SCM-34 molecular sieve, its preparation method and use

Abstract

The present invention discloses an SCM-34 molecular sieve, its preparation method, and its use. The SCM-34 molecular sieve contains aluminum, phosphorus, oxygen, and optionally silicon. In the XRD diffraction pattern of the molecular sieve, the 2θ angle of the most intense peak within the 2θ angle range of 5 to 50° is 7.59±0.2. The SCM-34 molecular sieve has a novel framework structure and can be used to prepare metal-containing AFI-type molecular sieves or SAPO-17 molecular sieves, meeting various demands for catalysts in chemical industrial production.

Description

[Technical Field]

[0001] The present invention relates to the field of molecular sieves, in particular to SCM-34 molecular sieve, its preparation method and use. [Background technology]

[0002] Porous materials are a type of solid compound with a regular pore structure. According to the definition of the International Union of Pure and Applied Chemistry (IUPAC), porous materials with pore diameters less than 2 nm are classified as micropore materials, while porous materials with pore diameters greater than 2 nm are classified as mesopore materials or macropore materials (pore diameters greater than 50 nm). Molecular sieve materials generally belong to the micropore category, with pore channel diameters less than 2 nm. They are a type of porous material characterized primarily by selective adsorption. Their unique pore channel system gives them the name "molecular sieve." Furthermore, these materials have a wide internal pore channel size distribution and a rich and diverse topological structure. They are widely used in adsorption separation, heterogeneous catalysis, support for various guest molecules, ion exchange, and other fields, achieving outstanding technological results.

[0003] Conventional zeolite molecular sieves are a type of crystalline silicate material, generally composed of silicon-oxygen tetrahedra [SiO4] linked together via shared oxygen atoms. 4- and aluminum-oxygen tetrahedron [AlO4] 5-These are collectively referred to as TO4 tetrahedra (primary structural units), and their silicon atoms can be partially isomorphously substituted with other elements, particularly trivalent or tetravalent elements such as Al, B, Ga, Ge, and Ti. Zeolite molecular sieves are widely used in fields such as catalysis, adsorption, and ion exchange due to their unique structural and chemical properties. The key factor determining the application performance of molecular sieves is the characteristics of their pore channels or cages, which are determined by the molecular sieve's unique crystalline structure. Therefore, obtaining molecular sieves with novel crystalline structures is of great significance for the application of molecular sieves.

[0004] In 1982, scientists ST Wilson and EM Flanigen of Union Carbide Corporation (UCC) in the United States successfully synthesized and developed a new family of molecular sieves, AlPO4-n, where n represents the model number, using aluminum and phosphorus sources and organic templates (US Pat. No. 4,310,440). Two years later, they successfully prepared another series of silicoaluminophosphate molecular sieves, SAPO-n (n represents the model number), by partially substituting Si atoms for Al and P atoms in the AlPO framework based on AlPO4-n. After substituting Si atoms for P or Al atoms in AlPO, a non-neutral framework consisting of SiO4, AlO4, and PO4 tetrahedra is formed in the SAPO-n structure. In this type of molecular sieve framework, silicon exists in two forms: (1) one Si atom replacing one P atom; and (2) two Si atoms replacing each pair of aluminum and phosphorus atoms. A typical SAPO-n molecular sieve is SAPO-34 molecular sieve, which has a CHA topology. This molecular sieve has a framework structure similar to chabazite, belongs to the cubic crystal system, and has a structural motif of AlO2. - , SiO2 and PO2 +The SAPO-34 molecular sieve is composed of tetrahedra, with a framework comprising ellipsoidal supercages and a three-dimensional intersecting structure with eight-membered ring pore channels. The diameter of the eight-membered ring pore channels is approximately 0.38 nm, and the supercages have pore opening diameters maintained at 0.43-0.50 nm. It has suitable proton acidity, a relatively large specific surface area, relatively good adsorption performance, relatively good thermal stability, good hydrothermal stability, and excellent shape selectivity of the pore channel structure for light olefins. Therefore, the SAPO-34 molecular sieve has been successfully commercialized as a catalyst for methanol to light olefins (MTO), demonstrating excellent catalytic activity and selectivity.

[0005] Currently, molecular sieves with known topology are primarily prepared by hydrothermal or solvothermal synthesis. The main steps in a typical hydrothermal or solvothermal synthesis process involve uniformly mixing reactants, such as metal sources, nonmetal sources, organic templates, and solvents, to obtain an initial sol, i.e., a crystallization mixture. Similar to the process used in terrestrial rock formations, the crystallization mixture is then placed in a PTFE-lined, stainless steel-walled reactor for crystallization under a constant temperature and autogenous pressure after sealing. Specifically, in the synthesis of silicoaluminophosphate SAPO-34 molecular sieves, the reaction mixture contains framework reactants (e.g., silica sol, phosphoric acid, and aluminum oxide), a structure-directing agent (SDA), and water. These are uniformly mixed and then placed in a drying oven at a fixed temperature (160-220°C) for several days for static or dynamic crystallization. Once the crystallization reaction is complete, the solid product containing SAPO-34 molecular sieves is filtered and dried for further use.

[0006] According to the International Molecular Sieve Association (IMSA) (as of August 4, 2021), there are a total of 255 molecular sieves with different topological structures, including the latest AlPO-91 molecular sieve with an ANO topology [U.S. Patent 10,336,622 B1, (2019) Crystalline metallophosphates, their method of preparation, and use, Yuhas, B.D., Wilson, K.N., Sylejmani-Rekaliu, M., Mowat, J.P.S., Sinkler, W.]. While many different crystalline molecular sieves have been developed, developing new molecular sieves with promising properties for gas separation and drying, hydrocarbon conversion reactions, and other applications remains a hot topic of current research. Summary of the Invention

[0007] The present invention provides SCM-34 molecular sieve, its preparation method and use, which is a new molecular sieve with a novel framework structure and can be used to prepare metal-containing AFI-type molecular sieves or SAPO-17 molecular sieves, thereby meeting various demands for catalysts in chemical industrial production.

[0008] According to a first aspect of the present invention, there is provided an SCM-34 molecular sieve, comprising aluminum, phosphorus, oxygen, and optionally silicon, wherein in an XRD diffraction pattern of the molecular sieve, the 2θ angle of the most intense peak within a 2θ angle range of 5 to 50° is 7.59±0.2, and the X-ray diffraction pattern of the SCM-34 molecular sieve comprises the X-ray diffraction peaks shown in the following table:

[0009] [Table 1]

[0010] The present invention further provides an SCM-34 molecular sieve, having a schematic chemical composition represented by the formula "Al2O3:xSiO2:yP2O", where 0≦x≦0.5 and 0.75≦y≦1.5, and in the XRD diffraction data of the molecular sieve, the 2θ degree of the most intense peak within the range of 5 to 50° is 7.59±0.2, and the X-ray diffraction pattern of the SCM-34 molecular sieve includes the X-ray diffraction peaks shown in the following table:

[0011] [Table 2]

[0012] Furthermore, the X-ray diffraction pattern of the SCM-34 molecular sieve further includes the X-ray diffraction peaks shown in the table below.

[0013] [Table 3]

[0014] Furthermore, the X-ray diffraction pattern of the SCM-34 molecular sieve further includes the X-ray diffraction peaks shown in the table below.

[0015] [Table 4]

[0016] Here, the incident light for X-ray diffraction is CuKα1.

[0017] According to a second aspect of the present invention, there is provided a method for preparing the aforementioned SCM-34 molecular sieve, comprising: subjecting a mixture of an aluminum source, a phosphorus source, organic templates R1 and R2, solvents S1, S2 and S3, and an optionally added silicon source to a crystallization treatment to obtain the SCM-34 molecular sieve.

[0018] wherein the organic template R1 is selected from one or more of quaternary ammonium salts and / or quaternary ammonium bases; the organic template R2 is selected from one or more of imidazole, pyrrolidine, and their derivatives; the solvent S1 is selected from one or more of amide-based solvents; the solvent S2 is selected from one or more of cyclic organic solvents; and the solvent S3 is selected from one or more of water or lower alcohols; wherein the organic template R1 and the organic template R2 represent different organic templates; and the solvents S1, S2, and S3 represent different solvents.

[0019] Further, the organic template R1 is selected from one or more of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide, and tetrabutylammonium hydroxide, and the organic template R2 is selected from one or more of imidazole, 2-methylimidazole, 4-methylimidazole, 1-(3-aminopropyl)imidazole, 2-ethyl-4-methylimidazole, pyrrolidine, and 1-(3-pyrrolidine). pyrrolidine, N-ethyl-2-aminomethylpyrrolidine; said solvent S1 is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N,N-dibutylformamide; said solvent S2 is selected from one or more of 1,4-dioxane, cyclohexane, cyclohexanone, cyclohexanol; and / or said solvent S3 is selected from one or more of methanol, ethanol, ethylene glycol, butanol, and water.

[0020] Furthermore, the organic template R1 is preferably one or more of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; the organic template R2 is preferably one or more of 1-(3-aminopropyl)imidazole, 2-ethyl-4-methylimidazole, and N-ethyl-2-aminomethylpyrrolidine; the solvent S1 is preferably one or two of N,N-dimethylacetamide and N,N-dibutylformamide; the solvent S2 is preferably one or two of 1,4-dioxane and cyclohexanone; and / or the solvent S3 is preferably one or two of ethanol and water, with water preferably being deionized water.

[0021] Furthermore, in the mixture, the molar composition of the Al2O3-based aluminum source, the SiO2-based silicon source, the P2O5-based phosphorus source, the organic template R1+R2, and the solvent S1+S2+S3 is SiO2 / Al2O3=0 to 1, preferably 0.1 to 0.75, P2O5 / Al2O3=0.5 to 2, preferably 0.75 to 1.5, template R1+R2 / Al2O3=1 to 200, preferably 5 to 50, and solvent S1+S2+S3 / Al2O3=5 to 500, preferably 35 to 120.

[0022] Furthermore, the molar ratio of the organic template R1 to the organic template R2 is 0.01 to 1:1, preferably 0.1 to 0.25:1.

[0023] Furthermore, the molar ratio of the solvent S1, solvent S2 and solvent S3 is 1:0.01-1:1-100, preferably 1:0.05-0.5:10-80.

[0024] Furthermore, the aluminum source is selected from one or more of aluminum isopropoxide, aluminates, metaaluminates, aluminum salts, aluminum hydroxides, aluminum oxides, and aluminum-containing minerals, and is preferably selected from one or two of aluminates and metaaluminates; the silicon source is selected from one or more of organic silicon, amorphous silicon dioxide, silica sol, solid silicon oxide, silica gel, diatomaceous earth, and water glass, and is preferably selected from one or more of amorphous silicon dioxide, silica sol, and solid silicon oxide; and the phosphorus source is selected from at least one of phosphoric acid, ammonium monohydrogen phosphate, and ammonium dihydrogen phosphate, and is preferably orthophosphoric acid.

[0025] Furthermore, in the preparation method, a stirring and precipitation treatment is carried out before the crystallization treatment, and the stirring time is 0.5 to 5 hours, and the precipitation time is 1 to 12 hours.

[0026] Further, the conditions for the crystallization treatment include a crystallization temperature of 120 to 200°C, preferably 140 to 180°C, more preferably 140 to 160°C, and a crystallization time of 1 to 5 days, preferably 3 to 5 days, more preferably 4 to 5 days.

[0027] Furthermore, after the crystallization treatment, conventional post-treatments such as filtering, washing and drying to obtain a molecular sieve, and optionally calcining the obtained molecular sieve, are carried out.

[0028] According to a third aspect of the present invention, there is provided a molecular sieve composition comprising the SCM-34 molecular sieve according to the first aspect or the SCM-34 molecular sieve prepared according to the method of the second aspect, and a binder. For example, the method for preparing the molecular sieve composition comprises the following steps:

[0029] a. Ammonium-exchange the SCM-34 molecular sieve according to the present invention and calcinate it to obtain a hydrogen-form SCM-34 molecular sieve; b. A certain amount of the hydrogen-formed SCM-34 molecular sieve obtained in step a is weighed, uniformly mixed with a certain amount of a binder and a pore-forming agent, and then kneaded and extruded with a certain amount of water and a dilute nitric acid solution to obtain a cylindrical sample, which is dried at 80 to 120°C and calcined at 500 to 650°C to obtain a catalyst sample, wherein the pore-forming agent is at least one selected from sesbania powder, carboxymethyl cellulose, and starch.

[0030] According to a fourth aspect of the present invention, there is provided a use of a molecular sieve, i.e., the SCM-34 molecular sieve described in the first aspect, the SCM-34 molecular sieve prepared according to the method described in the second aspect, or the SCM-34 molecular sieve composition described in the third aspect, for preparing a metal-containing AFI molecular sieve, which has a special acid distribution and a novel morphology and is applicable to the methanol-to-olefin reaction.

[0031] The metal element of the metal-containing AFI molecular sieve is an alkaline earth metal and / or transition metal element, preferably at least one metal element of Group IIA, IIB, IIIB, IVB, or VIIIB, more preferably at least one of magnesium, zinc, lanthanum, titanium, and cobalt, and the content of the metal element is preferably 0.01% to 1.0% based on the mass of the molecular sieve.

[0032] The metal-containing AFI molecular sieve simultaneously contains weak acid centers, medium-strong acid centers, and strong acid centers, and the acid content distribution is as follows: weak acid content accounts for 30-50% of the total acid content, medium-strong acid content accounts for 5-20% of the total acid content, and strong acid content accounts for 30-65% of the total acid content.

[0033] The method for preparing the metal-containing AFI molecular sieve includes using the SCM-34 molecular sieve of the present invention as a reaction raw material, mixing it with a solvent SI, an organic template R, and an optionally added first silicon source to prepare precursor A, and then mixing precursor A with a solvent SII, a metal source, and an optionally added second silicon source to prepare the AFI molecular sieve.

[0034] Furthermore, based on the mass m of the supplied SCM-34 molecular sieve, the supply mass ratios of the raw materials used are silicon source / m=0-20, organic template R / m=1-20, metal source / m=0.01-1, and solvent (SI+SII) / m=2-100, preferably silicon source / m=0.1-10, organic template R / m=2-10, metal source / m=0.05-0.5, and solvent (SI+SII) / m=10-50, and more preferably silicon source / m=0.5-1, organic template R / m=3-6, metal source / m=0.1-0.25, and solvent (SI+SII) / m=20-40.

[0035] Furthermore, the mass ratio of the solvent SI to the solvent SII is 0.1 to 20:1.

[0036] Furthermore, the method for producing AFI molecular sieve specifically includes the following steps: a. Add SCM-34 molecular sieve, organic template R to solvent SI, selectively add the first silicon source, stir, and heat-treat to obtain precursor A; b. Mixing a metal source with solvent SII and selectively adding a second silicon source to obtain mixture B; c. Add precursor A to mixture B under stirring to form a crystallization mixture; d. The mixture for crystallization in step c is kept at 60-100°C and stirred for 0.5-2 hours to carry out a crystallization reaction, thereby obtaining AFI molecular sieve.

[0037] Furthermore, the organic template R is an organic amine, and the organic amine is preferably selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide, tetrabutylammonium hydroxide, benzyltriethylammonium chloride, benzyltrimethylammonium hydroxide, triethylamine, n-butylamine, di-n-propylamine, diisopropylamine, ethylenediamine, and ethylamine, more preferably at least one of tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, and triethylamine.

[0038] Furthermore, the solvent SI or solvent SII is each independently selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, ethylene glycol, ethanol, and water, and preferably selected from at least one of N,N-dimethylformamide, ethanol, and water.

[0039] Furthermore, the first silicon source or the second silicon source is independently selected from at least one of organic silicon, amorphous silicon dioxide, silica sol, and solid silicon oxide, and preferably selected from at least one of amorphous silicon dioxide, silica sol, and solid silicon oxide.

[0040] Furthermore, the metal source is selected from at least one of nitrates, sulfates and acetates of the corresponding alkaline earth metal and / or transition metal elements, preferably the nitrates of the corresponding metals.

[0041] Furthermore, in step a, the heat treatment is carried out at 40 to 80° C. for 0.5 to 2 hours.

[0042] Furthermore, in step d, the crystallization reaction conditions are 110 to 160°C, preferably 110 to 145°C, more preferably 120 to 135°C, and the reaction time range is 10 to 120 minutes, preferably 20 to 100 minutes, more preferably 30 to 90 minutes.

[0043] Furthermore, in step d, the crystallized product may undergo post-treatment steps such as filtration, washing, drying, calcination, etc., and conventional operating conditions in the art may be adopted for the post-treatment steps.

[0044] Specifically, the filtration can be performed by simply filtering the resulting product mixture. The washing can be performed using, for example, deionized water and / or ethanol. The drying temperature can be, for example, 40 to 250°C, preferably 60 to 150°C, and the drying time can be, for example, 3 to 30 hours, preferably 5 to 20 hours. The drying can be performed under atmospheric pressure or reduced pressure. The calcination can be performed by any method generally known in the art. For example, the calcination temperature is generally 300 to 800°C, preferably 400 to 650°C, and the calcination time is generally 1 to 12 hours, preferably 3 to 12 hours. The calcination is generally performed in air or an oxygen-containing atmosphere such as an oxygen atmosphere.

[0045] Metal-containing AFI molecular sieves can be used in the reaction of methanol to hydrocarbons. Furthermore, the reaction conditions for methanol to hydrocarbons are as follows: methanol is used as the raw material, the reaction temperature is 400-600°C, the reaction pressure is 0.01-10 MPa, and the reaction time is 0.1-15 h. -1 is the weight hourly space velocity of methanol.

[0046] The preparation method of the AFI molecular sieve of the present invention allows rapid crystallization at lower temperatures, for example, the minimum reaction temperature is 110°C and the fastest reaction time is 10 minutes, and the obtained AFI molecular sieve is suitable for the reaction of methanol to olefins, achieving good technical effects.

[0047] A fifth aspect of the present invention provides a use of a molecular sieve. The SCM-34 molecular sieve described in the first aspect, the SCM-34 molecular sieve prepared according to the method described in the second aspect, or the SCM-34 molecular sieve composition described in the third aspect is used to prepare a SAPO-17 molecular sieve. The SAPO-17 molecular sieve prepared here can be used in the industrial production of downstream methanol products, the industrial production of downstream synthesis gas products, and hydrocarbon cracking, and has excellent performance.

[0048] In one embodiment, the method for preparing SAPO-17 molecular sieve comprises the following steps:

[0049] 1) mixing an organic template cR with a first organic solvent cS and performing a first heat treatment to obtain a precursor P; 2) Mixing the SCM-34 molecular sieve of the present invention, the optionally added silicon source, and the second organic solvent cS, and then performing a second heat treatment to obtain a mixture material M; 3) mixing the precursor P obtained in step 1) with the mixture material M obtained in step 2) to form a crystallization mixture; 4) The mixture for crystallization obtained in step 3) is pre-treated and then subjected to crystallization reaction to obtain SAPO-17 molecular sieve.

[0050] Furthermore, in step 1), the organic template cR is at least one of 1,10-phenanthroline, 2,2-bipyridine, 4,4-bipyridine, piperazine, cyclohexylamine, and pyridine, and preferably at least one of piperazine and cyclohexylamine.

[0051] Furthermore, in steps 1) and 2), the first organic solvent cS and the second organic solvent cS are each independently at least one of tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-epoxycyclopentane, 1,4-dioxane, cyclohexanone, and cyclohexanol, and preferably at least one of 1,4-dioxane and cyclohexanone.

[0052] Furthermore, the mass ratio of the added SCM-34 molecular sieve, organic template cR, and total organic solvent cS is 0.1-1:1-10:1-10. Here, "total organic solvent" refers to the total amount of the first organic solvent cS in step 1) and the second organic solvent cS in step 2). The mass ratio of the first organic solvent cS in step 1) to the second organic solvent cS in step 2) is 1:0.1-1.

[0053] Furthermore, in step 1), the temperature of the first heat treatment is 40 to 90° C. and the time is 1 to 5 hours, and preferably the temperature of the first heat treatment is 55 to 75° C. and the time is 2 to 4 hours.

[0054] Furthermore, in step 2), the temperature of the second heat treatment is 40 to 90° C. and the time is 1 to 5 hours, and preferably the temperature of the second heat treatment is 50 to 70° C. and the time is 2 to 3 hours.

[0055] Furthermore, in step 2), the mass ratio of the silicon source to the SCM-34 molecular sieve is 0-10:1, preferably 0.1-10:1.

[0056] Furthermore, in step 2), the silicon source is at least one of organic silicon, amorphous silicon dioxide, silica sol, silica, silica gel, diatomaceous earth, and water glass, and preferably at least one of amorphous silicon dioxide, silica sol, and silica.

[0057] Furthermore, in step 3), the mixing is preferably performed by adding the precursor P to the mixture material M while stirring, and the stirring time is 0.5 to 5 hours, preferably 2.5 to 4 hours.

[0058] Furthermore, in step 4), the pretreatment conditions are stirring at 80 to 110°C for 0.5 to 5 hours.

[0059] Furthermore, in step 4), the crystallization reaction is carried out at 115 to 140° C. for 1 to 8 hours.

[0060] The SAPO-17 molecular sieve can be used in the methanol to hydrocarbon and syngas to olefin reactions.

[0061] Furthermore, the reaction conditions for converting methanol to hydrocarbons are as follows: methanol is used as the raw material, the reaction temperature is 400 to 600°C, the reaction pressure is 0.01 to 10 MPa, and the methanol weight space velocity is 0.1 to 15 h -1 is.

[0062] Furthermore, the reaction conditions for converting synthesis gas to olefins are as follows: synthesis gas is used as the raw material, H2 / CO = 0.5 to 1:1, reaction temperature 200 to 400°C, reaction pressure 0.1 to 10 MPa, synthesis gas weight hourly space velocity 20 to 2000 h -1 is.

[0063] When the SAPO-17 molecular sieve prepared according to the present invention is used in the reaction of methanol to hydrocarbons, within the range of the evaluation conditions, the methanol conversion rate is 100%, the single-pass yield of ethylene and propylene reaches up to 84.5%, the selectivity ratio (ethylene / propylene) is in the range of 2.5-3.0, and the catalyst has good stability.

[0064] In the process of using the SAPO-17 molecular sieve prepared by the present invention in the synthesis gas-to-olefin reaction, the CO conversion rate reaches a maximum of 51.7%, the C2-C4 olefin selectivity reaches a maximum of 85.6%, and the selectivity ratio (ethylene / propylene) is in the range of 2.5-3.0 within the set evaluation range.

[0065] Compared with the prior art, the preparation of SAPO-17 molecular sieves by the method of the present invention has a shorter crystallization time, while at the same time significantly shortening the overall synthesis time of SAPO-17 molecular sieves and allowing for the preparation to be carried out at a lower temperature. The SAPO-17 molecular sieve prepared by the crystal transformation of SCM-34 molecular sieve of the present invention has significantly improved application performance. The SAPO-17 molecular sieve synthesized by this method exhibits excellent performance in the industrial production of downstream methanol products, downstream synthesis gas products, and hydrocarbon cracking. For example, in the methanol conversion reaction to hydrocarbons, it has a high total yield of ethylene and propylene and a high selectivity ratio (ethylene / propylene). In the synthesis gas conversion reaction to hydrocarbons, it has a high selectivity for C2-C4 olefins and a high selectivity ratio (ethylene / propylene). [Brief explanation of the drawings]

[0066] [Figure 1] 1 is an X-ray diffraction (XRD) pattern of the molecular sieve prepared in Example 1. [Figure 2] 1 is a SEM photograph of the molecular sieve prepared in Example 1. [Figure 3] 1 is an XRD pattern of the AFI molecular sieve synthesized in Example 9. [Figure 4] 1 is a SEM photograph of the AFI molecular sieve synthesized in Example 9. [Figure 5] 1 is a SEM photograph of the AFI molecular sieve synthesized in Example 9. [Figure 6] 1 shows the TPD pattern of the AFI molecular sieve synthesized in Example 9. [Figure 7] 1 is an XRD pattern of the SAPO-17 molecular sieve in Example 13. [Figure 8] 1 is a SEM photograph of the SAPO-17 molecular sieve in Example 13. [Figure 9] 1 is an XRD pattern of the SAPO-17 molecular sieve in Comparative Example 1. [Figure 10] 1 shows an SEM photograph of the SAPO-17 molecular sieve in Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0067] In order to facilitate understanding of the present invention, the present invention provides the following examples. However, it will be understood that the examples are merely intended to help those skilled in the art understand the present invention and are not intended to specifically limit the present invention. The endpoints and any values ​​of the ranges disclosed in the present invention 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.

[0068] In the present invention, the structure of the molecular sieve is determined by X-ray diffraction pattern (XRD). The X-ray diffraction pattern (XRD) of the molecular sieve is measured by an X-ray powder diffractometer using a Cu-Kα radiation source, Kα wavelength λ=1.5405980 Å, and a nickel filter.

[0069] In this study, an X'Pert PRO X-ray powder diffractometer (XRD) manufactured by PANalytical BV was used, with a voltage of 40 kV, a current of 40 mA, and a scan range of 3.5 to 50°. The morphology of the product was photographed using an S-4800 field emission scanning electron microscope (Fe-SEM) manufactured by Hitachi, Ltd., Japan.

[0070] It is expressly stated that two or more aspects (or embodiments) disclosed in relation to the present invention can be combined with each other in any manner, and the technical solutions (such as methods or systems) thus formed are part of the original disclosure in this specification and fall within the protection scope of the present invention.

[0071] Unless otherwise clearly indicated, all percentages, parts, ratios, etc. described in the present invention are by weight unless they are inconsistent with the common understanding of those skilled in the art when it comes to weight.

[0072] In the embodiment of the present invention, the raw materials are as follows:

[0073] Aluminum sulfate [Al2(SO4)3·18H2O]: an industrial product containing 15.7% by weight of Al2O3; Aluminum isopropoxide [Al(iPr)3]: contains 24.9 wt% Al2O3; Aluminum nitrate [Al(NO3)3·9H2O]: contains 27.5 wt% Al2O3; Phosphoric acid (purity ≥ 85 wt.%): a commercially available product containing 72.3 wt.% P2O5; Acidic silica sol (40 wt.% aqueous solution): a commercially available product containing 40 wt.% SiO2; Silica: Contains 99% by weight of SiO2; Magnesium nitrate [Mg(NO3)2·6H2]: contains 15.6 wt% MgO; Cobalt nitrate [Co(NO3)2·6H2]: containing 25.7 wt% CoO; Zinc nitrate [Zn(NO3)2·6H2]: Contains 27.3 wt% ZnO.

[0074] I. Preparation of SCM-34 molecular sieve Example 1 3.8 g of aluminum nitrate [Al(NO3)3·9H2O] was dissolved in 4.3 mL of deionized water and mixed to form solution C. Next, 1.8 g of phosphoric acid (purity ≥ 85 wt.%), 10.8 g of tetrabutylammonium hydroxide (40 wt.% aqueous solution, MkSeal), and 10.4 g of 1-(3-aminopropyl)imidazole were added to solution C and stirred for 0.5 h, followed by precipitation for 12 h to obtain solution C'. Next, 0.1 g of silica (Aladdin, S104573, ≥ 99%), 1.4 mL of N,N-dibutylformamide, and 0.4 mL of cyclohexanone were slowly added to solution C' and stirred for 3.5 h. The mixture was then heated at 90 °C for 8 h to form a homogeneous crystallization mixture. The molar ratio of the Al2O3-based aluminum source, SiO2-based silicon source, and PO5-based phosphorus source, total template, and total solvent was Al2O3:SiO2:PO5:template R:solvent S = 1:0.1:1.5:5:35, with template R1 (tetrabutylammonium hydroxide) / template R2 (1-(3-aminopropyl)imidazole) = 0.2, and solvent S1 (N,N-dibutylformamide) / solvent S2 (cyclohexanone) / solvent S3 (water) = 1:0.5:78.5. The crystallization mixture was crystallized at 140 °C for 5 days. The product was filtered, washed, and dried at 100 °C for 8 h to obtain product SCM-34. The X-ray diffraction pattern data is shown in Table 1, the X-ray diffraction pattern in Figure 1, and an SEM image in Figure 2.

[0075] [Table 5]

[0076] Example 2 20.4 g of aluminum isopropoxide (Al(iPr)3) was dissolved in 207.2 mL of water and mixed to form solution C. Then, 8.6 g of phosphoric acid (purity ≥ 85 wt.%), 294.8 g of tetrabutylammonium hydroxide (40 wt.% aqueous solution, MkSeal), and 569.1 g of 1-(3-aminopropyl)imidazole were added to solution C and stirred for 5 h, followed by precipitation for 1 h to obtain solution C'. Next, 15.0 g of acidic silica sol (Ludox HS type, 40 wt. aqueous solution), 313.2 mL of N,N-dimethylbutyramide, and 9.8 mL of cyclohexanone were slowly added to solution C' and stirred for 2.5 h, followed by heat treatment at 100 °C for 6 h to form a homogeneous crystallization mixture. The molar ratios of the Al2O3-based aluminum source, SiO2-based silicon source, and PO5-based phosphorus source, total template, and total solvent were Al2O3:SiO2:PO5:template R:solvent S = 1:0.5:0.75:25:120, template R1 (tetrabutylammonium hydroxide) / template R2 (1-(3-aminopropyl)imidazole) = 0.1, and solvent S1 (N,N-dimethylbutyramide) / solvent S2 (cyclohexanone) / solvent S3 (water) = 1:0.05:11. The crystallization mixture was crystallized at 140 °C for 4 days. The product was filtered, washed, and dried at 120 °C for 4 h to obtain product SCM-34. The X-ray diffraction pattern data are shown in Table 2, and the XRD pattern is similar to Figure 1.

[0077] [Table 6]

[0078] Example 3 1021.2 g of aluminum isopropoxide was dissolved in 1078.1 mL of water and mixed to form solution C. Then, 432.4 g of phosphoric acid (purity ≥ 85 wt.%), 24016.3 g of tetraethylammonium hydroxide (40 wt.% aqueous solution, Sigma-Aldrich), and 54426.1 g of 1-(3-aminopropyl)imidazole were added to solution C and stirred for 3 h, followed by precipitation for 6 h to obtain solution C'. Next, 450.0 g of silica (Aladdin, S104573, ≥ 99%), 4528.8 mL of N,N-dimethylbutylamine, and 706.6 mL of cyclohexanone were slowly added to solution C' and stirred for 1.5 h, followed by heat treatment at 90 °C for 11 h to form a homogeneous crystallization mixture. The molar ratios of the Al2O3-based aluminum source, SiO2-based silicon source, and PO5-based phosphorus source, total template, and total solvent were Al2O3:SiO2:PO5:Template R:Solvent S = 1:0.75:0.75:50:90, Template R1 (tetraethylammonium hydroxide) / Template R2 (1-(3-aminopropyl)imidazole) = 0.15, and Solvent S1 (N,N-dimethylbutyramide) / Solvent S2 (cyclohexanone) / Solvent S3 (water) = 1:0.25:30. The crystallization mixture was crystallized at 140 °C for 5 days. The product was filtered, washed, and dried at 90 °C for 10 h to obtain product SCM-34. Its X-ray diffraction pattern data are shown in Table 3, and the XRD pattern is similar to Figure 1.

[0079] [Table 7]

[0080] Example 4 375.1 g of aluminum nitrate was dissolved in 405.1 mL of water and mixed to form solution C. Then, 138.4 g of phosphoric acid (purity ≥ 85 wt.%), 2827.6 g of tetrabutylammonium hydroxide (40 wt.% aqueous solution, MkSeal), and 3209.7 g of 1-(3-aminopropyl)imidazole were added to solution C and stirred for 2 h, followed by precipitation for 8 h to obtain solution C'. Next, 36.1 g of silica (Aladdin, S104573, ≥ 99%), 299.1 mL of N,N-dimethylformamide, and 18.7 mL of cyclohexanone were slowly added to solution C' and stirred for 4 h, followed by heat treatment at 110 °C for 3 h to form a homogeneous crystallization mixture. The molar ratios of the Al2O3-based aluminum source, SiO2-based silicon source, and PO5-based phosphorus source, total template, and total solvent were Al2O3:SiO2:PO5:template R:solvent S = 1:0.3:1.2:15:60, template R1 (tetrabutylammonium hydroxide) / template R2 (1(3-aminopropyl)imidazole) = 0.17, and solvent S1 (N,N-dimethylbutyramide) / solvent S2 (cyclohexanone) / solvent S3 (water) = 1:0.1:62. The crystallization mixture was crystallized at 140 °C for 5 days. The product was filtered, washed, and dried at 120 °C for 4 h to obtain product SCM-34. Its X-ray diffraction pattern data are shown in Table 4, and the XRD pattern is similar to Figure 1.

[0081] [Table 8]

[0082] Example 5 33.3 g of aluminum sulfate [Al2(SO4)3·18H2O] was dissolved in 66.3 mL of water and mixed to form solution C. Next, 5.2 g of phosphoric acid (purity ≥ 85 wt.%), 117.0 g of tetrabutylammonium hydroxide (40 wt.% aqueous solution, MkSeal), and 102.6 g of 1-(3-aminopropyl)imidazole were added to solution C and stirred for 3 h, followed by precipitation for 6 h to obtain solution C'. Next, 6.1 g of acidic silica sol (Ludox HS type, 40 wt.% aqueous solution), 25.5 mL of N,N-dimethylbutylamine, and 4.8 mL of cyclohexanone were slowly added to solution C' and stirred for 4.5 h. Then, the mixture was heated at 80 °C for 12 h to form a homogeneous crystallization mixture. The molar ratios of the Al2O3-based aluminum source, SiO2-based silicon source, and P2O5-based phosphorus source, total template, and total solvent were Al2O3:SiO2:P2O5:total template agent R:total solvent S = 1:0.4:0.9:10:80, template agent R1 (tetrabutylammonium hydroxide) / template agent R2 (1-(3-aminopropyl)imidazole) = 0.22, and solvent S1 (N,N-dimethylbutyramide) / solvent S2 (cyclohexanone) / solvent S3 (water) = 1:0.3:48. The crystallization mixture was crystallized at 140 °C for 5 days. The product was filtered, washed, and dried at 100 °C for 8 h to obtain product SCM-34. Its X-ray diffraction pattern data are shown in Table 5, and the XRD pattern is similar to Figure 1.

[0083] [Table 9]

[0084] Example 6 266.6 g of aluminum sulfate was dissolved in 157.5 mL of water and mixed to form solution C. Then, 50.7 g of phosphoric acid (purity ≥ 85 wt%), 614.6 g of tetraethylammonium hydroxide (25 wt% aqueous solution), and 801.3 g of N-ethyl-2-aminomethylpyrrolidine (purity 95%, Meryer) were added to solution C and stirred for 4.5 h, followed by precipitation for 3.5 h to obtain solution C'. Next, 18.1 g of acidic silica sol (Ludox HS type, 40 wt% aqueous solution), 124.9 mL of N,N-dimethylformamide, and 60.2 mL of 1,4-dioxane were slowly added to solution C' and stirred for 3.5 h, followed by heat treatment at 80 °C for 12 h to form a homogeneous crystallization mixture. The molar ratios of the Al2O3-based aluminum source, SiO2-based silicon source, and PO5-based phosphorus source, total template, and total solvent were Al2O3:SiO2:PO5:total template R:total solvent S = 1:0.3:1.1:20:100, template R1 (tetraethylammonium hydroxide) / template R2 (N-ethyl-2-aminomethylpyrrolidine) = 0.15, and solvent S1 (N,N-dimethylbutylamine) / solvent S2 (1,4-dioxane) / solvent S3 (water) = 1:0.4:22. The crystallization mixture was crystallized at 140 °C for 5 days. The product was filtered, washed, and dried at 100 °C for 8 h to obtain product SCM-34. Its X-ray diffraction pattern data are shown in Table 6, and the XRD pattern is similar to Figure 1.

[0085] [Table 10]

[0086] II. Synthesis and Use of Metal-Containing AFI-Type Molecular Sieves 1. Synthesis of metal-containing AFI-type molecular sieves from SCM-34 molecular sieves Example 7 At room temperature, 136.2 g of the SCM-34 molecular sieve obtained in Example 1, 34.7 g of triethylamine [TEA], 237.6 g of tetraethylammonium bromide [TEABr], and 12008.3 g of deionized water were thoroughly stirred and then heat-treated at 80°C for 0.5 h to obtain precursor A. 1.4 g of magnesium nitrate [Mg(NO3)2·6H2O, purity ≥ 98 wt.%] was dissolved in 1161.7 mL of deionized water and thoroughly stirred for 1.5 h to form mixture B. Precursor A was added to mixture B under sealed stirring conditions and stirred for 3.5 h, followed by stirring at 85°C for another 1 h. The mixture was then crystallized at 160°C for 10 min, filtered, washed, dried at 100°C for 6 h, and then heated to 600°C and calcined at constant temperature for 4 h to obtain AFI molecular sieve (hereinafter the same). After ICP testing, SSP5-1 contained 0.18 wt.% Mg element, and its XRD pattern was similar to Figure 3, and its SEM pattern was similar to Figures 4 and 5. The metal content and acid distribution of the product are shown in Table 7.

[0087] Example 8 Precursor A was obtained by thoroughly stirring 20.8 g of the SCM-34 molecular sieve obtained in Example 2, 208 g of triethylamine (TEA), 4.2 g of silica (SiO2, 99 wt.%), and 685.6 g of deionized water at room temperature and then heat-treating at 60°C for 1 hour. 1.1 g of cobalt nitrate (Co(NO3)2·4H2O, purity ≥ 99 wt.%) and 6.3 g of silica (SiO2, 99 wt.%) were dissolved in 354.4 mL of deionized water and thoroughly stirred for 2.5 hours to form mixture B. Precursor A was then added to mixture B under sealed stirring conditions, followed by stirring for 0.5 hours and then further stirring at 100°C for 0.5 hours. The stirred mixture was then crystallized at 110°C for 120 minutes, filtered, washed, and dried at 90°C for 8 hours. It was then heated to 500°C and calcined at this temperature for 8 hours to obtain a product designated SSP5-2. After ICP testing, SSP5-2 contained 0.01 wt.% Co. Its XRD pattern was similar to that shown in Figure 3, and its SEM pattern was similar to that shown in Figures 4 and 5. The metal content and acid distribution of the product are shown in Table 7.

[0088] Example 9 Precursor A was obtained by thoroughly stirring 12110.7 g of SCM-34 molecular sieves obtained in Example 4, 8106.3 g of benzyltriethylammonium chloride [TEBAC, 99 wt.%], 4004.4 g of tetraethylammonium hydroxide [TEAOH, 50%], and 15363.4 g of acidic silica sol [SiO2, 40 wt.%] at room temperature for 1.5 h, followed by heat treatment at 60 °C for 1.5 h. 6055.4 g of zinc nitrate [Zn(NO3)2·6H2O, purity ≥ 99 wt.%] and 15363.4 g of acidic silica sol [SiO2, 40 wt.%] were dissolved in 4052.9 mL of deionized water and thoroughly stirred for 2.5 h to form mixture B. Precursor A was then added to mixture B under sealed stirring conditions, followed by stirring for 0.5 h and then heating at 90 °C for 0.9 h. The stirred mixture was then crystallized at 115°C for 86 minutes, filtered, washed, and dried at 80°C for 9 hours. It was then heated to 550°C and calcined at this temperature for 5 hours to obtain a product designated SSP5-3. After ICP testing, SSP5-3 contained 1.0 wt.% Zn. Its XRD pattern is shown in Figure 3, SEM patterns in Figures 4 and 5, and TPD pattern in Figure 6. The metal content and acid distribution of the product are listed in Table 7.

[0089] [Table 11]

[0090] 2. Use of metal-containing AFI molecular sieves in the reaction of methanol conversion to hydrocarbons Example 10 The SSP5-1 molecular sieve synthesized in Example 7 was calcined at 550°C for 4 h, cooled to room temperature, tableted, crushed, and sieved to select particles of 12–20 mesh for further use. Using methanol as the raw material, a fixed-bed reactor with a diameter of 15 mm was used, and the calcination was carried out at 505°C and a mass hourly space velocity of 3.5 h. -1 The evaluation was carried out under the condition of a pressure of 1.7 MPa, and the yield of ethylene, propylene and butylene reached 96.8%, achieving good technical effects.

[0091] Example 11 The SSP5-2 molecular sieve synthesized in Example 8 was calcined at 550 °C for 4 h, cooled to room temperature, tableted, crushed, and sieved to select particles of 12–20 mesh for further use. Using methanol as the raw material, a fixed-bed reactor with a diameter of 15 mm was used, and the calcination was carried out at 400 °C and a mass hourly space velocity of 0.5 h. -1 The evaluation was carried out under the condition of a pressure of 5.1 MPa, and the yield of ethylene, propylene and butylene reached 92.6%, achieving good technical effects.

[0092] Example 12 The SSP5-3 molecular sieve synthesized in Example 9 was calcined at 550°C for 4 h, cooled to room temperature, tableted, crushed, and sieved to select particles of 12–20 mesh for further use. Using methanol as the raw material, a fixed-bed reactor with a diameter of 15 mm was used, and the calcination was carried out at 600°C and a mass hourly space velocity of 0.1 h. -1 The evaluation was carried out under the condition of a pressure of 0.01 MPa, and the yield of ethylene, propylene and butylene reached 90.9%, achieving good technical effects.

[0093] III. Synthesis and Use of SAPO-17 Molecular Sieves 1. Synthesis of SAPO-17 molecular sieve by SCM-34 molecular sieve Example 13 2.6 g of piperazine (PIP) and 8.5 g of 1,4-dioxane (DOA) were thoroughly stirred at room temperature and then heat-treated at 90°C for 1.0 h to obtain precursor P1. 5.6 g of the SCM-34 molecular sieve prepared in Example 3 and 3.1 g of silica (SiO2) were mixed with 6.9 g of 1,4-dioxane solution and heat-treated at 40°C for 5 h to obtain mixture M1. Precursor P1 was added to mixture M1 under vigorous stirring and stirred for 2.5 h to form a crystallization mixture. The mixture was stirred at 110°C for 0.5 h, then crystallized at 140°C for 1 h, filtered, washed, dried at 120°C for 4 h, and then heated to 500°C and calcined at a constant temperature for 6 h to obtain SAPO-17 molecular sieve, designated STE-1. The XRD pattern is shown in Figure 7, and the SEM pattern is shown in Figure 8.

[0094] Example 14 At room temperature, 666.7 g of 1,10-phenanthroline (1,10-PIH), 731.3 g of piperazine (PIP), and 1285.2 g of 1,2-epoxycyclopentane (CPO) were thoroughly stirred and then heat-treated at 40°C for 5 hours to obtain precursor P2. 239.8 g of SCM-34 molecular sieves prepared in Example 5 were mixed with 139.8 g of 1,2-epoxycyclopentane (CPO) solution and heat-treated at 90°C for 1 hour to obtain mixture M2. Precursor P2 was added to mixture M2 under vigorous stirring, followed by stirring for 4 hours and then a sealed stirring flask at 80°C for 5 hours. The crystallization was then carried out at 130°C for 2 hours. The product was filtered, washed, dried at 100°C for 6 hours, and then heated to 600°C and calcined at this temperature for 4 hours to obtain product STE-2. Its XRD pattern is similar to that in FIG. 7, and its SEM pattern is similar to that in FIG.

[0095] Example 15 Precursor P3 was obtained by thoroughly stirring 0.8 g of cyclohexylamine (HCHA), 33.7 g of piperazine (PIP), 5.5 g of 1,4-dioxane (DOA), and 5.2 g of cyclohexanone (CHO) at room temperature and then heat-treating at 55°C for 4.0 hours. 6.9 g of SCM-34 molecular sieve prepared in Example 6 was mixed with 5.0 g of 1,4-dioxane (DOA) and 5.7 g of cyclohexanone (CHO) solution and heat-treating at 70°C for 2.0 hours to obtain mixture M3. Precursor P3 was added to mixture M3 under vigorous stirring, followed by stirring for 1 hour and then heating at 100°C under sealed stirring for 1 hour. The product was then crystallized at 120°C for 5 hours, filtered, washed, and dried at 80°C for 9 hours. It was then heated to 400°C and calcined at this temperature for 8 hours to obtain a product designated STE-3. Its XRD pattern is similar to that shown in Figure 7, and its SEM pattern is similar to that shown in Figure 8.

[0096] Comparative Example 1 SAPO-17 molecular sieves were prepared according to the synthetic method for SAPO-17 molecular sieves disclosed in CN103922361A. Specifically, aluminum isopropoxide was used as the aluminum source, phosphoric acid as the phosphorus source, silica sol as the silicon source, and cyclohexylamine as the template. 81 g of aluminum isopropoxide was added to 48.9 g of ultrapure water and stirred until uniform. 45.7 g of phosphoric acid (85 wt.%) was added. After stirring for 1 hour, 11.5 mL of cyclohexylamine was added to the mixture. After stirring and aging for 2 hours, 11.9 g of a 30 wt.% aqueous SiO2 solution was added to the reaction mixture. After aging for several hours, the sol was placed in a PTFE-lined stainless steel reactor and crystallized at 200°C for 120 hours to yield short, thick rod-shaped SAPO-17 molecular sieves. The XRD pattern can be seen in FIG. 9, and the SEM pattern can be seen in FIG.

[0097] Comparative Example 2 According to the literature (Tianjin Chemical Industry, 2016, 30(3):17-19.), the synthesis method of SAPO-17 molecular sieve is specifically as follows: Aluminum isopropoxide was used as the aluminum source, phosphoric acid as the phosphorus source, silica sol as the silicon source, and cyclohexylamine as the template. The reaction mixture ratio was 1Al2O3:1P2O5:1CHA:1HF:40H2O, and the amount of solid aluminum source was 0.015 mol. Based on this plan, 3.06 g of aluminum isopropoxide was added to 5.4 g of deionized water and stirred uniformly. After stirring, 1.7 g of phosphoric acid was added and stirred for 1.5 hours. After that, 0.7 g of cyclohexylamine was added to the mixture and stirred and aged for 1.5 hours. After that, 2.25 g of silica sol (40 wt.%) was added to the reaction system and stirred for several hours. After that, the sol was placed in a PTFE-lined stainless steel reactor and crystallized at 200°C for 120 hours to obtain SAPO-17 molecular sieve.

[0098] 2. Use of SAPO-17 molecular sieve (1) Use of SAPO-17 molecular sieves in the reaction of methanol to hydrocarbons Example 16 The STE-1 molecular sieve synthesized in Example 13 was calcined at 550 °C for 4 h, cooled to room temperature, tableted, crushed, and sieved to select particles of 12–20 mesh for further use. Using methanol as the raw material, a fixed-bed reactor with a diameter of 15 mm was used, and the calcination was carried out at 600 °C and a mass hourly space velocity of 4.9 h. -1 The evaluation was carried out under the condition of a pressure of 1.0 MPa, and the methanol conversion rate was 100%, the yield of the products ethylene and propylene reached 78.7%, and the selectivity ratio (ethylene / propylene) was 2.87, achieving good technical results.

[0099] Example 17 The catalyst was prepared using the STE-2 molecular sieve synthesized in Example 14 and the catalyst preparation method in Example 16. Methanol was used as the raw material, and the catalyst was prepared in a fixed-bed reactor with a diameter of 15 mm at 550°C and a mass hourly space velocity of 15 h . -1 The evaluation was carried out under the condition of a pressure of 10 MPa, and the methanol conversion rate was 100%, the yield of the products ethylene and propylene reached 80.8%, and the selectivity ratio (ethylene / propylene) was 2.76, achieving good technical results.

[0100] Example 18 The catalyst was prepared using the STE-3 molecular sieve synthesized in Example 15 and the catalyst preparation method in Example 16. Methanol was used as the raw material, and the catalyst was prepared in a fixed-bed reactor with a diameter of 15 mm at 474°C and a mass space velocity of 7.1 h . -1 The evaluation was carried out under conditions of a pressure of 2.4 MPa, and the methanol conversion rate was 100%, the yield of the products ethylene and propylene reached 84.5%, and the selectivity ratio (ethylene / propylene) was 2.99, achieving good technical results.

[0101] Comparative Example 3 A catalyst was prepared using the SAPO-17 molecular sieve synthesized in Comparative Example 1 and the catalyst preparation method of Example 16. When evaluated according to the method of Example 17, the methanol conversion was 100%, the yield of the products ethylene and propylene reached 33.3%, and the selectivity ratio (ethylene / propylene) was 1.1.

[0102] Comparative Example 4 A catalyst was prepared using the SAPO-17 molecular sieve synthesized in Comparative Example 2 and the catalyst preparation method of Example 16. When evaluated according to the method of Example 18, the methanol conversion was 100%, the yield of the products ethylene and propylene reached 40.1%, and the selectivity ratio (ethylene / propylene) was 1.2.

[0103] (2) Use of SAPO-17 molecular sieves in the synthesis gas to hydrocarbon reaction Example 19 Use of SAPO-17 molecular sieve in synthesis gas to hydrocarbon reactions The STE-1 molecular sieve synthesized in Example 13 was calcined at 550°C for 6 hours, then tableted, crushed, and sieved to select particles of 20-40 mesh. The weight ratio of the catalyst to the filler was ZnCrO x / STE=1.0(ZnCrO x (The term "zinc oxide" refers to a mixture of zinc oxide and chromium oxide, and the oxide-molecular sieve catalyst was prepared for later use.) Using synthesis gas as the raw material, a fixed-bed reactor with a diameter of 15 mm was used. The process conditions were a reaction temperature of 400°C, a pressure of 10 MPa, and a space velocity of 2000 h -1 The synthesis gas composition was H2 / CO = 0.5:1, the CO conversion was 41.9%, and the C2-C4 olefin selectivity was 66.9%, with a selectivity ratio (ethylene / propylene) of 2.61.

[0104] Example 20 Use of SAPO-17 molecular sieve in synthesis gas to hydrocarbon reactions The STE-2 molecular sieve synthesized in Example 14 was used to prepare a catalyst according to the catalyst preparation method of Example 19. The process conditions were a reaction temperature of 375°C, a pressure of 7.5 MPa, and a space velocity of 1000 h -1 The synthesis gas composition was H2 / CO = 0.66:1, the CO conversion was 45.6%, and the C2-C4 olefin selectivity was 75.6%, with a selectivity ratio (ethylene / propylene) of 2.66.

[0105] Example 21 Use of SAPO-17 molecular sieve in synthesis gas to hydrocarbon reactions The STE-3 molecular sieve synthesized in Example 15 was used to prepare a catalyst according to the catalyst preparation method of Example 19. The process conditions were a reaction temperature of 350°C, a pressure of 1.2 MPa, and a space velocity of 500 h -1 The synthesis gas composition was H2 / CO = 0.75:1, the CO conversion was 51.7%, and the C2-C4 olefin selectivity was 85.6%, with a selectivity ratio (ethylene / propylene) of 2.98.

[0106] Comparative Example 5 Use of SAPO-17 molecular sieve in synthesis gas to hydrocarbon reactions The SAPO-17 molecular sieve synthesized in Comparative Example 2 was used to prepare a catalyst according to the catalyst preparation method of Example 20. When evaluated according to the method of Example 20, the CO conversion was 22.3%, with a C2-C4 olefin selectivity of 36.8% and a selectivity ratio (ethylene / propylene) of 1.21.

[0107] As can be seen from the above comparison test, the SAPO-17 molecular sieve prepared in the present invention has higher ethylene and propylene yields and a higher selectivity ratio (ethylene / propylene) in the reaction of methanol conversion to hydrocarbons. The SAPO-17 molecular sieve prepared in the present invention has a higher selectivity ratio (ethylene / propylene) in the reaction of synthesis gas to hydrocarbons. = ~C4 = It has a higher selectivity and selectivity ratio (ethylene / propylene).

Claims

1. An SCM-34 molecular sieve, comprising aluminum, phosphorus, oxygen, and optionally silicon, wherein in an XRD diffraction data of the molecular sieve, the 2θ angle of the most intense peak within a 2θ angle range of 5 to 50° is 7.59±0.2, and the X-ray diffraction pattern of the SCM-34 molecular sieve comprises the X-ray diffraction peaks shown in the following table: 【Table 1】

2. The SCM-34 molecular sieve has the formula "Al ２ O ３ : xSiO ２ :yP ２ 2. The SCM-34 molecular sieve according to claim 1, wherein the molecular sieve has a schematic chemical composition shown in "X" and "Y", where 0≦x≦0.5 and 0.75≦y≦1.5, and the XRD diffraction data of the molecular sieve has a 2θ angle of 7.59±0.2 for the most intense peak within a range of 5 to 50°, and the X-ray diffraction pattern of the SCM-34 molecular sieve includes the X-ray diffraction peaks shown in the following table: 【Table 2】

3. 3. The molecular sieve according to claim 1, wherein the X-ray diffraction pattern of the SCM-34 molecular sieve further comprises the X-ray diffraction peaks shown in the following table: 【Table 3】

4. 4. The molecular sieve according to claim 1, wherein the X-ray diffraction pattern of the SCM-34 molecular sieve further comprises the X-ray diffraction peaks shown in the following table: 【Table 4】

5. A method for preparing an SCM-34 molecular sieve, comprising: subjecting a mixture of an aluminum source, a phosphorus source, organic templates R1 and R2, solvents S1, S2 and S3, and an optionally added silicon source to a crystallization treatment to obtain the SCM-34 molecular sieve; wherein the organic template R1 is selected from one or more of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide, and tetrabutylammonium hydroxide; and the organic template R2 is selected from one or more of imidazole, 2-methylimidazole, 4-methylimidazole, 1-(3-aminopropyl)imidazole, 2-ethyl-4-methylimidazole, pyrrolidine, 1-(3-pyrrolidine)pyrrolidine, N-methylimidazole ...

5. The method for preparing an SCM-34 molecular sieve according to claim 1, wherein the solvent S1 is selected from one or more of an amide group solvent, solvent S2 is selected from one or more of a cyclic organic solvent, and solvent S3 is selected from one or more of water or a lower alcohol, wherein the organic template R1 and the organic template R2 are different organic templates, and solvents S1, S2, and S3 are different solvents.

6. The method according to claim 5, wherein the solvent S1 is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, and N,N-dibutylformamide, the solvent S2 is selected from one or more of 1,4-dioxane, cyclohexane, cyclohexanone, and cyclohexanol, and / or the solvent S3 is selected from one or more of methanol, ethanol, ethylene glycol, butanol, and water.

7. In the mixture, Al ２ O ３ Aluminum source based on SiO ２ a silicon source based on P ２ O ５ The molar composition of the phosphorus source based on the compound (II), the organic template R1 + R2, and the solvent S1 + S2 + S3 is SiO ２ / Al ２ O ３ = 0 to 1, P ２ O ５ / Al ２ O ３ =0.5 to 2, template R1 + R2 / Al ２ O ３ = 1 to 200, solvent S1 + S2 + S3 / Al ２ O ３ The method according to claim 5 or 6, characterized in that:

8. The method according to any one of claims 5 to 7, wherein the molar ratio of the organic template R1 to the organic template R2 is 0.01 to 1:1; and the molar ratio of the solvent S1, the solvent S2, and the solvent S3 is 1:0.01 to 1:1 to 100.

9. 9. The method according to claim 5, wherein the conditions of the crystallization treatment include a crystallization temperature of 120 to 200° C. and a crystallization time of 1 to 5 days.

10. A molecular sieve composition, comprising the molecular sieve according to any one of claims 1 to 4 and a binder.

11. Use of the molecular sieve according to any one of claims 1 to 4 or the molecular sieve prepared by the method according to any one of claims 5 to 9 in the preparation of metal-containing AFI molecular sieves or SAPO-17 molecular sieves.

12. A method for preparing a metal-containing AFI molecular sieve, comprising: using the molecular sieve according to any one of claims 1 to 4 or the molecular sieve prepared by the method according to any one of claims 5 to 9 as a reaction raw material, mixing it with a solvent SI, an organic template R, and optionally a first silicon source to prepare a precursor A; and then mixing the precursor A with a solvent SII, a metal source, and optionally a second silicon source to prepare an AFI molecular sieve; wherein the organic template R is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide, tetrabutylammonium hydroxide, benzyltriethylammonium chloride, benzyltrimethylammonium hydroxide, triethylamine, n-butylamine, di-n-propylamine, diisopropylamine, ethylenediamine, and ethylamine.

13. 1. A method for preparing a SAPO-17 molecular sieve, comprising: 1) mixing an organic template cR with a first organic solvent cS and performing a first heat treatment to obtain a precursor P; 2) Mixing the SCM-34 molecular sieve according to any one of claims 1 to 4, an optionally added silicon source, and a second organic solvent cS, and performing a second heat treatment to obtain a mixture material M; 3) mixing the precursor P obtained in step 1) with the mixture material M obtained in step 2) to form a crystallization mixture; 4) pre-treating the crystallization mixture obtained in step 3) and then carrying out a crystallization reaction to obtain SAPO-17 molecular sieve; The method for preparing SAPO-17 molecular sieve, wherein the organic template cR is at least one of 1,10-phenanthroline, 2,2-bipyridine, 4,4-bipyridine, piperazine, cyclohexylamine, and pyridine.

14. 13. Use of the metal-containing AFI molecular sieve obtained by the process according to claim 12 in the reaction of methanol conversion to hydrocarbons.

15. 14. Use of the SAPO-17 molecular sieve obtained by the process according to claim 13 in a methanol to hydrocarbon reaction or a synthesis gas to hydrocarbon reaction.

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