the present invention belongs, for example, methyl It may be inorganic and organic binders such as cellulose, grease fiber, and clay, dispersants, plasticizers, lubricants, neutralizing agents, and the like.

The molding step according to the present invention is a step of molding a catalyst having a desired shape from the molding clay obtained in the raw material blending step, and the shape of the catalyst according to the present invention is granular or monolithic by extrusion molding the molding clay ( monlith), or manufactured in various forms such as slate, plate, and pellet.

Alternatively, when the selective catalyst of ammonia according to the present invention is actually applied, it may be coated on structures such as honeycomb, metal plate, metal fiber, ceramic filter, and metal foam.

The molded product formed into a predetermined shape in the molding step is dried and then calcined to prepare a catalyst. At this time, drying may be performed at 80° C. to 120° C. for 10 to 24 hours, and then calcined at 400° C. to 700° C. for 1 to 10 hours to finally prepare a catalyst for removing nitrogen oxides.

The catalyst prepared by the manufacturing method of the present invention described above has a specific surface area (BET) of 50 m ² /g ~ 100 m ² / and a pore size of 100 Å ~ 300 Å, so that the removal efficiency of nitrogen oxides is excellent as well as high It has excellent thermal and chemical stability at temperature, so it can maintain nitrogen oxide removal performance for a long time as a selective reduction catalyst. In addition, since the waste catalyst, which is a by-product of the oil refinery, and the casting dust, which is a by-product of the foundry, are used, it is advantageous in terms of cost used in the manufacture of the catalyst.

Hereinafter, the present invention will be described in more detail through examples. These examples are for illustrative purposes only and should not be construed as limiting the scope of the invention by these examples.

< Example 1 to 7 and Comparative example 1 and 4>

The waste catalyst [SK Chemical Co., Ltd.] of the FCC process used in the Examples and Comparative Examples of the present invention performed a pretreatment step, and the contents of the main components of the waste catalyst subjected to the pretreatment step are as shown in Table 1 below. . On the other hand, the casting dust discharged from the foundry factory located in the Namdong Industrial Complex was also washed with water and impurities were removed. Casting dust having anatase-type titanium dioxide, vanadium pentoxide, antimony pentaminated and the main components of Table 2 is mixed in 100 parts by weight of the waste catalyst in the contents of Table 3, and then ball mill pulverized so that the average particle size thereof is 150 mesh. Then, the pulverized mixture was put into a conventional pressurized kneader (kneader) together with water and kneaded to obtain clay for molding. The obtained clay was extruded into a monolith (150 mm × 150 mm × 150 mm, partition wall thickness: 0.7 mm, partition wall pitch 4.0 mm) by a screw-type extrusion molding machine, and dried at 110° C. for 15 hours to completely remove moisture. Then, a catalyst was prepared by firing for 3 hours at a temperature of 550° C. in an air atmosphere.

ingredient SiO ₂ Al ₂ O ₃ V ₂ O ₅ NiO MoO ₃ Fe ₂ O ₃ Etc Content (average weight %) 36.0 20.0 5.5 10.0 2.5 0.5 25.5

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Bentonite Etc Content (average weight %) 8.0 54.0 1.20 28.0 8.80

division Waste catalyst
(Part by weight) Titanium dioxide
(Part by weight) Vanadium pentoxide
(Part by weight) Antimony Pollution
(Part by weight) Casting dust
(Part by weight) Example 1 100 200 10 10 100 Example 2 100 200 10 10 180 Example 3 100 200 10 10 70 Example 4 100 120 10 10 100 Example 5 100 380 10 10 100 Example 6 100 200 1.5 10 100 Example 7 100 200 20 10 100 Comparative Example 1 100 - 10 10 100 Comparative Example 2 100 200 - 10 100 Comparative Example 3 100 200 10 - 100 Comparative Example 4 100 200 10 10 -

[ Experimental example 1: Measurement of mechanical strength of catalyst]

In order to determine the mechanical strength of the catalysts prepared in Examples and Comparative Examples, an Instron instrument (Instron Universal Testing Instrument Model 4201, Instron Co., Ltd.) was prepared with a tetrahedral type catalyst having a size of 25.4 mm × 25.4 mm × 25.4 mm and used for strength measurement. ) Was used to measure the axial strength and side strength of the catalyst, and are shown in Table 4. At this time, the catalyst A used in Table 4 is a catalyst for removing nitrogen oxides from A company that is currently sold.

[ Experimental example 2: of the catalyst Wear resistance Measure]

The catalysts prepared in Examples and Comparative Examples were mounted in a domestic bituminous coal power plant to measure the degree of wear resistance against dust contained in the actual exhaust gas. The location where the catalyst is installed is located in front of the power plant dust collector and contains a lot of dust (17.4 g/Nm ³ ), and the exhaust gas flow rate is 16 m/sec, which is very high. Table 4 shows the results of measuring the wear rate of the catalysts of Examples and Comparative Examples after exposure to high-speed dust for 30 days. At this time, the catalyst A used in Table 4 is a catalyst for removing nitrogen oxides from A company that is currently sold.

[ Experimental example 3: Measurement of nitrogen oxide removal rate]

The catalysts of Examples and Comparative Examples were mounted in a low-pressure difference reactor, and a mixed gas consisting of 3.0% oxygen concentration, 200 ppm nitrogen oxide, 200 ppm ammonia, and nitrogen as a balance gas was prepared at a rate of 10 liter per minute. It was injected at a flow rate. The reaction temperature was raised at intervals of 200 ℃, 300 ℃ and 450 ℃, and the concentration of nitrogen oxide was measured using a measuring instrument using the non-dispersive infrared method is shown in Table 4. At this time, the catalyst A used in Table 4 is a catalyst for removing nitrogen oxides from A company that is currently sold.

division Mechanical strength Wear resistance measurement Nitrogen oxide removal rate (%) Axial strength
(kg/cm ² ) Side strength
(kg/cm ² ) Wear rate
(%) 200 ℃ 300 ℃ 450 ℃ Example 1 41 32 15.7 78.1 96.2 98.0 Example 2 54 48 17.2 68.4 92.4 91.3 Example 3 33 12 12.8 80.1 97.0 98.6 Example 4 38 18 14.4 71.2 94.4 97.5 Example 5 43 35 16.6 70.8 93.2 94.7 Example 6 42 30 15.5 60.6 87.6 91.1 Example 7 39 30 14.8 68.5 96.5 98.8 Comparative Example 1 29 11 7.0 59.5 85.0 87.2 Comparative Example 2 39 33 15.9 61.0 81.0 84.4 Comparative Example 3 40 33 15.1 31.2 71.8 79.0 Comparative Example 4 - - - - - - Commercial A catalyst 32 12 12.5 62.2 89.0 92.5

As shown in Table 4, the catalysts prepared in Examples 1 to 7 were found to have excellent mechanical strength, wear resistance, and denitrification efficiency compared to the catalysts prepared in Comparative Examples 1 to 4, and in particular, in Comparative Example 4, an extrusion-molded catalyst Was damaged, and the mechanical strength, wear resistance, and nitrogen oxide removal rate could not be measured.

Therefore, the catalyst for removing nitrogen oxides prepared by the manufacturing method according to the present invention has excellent price competitiveness compared to the conventional catalyst for removing nitrogen oxides, and at the same time, it is possible to use the waste catalyst discharged from the FCC process with high added value. It was confirmed that a catalyst for removing nitrogen oxides excellent in durability could be easily prepared.

As described above, although the present invention has been described by a limited embodiment, the present invention is not limited thereto, and the technical spirit and subsequent description of the present invention by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equal range of the claims to be made.

Claims (4)

(a) 150 parts by weight to 350 parts by weight of titanium dioxide having an anatase-type crystal structure, 2 parts by weight to 15 parts by weight of a vanadium precursor, 10 parts by weight to 25 parts by weight of an antimony precursor based on 100 parts by weight of the FCC process waste catalyst And mixing 80 parts by weight to 150 parts by weight of casting dust, and adding water to form clay for molding.
(b) molding the clay for molding; And
(c) drying and firing the molded product to form a catalyst,
The FCC process waste catalyst is nitrogen oxide, characterized in that it contains 15% to 60% by weight of aluminum oxide, 35% to 80% by weight of silicon dioxide, and 0.1% to 10% by weight of vanadium pentoxide based on the total weight of the waste catalyst. Method for producing a catalyst for removal.
The method of claim 1,
The vanadium precursor is at least one selected from the group consisting of vanadium oxide (V ₂ O ₅ ), ammonium vanadate (NH ₄ VO ₃ ) and mixtures thereof, and the antimony precursor is antimony trichloride (SbCl ₃ ), antimony pentachloride 1 selected from the group consisting of (SbCl ₅ ), antimony acetate [(CH ₃ CO ₂ ) ₃ Sb], antimony methoxide [Sb(OCH ₃ ) ₃ ] and antimony ethoxide [Sb(OC ₂ H ₅ ) ₃ ] Method for producing a catalyst for removing nitrogen oxides, characterized in that more than species.
The method of claim 1,
The method of preparing the catalyst for removing nitrogen oxides includes: (i) heat-treating the FCC process waste catalyst at 300°C to 400°C before step (a); (ii) washing the heat-treated waste FCC process catalyst with water using air bubbles; (iii) washing the washed waste catalyst using bubbles of an acidic solution or a basic solution; (iv) washing the washed waste catalyst with water using bubbles of 45 ℃ ~ 85 ℃; And (v) a pretreatment step comprising the step of drying the washed waste catalyst.
The method of claim 1,
The method of producing a catalyst for removing nitrogen oxides, characterized in that the drying in step (c) is carried out at 80° C. to 120° C., and the sintering is performed at 400° C. to 700° C. for 1 hour to 10 hours.