Wear-resistant fluidized bed catalyst as well as preparation method and application thereof

Abstract

The invention provides a wear-resistant fluidized bed catalyst and a preparation method and application thereof.The wear-resistant fluidized bed catalyst is composed of a catalyst core and at least one coating layer coating the outer layer of the catalyst core, the core and the coating layer are both formed by mixing and supporting active ingredients, carriers and carrier additives, and the wear-resistant fluidized bed catalyst is prepared through the steps of drying, spraying and roasting. Silica sol is selected as a carrier of the catalyst, a large specific surface area is provided for attachment of active ingredients, meanwhile, the mechanical strength of the catalyst is improved, the wear resistance of the catalyst is greatly superior to that of a traditional fluidized bed catalyst, and the wear loss in the fluidized bed operation process is reduced. More importantly, active components are embedded into the core and the coating layer of the catalyst, so that long-time catalytic efficiency can be maintained in a fluidized bed reaction process, and the product yield is further improved. Meanwhile, due to the design, the service life of the catalyst is prolonged, and the stability of the catalyst in continuous operation is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluidized bed catalysts, and particularly relates to a wear-resistant fluidized bed catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Fluidized bed catalytic technology has been widely used in the fields of petrochemical industry, coal chemical industry, and fine chemical industry, such as petroleum catalytic cracking, methanol to olefins (MTO), ethylene chlorination, alkane catalytic dehydrogenation, ammoxidation of aromatic hydrocarbons to aromatic nitriles, oxidation of propylene to acrylic acid, ammoxidation of propylene to acrylonitrile, oxidation of butane or benzene to maleic anhydride, oxidation of xylene or naphthalene to phthalic anhydride, oxidation of sulfur dioxide, etc. In these processes, the performance of the fluidized bed catalyst is the key to determining the overall process technology level.

[0003] In a fluidized bed reactor, the catalyst is in the form of microspherical particles and forms a turbulent motion under the drive of a high-speed gas flow, and fully contacts with the reactants, thereby realizing the continuous progress of the reaction. However, inside the reactor, due to the frequent collision and friction between catalyst particles, between particles and the inner wall or internal components, the catalyst particles will be continuously worn and the particle size will decrease. In addition, factors such as the temperature, pressure, reaction gas, and generated water vapor in the reactor will also cause losses to the catalyst. These worn or lost fine catalyst particles are entrained out of the reactor by the gas flow and recovered through a supporting cyclone separator. Therefore, it is necessary to frequently supplement the catalyst to maintain the normal operation of the reactor, increasing the production cost.

[0004] If the mechanical strength of the catalyst itself is insufficient, it will lead to a serious phenomenon of catalyst leakage, affecting the reasonable distribution of the catalyst in the dense phase section and the dilute phase section of the reactor, and further affecting the normal operation of the device. Therefore, on the premise of ensuring that the catalyst has high activity, it is also necessary to have good mechanical strength and wear resistance. This can not only extend the service life, maintain a high product yield, increase product revenue, but also significantly reduce the amount of catalyst supplementation and avoid unnecessary increase in production cost.

[0005] Some prior arts have provided some preparation methods for wear-resistant fluidized bed catalysts. For example, Patent CN104437597B provides a fluidized bed catalyst for high wear-resistant catalytic cracking of naphtha to olefins and a preparation method thereof. After mixing kaolin, binder, phosphorus oxide, rare earth element, and transition metal element in proportion, a fluidized bed catalyst with relatively high anti-wear performance is obtained through spray drying and calcination.

[0006] Patent CN105195186A discloses a preparation method of a wear-resistant microsphere catalyst for an acrylic acid (ester) fluidized bed. A mixed slurry containing metal salts such as cesium salt, barium salt, strontium salt, magnesium salt, vanadium salt, as well as alumina, a carrier agent, a binder, and aluminum sol is stirred, spray-dried, and calcined to obtain a catalyst with high activity, good wear resistance, uniform distribution of active components, and long service life.

[0007] Patent CN106268890B provides an ammoxidation fluidized bed catalyst for aromatics, a preparation method, and uses thereof. The ammoxidation fluidized bed catalyst for aromatics obtained by combining a carrier and different metals in a certain component ratio and addition sequence has good wear resistance and a low catalyst loss rate.

[0008] Patent CN 101306391 B provides a method for preparing a molecular sieve fluidized bed catalyst with high wear resistance. After uniformly mixing a molecular sieve, a binder, a carrier material, catalyst fines, and a liquid medium to form a suspension, a catalyst with relatively high wear resistance is obtained through spray drying and calcination.

[0009] Patent CN 107971024 B provides a preparation method of a fluidized bed catalyst. By coating a layer of alumina on the outer surface of the catalyst, the wear resistance of the fluidized bed catalyst can be improved to a certain extent. Similarly, Patent CN108295894A provides a preparation method of a core-shell type wear-resistant catalyst and the catalyst. A core is prepared by spray drying and calcination using a binder and clay, and then a catalyst slurry is coated on the surface of the core to form a shell, obtaining a core-shell type catalyst with high wear resistance.

[0010] Although the preparation methods of molecular sieve-based fluidized bed catalysts mentioned in existing patents can enhance wear resistance to a certain extent, for catalysts containing key active components, such as catalysts used in propylene oxidation, ammoxidation, epoxidation, etc., introducing high-strength binders either inside or on the surface of the catalyst will inevitably reduce the space occupied by the active components, thereby affecting the overall performance of the catalyst.

[0011] Although some patented technologies have been dedicated to solving the wear resistance problem of fluidized bed catalysts, currently, the optimization of fluidized bed catalysts still needs to be carried out according to different reaction process requirements. While further improving wear resistance, the catalyst also needs to maintain an appropriate specific surface area and uniform distribution of catalytic active components to ensure its catalytic activity and product yield. Such optimization is of crucial significance for enhancing the economic benefits and technical level of fluidized bed catalysts. Summary of the Invention

[0012] In view of the problems existing in the existing fluidized bed catalysts, such as easy abrasion, low proportion of active components, and low catalytic activity, the present invention provides a wear-resistant fluidized bed catalyst, its preparation method and application. The wear-resistant fluidized bed catalyst is composed of a catalyst core and at least one coating layer wrapped outside the core. Both the core and the coating layer use silica sol as a carrier, and after being mixed with active components, they are made through the process steps of drying spray and calcination. This catalyst has excellent mechanical strength and far exceeds traditional fluidized bed catalysts in terms of wear resistance, and can effectively reduce losses during the operation of the fluidized bed. Moreover, since both the core and the coating layer of this catalyst are loaded with active components, it ensures that it can continuously play its catalytic role in the fluidized bed reaction, thereby improving the yield of the product.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] A wear-resistant fluidized bed catalyst, comprising: a catalyst core, and a coating layer covering the outside of the catalyst core, and the coating layer is at least one layer; both the core and the coating layer include active components, a carrier, and a carrier additive; the carrier is silica sol; the carrier additive of the core is an aluminum-containing compound, and the carrier additive of the coating layer is a nano binder.

[0015] In some embodiments, the aluminum-containing compound is one of aluminum sol, pseudo-boehmite, alumina, aluminum nitrate, aluminum hydroxide, and aluminum phosphate.

[0016] In some embodiments, the carrier included in the core is high-particle-size silica sol, and the carrier included in the coating layer is low-particle-size silica sol; in the high-particle-size silica sol, the content of silicon dioxide is 40-50%; the average particle size of the high-particle-size silica sol ≥20nm, the specific surface area is 100-150m 2 / g, the viscosity is 8-15cp (@25°C), and the pH is 8-10; in the low-particle-size silica sol, the content of silicon dioxide is 25-35%; the average particle size of the low-particle-size silica sol is 12-20nm, and the specific surface area is 200-250m 2 / g, the viscosity ≤22cp (@25°C), and the pH value is 8-10.

[0017] In some embodiments, the thickness of the coating layer is 10-60 microns; and / or, the size of the nano binder is 1-100nm; and / or, the nano binder is one of nano gel, nano clay, and nano carbon fiber tube.

[0018] The present invention also provides a method for preparing a wear-resistant fluidized bed catalyst for preparing the above-mentioned wear-resistant fluidized bed catalyst, including: a catalyst core forming step and a catalyst coating forming step; the catalyst core forming step includes: first, formulating the active component, the silica sol and the aluminum-containing compound into a mixed slurry in a certain proportion, forming microsphere particles after drying and spraying, and then obtaining the catalyst core after calcination and activation; the catalyst coating forming step includes: formulating the active component, the silica sol and the nano binder into a coating slurry in a certain proportion, and then mixing with the catalyst core so that the surface of the catalyst core is uniformly coated with the coating slurry to form a mixed suspension; the mixed suspension is sequentially subjected to spray drying and calcination activation to obtain the wear-resistant fluidized bed catalyst; repeating the catalyst coating forming step multiple times can obtain a wear-resistant fluidized bed catalyst with a multi-layer coating structure.

[0019] In some embodiments, in the catalyst core forming step, the specific preparation steps of the mixed slurry include: adding a compound containing a specific metal element into deionized water in a certain proportion and sequence for dissolution to form an active component aqueous solution, and keeping it warm for standby; then taking a certain amount of the active component aqueous solution, sequentially adding high-particle-size silica sol and the aluminum-containing compound for mixing, and continuously stirring under a certain heat tracing temperature condition to form a uniform slurry liquid, and then obtaining the mixed slurry after aging.

[0020] In some embodiments, the temperature of the deionized water for dissolving the compound containing the specific metal element is 55-85 °C; the heat tracing temperature is 55-70 °C, the stirring time is 25-60 minutes; the aging temperature is 95-110 °C, and the time is 10-30 minutes. During the aging process, the slurry liquid is continuously stirred.

[0021] In some embodiments, in the catalyst coating forming step, the specific preparation steps of the coating slurry are: taking a certain amount of the active component aqueous solution prepared in the catalyst core forming step, adding low-particle-size silica sol and nano binder in a certain proportion and mixing evenly to obtain the coating slurry.

[0022] In some embodiments, in the catalyst core forming step and the catalyst coating forming step, the calcination activation temperature is 550-650 °C, and the time is 2-4 hours.

[0023] The present invention also provides an application of the wear-resistant fluidized bed catalyst, using the above-mentioned wear-resistant fluidized bed catalyst, or the wear-resistant fluidized bed catalyst prepared by the above preparation method, in a fluidized bed reaction process.

[0024] Compared with the prior art, the wear-resistant fluidized bed catalyst provided by the present invention, its preparation method and application have the following beneficial effects:

[0025] 1. The wear-resistant fluidized bed catalyst provided by the present invention is composed of a catalyst core and at least one coating layer on its outer part. The catalyst core and the coating layer respectively select high-particle-size silica sol and low-particle-size silica sol as carriers. After being mixed with the active component raw materials, it is prepared by drying spray and calcination activation. The low-particle-size silica sol has a higher specific surface area, which can provide more surface areas for the active components to adhere. Moreover, the high-particle-size silica sol can form a harder skeleton structure during the drying and calcination processes, which helps to improve the mechanical strength of the catalyst, enabling it to withstand the collisions and abrasions between particles during the fluidization operation of the fluidized bed. Traditional catalysts are prone to generating fine powders due to the abrasion and fragmentation between particles during the reaction process, resulting in a large loss of the catalyst and causing secondary environmental pollution caused by the fine powders. In contrast, the wear-resistant fluidized bed catalyst of the present invention not only exhibits excellent wear resistance in the catalyst evaluation test, but also can effectively reduce the loss and surface deactivation problems in a high-temperature water vapor environment. In addition, the catalyst also has active components in both the coating layer and the core, ensuring that the catalyst can maintain persistent catalytic activity during the fluidized bed reaction process and improving the product yield;

[0026] 2. For the wear-resistant fluidized bed catalyst provided by the present invention, a nano binder is introduced as a carrier additive in the components of the coating layer. On the one hand, it improves the mechanical strength and thermal stability of the coating layer. On the other hand, it utilizes the unique conductive property of the nano material to enhance the electron transport ability in the catalyst system. This improvement effectively enhances the activity and selectivity of the active components of the catalyst, thereby promoting the increase in the yield of the target product;

[0027] 3. In the preparation method of the wear-resistant fluidized bed catalyst provided by the present invention, the coating forming step of the catalyst core adopts a high-shear dispersion technology. This technology not only greatly shortens the mixing time, but also ensures that the active components, low-particle-size silica sol and nano binder can be more evenly distributed on the surface of the catalyst core, thereby forming a dense and uniform coating layer. This not only meets the performance standards of the fluidized bed catalyst, but also reduces the energy consumption cost during the preparation process, achieving a double improvement in efficiency and economy;

[0028] 4. The fluidized bed catalyst preparation method provided by the present invention realizes the precise control and optimization of the activity performance of the fluidized bed catalyst by regulating the ratio of the active components in the raw materials to silica sols with different particle sizes and nano binders. This preparation method is easy to operate, and the preparation process has high flexibility, facilitating the adjustment of the abrasion resistance and specific surface area of the catalyst according to different reaction conditions or working conditions requirements, thereby enhancing the overall reaction performance of the catalyst. In addition, this preparation method has wide applicability and can be used in the manufacture of catalyst products in a variety of fluidized bed processes, greatly expanding its application scope. This method is more in line with the production requirements of industrial scale and is suitable for wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the drawings and embodiments.

[0030] Figure 1 It is a process schematic diagram of the preparation method of the abrasion-resistant fluidized bed catalyst provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be further explained in detail below in conjunction with the description of the drawings and specific embodiments. However, the following description including the embodiments is only used to enable those of ordinary skill in the technical field to which the present invention belongs to more clearly understand the principles and essence of the present invention, and does not mean any form of limitation to the present invention.

[0032] Example 1

[0033] The present invention provides an abrasion-resistant fluidized bed catalyst, including: a catalyst core and a coating layer covering the outside of the catalyst core. The coating layer is at least one layer, preferably 2 - 3 layers.

[0034] Both the above-mentioned core and coating layer contain active components, a carrier, and a carrier additive. The carrier is silica sol, the carrier additive of the core is an aluminum-containing compound, and the carrier additive of the coating layer is a nano binder.

[0035] In some embodiments, the above-mentioned aluminum-containing compound is one of aluminum sol, pseudoboehmite, alumina, aluminum nitrate, aluminum hydroxide, and aluminum phosphate. Aluminum sol is preferably used, and commercially available products can be selected. The selection specifications of aluminum sol are as follows: the solid content is 15 - 30%; the average particle size range is 40 - 60 nm, and the particle size distribution can be multiple peaks, with a single peak being the optimal choice; the pH value is 3 - 6, and the pH value is preferably 4.5 - 5.5.

[0036] The aluminum-containing compound as a carrier additive helps to reduce the expansion of the silicon component during the forming process and improves the stability of the catalyst core.

[0037] In some embodiments, the carrier included in the above-mentioned core is high-particle-size silica sol, and the carrier included in the coating layer is low-particle-size silica sol. Commercial silica sol products can be used for both.

[0038] The selection specifications of the high-particle-size silica sol are as follows: the content of silicon dioxide is 40-50%; the average particle size ≥ 20 nm, and the particle size distribution can have multiple peaks, with a single peak being the optimal choice; the specific surface area is 100-150 m 2 / g, the viscosity is 8-15 cp (@25 °C), preferably 10-12 cp (@25 °C), the pH is 8-10, and the pH value is preferably 9-9.5.

[0039] The selection specifications of the low-particle-size silica sol are as follows: the content of silicon dioxide is 25-35%; the average particle size of the low-particle-size silica sol is 12-20 nm, and the particle size distribution can have multiple peaks, with a single peak being preferred; the specific surface area is 200-250 m 2 / g; the viscosity ≤ 22 cp (@25 °C), preferably 13-18 cp (@25 °C); the pH value is 8-10, and the pH value is preferably 9-9.5.

[0040] In some embodiments, the thickness of the above-mentioned coating layer is 10-60 microns.

[0041] In some embodiments, the size of the above-mentioned nano binder is 1-100 nm, and the nano binder can be selected from one of nano materials such as nano gel, nano clay, and nano carbon fiber tube. Nano clay or nano gel is preferably used, which can be dispersed in metal oxide grains to enhance the overall strength and thermal stability of the material.

[0042] Example 2

[0043] Based on Example 1, the present invention also provides a preparation method of the wear-resistant fluidized bed catalyst, including a catalyst core forming step and a catalyst coating forming step, as Figure 1 shown, specifically:

[0044] (1) The catalyst core forming step includes:

[0045] First, the active component, high-particle-size silica sol, and aluminum-containing compound are formulated into a mixed slurry in a certain proportion, formed into microsphere particles by drying and spraying, and then the catalyst core is obtained after calcination and activation.

[0046] (2) The catalyst coating forming step includes:

[0047] The active component, low-particle-size silica sol, and nano binder are formulated into a coating layer slurry in a certain proportion, and then mixed with the catalyst core so that the surface of the catalyst core is evenly coated with the coating layer slurry to form a mixed suspension.

[0048] The wear-resistant fluidized bed catalyst can be obtained by successively subjecting the mixed suspension to spray drying and calcination activation.

[0049] Repeating the catalyst coating and forming step multiple times can obtain a wear-resistant fluidized bed catalyst with a multi-layer coating structure.

[0050] In some embodiments, in the above catalyst core forming step, the specific preparation steps of the mixed slurry include:

[0051] S1. Add the compound containing specific metal elements to deionized water in a certain proportion and order for dissolution to form an aqueous solution of the active component, and keep it warm for standby.

[0052] The above compound containing specific metal elements is used as the raw material of the active component, and can be oxides of various metal elements or nitrates, ammonium salts, hydroxides, etc. that are easily converted into oxide forms.

[0053] Preferably, the temperature of the deionized water for dissolving the compound containing specific metal elements is 55 - 85°C.

[0054] S2. Then take a certain amount of the aqueous solution of the active component, successively add high-particle-size silica sol and aluminum-containing compound for mixing, and continuously stir for 25 - 60 minutes under a certain heat accompanying temperature condition of 55 - 70°C to form a uniform slurry liquid. Subsequently, after aging at 95 - 110°C for 10 - 30 minutes, a mixed slurry is obtained, and the slurry liquid is continuously stirred during the aging process.

[0055] In the above catalyst core forming step, the specific steps of drying by spraying and calcination activation include:

[0056] S3. Perform microsphere particle forming on the mixed slurry obtained in S2 in a high-speed spray dryer, and the obtained microsphere-shaped particles are used as the catalyst core.

[0057] Preferably, the particle size of the above microsphere-shaped particles is not greater than 45 microns.

[0058] Preferably, the spraying method of the above spray dryer can be pressure spraying, pneumatic spraying, centrifugal atomizer, etc. A centrifugal atomizer is preferred, and the control of its parameters is beneficial to controlling the particle size distribution of the catalyst, including operating conditions such as the centrifugal rotation speed frequency of the atomizer, the feeding speed, the inlet and outlet air temperatures, etc. The specific parameters are as follows: the centrifugal rotation speed frequency of the atomizer is 55 - 60 Hz; the feeding speed is 10 - 15 mL / min; the inlet air temperature is 280 - 350°C; the outlet air temperature is 150 - 190°C.

[0059] S4. Calcinate and activate the formed catalyst core in a calcination furnace for 2 to 4 hours at a temperature of about 550 to 650 °C in the furnace to finally obtain a catalyst core with high hardness and a relatively high specific surface area.

[0060] Preferably, the particle size of the above catalyst core is not greater than 45 microns.

[0061] Preferably, the calcination method can be a muffle furnace, a tube furnace, a rotary tube furnace, etc. A rotary tube furnace is preferred, which can prevent the catalyst from caking during calcination, and the control of its parameters is beneficial to controlling physical properties such as the specific surface area, pore volume, mechanical strength, and activity of the catalyst. The specific parameters are as follows: the calcination temperature is 550 to 700 °C, preferably 590 to 650 °C; the calcination time is within 1 to 6 hours, preferably 2 to 4 hours; the rotation rate of the furnace tube is 2 to 10 revolutions per minute on average, preferably 4 to 6 revolutions per minute.

[0062] Furthermore, a flowing inert gas or pure air atmosphere is used during the calcination process, which can promote the formation of a more stable metal oxide phase structure inside the catalyst particles. The preferred gas flow rate is 2 to 15 mL / min.

[0063] In some embodiments, in the above catalyst coating and forming step, the specific preparation steps of the coating slurry and the mixed suspension are as follows:

[0064] S5. Take a certain amount of the aqueous solution of the active component prepared in the catalyst core forming step (i.e., the aqueous solution of the active component prepared in S1), add silica sol with a low particle size and a nano binder in a certain proportion and mix evenly to obtain the coating slurry. Mix the coating slurry obtained in S4 evenly with the coating slurry, so that the surface of the microsphere-shaped catalyst core is evenly coated with the slurry to form a mixed suspension.

[0065] Preferably, the mixing process of the above slurry and the catalyst core uses a high-shear disperser. By using the gap between the rotor and the stator of the shearer, a strong dispersion and mixing effect is formed under high-speed rotation, which can fully mix the solid particles and the liquid material. The preferred rotation speed is 2000 to 8000 rpm.

[0066] In some embodiments, in the above catalyst coating and forming step, the specific steps of sequentially performing spray drying and calcination activation on the mixed suspension include:

[0067] S6. Form the suspension obtained in S5 in a spray dryer at a medium and low rotation speed of 40 to 50 Hz, so that the outer surface of the catalyst core is coated with a coating slurry containing the active component, silica sol, and nano materials to form a coated structure, and the thickness of the coating layer is between 10 and 60 microns.

[0068] Preferably, the spray drying process is similar to that in S3, and a centrifugal atomizer is used. The difference is that the centrifugal speed of the atomizer and the feeding speed are relatively low, the rotational speed frequency is 45 - 49 Hz, and the feeding speed is 8 - 10 mL / min.

[0069] S7. Calcinate and activate the catalyst particles with a coated structure obtained in S6 in a roasting furnace, and a fluidized bed catalyst with high wear resistance and a relatively high specific surface area can be obtained.

[0070] Preferably, similar to the calcination in S4, the calcination process in S7 uses a rotary tube furnace. The calcination time is 2 - 4 hours, the temperature inside the furnace is 550 - 650 °C, the rotation rate of the furnace tube is 4 - 6 revolutions per minute, and the gas flow rate is 4 - 10 mL / min.

[0071] Further, after step S7 is completed, in order to obtain a catalyst with a multi-layer coated structure, the following step S8 is performed: Repeat the coating operations in steps 5 to 7 above 2 to 3 times. Through this operation, a fluidized bed catalyst with a multi-layer coated structure can be prepared, thereby significantly improving the wear resistance of the catalyst.

[0072] It should be noted that the preparation method of the wear-resistant fluidized bed catalyst provided by the present invention is designed for fluidized bed reactors, and is not limited to its application in the preparation methods of other fluidized bed catalysts and different fluidized bed reaction processes. Its core purpose is to improve the wear resistance of fluidized bed catalysts and the yield of reaction products of different reactions.

[0073] Example 3

[0074] The present invention also provides the application of the wear-resistant fluidized bed catalyst. The wear-resistant fluidized bed catalyst in Example 1 or the wear-resistant fluidized bed catalyst prepared by the preparation method in Example 2 is used in fluidized bed reaction processes, such as processes for the oxidation of propylene to acrolein, the ammoxidation of propylene to acrylonitrile, and the epoxidation of propylene to propylene oxide catalysts.

[0075] The following describes the wear resistance and activity performance of the wear-resistant fluidized bed catalyst provided by the present invention in combination with specific examples.

[0076] (1) Evaluation standard for wear resistance: The present invention uses the test method of ASTM D5757-95 (using the method of air jet abrasion to judge the relative abrasion characteristics of powder catalysts) for the abrasion test of catalyst products.

[0077] The evaluation steps and parameters of the wear-resistant fluidized bed catalyst product are described in detail as follows:

[0078] The catalyst is applied to a suitable fluidized bed catalytic reaction. Under certain reaction temperature and reaction pressure, the reaction gas reacts in a loaded fluidized bed reactor to generate products. The performance evaluation of the catalyst is carried out in a fluidized bed reactor with a diameter of 1.5 feet. The filling amount of the catalyst is about 400 - 550 g, and the reaction conditions depend on the application scenarios of different fluidized bed catalysts for reactions.

[0079] (3) Activity performance evaluation criteria: The evaluation indicators include the conversion rate of reactant propylene and the yield of the generated product, as shown in the following formula:

[0080]

[0081] (1) The following takes Comparative Examples 1-1 to 1-6 and Examples 4-1 to 4-10 to illustrate the application of the wear-resistant fluidized bed catalyst provided by the present invention in the process of propylene oxidation to acrolein / acrylic acid:

[0082] Comparative Example 1-1

[0083] Referring to the preparation methods of the catalysts for propylene oxidation to acrolein and acrylic acid described in Patent CN 201010513591.4 and CN 201210576542.4, a microsphere particle catalyst suitable for a fluidized bed is prepared as follows:

[0084] Prepare 500 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add 500 g of ammonium metavanadate in small portions multiple times. Continue stirring until it is completely dissolved, then successively add 400 g of silica sol with a concentration of 40 wt% and 400 g of aluminum sol with a concentration of 20 wt% as the carrier liquid. After mixing evenly, prepare Material A, and keep the temperature of the material between 45 - 65°C. Then prepare another 150 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, successively add 200 g of ferric nitrate nonahydrate, 140 g of bismuth nitrate pentahydrate, 220 g of nickel nitrate hexahydrate, 254 g of cobalt nitrate hexahydrate, 20 g of manganese nitrate, 10 g of cerium nitrate hexahydrate, 5 g of chromium nitrate nonahydrate, and 5 g of potassium nitrate. Continue stirring until it is completely dissolved to obtain Material B, and keep the temperature of the material between 45 - 65°C. Add the prepared Material B to Material A at a feeding rate of 10 mL per minute. During the feeding process, keep the temperature at 75 - 85°C and continue uniform stirring until Materials A and B are mixed evenly to form a catalyst slurry. Then heat it to 90 - 95°C. After aging the mixed slurry at this temperature for about 30 - 60 minutes, perform spray forming on the slurry. First, preheat the temperature of the outlet air of the spray dryer to 160 - 180°C, then transport the above catalyst slurry to the top of the spray dryer at a feeding rate of 8 - 15 mL per minute. Under the condition of a rotary disk speed of 45 - 55 Hz, atomize and dry the slurry to form microsphere particles. Then place the spray-dried catalyst microsphere particles in a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing. First, calcine at 220 - 420°C for 1 hour to remove nitrogen, and then calcine at 550 - 650°C for 2 hours to obtain a fluidized bed catalyst.

[0085] Evaluate the abrasion rate of the fluidized bed catalyst prepared by the above method using the abrasion test method, and the abrasion index results are listed in Table 1.

[0086] Place the fluidized bed catalyst prepared by the above method in a fluidized bed reactor for evaluation. The evaluation conditions include: reaction temperature is 350°C, reaction pressure is 0.02 MPa, reaction gas raw material ratio: propylene / air = 1 / 9, and the final activity performance evaluation results are listed in Table 1.

[0087] Comparative Example 1 - 2

[0088] Refer to Comparative Example 1 - 1, the difference is that: the silica sol in the carrier liquid is replaced with a concentration of 50 wt%, and other preparation conditions are the same as those in Comparative Example 1 - 1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0089] Comparative Example 1 - 3

[0090] Referring to Comparative Example 1-1, the difference is that the silica sol in the carrier liquid is replaced with silica sol having a concentration of 30 wt%, and other preparation conditions are the same as those in Comparative Example 1-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 1.

[0091] Comparative Example 1-4

[0092] Referring to Comparative Example 1-1, the difference is that the aluminum sol in the carrier liquid is replaced with aluminum sol having a concentration of 30 wt%, and other preparation conditions are the same as those in Comparative Example 1-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 1.

[0093] Comparative Example 1-5

[0094] Referring to Comparative Example 1-1, the difference is that the aluminum sol in the carrier liquid is replaced with aluminum sol having a concentration of 15 wt%, and other preparation conditions are the same as those in Comparative Example 1-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 1.

[0095] Comparative Example 1-6

[0096] Referring to Comparative Example 1-1, the difference is that the carrier liquid is replaced with 800 g of silica sol having a concentration of 40 wt%, and other preparation conditions are the same as those in Comparative Example 1-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 1.

[0097] Example 4-1

[0098] S1. Prepare 500 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add 500 g of ammonium metavanadate in small amounts and multiple times, and continue stirring until completely dissolved to form an ammonium metavanadate solution. Keep it at a constant temperature of 45 - 65°C for standby. Then prepare another 150 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add 200 g of ferric nitrate nonahydrate, 140 g of bismuth nitrate pentahydrate, 220 g of nickel nitrate hexahydrate, 254 g of cobalt nitrate hexahydrate, 20 g of manganese nitrate, 10 g of cerium nitrate hexahydrate, 5 g of chromium nitrate nonahydrate, and 5 g of potassium nitrate in sequence. After continuous stirring until completely dissolved, add it to the ammonium metavanadate solution at a feeding rate of 10 mL per minute, and keep the temperature at 75 - 85°C and continue uniform stirring until evenly mixed to form an aqueous solution of the catalyst active component.

[0099] S2. Divide the prepared aqueous solution of the active component into two groups, A and B, with the same mass. Then prepare carrier liquid A-1, which includes 200 g of silica sol with a silica content of 50% and 200 g of alumina sol with an alumina content of 20%. Then, add the prepared silica sol and alumina sol to the aqueous solution of the active component in group A successively at a feeding rate of 10 mL per minute. During the feeding process, continuously stir at a constant speed to form a mixed slurry, and maintain the temperature range between 55 and 65 °C. Then heat it to 102 - 108 °C. After aging the mixed slurry at this temperature for about 10 - 20 minutes, finally form the catalyst core slurry, and store it at a temperature of 65 - 85 °C for standby.

[0100] S3 and S4. Start the spray dryer, preheat the temperature of the outlet air to 160 - 180 °C, and transport the above-mentioned catalyst precursor slurry to the top of the spray dryer at a feeding rate of 10 - 15 mL per minute. Under the condition of a rotating disk speed of 55 - 60 Hz, atomize and dry the slurry to form microsphere particles, that is, catalyst core particles, with a particle size distribution ≤ 45 microns. Put the spray-dried catalyst core particles into a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in a small amount of nitrogen flowing atmosphere. First, calcine at 220 - 420 °C for 1 hour to remove nitrogen, and then calcine at 550 - 650 °C for 2 hours to complete the forming preparation of the catalyst core microsphere particles.

[0101] S5. Then, prepare another 300 g of silica sol with a silica content of 30% and 100 g of nano gel, and uniformly mix them to form carrier liquid B-1. Then add the prepared carrier liquid B-1 to the aqueous solution of the active component in group B at a feeding rate of 10 mL per minute to form coating liquid C. Immediately add the catalyst core microsphere particles into coating liquid C at a feeding rate of about 5 g per minute. During the feeding process, use a high-shear disperser to continuously stir at a speed of 8000 rpm at a constant speed to form a mixed slurry, and maintain the temperature range between 55 and 65 °C. Then heat it to 102 - 108 °C. After aging the mixed slurry at this temperature for about 10 - 20 minutes, finally form a mixed suspension, and store it at a temperature of 65 - 85 °C for standby.

[0102] S6 and S7. Restart the spray dryer, preheat the temperature of the outlet air to 160 - 180 °C, and transport the mixed suspension to the top of the spray dryer at a feeding rate of 8 - 10 mL per minute. Under the condition that the rotating speed of the turntable is 45 - 50 Hz, atomize and dry the suspension to form spherical particles, namely the catalyst microspheres with a coated structure, and their average particle size is about 55 - 65 microns. Put the spray-dried catalyst microspheres into a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing. First, calcine at 220 - 420 °C for 1 hour to remove nitrogen, and then calcine at 550 - 650 °C for 2 hours to complete the forming preparation of the wear-resistant fluidized bed catalyst with a single-layer coated structure.

[0103] Evaluate the abrasion rate of the fluidized bed catalyst prepared in this example by using the above-mentioned abrasion test method. The test method is the same as that in Comparative Example 1, and the abrasion index results are listed in Table 1.

[0104] Place the fluidized bed catalyst prepared in this example in a fluidized bed reactor for evaluation. The evaluation conditions are the same as those in Comparative Example 1-1, and the performance evaluation results are listed in Table 1.

[0105] Example 4-2

[0106] Refer to Example 4-1, the difference is that: replace the carrier liquid A-1 in step S2 with 250 g of a silica sol with a silica content of 45% and 150 g of an alumina sol with an alumina content of 20%. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 1.

[0107] Example 4-3

[0108] Refer to Example 4-1, the difference is that: replace the carrier liquid A-1 in step S2 with 300 g of a silica sol with a silica content of 40% and 100 g of an alumina sol with an alumina content of 20%. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 1.

[0109] Example 4-4

[0110] Refer to Example 4-1, the difference is that: replace the carrier liquid B-1 in step S5 with 300 g of a silica sol with a silica content of 35% and 100 g of a nano gel. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 1.

[0111] Example 4-5

[0112] Referring to Example 4-1, the difference is that the carrier liquid B-1 in step S5 is replaced with 300 g of silica sol with a silica content of 25% and 100 g of nano-gel. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0113] Example 4-6

[0114] Referring to Example 4-1, the difference is that the aluminosilicate sol in the carrier liquid A-1 in step S2 is replaced with one having a concentration of 30 wt%. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0115] Example 4-7

[0116] Referring to Example 4-1, the difference is that the aluminosilicate sol in the carrier liquid A-1 in step S2 is replaced with one having a concentration of 15 wt%. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0117] Example 4-8

[0118] Referring to Example 4-1, the difference is that the carrier liquid B-1 in step S5 is replaced with 300 g of silica sol with a silica content of 30% and 100 g of nano-clay. Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0119] Example 4-9

[0120] Referring to Example 4-1, the difference is that the coating liquid C in step S5 of Example 4-1 is evenly divided into two groups C-1 and C-2 with the same mass. First, the catalyst core is added into the coating liquid C-1 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are carried out to obtain microsphere particles with a layer of coating, wherein the frequency of the atomization rotation speed is 48-49 Hz; then the microsphere particles with a layer of coating are added into the coating liquid C-2 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are repeated to obtain fluidized bed catalyst microsphere particles with a layer of coating, wherein the frequency of the atomization rotation speed is 45-47 Hz.

[0121] Other preparation conditions are the same as those in Example 4-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 1.

[0122] Example 4-10

[0123] Referring to Example 4-1, the difference is that: the coating liquid C in step S5 of Example 4-1 is evenly divided into three groups C-1, C-2 and C-3 with the same mass. First, the catalyst core microsphere particles are added into the coating liquid C-1 for mixing, and then high-shear dispersion, spray drying, calcination activation and other steps are carried out to obtain the microsphere particles with a single layer of coating, wherein the frequency of the atomization rotation speed is 48-49 Hz; then the microsphere particles with a single layer of coating are added into the coating liquid C-2 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are carried out again to obtain the microsphere particles with a double layer of coating, wherein the frequency of the atomization rotation speed is 46-47 Hz; then the microsphere particles with a double layer of coating are added into the coating liquid C-3 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are carried out again to obtain the fluidized bed catalyst microsphere particles with a triple layer of coating, wherein the frequency of the atomization rotation speed is 44-45 Hz.

[0124] Other preparation conditions are the same as those in Example 4-1, and the results of the attrition index and performance evaluation of the prepared catalyst products are listed in Table 1.

[0125] Table 1 Composition and evaluation results of fluidized bed catalysts applied to the production of acrolein / acrylic acid by propylene oxidation in Comparative Examples 1-1 to 1-6 and Examples 4-1 to 4-10

[0126]

[0127]

[0128] Note: In all examples in Table 1, the proportion of the active component is about 70 wt%, and the proportion of the carrier is about 30%.

[0129] As can be seen from Table 1, the fluidized bed catalyst with a coated structure has high abrasion resistance, and the activity of the catalyst with a coated structure is also high in the fluidized bed reaction for the production of acrolein / acrylic acid from propylene oxidation.

[0130] (2) The following uses Comparative Examples 2-1 to 2-8 and Examples 5-1 to 5-12 to illustrate the application of the wear-resistant fluidized bed catalyst provided by the present invention in the process of ammoxidation of propylene to acrylonitrile:

[0131] Comparative Example 2-1

[0132] Referring to the preparation methods of the catalysts for the ammoxidation of propylene to acrylonitrile described in Patents CN 201180024206.2, CN 200510046593.6 and CN 200810050797.0, the microsphere particle catalyst suitable for fluidized bed is prepared as follows:

[0133] Prepare 200 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add 200 g of ammonium metatungstate in small portions multiple times. Continue stirring until it is completely dissolved, then add 600 g of silica sol with a concentration of 40 wt% as the carrier liquid. After mixing evenly, prepare Material A and keep the temperature of the material between 45 - 65°C. Then prepare another 150 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add 70 g of ferric nitrate nonahydrate, 20 g of bismuth nitrate pentahydrate, 150 g of nickel nitrate hexahydrate, 50 g of magnesium nitrate hexahydrate, 50 g of cerium nitrate hexahydrate, 5 g of chromium nitrate nonahydrate, and 5 g of potassium nitrate in sequence. Continue stirring until it is completely dissolved to obtain Material B, and keep the temperature of the material between 45 - 65°C. Add the prepared Material B to Material A at a feeding rate of 10 mL per minute. During the feeding process, keep the temperature at 75 - 85°C and continue uniform stirring until Material A and Material B are mixed evenly to form a catalyst slurry. Then heat it to 90 - 95°C. Age the mixed slurry at this temperature for about 30 - 60 minutes, and then perform spray forming on the slurry. First, preheat the temperature of the air at the outlet of the spray dryer to 160 - 180°C, and then transport the above catalyst slurry to the top of the spray dryer at a feeding rate of 8 - 15 mL per minute. Under the condition of a rotary speed of 45 - 55 Hz of the turntable, atomize and dry the slurry to form microsphere particles. Then place the spray-dried catalyst microsphere particles in a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing. First, calcine at 220 - 420°C for 1 hour to remove nitrogen, and then calcine at 550 - 650°C for 2 hours to obtain a fluidized bed catalyst.

[0134] Evaluate the attrition rate of the fluidized bed catalyst prepared by the above method using the attrition test method, and the attrition index results are listed in Table 2.

[0135] Place the fluidized bed catalyst prepared by the above method in a fluidized bed reactor for evaluation. The evaluation conditions include: reaction temperature is 430°C, reaction pressure is 0.03 MPa, reaction gas raw material ratio: propylene / ammonia / air = 1 / 1.2 / 9.5, and the final activity performance evaluation results are listed in Table 2.

[0136] Comparative Example 2 - 2

[0137] Refer to Comparative Example 2 - 1. The difference is that the silica sol in the carrier liquid is replaced with a concentration of 50 wt%, and other preparation conditions are the same as those in Comparative Example 2 - 1. The attrition index results and performance evaluation results of the prepared catalyst product are listed in Table 2.

[0138] Comparative Example 2 - 3

[0139] Referring to Comparative Example 2-1, the difference is that the silica sol in the carrier liquid is replaced with silica sol having a concentration of 30 wt%, and other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0140] Comparative Example 2-4

[0141] Referring to Comparative Example 2-1, the difference is that the carrier liquid is replaced with a homogeneous mixture of 500 g of silica sol having a concentration of 40 wt% and 100 g of aluminum sol having a concentration of 20 wt%. Other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0142] Comparative Example 2-5

[0143] Referring to Comparative Example 2-1, the difference is that the carrier liquid is replaced with 400 g of silica sol having a concentration of 40 wt% and 200 g of aluminum sol having a concentration of 20 wt%. Other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0144] Comparative Example 2-6

[0145] Referring to Comparative Example 2-1, the difference is that the carrier liquid is replaced with 300 g of silica sol having a concentration of 40 wt% and 300 g of aluminum sol having a concentration of 20 wt%. Other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0146] Comparative Example 2-7

[0147] Referring to Comparative Example 2-1, the difference is that the carrier liquid is replaced with 500 g of silica sol having a concentration of 40 wt% and 100 g of aluminum sol having a concentration of 30 wt%. Other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0148] Comparative Example 2-8

[0149] Referring to Comparative Example 2-1, the difference is that except that the carrier liquid in Comparative Example 2-1 is replaced with 500 g of silica sol having a concentration of 40 wt% and 100 g of aluminum sol having a concentration of 15 wt%, other preparation conditions are the same as those in Comparative Example 2-1. The results of the attrition index and the performance evaluation of the prepared catalyst product are listed in Table 2.

[0150] Example 5-1

[0151] S1. Prepare 200 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, add ammonium metatungstate (200 g) in small amounts and multiple times. Continuously stir until it is completely dissolved to form an ammonium metatungstate solution, and keep it at a constant temperature of 45 - 65°C for standby. Then prepare another 150 mL of deionized water and heat it to 65 - 85°C. Under uniform stirring, sequentially add ferric nitrate nonahydrate (70 g), bismuth nitrate pentahydrate (20 g), nickel nitrate hexahydrate (150 g), magnesium nitrate hexahydrate (50 g), cerium nitrate hexahydrate (50 g), chromium nitrate nonahydrate (5 g), and potassium nitrate (5 g). Continuously stir until it is completely dissolved, then add it to the ammonium metatungstate solution at a feeding rate of 10 mL per minute, and keep the temperature at 75 - 85°C and continuously stir uniformly until it is mixed evenly to form an aqueous solution of the catalyst active component.

[0152] S2. Divide the above-prepared aqueous solution of the active component into two groups, A and B, with the same mass. Then prepare carrier liquid A - 1, which is mainly 300 g of silica sol with a silica content of 40 wt%. Add the prepared carrier liquid A - 1 to group A of the aqueous solution of the active component at a feeding rate of 10 mL per minute. Continuously stir uniformly during the feeding process to form a mixed slurry, and maintain the temperature range between 55 - 65°C. Then heat it to 102 - 108°C. Age the mixed slurry at this temperature for about 10 - 20 minutes, and finally form a catalyst core slurry, which is kept at a temperature of 65 - 85°C for standby.

[0153] S3 and S4. Start the spray dryer and preheat the temperature of the outlet air to 160 - 180°C. Feed the above catalyst core slurry to the top of the spray dryer at a feeding rate of 10 - 15 mL per minute. Under the condition of a rotary speed of the turntable of 55 - 60 Hz, atomize and dry the slurry to form microsphere particles, that is, catalyst core particles, with a particle size distribution ≤ 45 microns. Put the spray-dried catalyst core particles into a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing. First, calcine at 220 - 420°C for 1 hour to remove nitrogen, and then calcine at 550 - 650°C for 2 hours to complete the forming preparation of the catalyst core microsphere particles.

[0154] S5. Next, prepare another 250 g of silica sol with a silica content of 30 wt% and 50 g of nano-gel, and uniformly mix them to form carrier liquid B-1. Then, add the prepared carrier liquid B-1 to the aqueous solution of active components in Group B at a feeding rate of 10 mL per minute to form coating liquid C. Immediately afterwards, add the catalyst core microsphere particles into coating liquid C at a feeding rate of approximately 5 g / minute. During the feeding process, use a high-shear disperser to continuously stir at a rotation speed of 8000 rpm to form a mixed slurry, and maintain the temperature range between 55 and 65 °C. Then, heat it to 102 - 108 °C, age the mixed slurry at this temperature for about 10 - 20 minutes, and finally form a mixed suspension, which is stored at a temperature of 65 - 85 °C for standby.

[0155] S6 and S7. Start the spray dryer again, preheat the temperature of the outlet air to 160 - 180 °C, transport the mixed suspension to the top of the spray dryer at a feeding rate of 8 - 10 mL per minute. Under the condition of a rotary disk rotation speed of 45 - 50 Hz, atomize and dry the suspension to form spherical particles, namely the catalyst microspheres with a coated structure, whose average particle size is about 55 - 65 microns. Put the spray-dried catalyst microspheres into a rotary calcination furnace, rotate the furnace body at a rotation speed of 5 rpm in a small amount of nitrogen flowing atmosphere. First, calcine at 220 - 420 °C for 1 hour to remove nitrogen, and then calcine at 550 - 650 °C for 2 hours to complete the forming preparation of the single-layer coated structure catalyst. Finally, obtain the fluidized bed catalyst product of the present invention.

[0156] Evaluate the attrition rate of the fluidized bed catalyst prepared in this example using the above-mentioned attrition test method, and the test method is the same as that of Comparative Example 2-1. The attrition index results are listed in Table 2.

[0157] Place the fluidized bed catalyst prepared in this example in a fluidized bed reactor for evaluation. The evaluation conditions are the same as those of Comparative Example 2-1, and the performance evaluation results are listed in Table 2.

[0158] Example 5-2

[0159] Refer to Example 5-1, the difference is that: replace the carrier liquid A-1 in step S2 with silica sol with a silica content of 45 wt%, and the other preparation conditions are the same as those in Example 5-1. The attrition index results and performance evaluation results of the prepared catalyst product are listed in Table 2.

[0160] Example 5-3

[0161] Refer to Example 5-1, the difference is that: replace the carrier liquid A-1 in step S2 with silica sol with a silica content of 50 wt%, and the other preparation conditions are the same as those in Example 5-1. The attrition index results and performance evaluation results of the prepared catalyst product are listed in Table 2.

[0162] Example 5-4

[0163] Referring to Example 5-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 250 g of a silica sol with a silica content of 35 wt% and 50 g of a nanogel, and other preparation conditions are the same as those in Example 5-1. The abrasion index results and performance evaluation results of the obtained catalyst product are listed in Table 2.

[0164] Example 5-5

[0165] Referring to Example 5-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 250 g of a silica sol with a silica content of 25 wt% and 50 g of a nanogel, and other preparation conditions are the same as those in Example 5-1. The abrasion index results and performance evaluation results of the obtained catalyst product are listed in Table 2.

[0166] Example 5-6

[0167] Referring to Example 5-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 225 g of a silica sol with a silica content of 30 wt% and 75 g of a nanogel, and other preparation conditions are the same as those in Example 5-1. The abrasion index results and performance evaluation results of the obtained catalyst product are listed in Table 2.

[0168] Example 5-7

[0169] Referring to Example 5-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 250 g of a silica sol with a silica content of 30 wt% and 50 g of nanoclay, and other preparation conditions are the same as those in Example 5-1. The abrasion index results and performance evaluation results of the obtained catalyst product are listed in Table 2.

[0170] Example 5-8

[0171] Referring to Example 5-1, the difference is that: the coating liquid C in step S5 of Example 5-1 is evenly divided into two groups C-1 and C-2 with the same mass. First, the catalyst core microsphere particles are added to the coating liquid C-1 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are carried out to obtain microsphere particles with a single layer of coating, where the frequency of the atomization speed is 48 - 49 Hz; then the microsphere particles with a single layer of coating are added to the coating liquid C-2 for mixing, and high-shear dispersion, spray drying, calcination activation and other steps are repeated to obtain fluidized bed catalyst microsphere particles with a double layer of coating, where the frequency of the atomization speed is 45 - 47 Hz.

[0172] Other preparation conditions are the same as those in Example 5-1. The abrasion index results and performance evaluation results of the obtained catalyst product are listed in Table 2.

[0173] Examples 5 - 9

[0174] Reference Example 5 - 1, the difference is that: the coating liquid C in step S5 of Example 5 - 1 is evenly divided into three groups C - 1, C - 2, and C - 3 with the same mass. First, the catalyst core microsphere particles are added into the coating liquid C - 1 for mixing, and then subjected to high - shear dispersion, spray drying, calcination activation and other steps to obtain microsphere particles with a single - layer coating, where the frequency of the atomization speed is 48 - 49 Hz; then the microsphere particles with a single - layer coating are added into the coating liquid C - 2 for mixing, and again subjected to high - shear dispersion, spray drying, calcination activation and other steps to obtain microsphere particles with a double - layer coating, where the frequency of the atomization speed is 46 - 47 Hz; then the microsphere particles with a double - layer coating are added into the coating liquid C - 3 for mixing, and again subjected to high - shear dispersion, spray drying, calcination activation and other steps to obtain fluidized - bed catalyst microsphere particles with a triple - layer coating, where the frequency of the atomization speed is 44 - 45 Hz.

[0175] Other preparation conditions are the same as those in Example 5 - 1. The results of the attrition index and performance evaluation of the prepared catalyst products are listed in Table 2.

[0176] Example 5 - 10

[0177] Reference Example 5 - 1, the difference is that: the carrier liquid A - 1 in step S2 is replaced with 500 g of silica sol with a concentration of 40 wt% and 100 g of alumina sol with a concentration of 20 wt%, and the carrier liquid B - 1 in step S5 is replaced with 250 g of silica sol with a silica content of 30 wt% and 50 g of nano - gel. Other preparation conditions are the same as those in Example 5 - 1. The results of the attrition index and performance evaluation of the prepared catalyst products are listed in Table 2.

[0178] Example 5 - 11

[0179] Reference Example 5 - 1, the difference is that: the carrier liquid A - 1 in step S2 is replaced with 500 g of silica sol with a concentration of 40 wt% and 100 g of alumina sol with a concentration of 20 wt%, and the carrier liquid B - 1 in step S5 is replaced with 250 g of silica sol with a silica content of 30 wt% and 50 g of nano - gel.

[0180] In addition, the coating liquid C in step S5 of Example 5-1 was evenly divided into two groups C-1 and C-2 with the same mass. First, the catalyst core microsphere particles were added into the coating liquid C-1 and mixed, and then steps such as high-shear dispersion, spray drying, and calcination activation were carried out to obtain microsphere particles with a single layer of coating, where the frequency of the atomization rotation speed was 48 - 49 Hz. Then, the microsphere particles with a single layer of coating were added into the coating liquid C-2 and mixed, and the steps of high-shear dispersion, spray drying, and calcination activation were repeated to obtain fluidized bed catalyst microsphere particles with a double layer of coating, where the frequency of the atomization rotation speed was 45 - 47 Hz.

[0181] Other preparation conditions were the same as those in Example 5-1, and the results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 2.

[0182] Example 5-12

[0183] Referring to Example 5-1, the difference lies in that: the carrier liquid A-1 in step S2 was replaced with 500 g of silica sol with a concentration of 40 wt% and 100 g of alumina sol with a concentration of 20 wt%, and the carrier liquid B-1 in step S5 was replaced with 250 g of silica sol with a silica content of 30 wt% and 50 g of nano gel.

[0184] The coating liquid C in step S5 of Example 5-1 was evenly divided into three groups C-1, C-2, and C-3 with the same mass. First, the catalyst core microsphere particles were added into the coating liquid C-1 and mixed, and then steps such as high-shear dispersion, spray drying, and calcination activation were carried out to obtain microsphere particles with a single layer of coating, where the frequency of the atomization rotation speed was 48 - 49 Hz. Then, the microsphere particles with a single layer of coating were added into the coating liquid C-2 and mixed, and the steps of high-shear dispersion, spray drying, and calcination activation were carried out again to obtain microsphere particles with a double layer of coating, where the frequency of the atomization rotation speed was 46 - 47 Hz. Then, the microsphere particles with a double layer of coating were added into the coating liquid C-3 and mixed, and the steps of high-shear dispersion, spray drying, and calcination activation were carried out again to obtain fluidized bed catalyst microsphere particles with a triple layer of coating, where the frequency of the atomization rotation speed was 44 - 45 Hz.

[0185] Other preparation conditions were the same as those in Example 5-1, and the results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 2.

[0186] Table 2 Composition and evaluation results of fluidized bed catalysts applied to the ammoxidation of propylene to acrylonitrile in Comparative Examples 2-1 - 2-8 and Examples 5-1 - 5-12

[0187]

[0188]

[0189]

[0190] Note: In all the examples in Table 2, the proportion of the active component is about 60 wt%, and the proportion of the carrier is about 40%.

[0191] As can be seen from Table 2, the fluidized bed catalyst with a coated structure exhibits high abrasion resistance, and the activity of the catalyst with a coated structure is also relatively high in the ammoxidation fluidized bed reaction of propylene.

[0192] (III) The following uses Comparative Examples 3-1 to 3-6 and Examples 6-1 to 6-12 to illustrate the application of the abrasion-resistant fluidized bed catalyst provided by the present invention in the process of preparing propylene oxide by epoxidation of propylene. It should be noted that for propylene and H 2 O 2 For the fluidized bed catalyst used in gas-phase epoxidation, alumina or alumina-containing additives cannot be used during its forming process, and only silica-containing additives can be used. The specific embodiments are as follows:

[0193] Comparative Example 3-1

[0194] Referring to the preparation methods of titanium-silicon catalysts for preparing propylene oxide by epoxidation of propylene described in Patent CN 201310102318.6, CN 200910067853.6 and CN 202411170462.8, a microsphere particle catalyst suitable for fluidized bed is prepared as follows:

[0195] Prepare 700 mL of deionized water, and add 300 g of silica sol with a concentration of 30 wt% in small amounts and multiple times under uniform stirring. After mixing evenly for 1 hour, material A is formed. Then prepare another 300 g of commercially available titanium-silicate molecular sieve raw powder as material B. Add material B to material A in small amounts and multiple times, and keep stirring uniformly during the adding process until material A and material B are mixed evenly to form a catalyst slurry. Then perform spray forming on the slurry. First, preheat the temperature of the outlet air of the spray dryer to 140 - 160 °C, and then transport the above catalyst slurry to the top of the spray dryer at a feeding rate of 8 - 15 mL per minute. Under the condition of a rotary speed of 45 - 55 Hz of the turntable, atomize and dry the slurry to form microsphere particles. Then place the spray-dried catalyst microsphere particles in a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing, and calcine at 520 - 590 °C for 2 hours to obtain a fluidized bed catalyst.

[0196] The fluidized bed catalyst prepared by the above method for preparing propylene oxide is evaluated for its abrasion rate by using an abrasion test method, and the results of its abrasion index are listed in Table 3.

[0197] The propylene oxide fluidized bed catalyst prepared by the above method was placed in a fluidized bed reactor for evaluation. The evaluation conditions included: the reaction temperature was 155 °C, the reaction pressure was 0.01 MPa, and the reaction gas raw material ratio: propylene / H 2 O 2 = 1 / 0.2. The final performance evaluation results are listed in Table 3.

[0198] Comparative Example 3-2

[0199] Referring to Comparative Example 3-1, the difference is that: the silica sol in the material A is replaced with a silica sol having a concentration of 40 wt%, and other preparation conditions are the same as those in Comparative Example 3-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 3.

[0200] Comparative Example 3-3

[0201] Referring to Comparative Example 3-1, the difference is that: the silica sol in the material A is replaced with a silica sol having a concentration of 50 wt%, and other preparation conditions are the same as those in Comparative Example 3-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 3.

[0202] Comparative Example 3-4

[0203] Referring to Comparative Example 3-1, the difference is that: 600 mL of deionized water was prepared and mixed and stirred evenly with 250 g of tetrapropylammonium hydroxide (TPAOH) to form a dilution solution. Then, 400 g of tetraethyl orthosilicate (TEOS) was added to the dilution solution as a silicon source, and stirring was continued for 2 hours to obtain TEOS basic hydrolyzate as material A. Then, another 300 g of commercially available titanium silicalite zeolite powder was prepared as material B. Material B was added to material A in small amounts and multiple times, and the addition process was continuously stirred evenly until material A and material B were mixed evenly to form a catalyst slurry.

[0204] Other preparation conditions are the same as those in Comparative Example 3-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 3.

[0205] Comparative Example 3-5

[0206] Referring to Comparative Example 3-4, the difference is that: the addition amount of tetraethyl orthosilicate in the material A is changed to 500 g, and other preparation conditions are the same as those in Comparative Example 3-1. The abrasion index results and performance evaluation results of the prepared catalyst product are listed in Table 3.

[0207] Comparative Example 3-6

[0208] Referring to Comparative Examples 3-4, the difference lies in that: the dosage of tetraethyl orthosilicate in the material A is changed to 600 g, and other preparation conditions are the same as those in Comparative Example 3-1. The attrition index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0209] Example 6-1

[0210] S1. Prepare 700 mL of deionized water, and add 300 g of commercially available titanium-silica molecular sieve raw powder in small amounts and multiple times under uniform stirring. The addition process continues with uniform stirring until it is evenly mixed to form an active component slurry.

[0211] S2. Divide the active component slurry into two groups, A and B, with the same mass. Then prepare 150 g of silica sol with a silica content of 40 wt% as carrier liquid A-1. Then add the prepared carrier liquid A-1 to the aqueous solution of the active component in group A at a feeding rate of 10 mL per minute. During the addition process, continuous uniform stirring is carried out to finally form a catalyst core slurry.

[0212] S3 and S4. Start the spray dryer, preheat the temperature of the outlet air to 140-160 °C, and transport the above-mentioned catalyst core slurry to the top of the spray dryer at a feeding rate of 10-15 mL per minute. Under the condition of a rotary speed of 55-60 Hz of the turntable, the slurry is atomized and dried to form microsphere particles, that is, catalyst core particles, with a particle size distribution ≤ 45 microns. Put the spray-dried catalyst core particles into a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing, and calcine at 500-540 °C for 2 hours to complete the forming preparation of the catalyst core microsphere particles.

[0213] S5. Then prepare another 150 g of silica sol with a silica content of 30 wt% and 50 g of nano-gel, and mix them evenly to form carrier liquid B-1. Then add the prepared carrier liquid B-1 to the aqueous solution of the active component in group B at a feeding rate of 10 mL per minute to form coating liquid C. Immediately add the catalyst core microsphere particles into coating liquid C at a feeding rate of about 5 g / minute. During the addition process, use a high-shear disperser to continuously stir evenly at a speed of 8000 rpm to form a mixed slurry.

[0214] S6 and S7. Start the spray dryer again, preheat the temperature of the outlet air to 140 - 150 °C, and convey the mixed suspension to the top of the spray dryer at a feeding rate of 8 - 10 mL per minute. Under the condition that the rotating speed of the turntable is 45 - 50 Hz, atomize and dry the suspension to form spherical particles, namely the catalyst microspheres with a coated structure, and their average particle size is about 60 - 65 microns. Put the spray-dried catalyst microspheres into a rotary calcination furnace, rotate the furnace body at a speed of 5 rpm in an atmosphere with a small amount of nitrogen flowing, and calcine at 550 - 590 °C for 2 hours to complete the forming preparation of the monolayer-coated structure catalyst. Finally, obtain the fluidized bed catalyst product of the present invention.

[0215] Evaluate the attrition rate of the fluidized bed catalyst prepared in this example by using the above-mentioned attrition test method. The test method is the same as that of Comparative Example 3-1, and the results of its attrition index are listed in Table 3.

[0216] Place the fluidized bed catalyst prepared in this example in a fluidized bed reactor for evaluation. The evaluation conditions are the same as those of Comparative Example 3-1, and the results of its performance evaluation are listed in Table 3.

[0217] Example 6-2

[0218] Refer to Example 6-1, the difference is that: except that the carrier liquid A-1 in step S2 is replaced with a silica sol with a silica content of 45%, other preparation conditions are the same as those in Example 6-1. The results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 3.

[0219] Example 6-3

[0220] Refer to Example 6-1, the difference is that: except that the carrier liquid A-1 in step S2 is replaced with a silica sol with a silica content of 50%, other preparation conditions are the same as those in Example 6-1. The results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 3.

[0221] Example 6-4

[0222] Refer to Example 6-1, the difference is that: except that the carrier liquid B-1 in step S5 is replaced with a silica sol with a silica content of 35 wt%, other preparation conditions are the same as those in Example 6-1. The results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 3.

[0223] Example 6-5

[0224] Refer to Example 6-1, the difference is that: except that the carrier liquid B-1 in step S5 is replaced with a silica sol with a silica content of 25 wt%, other preparation conditions are the same as those in Example 6-1. The results of the attrition index and performance evaluation of the prepared catalyst product are listed in Table 3.

[0225] Example 6-6

[0226] Referring to Reference Example 6-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 100 g of silica sol with a silica content of 30 wt% and 50 g of nano gel. Other preparation conditions are the same as those in Example 6-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0227] Example 6-7

[0228] Referring to Reference Example 6-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 125 g of silica sol with a silica content of 30 wt% and 25 g of nano gel. Other preparation conditions are the same as those in Example 6-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0229] Example 6-8

[0230] Referring to Reference Example 6-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 140 g of silica sol with a silica content of 30 wt% and 10 g of nano gel. Other preparation conditions are the same as those in Example 6-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0231] Example 6-9

[0232] Referring to Reference Example 6-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 145 g of silica sol with a silica content of 30 wt% and 5 g of nano gel. Other preparation conditions are the same as those in Example 6-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0233] Example 6-10

[0234] Referring to Reference Example 6-1, the difference is that: the carrier liquid B-1 in step S5 is replaced with 145 g of silica sol with a silica content of 30 wt% and 5 g of nano clay. Other preparation conditions are the same as those in Example 6-1. The abrasion index results and performance evaluation results of the prepared catalyst products are listed in Table 3.

[0235] Example 6-11

[0236] Referring to Comparative Example 6-1, the difference is as follows: The coating liquid C in step S5 is evenly divided into two groups C-1 and C-2 with the same mass. First, the catalyst core microsphere particles are added to the coating liquid C-1 for mixing, and then high-shear dispersion, spray drying, calcination activation and other steps are carried out to obtain the microsphere particles with a single-layer coating, wherein the frequency of the atomization rotation speed is 48-49 Hz; then the microsphere particles with a single-layer coating are added to the coating liquid C-2 for mixing, and the high-shear dispersion, spray drying, calcination activation and other steps are repeated to obtain the fluidized bed catalyst microsphere particles with a double-layer coating, wherein the frequency of the atomization rotation speed is 45-47 Hz.

[0237] Other preparation conditions are the same as those in Example 6-1, and the results of the attrition index and performance evaluation of the prepared catalyst products are listed in Table 3.

[0238] Example 3-12

[0239] Referring to Comparative Example 6-1, the difference is as follows: The coating liquid C in step S5 is evenly divided into three groups C-1, C-2 and C-3 with the same mass. First, the catalyst core microsphere particles are added to the coating liquid C-1 for mixing, and then high-shear dispersion, spray drying, calcination activation and other steps are carried out to obtain the microsphere particles with a single-layer coating, wherein the frequency of the atomization rotation speed is 48-49 Hz; then the microsphere particles with a single-layer coating are added to the coating liquid C-2 for mixing, and the high-shear dispersion, spray drying, calcination activation and other steps are carried out again to obtain the microsphere particles with a double-layer coating, wherein the frequency of the atomization rotation speed is 46-47 Hz; then the microsphere particles with a double-layer coating are added to the coating liquid C-3 for mixing, and the high-shear dispersion, spray drying, calcination activation and other steps are carried out again to obtain the fluidized bed catalyst microsphere particles with a triple-layer coating, wherein the frequency of the atomization rotation speed is 44-45 Hz.

[0240] Other preparation conditions are the same as those in Example 6-1, and the results of the attrition index and performance evaluation of the prepared catalyst products are listed in Table 3.

[0241] Table 3 Composition and evaluation results of the fluidized bed catalysts applied to the epoxidation of propylene to propylene oxide in Comparative Examples 3-1 to 3-6 and Examples 6-1 to 6-12

[0242]

[0243]

[0244] It can be seen from Table 3 that the fluidized bed catalyst with a coated structure exhibits high abrasion resistance, and the activity of the catalyst with a coated structure also remains in a relatively high range in the fluidized bed reaction of propylene epoxidation.

[0245] The ideal embodiments of the present invention provide inspiration. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of this invention.

[0246] The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A wear-resistant fluidized bed catalyst, characterized in that: include: A catalyst core and a coating layer covering the catalyst core, wherein the coating layer is at least one layer; The core and the coating layer both include active components, carriers and carrier additives; The carrier is silica sol; The carrier additive of the core is an aluminum compound, and the carrier additive of the coating layer is a nano binder.

2. The wear-resistant fluidized bed catalyst according to claim 1, characterized in that: The aluminum-containing compound is one of aluminum sol, pseudo-boehmite, aluminum oxide, aluminum nitrate, aluminum hydroxide, and aluminum phosphate.

3. The wear-resistant fluidized bed catalyst according to claim 1, characterized in that: The carrier included in the core is high-particle silica sol, and the carrier included in the coating layer is low-particle silica sol; The content of silicon dioxide in the high-particle silica sol is 40-50%; The average particle size of the high-granularity silica sol is ≥20nm, and the specific surface area is 100-150m 2 / g, viscosity is 8-15cp (@25℃), pH is 8-10; The content of silicon dioxide in the low-particle silica sol is 25-35%; The low-particle silica sol has an average particle size of 12 to 20 nm and a specific surface area of ​​200 to 250 m 2 / g, viscosity ≤22cp (@25℃), pH value is 8-10.

4. The wear-resistant fluidized bed catalyst according to any one of claims 1 to 3, characterized in that: The coating layer has a thickness of 10 to 60 micrometers; and / or, The size of the nano binder is 1 to 100 nm; and / or, The nano binder is one of nano gel, nano clay and nano carbon fiber tube.

5. A method for preparing a wear-resistant fluidized bed catalyst, characterized in that: Used to prepare the wear-resistant fluidized bed catalyst according to any one of claims 1 to 4, comprising: a catalyst core molding step and a catalyst coating molding step; The catalyst core forming step comprises: First, the active component, the silica sol and the aluminum-containing compound are prepared into a mixed slurry in a certain proportion, and then dried and sprayed to form microsphere particles, and then calcined and activated to obtain the catalyst core; The catalyst coating molding step comprises: The active component, the silica sol and the nano binder are prepared into a coating layer slurry in a certain ratio, and then mixed with the catalyst core so that the surface of the catalyst core is evenly coated with the coating layer slurry to form a mixed suspension; The mixed suspension is spray-dried, calcined and activated in sequence to obtain the wear-resistant fluidized bed catalyst; The catalyst coating molding step is repeated multiple times to obtain a wear-resistant fluidized bed catalyst with a multi-layer coating structure.

6. The method for preparing the wear-resistant fluidized bed catalyst according to claim 5, characterized in that: In the catalyst core forming step, the specific preparation steps of the mixed slurry include: Add compounds containing specific metal elements into deionized water in a certain proportion and order to dissolve them, forming an active component aqueous solution, and keep it warm for later use; A certain amount of the active component aqueous solution is then taken, and high-particle silica sol and the aluminum-containing compound are added in sequence for mixing, and continuously stirred under certain heating temperature conditions to form a uniform slurry liquid, which is then aged to obtain the mixed slurry.

7. The method for preparing the wear-resistant fluidized bed catalyst according to claim 6, characterized in that: The temperature of the deionized water containing the specific metal element is 55-85° C. The heating temperature is 55 to 70°C, and the stirring time is 25 to 60 minutes; The aging temperature is 95-110° C., the time is 10-30 minutes, and the slurry liquid is continuously stirred during the aging process.

8. The method for preparing the wear-resistant fluidized bed catalyst according to claim 6, characterized in that: In the catalyst coating molding step, the specific preparation steps of the coating layer slurry are: A certain amount of the active component aqueous solution prepared in the catalyst core molding step is taken, and low-particle silica sol and nano binder are added in a certain proportion and mixed evenly to obtain the coating layer slurry.

9. The method for preparing the wear-resistant fluidized bed catalyst according to claim 5, characterized in that: In the catalyst core molding step and the catalyst coating molding step, the calcination activation temperature is 550-650° C. and the time is 2-4 hours.

10. An application of a wear-resistant fluidized bed catalyst, characterized in that: The wear-resistant fluidized bed catalyst described in any one of claims 1 to 4, or the wear-resistant fluidized bed catalyst prepared by the preparation method of claims 5 to 9, is applied to a fluidized bed reaction process.

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