KR102603906B1 - Gas separation membrane, gas separation membrane module comprising the same and preparation method for the same - Google Patents

Abstract

This specification provides a gas separation membrane, a gas separation membrane module including the same, and a method for manufacturing the same.

Description

Gas separation membrane, gas separation membrane module including the same, and manufacturing method thereof {GAS SEPARATION MEMBRANE, GAS SEPARATION MEMBRANE MODULE COMPRISING THE SAME AND PREPARATION METHOD FOR THE SAME}

This application claims the benefit of the filing date of Korean Patent Application No. 10-2018-0051111 filed with the Korea Intellectual Property Office on May 3, 2018, the entire contents of which are incorporated into this specification.

In addition, this application claims the benefit of the filing date of Korean Patent Application No. 10-2018-0082865 filed with the Korea Intellectual Property Office on July 17, 2018, the entire contents of which are incorporated into this specification.

This specification relates to a gas separation membrane, a gas separation membrane module including the same, and a method of manufacturing the same.

The gas separation membrane is composed of a porous layer and an active layer, and is a membrane that selectively separates gas from the mixed gas using the pore size and structural characteristics of the active layer. Therefore, gas permeability and selectivity are used as important indicators of membrane performance, and these performances are greatly influenced by the polymer material that makes up the active layer.

Therefore, there is a need to develop a method to increase the permeability and selectivity of gas separation membranes.

Korean Patent Publication No. 10-2013-0137238

This specification provides a gas separation membrane that selectively separates helium, a gas separation membrane module including the same, and a method of manufacturing the same.

An exemplary embodiment of the present specification includes a porous layer; and a gas separation membrane including an active layer, wherein the active layer includes polyamide, and the polyamide is an aromatic polyamide, wherein the active layer includes pores, and the average pore radius of the pores is 0.239 nm to 0.45 nm. Provides a phosphorus gas separation membrane.

An exemplary embodiment of the present specification includes a porous layer; and an active layer, wherein the active layer is formed by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound, the active layer includes pores, and the average pore radius of the pores is A gas separation membrane of 0.239 nm to 0.45 nm is provided.

An exemplary embodiment of the present specification includes a porous layer; and a gas separation membrane including an active layer, wherein the active layer includes pores, the average pore radius of the pores is 0.239 nm to 0.45 nm, the helium permeability of the gas separation membrane is 40 to 400 GPU, and the gas separation membrane has a helium permeability of 40 to 400 GPU. A gas separation membrane is provided in which the selectivity for helium is 4 to 55, and the average pore radius is measured by positron annihilation lifetime spectroscopy (PALS).

An exemplary embodiment of the present specification provides a gas separation membrane module including the gas separation membrane.

Another exemplary embodiment of the present specification includes forming a second porous support by applying a hydrophilic polymer solution on a first porous support; and forming an active layer on the second porous support by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound, wherein the active layer includes pores. and provides a method of manufacturing a gas separation membrane in which the average pore radius of the pores is 0.239 nm to 0.45 nm.

Helium gas can be selectively separated from a gas mixture using a gas separation membrane according to an exemplary embodiment of the present specification. That is, the present invention can provide a gas separation membrane with high helium permeability and selectivity.

Figure 1 shows a gas separation membrane according to an exemplary embodiment of the present specification.
Figure 2 is a scanning electron microscope (SEM) photograph of the gas separation membrane according to Example 2.

Hereinafter, this specification will be described in more detail.

In this specification, when a member is said to be located “on” another member, this includes not only the case where a member is in contact with another member, but also the case where another member exists between the two members.

In this specification, when a part "includes" a certain component, this does not mean that other components are excluded, but may further include other components, unless specifically stated to the contrary.

In one embodiment of the present specification, means a moiety that is bonded to another substituent or binding portion.

An exemplary embodiment of the present specification includes a porous layer; and a gas separation membrane including an active layer, wherein the active layer includes polyamide, wherein the polyamide is an aromatic polyamide, wherein the active layer includes pores, and the average pore radius of the pores is 0.239 nm to 0.45 nm. Provides a phosphorus gas separation membrane.

Additionally, the porous layer; and a gas separation membrane including an active layer, wherein the active layer includes pores, the average pore radius of the pores is 0.239 nm to 0.45 nm, the helium permeability of the gas separation membrane is 40 to 400 GPU, and the gas separation membrane has a helium permeability of 40 to 400 GPU. A gas separation membrane is provided in which the selectivity for helium is 4 to 55, and the average pore radius is measured by positron annihilation lifetime spectroscopy (PALS).

The permeability refers to the mass transfer rate, and the permeability of helium is measured by a bubble flow meter at 25 to 60°C and 14 to 600 psi (0.096 to 4.14 MPa) under standard temperature and pressure (STP) conditions. It can be measured with a flow meter.

In one embodiment of the present specification, the permeability of helium and selectivity of helium based on carbon dioxide can be measured at a temperature of 25 to 60°C and a pressure of 14 to 600 psi when using a single gas. The single gas means 100 vol% helium or 100 vol% carbon dioxide.

Additionally, the permeability of helium and selectivity of helium based on carbon dioxide can be measured at a temperature of 25 to 60°C and a pressure of 14 to 600 psi when using a mixed gas. The mixed gas means containing 0.001 to 10 vol% of helium, 0.001 to 40 vol% of carbon dioxide, 1 to 45 vol% of nitrogen, and 5% to 98 vol% of methane.

In one embodiment of the present specification, the helium permeability of the gas separation membrane is 40 to 400 GPU. Preferably, the helium transmittance may be 100 to 360 GPU. More preferably, the helium transmittance may be 200 to 360 GPU. Additionally, the helium permeability may be 235 to 356 GPU. If the selectivity range of helium relative to carbon dioxide is simultaneously satisfied along with the permeability range of helium, the cost of the gas separation process can be reduced. The GPU is a Gas Permeation Unit, meaning 10 ^-6 cm ³ (STP)/cm ² ·s ·cmHg.

The helium permeability may increase as the average pore radius of the active layer increases.

The selectivity of helium based on carbon dioxide refers to the ratio of the permeation speed of helium measured based on carbon dioxide. Specifically, the selectivity of helium based on carbon dioxide is the helium permeability measured at 25 to 60°C and 14 to 600 psi, which is the standard temperature and pressure (STP) condition, divided by the permeability of carbon dioxide. It refers to

In an exemplary embodiment of the present specification, the selectivity of helium based on carbon dioxide of the gas separation membrane is 4 to 55. Preferably, the selectivity of helium based on carbon dioxide may be 5 to 30. More preferably, the selectivity of helium based on carbon dioxide may be 5 to 10. According to one example, the selectivity of helium based on carbon dioxide may be 5.4 to 6.5. In addition, when the selectivity range of helium and the permeability range of helium are simultaneously satisfied based on the carbon dioxide, the cost of the gas separation process can be reduced.

The voids may include defects. The size of the pore radius of the defect may be 0.33 nm or more. Specifically, the size of the pore radius of the defect may be 0.33 nm to 0.45 nm.

The defect refers to a defect produced by heterogeneous interfacial polymerization due to heterogeneous coating of an aqueous solution and an organic solution when manufacturing a gas separation membrane according to the present specification.

The size of the pore radius of the defect can be measured by positron annihilation lifetime spectroscopy (PALS), and the positron annihilation time spectroscopy can be calculated using a formula to be described later.

Under the assumption that the defect does not exist, the selectivity of helium relative to carbon dioxide may increase as the average pore radius of the active layer decreases. However, when there is a defect larger than a certain pore size, both helium and carbon dioxide permeate through the defect, so the selectivity for helium decreases.

The case where a defect of a certain pore size or more exists means that the defect includes a defect whose pore radius size is 0.33 nm or more, as described above.

The gas separation membrane according to an exemplary embodiment of the present specification may have different permeability and selectivity for a specific gas depending on the size of the free volume of the active layer. The free volume of the active layer can be adjusted by the size of the average pore radius of the active layer.

The size of the average pore radius of the active layer includes the content of the amine compound contained in the aqueous solution containing the amine compound used to form the active layer, the content of the acyl halide contained in the organic solution containing the acyl halide compound, or the amine compound. It can be adjusted depending on the type and content of the surfactant contained in the aqueous solution or the organic solution containing the acyl halide, or the type and content of the salt contained in the aqueous solution containing the amine compound.

In a gas separation membrane, the greater the gas permeability and selectivity at the same time, the better. However, for most gas separation membrane materials, permeability and selectivity have an inverse correlation.

However, the gas separation membrane according to an exemplary embodiment of the present specification can improve the inverse correlation between permeability and selectivity. That is, the gas separation membrane according to an exemplary embodiment of the present specification can greatly increase the selectivity of helium relative to carbon dioxide while maintaining relatively high helium permeability.

In the case of the existing helium recovery market, helium is recovered using expensive cryogenic distillation from limited natural gas and nuclear power plants, and helium recovery methods using gas separation membranes are limited.

However, by using the gas separation membrane according to an exemplary embodiment of the present specification, helium can be selectively separated from the gas mixture at a relatively low cost.

Being able to selectively separate helium means that the selectivity of helium is high based on the permeability of helium and carbon dioxide.

In one embodiment of the present specification, the aromatic polyamide includes a structure represented by the following formula (A).

[Formula A]

In Formula A, Ar1 is a substituted or unsubstituted arylene group.

In one embodiment of the present specification, Ar1 is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.

In one embodiment of the present specification, Ar1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms.

In one embodiment of the present specification, Ar1 is a substituted or unsubstituted arylene group having 6 to 12 carbon atoms.

In one embodiment of the present specification, Ar1 is a substituted or unsubstituted phenylene group.

In one embodiment of the present specification, Ar1 is hydrogen, a substituted or unsubstituted alkyl group, -SOOH, or -COOH, and a phenylene group substituted or unsubstituted.

In one embodiment of the present specification, Ar1 is a phenylene group unsubstituted or substituted with hydrogen, a methyl group, -SOOH, or -COOH.

In one embodiment of the present specification, Ar1 is a phenylene group substituted with hydrogen, a methyl group, -SOOH, or -COOH.

In one embodiment of the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. The aryl group may be a monocyclic aryl group, such as a phenyl group, biphenyl group, or terphenyl group, but is not limited thereto. The polycyclic aryl group may include a naphthyl group, anthracenyl group, indenyl group, phenanthrenyl group, pyrenyl group, perylenyl group, triphenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto. Preferably, the aryl group is a phenyl group.

In the present specification, an arylene group refers to an aryl group having two bonding positions, that is, a bivalent group. The description of the aryl group described above can be applied, except that each of these is a divalent group.

In one embodiment of the present specification, the aromatic polyamide includes a structure represented by the following formula (1).

[Formula 1]

In Formula 1, R1 is hydrogen; Substituted or unsubstituted alkyl group; -SOOH; or -COOH, r1 is an integer from 0 to 4, and when r1 is 2 or more, R1 are the same or different from each other.

In one embodiment of the present specification, R1 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R1 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R1 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R1 is hydrogen; Substituted or unsubstituted methyl group; -SOOH; or -COOH.

In one embodiment of the present specification, R1 is hydrogen; methyl group; -SOOH; or -COOH.

In one embodiment of the present specification, the aromatic polyamide may further include a structure represented by one or both of the following formulas B-1 and B-2.

[Formula B-1]

[Formula B-2]

In Formulas B-1 and B-2, Ra and Rb are the same or different from each other and are each independently hydrogen; -COOH; Or, it is an acyl halide group, and ra is an integer of 0 to 3. When ra is 2 or more, Ra is the same or different from each other, rb is an integer of 0 to 4, and when rb is 2 or more, Rb is the same or different.

In Formulas B-1 and B-2, Ra and Rb are the same or different from each other and are each independently hydrogen; -COOH; or -COCl, ra is an integer from 0 to 3, and when ra is 2 or more, Ra is the same or different from each other, rb is an integer from 0 to 4, and when rb is 2 or more, Rb is the same or different from each other.

In one embodiment of the present specification, Ra is hydrogen.

In one embodiment of the present specification, Rb is hydrogen; COOH; or -COCl.

In one embodiment of the present specification, the aromatic polyamide has a structure represented by Formula 1; and structures represented by either or both of the structures represented by Formula B-1 and Formula B-2.

In the present specification, the acyl halide group may be represented by R ₁₀₀ COX, where R ₁₀₀ may be a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, but is not limited thereto, and X represents a halogen group. .

In this specification, examples of halogen groups include fluorine, chlorine, bromine, or iodine.

In one embodiment of the present specification, the aromatic polyamide is composed of an amine group (-NH ₂ ) of a compound represented by the following formula 1-1 and an acyl halide group (specifically, an acyl chloride group, -COCl) of an acyl halide compound. ) contains an amide bond (-CONH-) formed by polymerization.

[Formula 1-1]

In Formula 1-1, R14 is hydrogen; Substituted or unsubstituted alkyl group; -SOOH; or -COOH, r14 is an integer of 0 to 5, and when r14 is 2 or more, R14 is the same or different from each other, and m is an integer of 1 or 2.

In one embodiment of the present specification, m+r14 is an integer from 1 to 6.

In one embodiment of the present specification, R14 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R14 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R14 is hydrogen; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; -SOOH; or -COOH.

In one embodiment of the present specification, R14 is hydrogen; Substituted or unsubstituted methyl group; -SOOH; or -COOH.

In one embodiment of the present specification, R14 is hydrogen; methyl group; -SOOH; or -COOH.

In an exemplary embodiment of the present specification, r14 in Formula 1-1 is 0 and m is 2.

In the present specification, the alkyl group may be straight chain or branched, and according to one embodiment, the alkyl group has 1 to 30 carbon atoms. According to another embodiment, the carbon number of the alkyl group is 1 to 20. According to another embodiment, the carbon number of the alkyl group is 1 to 10. Specific examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-oxyl group. There is a til group, etc., but it is not limited to these.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 30 carbon atoms, and is particularly preferably a cyclopentyl group or a cyclohexyl group, but is not limited to these.

In one embodiment of the present specification, the aromatic polyamide may be a fully aromatic polyamide. The fully aromatic polyamide means that both the amine compound and the acyl halide compound used to polymerize the fully aromatic polyamide are aromatic.

In one embodiment of the present specification, the amine compound included in the aqueous solution containing the amine compound may be an aromatic amine compound.

In one embodiment of the present specification, the amine compound may include a compound represented by Formula 1-1. Compounds represented by Formula 1-1 include, for example, m-phenylenediamine, p-phenylenediamine, 2,3-diaminotoluene, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 3,4-diaminotoluene, m-toluidine, p-toluidine, or o-toluidine may be used, but are not necessarily limited thereto.

In one embodiment of the present specification, the acyl halide compound included in the organic solution containing the acyl halide compound may be an aromatic acyl halide compound.

In an exemplary embodiment of the present specification, the acyl halide compound contained in the organic solution containing the acyl halide compound is not particularly limited as long as it can be used in the polymerization of polyamide, but may include two or three carboxylic acid halides. It may be an aromatic compound having

For example, the acyl halide compound may be one or a mixture of two or more selected from the group consisting of trimesoyl chloride, isophthaloyl chloride, and terephthaloyl chloride, and trimesoyl chloride is preferably used. You can.

In one embodiment of the present specification, the aromatic polyamide may include a structure represented by the following formula C.

[Formula C]

In the above formula C, Ar2 and Ar3 are the same or different from each other and each independently represents a substituted or unsubstituted arylene group.

In one embodiment of the present specification, Ar2 and Ar3 are the same as or different from each other, and each independently represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.

In an exemplary embodiment of the present specification, Ar2 and Ar3 are the same or different from each other, and each independently represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms.

In an exemplary embodiment of the present specification, Ar2 and Ar3 are the same as or different from each other, and each independently represents a substituted or unsubstituted arylene group having 6 to 12 carbon atoms.

In an exemplary embodiment of the present specification, Ar2 and Ar3 are the same or different from each other and are each independently a substituted or unsubstituted phenylene group.

In one embodiment of the present specification, the aromatic polyamide may include a structure represented by any one or two or more of the following formulas D-1 to D-3, but is not limited thereto.

[Formula D-1]

[Formula D-2]

[Formula D-3]

In the above formulas D-1 to D-3,

R21 to R23 are the same or different from each other, and are each independently hydrogen; -COOH; or -COCl,

R' is a hydroxy group (-OH); or chlorine (-Cl),

R11 to R13 are the same as or different from each other, and are each independently hydrogen; Substituted or unsubstituted alkyl group; -SOOH; or -COOH,

r21 to r23 and r11 to r13 are each integers of 0 to 4, and when r21 to r23 and r11 to r13 are 2 or more, the structures in parentheses are the same or different from each other.

In one embodiment of the present specification, the aromatic polyamide may include a structure represented by any one or two or more of the following formulas F-1 to F-3, but is not limited thereto.

[Formula F-1]

[Formula F-2]

[Formula F-3]

In the above formulas F-1 to F-3, R'' is a hydroxy group (-OH); or chlorine (-Cl).

When the active layer does not contain fully aromatic polyamide but rather semi-aromatic polyamide or mixed aromatic polyamide of aliphatic and aromatic, the gas separation membrane containing the active layer is made of platinum. (Pt) When the surface was photographed using a scanning electron microscope (SEM) after surface coating, no surface protrusions were observed.

Referring to FIG. 2, when the surface of the gas separation membrane of the present specification was photographed using a scanning electron microscope (SEM) as described above, the surface protrusions observed indicate that the active layer included in the gas separation membrane of the present specification is complete. This is because it contains fully aromatic polyamide. The presence of the surface protrusions increases the surface area where gas contacts the gas separation membrane of the present specification, thereby improving helium permeability.

In this specification, the weight average molecular weight is one of the average molecular weights that are used as a standard for the molecular weight of certain polymer materials where the molecular weight is not uniform, and is a value obtained by averaging the molecular weights of the component molecular species of a polymer compound with a molecular weight distribution by weight fraction. .

The weight average molecular weight can be measured through Gel Permeation Chromatography (GPC) analysis.

In the gas separation membrane according to an exemplary embodiment of the present specification, a peak in the region of 1650 cm ^-1 to 1700 cm ^-1 can be detected by Fourier transform infrared spectrometry (FT-IR). By including a peak in the region of 1650 cm ^-1 to 1700 cm ^-1 , it can be confirmed that -C(=O)- is included in the active layer included in the gas separation membrane.

In one embodiment of the present specification, the helium permeability of the gas separation membrane is 40 to 400 GPU.

In one embodiment of the present specification, the active layer includes pores, and the average pore radius of the pores is 0.239 nm to 0.45 nm.

In one embodiment of the present specification, the active layer includes pores, and the pores may be plural.

The voids may include defects as described above.

In one embodiment of the present specification, the active layer includes pores, and the average pore radius of the pores may be 0.239 nm to 0.45 nm. Preferably, the average pore radius may be 0.25 nm to 0.275 nm. More preferably, the average pore radius may be 0.255 nm to 0.271 nm.

When the average pore radius of the active layer falls within the above range, helium permeability of the gas separation membrane and helium selectivity based on carbon dioxide can be improved. If the average pore radius of the active layer is less than 0.239 nm or more than 0.45 nm, both the helium permeability and the helium selectivity characteristics based on carbon dioxide cannot be improved, and only one characteristic is improved and the remaining characteristics are significantly reduced. You can.

The average pore radius refers to the average value of half the diameter passing through the center of the pores included in the active layer.

The range of pore radius included in the active layer is 0.2 nm to 0.32 nm. In another exemplary embodiment, the range of the pore radius is 0.21 nm to 0.32 nm. In another exemplary embodiment, the range of the pore radius is 0.22 nm to 0.30 nm.

When the range of pore radii included in the active layer satisfies only the above numerical range, helium permeability of the gas separation membrane and helium selectivity based on carbon dioxide can be improved.

The cavity radius can be measured by positron extinction time spectroscopic analysis, which will be described later.

In one embodiment of the present specification, the average pore radius is measured by positron annihilation lifetime spectroscopy (PALS).

Specifically, the measurement of the average pore radius using the positron annihilation time spectroscopic analysis can be obtained by measuring the average lifetime of the positron, calculating it using the following calculation formula, and then calculating the average of all calculated pore radius values. there is.

[formula]

In the above calculation formula,

τ is the average lifetime of the positron (ns), and R is the cavity radius (nm).

In one embodiment of the present specification, the device used for the positron extinction time spectroscopic analysis may be a small positron beam generator PALS-200A manufactured by FUJI IMVAC, but is not limited thereto.

The meaning of the gap radius can also be applied to the above description of the defect.

The average pore radius can be obtained as the average value of the total sum of pore radii calculated using the above calculation formula. Specifically, it can be obtained as the average value of pore radii calculated based on about 5 million pores.

An exemplary embodiment of the present specification includes a porous layer; and an active layer, wherein the active layer is formed by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound, the active layer includes pores, and the average pore radius of the pores is A gas separation membrane of 0.239 nm to 0.45 nm is provided.

Another exemplary embodiment of the present specification includes a porous layer; and a gas separation membrane including an active layer, wherein the active layer includes pores, the average pore radius of the pores is 0.239 nm to 0.45 nm, the helium permeability of the gas separation membrane is 40 to 400 GPU, and the gas separation membrane has a helium permeability of 40 to 400 GPU. A gas separation membrane is provided in which the selectivity for helium is 4 to 55, and the average pore radius is measured by positron annihilation lifetime spectroscopy (PALS).

In one embodiment of the present specification, the active layer includes aromatic polyamide.

Since the active layer is formed by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound, it is possible to laminate and coat the aromatic polyamide while maintaining the durability of the porous layer below the active layer. .

As the active layer includes aromatic polyamide, the average pore spacing of pores included in the active layer can be reduced, thereby increasing the helium permeability and helium selectivity based on carbon dioxide of the gas separation membrane including the active layer. .

In one embodiment of the present specification, the gas separation membrane refers to a barrier membrane capable of selectively separating specific gas molecules from a gas mixture. The gas separation membrane uses the phenomenon that when a gas mixture is contacted on one side and the other side is in a low pressure state, only specific gases in the gas mixture permeate. Specifically, it uses the principle that a specific gas with good affinity to the separator is dissolved on the surface of the separator, then passes through the interior through diffusion and is desorbed from the other side. In this specification, the specific gas molecule may be helium.

The gas mixture may mean containing gases such as hydrogen, helium, carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen, nitrogen, ammonia, sulfur oxides, nitrogen oxides, hydrocarbons such as methane and ethane, and unsaturated hydrocarbons such as propylene and water vapor. there is.

In an exemplary embodiment of the present specification, the description of the gas mixture described above may be applied.

In one embodiment of the present specification, the active layer may be formed by interfacial polymerization of an aqueous solution containing the compound represented by Formula 1-1 and an organic solution containing the acyl halide compound.

In one embodiment of the present specification, the porous layer includes a first porous support and a second porous support. The porous support layer may have a structure in which the second porous support is stacked on the first porous support.

In one embodiment of the present specification, the material included in the first porous support may be used without limitation as long as it is a material used as a support for a gas separation membrane, but is preferably a non-woven fabric. The nonwoven fabric may be made of polyester, polypropylene, nylon, or polyethylene, but is not limited thereto.

In one embodiment of the present specification, the first porous support includes a non-woven fabric.

According to an exemplary embodiment of the present specification, the thickness of the first porous support may be 90 μm to 200 μm, but is not limited thereto and may be adjusted as needed. Additionally, the first porous support may include pores, and the pore size included in the first porous support is preferably 500 nm to 10 μm, but is not limited thereto. The thickness of the first porous support and the size of pores included in the first porous support can be measured using a digital thickness gauge and a porometer, respectively. When the first porous support satisfies the above thickness range, it can maintain appropriate durability as a porous layer of a gas separation membrane. Additionally, when the pores included in the first porous support satisfy the above size range, appropriate durability can be maintained as a porous layer of a gas separation membrane.

In one embodiment of the present specification, the porous layer may include the second porous support formed by applying a hydrophilic polymer solution on the first porous support.

The hydrophilic polymer solution can be formed by dissolving the hydrophilic polymer in a solvent. The hydrophilic polymer may be polysulfone, polyethersulfone, polycarbonate, polyethylene oxide, polyimide, polyetherimide, polyetheretherketone, polypropylene, polymethylpentene, polymethylchloride, or polyvinylidene fluoride. However, it is not necessarily limited to these. Specifically, the hydrophilic polymer may be polysulfone.

The solvent included in the hydrophilic polymer solution can be used without limitation as long as it is a solvent that can dissolve the hydrophilic polymer. For example, acetone, acetonitrile, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), or hexamethylphosphoramide (HMPA). It is not limited. The hydrophilic polymer may be included in an amount of 10% to 30% by weight based on the total weight of the hydrophilic polymer solution, and when the above range is satisfied, the second porous support can maintain appropriate durability as a porous layer of a gas separation membrane.

In one embodiment of the present specification, the method of applying the hydrophilic polymer solution may be a method such as dipping, spraying, or coating, but is not limited thereto.

In one embodiment of the present specification, the thickness of the second porous support may be 30 μm to 160 μm. When the thickness of the second porous support satisfies the above range, appropriate durability as a porous layer of a gas separation membrane can be maintained. The thickness of the second porous support can be measured using a screen observed with a scanning electron microscope (SEM).

In one embodiment of the present specification, the active layer is a polyamide active layer. In another exemplary embodiment, the active layer is an aromatic polyamide active layer.

In one embodiment of the present specification, the compound represented by Formula 1-1 is an amine compound, and the aqueous solution containing the compound represented by Formula 1-1 may be an aqueous solution containing an amine compound.

In one embodiment of the present specification, the active layer may form the aromatic polyamide through interfacial polymerization of an aqueous solution containing the compound represented by Formula 1-1 and an organic solution containing the acyl halide compound.

In one embodiment of the present specification, the content of the amine compound may be 0.1% by weight or more and 20% by weight or less, preferably 0.5% by weight to 15% by weight, based on the total weight of the aqueous solution containing the amine compound. Preferably it may be 1% by weight to 10% by weight. When the content of the amine compound satisfies the above range, a uniform polyamide active layer can be manufactured.

In an exemplary embodiment of the present specification, the aqueous solution containing the amine compound may further include a surfactant if necessary.

During interfacial polymerization of the polyamide active layer, polyamide is rapidly formed at the interface between the aqueous solution layer containing the amine compound and the organic solution layer containing the acyl halide compound. At this time, the surfactant is an aqueous solution containing the amine compound. By making the layer thin and uniform, the amine compound present in the aqueous solution layer containing the amine compound can easily move to the organic solution layer containing the acyl halide compound to form a uniform polyamide active layer.

The surfactant may be selected from nonionic, cationic, anionic and amphoteric surfactants.

The surfactant is, for example, sodium lauryl sulfate (SLS), alkyl ether sulfate, alkyl sulfate, olefin sulfonate, alkyl ether carboxylate, sulfosuccinate, aromatic sulfonate, octylphenol ethoxyl esters, ethoxylated nonylphenols, alkyl poly(ethylene oxide), copolymers of poly(ethylene oxide) and poly(propylene oxide), alkyl polyglucosides such as octyl glucoside or decyl maltoside, cetyl alcohol or oleyl. It may be selected from fatty alcohols and alkyl betaines such as alcohol, cocamide MEA, cocamide DEA, alkyl hydroxy ethyl dimethyl ammonium chloride, cetyltrimethyl ammonium bromide or chloride, and hexadecyltrimethylammonium bromide or chloride. Specifically, the surfactant may be SLS, octylphenol ethoxylate, or ethoxylated nonylphenol.

In particular, when using sodium lauryl sulfate (SLS) as the surfactant, the sodium lauryl sulfate (SLS) has a high affinity for water and oil (Hydrophile-Lipophile Balance, HLB) and is easily soluble in water. Because the Critical Michelle Concentration (CMC) is high, even if added in excessive amounts, the formation of the polyamide active layer is not inhibited.

In one embodiment of the present specification, the surfactant may be 0.005% by weight to 0.5% by weight based on the total weight of the aqueous solution containing the amine compound. When the surfactant satisfies the above range and is included in an aqueous solution containing the amine compound, a uniform polyamide active layer can be formed.

In an exemplary embodiment of the present specification, the aqueous solution containing the amine compound may additionally include a salt if necessary.

During interfacial polymerization of the polyamide active layer, polyamide is rapidly formed at the interface between the aqueous solution layer containing the amine compound and the organic solution layer containing the acyl halide compound. At this time, the salt captures HCl generated during interfacial polymerization. It plays the role of capture.

The salt may be, for example, singly or in a mixture selected from the group consisting of trimethylamine, triethylamine, camphorsulfonic acid, and dodecylbenze sulfonic acid.

Preferably, the salt may be a salt mixture of triethylamine, camphorsulfonic acid, and dodecylbenze sulfonic acid.

In one embodiment of the present specification, the salt may be the salt mixture, and based on the total weight of the salt mixture, 1 to 10% by weight of the trilethylamine, 1 to 10% by weight of the camphorsulfonic acid, and the dodecyl It may contain 0.1 to 5% by weight of benzene sulfonic acid.

When the content of the salt mixture satisfies the above range, HCl generated during interfacial polymerization of the polyamide active layer according to the present specification can be smoothly captured.

In one embodiment of the present specification, the salt may be 1% by weight to 15% by weight based on the total weight of the aqueous solution containing the amine compound. Preferably, the salt may be 3% to 12% by weight based on the total weight of the aqueous solution containing the amine compound. When the salt satisfies the above range and is included in an aqueous solution containing the amine compound, a uniform polyamide active layer can be formed.

In one embodiment of the present specification, the solvent of the aqueous solution containing the amine compound may be water. Specifically, in an aqueous solution containing the amine compound, the remainder excluding the amine compound, the surfactant, and the salt may be water.

In one embodiment of the present specification, the method of forming an aqueous solution layer containing the amine compound on the porous layer is not particularly limited, and an aqueous solution layer containing the amine compound can be formed on the porous layer. Any method can be used without restrictions. Specifically, spraying, application, dipping, or dripping may be used, but are not limited thereto.

In one embodiment of the present specification, the aqueous solution layer containing the amine compound may be additionally subjected to the step of removing the aqueous solution containing an excess amine compound, if necessary.

The aqueous solution layer containing the amine compound formed on the porous layer may be distributed unevenly when the aqueous solution containing the amine compound present on the porous layer is too much, and the aqueous solution containing the amine compound is heterogeneous. If distributed unevenly, a non-uniform polyamide active layer may be formed by subsequent interfacial polymerization.

Therefore, it is preferable to form an aqueous solution layer containing the amine compound on the porous layer and then remove the aqueous solution containing an excess amine compound. The method of removing the aqueous solution containing the excess amine compound is not particularly limited, but may be performed using, for example, a sponge, an air knife, nitrogen gas blowing, natural drying, or a compression roll.

In the present specification, the meaning of “on the porous layer” may mean “on the second porous support.”

In one embodiment of the present specification, it is preferable that the organic solvent included in the organic solution containing the acyl halide compound does not participate in the interfacial polymerization reaction. The organic solvent may include at least one selected from aliphatic hydrocarbon solvents, for example, freons, alkanes having 5 to 12 carbon atoms, and isoparaffin-based solvents that are alkane mixtures. Specifically, hexane, heptane, octane, nonane, decane, undecane, dodecane, cyclohexane, IsoPar (Exxon), IsoPar G (Exxon), ISOL-C (SK Chem), or ISOL-G (Exxon) may be used. However, it is not limited to this.

In one embodiment of the present specification, the content of the acyl halide compound is 0.05% to 1% by weight, preferably 0.05% to 0.75%, more preferably, based on the total weight of the organic solution containing the acyl halide compound. may be 0.05% to 0.5%. When the content of the acyl halide compound satisfies the above range, a uniform polyamide active layer can be manufactured.

In one embodiment of the present specification, an organic solution layer containing an acyl halide compound can be formed on an aqueous solution layer containing the amine compound using an organic solution containing the acyl halide compound.

In one embodiment of the present specification, the method of forming an organic solution layer containing the acyl halide compound on the aqueous solution layer containing the amine compound formed on the porous layer is not particularly limited, and the amine compound Any method that can form an organic solution layer containing the acyl halide compound on an aqueous solution layer containing can be used without particular limitation. Specifically, spraying, application, dipping, or dripping may be used, but are not limited thereto.

In one embodiment of the present specification, the remainder of the organic solution containing the acyl halide compound, excluding the acyl halide compound, may be the organic solvent.

In one embodiment of the present specification, the thickness of the active layer is 100 nm to 500 nm. The thickness of the active layer may vary depending on the concentration and coating conditions of the active layer forming composition including an aqueous solution containing the amine compound and an organic solution containing the acyl halide compound used to form the active layer. When the thickness of the active layer satisfies the above range, the permeability and selectivity of the gas separation membrane desired in this specification can be obtained. Specifically, when the thickness of the active layer is less than 100 nm, the selectivity of helium relative to carbon dioxide may decrease, and when the thickness of the active layer is more than 500 nm, helium permeability may decrease.

The thickness of the active layer can be measured using a screen observed with a scanning electron microscope (SEM). Specifically, a cross-section of a 0.2 cm sample is cut through a microtome, coated with platinum (Pt), and the thickness of the active layer can be measured using a scanning electron microscope (SEM) and calculated as an average value. .

In one embodiment of the present specification, the gas separation membrane may be a flat sheet or spiral-wound type. Gas separation membranes include flat-sheet, spiral-wound, tube-in-shell, or hollow-fiber forms, but one embodiment of the present specification is a flat sheet. ) or spiral-wound type is preferred.

An exemplary embodiment of the present specification provides a gas separation membrane module including one or more of the gas separation membranes.

In an exemplary embodiment of the present specification, the number of gas separation membranes included in the gas separation membrane module may be 1 to 50, specifically 20 to 30, and more specifically 25 to 30.

The gas separation membrane module may mean that the gas separation membrane according to an exemplary embodiment of the present specification is integrated into a pressure vessel. Specifically, the gas separation membrane module is manufactured by rolling one or more of the gas separation membranes around an inner core tube and then final winding the surface with fiber reinforced plastic. You can.

As long as the gas separation membrane module includes the gas separation membrane according to the present specification, other configurations and manufacturing methods are not particularly limited, and general means known in the field can be employed without limitation.

An exemplary embodiment of the present specification includes forming a second porous support by applying a hydrophilic polymer solution on a first porous support; and forming an active layer on the second porous support by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound, wherein the active layer is formed into pores. It provides a method of manufacturing a gas separation membrane including, and the average pore radius of the pores is 0.239 nm to 0.45 nm.

In the method of manufacturing the gas separation membrane, the description of the porous layer and the active layer is as described above.

In the step of forming a second porous support by applying a hydrophilic polymer solution on the first porous support, the application method may include dipping, spraying, or coating, but is not limited thereto. The hydrophilic polymer solution is as described above.

In one embodiment of the present specification, the step of forming an active layer by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound on the second porous support includes: It may include applying an aqueous solution containing an amine compound: and applying an organic solution containing the acyl halide compound.

The application method is not particularly limited, but methods such as dipping, spraying, or coating may be used.

In another embodiment of the present specification, the step of forming an active layer by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound on the second porous support includes forming an active layer on the porous layer. Forming an aqueous solution layer containing an amine compound; And it may include contacting an organic solution containing the acyl halide compound on the aqueous solution layer containing the amine compound.

When the aqueous solution containing the amine compound comes into contact with the organic solution containing the acyl halide compound, the amine compound and the acyl halide compound react on the surface of the second porous support to produce polyamide by interfacial polymerization. and a polyamide active layer containing the produced polyamide can be formed. Thereafter, the polyamide active layer may be adsorbed to the second porous support to form a thin film. The contact method is not particularly limited, but methods such as dipping, spraying, or coating may be used.

Figure 1 illustrates the structure of a gas separation membrane according to an exemplary embodiment of the present specification. 1 shows a second porous support 11 formed by applying a hydrophilic polymer solution on a first porous support 10, and an aqueous solution containing an amine compound and an acyl halide compound on the second porous support 11. A gas separation membrane including an active layer 12 formed by interfacial polymerization of an organic solution is exemplified. The structure including the first porous support 10 and the second porous support 11 is a porous layer. The active layer 12 may include pores, and the average pore radius of the pores is 0.239 nm to 0.45 nm, does not include defects with an average pore radius of 0.33 nm or more, and contains helium based on carbon dioxide in the gas separation membrane. The selectivity is 4 or more.

Figure 2 is a surface photograph of a gas separation membrane according to an exemplary embodiment of the present specification measured with a scanning electron microscope (SEM) after coating with platinum (Pt). Porous layer of the present specification; And in the gas separation membrane including an active layer, when the active layer includes aromatic polyamide, when the surface is measured using a scanning electron microscope (SEM) after coating the gas separation membrane of the present invention with platinum (Pt), surface protrusions are observed. It can be seen that exists. The presence of the surface protrusions increases the surface area where gas contacts the gas separation membrane of the present specification, thereby improving helium permeability. The active layer included in the gas separation membrane according to FIG. 2 is manufactured using an amine compound containing 6% by weight of the amine compound based on the total weight of the aqueous solution containing the amine compound.

Hereinafter, in order to explain the present specification in detail, examples will be given in detail. However, the embodiments according to the present specification may be modified into various other forms, and the scope of the present specification is not to be construed as being limited to the embodiments described in detail below. The embodiments of this specification are provided to more completely explain the present specification to those with average knowledge in the art.

Example 1.

Polysulfone solids were added to DMF (N,N-dimethylformamide) solution and dissolved at 80°C to 85°C for more than 12 hours to obtain a uniform hydrophilic polymer solution. The polysulfone solid content in the hydrophilic polymer solution was 18% by weight based on the total weight of the solution.

The solution was cast to a thickness of 150 μm on a 95 μm to 100 μm thick polyester nonwoven fabric (first porous support) to form a polymer coating layer (second porous support). Then, the cast nonwoven fabric was placed in water to prepare a porous layer.

In order to form an active layer on the porous layer, 8% by weight of a compound represented by the following formula 1-1 based on the total weight of the aqueous solution containing the amine compound, and 0.5% by weight of sodium lauryl sulfate (SLS) as a surfactant. % by weight, an aqueous solution containing 10 wt% of the salt mixture, and 81.5 wt% of water was applied to form an aqueous solution layer containing an amine compound. The salt mixture is a mixture containing triethylamine, camphorsulfonic acid, and dodecylbenze sulfonic acid, and 5% by weight of trilethylamine each based on the total weight of the salt mixture. , 4% by weight of camphorsulfonic acid and 1% by weight of dodecylbenzene sulfonic acid.

[Formula 1-1]

In Formula 1-1, R14 is a methyl group, r14 is 0, and m is 2.

Thereafter, based on the total weight of the organic solution containing the acyl halide compound, an organic solution containing an acyl halide compound containing 0.3% by weight of trimesoyl chloride (TMC) and 99.7% by weight of hexane was mixed with the amine compound. was applied on an aqueous solution layer to form an organic solution layer containing the acyl halide compound, and an active layer was formed to a thickness of 250 nm by performing interfacial polymerization, followed by drying in an oven at 90°C for 5 minutes. Through this, a flat membrane gas separation membrane was manufactured.

The thickness of the manufactured active layer was calculated as the average value by cutting a cross-section of a 0.2 cm ² sample using a microtome, coating it with platinum (Pt), and measuring each thickness using a scanning electron microscope (SEM). It was confirmed.

Example 2.

In Example 1, based on the total weight of the aqueous solution containing the amine compound, 6% by weight of the compound represented by Formula 1-1, 0.5% by weight of Sodium Lauryl Sulphate (SLS) as a surfactant, and 10% salt mixture. A gas separation membrane was prepared in the same manner as Example 1, except that an aqueous solution containing 83.5% by weight of water was used.

Example 3.

In Example 1, based on the total weight of the aqueous solution containing the amine compound, 4% by weight of the compound represented by Formula 1-1, 0.5% by weight of Sodium Lauryl Sulphate (SLS) as a surfactant, and 10% salt mixture. A gas separation membrane was prepared in the same manner as Example 1, except that an aqueous solution containing 85.5% by weight of water was used.

Comparative Example 1.

A gas separation membrane (BW30-400) obtained from Dow was immersed in DI (Deionized) water at 90°C for 30 minutes. The immersed gas separation membrane was dried in an oven at 60°C for 10 minutes to prepare a gas separation membrane.

Comparative Example 2.

In Comparative Example 1, a gas separation membrane obtained from Dow was prepared by immersing and drying in the same manner as Comparative Example 1, except that DOW TW30-1812-100HR product was used instead of BW30-400.

Experiment example.

(Measurement of pore radius of active layer)

The average pore radius and pore radius range included in the active layer of the gas separation membrane prepared in the above Examples and Comparative Examples were measured by positron annihilation lifetime spectroscopy (PALS) and are listed in Table 1 below.

Specifically, it was measured using the following calculation formula.

[formula]

In the above calculation formula, τ is the average lifetime of the positron (ns), and R is the cavity radius (nm). The pore radius range was calculated using the above formula, and the average pore radius is the average of the calculated pore radius values.

In addition, the concentration (% by weight) of the amine compound represented by Formula 1 is summarized and listed in Table 1 below.

PALS measurement results Concentration (% by weight) of the amine compound represented by Formula 1 in an aqueous solution containing the amine compound τ (average lifetime of a positron, ns) R (average pore radius, nm) Measured pore radius range (nm) Example 1 1.69 0.255 0.20~0.32 8 Example 2 1.72 0.258 0.22~0.30 6 Example 3 1.85 0.271 0.21~0.32 4 Comparative Example 1 1.53 0.238 0.15~0.33 - Comparative Example 2 1.23 0.201 0.15~0.25,0.36~0.45 -

(Evaluation of helium permeability and selectivity)

After fastening the manufactured gas separation membrane to a gas separation membrane cell (area of 14 cm ² ) at room temperature (25°C), a single gas at a certain pressure is injected into the upper part of the cell using a pressure regulator to separate the upper part of the membrane and the upper part of the membrane. Gas permeation was induced due to the pressure difference at the bottom. Specifically, the evaluation was conducted at 25°C and 80 psi under single gas conditions (helium 100 vol% or carbon dioxide 100 vol%).

At this time, the flow rate of the gas passing through the gas separation membrane cell was measured using a bubble flow meter, and the helium permeability and carbon dioxide permeability of the gas separation membrane were evaluated considering the stabilization time (> 1 hour). It is listed in Table 2.

Transmittance Selectivity (He/CO ₂ ) P _He (GPU) P _CO2 (GPU) Example 1 235 36.1 6.5 Example 2 301 50.1 6 Example 3 356 65.9 5.4 Comparative Example 1 427 129 3.3 Comparative Example 2 383 111 3.4

In Table 2, selectivity (He/CO ₂ ) refers to the selectivity of helium based on carbon dioxide. According to Table 2, the gas separation membranes according to Examples 1 to 3 do not contain defects larger than 0.33 nm than the gas separation membranes according to Comparative Examples 1 and 2, and thus have a higher selectivity for helium based on carbon dioxide, and are described herein. It was confirmed that the gas separation membrane according to the present invention exhibits excellent selectivity.

In a typical gas separation membrane, when the permeability is high, the selectivity tends to be low. However, it was confirmed that the gas separation membrane according to an exemplary embodiment of the present specification has the advantage of greatly increasing the selectivity of helium relative to carbon dioxide while maintaining relatively high helium permeability.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and can be implemented with various modifications within the scope of the claims and the detailed description of the invention, and this also falls within the scope of the invention. .

10: First porous support
11: Second porous support
12: active layer

Claims (12)

porous layer; And a gas separation membrane comprising an active layer,
The active layer includes polyamide,
The polyamide is a gas separation membrane that is an aromatic polyamide,
The active layer includes pores, the pores have a pore radius of 0.2 nm to 0.32 nm, and the pores have an average pore radius of 0.25 nm to 0.275 nm,
The helium permeability of the gas separation membrane is 40 to 400 GPU,
The selectivity of helium based on carbon dioxide of the gas separation membrane is 4 to 55,
The average pore radius refers to the average value of half the diameter passing through the center of the pores included in the active layer, and is measured by positron annihilation lifetime spectroscopy (PALS). The gas separation membrane of claim 1, wherein the aromatic polyamide comprises a structure represented by the following formula (1):
[Formula 1]

In Formula 1,
R1 is hydrogen; Substituted or unsubstituted alkyl group; -SOOH; or -COOH,
r1 is an integer from 1 to 4, and when r1 is 2 or more, R1 is the same or different. delete delete delete porous layer; And a gas separation membrane comprising an active layer,
The active layer is formed by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound,
The active layer includes pores, the pores have a pore radius of 0.2 nm to 0.32 nm, and the pores have an average pore radius of 0.25 nm to 0.275 nm,
The helium permeability of the gas separation membrane is 40 to 400 GPU,
The selectivity of helium based on carbon dioxide of the gas separation membrane is 4 to 55,
The average pore radius refers to the average value of half the diameter passing through the center of the pores included in the active layer, and is measured by positron annihilation lifetime spectroscopy (PALS). delete The gas separation membrane of claim 6, wherein the active layer includes aromatic polyamide. The gas separation membrane according to any one of claims 1, 2, and 6, wherein the active layer has a thickness of 100 nm to 500 nm. The gas separation membrane according to any one of claims 1, 2, and 6, wherein the gas separation membrane is a flat sheet or spiral-wound type. A gas separation membrane module comprising at least one gas separation membrane of any one of claims 1, 2, and 6. forming a second porous support by applying a hydrophilic polymer solution on the first porous support; and
The gas separation membrane according to any one of claims 1, 2, and 6, comprising forming an active layer by interfacial polymerization of an aqueous solution containing an amine compound and an organic solution containing an acyl halide compound on the second porous support. As a manufacturing method,
The active layer includes pores, the pores have a pore radius of 0.2 nm to 0.32 nm, and the pores have an average pore radius of 0.25 nm to 0.275 nm,
The average pore radius refers to the average value of half the diameter passing through the center of the pores included in the active layer, and is measured by positron annihilation lifetime spectroscopy (PALS).