A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor

Abstract

The present invention provides a method for preparing an efficient and environmentally friendly ZSM-35 molecular sieve by recycling a synthetic mother liquor, and belongs to the technical field of molecular sieve preparation. The method of the present invention first recycles and concentrates the ZSM-35 molecular sieve synthesis mother liquor to obtain a circulating mother liquor, and then mixes a silicon source, an aluminum source, an alkali source, a template agent, and water, and adds the circulating mother liquor to prepare an H-type ZSM-35 molecular sieve, reducing the grain size of the molecular sieve. The present invention recycles the mother liquor and as one of the key raw materials, reinvests it in the preparation process of the ZSM-35 molecular sieve, realizes the recycling of resources and the continuous production of molecular sieves. The method of the present invention can improve the utilization efficiency of raw materials, reduce production costs, and significantly reduce the burden on the environment, and promote the development of green chemical synthesis technology.

Description

Technical Field

[0001] The invention relates to the technical field of molecular sieve preparation, and in particular to a method for preparing a highly efficient and environmentally friendly ZSM-35 molecular sieve by recycling a synthetic mother liquor. Background Art

[0002] ZSM-35 molecular sieve is a microporous material with a unique pore structure and excellent catalytic performance. It is widely used in the fields of petrochemicals, environmental protection, fine chemicals, etc. In its synthesis process, a large amount of silicon source, aluminum source and organic template are usually used. Only part of these raw materials are converted into molecular sieves during the reaction, and the rest remain in the mother liquor. In traditional methods, these mother liquors are often treated as waste liquids, which not only wastes resources, but also may pollute the environment.

[0003] With the increasing attention paid to sustainable development and environmental protection around the world, how to efficiently utilize resources and reduce environmental pollution has become the focus of scientific research and industry. In this context, the recycling of ZSM-35 molecular sieve mother liquor has become an important research direction.

[0004] The crystal size of molecular sieve has a great influence on its catalytic activity. Large crystal molecular sieve usually means a smaller surface area per unit mass, which reduces the chance of contact between the catalyst and the reactant, thereby reducing the catalytic efficiency; and the diffusion path of the molecules inside the catalyst becomes longer, which will increase the diffusion resistance and affect the transmission speed of the reactants and products in the molecular sieve pores, thereby affecting the catalytic performance. Large crystal molecular sieves may also contain fewer active sites, resulting in a catalytic effect that is not as good as that of small crystal molecular sieves. Summary of the invention

[0005] In view of this, the present invention provides a method for preparing efficient and environmentally friendly ZSM-35 molecular sieve by recycling synthesis mother liquor. The method recovers and reuses the synthesis mother liquor, uses it as one of the key raw materials, and re-invests it in the preparation process of ZSM-35 molecular sieve, which can not only reduce the consumption of raw materials and reduce production costs, but also effectively reduce waste liquid discharge, which is in line with the concepts of green chemistry and sustainable development. At the same time, the prepared ZSM-35 molecular sieve has a smaller grain size.

[0006] The method for preparing a high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling a synthetic mother liquor provided by the present invention comprises the following steps:

[0007] (1) filtering the ZSM-35 molecular sieve synthesis mother liquor to remove insoluble solid impurities therein, and then distilling and concentrating it to obtain a circulating mother liquor;

[0008] (2) mixing a silicon source, an aluminum source, an alkali source, a template agent, and water to obtain a raw material mixed solution, adding a circulating mother solution to obtain a molecular sieve precursor mixture;

[0009] (3) transferring the molecular sieve precursor mixture of step (2) into a crystallization kettle, crystallizing at 150-190° C. for 24-96 hours, washing with water to neutrality after crystallization, and then drying and calcining to obtain Na-type ZSM-35 molecular sieve;

[0010] (4) exchanging the Na-type ZSM-35 molecular sieve of step (3) with a 3-10 wt% ammonium salt aqueous solution at 40-90° C. for 1-6 h, washing with water until neutral, drying and calcining to obtain an H-type ZSM-35 molecular sieve.

[0011] Preferably, the filtering medium in step (1) is one of filter paper, filter membrane and filter cloth, and the filtering accuracy of the filtering medium is 20-50 μm.

[0012] Preferably, the circulating mother liquor in step (1) is a mother liquor having a template content of 5 to 15% by mass.

[0013] More preferably, the circulating mother liquor comprises the following components by mass fraction: 5-15% template, 1-3% Si, 0.05-1.5% Al, 0.01-0.05% Na, and the remainder H 2 O. The Si, Al and Na all exist in the form of ions.

[0014] Preferably, the silicon source described in step (2) is one or two of silica sol, C-type silica gel, and white carbon black; the aluminum source is one or two of sodium aluminate, aluminum sulfate, aluminum nitrate, pseudo-boehmite, and aluminum chloride; the alkali source is sodium hydroxide; and the template agent is one or two of pyrrolidine, ethylenediamine, cyclohexylamine, and pyridine.

[0015] Preferably, the amount of the circulating mother liquor added in step (2) is 10 to 30% of the mass of the raw material mixture.

[0016] Preferably, the molar ratio of the silicon source, aluminum source, alkali source, template and water in step (2) is SiO 2 :Al 2 O 3 :Na 2 O: Template: H 2 O=30~120:1:1.0~10.0:5.0~40.0:400~2500.

[0017] Preferably, the drying conditions in step (3) are drying at 100-150° C. for 6-10 hours; and the roasting conditions are roasting at 450-600° C. for 4-8 hours.

[0018] Preferably, the drying conditions in step (4) are drying at 100-150° C. for 6-10 hours; and the calcining conditions are calcining at 450-600° C. for 4-8 hours.

[0019] The present invention also provides an H-type ZSM-35 molecular sieve prepared by the above method, wherein the H-type ZSM-35 molecular sieve is a small-grain laminated H-type ZSM-35 molecular sieve.

[0020] Preferably, the grain size of the H-type ZSM-35 molecular sieve is 100 to 450 nm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The mother liquor of ZSM-35 molecular sieve contains a large amount of silicon aluminum source and organic template. These components can be reused in the synthesis of molecular sieve after proper treatment. This recycling method greatly improves the efficiency of resource utilization and reduces the waste of raw materials;

[0023] (2) By recycling the mother liquor, the production cost can be reduced, which is of great significance to improving the economic benefits and market competitiveness of the enterprise;

[0024] (3) Direct discharge of mother liquor will cause serious pollution to the environment. Through recycling, the discharge of waste liquid can be significantly reduced, the burden on the environment can be reduced, and the requirements of environmental protection can be met;

[0025] (4) By adding recycled mother liquor to the synthesis, the grain size can be effectively reduced, providing an experimental scheme for the preparation of small-grain ZSM-35 molecular sieves. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the XRD pattern of 1# ZSM-35 molecular sieve in Example 1;

[0027] Figure 2 This is the SEM image of the 1# ZSM-35 molecular sieve of Example 1;

[0028] Figure 3 This is the SEM image of 2#ZSM-35 molecular sieve of Example 2;

[0029] Figure 4 This is the SEM image of 3# ZSM-35 molecular sieve of Example 3;

[0030] Figure 5 This is the SEM image of 4# ZSM-35 molecular sieve of Example 4;

[0031] Figure 6 This is the SEM image of 5# ZSM-35 molecular sieve of Example 5;

[0032] Figure 7 This is the SEM image of 6# ZSM-35 molecular sieve of Comparative Example 1. DETAILED DESCRIPTION

[0033] The present invention provides a method for preparing a highly efficient and environmentally friendly ZSM-35 molecular sieve by recycling a synthetic mother liquor, the steps of which are as follows:

[0034] (1) filtering the ZSM-35 molecular sieve synthesis mother liquor to remove insoluble solid impurities therein, and then distilling and concentrating it to obtain a circulating mother liquor;

[0035] (2) mixing a silicon source, an aluminum source, an alkali source, a template agent, and water to obtain a raw material mixed solution, adding a circulating mother solution to obtain a molecular sieve precursor mixture;

[0036] (3) transferring the molecular sieve precursor mixture of step (2) into a crystallization kettle, crystallizing at 150-190° C. for 24-96 hours, washing with water to neutrality after crystallization, and then drying and calcining to obtain Na-type ZSM-35 molecular sieve;

[0037] (4) exchanging the Na-type ZSM-35 molecular sieve of step (3) with a 3-10 wt% ammonium salt aqueous solution at 40-90° C. for 1-6 h, washing with water until neutral, drying and calcining to obtain an H-type ZSM-35 molecular sieve.

[0038] Preferably, the filtering medium in step (1) is one of filter paper, filter membrane and filter cloth, and the filtering accuracy of the filtering medium is 30 μm.

[0039] Preferably, the circulating mother liquor in step (1) is a mother liquor having a template content of 5 to 15% by mass;

[0040] In a specific embodiment of the present invention, the specific components of the circulating mother liquor are:

[0041] 10% template, 1.5% Si, 1% Al, 0.03% Na, and the balance H 2 O, the Si, Al, and Na all exist in ionic form; the template component in the circulating mother liquor is the same as the template added in step (2).

[0042] Preferably, the silicon source described in step (2) is one or two of silica sol, C-type silica gel, and white carbon black; the aluminum source is one or two of sodium aluminate, aluminum sulfate, aluminum nitrate, pseudo-boehmite, and aluminum chloride; the alkali source is sodium hydroxide; and the template agent is one or two of pyrrolidine, ethylenediamine, cyclohexylamine, and pyridine.

[0043] Preferably, the amount of circulating mother liquor added in step (2) is 10 to 30% of the mass of the raw material mixed liquor.

[0044] Preferably, the molar ratio of the silicon source, aluminum source, alkali source, template and water in step (2) is SiO 2 :Al 2 O 3 :Na 2 O: Template: H 2 O=30~120:1:1.0~10.0:5.0~40.0:400~2500.

[0045] Preferably, the drying conditions in step (3) are drying at 100-150° C. for 6-10 hours; and the roasting conditions are roasting at 450-600° C. for 4-8 hours.

[0046] Preferably, the drying conditions in step (4) are drying at 100-150° C. for 6-10 hours; and the calcining conditions are calcining at 450-600° C. for 4-8 hours.

[0047] The present invention also provides an H-type ZSM-35 molecular sieve prepared by the above method, wherein the H-type ZSM-35 molecular sieve is a small-grain laminated H-type ZSM-35 molecular sieve.

[0048] Preferably, the grain size of the H-type ZSM-35 molecular sieve is 100 to 450 nm.

[0049] The present invention will be further described below in conjunction with the embodiments.

[0050] Example 1

[0051] A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, the steps are as follows:

[0052] (1) The ZSM-35 molecular sieve synthesis mother liquor was filtered using filter paper (30 μm) to remove insoluble solid impurities in the mother liquor, and then concentrated by distillation to obtain a circulating mother liquor, wherein the composition of the circulating mother liquor is: 10% pyridine, 1.5% Si, 1% Al, 0.03% Na, and the remainder H 2 O.

[0053] (2) 42.07 g of silica sol, 0.59 g of sodium aluminate, 0.56 g of sodium hydroxide, 2.88 g of pyridine, and 33.90 g of deionized water were uniformly mixed to obtain a raw material mixed solution, and a circulating mother liquor of 20% by mass of the raw material mixed solution was added to obtain a molecular sieve precursor mixture;

[0054] (3) The molecular sieve precursor mixture of step (2) was transferred into a crystallization kettle, crystallized at 170° C. for 50 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0055] (4) The Na-type ZSM-35 molecular sieve of step (3) was exchanged with a 5 wt% ammonium salt aqueous solution at 50°C for 3 hours, washed with water until neutral, dried at 100°C for 6 hours, and calcined at 500°C for 4 hours to obtain a 1#H-type ZSM-35 molecular sieve. The XRD pattern of the 1#ZSM-35 molecular sieve is shown in FIG. Figure 1 , SEM pictures are as follows Figure 2 , grain size is 100~300nm.

[0056] Example 2

[0057] A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, the steps are as follows:

[0058] (1) The ZSM-35 molecular sieve synthesis mother liquor was filtered using filter paper (30 μm) to remove insoluble solid impurities in the mother liquor, and then concentrated by distillation to obtain a circulating mother liquor, wherein the composition of the circulating mother liquor is: 10% pyridine, 1.5% Si, 1% Al, 0.03% Na, and the remainder H 2 O;

[0059] (2) 13.32 g of type C silica gel, 0.59 g of sodium aluminate, 0.69 g of sodium hydroxide, 2.88 g of pyridine, and 62.53 g of deionized water were uniformly mixed to obtain a raw material mixed solution, and a circulating mother liquor of 20% by mass of the raw material mixed solution was added to obtain a molecular sieve precursor mixture;

[0060] (3) The molecular sieve precursor mixture of step (2) was transferred into a crystallization kettle, crystallized at 170° C. for 50 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0061] (4) The Na-type ZSM-35 molecular sieve of step (3) was exchanged with a 5 wt % ammonium salt aqueous solution at 50° C. for 3 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 500° C. for 4 h to obtain a 2#H-type ZSM-35 molecular sieve. The SEM image of the 2#ZSM-35 molecular sieve of Example 2 is as follows: Figure 3 , the grain size is 120~350nm.

[0062] Example 3

[0063] A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, the steps are as follows:

[0064] (1) The ZSM-35 molecular sieve synthesis mother liquor was filtered using filter paper (30 μm) to remove insoluble solid impurities in the mother liquor, and then concentrated by distillation to obtain a circulating mother liquor, wherein the composition of the circulating mother liquor is: 10% pyridine, 1.5% Si, 1% Al, 0.03% Na, and the remainder H 2 O;

[0065] (2) 42.07 g of silica sol, 1.39 g of aluminum sulfate, 0.80 g of sodium hydroxide, 2.88 g of pyridine, and 32.86 g of deionized water were uniformly mixed to obtain a raw material mixed solution, and a circulating mother liquor of 20% by mass of the raw material mixed solution was added to obtain a molecular sieve precursor mixture;

[0066] (3) The molecular sieve precursor mixture of step (2) was transferred into a crystallization kettle, crystallized at 170° C. for 50 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0067] (4) The Na-type ZSM-35 molecular sieve of step (3) was exchanged with a 5 wt % ammonium salt aqueous solution at 50° C. for 3 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 500° C. for 4 h to obtain a 3#H-type ZSM-35 molecular sieve. The SEM image of the 5#ZSM-35 molecular sieve of Example 3 is as follows: Figure 4 , the grain size is 110~380nm.

[0068] Example 4

[0069] A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, the steps are as follows:

[0070] (1) The ZSM-35 molecular sieve synthesis mother liquor was filtered using filter paper (30 μm) to remove insoluble solid impurities in the mother liquor, and then concentrated by distillation to obtain a circulating mother liquor, wherein the composition of the circulating mother liquor is: 10% ethylenediamine, 1.5% Si, 1% Al, 0.03% Na, and the remainder H 2 O;

[0071] (2) 42.40 g of silica sol, 0.59 g of sodium aluminate, 0.56 g of sodium hydroxide, 2.12 g of ethylenediamine, and 34.32 g of deionized water were uniformly mixed to obtain a raw material mixed solution, and a circulating mother liquor of 20% by mass of the raw material mixed solution was added to obtain a molecular sieve precursor mixture;

[0072] (3) The molecular sieve precursor mixture of step (2) was transferred into a crystallization kettle, crystallized at 170° C. for 50 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0073] (4) The Na-type ZSM-35 molecular sieve of step (3) was exchanged with a 5 wt % ammonium salt aqueous solution at 50° C. for 3 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 500° C. for 4 h to obtain a 4#H-type ZSM-35 molecular sieve. The SEM image of the 5#ZSM-35 molecular sieve of Example 4 is as follows: Figure 5 , the grain size is 200~420nm.

[0074] Example 5

[0075] A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, the steps are as follows:

[0076] (1) The ZSM-35 molecular sieve synthesis mother liquor was filtered using filter paper (30 μm) to remove insoluble solid impurities in the mother liquor, and then concentrated by distillation to obtain a circulating mother liquor, wherein the composition of the circulating mother liquor is: 10% pyridine, 1.5% Si, 1% Al, 0.03% Na, and the remainder H 2 O;

[0077] (2) 42.07 g of silica sol, 0.59 g of sodium aluminate, 0.56 g of sodium hydroxide, 3.18 g of pyridine, and 33.60 g of deionized water were uniformly mixed to obtain a raw material mixed solution, and a circulating mother liquor of 17% by mass of the raw material mixed solution was added to obtain a molecular sieve precursor mixture;

[0078] (3) The molecular sieve precursor mixture of step (2) was transferred into a crystallization kettle, crystallized at 170° C. for 50 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0079] (4) The Na-type ZSM-35 molecular sieve of step (3) was exchanged with a 5 wt % ammonium salt aqueous solution at 50° C. for 3 h, washed with water until neutral, dried at 100° C. for 6 h, and calcined at 500° C. for 4 h to obtain a 5#H-type ZSM-35 molecular sieve. The SEM image of the 5#ZSM-35 molecular sieve of Example 5 is as follows: Figure 6 , the grain size is 205~440nm.

[0080] Comparative Example 1

[0081] The difference between Comparative Example 1 and Example 1 is that the H-type ZSM-35 molecular sieve is prepared without adding the circulating mother liquid, and the steps are as follows:

[0082] (1) 42.07 g of silica sol, 0.59 g of sodium aluminate, 0.56 g of sodium hydroxide, 4.88 g of pyridine, and 51.90 g of deionized water were mixed to obtain a molecular sieve precursor mixture;

[0083] (2) transferring the molecular sieve precursor mixture of step (1) into a crystallization kettle, crystallizing at 170° C. for 50 h, washing with water until neutral after crystallization, drying at 100° C. for 6 h, and calcining at 550° C. for 4 h to obtain Na-type ZSM-35 molecular sieve;

[0084] (3) The Na-type ZSM-35 molecular sieve of step (2) was exchanged with a 5 wt% ammonium salt aqueous solution at 50°C for 3 hours, washed with water until neutral, dried at 100°C for 6 hours, and calcined at 500°C for 4 hours to obtain a 6#H-type ZSM-35 molecular sieve. The SEM image of the 6#ZSM-35 molecular sieve is shown in FIG. Figure 7 . Grain size 700~1500nm.

[0085] It can be seen from the size of the molecular sieve grains that the ZSM-35 molecular sieve prepared by the mother liquor recycling method has a smaller grain size than the molecular sieve prepared without the circulating mother liquor.

[0086] The ZSM-35 molecular sieve prepared in Examples 1 to 5 and Comparative Example 1 was used to carry out a butene conversion experiment. 10 g of the molecular sieve was sieved to 20-40 meshes after tableting and granulation to participate in the reaction. The reaction conditions were: T = 290 ° C, P = 0.1 MPa, and air velocity 4 h -1 The calculation method of 1-butene conversion is as shown in formula (1), and the calculation method of isobutylene selectivity is as shown in formula (2):

[0087]

[0088]

[0089] Among them: A total : Total peak area; A 1-butene : 1-butene peak area; A cis-2-butene : cis-2-butene peak area; A trans-2-butene : Trans-2-butene peak area; A isobutene : Isobutylene peak area.

[0090] The molecular sieve activity test results obtained in different embodiments are shown in Table 1.

[0091] Table 1

[0092] catalyst 1-Butene conversion % Isobutylene selectivity % Example 1 47.68 75.20 Example 2 47.45 74.86 Example 3 47.31 74.20 Example 4 47.28 74.18 Example 5 47.25 74.02 Comparative Example 1 42.67 72.20

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor, characterized in that: The following steps are involved: (1) filtering the ZSM-35 molecular sieve synthesis mother liquor to remove insoluble solid impurities therein, and then distilling and concentrating it to obtain a circulating mother liquor; (2) mixing a silicon source, an aluminum source, an alkali source, a template agent, and water to obtain a raw material mixed solution, adding a circulating mother solution to obtain a molecular sieve precursor mixture; (3) transferring the molecular sieve precursor mixture of step (2) into a crystallization kettle, crystallizing at 150-190° C. for 24-96 hours, washing with water to neutrality after crystallization, and then drying and calcining to obtain Na-type ZSM-35 molecular sieve; (4) exchanging the Na-type ZSM-35 molecular sieve of step (3) with a 3-10 wt% ammonium salt aqueous solution at 40-90° C. for 1-6 h, washing with water until neutral, drying and calcining to obtain an H-type ZSM-35 molecular sieve.

2. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The filtering medium described in step (1) is one of filter paper, filter membrane and filter cloth, and the filtering accuracy of the filtering medium is 20-50 μm.

3. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The circulating mother liquor described in step (1) is a mother liquor with a template mass content of 5 to 15%.

4. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The silicon source described in step (2) is one or two of silica sol, C-type silica gel, and white carbon black; the aluminum source is one or two of sodium aluminate, aluminum sulfate, aluminum nitrate, pseudo-boehmite, and aluminum chloride; the alkali source is sodium hydroxide; and the template agent is one or two of pyrrolidine, ethylenediamine, cyclohexylamine, and pyridine.

5. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The amount of the circulating mother liquor added in step (2) is 10 to 30% of the mass of the raw material mixed liquor.

6. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The molar ratio of the silicon source, aluminum source, alkali source, template and water described in step (2) is SiO2:Al2O3:Na2O:template:H2O=30~120:1:1.0~10.0:5.0~40.0:400~2500.

7. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The drying conditions in step (3) are drying at 100-150° C. for 6-10 hours; and the roasting conditions are roasting at 450-600° C. for 4-8 hours.

8. The method for preparing high-efficiency and environmentally friendly ZSM-35 molecular sieve by recycling synthetic mother liquor according to claim 1, characterized in that: The drying conditions in step (4) are drying at 100-150° C. for 6-10 hours; and the roasting conditions are roasting at 450-600° C. for 4-8 hours.

9. An H-type ZSM-35 molecular sieve, characterized in that: Prepared according to the method according to any one of claims 1 to 8, the H-type ZSM-35 molecular sieve is a small-grain laminated H-type ZSM-35 molecular sieve.

10. The H-type ZSM-35 molecular sieve according to claim 9, characterized in that: The grain size of the H-type ZSM-35 molecular sieve is 100-450 nm.

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