Membrane for water condensation, method for manufacturing same, and method for dehumidifying gas

Abstract

Disclosed is a membrane capable of removing vapor contained in gas. According to an aspect of the present invention, provided is a membrane for water condensation, comprising: a support including a first region and a second region on the first region; and a coating layer on the support, the first region including pores with a finger-like structure, and the second region including pores with a sponge-like structure, wherein the coating layer contains any one selected from the group consisting of a silane-based compound, zeolite, and a combination thereof.

Description

Separation membrane for moisture condensation, method for manufacturing the same, and method for dehumidifying gas

[0001] The present disclosure relates to a separation membrane for moisture condensation, and more specifically, to a separation membrane for moisture condensation, a method for manufacturing the same, and a method for dehumidifying gas.

[0002] In addition to effectively removing moisture contained in combustion exhaust gases, indoor air in automobiles / buildings, outdoor air, and industrial gas streams, the importance of dehumidification in gas streams generated at industrial sites, such as combustion exhaust gases, is increasing.

[0003] Dehumidification is typically achieved using heat exchangers or absorption methods, but these methods suffer from the drawback of being energy-intensive processes. Therefore, various membrane-based methods have recently been proposed, including Dense Membrane Condenser (DMC), Transport Membrane Condenser (TMC), and Membrane Condenser (MC) membranes.

[0004] DMC membranes have a low processing speed due to their dense nature, while TMC membranes are hydrophilic membranes, with their pores condensed with water, resulting in low permeability. MC membranes utilize hydrophobic ceramics (alumina), PVDF (Polyvinylidene Fluoride), ECTFE (Ethylene chlorotrifluoroethylene), and ETFE (Ethylene tetrafluoroethylene), among which ceramic membranes are known to have the highest water rejection.

[0005] According to one aspect of the present invention, a separation membrane for moisture condensation is provided that can increase the permeability of dehumidified gas and at the same time increase the efficiency of removing water from a gas containing water vapor.

[0006] According to another aspect of the present invention, a method for manufacturing the above-described moisture condensation membrane is provided.

[0007] According to another aspect of the present invention, a method for dehumidifying a gas using the above moisture condensation membrane is provided.

[0008] The purposes of the present invention are not limited to those mentioned above, and other unmentioned purposes and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof described in the specification.

[0009] According to a first aspect of the present invention, a water condensation separation membrane is provided, comprising: a support including a first region and a second region on the first region; and a coating layer on the support; wherein the first region includes pores of a finger-like structure, the second region includes pores of a sponge-like structure, and the coating layer includes any one selected from the group consisting of a silane compound, a zeolite, and a combination thereof. Here, "a combination thereof" may mean a state in which the zeolite is physically mixed with the silane compound, a state in which the zeolite is separated from each other by layers, or a state in which the zeolite is chemically bonded.

[0010] According to a second aspect of the present invention, in the first aspect, the second region may be disposed between the first region and the coating layer.

[0011] According to a third aspect of the present invention, in the first or second aspect, the average diameter of the pores included in the first region may be 150 µm or more and 200 µm or less in the long axis and 10 µm or more and 30 µm or less in the short axis, and the average diameter of the pores included in the second region may be 0.1 µm or more and 1.5 µm or less.

[0012] According to a fourth aspect of the present invention, in any one of the first to third aspects, the support may include a ceramic support.

[0013] According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the silane compound is selected from the group consisting of trimethoxy(propyl)silane, hexadecyltrimethoxysilane, isobutyl(trimethoxy)silane, trimethoxy(octyl)silane, trimethoxy(octadecyl)silane, [3-(Diethylamino)propyl]trimethoxysilane, (N,N-dimethylaminopropyl)trimethoxysilane, Trimethoxy(3,3,3-trifluoropropyl)silane, Trimethoxy(2-phenylethyl)silane, Trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, n-Propyltriethoxysilane, Triethoxy(isobutyl)silane, Triethoxy(pentyl)silane, Triethoxy(hexyl)silane, Triethoxy(octyl)silane, It may include at least one selected from the group consisting of N-octadecyltriethoxysilane, cyclopentyltriethoxysilane, and (triethoxysilyl)cyclohexane.

[0014] According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the zeolite may include a hydrophobic zeolite having a Si / Al ratio of 1,000 or more.

[0015] According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the coating layer includes a first layer and a second layer on the first layer, the first layer is disposed between the second region and the second layer, the first layer includes a zeolite thin film in which the zeolite is secondarily grown, and the second layer may include the silane-based compound. Specifically, since the zeolite thin film includes a zeolite that has been secondarily grown, the ratio of the standard deviation of the thickness to the average thickness of the zeolite thin film may be 1% or less, 0.5% or less, or 0.1% or less. If the second growth process is not performed, the ratio of the standard deviation of the thickness to the average thickness of the zeolite thin film may be outside the above numerical range. Here, the ratio of the standard deviation of the thickness to the average thickness of the zeolite thin film is an indicator of the uniformity of the thin film surface, and a lower value thereof may mean that the thin film surface is more uniform. For example, the ratio of the standard deviation of the thickness to the average thickness of the zeolite thin film can be analyzed by measuring the thickness at each of 50 arbitrary points of the thin film using any one method selected from the group consisting of scanning electron microscopy, atomic force microscopy, and combinations thereof.

[0016] According to an eighth aspect of the present invention, there is provided a method comprising: (S1) preparing a dope solution comprising a polymer solution, a binder, alpha-alumina, and gamma-alumina; (S2) spinning the dope solution to produce hollow fibers; (S3) immersing the hollow fibers in a non-solvent to produce solidified hollow fibers; (S4) drying the solidified hollow fibers and then sintering the dried hollow fibers to produce a support; And (S5) a step of forming a coating layer on at least one surface of the support, wherein the support includes a first region and a second region on the first region, the first region includes pores of a finger-like structure, and the second region includes pores of a sponge-like structure, and the content of the gamma-alumina is 1 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the total sum of the content of the alpha-alumina and the content of the gamma-alumina, and the coating layer includes any one selected from the group consisting of a silane compound, a zeolite, and a combination thereof. Here, an eighth aspect of the present invention may be characterized by any one or more of the first to seventh aspects; or some embodiments of the present specification.

[0017] According to a ninth aspect of the present invention, in the eighth aspect, the step (S5) may include a step of immersing the support in a zeolite dispersion and then drying it, a step of immersing the immersed and dried support in a hydrothermal solution to produce a preliminary separation membrane, and a step of immersing the preliminary separation membrane in a silane solution and then drying it to produce a separation membrane for water condensation. For example, by immersing the immersed and dried support in a hydrothermal solution, a secondary growth process of zeolite may proceed, thereby forming a zeolite thin film.

[0018] According to a tenth aspect of the present invention, a method for dehumidifying a gas using a moisture condensation separation membrane according to any one of the first to seventh aspects is provided.

[0019] The solutions to the above problems do not enumerate all the features of the present invention. The various features of the present invention, along with their corresponding advantages and effects, can be understood in more detail by referring to the detailed description below.

[0020] According to one aspect of the present invention, a moisture condensation separation membrane can be implemented that can increase the permeability of dehumidified gas and at the same time increase the efficiency of removing water from a gas containing water vapor.

[0021] According to another aspect of the present invention, a dehumidification method applicable to various real-life or industrial fields can be implemented using the above moisture condensation separation membrane.

[0022] In addition to the aforementioned effects, the specific effects of the present invention are described below along with the specific details for implementing the invention. Furthermore, the effects of the present invention are not limited to the effects described above and can be readily achieved by the means and combinations thereof described in the specification.

[0023] Figure 1a is a schematic diagram of a moisture condensation separation membrane according to one embodiment of the present invention.

[0024] Figure 1b is a schematic diagram of a moisture condensation separation membrane according to another embodiment of the present invention.

[0025] Figure 2 is a schematic diagram showing a gas dehumidification method according to one embodiment of the present invention.

[0026] Figure 3 is a SEM (Scanning Electron Microscope) photograph of the bending strength of the support according to Manufacturing Preparation Examples 1-1 to 1-4 and the support according to Manufacturing Preparation Examples 1-2 and 1-4.

[0027] Figure 4 shows the contact angle results of water droplets on the surface of the separation membrane according to Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, and 5-1 to 5-4.

[0028] Figure 5 is a graph showing nitrogen permeability according to the steam condensation time of the separation membrane according to Comparative Example 1 and Example 3-2.

[0029] Figure 6a is a graph showing the moisture removal rate according to the water vapor condensation time of the separation membrane according to Comparative Example 1 and Example 3-2. Figure 6b is a photograph showing the contact angle of a water droplet on the surface of the separation membrane according to Comparative Example 1. Figure 6c is a photograph showing the contact angle of a water droplet on the surface of the separation membrane according to Example 3-2.

[0030] Figure 7a is a graph showing the moisture removal rate according to the feed pressure of the separation membranes of Comparative Example 1, Example 3-1, and Example 8.

[0031] Figure 7b is a graph showing the nitrogen permeability according to the feed pressure of the separation membranes of Comparative Example 1, Example 3-1, and Example 8.

[0032] Figure 8 is a graph showing nitrogen permeability according to feed pressure of the separation membrane according to Examples 7 and 9-1 to 9-3.

[0033] Figure 9 is a graph showing the moisture removal rate according to the feed pressure of the separation membrane according to Examples 7 and 9-1 to 9-3.

[0034] Figure 10 shows SEM photographs of the membranes according to Examples 7 and 9-1 to 9-3 and the contact angle results for water droplets.

[0035] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0036] In this specification, expressions such as “first,” “second,” “first,” “second,” “(S1),” “(S2),” etc., may describe various components, regardless of order and / or importance, and do not limit the components. These expressions may be used to distinguish one component from another. For example, without departing from the scope of the present disclosure, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

[0037] The terms "comprise" and / or "comprising" in this specification specify the presence of stated features, steps, numbers, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, numbers, operations, elements, elements and / or groups thereof.

[0038] In this specification, “At least one of a, b and c” may include a, b or c alone, or a combination of two or more selected from the group consisting of a, b and c.

[0039] If multiple embodiments are described in this specification, the embodiments may be combined unless specifically stated otherwise. In this case, the effects of the present invention may be defined as including the effects derived from each embodiment and the effects resulting from the organic combination of the embodiments. For example, even if Embodiments 1 and 2 are described independently in this specification, Embodiments 1 and 2 may be organically combined with each other, unless the context clearly indicates otherwise, and the effects of the present invention may include the effects resulting from the combination of Embodiments 1 and 2.

[0040] The numerical range indicated by the term "to" in this specification refers to a numerical range that includes the values ​​stated before and after the term as the lower and upper limits, respectively. For example, if "a" and "b" are stated in the specification, it can be understood that "a" and "b" are stated.

[0041] In the present specification, when multiple numerical values ​​are disclosed as the upper and lower limits of any numerical range, the numerical range disclosed in the present specification can be understood as any numerical range that has any one of the multiple lower limit values ​​and any one of the multiple upper limit values ​​as the lower limit value and the upper limit value, respectively. For example, when a or more, or b or more; and c or less or d or less are described, it can be understood that a or more and c or less, a or more and d or less, b or more and c or less, or b or more and d or less are described.

[0042] As used herein, terms such as "about" or "substantially" mean a reasonable amount of variation from the term that does not significantly alter the final result. These terms may be interpreted to include a variation of at least ±5% or at least ±10%, provided that such variation does not alter the meaning of the term and render it invalid.

[0043] In this specification, the term "layer" or film may include cases where it is formed not only over the entire area when observing the area where the layer or film exists, but also cases where it is formed over only a portion of the area. For example, the surface of the layer or film may be defined to include a flat shape, a non-flat shape, and a combination thereof; or a continuous shape, a discontinuous shape, and a combination thereof. For example, when another element is formed as a layer or film directly on top of one element, the coverage of the other element on the surface of the one element may be defined as 1% or more, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 99% or more.

[0044] In this specification, the average particle diameter of the particles is the particle diameter (D) when the cumulative percentage in the volume-based particle size distribution curve is 50% when measured by a laser diffraction particle size distribution measuring device. 50 ) can be defined. For example, the average particle diameter of the particles can be calculated by dispersing the target particles in a dispersion medium, introducing them into a commercially available laser diffraction particle size measuring device (e.g., Microtrac S3500), and measuring the difference in diffraction pattern according to particle size when the particles pass through a laser beam.

[0045] In this specification, "weight average molecular weight" or "number average molecular weight" refers to a standard polystyrene-converted molecular weight, which can be analyzed using a GPC (Gel permeation chromatography) device. For example, in the case of a GPC analysis method, the developing solvent may be Tetrahydrofuran (THF), the column may be PL Olexis from Polymer Laboratories, the sample concentration may be 5 mg / mL, the sample injection amount may be 100 ㎕, the flow rate may be 1 mL / min, the detector may be Agilent High Temperature RI detector, and the column temperature may be set to 40°C.

[0046] In this specification, the term "nonsolvent-induced phase separation (NIPS) method" may refer to a process in which a uniformly mixed, homogeneous solution comes into contact with a nonsolvent, thereby causing a solvent-nonsolvent material exchange. This causes phase separation, thereby inducing solidification.

[0047] In this specification, the term "finger-like structure" may refer to a shape in which finger-shaped pores are formed when a cross-section of a support is observed under a microscope. For example, the pores of the above-mentioned finger-like structure may have different sizes depending on the short-axis and long-axis directions. For example, the finger-like pores may have a ratio of the long-axis length to the short-axis length of 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more.

[0048] In this specification, the term "sponge-like structure" may refer to a pore structure in which spherical or bead-shaped pores are densely formed when observing a cross-section of a support through a microscope photograph. For example, the spherical or bead-shaped pores may have a ratio of the major axis length to the minor axis length of 1 or more and less than 2, or 1 or more and less than 1.5.

[0049] As used herein, “zeolite” refers to a porous aluminosilicate composite oxide, which may include a structure having at least one of LTL, VFI, MAZ, MEI, FAU, EMT, OFF, BEA, MOR, MFI, MFS, MEL, MTW, EUO, MTT, HEU, FER, TON, CHA, ERI, KFI, LEV, and LTA.

[0050] According to one aspect of the present invention, a moisture condensation separation membrane is provided, comprising: a support including a first region and a second region on the first region; and a coating layer on the support; wherein the first region includes pores having a finger-like structure, the second region includes pores having a sponge-like structure, and the coating layer includes any one selected from the group consisting of silane compounds, zeolites, and combinations thereof. According to one aspect of the present invention, since the membrane has both pores having a finger-like structure and pores having a sponge-like structure, and the coating layer includes any one selected from the group consisting of silane compounds, zeolites, and combinations thereof, it is possible to implement an effect of increasing the permeability of a dehumidified gas and simultaneously increasing the water removal efficiency. Specifically, by including one selected from the group consisting of a silane compound, a zeolite, and a combination thereof in the coating layer, the hydrophobicity of the surface of the moisture condensation membrane can be further increased, so that the moisture condensation effect can be more excellently expressed. In addition, by including pores of a finger-like structure inside the support, the dehumidified gas permeability can be further increased, and by including pores of a sponge-like structure inside the support, the mechanical properties of the support can be improved within a limit that does not significantly reduce the dehumidified gas permeability.

[0051] Hereinafter, the configuration of the present invention will be described in more detail with reference to the drawings.

[0052] 1. Separator for moisture condensation

[0053] Figure 1a is a schematic diagram of a moisture condensation separation membrane according to one embodiment of the present invention.

[0054] Referring to FIG. 1a, a moisture condensation separation membrane (100) according to the present invention includes a support (10) and a coating layer (20).

[0055] Support (10)

[0056] The support (10) according to the present invention can serve as a substrate for forming a coating layer while increasing gas permeability by including a porous structure having pores within it. For example, the support (10) may be a membrane-shaped support and include a plurality of hollow fibers with an empty interior.

[0057] The first region (10a) according to the present invention can increase the permeability of the dehumidified gas by including pores of a finger-like structure.

[0058] In some embodiments of the present invention, the thickness of the first region (10a) may be 150 to 300 μm, 160 to 290 μm, 170 to 280 μm, 180 to 270 μm, 190 to 260 μm, 190 to 210 μm, 195 to 205 μm, and most preferably 200 to 202 μm. According to some embodiments of the present invention, when the thickness of the first region is less than the above numerical range, a problem may arise in that the permeability of the dehumidified gas is not sufficiently increased, and when it exceeds the above numerical range, the permeability of the dehumidified gas may be increased, but a problem may arise in that the mechanical properties of the support are deteriorated.

[0059] In some embodiments of the present invention, the porosity of the first region (10a) may be 60 to 80%, 65 to 75%, 67 to 73%, 68 to 72%, 69 to 71%, and most preferably 70 to 71%. Specifically, the porosity of the first region (10a) may refer to the ratio of the volume occupied by pores to the total volume of the first region. According to some embodiments of the present invention, when the porosity of the first region is less than the above numerical range, a problem may occur in which the permeability of the dehumidified gas is not sufficiently increased, and when it exceeds the above numerical range, a problem may occur in which the mechanical properties of the support are deteriorated.

[0060] Meanwhile, since the pores included in the first region (10) have a ground structure, their diameters may differ depending on the major and minor axes. In some embodiments of the present invention, the average diameter of the pores included in the first region (10a) may be 150 to 200 μm, 160 to 190 μm, 170 to 180 μm, and most preferably 170 to 175 μm based on the major axis, and may be 10 to 30 μm, 15 to 25 μm, and most preferably 18 to 22 μm based on the minor axis. According to some embodiments of the present invention, when the average diameter of the pores included in the first region (10a) is less than the above numerical range, a problem may arise in which the permeability of the dehumidified gas is not sufficiently increased, and when it exceeds the above numerical range, a problem may arise in which the mechanical properties of the support are deteriorated.

[0061] The second region (10b) according to the present invention can further improve the mechanical properties of the support by including pores of a dense network structure (sponge-like structure) inside the support (10). If the second region does not include pores of a network structure, the permeability of the dehumidified gas can be increased, but the mechanical properties of the support can be significantly reduced, which can cause a problem in that the support cannot function as a substrate for the coating layer. That is, by including pores of a finger-like structure inside the support, the permeability of the dehumidified gas can be further increased, and by including pores of a network structure (sponge-like structure) inside the support, the mechanical properties of the support can be improved within a limit that does not significantly reduce the permeability of the dehumidified gas.

[0062] In some embodiments of the present invention, the second region (10b) may be disposed between the first region (10a) and the coating layer (20), and more specifically, may be disposed directly on the first region (10a). According to some embodiments of the present invention, the second region (10b) may be disposed between the first region (10a) and the coating layer (20), thereby serving as a substrate having mechanical properties capable of supporting the weight of the coating layer.

[0063] In some embodiments of the present invention, the thickness of the second region (10b) may be 150 to 300 μm, 160 to 290 μm, 170 to 280 μm, 180 to 270 μm, 190 to 260 μm, 190 to 210 μm, 195 to 205 μm, and most preferably 200 to 202 μm. According to some embodiments of the present invention, when the thickness of the second region is less than the above numerical range, the mechanical properties of the support may not be sufficiently improved, which may cause a problem of lowering the durability of the separation membrane, and when it exceeds the above numerical range, the problem of lowering the permeability of the dehumidified gas may occur.

[0064] In some embodiments of the present invention, the porosity of the second region (10b) may be 35 to 55%, 36 to 54%, 37 to 53%, 38 to 52%, 39 to 50%, 40 to 45%, or 40 to 43%, most preferably 40 to 41%. Specifically, the porosity of the second region (10b) may refer to the ratio of the volume occupied by pores to the total volume of the second region. According to some embodiments of the present invention, when the porosity of the second region is less than the above numerical range, a problem may occur in which the permeability of the dehumidified gas is not sufficiently increased, and when it exceeds the above numerical range, the permeability of the dehumidified gas may be increased, but a problem may occur in which the mechanical properties of the support are deteriorated.

[0065] In some embodiments of the present invention, the average diameter of the pores included in the second region (10b) may be 0.1 to 1.5 μm, 0.2 to 1.4 μm, 0.3 to 1.3 μm, 0.4 to 1.2 μm, 0.4 to 1.0 μm, 0.4 to 0.8 μm, 0.4 to 0.6 μm, and most preferably 0.4 to 0.5 μm. According to some embodiments of the present invention, when the average size of the pores having the network structure is less than the above numerical range, a problem may arise in that the permeability of the dehumidified gas is not sufficiently increased, and when it exceeds the above numerical range, the permeability of the dehumidified gas may be increased, but a problem may arise in that the mechanical properties of the support are deteriorated.

[0066] In some embodiments of the present invention, the thickness ratio (first region: second region) of the first region (10a) and the second region (10b) may be 1:0.7 to 1:1.3, 1:0.8 to 1:1.2, 1:0.9 to 1:1.1, and most preferably 1:1. According to some embodiments of the present invention, when the thickness ratio of the first region and the second region is outside the above numerical range, a problem may occur in at least one of the mechanical properties of the support and the permeability of the dehumidified gas.

[0067] In some embodiments of the present invention, the support (10) may include a ceramic support. For example, the ceramic support may include at least one selected from the group consisting of alpha-alumina, gamma-alumina, TiO2, ZrO2, SiC, and a silica-alumina composite, and specifically may include alpha-alumina and gamma-alumina. According to some embodiments of the present invention, since the support includes alpha-alumina and gamma-alumina, not only is the chemical stability excellent, but also the water condensation efficiency for a gas containing water vapor can be further improved. For example, the support may be a tubular capillary made of alpha-alumina material.

[0068] In some examples, the flexural strength of the support (10) measured using a three-point bending tester (H25KS, Hounsfield, England) may be 80 to 120 MPa, or 97 to 115 MPa.

[0069] In some examples, the porosity of the support (10) may be 48 to 52%, or 48 to 50%.

[0070] In some examples, the bulk density of the support (10) is 1.0 to 3.0 g / cm 3 , 1.0 to 2.0 g / cm 3 or 1.7 to 1.9 g / cm 3 It could be.

[0071] Under the conditions that the injection temperature is 90°C, the relative humidity is 80 to 100%, the injection gas is 100 ccm, and the injection pressure is 1.5 bar, the water permeability of the support (10) according to some examples is 900 to 2900 L / m 2· It could be h.

[0072] In some examples, when nitrogen (N2) gas is flowed at a flow rate of 1,000 mL / min at 25°C for 1 hour, the nitrogen permeability of the support (10) may be 85,000 to 130,000 GPU.

[0073] In some examples, when nitrogen (N2) gas is flowed at a flow rate of 1,000 mL / min at 25°C for 1 hour, the nitrogen permeation rate of the support (10) may be 2.97E-05 to 4.27E-05.

[0074] Coating layer (20)

[0075] The coating layer (20) according to the present invention imparts hydrophobic properties to the surface of a separation membrane for moisture condensation, thereby enabling selective condensation of water vapor from a gas containing water vapor.

[0076] The coating layer (20) according to the present invention may include any one selected from the group consisting of silane compounds, zeolites, and combinations thereof, and specifically may include a combination thereof, in order to impart hydrophobicity to the surface of a moisture condensation membrane. According to some embodiments of the present invention, by including the combination of the silane compounds and zeolites in the coating layer, the superhydrophobic properties of the surface of the membrane may be further enhanced, thereby increasing the moisture removal rate. At this time, the permeability of the dehumidified gas may be achieved within a limit that does not significantly decrease.

[0077] Specifically, the above silane compound may mean a compound having an organic group having 1 or more carbon atoms in at least one of the four functional groups bonded to a silicon atom (Si).

[0078] In some examples, the silane compound may not be particularly limited as long as it is a substance that can impart hydrophobicity to the surface of a moisture condensation membrane, and specifically, trimethoxy(propyl)silane, hexadecyltrimethoxysilane, isobutyl(trimethoxy)silane, trimethoxy(octyl)silane, trimethoxy(octadecyl)silane, [3-(Diethylamino)propyl]trimethoxysilane, (N,N-dimethylaminopropyl)trimethoxysilane, Trimethoxy(3,3,3-trifluoropropyl)silane, Trimethoxy(2-phenylethyl)silane, Trimethoxy[2-(7-oxabicyclo[4,1,0]hept-3-yl)ethyl]silane.It may include at least one selected from the group consisting of [0] hept-3-yl) ethyl] silane, n-Propyltriethoxysilane, triethoxy(isobutyl)silane, triethoxy(pentyl)silane, triethoxy(hexyl)silane, triethoxy(octyl)silane, N-octadecyltriethoxysilane, cyclopentyltriethoxysilane, and (triethoxysilyl)cyclohexane, and more specifically, it may include trimethoxy(propyl)silane or hexadecyltrimethoxysilane. According to some embodiments of the present invention, by including trimethoxy(propyl)silane or hexadecyltrimethoxysilane in the silane compound, the effect of condensing water vapor can be better realized without impeding the flow of dehumidified gas.

[0079] In some examples, the zeolite is a porous aluminosilicate composite oxide, which may include at least one structure selected from the group consisting of LTL, VFI, MAZ, MEI, FAU, EMT, OFF, BEA, MOR, MFI, MFS, MEL, MTW, EUO, MTT, HEU, FER, TON, CHA, ERI, KFI, LEV, and LTA.

[0080] In some embodiments of the present invention, the zeolite may include a hydrophobic zeolite, and more specifically, may include a silicalite-based compound. Here, the hydrophobic zeolite may have a Si / Al ratio of 1,000 or more, preferably infinite. According to some embodiments of the present invention, by including the hydrophobic zeolite in the coating layer, the effect of condensing water vapor can be better implemented without impeding the flow of dehumidified gas.

[0081] Figure 1b is a schematic diagram of a moisture condensation separation membrane according to another embodiment of the present invention.

[0082] Referring to FIG. 1B, the coating layer according to the present invention may include a first layer and a second layer on the first layer. Specifically, the first layer may be disposed between the second region and the second layer. In some embodiments of the present invention, the first layer may include a zeolite, and the second layer may include a silane-based compound. Here, the zeolite and the silane-based compound may be chemically bonded to each other to form a covalent bond. According to some embodiments of the present invention, since the first layer includes a zeolite and the second layer includes a silane-based compound, the effect of condensing water vapor without impeding the flow of dehumidified gas can be better implemented.

[0083] In some embodiments of the present invention, the silane-based compound may be coated on the surface of the zeolite. For example, the silane-based compound may be coated on the surface of at least one particle among the plurality of zeolites, or may be coated on part or all of the surfaces of the zeolites. According to some embodiments of the present invention, by coating the silane-based compound on the surface of the zeolite, the hydrophobicity of the separation membrane is further enhanced, so that the effect of condensing water vapor can be better implemented.

[0084] In some embodiments of the present invention, the first layer may include a zeolite thin film in which the zeolite is secondarily grown, and the second layer may include the silane-based compound. According to some embodiments of the present invention, since the first layer includes a zeolite thin film in which the zeolite is secondarily grown, and the second layer includes the silane-based compound, the hydrophobicity of the separation membrane is further strengthened, and the effect of condensing water vapor can be better implemented.

[0085] In some embodiments of the present invention, the average spacing between any one grain and any other grain in the secondarily grown zeolite film may be 10 nm or more, 20 nm or more, 40 nm or more, 60 nm or more, 80 nm or more, 100 nm or more, 120 nm or more, 140 nm or more, 160 nm or more, 180 nm or more, or 190 nm or more, and specifically, any one or more of the plurality of lower limits may be 200 nm or less. Here, the average spacing between grains can be analyzed by SEM photography. In some embodiments of the present invention, by controlling the average spacing between grains within the above numerical range, the effect of condensing water vapor can be better implemented without impeding the flow of dehumidified gas. Alternatively, the average spacing between grains described above may be the diameter of a pore channel. For example, the average spacing between the grains described above may be the average spacing between the grain boundary of any one grain and the boundary of the grain closest to any one grain.

[0086] In some embodiments of the present invention, the thickness of the secondarily grown zeolite film may be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, or 9 μm or more, and specifically, any one or more of the plurality of lower limits may be 10 μm or less. In some embodiments of the present invention, by controlling the thickness of the secondarily grown zeolite film within the above numerical range, the effect of condensing water vapor without impeding the flow of dehumidified gas can be better implemented. That is, by simultaneously controlling the average spacing between grains and the thickness of the zeolite film within the above numerical range, a synergistic effect of condensing water vapor without impeding the flow of gas can be implemented. For example, the thickness of the secondarily grown zeolite film can be measured through an SEM photograph.

[0087] 2. Manufacturing method of a separation membrane for moisture condensation

[0088] According to another aspect of the present invention, there is provided a method for producing a hollow fiber, comprising: (S1) preparing a dope solution comprising a polymer solution, a binder, and alpha-alumina and gamma-alumina; (S2) spinning the dope solution to produce a hollow fiber; (S3) immersing the hollow fiber in a non-solvent to produce a solidified hollow fiber; (S4) drying the solidified hollow fiber and then sintering the dried hollow fiber to produce a support; and (S5) forming a coating layer on at least one surface of the support. A method for manufacturing a separation membrane for moisture condensation is provided, wherein the support includes a first region and a second region on the first region, the first region includes pores of a finger-like structure, the second region includes pores of a sponge-like structure, and the content of the gamma-alumina is 1 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the total sum of the content of the alpha-alumina and the content of the gamma-alumina, and the coating layer includes any one selected from the group consisting of a silane compound, a zeolite, and a combination thereof.

[0089] (S1) A step of preparing a dope solution containing a polymer solution, a binder, and alpha-alumina and gamma-alumina;

[0090] The polymer solution according to the present invention may include a polymer resin that serves as a base resin and a solvent that dissolves the polymer resin. In some examples, the polymer resin is not particularly limited and may specifically include one or more selected from the group consisting of polysulfone, polyethersulfone, polyvinylidene fluoride, cellulose, polyacrylonitrile, and polyetherimide. In some examples, the solvent may be a solvent that can dissolve the polymer resin and may be appropriately selected depending on the type of the polymer resin. For example, when the polymer resin is polysulfone, the solvent may be dimethylacetamide.

[0091] The binder according to the present invention can increase viscosity or provide binding strength between solid components included in the dope solution. For example, the binder may include at least one of a glycol compound and glycerol, and specifically, polyethylene glycol.

[0092] Alpha-alumina according to the present invention has excellent chemical stability and can be the main material of the support.

[0093] In some embodiments of the present invention, the average particle diameter (D) of the alpha-alumina 50 ) may be 400 to 600 nm, 450 to 550 nm, or 480 to 520 nm, and specifically may be 500 to 520 nm. According to some embodiments of the present invention, when the average particle diameter of the alpha-alumina satisfies the above numerical range, a porosity with high gas permeability can be implemented within a limit in which the mechanical properties of the support are not deteriorated.

[0094] The gamma-alumina according to the present invention can enhance the mechanical properties of a support without significantly reducing the gas permeability of the support. Specifically, the gamma-alumina can fill the gaps between alpha-alumina particles during sintering, thereby increasing the flexural strength of the support.

[0095] In some embodiments of the present invention, the average particle diameter (D) of the gamma-alumina 50 ) may be 10 to 30 nm, 12 to 25 nm, or 15 to 20 nm. According to some embodiments of the present invention, when the average particle diameter of the gamma-alumina satisfies the numerical range, the viscosity of the dope solution is maintained at an appropriate level, so that the spinning and discharging processes can be easily performed.

[0096] In some embodiments of the present invention, the content of the gamma-alumina may be 1 to 5 parts by weight, 1 to 3 parts by weight, or 3 to 5 parts by weight, and most preferably 4 to 5 parts by weight or 5 parts by weight, based on 100 parts by weight of the total sum of the content of the alpha-alumina and the content of the gamma-alumina. According to some embodiments of the present invention, when the content of the gamma-alumina is less than the above numerical range, not only may the mechanical properties of the support, such as the bending strength, not be sufficiently improved, but also the problem of a low water condensation ratio may occur, and when it exceeds the above numerical range, the viscosity of the dope solution may become excessively high, making spinning difficult, thereby causing a problem of difficulty in manufacturing a hollow fiber.

[0097] (S2) A step of manufacturing a hollow fiber by irradiating the above dope solution;

[0098] The dope solution according to the present invention is a solution to be irradiated and can be controlled to a temperature of 20 to 30°C.

[0099] Specifically, the equipment for radiating the above dope solution is not particularly limited, and a triple-tubular radiator nozzle or a double-tubular radiator nozzle commercially available in the relevant technical field may be used.

[0100] In some examples, the spinning temperature can be adjusted to 50 to 60°C, the spinning pressure to 10 to 30 bar, and the air gap distance to 5 to 15 cm. Through the spinning process, hollow fibers can be spun.

[0101] (S3) A step of manufacturing a solidified hollow fiber by immersing the hollow fiber in a non-solvent;

[0102] The hollow fiber according to the present invention can be solidified by a phase transition reaction through material exchange between a solvent and a nonsolvent in a coagulation tank or a water tank. This solidification reaction can be referred to as a nonsolvent-induced phase separation (NIPS) method, which refers to a method in which a uniformly mixed homogeneous solution comes into contact with a nonsolvent, resulting in material exchange between the solvent and the nonsolvent.

[0103] The nonsolvent according to the present invention is a solvent that does not dissolve the solid content contained in the dope solution and can induce the solidification of the hollow fiber. In some examples, the nonsolvent may be appropriately selected depending on the type of dope solution, and specifically may include water at room temperature.

[0104] (S4) A step of drying the solidified hollow fiber and then sintering the dried hollow fiber to manufacture a support;

[0105] The method for manufacturing a moisture condensation membrane according to the present invention may include a drying step to remove moisture contained in the solidified hollow fiber. In some examples, the drying step may include drying at room temperature.

[0106] In some embodiments of the present invention, the step of sintering the dried hollow fiber may include a first step of heating the hollow fiber to 750 to 850°C at a heating rate of 5 to 7°C in an oxygen atmosphere and then maintaining the temperature for 4 to 6 hours; a second step of heating the hollow fiber to 1500 to 1600°C at a heating rate of 5 to 7°C / min and then maintaining the temperature for 7 to 9 hours; and a third step of cooling the hollow fiber to room temperature at a cooling rate of 5 to 7°C / min. According to some embodiments of the present invention, when the sintering temperature heating rate, cooling rate, and sintering time of the first to third steps are all satisfied, a support having both pores of a finger-like structure and pores of a sponge-like structure and having an appropriate level of permeability and mechanical properties of a dehumidified gas can be realized. If at least one of the conditions of the first to third steps is not satisfied, a problem may arise in which a support having an appropriate level of dehumidified gas permeability and mechanical properties cannot be realized.

[0107] (S5) A step of forming a coating layer on at least one surface of the support;

[0108] The method for manufacturing a separation membrane for moisture condensation according to the present invention includes a step of forming a coating layer to impart hydrophobicity to the surface of the support to further increase the efficiency of moisture condensation for gas.

[0109] In some examples, a method for forming a coating layer including the silane compound may include a method of immersing the support in a silane solution in which the silane compound is dissolved in a solvent; or a method of stirring the support and the silane solution using an ultrasonic stirrer, and preferably a method of stirring the support and the silane solution using an ultrasonic stirrer. According to some embodiments of the present invention, a method of stirring the support and the silane solution using an ultrasonic stirrer may exhibit a more excellent effect of imparting hydrophobicity to the surface of the membrane compared to the immersion method. At this time, a solvent for dissolving the silane compound may be appropriately selected depending on the type of the silane compound.

[0110] In some embodiments of the present invention, the stirring method using the ultrasonic stirrer may include a step of stirring for 1 to 3 hours. Specifically, when the stirring method using the ultrasonic stirrer satisfies the above numerical range, the effect of imparting hydrophobicity to the surface of the separation membrane is more effectively expressed, thereby further increasing the efficiency of condensing moisture from the gas.

[0111] In some embodiments of the present invention, when the silane compound is trimethoxysilane, a method of stirring using an ultrasonic stirrer for 2 hours or more is used as a coating method, and hexane is selected as a solvent, so that the hydrophobicity of the membrane surface is further increased, and thus the water vapor condensation rate can be further increased.

[0112] In some embodiments of the present invention, when the silane compound is hexadecyltrimethoxysilane, a method of immersing for 5 hours or more is used as a coating method, and hexane is selected as a solvent, so that the hydrophobicity of the surface of the separation membrane is further increased, and thus the water vapor condensation rate can be further increased.

[0113] In some embodiments of the present invention, a method for manufacturing a separation membrane for moisture condensation may include a step of immersing the support in a zeolite dispersion and then drying it.

[0114] In some embodiments of the present invention, the method may further include a step of immersing a support immersed and dried in the zeolite dispersion in a matured hydrothermal solution to induce secondary growth, thereby manufacturing a preliminary separation membrane; and a step of immersing the preliminary separation membrane in the silane solution and then drying it to manufacture a separation membrane for moisture condensation. At this time, when the secondary growth is completed, a zeolite thin film with a uniform surface can be formed.

[0115] In some embodiments of the present invention, the maturation time of the hydrothermal solution may be at least 1 hour, at least 10 hours, and preferably at least 24 hours at room temperature. According to some embodiments of the present invention, when the maturation time of the hydrothermal solution satisfies the above numerical range, the effect of significantly increasing nitrogen permeability can be achieved.

[0116] In some embodiments of the present invention, the concentration of zeolite may be 1 wt% or less, 0.5 wt% or less, 0.1 wt% or less, 0.05 wt% or less, and preferably 0.04 to 0.05 wt%, based on the total weight of the zeolite dispersion. According to some embodiments of the present invention, when the concentration of the zeolite satisfies the above numerical range, the effect of significantly increasing nitrogen permeability can be achieved.

[0117] In some embodiments of the present invention, the immersion time in the aqueous solution may be 5 minutes or less, 4 minutes or less, 3 minutes or less, 2 minutes or less, and most preferably 1 minute or less. For example, the immersion time in the aqueous solution may be the seed crystal coating time. Preferably, the immersion in the aqueous solution may be performed twice.

[0118] 3. Gas dehumidification method

[0119] According to another aspect of the present invention, a method for dehumidifying a gas using a moisture condensation membrane of some embodiments is provided.

[0120] Figure 2 is a schematic diagram showing a gas dehumidification method according to one embodiment of the present invention.

[0121] Referring to FIG. 2, a method for dehumidifying a gas (200) according to the present invention may include a step of increasing the humidity of a gas coming from various sources through a moisture supply unit (110); a step of supplying the gas with increased humidity to a separation membrane module (130); and a step of obtaining liquid water (131) condensed from the gas with increased humidity through a moisture condensation separation membrane (100) of some embodiments included in the separation membrane module (130). Here, TC is a thermometer for measuring temperature, and THM is a device for controlling the flow of heat and moisture.

[0122] In some examples, the above method of dehumidifying gas is not particularly limited and can be applied to not only dehumidifying air in automobiles, buildings, factories, etc., but also to gas flows generated in industrial sites such as combustion exhaust gases.

[0123] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, this is merely an example, and the scope of the present invention is not limited by the following contents.

[0124] [Manufacturing Preparation Example 1: Manufacturing of a Support Using a Non-Solvent-Induced Phase Separation Process]

[0125] <Manufacturing Preparation Example 1-1: Support manufactured using a dope solution not containing gamma-alumina>

[0126] Preparation steps for dope solution:

[0127] Polysulfone (Mn = 22,000 g / mol, 100 g) was dissolved in dimethylacetamide (400 g) to prepare a 20 wt% polymer solution. Alpha-alumina (D 50=500 nm, 700 g), the above polymer solution (500 g) and polyethylene glycol 400 (binder, 70 g) were mixed and ground in a ball mill at 50°C to prepare a dope solution.

[0128] Step of radiating the above dope solution:

[0129] The above dope solution (50°C) was spun using a triple-tubular spinning nozzle under the spinning conditions described in Table 1 to produce a hollow fiber.

[0130] Step of solidifying the above hollow fiber using a non-solvent induced phase transition separation method:

[0131] The above hollow fiber was immersed in a non-solvent (water) at room temperature contained in a tank for 24 hours to produce a solidified hollow fiber.

[0132] Step of drying and sintering the above solidified hollow fiber:

[0133] The above-mentioned solidified hollow fiber was dried at room temperature until dry. The dried hollow fiber was heated to 800°C at a rate of 5°C / min in an oxygen atmosphere (1 L / min) using a furnace, maintained at that temperature for 5 hours, and then sintered to 1530°C at a rate of 5°C / min for 8 hours. Then, it was cooled to room temperature at a rate of 5°C / min, thereby producing a tubular alpha-alumina hollow fiber support.

[0134] Spinning conditions of the dope solution: Spinning temperature: 50℃, Spinning pressure: 10-30 bar, Air gap distance: 10 cm

[0135] <Manufacturing Preparation Example 1-2: Manufacturing of a support prepared with a dope solution having a gamma-alumina content of 1 wt%>

[0136] In the step of preparing the dope solution of the above Manufacturing Preparation Example 1-1, the content of alpha-alumina was adjusted to 693 g so that the content of gamma-alumina was 1 wt% based on the total sum of the content of gamma-alumina and the content of alpha-alumina of 100 wt% (700 g), and a support was prepared in the same manner as Manufacturing Preparation Example 1-1, except that gamma-alumina (7 g, D50 = 15 nm) was additionally added.

[0137] <Manufacturing Preparation Example 1-3: Manufacturing of a support prepared with a dope solution containing 3 wt% of gamma-alumina>

[0138] A support was manufactured in the same manner as in Manufacturing Preparation Example 1-2, but the content of gamma-alumina was adjusted to 3 wt% (21 g) based on a total sum of 100 wt% of the content of gamma-alumina and the content of alpha-alumina (700 g).

[0139] <Manufacturing Preparation Example 1-4: Preparation of a support prepared with a dope solution containing 5 wt% of gamma-alumina>

[0140] A support was manufactured in the same manner as in Manufacturing Preparation Example 1-2, but the content of gamma-alumina was adjusted to 5 wt% (35 g) based on a total sum of 100 wt% of the content of gamma-alumina and the content of alpha-alumina (700 g).

[0141] [Experimental Example 1: Evaluation of Support Properties]

[0142] Bending strength

[0143] The bending strength of each support according to Manufacturing Preparation Examples 1-1 to 1-4 was measured using a three-point bending tester (H25KS, Hounsfield, England). At this time, the total thickness of the support sample was 400 μm.

[0144] Porosity, average pore diameter and bulk density

[0145] The porosity and average pore diameter of the support according to the above manufacturing preparation examples 1-1 to 1-4 were measured using a mercury porosity analyzer (Pascal 440, Thermo Fisher Scientific).

[0146] In addition, the bulk density of each support according to the above manufacturing preparation examples 1-1 to 1-4 was calculated as the weight for the volume of each support measured by the mercury porosity analyzer.

[0147] Water permeability

[0148] The water permeability was calculated according to the following equation 1. Specifically, the measurement conditions for the water permeability of the support according to the manufacturing preparation examples 1-1 to 1-4 were set as follows: the injection temperature was 90°C, the relative humidity was 80 to 100%, the injection gas was 100 ccm, and the injection pressure was 1.5 bar.

[0149] [Formula 1]

[0150] Water permeability (L / m) 2· h) = {[Volume of condensed water (L)] / [Area of ​​support (m 2 ) / Operating time (h)]}

[0151] Nitrogen permeation rate and nitrogen permeability

[0152] For each support according to the above manufacturing preparation examples 1-1 to 1-4, the nitrogen permeation rate and nitrogen permeability were measured using a flow controller when nitrogen (N2) gas was flowed at a flow rate of 1,000 mL / min at 25°C for 1 hour. At this time, the flow rate of nitrogen gas was controlled at 100 ccm and the pressure was controlled at 1.5 bar.

[0153] Classification gamma-alumina (wt%) a Bending strength (MPa)Porosity (%)Average pore diameter (nm) b) Bulk density (g / cm) 3 )Water permeability (L / m) 2 h) Nitrogen permeation rate [mol / (m 2·s·Pa)]N2 Permeability (GPU) Manufacturing Preparation Example 1-1 (N0) 078.5651.73416.051.762828664.27E-05127642 Manufacturing Preparation Example 1-2 (N1) 197.4349.42404.861.845319493.45E-05103177 Manufacturing Preparation Example 1-3 (N3) 3101.6148.69390.801.862617573.23E-0594851 Manufacturing Preparation Example 1-4 (N5) 5114.7248.57351.671.88049552.97E-0588969a) The content of gamma-alumina is equal to the content of alpha-alumina and The weight % is set based on the total sum of 100 weight % of the content of gamma-alumina. b) The average pore diameter is the average of the pores distributed throughout the support.

[0154] Referring to Table 2 above, it was confirmed that as the content of gamma-alumina increases, the bending strength increases as long as the nitrogen permeability is not significantly reduced. However, when Manufacturing Preparation Example 1-5 with a gamma-alumina content of 7 wt% was additionally attempted, it was confirmed that the viscosity of the dope solution was too high and spinning was impossible. Through this, it was confirmed that the content of gamma-alumina that can improve the bending strength of the support within a range where the appropriate viscosity of the dope solution for spinning is satisfied and the nitrogen permeability of the support is not significantly reduced is 1 to 5 wt%, 3 to 5 wt%, and most preferably 5 wt%, based on 100 wt% of the total sum of the content of alpha-alumina and the content of gamma-alumina.

[0155] Figure 3 is a SEM (Scanning Electron Microscope) photograph of the bending strength of the support according to Manufacturing Preparation Examples 1-1 to 1-4 and the support according to Manufacturing Preparation Examples 1-2 and 1-4.

[0156] Referring to Fig. 3, it was confirmed that the higher the content of gamma-alumina, the higher the bending strength of the support according to Manufacturing Preparation Examples 1-1 to 1-4.

[0157] In addition, it was confirmed that the supports of Manufacturing Preparation Examples 1-2 and 1-4 included pores of a finger-like structure and a sponge-like structure.

[0158] [Manufacturing Example 1: Manufacturing of a Membrane]

[0159] <Comparative Example 1: Support according to Manufacturing Preparation Example 1-4>

[0160] A support was prepared according to the above manufacturing preparation example 1-4.

[0161] <Example 1: Separator including a silane coating layer manufactured by immersing in a TMS solution>

[0162] A first trimethoxysilane solution having a trimethoxysilane concentration of 0.01 M was prepared by dissolving trimethoxysilane in hexane.

[0163] The support according to Preparation Example 1-4 was immersed in the first trimethoxysilane solution for 2 hours (Example 1-1) and 5 hours (Example 1-2), respectively. The immersed resultant was taken out and dried in an oven at 50°C for 60 minutes to produce a separation membrane.

[0164] <Example 2: Different from Example 1, but with a different solvent>

[0165] A second trimethoxysilane solution having a trimethoxysilane concentration of 0.01 M was prepared by dissolving trimethoxysilane in ethanol.

[0166] A membrane was manufactured in the same manner as in Example 1, but the second trimethoxysilane solution was used instead of the first trimethoxysilane solution. The support was immersed in the second trimethoxysilane solution for 2 hours (Example 2-1) and 5 hours (Example 2-2), respectively.

[0167] <Example 3: Separator including a silane coating layer manufactured by immersing in an HDTMS solution>

[0168] Hexadecyltrimethoxysilane was dissolved in hexane to prepare a first hexadecyltrimethoxysilane solution having a concentration of 0.01 M.

[0169] A separation membrane was manufactured in the same manner as in Example 1, but the support was immersed in the first hexadecyltrimethoxysilane solution instead of the first trimethoxysilane solution for 2 hours (Example 3-1) and 5 hours (Example 3-2), respectively.

[0170] <Example 4: Different from Example 3, but with a different solvent>

[0171] A second hexadecyltrimethoxysilane solution having a hexadecyltrimethoxysilane concentration of 0.01 M was prepared by dissolving hexadecyltrimethoxysilane in ethanol.

[0172] A separation membrane was manufactured in the same manner as in Example 1, but the support was immersed in the second hexadecyltrimethoxysilane solution instead of the first trimethoxysilane solution for 2 hours (Example 4-1) and 5 hours (Example 4-2), respectively.

[0173] <Example 5: Separator including a silane coating layer manufactured by an ultrasonic stirring method>

[0174] Using an ultrasonicator, the support according to Manufacturing Preparation Example 1-4 and the first and second trimethoxysilane solutions and the first and second hexadecyltrimethoxysilane solutions were stirred for 2 hours, and then dried at 50°C for 60 minutes to manufacture membranes of Examples 5-1 and 5-2 (first and second trimethoxysilane solutions) and Examples 5-3 and 5-4 (first and second hexadecyltrimethoxysilane solutions), respectively.

[0175] [Experimental Example 2: Measurement of the contact angle of water on the surface of the membrane]

[0176] In order to evaluate the hydrophobicity of the surface of the membrane according to Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, and 5-1 to 5-4, 1 μl of a water droplet was dropped onto the surface of the membrane, and the contact angle of the water droplet was measured using a contact angle meter at room temperature and 50% RH. The higher the contact angle of the water droplet, the better the surface of the membrane was modified to be hydrophobic.

[0177] Figure 4 shows the contact angle results of water droplets on the surface of the separation membrane according to Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, and 5-1 to 5-4.

[0178] Referring to Figure 4, it was confirmed that the contact angle on the surface of the membrane greatly changed depending on the solvent dissolving silane and the coating conditions.

[0179] From the perspective of hydrophobicity of the membrane surface according to the immersion time, it can be inferred that the hydrophobicity of the membrane surface increases as the immersion time increases, regardless of the solvent.

[0180] From the perspective of hydrophobicity of the membrane surface according to the coating method, it can be inferred that the method of modifying the membrane surface to be hydrophobic using an ultrasonic disperser, regardless of the solvent, provides more hydrophobicity to the membrane surface compared to the immersion method.

[0181] From the perspective of hydrophobicity of the membrane surface depending on the type of solvent, it was confirmed that the solvent capable of imparting hydrophobicity to the membrane surface can be determined depending on the type of silane. For example, in the case of hexadecyltrimethoxysilane, in the case of the membrane of Example 3-2, which used hexane as the solvent, the immersion method as the coating method, and the immersion time was adjusted to 5 hours, the contact angle of the water droplet on the membrane surface was the highest, confirming that the hydrophobicity of the membrane surface was more strongly imparted.

[0182] [Experimental Example 3: Evaluation of Nitrogen Permeability of Membranes]

[0183] Figure 5 is a graph showing nitrogen permeability according to water vapor condensation time of the separation membranes according to Comparative Example 1 and Example 3-2. Specifically, the nitrogen permeability of each separation membrane was measured when nitrogen gas was flowed for 1 hour at a flow rate of 500 ccm and an injection pressure of 2 bar at 70°C and 100% relative humidity.

[0184] Referring to Fig. 5, the membrane of Example 3-2 exhibited higher water permeability than the membrane of Comparative Example 1, while at the same time exhibiting a nitrogen permeability that did not change significantly even after the condensation time of water vapor had elapsed. Through this, it can be inferred that the nitrogen permeability was increased by effectively preventing moisture from penetrating into the pores of the membrane by arranging a silane coating layer on the surface of the membrane of Example 3-2.

[0185] On the other hand, in the case of the separation membrane of Comparative Example 1, it was confirmed that most of the pores included in the separation membrane were blocked by moisture, resulting in a significantly low nitrogen permeability.

[0186] [Experimental Example 4: Evaluation of the Moisture Removal Rate of the Membrane]

[0187] Figure 6a is a graph of the moisture removal rate according to the water vapor condensation time of the separation membrane according to Comparative Example 1 and Example 3-2. Specifically, the moisture removal rate of each separation membrane was calculated when an injection gas containing water vapor was flowed for 1 hour at an injection temperature of 70°C and a relative humidity of 100%, a flow rate of 100 ccm, and an injection pressure of 1 bar. Here, the moisture removal rate of the separation membrane was calculated based on the following Equation 2.

[0188] [Formula 2]

[0189]

[0190] In the above equation 2, M fis the mass (g) of water vapor contained in the feed gas, and Mp is the mass (g) of water vapor contained in the permeating gas.

[0191] Figure 6b is a photograph showing the contact angle of a water droplet on the surface of a separator according to Comparative Example 1. Figure 6c is a photograph showing the contact angle of a water droplet on the surface of a separator according to Example 3-2. In this case, the contact angle of the water droplet was measured using the same method as in Experimental Example 2.

[0192] Referring to Figures 6a to 6c, it was confirmed that the separation membrane of Example 3-2 exhibited a high moisture removal rate even though the water condensation time increased compared to the separation membrane of Comparative Example 1.

[0193] [Manufacturing Preparation Example 2: Synthesis of Silicalite-1 Particles]

[0194] TEOS(Tetraethyl orthosilicate) 25 mol (SiO 2, AS-30), a mixture of 9 mol of TPABr (Tetrapropylammonium bromide), 0.16 mol of NaOH, and 495 mol of H2O was placed in a hydrothermal reactor and the synthesis reaction was performed at 180°C for 48 hours. After synthesis, the solid particles precipitated under the hydrothermal reactor were washed with distilled water until the pH became 7, and then dried at 50°C for more than 24 hours. In order to remove TPABr contained in the dried result, heat treatment was performed at 550°C for 20 hours, and the average particle diameter (D) was finally determined. 50 ) synthesized silicalite-1 particles with a size of 100 nm.

[0195] [Manufacturing Example 2: Manufacturing of a membrane including a zeolite coating layer]

[0196] <Example 6: Preparation of a separator including a silicalite-1 coating layer>

[0197] Steps for preparing the silicalite-1 dispersion of the above manufacturing preparation example 2:

[0198] The silicalite-1 particles of the above manufacturing preparation example 2 were dispersed in an ethanol aqueous solution (99% (v / v)) to prepare a silicalite-1 dispersion having a silicalite-1 particle concentration of about 0.05 wt%.

[0199] Step of immersing the support of the above manufacturing preparation example 1-4 in the above silicalite-1 dispersion:

[0200] The support of Preparation Example 1-4, with the holes at both ends closed, was immersed in the silicalite-1 dispersion for a first time for 2 minutes, a second time for 2 minutes, and a third time for 2 minutes. The support that was immersed for the third time was taken out and dried at 50°C for 24 hours to manufacture the separation membrane of Example 6.

[0201] <Example 7: Preparation of a separator comprising silicalite-1 and a silane coating layer>

[0202] Maturation stages of the aqueous solution:

[0203] Colloidal silica (SiO 2, A mixture (aqueous solution) of AS-30, TPABr (Tetrapropylammonium bromide), NaOH, and H2O in a molar ratio of 1:0.005:0.05:100 was aged at room temperature for 24 hours.

[0204] Secondary growth stage:

[0205] The separation membrane of Example 6 was immersed in the aged mixture (aged hydrothermal solution) twice for 0.5 minutes each for a total time of 1 minute, and then the secondary growth of silicalite-1 was induced for 60 minutes in a hydrothermal reactor heated to 160°C (heating rate: 1°C / min), thereby manufacturing a separation membrane including a secondary-grown zeolite film.

[0206] Steps for immersing in silane solution:

[0207] A separation membrane including the above-mentioned secondarily grown zeolite thin film (average thickness: about 10 ㎛, average spacing between crystal grains: about 200 nm) was immersed in a silane solution (silane concentration = 0.1 M) containing hexadecyltrimethoxysilane and n-butanol for 5 hours, then taken out and dried at 50°C for 24 hours to manufacture a separation membrane of Example 7.

[0208] <Example 8: Unlike Example 7, the maturation stage time of the aqueous solution and the concentration of silicalite-1 particles are different>

[0209] A separation membrane was manufactured in the same manner as in Example 7, but the maturation time of the aqueous solution was changed from 24 hours to 1 hour, and the concentration of silicalite-1 particles was changed from 0.05 wt% to 0.1 wt%. At this time, as a result of analysis using SEM images, the average thickness of the zeolite thin film in Example 8 was approximately 1 ㎛, and the average spacing between crystal grains was approximately 10 nm.

[0210] <Example 9: Unlike Example 7, when the conditions for coating the secondary growth seed crystal are different>

[0211] A membrane was manufactured in the same manner as in Example 7, but the immersion time in the aged mixture was changed from 1 minute to 2 minutes (Example 9-1), which is the total time for immersion twice for 1 minute each, 3 minutes (Example 9-2), which is the total time for immersion twice for 1.5 minutes each, and 4 minutes (Example 9-3), which is the total time for immersion twice for 2 minutes each.

[0212] [Experimental Example 5: Evaluation of Moisture Removal Rate and Nitrogen Permeability of Membranes According to Feed Pressure]

[0213] Figure 7a is a graph showing the moisture removal rate according to the feed pressure of the separation membranes of Comparative Example 1, Example 3-1, and Example 8. Except for adjusting the feed pressure, the moisture removal rate of the separation membranes was analyzed using the same method as Experimental Example 4.

[0214] Referring to Fig. 7a, the membrane of Example 8 exhibited a significantly higher moisture removal rate than the membranes of Comparative Example 1 and Example 3-1 in all feed pressure ranges. This confirmed that the inclusion of the silicalite-1 coating layer and the silane coating layer in the coating layer further enhanced the superhydrophobic properties on the surface of the membrane, thereby significantly increasing the moisture removal rate of the membrane.

[0215] Figure 7b is a graph showing the nitrogen permeability according to the feed pressure of the separation membranes of Comparative Example 1, Example 3-1, and Example 8. Except for adjusting the feed pressure, the nitrogen permeability of the separation membranes was analyzed using the same method as Experimental Example 3.

[0216] Referring to Fig. 7b, it was confirmed that the separation membrane of Example 8 exhibited high nitrogen permeability under a feed gas pressure condition of 0.3 bar or more compared to Comparative Example 1.

[0217] When the above experimental results are comprehensively considered, the separation membrane of Example 8 showed a slightly lower nitrogen permeability compared to the separation membrane of Example 3-1 (silane coating layer), but the introduction of a coating layer including silicalite particles coated by secondary growth showed a significantly higher moisture removal rate.

[0218] [Experimental Example 6: Evaluation of Nitrogen Permeability and Moisture Removal Rate According to Seed Crystal Coating Conditions]

[0219] Figure 8 is a graph showing the nitrogen permeability according to the feed pressure of the separation membrane according to Examples 7 and 9-1 to 9-3. The nitrogen permeability was evaluated in the same manner as in Experimental Example 3, except that the feed pressure was adjusted.

[0220] Referring to Figure 8, it was confirmed that Example 7, which is a membrane coated with a seed crystal for 1 minute, exhibited a higher nitrogen permeability compared to Examples 9-1 to 9-3, which were coated with a seed crystal for 2 minutes or more.

[0221] Figure 9 is a graph showing the moisture removal rate according to the feed pressure of the separation membrane according to Examples 7 and 9-1 to 9-3. Except for adjusting the feed pressure, the moisture removal rate of the separation membrane was evaluated using the same method as in Experimental Example 4.

[0222] Referring to Figure 9, Example 7, which is a membrane coated with a seed crystal for 1 minute, exhibited a moisture removal rate of about 70%.

[0223] [Experimental Example 7: Evaluation of Nitrogen Permeability and Moisture Removal Rate According to the Maturation Time of the Hydrothermal Solution]

[0224] The nitrogen permeability and moisture removal rate of the membrane according to Examples 7 and 8 were measured using the same methods as those described in Experimental Examples 3 and 4 above. At this time, the feed pressure was controlled at 2 bar.

[0225] Distinction Silicalite-1 particle concentration (wt%) Water column solution maturation time N2 permeability (GPU) Moisture removal rate (%) Example 70.05 wt% 24 hours 15,000 GPU 70% Example 80.1 wt% 1 hour 200 GPU 80%

[0226] Referring to Table 3 above, Example 7, in which the maturation time of the aqueous solution was adjusted to 24 hours or more and the concentration of silicalite-1 particles was adjusted to 0.05 wt%, showed a slightly lower moisture removal rate compared to Example 8, but a significantly higher nitrogen permeability. Through this, it was confirmed that when the maturation time of the aqueous solution was adjusted to more than 1 hour, more preferably, more than 24 hours, the nitrogen permeability was significantly increased.

[0227] [Experimental Example 8: Evaluation of Moisture Condensation Performance According to Secondary Growth Conditions]

[0228] Figure 10 shows SEM images of the membranes according to Examples 7 and 9-1 to 9-3 and the contact angle results for water droplets. The contact angle evaluation results were performed under the same analysis conditions as in Experimental Example 2.

[0229] Referring to Fig. 10, Example 7 was immersed and coated twice for 0.5 minutes each for a total of 1 minute compared to Examples 9-1 to 9-3, thereby widening the coating gap between the seed crystal particles and confirming that the gap between the crystal grains of the synthesized separation membrane was controlled to be wide.

[0230] The features described in the above-described embodiment may be combined with other embodiments unless explicitly stated otherwise. Furthermore, while the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art utilizing the basic concepts of the present invention defined in the following claims also fall within the scope of the present invention.

[0231] [Explanation of symbols]

[0232] 10: Support

[0233] 10a: Area 1

[0234] 10b: Area 2

[0235] 20: Coating layer

[0236] 100: Membrane for moisture condensation

Claims

1. A support comprising a first region and a second region on the first region; and A coating layer on the above support; The above first region includes pores of a ground structure (finger-like structure), The second region includes pores of a sponge-like structure, The above coating layer is, Comprising any one selected from the group consisting of silane compounds, zeolites and combinations thereof; Membrane for moisture condensation.

2. In paragraph 1, The second region is positioned between the first region and the coating layer. Membrane for moisture condensation.

3. In paragraph 1, The average diameter of the pores included in the first region is 150 ㎛ or more and 200 ㎛ or less in the long axis and 10 ㎛ or more and 30 ㎛ or less in the short axis. The average diameter of the pores included in the above second region is 0.1 ㎛ or more and 1.5 ㎛ or less. Membrane for moisture condensation.

4. In paragraph 1, The above support comprises a ceramic support. Membrane for moisture condensation.

5. In paragraph 1, The above silane compound is, Trimethoxy(propyl)silane, Hexadecyltrimethoxysilane, Isobutyl(trimethoxy)silane, Trimethoxy(octyl)silane, Trimethoxy(octadecyl)silane, [3-(Diethylamino)propyl]trimethoxysilane, (N,N-Dimethylaminopropyl)trimethoxysilane, Trimethoxy(3,3,3-trifluoropropyl)silane, Trimethoxy(2-phenylethyl)silane, Trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, n-Propyltriethoxysilane, Triethoxy(isobutyl)silane, Triethoxy(pentyl)silane, Triethoxy(hexyl)silane, Triethoxy(octyl)silane, N-Octadecyltriethoxysilane, Cyclopentyltriethoxysilane Containing at least one selected from the group consisting of (Cyclopentyltriethoxysilane), and (Triethoxysilyl)cyclohexane. Membrane for moisture condensation.

6. In paragraph 1, The above zeolite comprises a hydrophobic zeolite having a Si / Al ratio of 1,000 or more. Membrane for moisture condensation.

7. In paragraph 1, The above coating layer: comprising a first layer and a second layer on the first layer, The first layer is disposed between the second region and the second layer, The above first layer comprises a zeolite thin film in which the zeolite is secondarily grown, The second layer comprises the silane compound, Membrane for moisture condensation.

8. (S1) A step of preparing a dope solution containing a polymer solution, a binder, alpha-alumina and gamma-alumina; (S2) A step of manufacturing a hollow fiber by radiating the above dope solution; (S3) A step of manufacturing a solidified hollow fiber by immersing the hollow fiber in a non-solvent; (S4) a step of drying the solidified hollow fiber and then sintering the dried hollow fiber to manufacture a support; and (S5) a step of forming a coating layer on at least one surface of the support; including; The above support is, comprising a first region and a second region on the first region, The above first region includes pores of a ground structure (finger-like structure), The second region includes pores of a sponge-like structure, The content of the gamma-alumina is 1 part by weight or more and 5 parts by weight or less for 100 parts by weight of the total sum of the content of the alpha-alumina and the content of the gamma-alumina, The above coating layer is, Comprising any one selected from the group consisting of silane compounds, zeolites and combinations thereof; A method for manufacturing a separation membrane for moisture condensation.

9. In paragraph 8, The above step (S5) is: A step of immersing the support in a zeolite dispersion and then drying it; A step of manufacturing a preliminary separation membrane by immersing the above-mentioned immersed and dried support in a water solution, and A step of manufacturing a separation membrane for moisture condensation by immersing the preliminary separation membrane in a silane solution and then drying it, A method for manufacturing a separation membrane for moisture condensation.

10. A method for dehumidifying gas using a moisture condensation membrane according to Article 1.

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