KR20230062049A - SAPO-34 zeolite-coated composite membrane manufacturing method and SAPO-34 zeolite coated composite membrane manufactured through the same for gas separation - Google Patents

Abstract

Disclosed is a manufacturing method for silicoaluminophosphate-34 (SAPO-34) composite membrane, which comprises the steps of: preparing a SAPO-34 seed solution including at least one aluminum supply source, at least one phosphorus supply source, at least one silicon supply source, at least one organic mold body, and water; preparing a SAPO-34 growth solution including at least one aluminum supply source, at least one phosphorus supply source, at least one silicon supply source, at least one organic mold body, and water; immersing a supporter in the SAPO-34 seed solution; calcining the supporter; and hydrothermal-synthesizing the supporter by immersing the same in the SAPO-34 growth solution. Accordingly, the silicoaluminophosphate-34 (SAPO-34) composite membrane of the present invention has excellent separation characteristics for separating nitrogen and methane, hydrogen and carbon dioxide, hydrogen and methane, and hydrogen and nitrogen.

Description

SAPO-34 zeolite-coated composite membrane manufacturing method and SAPO-34 zeolite coated composite membrane manufactured through the same for gas separation}

A method for manufacturing a gas separation composite membrane coated with a thin film of SAPO-34 zeolite and a SAPO-34 zeolite gas separation composite membrane manufactured thereby.

Natural gas, whose main component is methane, accounts for about 23% of global energy consumption (J. Membr. Sci 520 (2016) 240), and the International Energy Agency (IEA) predicts that it will increase by 44% by 2035. . Methane (CH ₄ ) in methane-containing natural gas, shale gas, landfill, etc. exists together with impurities such as carbon dioxide (CO ₂ ), nitrogen (N ₂ ), and hydrogen (H ₂ ), so separation and purification are essential. In particular, in the case of the United States, about 17% of natural gas formations are not utilized due to high nitrogen concentration. In research on landfill gas, biomass, and organic waste, high-concentration methane contains carbon dioxide and nitrogen as impurities. Looking at the technical data of Daewoo E&C/Gas Corporation, in some cases, more than 20% of nitrogen contains 10-50% of nitrogen, and in the case of methane containing nitrogen, natural gas, sale gas, coal gas field, landfill, etc. Assuming that the substitution effect is KRW 600,000/ton, it is estimated to be equivalent to KRW 144 trillion worldwide.

In order to recover high-purity methane, the existing distillation technology has similar liquefaction temperatures of nitrogen and methane, so energy consumption is high and a large plant is required. In addition, the removal of carbon dioxide can be sufficiently removed with existing absorption, adsorption, and separation membrane materials and technologies, but nitrogen and methane have similar kinetic diameters of 0.365 nm for nitrogen and 0.4 nm for methane, so adsorption and membrane There is no separation technology commercialized in separation, etc., so it is not mined or burned as it is.

<Reference table>

The current gas separation membrane technology removes such nitrogen and recovers high-purity methane, refines it while consuming less energy than deep cold distillation, and can replace natural gas at least 1/4 cheaper than deep cold distillation, so it is very economical. (Lokhandwala et al. (2010) J. of Membrane Sci., 346, 270-279). The Wessling group in Germany has proposed CH ₄ /N ₂ 6.7 ~ 8.0 or N ₂ /CH ₄ 3.5 ~ 4.0 or more as membrane selectivity for methane recovery (J. Membr. Sci. 2016, 498, 291-301). .

In particular, it has the advantage of being easily applicable to small and medium-sized scattered natural gas or landfill generating areas, so when the membrane separation process is introduced, small and medium-sized intensive plants are possible, and accordingly, N ₂ /CH ₄ or CH ₄ /N ₂ Separation membranes for N ₂ removal with high selectivity and permeability are required, and the development and process of membrane separation materials are important areas of research.

Looking at an example of a separation membrane study using a nitrogen/methane polymer material in the past. In US Patent No. 9403120, a gas separation membrane was prepared using a perfluorinated monomer (N ₂ /CH ₄ selectivity 5.3, N ₂ permeance 28 GPU), and a siloxane-based composite membrane was applied by MTR in the United States under the commercial name NitroSep™. _{A 4} /N ₂ separation membrane was manufactured and a membrane separation process was developed, but the selectivity of the separation membrane is low to about 3 to 4, which is insufficient for commercialization. In the case of a carbon molecular sieve membrane to which a carbonization process of polyimide based on matrimid 5218 was applied, the selectivity of nitrogen/methane was higher than 8, but the permeability was still as low as several GPUs, making commercialization difficult (ada. Materials, 2017, 170-631). . US Patent No. 6630011 designed a two-step process using a CH ₄ selective membrane and an N ₂ selective membrane, but there are still many difficulties in commercialization due to low N ₂ /CH ₄ or CH ₄ /N ₂ selectivity and permeability. .

Accordingly, in the development of high permeability and high selectivity N ₂ /CH ₄ or CH ₄ /N ₂ separation membranes, silicon aluminium is an important inorganic membrane material that can overcome the limitations (3 to 4) of low nitrogen/methane selectivity of existing polymer membranes. Norphosphate (SAPO) has attracted attention as a material ^with a three-dimensional microporous crystal framework structure of PO ₂₊ , AlO ₂ ^- and SiO ₂ tetrahedral units. Its essential empirical chemical composition based on the anhydrous state in as-synthesized form can be expressed as:

mR:(Si _x Al _y P _z ) O ₂

In the above formula, R represents at least one organic structure directing agent present in the intracrystalline pore system, and m is the number of R present per mole of (Si _x Al _y P _z ) O ₂ represent moles, and x, y and z represent the mole fractions of silicon, aluminum and phosphorus present in the oxide moiety, respectively.

SAPO-n, a silicoaluminophosphate-based molecular sieve, uses an organic amine as a template and alumina hydrate, phosphoric acid, and silica sol as an aluminum source, phosphorus source, and silicon source. It is obtained by removing the template agent (organic amine) through roasting after forming the /silicoaluminophosphate complex. Here, SAPO-34, a silicoaluminophosphate molecular chain with a CHA topology structure, has an appropriate channel structure, appropriate protonic acid properties, relatively large specific surface area, desirable adsorption performance, and desirable thermal and hydrothermal stability, etc. It shows excellent catalytic activity and selectivity in the olefin production (MTO) reaction by

SAPO-34 is a chabazite-type (CHA) molecular sieve, which has an octagonal ring elliptical cage formed by stacking double hexagonal rings in an ABC manner and a three-dimensional cross-channel structure, with a pore diameter of 038 × 038 nm and a fine pore size belongs to itself Its spatial symmetry group is R3m, which belongs to the trigonal crystal system. SAPO-34 is composed of four elements of Si, Al, P, and O, and its composition varies within a certain range, and is generally n(Si)<n(P)<n(Al). This SAPO-34 has a pore diameter of 0.38 nm, so that it can selectively transmit nitrogen (molecular size: 0.365 nm) and function as a separator to prevent methane (molecular size: 0.4 nm) from permeating. However, since nitrogen also has a molecular size similar to the pore size of SAPO-34, there is a problem in that it receives high diffusion resistance when permeating through the separator.

In particular, in the manufacture of SAPO-34 separator, continuous thin film formation without defects is important for commercialization, but since it is synthesized at a high temperature of 200 ℃ or more during the manufacturing process, it is difficult to secure the uniformity of the coating layer in the process of crystal growth. The coating thickness of the separation membrane is 5 μm or more, and the selectivity of nitrogen / methane can be obtained up to 8.6. However, if the nitrogen permeability is low to tens of GPUs or less and the nitrogen permeability is increased by lowering the coating thickness to 3 μm or less, defects occur and commercialization is still a problem. There was (J. of Membrane Sci., 2017, 17~123).

An object of one aspect of the present invention is to form a defect-free coating layer of less than 3 μm on a porous ceramic layer for a SAPO-34-based molecular sieve material having excellent nitrogen / methane selectivity and excellent nitrogen permeability at the same time. It is an object of the present invention to provide a method for preparing a composite membrane that is as thin as 0.1 μm and has high nitrogen permeability and excellent nitrogen/methane selectivity.

Another object of the present invention is to provide a method for preparing a composite membrane based on a SAPO-34 molecular sieve having excellent hydrogen/carbon dioxide, hydrogen/methane, and hydrogen/nitrogen selectivity and excellent permeability.

In order to achieve the above object, in one aspect of the present invention

preparing a SAPO-34 seed solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;

preparing a SAPO-34 growth solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;

immersing the support in the SAPO-34 seed solution;

calcining the support; and

A method for preparing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of hydrothermal synthesis by immersing the support in the SAPO-34 growth solution is provided.

Also, in another aspect of the present invention

It is produced by the above manufacturing method,

A support and a SAPO-34 zeolite layer formed on the surface of the support,

The thickness of the SAPO-34 zeolite layer is provided with a silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that 0.1 ㎛ to 3 ㎛.

Furthermore, in another aspect of the present invention

A support and a SAPO-34 zeolite layer formed on the surface of the support,

The thickness of the SAPO-34 zeolite layer is 0.1 μm to 3 μm,

Silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that it is applied for separation between gases selected from the group consisting of nitrogen / methane separation, hydrogen / carbon dioxide separation, hydrogen / methane separation and hydrogen / nitrogen separation Provided.

The composite membrane prepared by the manufacturing method of the SAPO-34 composite membrane provided in one aspect of the present invention maintains a nitrogen/methane selectivity of 7 or more, and has a nitrogen permeability exceeding 100 GPU, resulting in excellent gas separation performance.

1 is a photograph of seed crystals of the SAPO-34 seed solution prepared in Example 1 observed with a scanning electron microscope (SEM);
2 is a photograph of the SAPO-34 composite film prepared in Example 1 observed with a scanning electron microscope (SEM).

In one aspect of the invention

preparing a SAPO-34 seed solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;

preparing a SAPO-34 growth solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;

immersing the support in the SAPO-34 seed solution;

calcining the support; and

A method for preparing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of hydrothermal synthesis by immersing the support in the SAPO-34 growth solution is provided.

Hereinafter, a method for manufacturing a SAPO-34 composite membrane provided in one aspect of the present invention will be described in detail for each step.

The composite membrane prepared by the above method may be applied as a composite membrane for nitrogen/methane separation, a composite membrane for hydrogen/carbon dioxide separation, a composite membrane for hydrogen/methane separation, and a composite membrane for hydrogen/nitrogen separation. As a specific example, it can be applied for nitrogen / methane separation and exhibit high permeability as well as high selectivity.

First, the method for manufacturing a SAPO-34 composite film provided in one aspect of the present invention includes at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template, and water. and preparing the seed solution.

Next, the method for manufacturing a SAPO-34 composite film provided in one aspect of the present invention includes at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template, and water. 34 includes preparing the growth solution.

By preparing a SAPO-34 seed solution and a SAPO-34 growth solution through the above steps, SAPO-34 synthesis can be performed through seed coating and seed growth on a support described later.

As the aluminum source, alumina alkoxide and pseudo-Boehmite may be used.

As the phosphorus source, organic phosphates such as phosphoric acid (H ₃ PO ₄ ) and triethyl phosphate, and organic phosphoric acid compounds such as tetrabutylphosphonium bromide (TBPB) may be used.

As the silicon source, colloidal silica, fumed silica, and silica sol may be used.

The organic template is tetraethylammonium hydroxide (TEAOH), diethylamine (DEA), triethylamine (TEA), morpholine, dipropylamine (DPA), isopropylamine (IPA) and diethylamine. Ethanolamine (DEtA) and the like can be used.

The SAPO-34 seed solution preferably has the following molar composition.

1 Al ₂ O ₃ : a P ₂ O ₅ : b SiO ₂ : c Organic template : d H ₂ O

where a ranges from 1 to 3, b ranges from 0.3 to 0.9, c ranges from 2 to 8, and d ranges from 30 to 150.

Specifically, a may range from 1.2 to 2.8, may range from 1.4 to 2.6, may range from 1.6 to 2.4, may range from 1.8 to 2.2, or may range from 1.9 to 2.1.

In addition, b may range from 0.4 to 0.8, may range from 0.45 to 0.75, may range from 0.5 to 0.7, may range from 0.55 to 0.65, and may range from 0.57 to 0.63.

In addition, c may be in the range of 2.3 to 7.6, may be in the range of 2.6 to 7.2, may be in the range of 2.9 to 6.8, may be in the range of 3.2 to 6.4, may be in the range of 3.5 to 6.0, may be in the range of 3.8 to 5.6.

In addition, d may be in the range of 40 to 120, may be in the range of 50 to 100, may be in the range of 60 to 90, may be in the range of 65 to 85, may be in the range of 70 to 80, and may be in the range of 72 to 78.

Furthermore, the step of preparing the SAPO-34 seed solution,

preparing a mixture of at least one aluminum source, at least one organic mold and water;

adding at least one silicon source to the mixture;

adding at least one phosphorus source to the mixture; and

It may include; hydrothermal synthesis of the mixture.

In the step of preparing the mixture of the at least one aluminum source, the at least one organic template, and water, the preparation of the mixture is 60 minutes to 240 minutes, 90 minutes to 180 °C in the temperature range of 20 ° C to 40 ° C, 25 ° C to 35 ° C. It can be done in minutes.

In the step of adding at least one silicon source to the mixture, a stirring process for mixing may be performed after the addition, and at a temperature range of 20 ° C to 40 ° C, 25 ° C to 35 ° C, 30 minutes to 120 minutes, 45 minutes to 45 minutes It can be done for 90 minutes.

The step of adding at least one phosphorus source to the mixture may be a slow dropwise addition over 10 minutes to 60 minutes and 20 minutes to 50 minutes when phosphoric acid is applied. A stirring process for mixing may be performed, and may be performed for 12 to 60 hours and 24 to 48 hours at a temperature range of 20 ° C to 40 ° C and 25 ° C to 35 ° C.

The hydrothermal synthesis is carried out in a temperature range of 120 ° C to 180 ° C, 130 ° C to 180 ° C, 140 ° C to 180 ° C, 150 ° C to 180 ° C, 160 ° C to 180 ° C for 12 hours to 60 hours, 16 hours to 54 hours, 20 It is preferably carried out for 48 hours, 34 hours to 42 hours.

The SAPO-34 growth solution may include a first organic template and a second organic template as organic templates, and preferably has the following molar composition. The first organic template may be tetraethylammonium hydroxide, and the second organic template may be dipropylamine.

1 Al ₂ O ₃ : a P ₂ O ₅ : b SiO ₂ : c' first organic template: c'' second organic template: d H ₂ O

wherein a ranges from 0.5 to 2, b ranges from 0.1 to 0.8, c′ ranges from 0.5 to 2, c″ ranges from 0.8 to 3.2, and d ranges from 75 to 300.

Specifically, a may range from 0.6 to 1.8, may range from 0.7 to 1.6, may range from 0.8 to 1.4, may range from 0.8 to 1.2, or may range from 0.9 to 1.1.

In addition, b may be in the range of 0.15 to 0.75, may be in the range of 0.20 to 0.70, may be in the range of 0.25 to 0.65, may be in the range of 0.27 to 0.60, may be in the range of 0.30 to 0.55, may be in the range of 0.33 to 0.50, and may range from 0.35 to 0.40.

In addition, c' may be in the range of 0.6 to 1.8, may be in the range of 0.7 to 1.6, may be in the range of 0.8 to 1.4, may be in the range of 0.8 to 1.2, and may be in the range of 0.9 to 1.1.

In addition, c″ may be in the range of 0.9 to 3.0, may be in the range of 1.0 to 2.8, may be in the range of 1.1 to 2.6, may be in the range of 1.2 to 2.4, may be in the range of 1.3 to 2.2, , may range from 1.4 to 2.0, may range from 1.4 to 1.8, and may range from 1.5 to 1.7.

In addition, d may be in the range of 90 to 270, may be in the range of 105 to 240, may be in the range of 130 to 210, may be in the range of 145 to 180, and may be in the range of 145 to 155.

Furthermore, the step of preparing the SAPO-34 growth solution,

preparing a mixture of at least one aluminum source, at least one phosphorus source, and water;

adding at least one silicon source to the mixture;

adding at least one first organic template to the mixture;

adding at least one second organic template to the mixture; and

It may include; hydrothermally treating the mixture.

In the step of preparing a mixture of the at least one aluminum source, at least a phosphorus source, and water, the preparation of the mixture is performed at a temperature range of 20 ° C to 40 ° C and 25 ° C to 35 ° C for 60 minutes to 240 minutes and 90 minutes to 180 minutes It can be.

In the step of adding at least one silicon source to the mixture, a stirring process for mixing may be performed after the addition, and at a temperature range of 20 ° C to 40 ° C, 25 ° C to 35 ° C, 30 minutes to 120 minutes, 45 minutes to 45 minutes It can be done for 90 minutes.

In the step of adding at least one first organic template to the mixture, tetraethylammonium hydroxide may be applied as the first organic template, a stirring process for mixing may be performed after addition, and a temperature of 20 ° C to 40 ℃, it may be carried out for 30 minutes to 120 minutes, 45 minutes to 90 minutes at a temperature range of 25 ℃ to 35 ℃.

In the step of adding at least one second organic template to the mixture, dipropylamine may be applied as the second organic template, a stirring process for mixing may be performed after the addition, and a temperature of 20 ° C to 40 ° C, 25 It may be carried out for 30 minutes to 120 minutes, 45 minutes to 90 minutes at a temperature range of ℃ to 35 ℃.

The hydrothermal treatment is 6 at a temperature range of 35 ℃ to 80 ℃, 37 ℃ to 75 ℃, 39 ℃ to 70 ℃, 41 ℃ to 65 ℃, 43 ℃ to 60 ℃, 45 ℃ to 55 ℃, 47 ℃ to 53 ℃ It is preferably performed for 10 hours to 24 hours, 10 hours to 20 hours, 12 hours to 18 hours, and 16 hours to 18 hours.

Next, the manufacturing method of the SAPO-34 composite membrane provided in one aspect of the present invention includes immersing the support in the SAPO-34 seed solution.

The composite membrane has a support/SAPO-34 zeolite layer structure prepared by forming a SAPO-34 zeolite layer on a support, and first, the support is immersed using a SAPO-34 seed solution.

The support is a ceramic support and is preferably in the form of a hollow fiber. The ceramics include α-alumina, γ-alumina, polypropylene, polyethylene, polytetrafluoroethylene, polysulfone, polyimide, silica, glass, mullite, zirconia, titania, and yttria. (yttria), ceria, vanadia, silicon, stainless steel, carbon, calcium oxide and phosphorus oxide, and the like.

The immersion may be performed for 30 seconds to 600 seconds, may be performed for 45 seconds to 300 seconds, may be performed for 50 seconds to 200 seconds, and may be performed for 55 seconds to 100 seconds.

The step of immersing the support in the SAPO-34 seed solution may be repeatedly performed, specifically, immersing for 30 seconds to 600 seconds and drying at a temperature of 60 ° C to 180 ° C and 90 ° C to 120 ° C. can be done by

In addition, after performing the step of immersing the support in the SAPO-34 seed solution, it is preferable to include the step of rubbing the immersed support. SAPO-34 seed crystals excessively attached to the support may be removed through rubbing.

Furthermore, the SAPO-34 seed formed on the support through the step of immersing the support in the SAPO-34 seed solution is in the form of nanoparticles, may be 0.005 μm to 0.1 μm, may be 0.01 μm to 0.05 μm, and may be 0.01 μm to 0.03 μm. μm.

In addition, the support may have a pore size of 0.01 μm or less, 0.001 μm to 0.01 μm, 0.002 μm to 0.009 μm, 0.003 μm to 0.008 μm, 0.004 μm, 0.007 μm, and 0.005 μm. It may be ㎛ to 0.006 ㎛, may be 0.005 ㎛ to 0.01 ㎛, may be 0.006 ㎛ to 0.01 ㎛, may be 0.007 ㎛ to 0.01 ㎛.

As described above, nanoparticle seeds having a size of 0.005 μm to 0.1 μm, preferably 0.01 μm and 0.05 μm may be formed by immersing the SAPO-34 seed solution in the support having a pore size of 0.01 μm or less.

Next, the manufacturing method of the SAPO-34 composite membrane provided in one aspect of the present invention includes calcining the support.

In this step, the support containing the seed crystals is calcined by dipping into the SAPO-34 seed solution.

The calcination may be performed for 30 minutes to 600 minutes, 60 minutes to 300 minutes, and 90 minutes to 270 minutes at a temperature range of 400 ℃ to 600 ℃, 450 ℃ to 550 ℃.

Next, the manufacturing method of the SAPO-34 composite membrane provided in one aspect of the present invention includes hydrothermal synthesis by immersing the support in the SAPO-34 growth solution.

In the above step, the support is put into the SAPO-34 growth solution to grow the SAPO-34 seed crystals formed on the support.

The hydrothermal synthesis may be performed at a temperature range of 120°C to 180°C, 140°C to 180°C, and 160°C to 180°C for 4 hours to 36 hours, 6 hours to 24 hours, and 8 hours to 12 hours.

In addition, after performing the hydrothermal synthesis step, the support is heated to a temperature of 350 ° C to 550 ° C, 380 ° C to 500 ° C, 400 ° C to 450 ° C for 30 minutes to 120 minutes, 45 minutes to 90 minutes, 50 minutes to 50 minutes. A step of heating for 70 minutes to remove the organic template may be further included.

Further, the thickness of the SAPO-34 zeolite layer grown from the seed through hydrothermal synthesis may be 0.01 μm to 3 μm, 0.01 μm to 2 μm, 0.01 μm to 1 μm, and 0.01 μm to 0.5 μm. , may be 0.01 μm to 0.2 μm, may be 0.01 μm to 0.1 μm, may be 0.01 μm to 0.05 μm, may be 0.05 μm to 2.8 μm, may be 0.08 μm to 2.5 μm, may be 0.1 μm μm to 2.5 μm.

Also, in another aspect of the present invention

It is produced by the above manufacturing method,

A support and a SAPO-34 zeolite layer formed on the surface of the support,

The thickness of the SAPO-34 zeolite layer is provided with a silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that 0.01 ㎛ to 3 ㎛.

In the composite membrane provided by the manufacturing method provided in one aspect of the present invention, the thickness of the SAPO-34 zeolite layer may be formed to be 0.1 μm to 3 μm, and thus has high nitrogen / methane selectivity as well as excellent nitrogen permeability can indicate

The thickness of the SAPO-34 zeolite layer is preferably 0.01 μm to less than 3 μm, preferably 0.05 μm to 2.8 μm, preferably 0.08 μm to 2.5 μm, and preferably 0.1 μm to 2.5 μm.

Furthermore, in another aspect of the present invention

A support and a SAPO-34 zeolite layer formed on the surface of the support,

The thickness of the SAPO-34 zeolite layer is 0.01 μm to 3 μm,

Silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that it is applied for separation between gases selected from the group consisting of nitrogen / methane separation, hydrogen / carbon dioxide separation, hydrogen / methane separation and hydrogen / nitrogen separation Provided.

The SAPO-34 composite membrane provided in another aspect of the present invention maintains a nitrogen/methane selectivity of 7 or more and has a nitrogen permeability of more than 100 GPU, and thus has excellent gas separation performance.

Hereinafter, the present invention will be described in detail through examples and experimental examples.

However, the following Examples and Experimental Examples are only for explaining the present invention, and the content of the present invention is not limited by the following Examples and Experimental Examples.

<Example 1>

SAPO-34 seed solution preparation

4.63 g of aluminum-isopropoxide, 18.68 g of tetraethylammonium hydroxide (TEAOH), and 1.381 g of water (DI water) were mixed in this order and stirred for 2 hours (Oil bath 30 ° C, 1000 rpm ). For reproducibility, a conical tube was used, aluminum isopropoxide was prepared by grinding as finely as possible, and it was confirmed that the solution became transparent after 30 minutes.

1 g of AS-40 (LUDOX) was added to the mixture as a silicon source and stirred for 1 hour (Oil bath 30° C., 1000 rpm).

Phosphoric acid in the mixture (H ₃ PO ₄ ) After dropping 5.12 g slowly dropwise over 30 minutes, the mixture was stirred for 3 days (Oil bath 30° C., 1000 rpm).

The mixture was hydrothermally synthesized at 180 °C for 2 days to prepare a SAPO-34 seed solution.

Preparing the SAPO-34 growth solution

52.39 g of water (DI water), 5.12 g of phosphoric acid (H ₃ PO ₄ ), and 9.25 g of aluminum-isopropoxide were mixed in this order and stirred for 2 hours (30° C., 1000 rpm).

1.20 g of AS-40 (LUDOX) was added to the mixture as a silicon source and stirred for 1 hour (30° C., 1000 rpm).

9.34 g of tetraethylammonium hydroxide (TEAOH) was added to the mixture and stirred for 1 hour (30° C., 1000 rpm).

3.63 g of dipropylamine (DPA) was added to the mixture and stirred for 1 hour (30° C., 1000 rpm).

The mixture was subjected to hydrothermal treatment while stirring at a temperature of 50 ° C. for 17 hours to prepare a SAPO-34 growth solution.

Manufacture of SAPO-34 composite membrane

An alumina hollow fiber was prepared as a support, and both the front and back sides were blocked with Teflon tape.

After immersing the alumina hollow fiber in the SAPO-34 seed solution prepared above for about 1 minute, it was dried in an oven at 120° C. for 30 minutes. This was repeated twice. Thereafter, seed crystals excessively attached to the alumina hollow fibers were removed through rubbing.

Thereafter, the support was calcined at a temperature of 500° C. for 3 hours.

Thereafter, the scaffold was immersed in the SAPO-34 growth solution prepared above, and hydrothermal synthesis was performed at a temperature of 180° C. for 10 hours.

Finally, the organic template was removed by treating the support at a temperature of 420° C. (1° C./min) for 1 hour, and a SAPO-34 composite membrane was prepared.

<Experimental Example 1> Morphology analysis

The seed crystals of the SAPO-34 seed solution prepared in Example 1 were analyzed with a scanning electron microscope (SEM) and shown in FIG. 1, and the SAPO-34 composite film prepared in Example 1 was analyzed with a scanning electron microscope (SEM). shown in Figure 2.

As shown in FIG. 1, it was confirmed that seed crystals formed through the SAPO-34 seed solution.

As shown in FIG. 2, it was confirmed that a SAPO-34 zeolite layer having a thickness of about 0.1 to 3 μm was formed in the SAPO-34 composite membrane.

<Experimental Example 2> Composite membrane performance analysis

Single gas separation performance was measured using the 0.1 μm to 3 μm SAPO-34 composite membrane of Example 1. The gas permeability and selectivity of carbon dioxide (CO ₂ ), nitrogen (N ₂ ), methane (CH ₄ ), and hydrogen (H ₂ ) were analyzed through the equation below, and the results are shown in Table 1.

<expression>

Permeance (GPU) = 10 ⁶ × Volume flow rate (cm ³ /s) / Pressure (cmHg) × Membrane area (cm ² )

Types of permeating gases CO ₂ N ₂ CH ₄ H ₂ Gas permeation measurement temperature (25℃) permeability
(GPUs) 3,560~60,720 119~1,020 16.5 to 68.9 1,830~10,150 selectivity N ₂ /CH ₄ = 7.2 to 14.8

As shown in Table 1, the SAPO-34 composite membrane exhibits excellent nitrogen/methane selectivity of 7.2 to 14.8 and GPU nitrogen permeability of 119 to 1,020 as the thickness of the coating layer varies from 0.1 μm to 3 μm at a temperature of 25 ° C. It was confirmed that methane separation properties were exhibited.

Claims (15)

preparing a SAPO-34 seed solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;
preparing a SAPO-34 growth solution comprising at least one aluminum source, at least one phosphorus source, at least one silicon source, at least one organic template and water;
immersing the support in the SAPO-34 seed solution;
calcining the support; and
Method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of hydrothermal synthesis by immersing the support in the SAPO-34 growth solution.
According to claim 1,
The composite membrane is at least one composite membrane selected from the group consisting of a composite membrane for nitrogen / methane separation, a composite membrane for hydrogen / carbon dioxide separation, a composite membrane for hydrogen / methane separation, and a composite membrane for hydrogen / nitrogen separation Silicoaluminophosphate Method for manufacturing a -34 (SAPO-34) composite membrane.
According to claim 1,
The step of preparing the SAPO-34 seed solution,
preparing a mixture of at least one aluminum source, at least one organic mold and water;
adding at least one silicon source to the mixture;
adding at least one phosphorus source to the mixture; and
Method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of hydrothermal synthesis of the mixture.
According to claim 1,
The method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane in which the SAPO-34 seed solution has the following molar composition:
1 Al ₂ O ₃ : a P ₂ O ₅ : b SiO ₂ : c Organic template : d H ₂ O
where a ranges from 1 to 3, b ranges from 0.3 to 0.9, c ranges from 2 to 8, and d ranges from 30 to 150.
According to claim 3,
The hydrothermal synthesis is a method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane that is carried out for 12 hours to 60 hours at a temperature range of 120 ℃ to 180 ℃.
According to claim 1,
The step of preparing the SAPO-34 growth solution,
preparing a mixture of at least one aluminum source, at least one phosphorus source, and water;
adding at least one silicon source to the mixture;
adding at least one first organic template to the mixture;
adding at least one second organic template to the mixture; and
Method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of hydrothermal treatment of the mixture.
According to claim 1,
The manufacturing method of the silicoaluminophosphate-34 (SAPO-34) composite membrane, wherein the SAPO-34 growth solution has the following molar composition:
1 Al ₂ O ₃ : a P ₂ O ₅ : b SiO ₂ : c' first organic template: c'' second organic template: d H ₂ O
wherein a ranges from 0.5 to 2, b ranges from 0.1 to 0.8, c′ ranges from 0.5 to 2, c″ ranges from 0.8 to 3.2, and d ranges from 75 to 300.
According to claim 6,
The hydrothermal treatment is a method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane that is performed for 6 hours to 24 hours at a temperature range of 35 ℃ to 80 ℃.
According to claim 1,
The method of manufacturing a silicoaluminophosphate-34 (SAPO-34) composite membrane in which the support is a ceramic support and is in the form of a hollow fiber.
According to claim 1,
A method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane comprising the step of immersing the support in the SAPO-34 seed solution and then rubbing the immersed support.
According to claim 1,
The calcination is a method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane that is carried out for 30 minutes to 600 minutes at a temperature range of 400 ℃ to 600 ℃.
According to claim 1,
The hydrothermal synthesis is a method for producing a silicoaluminophosphate-34 (SAPO-34) composite membrane that is carried out for 4 hours to 36 hours at a temperature range of 120 ℃ to 180 ℃.
According to claim 1,
After performing the hydrothermal synthesis step, the support is heated at a temperature of 350 ° C to 550 ° C for 30 minutes to 120 minutes to remove the organic template. ) Manufacturing method of composite membrane.
It is produced by the manufacturing method of claim 1,
A support and a SAPO-34 zeolite layer formed on the surface of the support,
Silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that the thickness of the SAPO-34 zeolite layer is 0.01 ㎛ to 3 ㎛.
A support and a SAPO-34 zeolite layer formed on the surface of the support,
The thickness of the SAPO-34 zeolite layer is 0.01 μm to 3 μm,
Silicoaluminophosphate-34 (SAPO-34) composite membrane, characterized in that it is applied for separation between gases selected from the group consisting of nitrogen / methane separation, hydrogen / carbon dioxide separation, hydrogen / methane separation and hydrogen / nitrogen separation .

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