Composite molecular sieve of TON or MRE configuration molecular sieve and MWW configuration molecular sieve as well as preparation method and application of composite molecular sieve

Abstract

The manufacturing method of the composite molecular sieve comprises the following steps: providing a first molecular sieve comprising a first template agent (such as manufacturing the first molecular sieve comprising the first template agent in the presence of the first template agent), and then producing a second molecular sieve in the presence of a second template agent and the first molecular sieve comprising the first template agent, obtaining the composite molecular sieve wherein the first template agent and the second template agent differ in chemical structure, and the first molecule is screened from at least one of a TON-configuration molecular sieve and a * MRE-configuration molecular sieve (preferably selected from at least one of a ZSM-22 molecular sieve and a ZSM-48 molecular sieve), and the second molecular sieve is an MWW-configuration molecular sieve (preferably an all-silicon MWW-configuration molecular sieve, in particular an all-silicon MCM-22 molecular sieve). The composite molecular sieve provided by the invention can realize the purpose of directionally generating a monomethyl branched chain isomer product, and the quality of the isomer product is obviously improved.

Description

Technical Field

[0001] This invention relates to a method for preparing a dual-microporous composite molecular sieve and its application, specifically to a composite molecular sieve having a TON or MRE configuration molecular sieve and an MWW configuration molecular sieve, its preparation method, and its application in hydroisomerization. Background Technology

[0002] Hydroisomerization of n-alkanes typically employs bifunctional solid catalysts, which include a metal component (transition metal or noble metal) providing addition / dehydrogenation and an acidic component (amorphous oxides, superacids, molecular sieves, etc.) undergoing skeletal isomerization. Compared to amorphous oxides and superacids, molecular sieves exhibit superior performance in shape selectivity, stability, resistance to poisoning, and resistance to carbon deposition. Therefore, isomerization catalysts supported on molecular sieves are widely used.

[0003] There are many reports on the preparation of alkane isomerization catalysts. For example, patent documents such as CN2004138051, CN2005077209, and CN1792451 describe in detail the preparation methods of alkane hydroisomerization catalysts with molecular sieves as supports. US patents US5990371, US5833837, US5817907, US5149421, US5882505, US5135638, US5110445, US4919788, US4419420, US4601993, US4599162, and US4518485 also involve isomerization dewaxing technology. The acidic components used mainly include mordenite, SAPO-11, SAPO-31, SAPO-41, ZSM-23, SSZ-32, and ZSM-48 molecular sieves. Due to their unique pore structure and physicochemical properties, molecular sieves with different structures are suitable for different applications.

[0004] CN201010539097.5 discloses a core-shell structured MFI molecular sieve and its preparation method. The MFI molecular sieve uses a micron-sized Silicalite-1 molecular sieve as the core phase and a nano-sized ZSM-5 molecular sieve as the shell phase, with a shell thickness of 10-50 nm. The preparation method involves first loading an active metal onto the Silicalite-1 molecular sieve via impregnation, and then placing the pure silicon molecular sieve loaded with the active metal into a ZSM-5 molecular sieve growth mother liquor for hydrothermal crystallization. This composite molecular sieve can be applied in petrochemical and other fields, and is an excellent catalytic material, exhibiting good catalytic performance in aromatic alkylation, aromatic isomerization, methane aromatization, and alkane hydroisomerization.

[0005] CN10311000399A discloses a method for preparing mesoporous-microporous composite molecular sieves. The method involves adding hydrothermally treated microporous molecular sieves to a mixture of a silicon source, acid solution, and surfactant. After crystallization, filtration, washing, drying, and calcination, the mesoporous-microporous composite molecular sieve is obtained. This method fully utilizes the non-framework aluminum removed from the microporous molecular sieve, improving the hydrothermal and thermal stability of the composite molecular sieve. Furthermore, it is applied to the catalytic cracking reaction of heavy oil to produce middle distillate oil, improving the conversion rate and selectivity of the reaction.

[0006] CN202110070904.1 discloses a composite molecular sieve catalyst of MCM-41 and SSZ-32, which is a composite molecular sieve of MCM-41 and SSZ-32 supported with noble metals. The composite molecular sieve of MCM-41 and SSZ-32 has a core-shell structure, with SSZ-32 molecular sieve as the core and MCM-41 molecular sieve as the shell. The SSZ-32 molecular sieve has micropores with a pore size of 0.45 × 0.52 nm, and the MCM-41 molecular sieve has mesopores with a pore size of 2-10 nm. The invention also discloses a method for preparing the composite molecular sieve catalyst and its use in increasing the proportion of single-branched products in the hydroisomerization reaction of n-alkanes.

[0007] In the hydroisomerization of long-chain alkanes using molecular sieves, pore structure and acidity determine catalyst performance. According to the pore-key shape-selective isomerization catalysis theory, the hydroisomerization reaction of straight-chain alkanes mainly occurs at the pore openings of the molecular sieve micropores. Although one-dimensional ten-membered ring molecular sieves such as ZSM-22 and SAPO-11 have uniform and well-developed pore structures and high confinement indices, exhibiting good shape selectivity for reactions occurring within the pores, they are often used in small molecule conversion. However, their simple pore structure results in poor adaptability to hydrocarbon (mixture) conversion, and they cannot effectively confine reactions at the pore openings. Especially in the isomerization of large straight-chain alkanes, the lack of confinement at the pore openings easily leads to the formation of multi-branched isomers. The formation of multi-branched isomers not only makes it easier for deep isomerization to affect the properties of the product, but also makes it more prone to cracking reactions, affecting product yield. Currently, mesoporous-microporous composite molecular sieves are mostly used in the catalytic cracking reactions of heavy oils or long-chain macromolecules, exhibiting better catalytic performance compared to single molecular sieves. However, there are fewer reports on this compared to the hydrogenation isomerization of long-chain alkanes. Summary of the Invention

[0008] The inventors of this invention discovered that the surface of a single molecular sieve isomerization catalyst has multiple active sites, but only the active sites at the pore openings are selectively active sites. After a n-alkane undergoes an isomerization reaction at the molecular sieve pore opening to generate a monomethyl branched isomer, due to sufficient reaction space, the monomethyl branched isomer will continue to undergo isomerization reactions to generate a polymethyl branched isomer. Furthermore, when the diffused monomethyl branched isomer contacts other non-selective active sites on the molecular sieve surface, it will also continue to undergo isomerization reactions to generate polymethyl branched isomers.

[0009] The inventors of this invention have also discovered that by covering the non-selective active sites on the surface of the molecular sieve, the occurrence of excessive isomerization can be suppressed; and by setting a local confinement structure at the pore opening of the molecular sieve, the monomethyl isomer is forced to leave immediately after its formation due to steric hindrance, thereby reducing its residence time at the pore opening and preventing further isomerization of the monomethyl branched isomer, which can significantly improve the selectivity of the monomethyl branched isomer.

[0010] The present invention relates in a first aspect to a method for manufacturing a composite molecular sieve, comprising the following steps: providing a first molecular sieve containing a first template agent (e.g., manufacturing the first molecular sieve containing the first template agent in the presence of the first template agent), and then manufacturing a second molecular sieve in the presence of a second template agent and the first molecular sieve containing the first template agent to obtain the composite molecular sieve, wherein the first template agent and the second template agent are chemically different, and the first molecular sieve is selected from at least one of TON-configured molecular sieves and *MRE-configured molecular sieves (preferably selected from at least one of ZSM-22 molecular sieves and ZSM-48 molecular sieves), and the second molecular sieve is an MWW-configured molecular sieve (preferably an all-silica MWW-configured molecular sieve, particularly an all-silica MCM-22 molecular sieve).

[0011] The inventors of this invention have discovered that, in a preferred embodiment, by controlling the amount of MWW-configured molecular sieves, such as all-silica MWW-configured molecular sieves, the all-silica MWW-configured molecular sieves can effectively cover the non-selective active sites on the surface of TON or *MRE-type molecular sieves, without significantly hindering the effective contact of n-alkanes with the pores of the TON or *MRE-configured molecular sieves, thus keeping the pores effectively open. Furthermore, the surface of the all-silica MWW-configured molecular sieve lacks acidic centers, and its pore size is precisely designed to accommodate monomethyl isomers but not polymethyl isomers, allowing the generated monomethyl branched isomers to diffuse rapidly from the pores without further isomerization reactions.

[0012] The present invention relates in a second aspect to a composite molecular sieve, comprising a first molecular sieve and a second molecular sieve covering the surface of the first molecular sieve, wherein the first molecular sieve is selected from at least one of TON-configured molecular sieves and *MRE-configured molecular sieves (preferably selected from at least one of ZSM-22 molecular sieves and ZSM-48 molecular sieves), the second molecular sieve is an MWW-configured molecular sieve (preferably an all-silica MWW-configured molecular sieve, particularly an all-silica MCM-22 molecular sieve), the mass ratio of the first molecular sieve to the second molecular sieve is (60-99):1, preferably (70-99):1, more preferably (80-99):1, and the acidity of the outer surface of the composite molecular sieve is 0.001 mmol / g-0.030 mmol / g (preferably 0.002 mmol / g-0.025 mmol / g).

[0013] In a third aspect, the present invention relates to a hydroisomerization catalyst (preferably a n-alkane hydroisomerization catalyst), comprising the composite molecular sieve of the present invention or a composite molecular sieve manufactured according to the manufacturing method of the present invention, and an active metal component.

[0014] In a fourth aspect, the present invention relates to a hydroisomerization method (e.g., a dewaxing method for lubricating oil fractions), comprising the step of hydroisomerizing n-alkanes (e.g., paraffinic hydrocarbons) in the presence of the hydroisomerization catalyst of the present invention.

[0015] Technical effect

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] According to a preferred embodiment of the present invention, a dual-microporous composite molecular sieve is formed by growing a confined pure silica MWW-type molecular sieve, such as an all-silica MCM-22 molecular sieve, on a host TON or *MRE-type molecular sieve, such as ZSM-22 or ZSM-48. The ZSM-22 or ZSM-48 molecular sieve provides isomerization functionality, while the all-silica MCM-22 molecular sieve provides local confinement functionality. A dual-microporous composite molecular sieve with two different pore sizes, forming a continuous "variable-diameter combined pore" structure, is generated through supramolecular self-assembly using an amphiphilic combined template agent. The pore openings are effectively open to the outside. By combining different pore sizes, the isomerization reaction is confined within the constructed "micro-reaction zone." Straight-chain alkanes enter the isomer molecular sieve and undergo isomerization at the pore openings. After generating a monomethyl branched isomer, further isomerization is prevented due to the pore size constraint of the confined molecular sieve, achieving the goal of directional generation of monomethyl branched isomer products and significantly improving the quality of the isomer products.

[0018] According to a preferred embodiment of the present invention, using all-silica MCM-22 molecular sieve as a confinement agent can reduce the acidity of the outer surface of the host TON or *MRE molecular sieve, such as ZSM-22 or ZSM-48 molecular sieve, deactivate non-selective active sites on the outer surface of the host molecular sieve, inhibit the occurrence of non-ideal reactions, avoid the occurrence of excessive isomerization, improve the selectivity of isomerization reaction, and thus increase the yield of the target product. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0020] Figure 1 This is the XRD pattern of the composite molecular sieve synthesized in Example 1 of the present invention.

[0021] Figure 2 These are the pore size distribution diagrams of the composite molecular sieve and the ZSM-22 molecular sieve in Example 1 of this invention.

[0022] Figure 3 The results are TEM characterization results of the composite molecular sieve synthesized in Example 1 of this invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0024] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0025] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0026] In the context of this invention, all numerical values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numerical value.

[0027] In the context of this invention, "substantially" means that deviations that are acceptable or reasonable to those skilled in the art are permitted, such as deviations within ±2%, ±1%, ±0.5%, or ±0.1%.

[0028] In the context of this invention, the XRD spectrum is measured using a D / max-2500 fully automatic rotating target X-ray diffractometer. The experimental conditions are: Cu target, Kα radiation source, operating voltage 40kV, and tube current 80mA.

[0029] In the context of this invention, the method for measuring the composite structure formed by the first molecular sieve and the second molecular sieve is to use a JEM-2100 high-resolution transmission electron microscope from JEOL Corporation of Japan.

[0030] In the context of this invention, the type of the second molecular sieve is determined by XRD analysis of the powder obtained after lightly grinding the composite molecular sieve and sieving it. Specifically, the light grinding is performed by dry grinding using a mortar and pestle. To facilitate the detachment of the second molecular sieve from the surface of the carrier (first molecular sieve), the entire grinding process is conducted under relatively gentle conditions. The ground composite molecular sieve is then sieved through a mesh of 160 or finer, and the resulting powder (with a higher concentration of the second molecular sieve) is subjected to XRD analysis.

[0031] In the context of this invention, the pore size distribution is measured using an ASAP 2460 physical adsorption instrument via N2 adsorption-desorption method. Before measurement, the sample is activated by vacuuming at 300°C for 4 hours, and the pore size distribution is analyzed using a DFT model.

[0032] In the context of this invention, the average particle size is measured according to GB / T 6288-2021 Method for Determination of Particle Size of Granular Molecular Sieve.

[0033] In the context of this invention, the specific surface area, pore volume, and pore size are measured using an ASAP 2460 physical adsorption instrument via N2 adsorption-desorption method. Before measurement, the sample is activated by vacuuming at 300°C for 4 hours. The specific surface area of ​​the sample is calculated using the BET method, the pore volume is calculated using the BJH model, and the pore size distribution is analyzed using the DFT model.

[0034] In the context of this invention, the template agent content is measured by thermogravimetric analysis, and the weight loss at a temperature above 200°C until the weight loss curve stabilizes is taken as the template agent content of the molecular sieve.

[0035] In the context of this invention, the free water content is measured using a halogen moisture analyzer at a test temperature of 120°C for 10 minutes.

[0036] In the context of this invention, the template agent loss rate is measured by thermogravimetric analysis. The weight loss at temperatures above 200°C until the weight loss curve stabilizes is the template agent content. The template agent loss rate is calculated as: (template agent content in the molecular sieve before washing - template agent content in the molecular sieve after washing) / template agent content in the molecular sieve before washing * 100%.

[0037] In the context of this invention, the method for measuring the amount of acid on the outer surface is to compress the powdered sample into a tablet, evacuate it, heat it to 450°C to degas for 1.5 hours, and then cool it to room temperature. Using 2,6-di-tert-butylpyridine as a probe, the infrared spectrum of its chemical desorption is measured, and the adsorption amount is calculated.

[0038] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this instruction manual are based on weight, and the pressure is gauge pressure.

[0039] In the context of this invention, any two or more embodiments or aspects of this invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of this invention.

[0040] According to one embodiment of the present invention, a method for manufacturing a composite molecular sieve includes the following steps:

[0041] 1) Provide a first molecular sieve containing a first template agent (e.g., manufacture the first molecular sieve containing the first template agent in the presence of the first template agent), then,

[0042] 2) A second molecular sieve is manufactured in the presence of a second template agent and a first molecular sieve containing a first template agent to obtain the composite molecular sieve.

[0043] According to the present invention, "then" means that step 2) must be performed after step 1). Specifically, the second molecular sieve is manufactured only after the first molecular sieve containing the first template agent is manufactured according to step 1). Therefore, according to the present invention, the first molecular sieve containing the first template agent and the second molecular sieve are not manufactured simultaneously. As a case of simultaneous manufacturing, for example, the first molecular sieve and the second molecular sieve can be manufactured simultaneously in the presence of the first template agent and the second template agent.

[0044] According to one embodiment of the present invention, the first molecule is screened from TON or *MRE molecular sieves, such as at least one selected from ZSM-22, KZ-2, NU-10 and ZSM-48 molecular sieves, and the second molecule is screened from at least one MWW molecular sieve, preferably all-silica MWW molecular sieves, especially all-silica MCM-22 molecular sieve.

[0045] According to a preferred embodiment of the present invention, the first molecular sieve is a TON or *MRE configuration molecular sieve, and from the perspective of obtaining a hydroisomerization catalyst with superior performance, ZSM-22 or ZSM-48 molecular sieves are preferred. Furthermore, the second molecular sieve is an MWW configuration molecular sieve, preferably an all-silica MWW (MCM-22) molecular sieve. From the perspective of obtaining a hydroisomerization catalyst with superior performance, the inventors of the present invention have found that, in a preferred embodiment, the pore size and one-dimensional straight channels of ZSM-22 or ZSM-48 molecular sieves are more suitable for long-chain alkane isomerization reactions, while the pore diameter of the all-silica MCM-22 molecular sieve is approximately 0.69 nm, which can restrict monomethyl branched isomers and avoid the formation of multi-branched isomers.

[0046] According to one embodiment of the present invention, in step 1), a silicon source, other first molecular sieve synthesis sources, and water are also present. Here, "other first molecular sieve synthesis sources" refers to all raw materials used to synthesize the first molecular sieve, excluding the silicon source, water, and template agent. These raw materials can be any materials conventionally used by those skilled in the art when manufacturing the relevant molecular sieves, and their amounts are also conventional choices for those skilled in the art; the present invention does not impose any particular limitations on this. Specifically, for TON or *MRE configuration molecular sieves, the other first molecular sieve synthesis sources include an aluminum source and an alkali source, and the silicon source (calculated as SiO2): the aluminum source (calculated as Al2O3): the alkali source (calculated as OH-) -1 (Calculation): The molar ratio of the first template agent to water is SiO2:Al2O3:OH. - R:H₂O = 1:0.01-0.05:0.01-0.35:0.15-1.0:5-50, preferably SiO₂:Al₂O₃:OH - :R:H2O=1:0.02-0.04:0.05-0.25:0.25-0.7:10-40.

[0047] According to one embodiment of the present invention, in step 2), a silicon source, other second molecular sieve synthesis sources, and water are also present. Here, "other second molecular sieve synthesis sources" refers to all raw materials used to synthesize the second molecular sieve, excluding the silicon source, water, and template agent. These raw materials can be any materials conventionally used by those skilled in the art when manufacturing the relevant molecular sieves, and their amounts are also conventional choices for those skilled in the art; the present invention does not impose any particular limitations on this. Specifically, for an MWW-configured molecular sieve, the other second molecular sieve synthesis sources include an alkali source, and the silicon source (calculated as SiO2): the alkali source (calculated as OH...) -1 (Calculation): The molar ratio of the second template agent D and the water is: SiO2:OH -:D:H2O=1:0.1-1.0:0.02-0.5:6-100; Preferred

[0048] SiO2:OH - The ratio of :D:H2O is 1:0.1-0.5:0.05-0.5:10-100, and / or, but the invention is not limited thereto. Preferably, the mass ratio of the first molecular sieve containing the first template agent to the silicon source (calculated as SiO2) in step 2) is (59-99):1, more preferably (69-99):1, and even more preferably (79-99):1.

[0049] The inventors of this invention have discovered that the first molecular sieve provides sufficient active sites for the isomerization reaction of n-alkanes, while the second molecular sieve further confines the alkane. If the amount of the second molecular sieve is too large, it will affect product diffusion; if it is too small, it will not be able to confine the alkane, leading to a decrease in the yield of single-branched alkanes.

[0050] According to one embodiment of the present invention, the average particle size of the first molecular sieve containing the first template agent is 85% or more passing through 60 mesh, preferably 90% or more passing through 100 mesh. The inventors of the present invention have found that a suitable molecular sieve particle size is beneficial for the growth of a second molecular sieve on its surface; when the particle size is too large, it leads to a decrease in specific surface area, a reduction in the number of pores, an increase in free diffusion paths, and a decrease in catalytic activity.

[0051] According to one embodiment of the present invention, the free water content of the first molecular sieve containing the first template agent is no more than 10 wt%, preferably no more than 5 wt%. The inventors of the present invention have found that a lower water content can ensure the particle dispersion of the first molecular sieve. If the water content is too high, it will cause the dispersibility of the first molecular sieve to decrease, resulting in a viscous state, which will affect the growth of the second molecular sieve on its surface.

[0052] According to one embodiment of the present invention, based on a total weight of 100 wt% of the first molecular sieve containing the first template agent, the content of the first template agent is 2 wt%-50 wt%, preferably 3 wt%-40 wt%.

[0053] According to one embodiment of the present invention, after the first molecular sieve containing the first template agent is washed twice with deionized water at room temperature, the loss rate of the first template agent is less than 10 wt% (preferably less than 5 wt% or less than 2 wt%). According to the present invention, the first template agent is substantially entirely embedded within the pores of the first molecular sieve during its manufacturing process, and the interaction between the template agent and the first molecular sieve is not simply physical adsorption or physical mixing; therefore, the washing loss rate is very small.

[0054] According to one embodiment of the present invention, the first template agent and the second template agent are different in chemical structure. Preferably, the first template agent and the second template agent have similar polarity. According to the present invention, "similar polarity" means that the difference in molecular polarity between the first template agent and the second template agent is small. Specifically, if the two template agent molecules contain the same type and similar number of polar functional groups and the polar functional groups are relatively symmetrically positioned in the molecule, especially ammonium groups or substituted ammonium groups, or if the two template agents are mutually soluble or have a small difference in solubility in the same solvent (e.g., a difference of less than 20%), then they can be considered to have a small difference in molecular polarity.

[0055] The inventors of this invention have discovered that the first template agent and the second template agent have similar polarities, which attracts them to each other. Furthermore, if both template agents contain nitrogen-containing functional groups, the two template agents can bond with each other after forming hydrogen bonds through the nitrogen-containing functional groups.

[0056] The inventors of this invention have also discovered that two template agents combined with each other self-assemble to form a composite template agent, which, after secondary crystallization, yields dual microporous materials with different crystal phases. While "coating" the precursor of a confined molecular sieve, such as a MWW molecular sieve, onto the surface of a host molecular sieve, such as a TON or *MRE-configured molecular sieve, the composite template agent is used to keep the "variable diameter composite channel" channels unobstructed, thereby effectively opening the pores of the obtained composite molecular sieve to the outside.

[0057] According to one embodiment of the present invention, the first template agent can be used to synthesize the first molecular sieve. According to the present invention, as long as hydrogen bonds can be formed between the first template agent and the second template agent, those skilled in the art can freely choose the first template agent within the range conventionally known in the art, without any particular limitation. Specifically, for TON or *MRE configuration molecular sieves, the first template agent R is selected from at least one of 1-butylamine, diethylamine, ethylenediamine, 1,6-hexanediamine, 1-ethylpyridine bromide, 1,5-bis(N-methylimidazolium)pentane, 1,6-bis(N-methylimidazolium)hexane, tetramethylammonium chloride, 1,8-octanediamine, hexamethylammonium bromide, hexamethylammonium hydroxide, diethyltriamine, triethyltetraamine, tetraethyltetraamine, and allyltrimethylammonium chloride, preferably 1,6-hexanediamine.

[0058] According to one embodiment of the present invention, the second template agent can be used to synthesize the second molecular sieve. According to the present invention, as long as the second template agent can form hydrogen bonds with the first template agent, those skilled in the art can freely choose the second template agent within the range conventionally known in the art, without any particular limitation. Specifically, for MWW-configured molecular sieves, the second template agent D is selected from at least one of hexamethyleneimine, ethylenediamine, piperidine, perpiperazine, N,N,N-trimethyl-1-adamantylammonium hydroxide, cyclohexylamine, N',N',N'-hexamethyl-1,5-pentanediammonium salt, and N,N,N',N'-tetraisopropyl-1,5-pentanediammonium hydrogen salt, preferably ethylenediamine.

[0059] According to one embodiment of the present invention, step 1) includes the following steps:

[0060] 1-1) A first mixture is formed by mixing a silicon source, other first molecular sieve synthesis sources, a first template agent, and water.

[0061] 1-2) Crystallize the first mixture to generate the first molecular sieve containing the first template agent.

[0062] 1-3) Separate the first molecular sieve containing the first template agent (preferably, after optional washing and / or optional filtration, dry (especially heat drying) the first molecular sieve containing the first template agent).

[0063] According to one embodiment of the present invention, in step 1-2), the crystallization conditions include: crystallization pressure ranging from atmospheric pressure to the system's autogenous pressure, presence or absence of seed crystals, crystallization temperature of 145℃-200℃ (preferably 155℃-190℃), and crystallization time of 20h-150h (preferably 25h-120h). The crystallization method is static or dynamic crystallization, preferably dynamic crystallization.

[0064] According to one embodiment of the present invention, in steps 1-3), the drying conditions include: a drying temperature of 60℃-120℃, preferably 65℃-110℃, and a drying time of 5h-20h, preferably 8h-15h.

[0065] According to one embodiment of the present invention, in steps 1-3), the drying conditions include: drying in an oil bath or a water bath, preferably drying in an oil bath.

[0066] According to one embodiment of the present invention, after steps 1-3), the first molecular sieve containing the first template agent is further pulverized (e.g., ground) to an average particle size of 85% or more passing through 60 mesh, preferably 90% or more passing through 100 mesh.

[0067] According to one embodiment of the present invention, the manufacturing method does not include a step capable of removing part or all of the first template agent from the first molecular sieve containing the first template agent. Preferably, according to the present invention, the first molecular sieve containing the first template agent is substantially not removed after manufacturing. The inventors of the present invention have found that if the first molecular sieve does not contain a template agent, or if a first molecular sieve without a template agent is added during the synthesis of the second molecular sieve, and both the first and second template agents are added simultaneously, this situation leads to the inability to form a continuous pore structure between the first and second molecular sieves during the synthesis of the composite molecular sieve, severely restricting the diffusion of reactants and products. Since calcination can remove the template agent, according to a preferred embodiment of the present invention, step 1) does not include a calcination step.

[0068] According to one embodiment of the present invention, step 2) includes the following steps:

[0069] 2-1) A second mixture is formed by mixing a silicon source, other second molecular sieve synthesis sources, a second template agent, and water.

[0070] 2-2) Mix the first molecular sieve containing the first template agent with the second mixture to obtain a composite mixture.

[0071] 2-3) Optionally, after drying the composite mixture, crystallize the composite mixture to generate the composite molecular sieve.

[0072] 2-4) After optional washing and / or optional filtration, the composite molecular sieve is dried.

[0073] According to one embodiment of the present invention, in step 2-2), the second mixture is coated (e.g., sprayed) onto the first molecular sieve containing the first template agent in a finely granulated form.

[0074] According to one embodiment of the present invention, in step 2-2), the morphological integrity (particularly the bulk structure or pore structure) of the first molecular sieve containing the first template agent is substantially maintained after the mixing. In other words, the morphological integrity (particularly the bulk structure or pore structure) of the first molecular sieve containing the first template agent is substantially maintained under the manufacturing conditions of the second molecular sieve. Therefore, according to the present invention, the second molecular sieve is grown in situ on the first molecular sieve containing the first template agent. The inventors of the present invention have found that maintaining the morphological integrity of the first molecular sieve is beneficial to the permeability of the pore structure of the composite molecular sieve and also provides suitable active sites and reaction sites for isomerization reactions, which is beneficial to the diffusion of reactants and products. If the morphological integrity of the first molecular sieve is severely damaged, the second molecular sieve will be unable to grow on its surface, seriously affecting the confinement effect.

[0075] According to one embodiment of the present invention, in step 2-3), when the composite mixture has been dried, the crystallization conditions include: crystallization pressure from atmospheric pressure to the system's autogenous pressure, water vapor concentration of 20%-70%, preferably 30%-50%, crystallization temperature of 130℃-220℃, preferably 140℃-200℃, and crystallization time of 24h-120h, preferably 36h-96h.

[0076] According to one embodiment of the present invention, in steps 2-3), drying is an optional step, but drying is preferred. The inventors of the present invention have discovered that the drying process allows the second molecular sieve precursor to form a dry gel on the surface of the first molecular sieve, which is more conducive to the subsequent crystallization process where the molecular sieve grows on its surface. Therefore, the drying conditions include: a drying temperature of 60℃-150℃, preferably 80℃-130℃, and a drying time of 1.0h-20h, preferably 2.0h-15h.

[0077] According to one embodiment of the present invention, in steps 2-4), the drying conditions include: a drying temperature of 80℃-150℃, preferably 85℃-130℃, and a drying time of 5h-20h, preferably 8h-15h.

[0078] According to one embodiment of the present invention, the manufacturing method further includes a step of calcining the composite molecular sieve after steps 2-4), wherein the calcination conditions include: calcination temperature of 400℃-650℃ (preferably 450℃-600℃) under an oxygen-containing atmosphere, and calcination time of 5h-20h (preferably 8h-15h).

[0079] According to one embodiment of the present invention, in step 1), the first molecular sieve containing the first template agent is substantially not removed after manufacturing.

[0080] According to one embodiment of the present invention, in step 2), the morphological integrity (particularly the bulk structure or pore structure) of the first molecular sieve containing the first template agent is substantially maintained under the manufacturing conditions of the second molecular sieve.

[0081] According to one embodiment of the present invention, in step 2), the second molecular sieve is grown in situ on the first molecular sieve containing the first template agent.

[0082] According to a preferred embodiment of the present invention, a composite molecular sieve is provided, comprising a first molecular sieve and a second molecular sieve. Here, the first molecular sieve is a TON and *MRE configuration molecular sieve (preferably ZSM-22 and ZSM-48 molecular sieves), and the second molecular sieve is an MWW configuration molecular sieve (preferably all-silica MCM-22 molecular sieve).

[0083] In the composite molecular sieve of the present invention, the first molecular sieve has a complete, smooth crystal structure, at least a portion of which is covered by a dense layer of the second molecular sieve, and preferably, the second molecular sieve densely covers substantially the entire surface of the first molecular sieve. The inventors of the present invention have discovered that as the coverage of the second molecular sieve on the surface of the first molecular sieve increases, the composite molecular sieve increasingly exhibits the surface properties of the second molecular sieve and increasingly loses the surface properties of the first molecular sieve, such as the amount of acid on the outer surface. In contrast, composite molecular sieves formed by directly coating the second molecular sieve onto the first molecular sieve according to the proportions specified in the present invention, or by simply physically mixing the two, still exhibit the surface properties of the first molecular sieve (e.g., the amount of acid on the outer surface); however, because the second molecular sieve occupies a relatively low proportion in the entire composite molecular sieve, its surface properties are difficult to measure.

[0084] According to one embodiment of the present invention, the acid content of the outer surface of the composite molecular sieve is 0.001 mmol / g to 0.030 mmol / g (preferably 0.002 mmol / g to 0.025 mmol / g). For comparison, the acid content of the outer surface of ZSM-22 or ZSM-48 molecular sieves is generally 0.03 mmol / g to 0.13 mmol / g, and the acid content of the outer surface of all-silica MWW molecular sieves is generally 0 mmol / g.

[0085] According to the present invention, the mass ratio of the first molecular sieve to the second molecular sieve is (60-99):1, preferably (70-99):1, and more preferably (80-99):1. The inventors of the present invention have discovered that the composite molecular sieve formed by the present invention mainly consists of the second molecular sieve grown on the surface of the first molecular sieve. If the content of the second molecular sieve is too high, it will lead to an excessively high content of inactive components in the composite molecular sieve, resulting in a decrease in catalyst activity. Furthermore, it will cover the pore structure of the first molecular sieve, affecting the mass transfer process of the reactant products.

[0086] According to the present invention, since the second molecular sieve accounts for a lower proportion in the entire composite molecular sieve, its contribution to the XRD pattern is smaller. Therefore, the XRD pattern of the composite molecular sieve is substantially the same as that of the first molecular sieve. If the relative intensity of the strongest characteristic diffraction peak in the XRD pattern is designated as 100, then vw = very weak (>0 to <10); w = weak (10 to ≤20); m = moderate (>20 to ≤40); s = strong (>40 to ≤60); vs = very strong (>60 to ≤100). Here, "substantially the same" means that the composite molecular sieve is consistent with the first molecular sieve at least on all characteristic diffraction peaks with relative intensities of s to vs (preferably m to vs). In other words, the composite molecular sieve substantially does not show characteristic diffraction peaks with relative intensities of s to vs associated with the second molecular sieve (when the second molecular sieve is measured alone), unless such characteristic diffraction peaks are shared by both the first and second molecular sieves. Based on the surface properties described above in this specification, and without any theoretical limitations, the inventors of this invention believe that the composite molecular sieve of this invention substantially exhibits the characteristics of the first molecular sieve in terms of bulk properties and substantially exhibits the characteristics of the second molecular sieve in terms of surface properties.

[0087] The inventors of this invention discovered that, while both the first molecular sieve and the composite molecular sieve exhibit two distribution peaks within their micropore size distribution range—one for small pores and one for larger pores—the number of pores differs significantly between them. Compared to the first molecular sieve, the composite molecular sieve shows a decrease in the number of small-pore channels and an increase in the number of larger-pore channels. Without being limited by any theoretical constraints, the inventors believe this is because, when the second molecular sieve with a larger pore size is assembled onto the first molecular sieve, it covers a portion of the small-pore channels on the surface of the first molecular sieve, thus reducing the number of small-pore channels, albeit by a small margin. This phenomenon also indicates that the channels of the first and second molecular sieves are essentially interconnected. More specifically, the composite molecular sieve has a bimodal pore distribution, and the most probable pore sizes of the composite molecular sieve's channel distribution are 0.54 nm–0.62 nm (preferably about 0.58 nm) and 0.67 nm–0.72 nm (preferably about 0.69 nm), respectively. Preferably, the composite molecular sieve has pores with a most probable pore size of 0.54 nm to 0.62 nm accounting for more than 80% (preferably around 90%) of the total pore volume.

[0088] According to one embodiment of the present invention, the average particle size of the first molecular sieve is 85% or more passing through 60 mesh (preferably 90% or more passing through 100 mesh).

[0089] According to one embodiment of the present invention, the composite molecular sieve has a BET specific surface area of ​​150 m². 2 / g-350m 2 / g (preferably 150m) 2 / g-300m 2 / g), with a pore volume of 0.10ml / g-0.55ml / g (preferably 0.15ml / g-0.50ml / g).

[0090] According to one embodiment of the present invention, the composite molecular sieve can be manufactured according to any of the manufacturing methods described above or below in this specification.

[0091] According to one embodiment of the present invention, a hydroisomerization catalyst (preferably a n-alkane hydroisomerization catalyst) is provided, comprising the composite molecular sieve and active metal component described in any of the foregoing or hereinafter of this specification.

[0092] According to one embodiment of the present invention, based on a total weight of 100 wt% of the hydroisomerization catalyst, the content (dry basis) of the composite molecular sieve is 1 wt%-80 wt% (preferably 10 wt%-70 wt%, more preferably 20 wt%-60 wt%), and the content (based on metal element) of the active metal component is 0.01 wt%-10 wt% (preferably 0.05 wt%-8.0 wt%, more preferably 0.1 wt%-5.0 wt%).

[0093] According to one embodiment of the present invention, the active metal component is selected from at least one noble metal element of Group VIII of the periodic table, preferably at least one of Pt and Pd, especially Pt.

[0094] According to one embodiment of the present invention, a hydroisomerization method (such as a dewaxing method for lubricating oil fractions) is provided, comprising the step of hydroisomerizing n-alkanes (such as paraffinic hydrocarbons) in the presence of a hydroisomerization catalyst as described in any of the foregoing or following claims of this specification. It is particularly suitable for dewaxing lubricating oil fractions, offering advantages such as high yield of liquid products, a significant increase in the content of middle distillate oils, low gas production, and a high viscosity index of the lubricating oil base oil.

[0095] According to one embodiment of the present invention, the conditions for the hydroisomerization reaction include: a reaction temperature of 300°C-500°C, a reaction pressure of 0.5 MPa-10 MPa, and a volume hourly space velocity of 0.5 h⁻¹. -1 -4.0h -1 The hydrogen-to-oil volume ratio is 500:1-1400:1.

[0096] According to one embodiment of the present invention, a molecular sieve precursor is provided, comprising a molecular sieve and a template agent, wherein the average particle size of the precursor is more than 80% passing through 60 mesh, preferably more than 90% passing through 100 mesh, and the free water content is not more than 10 wt%, preferably not more than 5 wt%.

[0097] According to the present invention, the template agent R is selected from at least one of 1-butylamine, diethylamine, ethylenediamine, 1,6-hexanediamine, 1-ethylpyridine bromide, 1,5-bis(N-methylimidazolium)pentane, 1,6-bis(N-methylimidazolium)hexane, tetramethylammonium chloride, 1,8-octanediamine, hexamethylammonium bromide, hexamethylammonium hydroxide, diethyltriamine, triethyltetraamine, tetraethyltetraamine, and allyltrimethylammonium chloride, preferably 1,6-hexanediamine. The molecular sieve is a TON or *MRET configuration molecular sieve (preferably ZSM-22 and ZSM-48 molecular sieves).

[0098] According to one embodiment of the present invention, after the precursor is washed twice with deionized water at room temperature, the loss rate of the template agent is less than 10 wt% (preferably less than 5 wt% or less than 2 wt%).

[0099] According to one embodiment of the present invention, the content of the template agent is 3wt%-38wt%, preferably 6wt%-33wt%, based on a total weight of 100wt% of the precursor.

[0100] Example

[0101] The present invention will be further described in detail below through examples, but the present invention is not limited to these examples. Unless otherwise specified, the contents in the following examples or comparative examples are all weight percentages.

[0102] In the following examples and comparative examples, the performance evaluation of the catalyst isomerization reaction was carried out using n-dodecane as a model compound. The catalyst was pre-reduced before feeding to convert the noble metal on the catalyst into a reduced state. The reduction conditions were as follows: in the presence of hydrogen, at a temperature of 450°C, a pressure of 4.0 MPa, and a time of 6 hours. The evaluation reaction conditions were as follows: in the presence of hydrogen, at a temperature of 300°C-500°C and a pressure of 1.0 MPa-10 MPa.

[0103] Synthesis of TON-type molecular sieves

[0104] The ZSM-22 molecular sieves used in the examples were synthesized with different Si / Al ratios using the same method as provided in CN201811434178.

[0105] The ZSM-48 molecular sieves used in the examples were synthesized with different Si / Al ratios using the same method as provided in US6923949A.

[0106] Example 1

[0107] 1) Add 15.7g of potassium hydroxide and 6.5g of aluminum sulfate to 370g of deionized water and stir to dissolve. After complete dissolution, add 55.7g of 1,6-hexanediamine and stir for 10 minutes. Then add 5g of ZSM-22 seed crystals and 320g of silica sol (mass fraction of silica sol is 28%). Continue stirring at room temperature until a homogeneous initial gel mixture is formed. Place the initial gel in a self-generated pressure crystallization vessel and crystallize at 160℃ for 35 hours. After crystallization, dry the crystallized product in an oil bath at 80℃ for 5 hours to obtain the main molecular sieve ZSM-22, Si / Al = 75, designated A-1.

[0108] The main molecular sieve A-1 is not calcined, and its average particle size is more than 95% passing through 100 mesh, free water content is 3.5wt%, template agent content is 18wt%, and template agent loss rate is less than 4.5wt%.

[0109] 2) Add 20g of silica, 10g of sodium hydroxide and 37.5g of ethylenediamine to 500g of deionized water and stir at 50℃ until a uniform gel mixture is formed. Then spray it onto the main molecular sieve A-1 and dry it at 80℃ for 2.5h to obtain a composite molecular sieve dry gel. Then crystallize it at 170℃ for 8h under the action of water vapor, dry it at 100℃ for 4h and calcine it at 550℃ for 3h to obtain a double microporous composite molecular sieve F-1, which is a composite molecular sieve formed by covering the surface of ZSM-22 molecular sieve with all-silica MCM-22 molecular sieve.

[0110] 3) Take 50g of the prepared dual-microporous composite molecular sieve F-1 (dry basis, the same below) and 35g of pseudoboehmite (dry basis) and mix them thoroughly. Add 1.3mL of concentrated nitric acid (mass fraction of 65%) and an appropriate amount of water, knead thoroughly, and then extrude into strips. Then, impregnate the strips with noble metal Pt using the impregnation method, with the Pt loading being 0.30wt% of the support. After drying at 110℃ for 3h and calcining at 480℃ for 3.5h, the catalyst E-1 of this invention is obtained. The evaluation results of the catalyst are shown in Table 1.

[0111] Figure 1 The XRD characterization results show that composite molecular sieve 1 is the composite molecular sieve prepared in this invention, and composite molecular sieve 2 is the composite molecular sieve after light grinding. Both mainly exhibit the characteristic diffraction peaks of ZSM-22 molecular sieve. The composite molecular sieve is identical to the first molecular sieve ZSM-22 in all characteristic diffraction peaks with relative intensities from w to vs. Further comparative studies revealed that composite molecular sieve 2 exhibits weaker characteristic diffraction peaks of MCM-22 molecular sieve, thus confirming that the second molecular sieve is of type MCM-22.

[0112] Figure 2 The results show the pore size distribution of the composite molecular sieve and the first molecular sieve. It can be seen that the composite molecular sieve has two distribution peaks: small pore size and large pore size. However, there is a significant difference in the number of pores between the two. Compared with the first molecular sieve, the increase in the number of large pores indicates the introduction of the second molecular sieve. In contrast, the number of small pores in the composite molecular sieve decreases, but the decrease is small, indicating that the pores of the first and second molecular sieves are basically interconnected.

[0113] TEM images revealed that the dual-microporous composite molecular sieve comprises a first molecular sieve (ZSM-22 molecular sieve) and a second molecular sieve (all-silica MCM-22 molecular sieve) covering the surface of the first molecular sieve. Figure 3 As shown. According to Figure 3 It can be seen that a dense layer of crystalline material covers the original crystal surface of the first molecular sieve ZSM-22, and a clear boundary between the two can be seen when magnified.

[0114] Measurements showed that the mass ratio of the first to the second molecular sieve in the dual-microporous composite molecular sieve was 90:1. The channels of the first and second molecular sieves were essentially interconnected, and the XRD pattern of the composite molecular sieve was substantially the same as that of the first molecular sieve. The composite molecular sieve exhibited a bimodal pore distribution, with the most probable pore diameters being 0.58 nm and 0.69 nm, respectively. Pores with a most probable diameter of 0.58 nm accounted for 96% of the total pore volume. The BET specific surface area of ​​the composite molecular sieve was 225 m². 2 / g, pore volume is 0.18ml / g, and surface acidity is 0.0075mmol / g.

[0115] As a control, the main molecular sieve A-1 was dried at 60℃ for 2 hours, then treated with steam at 160℃ for 40 hours, dried at 110℃ for 4 hours, and calcined at 500℃ for 3 hours. Measurements showed that the surface acidity of the main molecular sieve A-1 after steam treatment was 0.082 mmol / g, which is significantly higher than that of the composite molecular sieve.

[0116] Example 2

[0117] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, with the mass ratio of the first molecular sieve to the second molecular sieve being 90:1. The differences were: the amount of aluminum sulfate added was different, the SiO2 / Al2O3 ratio of ZSM-22 was 55, and silica sol replaced silica. The dual-microporous composite molecular sieve had a composite structure similar to that in Example 1, with an external surface acidity of 0.0015 mmol / g. The catalyst was designated E-2, and the evaluation results are shown in Table 1.

[0118] Example 3

[0119] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that 1,6-hexanediamine was substituted with 1,8-octanediamine, the mass ratio of the first molecular sieve to the second molecular sieve was 85:1, and the dual-microporous composite molecular sieve had a composite structure similar to that in Example 1, with an external surface acidity of 0.0021 mmol / g. The catalyst was designated E-3, and the evaluation results are shown in Table 1.

[0120] Example 4

[0121] The composition and physicochemical properties of the catalyst are shown in Table 1, and the evaluation results of the catalyst are shown in Table 2.

[0122] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the mass ratio of the first molecular sieve to the second molecular sieve was 96:1, and the dual-microporous composite molecular sieve had a composite structure similar to that in Example 1, with an external surface acidity of 0.0018 mmol / g. The catalyst was designated E-4, and the evaluation results are shown in Table 1.

[0123] Example 5

[0124] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: boehmite was added during the synthesis of the second molecular sieve to obtain a composite molecular sieve consisting of an aluminum-containing MCM-22 molecular sieve covered with a ZSM-22 molecular sieve. The dual-microporous composite molecular sieve has a composite structure similar to that in Example 1, with an outer surface acidity of 0.025 mmol / g. The catalyst was named E-5, and the evaluation results of the catalyst are shown in Table 1.

[0125] Example 6

[0126] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the mass ratio of the silicon source (calculated as SiO2) added to the synthesis of the second molecular sieve to the first molecular sieve containing the first template agent was 1:45. The dual microporous composite molecular sieve had a composite structure similar to that in Example 1, with an outer surface acidity of 0.0033 mmol / g. The catalyst was named E-6, and the evaluation results of the catalyst are shown in Table 1.

[0127] Example 7

[0128] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the mass ratio of the silicon source (calculated as SiO2) added to the synthesis of the second molecular sieve to the first molecular sieve containing the first template agent was 1:65. The dual microporous composite molecular sieve had a composite structure similar to that in Example 1, with an outer surface acidity of 0.0025 mmol / g. The catalyst was named E-7, and the evaluation results of the catalyst are shown in Table 1.

[0129] Example 8

[0130] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the mass ratio of the silicon source (calculated as SiO2) added to the synthesis of the second molecular sieve to the first molecular sieve containing the first template agent was 1:120. The dual microporous composite molecular sieve had a composite structure similar to that in Example 1, with an outer surface acidity of 0.0014 mmol / g. The catalyst was named E-8, and the evaluation results of the catalyst are shown in Table 1.

[0131] Example 9

[0132] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: the average particle size of the first molecular sieve containing the first template agent was 85% passing through 55 mesh, the dual microporous composite molecular sieve had a composite structure similar to that in Example 1, the acidity of the outer surface was 0.0078 mmol / g, the catalyst was named E-9, and the evaluation results of the catalyst are shown in Table 1.

[0133] Example 10

[0134] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the free water content of the first molecular sieve containing the first template agent was 18 wt%, the dual microporous composite molecular sieve had a composite structure similar to that in Example 1, the acidity of the outer surface was 0.020 mmol / g, the catalyst was named E-10, and the evaluation results of the catalyst are shown in Table 1.

[0135] Example 11

[0136] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: after the crystallization of the first molecular sieve, the product was dried by ordinary drying at a temperature of 100°C for 4 hours. The dual-microporous composite molecular sieve had a composite structure similar to that in Example 1, with an outer surface acidity of 0.008 mmol / g. The catalyst was named E-11, and the evaluation results of the catalyst are shown in Table 1.

[0137] Example 12

[0138] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst are the same as in Example 1, except that the raw materials for the synthesis of the second molecular sieve are mixed and sprayed onto the main molecular sieve A-1 without drying. The dual microporous composite molecular sieve has a composite structure similar to that in Example 1, with an outer surface acidity of 0.015 mmol / g. The catalyst is named E-12, and the evaluation results of the catalyst are shown in Table 1.

[0139] Example 13

[0140] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: 0.5 g of sodium hydroxide was added to the raw material for the synthesis of the second molecular sieve, causing some of the first molecular sieve to be dissolved and destroyed. The resulting dual-microporous composite molecular sieve had a similar composite structure to that in Example 1, with an external surface acidity of 0.028 mmol / g. The catalyst was named E-13. The evaluation results of the catalyst are shown in Table 1.

[0141] Example 14

[0142] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that no water vapor participated in the reaction during the crystallization of the second molecular sieve. The dual microporous composite molecular sieve had a composite structure similar to that in Example 1, with an outer surface acidity of 0.026 mmol / g. The catalyst was named E-14, and the evaluation results of the catalyst are shown in Table 1.

[0143] Example 15

[0144] 1) Mix 1.5g sodium hydroxide, 0.8g aluminum sulfate, 20g 1,6-hexanediamine, 90g silica sol (mass fraction 25.9%), and 400g of other ingredients thoroughly. After aging at room temperature for 2 hours, place the mixture in a self-generating pressure crystallization reactor and crystallize at 180℃ for 40 hours. After crystallization, dry the crystallized product in an oil bath at 75℃ for 6 hours to obtain the main molecular sieve ZSM-48, with Si / Al = 35, designated A-2. The main molecular sieve A-2 is not calcined and has an average particle size of over 95% passing through a 100-mesh sieve, a free water content of 4.0wt%, a template agent content of 19wt%, and a template agent loss rate of less than 4.5wt%.

[0145] 2) Mix 37.5g ethylenediamine, 0.1g sodium hydroxide, 20g silica and 500g water evenly, then spray it onto the main molecular sieve A-2. After drying at 80℃ for 2.5h, a composite molecular sieve dry gel is obtained. Then, it is crystallized at 170℃ for 18h under the action of water vapor, dried at 100℃ for 4h and calcined at 550℃ for 3h to obtain a double microporous composite molecular sieve F-2, which is a composite molecular sieve formed by covering the surface of ZSM-48 molecular sieve with all-silica MCM-22 molecular sieve.

[0146] 3) Take 50g of the prepared dual-microporous composite molecular sieve F-2 (dry basis, the same below) and 35g of pseudoboehmite (dry basis) and mix them thoroughly. Add 1.3mL of concentrated nitric acid (mass fraction of 65%) and an appropriate amount of water, knead thoroughly, and then extrude into strips. Then, impregnate the strips with precious metal Pt using the impregnation method. The Pt loading is 0.30wt% of the support. After drying at 110℃ for 3h and calcining at 500℃ for 3.5h, the catalyst E-15 of this invention is obtained. The evaluation results of the catalyst are shown in Table 1.

[0147] Measurements showed that the mass ratio of the first to the second molecular sieve in the dual-microporous composite molecular sieve was 90:1. The channels of the first and second molecular sieves were essentially interconnected, and the XRD pattern of the composite molecular sieve was substantially the same as that of the first molecular sieve. The composite molecular sieve exhibited a bimodal pore distribution, with the most probable pore diameters being 0.58 nm and 0.69 nm, respectively. Pores with a most probable diameter of 0.58 nm accounted for 96% of the total pore volume. The BET specific surface area of ​​the composite molecular sieve was 214 m². 2 / g, pore volume is 0.21ml / g, and surface acidity is 0.0075mmol / g.

[0148] Example 16

[0149] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 15, except that piperidine replaced ethylenediamine, the mass ratio of the first molecular sieve to the second molecular sieve was 90:1, and the dual-microporous composite molecular sieve had a composite structure similar to that in Example 15, with an external surface acidity of 0.0021 mmol / g. The catalyst was designated E-16, and the evaluation results are shown in Table 1.

[0150] Example 17

[0151] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 15, except that the mass ratio of the first molecular sieve to the second molecular sieve was 80:1, and the dual-microporous composite molecular sieve had a composite structure similar to that in Example 15, with an external surface acidity of 0.045 mmol / g. The catalyst was named E-17, and the evaluation results of the catalyst are shown in Table 1.

[0152] Example 18

[0153] 1) 11.77g sodium hydroxide, 7.9g aluminum sulfate, 92.7g diethyltriamine, 200g silica sol (30% by mass) and 576g were mixed evenly and aged at room temperature for 2 hours. The mixture was then placed in a self-generating pressure crystallization reactor and crystallized at 175℃ for 96 hours. After crystallization, the crystallized product was dried in an oil bath at 75℃ for 6 hours to obtain the main molecular sieve NU-10, with a Si / Al ratio of 33, designated A-2. The main molecular sieve A-3 was not calcined and had an average particle size of over 95% passing through a 100-mesh sieve, a free water content of 4.0wt%, a template agent content of 19wt%, and a template agent loss rate of less than 4.5wt%.

[0154] 2) Mix 37.5g ethylenediamine, 0.1g sodium hydroxide, 20g silica and 500g water evenly, then spray it onto the main molecular sieve A-2. After drying at 80℃ for 2.5h, a composite molecular sieve dry gel is obtained. Then, it is crystallized at 170℃ for 18h under the action of water vapor, dried at 100℃ for 4h and calcined at 550℃ for 3h to obtain a double microporous composite molecular sieve F-3, which is a composite molecular sieve formed by covering the surface of NU-10 molecular sieve with all-silica MCM-22 molecular sieve.

[0155] 3) Take 50g of the prepared dual-microporous composite molecular sieve F-3 (dry basis, the same below) and 35g of pseudoboehmite (dry basis) and mix thoroughly. Add 1.3mL of concentrated nitric acid (mass fraction of 65%) and an appropriate amount of water, knead thoroughly, and then extrude into strips. Then, impregnate with noble metal Pt using the impregnation method, with the Pt loading being 0.30wt% of the support. After drying at 110℃ for 3h and calcining at 500℃ for 3.5h, the catalyst E-18 of this invention is obtained. The evaluation results of the catalyst are shown in Table 1.

[0156] Measurements showed that the mass ratio of the first to the second molecular sieve in the dual-microporous composite molecular sieve was 90:1. The channels of the first and second molecular sieves were essentially interconnected, and the XRD pattern of the composite molecular sieve was substantially the same as that of the first molecular sieve. The composite molecular sieve exhibited a bimodal pore distribution, with the most probable pore diameters being 0.58 nm and 0.69 nm, respectively. Pores with a most probable diameter of 0.58 nm accounted for 95% of the total pore volume. The BET specific surface area of ​​the composite molecular sieve was 204 m². 2 / g, pore volume is 0.21ml / g, and surface acidity is 0.008mmol / g.

[0157] Example 19

[0158] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 18, except that diethylamine replaced diethyltriamine, the mass ratio of the first molecular sieve to the second molecular sieve was 90:1, and the dual-microporous composite molecular sieve had a composite structure similar to that of Example 18, with an external surface acidity of 0.0031 mmol / g. The catalyst was designated E-19, and the evaluation results are shown in Table 1.

[0159] Example 20

[0160] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 15, except that the mass ratio of the first molecular sieve to the second molecular sieve was 80:1, and the dual-microporous composite molecular sieve had a composite structure similar to that in Example 18, with an external surface acidity of 0.050 mmol / g. The catalyst was named E-20, and the evaluation results of the catalyst are shown in Table 1.

[0161] Comparative Example 1

[0162] The preparation of comparative catalyst C-1 in this invention

[0163] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: the first molecular sieve was directly ZSM-22 molecular sieve (SiO2 / Al2O3 ratio of 75) after calcination and removal of the template agent. The surface acidity of the resulting composite molecular sieve was 0.062 mmol / g. The catalyst was named C-1. The evaluation results of the catalyst are shown in Table 1.

[0164] Comparative Example 2

[0165] The preparation of catalyst C-2 in this invention

[0166] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that 37.5 g of ethylenediamine 4 was added to the raw material for synthesizing the first molecular sieve, crystallized at 160 °C for 28 h, washed, dried and calcined to obtain the composite molecular sieve. The surface acidity of the obtained composite molecular sieve was 0.085 mmol / g, and the catalyst was named C-2. The evaluation results of the catalyst are shown in Table 1.

[0167] Comparative Example 3

[0168] The preparation of the comparative catalyst C-3 in this invention

[0169] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: the first molecular sieve was synthesized as MCM-22 molecular sieve (SiO2 / Al2O3 = 80), and the second molecular sieve was synthesized as ZSM-22 molecular sieve (SiO2 / Al2O3 = 70). The resulting composite molecular sieve was formed by covering the surface of ZSM-22 molecular sieve with MCM-22 molecular sieve. The surface acidity of the obtained composite molecular sieve was 0.089 mmol / g. The catalyst was named C-3, and the evaluation results of the catalyst are shown in Table 1.

[0170] Comparative Example 4

[0171] The preparation of the comparative catalyst C-4 in this invention

[0172] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that the first molecular sieve ZSM-22 was dried and then calcined at a temperature of 450℃ for 3 hours. The resulting composite molecular sieve had an outer surface acidity of 0.036 mmol / g. The catalyst was named C-4, and the evaluation results of the catalyst are shown in Table 1.

[0173] Comparative Example 5

[0174] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 1, except that: the second molecular sieve, all-silica MCM-22, was synthesized first, and then coated onto the first molecular sieve at a mass ratio of 1:90. The resulting composite molecular sieve had an outer surface acidity of 0.047 mmol / g, and the catalyst was named C-5. The evaluation results of the catalyst are shown in Table 1.

[0175] Comparative Example 6

[0176] The synthesis of the composite molecular sieve and the preparation and evaluation of the catalyst were the same as in Example 15, except that: the first molecular sieve was directly ZSM-48 molecular sieve (SiO2 / Al2O3 ratio of 35) after calcination and removal of the template agent. The surface acidity of the resulting composite molecular sieve was 0.042 mmol / g. The catalyst was named C-6. The evaluation results of the catalyst are shown in Table 1.

[0177] Using n-dodecane as a model compound, the hydroisomerization reaction performance of the catalysts prepared in the examples and comparative examples was evaluated. The catalysts were pre-reduced before feeding to convert the noble metals on the catalysts into a reduced state. The reduction conditions were as follows: in the presence of hydrogen, temperature 300℃-500℃, pressure 0.5MPa-10MPa, time 1 hour-12 hours. The evaluation results are shown in Table 1.

[0178] Table 1 Results of the hydroisomerization reaction of n-dodecane over a catalyst

[0179] Catalyst number Reaction temperature / ℃ n-Dodecane conversion rate / % Dodecyl monomethyl isomer selectivity E-1 287 90.23 85.90 E-2 286 89.33 85.29 E-3 294 90.33 84.58 E-4 287 89.63 84.48 E-5 284 89.63 78.08 E-6 296 91.53 78.49 E-7 293 90.33 81.23 E-8 286 91.13 78.90 E-9 288 90.13 80.93 E-10 288 90.33 79.40 E-11 288 90.03 81.94 E-12 288 89.73 82.45 E-13 295 90.73 77.07 E-14 295 89.93 80.52 E-15 292 90.53 82.55 E-16 290 89.15 81.97 E-17 296 89.93 82.04 E-18 289 90.01 75.92 E-19 287 89.93 73.84 E-20 292 90.23 74.51 C-1 285 90.63 69.55 C-2 262 89.23 67.52 C-3 295 88.73 48.94 C-4 290 91.43 70.98 C-5 289 90.83 70.16 C-6 295 89.43 68.95

[0180] The evaluation results in Table 1 show that, compared with the comparative catalyst, the catalyst provided by this invention has a higher conversion rate and selectivity for isododecane in the hydroisomerization reaction of n-dodecane.

Claims

1. A method for manufacturing a composite molecular sieve, comprising the following steps: 1) Provide a first molecular sieve containing a first template agent (e.g., manufacture the first molecular sieve containing the first template agent in the presence of the first template agent), then 2) A second molecular sieve is manufactured in the presence of a second template agent and the first molecular sieve containing the first template agent to obtain the composite molecular sieve. The first template agent and the second template agent are different in chemical structure, and the first molecule is selected from at least one of TON configuration molecular sieve and *MRE configuration molecular sieve (preferably selected from at least one of ZSM-22 molecular sieve and ZSM-48 molecular sieve), and the second molecular sieve is MWW configuration molecular sieve (preferably all-silica MWW configuration molecular sieve, especially all-silica MCM-22 molecular sieve).

2. The manufacturing method of claim 1, wherein in step 1), a silicon source, an aluminum source, an alkali source, and water are further present, wherein the silicon source (calculated as SiO2): the aluminum source (calculated as Al2O3): the alkali source (calculated as OH-) -1 (Calculated): The molar ratio of the first template agent R and the water is SiO2:Al2O3:OH. - R:H₂O = 1:0.01-0.05: 0.01-0.35: 0.15-1.0: 5-50, preferably SiO₂:Al₂O₃:OH - :R:H2O=1: 0.02-0.04: 0.05-0.25: 0.25-0.7: 10-40, and / or, in step 2), a silicon source, an alkali source, and water are also present, wherein the silicon source (as SiO2): the alkali source (as OH) -1 (Calculated): The molar ratio of the second template agent D and the water is SiO2:OH - :D:H2O=1:0.1-1.0:0.02-0.5:6-100; preferably SiO2:OH - :D:H2O=1:0.1-0.5:0.05-0.5:10-100, and / or, the mass ratio of the first molecular sieve containing the first template agent to the silicon source (calculated as SiO2) in step 2) is (59-99):1, preferably (69-99):1, and more preferably (79-99):

1.

3. The manufacturing method according to claim 1, wherein in step 2), the average particle size of the first molecular sieve containing the first template agent is 85% or more passing through 60 mesh, preferably 90% or more passing through 100 mesh, and / or, the free water content of the first molecular sieve containing the first template agent is not more than 10%, preferably not more than 5%.

4. The manufacturing method according to claim 1, wherein in step 2), based on the total weight of the first molecular sieve containing the first template agent as 100wt%, the content of the first template agent is 2-50wt%, preferably 3-40wt%, and / or, after the first molecular sieve containing the first template agent is washed twice with deionized water at room temperature, the loss rate of the first template agent is less than 10% (preferably less than 5% or less than 2%).

5. The manufacturing method of claim 1, wherein the first template agent and the second template agent have similar polarity and are able to form hydrogen bonds with each other in the presence of water, and / or, the first template agent can be used to synthesize the first molecular sieve, and / or, the second template agent can be used to synthesize the second molecular sieve.

6. The manufacturing method of claim 1, wherein the first template agent is selected from at least one of 1-butylamine, diethylamine, ethylenediamine, 1,6-hexanediamine, 1-ethylpyridine bromide, 1,5-bis(N-methylimidazolium)pentane, 1,6-bis(N-methylimidazolium)hexane, tetramethylammonium chloride, 1,8-octanediamine, hexamethylammonium bromide, hexamethylammonium hydroxide, diethyltriamine, triethyltetraamine, tetraethyltetraamine, and allyltrimethylammonium chloride, preferably 1,6-hexanediamine, and / or the second template agent is selected from at least one of hexamethyleneimine, ethylenediamine, piperidine, perpiperazine, N,N,N-trimethyl-1-adamantylammonium hydroxide, cyclohexylamine, N',N',N'-hexamethyl-1,5-pentanediammonium salt, N,N,N',N'-tetraisopropyl-1,5-pentanediammonium hydrogen salt, preferably ethylenediamine.

7. The manufacturing method of claim 1, wherein step 1) comprises the following steps: 1-1) A first mixture is formed by mixing a silicon source, an aluminum source, an alkali source, a first template agent, and water. 1-2) Crystallize the first mixture to generate the first molecular sieve containing the first template agent. 1-3) Separate the first molecular sieve containing the first template agent, preferably, after optional washing and / or optional filtration, dry (especially heat drying) the first molecular sieve containing the first template agent.

8. The manufacturing method of claim 7, wherein in steps 1-2), the crystallization conditions include: The crystallization pressure ranges from atmospheric pressure to the system's self-generated pressure, with or without seed crystals. The crystallization temperature is 145-200℃, preferably 155-190℃, and the crystallization time is 20-150 hours, preferably 25-120 hours.

9. The manufacturing method of claim 7, wherein in steps 1-3), the drying conditions include: The drying temperature is 60-120℃, preferably 65-110℃, and the drying time is 5-20 hours, preferably 8-15 hours.

10. The manufacturing method according to claim 7, wherein in steps 1-3), the heating and drying is performed by heating and drying in an oil bath.

11. The manufacturing method of claim 7 further includes, after steps 1-3), pulverizing (e.g., grinding) the first molecular sieve containing the first template agent until an average particle size of 85% or more passes through 60 mesh, preferably 90% or more passes through 100 mesh.

12. The manufacturing method of claim 1, excluding the step of removing part or all of the first template agent from the first molecular sieve containing the first template agent, and / or wherein step 1) does not include a calcination step.

13. The manufacturing method of claim 1, wherein step 2) comprises the following steps: 2-1) A second mixture is formed by mixing a silicon source, an alkaline source, a second template agent, and water. 2-2) The first molecular sieve containing the first template agent is mixed with the second mixture to obtain a composite mixture. 2-3) Optionally, after drying the composite mixture, the composite mixture is crystallized to generate the composite molecular sieve. 2-4) After optional washing and / or optional filtration, the composite molecular sieve is dried and calcined to obtain the composite molecular sieve.

14. The manufacturing method of claim 13, wherein in step 2-2), the first molecular sieve containing the first template agent is finely coated (e.g., sprayed) with the second mixture, and / or the morphological integrity (particularly the bulk structure or pore structure) of the first molecular sieve containing the first template agent is substantially maintained after the mixing.

15. The manufacturing method of claim 13, wherein in steps 2-3), the crystallization conditions include: The crystallization pressure is from atmospheric pressure to the system's self-generated pressure, the water vapor concentration is 20%-70%, preferably 30%-50%, the crystallization temperature is 130-220℃, preferably 140-200℃, and the crystallization time is 24-120 hours, preferably 36-96 hours.

16. The manufacturing method of claim 13, wherein in steps 2-4), the drying conditions include: The drying temperature is 80-150℃, preferably 85-130℃, and the drying time is 5-20 hours, preferably 8-15 hours.

17. The manufacturing method of claim 13, wherein in steps 2-4), the calcination conditions include: Under an oxygen-containing atmosphere, the calcination temperature is 400-650℃, preferably 450-600℃, and the calcination time is 5-20 hours, preferably 8-15 hours.

18. The manufacturing method of claim 1, wherein in step 1), the first molecular sieve containing the first template agent is substantially not removed after manufacturing.

19. The manufacturing method of claim 1, wherein in step 2), the morphological integrity (particularly the bulk structure or pore structure) of the first molecular sieve containing the first template agent is substantially maintained under the manufacturing conditions of the second molecular sieve, and / or, in step 2), the second molecular sieve is grown in situ on the first molecular sieve containing the first template agent.

20. A composite molecular sieve comprising a first molecular sieve and a second molecular sieve covering the surface of the first molecular sieve, wherein the first molecular sieve is selected from at least one of TON-configured molecular sieves and *MRE-configured molecular sieves (preferably selected from at least one of ZSM-22 molecular sieves and ZSM-48 molecular sieves), the second molecular sieve is an MWW-configured molecular sieve (preferably an all-silica MWW-configured molecular sieve, particularly an all-silica MCM-22 molecular sieve), the mass ratio of the first molecular sieve to the second molecular sieve is (60-99):1, preferably (70-99):1, more preferably (80-99):1, and the outer surface acidity of the composite molecular sieve is 0.001 mmol / g-0.030 mmol / g (preferably 0.002 mmol / g-0.025 mmol / g).

21. The composite molecular sieve of claim 20, wherein the first molecular sieve and the second molecular sieve are substantially interconnected in terms of pores, and / or the XRD pattern of the composite molecular sieve is substantially the same as the XRD pattern of the first molecular sieve.

22. The composite molecular sieve of claim 20, wherein the composite molecular sieve has a bimodal pore distribution, and / or the most probable pore sizes of the pore distribution of the composite molecular sieve are 0.54-0.62 nm (preferably about 0.58 nm) and 0.67-0.72 nm (preferably about 0.69 nm), and / or the pores of the composite molecular sieve with the most probable pore size of 0.54-0.62 nm account for more than 80% (preferably about 90%) of the total pore volume.

23. The composite molecular sieve of claim 20, wherein the BET specific surface area of ​​the composite molecular sieve is 150-350 m². 2 / g, preferably with a BET specific surface area of ​​150-300 m² 2 / g, with a pore volume of 0.10-0.55ml / g, preferably 0.15-0.50ml / g.

24. The composite molecular sieve of claim 20 can be manufactured according to the manufacturing method of any one of claims 1-19.

25. A hydroisomerization catalyst (preferably a n-alkane hydroisomerization catalyst), comprising the composite molecular sieve of claim 20 or the composite molecular sieve manufactured according to the manufacturing method of claim 1, and an active metal component.

26. The hydroisomerization catalyst of claim 25, wherein, based on 100 wt% of the total weight of the hydroisomerization catalyst, the content (dry basis) of the composite molecular sieve is 1-80 wt% (preferably 10-70 wt%, more preferably 20-60 wt%), and the content (based on metal element) of the active metal component is 0.01-10 wt% (preferably 0.05-8.0 wt%, more preferably 0.1-5.0 wt%).

27. A hydroisomerization method (e.g., a dewaxing method for lubricating oil fractions), comprising the step of hydroisomerizing n-alkanes (e.g., paraffinic hydrocarbons) in the presence of the hydroisomerization catalyst of claim 22.

28. The hydroisomerization method of claim 27, wherein the conditions for the hydroisomerization reaction include: In the presence of hydrogen, the reaction temperature is 300℃-500℃, the reaction pressure is 1.0MPa-10MPa, and the volume hourly space velocity is 0.5h⁻¹. -1 -4.0h -1 The hydrogen-to-oil volume ratio is 500:1-1400:1.

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