A method for preparing molecular sieve membranes without solvent and regulating their orientation

Abstract

The present invention discloses a method for preparing a molecular sieve membrane with a non-solvent and regulating its orientation. The preparation of the molecular sieve membrane includes: S1, preparing a molecular sieve active component; S2, uniformly distributing the molecular sieve active component on the surface of a carrier or a carrier embryo to form a molecular sieve active layer; S3, placing the carrier or the carrier embryo in a crystallization kettle, and transferring the crystallization kettle to a drying oven after sealing to perform non-solvent crystallization synthesis, so that the molecular sieve active layer grows into a molecular sieve layer; S4, placing the carrier or the carrier embryo on which the molecular sieve layer is grown in a muffle furnace for calcination to form a molecular sieve membrane. The present invention discloses a method for preparing a molecular sieve membrane with a non-solvent and regulating its orientation. The prepared molecular sieve membrane has a dense membrane layer and good orientation, and improves the permeation flux and permeation selectivity of the molecular sieve membrane; during the preparation process, no large amount of synthetic liquid is required, which not only simplifies the preparation process of the molecular sieve membrane and reduces energy consumption, but also reduces the amount of chemical reagents used and the emission of pollutants, thereby achieving energy-saving and environmental protection effects.

Description

Technical Field

[0001] The invention relates to the technical field of membrane separation, and in particular to a method for preparing a molecular sieve membrane with a non-solvent and regulating its orientation. Background Art

[0002] Membrane separation technology has become one of the most commonly used separation technologies to solve major challenges in the fields of water resources, energy, and the environment. Membrane materials are the core of membrane separation technology and have been widely used in microfiltration, nanofiltration, ultrafiltration, and other fields. However, the preparation of membrane materials with molecular-level difference separation performance is still a recognized problem. Molecular sieve membranes have become ideal membrane materials for separating small molecule mixtures because of their uniform, molecular-level pores. After decades of exploration and research, the quality of molecular sieve membranes has been greatly improved. However, the membrane defects in molecular sieve membranes provide non-selective channels for the transmission of substances, reducing the inherent separation performance of molecular sieve membranes. Studies have shown that the crystal orientation distribution of molecular sieve membranes can eliminate membrane defects and shorten the diffusion path of guest molecules in the membrane, thereby improving the permeation flux and permeation selectivity of molecular sieve membranes.

[0003] In order to improve the orientation of molecular sieve crystal growth, the carrier needs to be modified, coated with seed crystals and then immersed in an alkaline synthesis solution for hydrothermal high-temperature crystallization synthesis. The assembly of a continuous, uniform, oriented seed crystal layer on the carrier surface is the key to preparing an oriented molecular sieve membrane. However, the porosity and roughness of the carrier lead to uneven and disordered distribution of molecular sieve structural microelements (such as secondary structural units, tiny particles, etc.) on the carrier surface during the preparation of the molecular sieve membrane. There are differences in the growth rate and growth orientation of molecular sieve crystals on the carrier surface, which ultimately leads to poor film orientation and defects. Therefore, it is urgently needed to adopt a new preparation process that is simple and environmentally friendly to prepare oriented molecular sieve membranes to improve the separation selectivity and economic performance of molecular sieve membranes. Summary of the invention

[0004] To solve the above problems, the present invention provides a method for preparing a molecular sieve membrane in a non-solvent manner and regulating its orientation. First, a molecular sieve active component is prepared, and then the molecular sieve active component is evenly distributed on the surface of a carrier (or a carrier embryo) to form a molecular sieve active layer. Subsequently, the molecular sieve active layer is allowed to grow into a molecular sieve membrane under a non-solvent state. By regulating the growth space of the molecular sieve active layer so that it grows in a confined space layer, an oriented molecular sieve membrane can be prepared.

[0005] To achieve the above object, the present invention provides a method for preparing a molecular sieve membrane using a non-solvent, comprising the following steps:

[0006] S1, preparing molecular sieve active components;

[0007] S2, evenly distributing the molecular sieve active components prepared in step S1 on the surface of the carrier or carrier embryo to form a molecular sieve active layer;

[0008] S3, placing the carrier or carrier embryo with the molecular sieve active layer formed on the surface in step S2 in a crystallization kettle, and transferring the crystallization kettle to a drying oven after sealing for non-solvent crystallization synthesis, so that the molecular sieve active layer grows into a molecular sieve layer;

[0009] S4. Placing the carrier or carrier embryo body on which the molecular sieve layer is grown in a muffle furnace and calcining the carrier to form a molecular sieve membrane.

[0010] Preferably, in step S1, the preparation method of the molecular sieve active component is: fully mixing the aluminum source, silicon source, phosphorus source, alkali source, activator and / or other materials; other materials include templates, binders, fluxes, and dispersants.

[0011] Preferably, the aluminum source includes one or more of aluminum isopropoxide, sodium aluminate, aluminum chloride, aluminum sulfate, aluminum nitrate, pseudo-boehmite, aluminum sol, boehmite, aluminum hydroxide, and aluminum oxide;

[0012] The silicon source includes one or more of sodium silicate, silica sol, ethyl orthosilicate fumed silica, and silicon dioxide;

[0013] The alkali source includes one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, and organic amine;

[0014] The phosphorus source includes one or more of phosphoric acid, phosphorus trioxide, phosphorus trichloride, phosphorus pentasulfide, sodium tripolyphosphate, calcium phosphate, and organic phosphide;

[0015] The activator includes one or more of ammonia water, dimethylamine, trimethylamine, diethylamine, triethylamine, ammonium chloride, sodium chloride, ammonium iodide, ammonium fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluorosilicate, ammonium fluoroaluminate, aluminum fluorosilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, lithium bicarbonate, sodium bicarbonate, lithium phosphate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0016] Preferably, the template agent includes one or more of tetrapropylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium chloride, tetraethylammonium hydroxide, tetraethylenepentamine, N,N,N-trimethyl-1-adamantylammonium hydroxide, cyclohexylethyldimethylammonium hydroxide, 1-ethyl-3-methylimidazole acetate, N-cyclohexylmaleimide, hexamethylammonium bromide, tetraethylammonium bromide, tetraethylammonium chloride, tetramethylammonium hydroxide, tetramethylammonium bromide, and tetramethylammonium chloride;

[0017] The dispersant includes one or more of water, methanol, ethanol, propanol, ethylene glycol, propylene glycol, butanediol, acetone, tetrahydrofuran, dimethyl ether, N-methylpyrrolidone, and N,N-dimethylformamide;

[0018] The flux includes one or more of silicon dioxide, aluminum oxide, talc, titanium dioxide, and clay;

[0019] The binder includes one or more of methyl cellulose, carboxymethyl cellulose, starch, chitosan, urea, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyvinyl butyral, polystyrene, polyethylene glycol, polyethylene, polyvinyl alcohol, polyoxyethylene, and polyoxypropylene.

[0020] Preferably, in step S1, the molecular sieve active component is obtained by activating clay and then supplementing it with an aluminum source, a silicon source, a phosphorus source, an alkali source, an activator and / or other materials;

[0021] The clay includes one or more of kaolin, montmorillonite, attapulgite, illite, diatomaceous earth, sepiolite, hydromica, glauconite and chlorite.

[0022] Preferably, the method for forming the molecular sieve active layer in step S2 comprises:

[0023] The molecular sieve active components are made into carriers or carrier embryos in the form of sheets, single tubes, multiple channels or hollow fibers by extrusion, pressing, coating, scraping or self-assembly;

[0024] Or the molecular sieve active components are evenly distributed on the carrier surface by layer-by-layer dipping, wiping, spraying, spin coating, self-assembly, vacuum filtration and a combination of these methods.

[0025] Preferably, in step S3, a container A and a container B are provided in the crystallization reactor, the container A contains an alkaline aqueous solution, and the container B contains an organic solvent;

[0026] The alkaline aqueous solution is an ammonia solution or an organic amine solution with a mass content of 0%-100%;

[0027] The organic solvent includes one or more organic solvents that are immiscible with water, such as benzene, carbon tetrachloride, petroleum ether, toluene, n-butanol, xylene, cyclohexane, ether, etc.;

[0028] The carrier or carrier embryo in the crystallization kettle is not in contact with the liquid in the A container and the B container.

[0029] Preferably, in step S3, the crystallization temperature during the non-solvent crystallization synthesis is 50° C.-300° C., and the crystallization time is 3 h-24 h.

[0030] Preferably, in step S4, the calcination temperature is 200°C-1500°C, the calcination time is 0.5h-48h, the heating and cooling rate is 0.1°C / min-10°C / min, and the temperature between 150°C-500°C can be maintained for 0.5h-6h during the heating process.

[0031] A method for orientation control of a molecular sieve membrane, wherein the molecular sieve membrane is prepared according to the above-mentioned method for preparing a molecular sieve membrane using a non-solvent, wherein the orientation control is to control the formation of an oil film on the surface of a water film on the surface of an active layer of the molecular sieve, wherein the oil film has a limiting effect on the growth of the molecular sieve so that the molecular sieve can only grow along the direction of the water film, and as time goes by, adjacent molecular sieves contact each other and eventually form a dense oriented molecular sieve membrane;

[0032] The water film is formed by regulating the water in the active component of the molecular sieve or the alkaline aqueous solution in container A, and the oil film is formed by regulating the organic solvent in container B.

[0033] The present invention utilizes non-solvent conversion to prepare a molecular sieve membrane. During the crystallization process, a "water film" is formed on the surface of the molecular sieve active layer. The specific atmosphere of the "water film" converts the active components in the molecular sieve active layer into molecular sieve crystal nuclei, which grow to form molecular sieve particles. Due to the spatial restriction of the molecular sieve active component layer, the molecular sieve can only grow in the water film outside the molecular sieve active component layer. As the crystallization time increases, the molecular sieve particles gradually grow, contact and cross-link with adjacent molecular sieves to form twins, and prepare a dense molecular sieve layer.

[0034] During the crystallization process, the organic solvent that is immiscible with water in the container of the crystallization kettle vaporizes and forms an "oil film" on the surface of the "water film". The "water film" is confined between the molecular sieve active layer and the "oil film", forming a two-dimensional confined space layer. Due to the effect of the two-dimensional confined space, the molecular sieve can only grow along the direction of the "water film". As time goes by, adjacent molecular sieves contact each other and eventually form a dense oriented molecular sieve film.

[0035] The invention discloses a method for preparing a molecular sieve membrane with a non-solvent and regulating its orientation. The prepared molecular sieve membrane has a dense film layer and good orientation, and the permeation flux and permeation selectivity of the molecular sieve membrane are improved. In addition, during the preparation of the molecular sieve membrane, a large amount of synthetic liquid is not required; not only the preparation process of the molecular sieve membrane is simplified, energy consumption is reduced, but also the amount of chemical reagents used is reduced, the emission of pollutants is reduced, and the effect of energy saving and environmental protection is achieved.

[0036] The molecular sieve membrane provided by the present invention is mainly used for separation of homogeneous systems, such as separation of mixed gases, separation of alcohol-water mixtures, separation of isomers of organic matter, etc. Preferably, it is used for separation of methanol and methyl tert-butyl ether, or for separation of water and ethanol; separation of p-xylene and other xylenes, separation of propanol and water, separation of oil and water, and battery separator, with ultra-high permeation selectivity.

[0037] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a SEM image of the ZSM-5 molecular sieve membrane obtained in Example 1;

[0039] Figure 2 This is a SEM image of the oriented ZSM-5 molecular sieve membrane obtained in Example 2;

[0040] Figure 3 This is a SEM image of the LTA molecular sieve membrane obtained in Example 5;

[0041] Figure 4 This is a SEM image of the FAU molecular sieve membrane obtained in Example 6;

[0042] Figure 5 This is the SEM image of the oriented FAU molecular sieve membrane obtained in Example 7. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0044] Embodiment 1

[0045] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0046] S1, 2.0g SiO 2 , 0.5 g sodium aluminate, 0.5 g TPABr and 0.6 g NH 4 F was mixed and ground for 5 minutes to obtain the molecular sieve active component.

[0047] S2. Apply the molecular sieve active components to the surface of the carrier.

[0048] S3. Place the carrier loaded with the molecular sieve active layer above the crystallization kettle without contact with the liquid. Container A in the crystallization kettle contains 2 mL of ammonia water, and container B does not contain any liquid. Seal the crystallization kettle and crystallize at 200°C for 12 hours. After crystallization, take out the carrier and dry it at 80°C for 24 hours.

[0049] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.3°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and calcine it for 6 hours to obtain a ZSM-5 molecular sieve membrane.

[0050] The permeability of the prepared ZSM-5 molecular sieve membrane was tested. The permeability flux of the ZSM-5 molecular sieve membrane was 7.2 kg·m-2 ·h -1 , the permeation selectivity of paraxylene relative to other xylenes is greater than 2000.

[0051] like Figure 1 The figure shows the SEM image of the ZSM-5 molecular sieve membrane obtained in Example 1. As can be seen from the figure, a dense, flat, and defect-free ZSM-5 molecular sieve membrane is formed on the surface of the carrier.

[0052] Embodiment 2

[0053] A method for preparing an oriented molecular sieve membrane using a non-solvent comprises the following steps:

[0054] S1, 0.3g SiO 2 , 1.5gNa 2 SiO 3 , 0.2 g TPABr and 0.4 g NH 4 Cl was mixed and ground for 10 min to obtain the molecular sieve active component.

[0055] S2. Disperse 1 g of molecular sieve active component in 100 mL of anhydrous ethanol, stir at high speed to obtain a suspension of molecular sieve active component, and then immerse the carrier in the suspension for 1 min. Subsequently, slowly pull out the carrier and dry it at 60°C for 3 h to obtain a carrier loaded with a molecular sieve active layer.

[0056] S3. Place the carrier loaded with the molecular sieve active layer above the crystallization kettle without contact with the liquid. Put 2 mL of ammonia water in container A and 2 mL of toluene in container B in the crystallization kettle. Seal the crystallization kettle and crystallize at 240°C for 3 hours. After the crystallization is completed, take out the carrier and dry it at 100°C for 24 hours.

[0057] S4. Place the treated carrier in a muffle furnace in an air atmosphere at a heating rate of 0.5°C / min, keep it at 250°C for 2 hours, then heat it to 600°C and calcine it for 10 hours to obtain an oriented ZSM-5 molecular sieve membrane.

[0058] The permeability performance of the prepared oriented ZSM-5 molecular sieve membrane was tested. The permeability flux of the ZSM-5 molecular sieve membrane was 10.3 kg·m -2 ·h -1 , the permeation selectivity of paraxylene relative to other xylenes is greater than 2000.

[0059] like Figure 2 The figure shows the SEM image of the ZSM-5 molecular sieve membrane obtained in Example 2. As can be seen from the figure, a dense, flat, defect-free, oriented-grown ZSM-5 molecular sieve membrane is generated on the surface of the carrier.

[0060] Embodiment 3

[0061] A method for preparing an oriented molecular sieve membrane using a non-solvent comprises the following steps:

[0062] S1, 1.2g SiO 2 , 0.18gNaAlO 2 The mixture was mixed with 0.05 g NaOH and ground for 15 min to obtain the molecular sieve active component.

[0063] S2. Disperse 1 g of molecular sieve active component into 50 mL of N-methylpyrrolidone and stir at high speed to obtain a suspension of molecular sieve active component. Then spray the suspension onto the surface of the carrier and dry it at 150° C. for 6 h to obtain a carrier loaded with a molecular sieve active layer.

[0064] S3. Place the carrier loaded with the molecular sieve active layer above the crystallization kettle without contact with the liquid. Put 2 mL of water in container A and 2 mL of carbon tetrachloride in container B in the crystallization kettle. Seal the crystallization kettle and crystallize at 210°C for 8 h. After the crystallization is completed, take out the carrier and dry it at 100°C for 24 h.

[0065] S4. Place the treated carrier in a muffle furnace in an air atmosphere at a heating rate of 5°C / min, keep the temperature at 150°C for 2 hours, then heat to 700°C and calcine for 3 hours to obtain an oriented MOR molecular sieve membrane.

[0066] Embodiment 4

[0067] A method for preparing an oriented molecular sieve membrane using a non-solvent comprises the following steps:

[0068] S1, 1.3g SiO 2 , 1.2 g Na 2 SiO 3 , 0.1 g boehmite and 0.9 g TEAOH were mixed and ball-milled for 1 h to obtain the molecular sieve active component.

[0069] S2. Apply the molecular sieve active components to the surface of the carrier.

[0070] S3. Place the carrier loaded with the molecular sieve active layer above the crystallization kettle without contact with the liquid. Put 5 mL of ammonia water in container A and 1 mL of benzene in container B in the crystallization kettle. Seal the crystallization kettle and crystallize at 200°C for 24 hours. After the crystallization is completed, take out the carrier and dry it at 100°C for 24 hours.

[0071] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 1°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and bake it for 24 hours to obtain an oriented Beta molecular sieve membrane.

[0072] The permeability of the prepared oriented beta molecular sieve membrane was tested, and the permeability flux of the beta molecular sieve membrane was 8.1 kg·m-2 ·h -1 , the permeation selectivity of paraxylene relative to other xylenes is greater than 1000.

[0073] Embodiment 5

[0074] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0075] S1, 4.1g NaAlO 2 , 7g SiO 2 , and 4 g NaOH and then ground for 5 minutes to obtain the molecular sieve active component.

[0076] S2. Apply the molecular sieve active components to the surface of the carrier.

[0077] S3. Place the carrier loaded with the molecular sieve active layer above the crystallization kettle without contact with the liquid. 3 mL of water is placed in container A in the crystallization kettle, and container B does not contain any liquid. Seal the crystallization kettle and crystallize at 90°C for 72 hours. After crystallization, take out the carrier and dry it at 100°C for 24 hours.

[0078] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.5°C / min. Keep it at 150°C for 2 hours, then heat it to 400°C and calcine it for 8 hours to obtain an LTA molecular sieve membrane.

[0079] The permeability performance of the prepared LTA molecular sieve membrane was tested, and the permeability flux of the LTA molecular sieve membrane was 21.1 kg·m -2 ·h -1 , the alcohol-water permeability selectivity is greater than 10000.

[0080] like Figure 3 The figure shows the SEM image of the LTA molecular sieve membrane obtained in Example 5. As can be seen from the figure, a dense, flat, and defect-free LTA molecular sieve membrane is formed on the surface of the carrier.

[0081] Embodiment 6

[0082] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0083] S1, 1.1g NaAlO 2 , 23.5g Na 2 SiO 3 9H 2 O and 17.9 g NaOH were mixed and ground for 10 min to obtain the molecular sieve active component.

[0084] S2. Apply the molecular sieve active components to the surface of the carrier.

[0085] S3. Place the carrier loaded with the molecular sieve active layer on top of the crystallization kettle. There is no liquid in the A container and there is no liquid in the B container. Seal the crystallization kettle and crystallize at 60°C for 120h. After the crystallization is completed, take out the carrier, wash it with deionized water until it is neutral, and dry it at 60°C for 24h.

[0086] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 1°C / min. Keep it at 200°C for 2 hours, then heat it to 600°C and calcine it for 20 hours to obtain a FAU molecular sieve membrane.

[0087] The permeability of the prepared FAU molecular sieve membrane was tested. The permeability flux of the FAU molecular sieve membrane was 9.5 kg·m -2 ·h -1 , the separation efficiency of methanol and methyl tert-butyl ether is higher than 5000.

[0088] like Figure 4 The figure shows the SEM image of the FAU molecular sieve membrane obtained in Example 6. As can be seen from the figure, a dense, flat, and defect-free FAU molecular sieve membrane is formed on the surface of the carrier.

[0089] Embodiment 7

[0090] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0091] S1, 1.6g NaAlO 2 、16.8g Na 2 SiO 3 9H 2 O and 14.5 g NaOH were mixed and ground for 10 min to obtain the molecular sieve active component.

[0092] S2. Apply the molecular sieve active components to the surface of the carrier.

[0093] S3. Place the carrier loaded with the molecular sieve active layer on top of the crystallization kettle. There is no liquid in the A container in the crystallization kettle. The B container contains 2 mL of cyclohexane. Seal the crystallization kettle and crystallize at 60°C for 48 hours. After the crystallization is completed, take out the carrier, wash it with deionized water until it is neutral, and dry it at 60°C for 24 hours.

[0094] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.3°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and bake it for 6 hours to obtain a FAU molecular sieve membrane.

[0095] The permeability performance of the prepared FAU molecular sieve membrane was tested, and the permeability flux of the FAU molecular sieve membrane was 16.7 kg·m -2 ·h -1 , the separation efficiency of methanol and methyl tert-butyl ether is higher than 5000.

[0096] like Figure 5 The figure shows the SEM image of the FAU molecular sieve membrane obtained in Example 7. As can be seen from the figure, a dense, flat, defect-free, oriented FAU molecular sieve membrane is generated on the surface of the carrier.

[0097] Embodiment 8

[0098] A method for preparing an oriented molecular sieve membrane using a non-solvent comprises the following steps:

[0099] S1. Mix 3 g of pretreated attapulgite, 0.3 g of methyl cellulose and 0.5 g of potassium hydroxide and grind for 30 min.

[0100] S2. Use a tablet press to press it into a sheet-like carrier embryo, and the molecular sieve active components are evenly distributed on the surface of the carrier embryo.

[0101] S3. Place the carrier embryo on top of the crystallization kettle. Container A in the crystallization kettle contains 5 mL of 20% tetramethylammonium hydroxide by mass, and container B contains 2 mL of ether. Seal the crystallization kettle and crystallize at 120°C for 24 hours. After crystallization, take out the carrier and dry it at 60°C for 24 hours.

[0102] S4. After the crystallization kettle is cooled, the sheet carrier precursor is taken out and placed in a muffle furnace and calcined at 1000° C. for 6 h to obtain a FAU molecular sieve membrane. The heating and cooling rate is 1° C. / min, and the temperature is kept at 250° C. for 1 h to prepare an oriented FAU molecular sieve membrane.

[0103] The permeability performance of the prepared oriented FAU molecular sieve membrane was tested, and the permeability flux of the FAU molecular sieve membrane was 11.1 kg·m -2 ·h -1 , the separation efficiency of methanol and methyl tert-butyl ether is higher than 3000.

[0104] Embodiment 9

[0105] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0106] S1, 0.1g NaAlO 2 , 20g Na 2 SiO 3 9H 2 O and 0.4 g NaOH were dissolved in 40 g water and stirred for 2 h to obtain the molecular sieve active component.

[0107] S2. Dip-coat the molecular sieve active components onto the carrier surface.

[0108] S3. Place the carrier loaded with the molecular sieve active layer on top of the crystallization kettle. There is no liquid in the A container and there is no liquid in the B container. Seal the crystallization kettle and crystallize at 160°C for 144 hours. After the crystallization is completed, take out the carrier, wash it with deionized water until it is neutral, and dry it at 60°C for 24 hours.

[0109] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.3°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and calcine it for 6 hours to obtain a CHA molecular sieve membrane.

[0110] Embodiment 10

[0111] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0112] S1, 0.3g NaAlO 2 、6.3gNa 2 SiO 3 9H 2 O, 0.5 g NH 4 F and 0.5 g NaOH were dissolved in 30 g water and stirred for 6 h to obtain the molecular sieve active component.

[0113] S2. Dip-coat the molecular sieve active components onto the carrier surface.

[0114] S3. Place the carrier loaded with the molecular sieve active layer on top of the crystallization kettle. There is no liquid in the A container and there is no liquid in the B container. Seal the crystallization kettle and crystallize at 150°C for 120h. After the crystallization is completed, take out the carrier, wash it with deionized water until it is neutral, and dry it at 60°C for 12h.

[0115] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.3°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and calcine it for 6 hours to obtain a MOR molecular sieve membrane.

[0116] Embodiment 11

[0117] A method for preparing a non-oriented molecular sieve membrane using a non-solvent, comprising the following steps:

[0118] S1, 0.3g NaAlO 2 , 3gNa 2 SiO 3 9H 2 O, 0.5 g H 3 PO 4 , 0.3 g TEAOH, 0.2 g DPA and 0.5 g NaOH were dissolved in 50 g water and stirred for 12 h to obtain the molecular sieve active component.

[0119] S2. Dip-coat the molecular sieve active components onto the carrier surface.

[0120] S3. Place the carrier loaded with the molecular sieve active layer on top of the crystallization kettle. There is no liquid in the A container and there is no liquid in the B container. Seal the crystallization kettle and crystallize at 100°C for 80 hours. After the crystallization is completed, take out the carrier, wash it with deionized water until it is neutral, and dry it at 60°C for 12 hours.

[0121] S4. Place the treated carrier in a muffle furnace with an air atmosphere and heat it up and down at a rate of 0.3°C / min. Keep it at 200°C for 2 hours, then heat it to 500°C and calcine it for 6 hours to obtain a SAPO molecular sieve membrane.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for orientation control of a molecular sieve membrane, characterized in that: The method for preparing a molecular sieve membrane using a non-solvent comprises the following steps: S1, preparing molecular sieve active components; S2, evenly distributing the molecular sieve active components prepared in step S1 on the surface of the carrier to form a molecular sieve active layer; S3, placing the carrier with the molecular sieve active layer formed on the surface in step S2 in a crystallization kettle, and transferring the crystallization kettle to a drying oven after sealing for non-solvent crystallization synthesis, so that the molecular sieve active layer grows into a molecular sieve layer; S4, placing the carrier for growing the molecular sieve layer in a muffle furnace and calcining it to form a molecular sieve membrane; The method for forming the molecular sieve active layer in step S2 includes: The molecular sieve active components are uniformly distributed on the carrier surface by layer-by-layer dip coating, wiping coating, spray coating, spin coating, self-assembly, vacuum filtration or a combination of these methods; In step S3, a container A and a container B are set in the crystallization kettle, the container A contains water or alkaline aqueous solution; the container B contains an organic solvent; The alkaline aqueous solution is aqueous ammonia or an organic amine solution; The organic solvent includes one or more of benzene, carbon tetrachloride, petroleum ether, toluene, n-butanol, xylene, cyclohexane, and ether; The carrier in the crystallization kettle does not contact the liquid in the A container and the B container; Orientation regulation is to control the formation of oil film on the surface of the water film on the surface of the molecular sieve active layer. The oil film has a limiting effect on the growth of the molecular sieve so that the molecular sieve can only grow along the direction of the water film. As time goes by, the adjacent molecular sieves contact each other and eventually form a dense oriented molecular sieve film. The water film is formed by regulating the water in the active component of the molecular sieve or the water or alkaline aqueous solution in container A, and the oil film is formed by regulating the organic solvent in container B.

2. A method for orientation control of a molecular sieve membrane according to claim 1, characterized in that: In step S1, the preparation method of the molecular sieve active component is: fully mix the aluminum source, silicon source, phosphorus source, alkali source, activator and / or other materials; other materials include templates, binders, flux or dispersants.

3. A method for orientation control of a molecular sieve membrane according to claim 2, characterized in that: The aluminum source includes one or more of aluminum isopropoxide, sodium aluminate, aluminum chloride, aluminum sulfate, aluminum nitrate, pseudo-boehmite, aluminum sol, boehmite, aluminum hydroxide, and aluminum oxide; The silicon source includes one or more of sodium silicate, silica sol, ethyl orthosilicate, fumed silica, and silicon dioxide; The alkali source includes one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, and organic amine; The phosphorus source includes one or more of phosphoric acid, phosphorus trioxide, phosphorus trichloride, phosphorus pentasulfide, sodium tripolyphosphate, calcium phosphate, and organic phosphide; The activator includes one or more of ammonia water, dimethylamine, trimethylamine, diethylamine, triethylamine, ammonium chloride, sodium chloride, ammonium iodide, ammonium fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluorosilicate, ammonium fluoroaluminate, aluminum fluorosilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, lithium bicarbonate, sodium bicarbonate, lithium phosphate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate, and sodium dihydrogen phosphate.

4. A method for orientation control of a molecular sieve membrane according to claim 2, characterized in that: The template agent includes one or more of tetrapropylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium chloride, tetraethylammonium hydroxide, tetraethylenepentamine, N,N,N-trimethyl-1-adamantylammonium hydroxide, cyclohexylethyldimethylammonium hydroxide, 1-ethyl-3-methylimidazole acetate, N-cyclohexylmaleimide, hexamethylammonium bromide, tetraethylammonium bromide, tetraethylammonium chloride, tetramethylammonium hydroxide, tetramethylammonium bromide, and tetramethylammonium chloride; The dispersant includes one or more of water, methanol, ethanol, propanol, ethylene glycol, propylene glycol, butanediol, acetone, tetrahydrofuran, dimethyl ether, N-methylpyrrolidone, and N,N-dimethylformamide; The flux includes one or more of silicon dioxide, aluminum oxide, talc, titanium dioxide, and clay; The binder includes one or more of methyl cellulose, carboxymethyl cellulose, starch, chitosan, urea, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyvinyl butyral, polyethylene glycol, polyethylene, polyvinyl alcohol, polyoxyethylene, and polyoxypropylene.

5. A method for orientation control of a molecular sieve membrane according to claim 1 or 2, characterized in that: In step S1, the molecular sieve active component is prepared by activating clay and then adding aluminum source, silicon source, phosphorus source, alkali source, activator and / or other materials; The clay includes one or more of kaolin, montmorillonite, attapulgite, illite, diatomaceous earth, sepiolite, hydromica, glauconite and chlorite.

6. The method for orientation control of a molecular sieve membrane according to claim 1, characterized in that: In step S3, the crystallization temperature during the non-solvent crystallization synthesis is 50° C.-300° C., and the crystallization time is 3 h-24 h.

7. The method for orientation control of a molecular sieve membrane according to claim 1, characterized in that: In step S4, the calcination temperature is 400°C-1500°C, the calcination time is 0.5h-48h, the heating and cooling rate is 0.1°C / min-10°C / min, and the temperature between 150°C-500°C is maintained for 0.5h-6h during the heating process.

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