Fluidized bed catalysts, processes for their preparation and use, and processes for the catalytic conversion of dimethyl ether to olefins / aromatics

Abstract

The present application relates to the field of catalyst, specifically relates to a kind of fluidized bed catalyst and its preparation method and application and the method for catalyzing dimethyl ether to be olefin / aromatic hydrocarbon, the catalyst contains: A 90-99.5% molecular sieve carrier by weight fraction;B 0.5-10% active metal oxide;The proportion of the number of composite acid formed by active metal oxide and molecular sieve to the total acid number of catalyst is 10-80%.The catalyst of the present application has good stability, high activity, high aromatic hydrocarbon and olefin selectivity when used for aromatic hydrocarbon and olefin production.

Description

Technical Field

[0001] This invention relates to a fluidized bed catalyst, its preparation method and application, and a method for catalytically producing olefins / aromatics from dimethyl ether. Background Technology

[0002] Aromatics and olefins are among the most important basic petrochemical products, widely used in various fields of production and daily life. In recent years, with the continuous development of related chemical industries, the global demand for olefins and aromatics has continued to grow.

[0003] The conversion of oxygen-containing compounds produced downstream of coal chemical, natural gas, and biomass chemical industries, as well as abundant and inexpensive low-carbon hydrocarbon components from petrochemicals, into high-value-added aromatics and olefins has become a significant research focus in recent years. Commonly used processes in aromatics and olefin production include fixed-bed, moving-bed, and fluidized-bed processes. While fixed-bed processes are relatively simple, they often suffer from catalyst deactivation, requiring frequent reaction / regeneration switching, complex operation, difficulty in heat removal, and high demands on catalyst coking inhibition performance, resulting in relatively small-scale production. Fluidized-bed processes, on the other hand, offer advantages such as uniform temperature distribution within the reactor, convenient heat removal, continuous catalyst regeneration, and ease of large-scale production, making them widely applicable in aromatics and olefin production.

[0004] CN105268470A discloses a fluidized bed catalyst for the conversion of coal-based / bio-based oxygen-containing compounds, its preparation, and its application. The catalyst's composition, by mass percentage, is: 30-70 wt% rare earth ZSM-11 molecular sieve, 0.5-5.0 wt% P2O5, 0.5-4.0 wt% ZnO, with the balance being a binder. The binder is a mixture of alumina and clay in a certain proportion, wherein alumina accounts for 15-30 wt% of the catalyst mass, and clay accounts for 14-40 wt% of the catalyst mass. The catalyst is prepared by uniformly mixing the above components or their precursors with water, followed by spray molding and calcination. This catalyst is used for the conversion of coal-based / bio-based oxygen-containing compounds, or mixtures thereof with hydrocarbon components, to produce automotive fuels / aromatic chemicals. It features high feed conversion rate and liquid product yield, good catalyst anti-wear performance, and excellent hydrothermal stability.

[0005] CN103007985A discloses a catalyst for converting alcohols and ethers into aromatics, and its preparation and use methods. First, a hydrogen-form nano-sized ZSM-5 molecular sieve is prepared using a template agent, kaolin, sodium hydroxide, and water as raw materials, and then directly prepared into the catalyst. Alternatively, a two-, three-, or four-component catalyst containing metals and / or structural reinforcing agents and / or stabilizing agents is prepared based on the hydrogen-form nano-sized ZSM-5 molecular sieve. The catalyst comprises the following components by mass fraction: 30-100% needle-like nano-ZSM-5 molecular sieve, 0-10% metal, 0-50% structural reinforcing agent, and 0-10% stabilizing agent.

[0006] Fluidized bed catalysts for the production of aromatics and olefins typically require a combination of metal oxides and molecular sieves. The resulting complex forms new acidic sites, which are the primary active centers for aromatics and olefin production. Therefore, the proportion of the complex acid formed by the metal oxide and molecular sieve combination is a key indicator. On the other hand, fluidized bed processes require continuous cyclic regeneration of the catalyst, placing high demands on its flowability and wear resistance. The catalyst needs high mechanical strength and surface smoothness, necessitating optimization of the preparation method to meet these requirements. Furthermore, catalysts often include stabilizing agents for the framework and modifiers to regulate product composition. These components have vastly different precursor properties, which can easily interfere with each other during preparation, even leading to performance degradation. Summary of the Invention

[0007] The purpose of this invention is to provide a fluidized bed catalyst with good stability and high activity.

[0008] Existing literature reports on the preparation of fluidized bed catalysts and their preparation methods all have problems such as complex composition, simultaneous addition of multiple components, mutual interference of functions, low proportion of composite acid, and poor strength and wear resistance of single spray drying molding.

[0009] The purpose of this invention is to overcome the problems of complex composition, simultaneous addition of multiple components, mutual interference of functions, low proportion of composite acid, and poor strength and wear resistance of single spray drying in the existing technology, and to provide a fluidized bed catalyst with good stability and high activity.

[0010] To achieve the above objectives, the first aspect of the present invention provides a fluidized bed catalyst, which, by weight fraction, contains: A 90-99.5% molecular sieve support; B 0.5-10% active metal oxide; and the amount of the composite acid formed by the combination of active metal oxide and molecular sieve accounts for 10-80% of the total amount of acid in the catalyst.

[0011] The second aspect of the present invention provides a method for preparing the fluidized bed catalyst of the present invention, the method comprising: (1) mixing molecular sieve, binder, optionally matrix, framework stabilizer and water, stirring evenly, and then subjecting the mixture to a first spray drying and a first calcination to obtain a molecular sieve support;

[0012] (2) The molecular sieve support, the metal oxide precursor and water are mixed and stirred evenly, and then spray-dried and calcined to obtain a fluidized bed catalyst.

[0013] A third aspect of the present invention provides the application of the fluidized bed catalyst described herein in the production processes of aromatics and olefins.

[0014] A fourth aspect of the present invention provides a method for catalytically producing olefins / aromatics from dimethyl ether, the method comprising: contacting dimethyl ether with a catalyst in a fluidized bed reactor, wherein the catalyst is the fluidized bed catalyst described in the present invention.

[0015] The method of this invention utilizes a two-stage spray drying process to form a fluidized bed catalyst. The first stage forms a molecular sieve support, and the second stage modifies the catalyst, resulting in better dispersion of the supported components and increasing the number of acidic sites in the metal oxide-molecular sieve composite. This avoids the inhomogeneity issues associated with conventional impregnation modification methods. Compared to the one-pot spray drying method, this method avoids interference between modifying elements, improves catalyst strength, reduces wear rate, and enhances stability in fluidized bed reactors. The catalyst of this invention achieves a composite acid content of 10-80% of the total catalyst acid content when the metal oxide loading is 0.5-10%, with a catalyst-molecular sieve support wear rate ratio of 0.30-0.95.

[0016] The fluidized bed catalyst of this invention utilizes a functional combination of metal oxides and molecular sieve supports to form a fluidized bed catalyst, offering advantages such as strong raw material adaptability and tunable products. By controlling the dispersion of the supported metal oxide component, the composite oxide formed by the metal oxide and molecular sieve has a higher proportion of acidic sites, thereby improving the utilization efficiency of the supported component and the number of effective active centers. By controlling the wear rate ratio of the fluidized bed catalyst to the molecular sieve support within a low range, the catalyst strength is improved and wear is reduced.

[0017] The catalyst of this invention has the advantages of good stability, high activity, and high selectivity for aromatics and olefins when used in the production of aromatics and olefins. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] In this invention, the number of composite acids formed by the combination of metal oxide and molecular sieve refers to the number of acidic sites in the composite oxide formed by the combination of metal oxide and molecular sieve.

[0020] In this invention, the total acid number of the catalyst refers to the total number of all acidic sites possessed by the catalyst.

[0021] In this invention, the wear rate refers to the ratio of the worn mass to the initial mass per unit time, expressed as a percentage.

[0022] This invention provides a fluidized bed catalyst, which, by weight fraction, contains:

[0023] A 90-99.5% molecular sieve carrier;

[0024] B 0.5-10% of active metal oxides, for example 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%;

[0025] The proportion of the composite acid formed by the combination of active metal oxide and molecular sieve to the total acid content of the catalyst is 10-80%, for example, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, and 80%. When used in the production of aromatics and olefins, the catalyst of this invention has advantages such as good stability, high activity, and high selectivity for aromatics and olefins.

[0026] According to a preferred embodiment of the present invention, the wear rate ratio of the fluidized bed catalyst to the molecular sieve support is 0.30-0.95, for example, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95; preferably 0.40-0.95, and more preferably 0.45-0.90. By employing the aforementioned preferred embodiment, the goal of reducing the wear rate of the fluidized bed catalyst can be achieved.

[0027] According to a preferred embodiment of the present invention, the amount of the composite acid formed by the combination of metal oxide and molecular sieve accounts for 11-70% of the total amount of acid in the catalyst, preferably 12-66%. The aforementioned preferred embodiment enables effective control of the ratio of metal oxide / molecular sieve composite acid, thereby improving the selectivity of target olefins and aromatic products.

[0028] According to a particularly preferred embodiment of the present invention, the catalyst contains the following components: 92-99.5% molecular sieve support and 0.5-8% metal oxide.

[0029] According to a particularly preferred embodiment of the present invention, the catalyst contains the following components in the following proportions: 95-99.5% molecular sieve support and 0.5-5% metal oxide.

[0030] This invention provides a fluidized bed catalyst for the production of aromatics and olefins. The catalyst, by weight fraction, contains the following components: 90-99.5% molecular sieve support and 0.5-10% metal oxide. The catalyst also has the following characteristics: with a metal oxide loading of 0.5-10%, the proportion of the composite acid formed by the combination of metal oxide and molecular sieve to the total acid content of the catalyst is 10-80%; and the attrition ratio of the fluidized bed catalyst to the molecular sieve support is 0.30-0.95.

[0031] According to a particularly preferred embodiment of the present invention, the catalyst has the following characteristics: when the metal oxide loading is 0.5-10%, the amount of composite acid formed by the combination of metal oxide and molecular sieve accounts for 11-70% of the total amount of acid in the catalyst; and the wear ratio of the fluidized bed catalyst to the molecular sieve support is 0.40-0.95.

[0032] According to a particularly preferred embodiment of the present invention, the catalyst has the following characteristics: when the metal oxide loading is 0.6-5%, the amount of composite acid formed by the combination of metal oxide and molecular sieve accounts for 12-55% of the total amount of acid in the catalyst; and the wear ratio of the fluidized bed catalyst to the molecular sieve support is 0.45-0.90.

[0033] In this invention, the range of molecular sieve types is relatively wide. For this invention, it is preferred that the molecular sieve be selected from at least one of eight-membered rings, ten-membered rings and twelve-membered rings in its structure, and the acid content is 0.05-2.8 mmol / g. Preferably, the molecular sieve is selected from one or more of the structural types CHA, MWW, MFI, BEA, MOR and FAU.

[0034] In this invention, the range of types of active metals that can be selected is relatively wide. For this invention, it is preferred that the active metals be selected from one or more of magnesium, calcium, barium, chromium, molybdenum, manganese, nickel, copper, zinc, gallium and silver.

[0035] Catalysts possessing the aforementioned characteristics of this invention can all achieve the objectives of this invention, and there are no special requirements for their preparation methods. To further illustrate the feasibility of the catalyst of this invention, this invention provides a method for preparing the fluidized bed catalyst described in this invention, the method comprising:

[0036] (1) Molecular sieve, binder, optional matrix, skeleton stabilizer and water are mixed and stirred evenly, and then the mixture is spray-dried and calcined to obtain molecular sieve carrier;

[0037] (2) The molecular sieve support, the metal oxide precursor, and water are mixed and stirred evenly, then subjected to a second spray drying and a second calcination to obtain a fluidized bed catalyst. The fluidized bed catalyst preparation method provided by this invention is characterized by employing a two-stage spray drying process. The first stage forms the molecular sieve support, and the second stage modifies the fluidized bed catalyst. This method has the advantage of improving the dispersion of the supported components, enabling more effective composite formation between the metal oxide and the molecular sieve, increasing the utilization efficiency of the supported components and the number of effective active centers, and resulting in a catalyst with better stability during the production of aromatics and olefins. Furthermore, by adding a framework stabilizing agent during the first stage of molecular sieve support preparation and adding a metal oxide during the second stage of modification, the unevenness of conventional impregnation modification methods is avoided, reducing mutual interference between modifying elements. The second spray drying also improves the strength of the catalyst particles and reduces the wear rate.

[0038] In this invention, the conditions for the first spray drying and the second spray drying have a wide range of options and can be adjusted as needed.

[0039] According to a preferred embodiment of the present invention, the conditions for the first spray drying include: a temperature of 130-250°C, for example, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C; and a pressure of 0.1-1.3 MPa.

[0040] According to a preferred embodiment of the present invention, the conditions for the second spray drying include: a temperature of 110-210°C, for example, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 175°C, 180°C, 185°C, 190°C, 200°C, 205°C, or 210°C; and a pressure of 0.1-1.3 MPa.

[0041] According to a preferred embodiment of the present invention, preferably, the temperature of the first spray drying is 20-50°C higher than the temperature of the second spray drying, for example, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, or 50°C. This can further improve the dispersion of the loaded metal oxide component.

[0042] In this invention, the conditions for the first and second roasting can be conventional conditions, and the temperature and time can be determined as needed.

[0043] According to a preferred embodiment of the present invention, the conditions for the first roasting include: a temperature of 520-750°C, for example, 520°C, 525°C, 530°C, 535°C, 540°C, 545°C, 550°C, 555°C, 560°C, 565°C, 570°C, 575°C, 580°C, 585°C, 590°C, 595°C, 600°C, 605°C, 610°C, 615°C, 620°C, 625°C, 630°C, 635°C, 640°C, 645°C, 650°C, 65°C. 5℃, 660℃, 665℃, 670℃, 675℃, 680℃, 685℃, 690℃, 695℃, 700℃, 705℃, 710℃, 715℃, 720℃, 725℃, 730℃, 735℃, 740℃, 745℃, 750℃; the roasting time can be adjusted according to specific needs. For this invention, the preferred first roasting time is 2-10 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours.

[0044] According to a preferred embodiment of the present invention, the conditions for the second calcination include: a temperature of 350-620°C, for example, 350°C, 355°C, 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C, 400°C, 405°C, 410°C, 415°C, 420°C, 425°C, 430°C, 435°C, 440°C, 445°C, 450°C, 455°C, 460°C, 465°C, 470°C, 475°C, 480°C, 485°C, 490°C, 495°C, 500°C, 505°C, 510°C, 515°C, 520°C, 525°C, 53°C, etc. 0℃, 535℃, 540℃, 545℃, 550℃, 555℃, 560℃, 565℃, 570℃, 575℃, 580℃, 585℃, 590℃, 595℃, 600℃, 605℃, 610℃, 615℃, 620℃; the roasting time can be adjusted according to specific needs. For this invention, the preferred second roasting time is 2-20 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours.

[0045] According to a preferred embodiment of the present invention, preferably, the temperature of the first calcination is 110-330°C higher than the temperature of the second calcination. Using the aforementioned preferred calcination temperature difference can improve the utilization efficiency of the supported components and the number of complex acid centers.

[0046] In this invention, the range of selectable amounts of each substance is relatively wide. According to a preferred embodiment of this invention, in step (1), the mass ratio of molecular sieve, binder, matrix, skeleton stabilizer and water is 100:(10-110):(8-100):(0.9-19.5):(100-850). Using the aforementioned preferred mass ratio can ensure the strength requirements of the molecular sieve carrier.

[0047] In this invention, the mass ratio of the molecular sieve support, the metal oxide precursor, and water in step (2) has a wide range of selectable values. For this invention, the preferred mass ratio of the molecular sieve support, the metal oxide precursor, and water is 100:(0.5-25):(80-650). Using the aforementioned preferred mass ratio can achieve effective composite of the metal oxide and the molecular sieve and improve the dispersion of the loaded components.

[0048] In this invention, the range of types of adhesives is relatively wide, and commonly used adhesives can be used in this invention. For this invention, the adhesive is preferably selected from one or more of aluminum and / or silicon-containing polyhydroxy compounds, and more preferably from one or more of kaolin, montmorillonite, alumina sol and boehmite.

[0049] In this invention, the range of types of matrix is ​​relatively wide, and commonly used matrixes can be used in this invention. For this invention, the matrix is ​​preferably selected from one or more of layered silicates, aluminates and aluminosilicates, and sodium aluminate is preferred.

[0050] In this invention, the range of types of skeleton stabilizers is relatively wide, and commonly used skeleton stabilizers can all be used in this invention. For this invention, it is preferred that the skeleton stabilizer be selected from one or more of phosphates and phosphoric acid.

[0051] According to a preferred embodiment of the present invention, the skeleton stabilizer is preferably selected from a combination of ammonium phosphate and phosphoric acid, wherein the mass ratio of ammonium phosphate to phosphoric acid is (0.01-7.5):1, preferably (0.85-6.25):1, for example 0.85:1, 0.95:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1. Using the aforementioned preferred skeleton stabilizer enables the composite acid formed from the metal oxide / molecular sieve to possess high hydrothermal stability.

[0052] In this invention, the range of types of precursors for the metal oxide is selectable. Commonly used precursor types can be used in this invention. For this invention, the precursors for the metal oxide are preferably selected from one or more of nitrates, acetates, chlorides, sulfates, carbonates, fatty acid salts, and phosphates.

[0053] According to a preferred embodiment of the present invention, the method for preparing the catalyst of the present invention includes:

[0054] (1) Mix molecular sieve, binder, matrix, skeleton stabilizer with water, stir evenly, spray dry to form, and then calcine at 520-750℃ for 2-10 hours to obtain molecular sieve carrier;

[0055] (2) The molecular sieve support, the metal oxide precursor and water are mixed and stirred evenly, and then spray-dried again to form fluidized bed catalyst precursor A;

[0056] (3) The above-mentioned fluidized bed catalyst precursor A is calcined at 350-750℃ for 2-20 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0057] According to a particularly preferred embodiment of the present invention, in the preparation method, the calcination conditions in step (1) can be conventionally selected in the art. According to a particularly preferred embodiment of the present invention, the calcination temperature is 520-650℃ and the calcination time is 3-10 hours.

[0058] According to an embodiment of the present invention, in the preparation method described therein, the calcination conditions in step (1) can be conventionally selected in the art. According to a particularly preferred embodiment of the present invention, the calcination temperature is 420-600℃ and the calcination time is 4-8 hours.

[0059] According to an embodiment of the present invention, in the preparation method, the molecular sieve can be selected from a wide range. For the present invention, the molecular sieve is selected from molecular sieves containing at least one of eight-membered rings, ten-membered rings and twelve-membered rings in its structure, and having an acidity of 0.05-2.8 mmol / g.

[0060] For the present invention, the molecular sieve is further preferably selected from at least one of the ten-membered rings in the structure and has an acid content of 0.05-1.8 mmol / g.

[0061] This invention provides the application of the fluidized bed catalyst described herein in the production processes of aromatics and olefins.

[0062] The fluidized bed catalyst of the present invention is particularly suitable for use in the production processes of aromatics and olefins, and can achieve the technical goal of high yield of aromatics and olefins.

[0063] This invention provides a method for catalytically producing olefins / aromatics from dimethyl ether, the method comprising: contacting dimethyl ether with a catalyst in a fluidized bed reactor, wherein the catalyst is the fluidized bed catalyst described in this invention.

[0064] According to a preferred embodiment of the present invention, the contact conditions preferably include: a temperature of 370-580°C, a reaction pressure of 0.05-1.0 MPa, and a weight hourly space velocity (WHSV) of 0.07-2.5 h⁻¹ for dimethyl ether. -1 .

[0065] In this invention, the number of composite acids formed by the combination of metal oxide and molecular sieve refers to the number of acidic sites in the composite oxide formed by the combination of metal oxide and molecular sieve, which is calculated by the integral area of ​​the peaks corresponding to different acidic sites in the nuclear magnetic resonance spectrum.

[0066] In this invention, the total acid number of the catalyst refers to the total number of all acidic sites in the catalyst, which is determined by acid-base titration.

[0067] In this invention, the wear rate refers to the ratio of the worn mass to the initial mass per unit time, expressed as a percentage, and is measured using an air-jet multi-functional wear tester.

[0068] In this invention, the acidity of the molecular sieve refers to the surface acid that can be neutralized by acid-base neutralization, which is obtained by acid-base titration.

[0069] The catalyst of this invention is used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510°C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under the specified conditions, the catalyst was reacted with dimethyl ether in a fluidized bed reaction. The initial yield of olefins / aromatics reached 76%, and the catalyst could be continuously regenerated up to 55 times (based on a conversion rate greater than 85% of the initial conversion rate). Compared with the catalyst prepared by single spray drying molding, the initial yield of olefins / aromatics was only 58%, and the catalyst could be continuously regenerated only 39 times (based on a conversion rate greater than 85% of the initial conversion rate). The initial yield of olefins / aromatics was increased by 31%, and the number of continuous catalyst regenerations was increased by 41%, achieving better technical results.

[0070] The technical solution of the present invention will be further described below through embodiments, but the scope of protection of the present invention is not limited by the embodiments.

[0071] The evaluation conditions for the catalysts used in all embodiments and comparative examples of this invention conform to the following ranges: reaction temperature 420-680℃, reaction pressure 0.05-1.0 MPa, and feed weight hourly space velocity (WHSV) 0.20-2.0 h⁻¹. -1 The specific conditions are as described in the embodiments or comparative examples.

[0072] Example 1

[0073] (1) Mix 100g of MWW-structured MCM-22 molecular sieve (acidity of 2.56 mmol / g), 100g of sodium aluminate, 100g of kaolin, 10g of phosphoric acid and 825g of water, stir evenly, spray dry to form (drying temperature of 130℃, pressure of 0.1MPa), and then calcine at 540℃ for 8 hours to obtain molecular sieve carrier;

[0074] (2) Mix 120g of molecular sieve support, 30g of zinc nitrate and 640g of water, stir evenly, and then spray dry again (drying temperature is 110℃, pressure is 0.1MPa) to form a fluidized bed catalyst precursor;

[0075] (3) The above fluidized bed catalyst precursor was calcined at 360°C for 12 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0076] In the fluidized bed catalysts for producing aromatics and olefins, the loading of metal oxides was 4.9%, and the amount of composite acids formed by the combination of metal oxides and molecular sieves accounted for 55% of the total acid content of the catalyst. The wear ratio of the fluidized bed catalyst to the molecular sieve support was 0.66.

[0077] The catalyst was used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510 °C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under these conditions, the catalyst is reacted with dimethyl ether in a fluidized bed reaction, achieving an initial olefin / aromatic yield of 76%, and the catalyst can be continuously regenerated up to 55 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0078] Example 2

[0079] (1) Mix 100g of MFI-structured ZSM-5 molecular sieve (acid content of 0.63 mmol / g), 12g of alumina sol, 9g of montmorillonite, 8.5g of ammonium phosphate, 10g of phosphoric acid, and 100g of water, stir evenly, spray dry to form (drying temperature of 225℃, pressure of 1.2MPa), and then calcine at 735℃ for 2 hours to obtain molecular sieve carrier;

[0080] (2) Mix 120g of molecular sieve support, 5g of molybdenum acetate, 69.5g of magnesium nitrate and 350g of water, stir evenly, and spray dry again (conditions include: drying temperature of 200℃ and pressure of 1.2MPa) to form a fluidized bed catalyst precursor;

[0081] (3) The above fluidized bed catalyst precursor was calcined at 420°C for 2 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0082] In the fluidized bed catalysts for producing aromatics and olefins, the loading of metal oxides was 9.6%, and the amount of composite acids formed by the combination of metal oxides and molecular sieves accounted for 78% of the total acid content of the catalyst. The wear ratio of the fluidized bed catalyst to the molecular sieve support was 0.92.

[0083] The catalyst was used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510 °C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under these conditions, the catalyst is reacted with dimethyl ether in a fluidized bed reaction, achieving an initial olefin / aromatic yield of 72%, and the catalyst can be continuously regenerated up to 61 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0084] Example 3

[0085] (1) 100g of MOR-structured Beta molecular sieve (acidity of 0.06 mmol / g), 50g of alumina sol + 15g of boehmite, 45g of montmorillonite, 1.5g of ammonium phosphate + 0.24g of phosphoric acid and 275g of water were mixed and stirred evenly. The mixture was then spray-dried to form a molecular sieve carrier (temperature of 195℃ and pressure of 0.36MPa) and calcined at 620℃ for 5 hours.

[0086] (2) Mix 120g of molecular sieve support, 1.6g of gallium chloride + 0.5g of barium nitrate with 100g of water, stir evenly, and then spray dry again (conditions include: drying temperature of 150℃ and pressure of 0.40MPa) to form a fluidized bed catalyst precursor;

[0087] (3) The above fluidized bed catalyst precursor was calcined at 500°C for 5 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0088] In the fluidized bed catalysts for producing aromatics and olefins, the loading of metal oxides was 0.8%, and the amount of composite acid formed by the combination of metal oxides and molecular sieves accounted for 13% of the total acid amount in the catalyst. The wear ratio of the fluidized bed catalyst to the molecular sieve support was 0.35.

[0089] The catalyst was used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510 °C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under these conditions, the catalyst is reacted with dimethyl ether in a fluidized bed reaction, achieving an initial olefin / aromatic yield of 77%, and the catalyst can be continuously regenerated up to 63 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0090] Example 4

[0091] The method is the same as in Example 3, except that the temperature of the first spray drying is 150°C and the temperature of the second spray drying is 195°C.

[0092] The evaluation was the same as in Example 3, with an initial olefin / aromatic yield of 67% and the catalyst capable of continuous regeneration up to 53 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0093] Example 5

[0094] The method is the same as in Example 3, except that the temperature of the first roasting is 500°C and the temperature of the second roasting is 480°C.

[0095] The evaluation was the same as in Example 3, with an initial olefin / aromatic yield of 65% and the catalyst capable of continuous regeneration up to 50 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0096] Example 6

[0097] The method is the same as in Example 3, except that the skeleton stabilizer is entirely ammonium phosphate.

[0098] The evaluation was the same as in Example 3, with an initial olefin / aromatic yield of 63% and the catalyst capable of continuous regeneration up to 59 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0099] Comparative Example 1

[0100] The feeding process is the same as in Example 1, except that a single spray drying molding process is used, as detailed below:

[0101] (1) Mix 100g of MCM-22 molecular sieve, 100g of sodium aluminate, 100g of kaolin, 10g of phosphoric acid, zinc nitrate (with a loading of 4.9% based on zinc oxide) with 1465g of water, stir evenly, spray dry to form a shape, and then calcine at 540℃ for 8 hours to obtain fluidized bed catalyst precursor A.

[0102] (3) The above fluidized bed catalyst precursor was calcined at 480°C for 12 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0103] In the fluidized bed catalysts for producing aromatics and olefins, the loading of metal oxides was 4.9%, and the amount of composite acids formed by the combination of metal oxides and molecular sieves accounted for 84% of the total acid content of the catalyst. The wear ratio of the fluidized bed catalyst to the molecular sieve support was 1.02.

[0104] The catalyst of this invention is used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510°C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under these conditions, the catalyst is reacted with dimethyl ether in a fluidized bed reaction. The initial yield of olefins / aromatics is 58%, and the catalyst can be continuously regenerated 39 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0105] Comparative Example 2

[0106] The feeding method is the same as in Example 1, except that the impregnation method is used for preparation, as detailed below:

[0107] (1) Mix 100g of MCM-22 molecular sieve, 100g of sodium aluminate, 100g of kaolin, 10g of phosphoric acid and 825g of water, stir evenly, spray dry to form (drying temperature is 130℃, pressure is 0.1MPa), and then calcine at 540℃ for 8 hours to obtain molecular sieve carrier.

[0108] (2) Take 120g of the above molecular sieve, mix the 30g of zinc nitrate with 640g of water, stir evenly to form a solution, impregnate it into the molecular sieve carrier by impregnation, and dry it at 100℃ to form a fluidized bed catalyst precursor.

[0109] (3) The above fluidized bed catalyst precursor was calcined at 480°C for 12 hours to obtain a fluidized bed catalyst for producing aromatics and olefins.

[0110] In the fluidized bed catalyst for producing aromatics and olefins, the loading of metal oxides is 4.0%, the amount of composite acid formed by the combination of metal oxides and molecular sieves accounts for 8% of the total amount of acid in the catalyst, and the wear rate ratio of the fluidized bed catalyst to the molecular sieve support is 0.96.

[0111] The catalyst was used in the catalytic production of olefins / aromatics from dimethyl ether at a reaction temperature of 510 °C, a reaction pressure of 0.10 MPa, and a dimethyl ether weight hourly space velocity of 0.5 h⁻¹. -1 Under these conditions, the catalyst is reacted with dimethyl ether in a fluidized bed reaction. The initial yield of olefins / aromatics is 59%, and the catalyst can be continuously regenerated 46 times (based on a conversion rate greater than 85% of the initial conversion rate).

[0112] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A fluidized bed catalyst, characterized in that, The catalyst contains, by weight fraction: A 90-99.5% molecular sieve carrier; B 0.5-10% active metal oxides; The proportion of composite acids formed by the combination of active metal oxides and molecular sieves to the total acid content of the catalyst is 10-80%. The number of composite acids formed by the combination of active metal oxide and molecular sieve refers to the number of acidic sites in the composite oxide formed by the metal oxide and molecular sieve, which is calculated by the integrated area of ​​the peaks corresponding to different acidic sites in the nuclear magnetic resonance spectrum; the total number of acids in the catalyst refers to the total number of all acidic sites in the catalyst, which is determined by acid-base titration. The wear rate ratio of the fluidized bed catalyst to the molecular sieve support is 0.30-0.95; the wear rate refers to the ratio of the worn mass to the initial mass per unit time as a percentage, and is measured using an air-jet multifunctional wear tester.

2. The catalyst according to claim 1, wherein, The wear rate ratio of the fluidized bed catalyst to the molecular sieve support is 0.40-0.95; and / or The proportion of composite acids formed by the combination of metal oxides and molecular sieves to the total acid content of the catalyst is 11-70%.

3. The catalyst according to claim 2, wherein, The wear rate ratio of the fluidized bed catalyst to the molecular sieve support is 0.45-0.90; and / or The proportion of composite acids formed by the combination of metal oxides and molecular sieves to the total acid content of the catalyst is 12-66%.

4. The catalyst according to claim 1 or 2, wherein, Molecular sieves containing at least one of eight-membered, ten-membered, and twelve-membered rings in their structure, with an acidity of 0.05-2.8 mmol / g; and / or The active metal is selected from one or more of magnesium, calcium, barium, chromium, molybdenum, manganese, nickel, copper, zinc, gallium and silver.

5. The catalyst according to claim 4, wherein, The molecular screening is performed on one or more of the following structural types: CHA, MWW, MFI, BEA, MOR, and FAU.

6. A method for preparing the fluidized bed catalyst according to any one of claims 1-5, characterized in that, The method includes: (1) Molecular sieve, binder, optional matrix, skeleton stabilizer and water are mixed and stirred evenly, and then spray-dried and calcined to obtain molecular sieve carrier; (2) The molecular sieve support, the metal oxide precursor and water are mixed and stirred evenly, and then spray-dried and calcined to obtain a fluidized bed catalyst; The conditions for the first spray drying include: a temperature of 130-250 ℃ and a pressure of 0.1-1.3 MPa; The conditions for the second spray drying include: a temperature of 110-210℃ and a pressure of 0.1-1.3MPa; The conditions for the first roasting include: a temperature of 520-750℃ and a time of 2-10 hours; The conditions for the second roasting include: a temperature of 350-620℃ and a time of 2-20 hours.

7. The preparation method according to claim 6, wherein, The temperature of the first spray drying is 20-50°C higher than that of the second spray drying.

8. The preparation method according to claim 6 or 7, wherein, The temperature of the first roasting is 110-330℃ higher than that of the second roasting.

9. The preparation method according to claim 6 or 7, wherein, In step (1), the mass ratio of molecular sieve, binder, matrix, framework stabilizer and water is 100:(10-110):(8-100):(0.9-19.5):(100-850); and / or In step (2), the mass ratio of the molecular sieve support, the metal oxide precursor and water is 100:(0.5-25):(80-650).

10. The preparation method according to claim 6 or 7, wherein, The adhesive is selected from one or more polyhydroxy compounds containing aluminum and / or silicon; and / or The matrix is ​​selected from one or more of layered silicates, aluminates, and aluminosilicates; and / or The precursor of the metal oxide is selected from one or more of nitrates, acetates, chlorides, sulfates, carbonates, fatty acid salts, and phosphates; and / or The skeleton stabilizer is selected from one or more of phosphates and phosphoric acid.

11. The preparation method according to claim 10, wherein, The binder is one or more of kaolin, montmorillonite, alumina sol, and boehmite; and / or The matrix is ​​sodium aluminate; and / or The skeleton stabilizer is selected from a combination of ammonium phosphate and phosphoric acid, with a mass ratio of ammonium phosphate to phosphoric acid of (0.01-7.5):

1.

12. The preparation method according to claim 11, wherein, The skeleton stabilizer is selected from a combination of ammonium phosphate and phosphoric acid, with a mass ratio of ammonium phosphate to phosphoric acid of (0.85-6.25):

1.

13. The application of the fluidized bed catalyst according to any one of claims 1-5 in the production process of aromatics and olefins.

14. A method for catalytically producing olefins / aromatics from dimethyl ether, the method comprising: In a fluidized bed reactor, dimethyl ether is contacted with a catalyst, wherein the catalyst is a fluidized bed catalyst according to any one of claims 1-5.

15. The method according to claim 14, wherein, The contact conditions include: temperature 370-580℃, reaction pressure 0.05-1.0 MPa, and a weight hourly space velocity (WHSV) of 0.07-2.5 h⁻¹ for dimethyl ether. -1 .