KR102457839B1 - Preparation mehtod for separation membrane and separation membrane prepared thereof - Google Patents

Abstract

The present specification provides a porous support layer comprising at least one polymer selected from polysulfone, polyethersulfone, polyetherethersulfone and polyphenylsulfone; a gutter layer formed on the porous support layer and including a silicon-based compound; and an active layer formed on the gutter layer and comprising acetylated methyl cellulose, wherein the peak strength of the C=O bond compared to the peak strength of the S=O bond measured on the surface of the separator is 0.6 or more, and a separation membrane thereof It relates to a manufacturing method.

Description

Method for manufacturing a separation membrane and a separation membrane manufactured thereby

The present specification relates to a method for manufacturing a separation membrane and a separation membrane manufactured thereby.

Composite membranes (composite membranes or membranes) are currently being applied to various fields, such as gas separation membranes, water treatment membranes, ion separation membranes, and secondary battery separation membranes. The material used for these separation membranes is slightly different depending on the applicable field of application.

In particular, as interest in the environment increases, research on gas separation technology is being actively conducted. Among them, gas separation by a gas separation membrane is a method with superior energy efficiency and high stability compared to a distillation method and a high pressure adsorption method.

The base separation membrane is composed of a support layer and an active layer, and is a membrane that selectively separates a gas from a mixed gas by using the structural characteristics of the active layer. Therefore, gas permeability and selectivity are used as important indicators of membrane performance, and these performances are greatly affected by the polymer material constituting the active layer.

Although a lot of development has been made since commercial polymer membranes were first introduced in the 1970s, it still remains a challenge to overcome the trade-off between permeability and selectivity. Therefore, there is a need to develop a method capable of increasing the transmittance without sacrificing selectivity.

Korean Publication No. 10-2013-0137238

An object of the present specification is to provide a method for manufacturing a separation membrane having excellent helium permeability and selectivity, and a separation membrane manufactured thereby.

An exemplary embodiment of the present specification includes a porous support layer comprising at least one polymer selected from polysulfone, polyethersulfone, polyetherethersulfone, and polyphenylsulfone;

a gutter layer formed on the porous support layer and including a silicon-based compound; and

An active layer formed on the gutter layer and comprising Acetylated Methyl Cellulose (AMC)

As a separation membrane comprising:

To provide a separation membrane having a T value of 0.6 or more on the surface of the separation membrane.

[Equation 1]

T=(peak intensity of C=O bond)/(peak intensity of S=O bond)

In Equation 1, the peak intensity means the absorption intensity measured by Fourier Transform Infrared Spectrometer (FT-IR) and

The C=O bond is a bond present in the active layer, and the S=O bond is a bond present in the porous support layer.

In addition, an exemplary embodiment of the present specification provides a separation membrane module including at least one separation membrane.

In addition, forming a porous support layer by applying a solution containing at least one polymer selected from among polysulfone, polyethersulfone, polyetherethersulfone and polyphenylsulfone on the porous substrate;

forming a gutter layer by applying a composition for forming a gutter layer including a silicone-based compound on the porous support layer; and

Forming an active layer by applying a composition for forming an active layer comprising acetylated methyl cellulose (AMC, Acetylated Methyl Cellulose) on the gutter layer,

Based on 100 wt% of the composition for forming the active layer, the content of the acetylated methyl cellulose provides a method for manufacturing a separator of 0.5 wt% to 5 wt%.

In addition, an exemplary embodiment of the present specification provides a separation membrane manufactured according to the above manufacturing method.

The separation membrane according to an exemplary embodiment herein has excellent performance in selectively separating carbon dioxide gas from natural gas or a gas mixture.

1 illustrates a separator according to an exemplary embodiment of the present specification.

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

In the present specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, the present specification will be described in more detail.

In an exemplary embodiment of the present specification, the separator includes a porous support layer comprising at least one polymer selected from polysulfone, polyethersulfone, polyetherethersulfone, and polyphenylsulfone; a gutter layer formed on the porous support layer and including a silicon-based compound; and an active layer formed on the gutter layer and containing acetylated methyl cellulose (AMC, Acetylated Methyl Cellulose), wherein the following T value of the surface is 0.6 or more.

[Equation 1]

T=(peak intensity of C=O bond)/(peak intensity of S=O bond)

In Equation 1, the peak intensity means the absorption intensity measured by a Fourier transform infrared spectrometer (FT-IR),

The C=O bond is a bond present in the active layer, and the S=O bond is a bond present in the porous support layer.

In the present specification, the surface of the separator means a surface in the direction in which the active layer is laminated. For example, as shown in FIG. 1, it is a configuration including a porous substrate 10, a porous support layer 20, a gutter layer 30, an active layer 40, and a protective layer 50, and an additional configuration on the protective layer 50 is If not, the surface of the separator means the surface of the protective layer 50, not the surface of the porous substrate 10. In addition, if the configuration does not include a protective layer and there is no additional configuration on the active layer, the surface of the separator means the surface of the active layer.

Specifically, the peak intensity of the functional group bond included in the separator can be measured through the ATR-FTIR method in which the thickness of each layer does not affect the strength.

In general, an expensive separation method such as an amine wet method is used for carbon dioxide gas separation, and the separation of carbon dioxide gas by a separation membrane is limited by applying a hollow fiber membrane using a cellulose-based polymer.

The inventors of the present invention have found that the gas separation performance is controlled according to the concentration of acetylated methyl cellulose used in forming the active layer. In particular, when the T value calculated by Equation 1 on the surface of the separation membrane is 0.6 or more, the permeability of carbon dioxide gas and It was confirmed that the selectivity can exhibit a high value at the same time.

In particular, the higher the AMC content in the active layer coating solution, the higher the T value, and in this case, it was confirmed that the selectivity of the carbon dioxide gas to the methane gas can be achieved.

In one embodiment of the present specification, the separation membrane is a gas separation membrane, a water treatment separation membrane, or an ion separation membrane, preferably a gas separation membrane.

In an exemplary embodiment of the present specification, the gas separation membrane refers to a barrier separation membrane capable of selectively separating specific gas molecules from a gas mixture. The gas separation membrane uses a phenomenon in which only a specific gas in the gas mixture permeates when the gas mixture is brought into contact with one side and the other side is in a low pressure state. Specifically, it uses the principle that a specific gas having good affinity with 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 the present specification, the specific gas molecule is carbon dioxide.

In one embodiment of the present specification, the gas mixture is hydrogen; helium; carbon monoxide; carbon dioxide; hydrogen sulfide; Oxygen; nitrogen; ammonia; sulfur oxides; nitrogen oxides; hydrocarbon gases such as methane and ethane; unsaturated hydrocarbon gases such as propylene; and water vapor.

In the exemplary embodiment of the present specification, the gas mixture may refer to a gas mixture including carbon dioxide and methane.

In one embodiment of the present specification, the gas mixture may mean natural gas.

In an exemplary embodiment of the present specification, the peak intensity of the C = O bond and the peak intensity of the S = O bond may mean the intensity of the absorption peak appearing at 1754 cm ^-1 and 1175 cm ^-1 in the FT-IR absorption spectrum, respectively. .

In an exemplary embodiment of the present specification, the C = O bonding means a C = O bonding portion of the AMC included in the active layer.

In an exemplary embodiment of the present specification, the polymer may be one or more selected from polysulfone, polyethersulfone, polyetherethersulfone, and polyphenylsulfone, and specifically may be polysulfone.

In the exemplary embodiment of the present specification, the polysulfone may be represented by the following Chemical Formula 1, and the S=O bond means an S=O bond moiety in the following Chemical Formula 1.

[Formula 1]

In Formula 1, k is an integer of 1 to 1,000.

In one embodiment of the present specification, the T value of the surface of the separator is 0.6 or more and 2.0 or less, preferably 0.7 or more and 1.8 or less, and more preferably 0.7 or more and 1.5 or less.

In one embodiment of the present specification, the porous support layer may be prepared by applying a polymer solution on a porous substrate.

In one embodiment of the present specification, the porous substrate may be used without limitation as long as it is a material used as a support for the separator, for example, polyester, polypropylene, nylon, polyethylene, or non-woven fabric. Specifically, the porous substrate may be a nonwoven fabric.

According to an exemplary embodiment of the present specification, the polymer solution may be prepared by dissolving one or more polymers selected from among polysulfone, polyethersulfone, polyetherethersulfone and polyphenylsulfone in a solvent. The solvent may be used without limitation as long as it is a solvent capable of dissolving the polymer. For example, acetone, acetonitrile, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dimethylformamide (DMF) and hexamethylphosphoamide (HMPA), etc. can be used, The present invention is not limited thereto. The polymer may be included in an amount of 10 wt% to 30 wt% based on 100 wt% of the polymer solution.

In an exemplary embodiment of the present specification, the thickness of the porous support layer may be 20 µm to 100 µm. In an exemplary embodiment of the present specification, the gutter layer smoothes the curved surface of the porous support layer to wet the active layer solution. It helps the uniform formation of the active layer by increasing the uniformity of the

In the exemplary embodiment of the present specification, the gutter layer may be formed by applying a composition for forming a gutter layer including a silicon-based compound on the porous support layer.

In one embodiment of the present specification, the silicone-based compound is polydimethylsiloxane (PDMS), poly(1-trimethylsilyl-1-propyne) (Poly(1-trimethylsilyl-1-propyne), PTMSP), and poly At least one selected from among octylmethylsiloxane (POMS), preferably polydimethylsiloxane.

In an exemplary embodiment of the present specification, the thickness of the gutter layer may be 0.01 μm to 1 μm, and when it is less than 0.01 μm, the effect of alleviating the surface roughness may be insignificant, and when it exceeds 1 μm, the transmittance is significantly reduced. There is this.

In one embodiment of the present specification, the polydimethylsiloxane is sylgard 184 of Dow corning.

In an exemplary embodiment of the present specification, the active layer may be formed by applying a composition for forming an active layer including acetylated methyl cellulose on the gutter layer. Acetylated methyl cellulose has the advantage of easy coating while securing a certain level of selectivity through a low-viscosity solution compared to other cellulosic compounds.

In an exemplary embodiment of the present specification, the thickness of the active layer may be 100 nm to 2,000 nm, and when it is less than 100 nm, there is a problem of low selectivity, and when it exceeds 2,000 nm, there is a problem that the transmittance is greatly reduced.

The thickness of the gutter layer and the active layer may be measured using a screen observed with a scanning electron microscope (SEM). Specifically, a cross section of a sample of 0.2 cm ² was cut through a microtome, coated with platinum (Pt), and then the thickness of the gutter layer and the active layer was measured using a scanning electron microscope (SEM), and the average value can be calculated.

In an exemplary embodiment of the present specification, based on 100 wt% of the active layer, the content of the acetylated methyl cellulose is 95 wt% to 99.995 wt%, and the remainder may be a residual solvent.

In an exemplary embodiment of the present specification, the separator further includes a protective layer formed on the active layer and including polydimethylsiloxane (PDMS).

In an exemplary embodiment of the present specification, the protective layer comprises 0.005 wt% to 5 wt% of a surfactant, 0.005 wt% to 5 wt% of a residual solvent and the balance of polydimethylsiloxane based on 100 wt% of the protective layer, , The surfactant and solvent follow the description of the surfactant and solvent of the composition for forming a protective layer to be described later.

In one embodiment of the present specification, the permeability of the carbon dioxide gas of the separation membrane is 30GPU to 130GPU (Gas Permeation Unit, 10 ^-6 cm ³ (STP)/cm ² ·s·cmHg), preferably 48GPU to 125GPU. have. The permeability of the carbon dioxide gas is a single carbon dioxide gas at a pressure of 14 psi to 600 psi; Alternatively, it is measured by permeating a mixed gas containing carbon dioxide and methane from the protective layer toward the porous support layer. Specifically, the mixed gas is a mixed gas containing 0.001 vol% to 10 vol% of helium, 0.001 vol% to 40 vol% of carbon dioxide, 1 vol% to 45 vol% of nitrogen, and 5 vol% to 9 vol% of methane.

In one embodiment of the present specification, the permeability of the methane gas of the separation membrane may be 1GPU to 15GPU, preferably 2.1GPU to 7.7GPU. The permeability of the methane gas is methane single gas at a pressure of 14 psi to 600 psi; Alternatively, it is measured by permeating a mixed gas containing carbon dioxide and methane from the protective layer toward the porous support layer. Specifically, the mixed gas is a mixed gas containing 0.001 vol% to 10 vol% of helium, 0.001 vol% to 40 vol% of carbon dioxide, 1 vol% to 45 vol% of nitrogen, and 5 vol% to 98 vol% of methane.

The permeability refers to the mass transfer rate, and the permeability of the carbon dioxide gas and the methane gas is a bubble flow meter at 25° C. to 60° C., 14 psi to 600 psi, which are standard temperature and pressure (STP) conditions. ) can be measured.

In an exemplary embodiment of the present specification, the selectivity of carbon dioxide to methane of the separation membrane may be 10 or more and 30 or less, preferably 14 or more and 30 or less, and more preferably 14.6 or more and 22.7 or less. The selectivity of carbon dioxide to methane is calculated as a ratio of permeability of carbon dioxide gas to permeability of methane gas.

When the separation membrane satisfies the permeability and selectivity at the same time, it is possible to maximize the selectivity while reducing the gas separation process cost.

In the separation membrane, the higher the transmittance and the selectivity at the same time, the better, but most membrane materials have a trade-off relationship between the transmittance and the selectivity. The separation membrane according to an exemplary embodiment of the present specification may improve the trade-off between permeability and selectivity. That is, the separation membrane according to an exemplary embodiment of the present specification can maintain a relatively high carbon dioxide permeability, and can greatly increase selectivity.

1 shows a porous support layer 20 formed by coating a polymer solution on a porous substrate 10, a gutter layer 30 provided on the porous support layer 20 and containing a silicon-based compound, and the gutter layer 30. The active layer 40 formed thereon and the protective layer 50 formed on the active layer 40 are exemplified. The separation membrane according to an embodiment of the present specification may further include an additional configuration in the configuration of FIG. 1 .

In an exemplary embodiment of the present specification, the separation membrane may be a gas separation membrane, and the gas separation membrane may be a flat sheet or spiral-wound type. The gas separation membrane includes a flat-sheet, spiral-wound, tube-in-shell, or hollow-fiber type, but an exemplary embodiment of the present specification is a flat sheet ) or spiral-wound is preferred.

In one embodiment of the present specification, the separation membrane module may include one or more of the above-described separation membranes.

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

The gas separation membrane module may mean that the separation membrane according to an exemplary embodiment of the present specification is integrated into a pressure vessel. Specifically, one or more of the separation membranes are wound around an inner core tube and rolled, and then finally wound with fiber reinforced plastic on the surface to manufacture a gas separation membrane module. .

As long as the separation membrane module includes a separation membrane according to an exemplary embodiment of the present specification, other configurations and manufacturing methods are not particularly limited, and general means known in this field may be employed without limitation.

In an exemplary embodiment of the present specification, the method for manufacturing a separator is formed by coating a solution containing at least one polymer selected from among polysulfone, polyethersulfone, polyetherethersulfone and polyphenylsulfone on a porous substrate to form a porous support layer. step; forming a gutter layer by applying a composition for forming a gutter layer including a silicone-based compound on the porous support layer; and applying a composition for forming an active layer comprising acetylated methyl cellulose (AMC, Acetylated Methyl Cellulose) on the gutter layer to form an active layer, wherein 100 wt% of the composition for forming the active layer is based on the acetylation The content of methyl cellulose is 0.5 wt % to 5 wt %.

For each configuration of the method for manufacturing the separation membrane, the description of the above-described separation membrane may be cited.

In an exemplary embodiment of the present specification, the T value of the surface of the separator may be controlled by the concentration of the composition for forming an active layer.

In an exemplary embodiment of the present specification, based on 100 wt% of the composition for forming the active layer, the content of the acetylated methyl cellulose is 0.5 wt% to 3 wt%, preferably 0.5 wt% to 1.5 wt%.

When the content of the acetylated methyl cellulose is less than 0.5 wt%, there is a problem of very low selectivity, and when it exceeds 5 wt%, there is a problem of very low transmittance.

In one embodiment of the present specification, the composition for forming the active layer further comprises nitromethane as a solvent.

In an exemplary embodiment of the present specification, the remainder of the composition for forming an active layer except for AMC may be a solvent.

In an exemplary embodiment of the present specification, based on 100 wt% of the composition for forming a gutter layer, the content of the silicone-based compound is 0.5 wt% to 5 wt%, preferably 1 wt% to 3 wt%.

When the content of the silicone-based compound is less than 0.5 wt%, it may not function properly as a gutter layer, and when it exceeds 5 wt%, there is a problem in that transmittance is significantly reduced.

In one embodiment of the present specification, the composition for forming a gutter layer further comprises an aliphatic hydrocarbon solvent.

In an exemplary embodiment of the present specification, the aliphatic hydrocarbon solvent may be at least one selected from among freons, alkanes having 5 to 12 carbon atoms, and isoparaffinic 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).

In an exemplary embodiment of the present specification, the solvent of the composition for forming a gutter layer is an alkane having 5 to 12 carbon atoms, preferably hexane.

In the exemplary embodiment of the present specification, the remainder of the composition for forming a gutter layer except for PDMS may be a solvent.

In an exemplary embodiment of the present specification, the method of manufacturing the separator further includes forming a protective layer by applying a composition for forming a protective layer including polydimethylsiloxane (PDMS) on the active layer.

In an exemplary embodiment of the present specification, based on 100wt% of the composition for forming a protective layer, the content of the polydimethylsiloxane is 1wt% to 20wt%, preferably 1wt% to 10wt%, more preferably 1wt% to 5 wt%.

When the content of polydimethylsiloxane in the composition for forming a protective layer is less than 1 wt%, there is a problem of very low selectivity, and when it exceeds 20 wt%, there is a problem of very low transmittance.

In an exemplary embodiment of the present specification, the composition for forming a protective layer further comprises an aliphatic hydrocarbon solvent.

In an exemplary embodiment of the present specification, the aliphatic hydrocarbon solvent may be at least one selected from among freons, alkanes having 5 to 12 carbon atoms, and isoparaffinic 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).

In one embodiment of the present specification, the solvent of the composition for forming a protective layer is an alkane having 5 to 12 carbon atoms, preferably hexane.

In an exemplary embodiment of the present specification, the remainder except for PDMS in the composition for forming a protective layer is a solvent.

In one embodiment of the present specification, the separation membrane is manufactured according to the above-described manufacturing method, and the description of the above-described separation membrane may be cited.

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

<Production Example: Preparation of Gas Separation Membrane>

<Example 1>

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

This solution was cast to a thickness of 50 µm on a nonwoven fabric (porous support) having a thickness of 95 µm to 100 µm of a polyester material to form a support layer. Then, the cast nonwoven fabric was placed in water to prepare a porous polysulfone support layer.

In order to form a gutter layer on the support layer, a solution consisting of 1wt% of PDMS (Dow Corning's Sylgard 184, hereinafter the same) and 99wt% of hexane was applied on the support layer and then dried in an oven at 95°C for 5 minutes, 10 A gutter layer with a thickness of nm was formed.

After that, a solution for forming an active layer consisting of 0.5wt% of acetylated methyl cellulose (Lotte Fine Chemical) and 99.5wt% of nitromethane on the gutter layer was applied on the gutter layer, and then dried in an oven at 60°C for 5 minutes. , an active layer with a thickness of 1,000 nm was formed.

In order to form a protective layer on the active layer, a solution consisting of 1wt% of PDMS (Sylgard 184, Dow Corning, hereinafter the same) and 99wt% of hexane is applied on the support layer, and then dried in an oven at 95°C for 5 minutes, and 500 nm A thick protective layer was formed.

Through this, a flat membrane gas separation membrane was manufactured, and 25 to 30 gas separation membranes of the manufactured flat membrane were wound around an inner core tube and rolled, and then the surface was coated with fiber reinforced plastic. The final winding was performed to prepare a gas separation membrane module.

<Example 2>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Example 1, except that the concentration of acetylated methyl cellulose in Example 1 was changed to 1.0 wt%.

<Example 3>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Example 1, except that the concentration of acetylated methyl cellulose in Example 1 was changed to 1.5 wt%.

<Comparative Example 1>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Example 1, except that the active layer and the protective layer were not formed in Example 1.

<Comparative Example 2>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Example 1, except that the concentration of acetylated methyl cellulose in Example 1 was changed to 0.1 wt%.

<Comparative Example 3>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Example 1, except that the concentration of acetylated methyl cellulose in Example 1 was changed to 0.3 wt%.

<Comparative Example 4>

A gas separation membrane and a gas separation membrane module were prepared in the same manner as in Example 1, except that a solution consisting of 0.5wt% of sodium carboxymethyl cellulose and 99.5wt% of water was used as the solution for forming the active layer in Example 1 prepared.

<Comparative Example 5>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Comparative Example 4, except that the concentration of sodium carboxymethyl cellulose in Comparative Example 4 was changed to 1.0 wt%.

<Comparative Example 6>

A gas separation membrane and a gas separation membrane module were manufactured in the same manner as in Comparative Example 4, except that the concentration of sodium carboxymethyl cellulose was changed to 1.5 wt% in Comparative Example 4.

<Experimental Example 1: Measurement of T value>

For the surfaces of the gas separation membranes prepared in Examples 1 to 3 and Comparative Examples 1 to 6, the peak intensity of the C = O bond (at 1754 cm ^-1 ) using the ATR measurement method of a Fourier transform infrared spectrometer (FT-IR). Peak intensity) and the peak intensity of the S=O bond (peak intensity at 1175 cm ^-1 ) were measured, and the T value was calculated by substituting it in [Equation 1]. The results are shown in Table 1 below.

Cellulose type in the active layer Cellulose content in the active layer
(wt%) 1754 cm ^-1
(C=O) 1175 cm ^-1
(S=O) T value Example 1 AMC 0.5 0.0486698 0.0681542 0.7141 Example 2 AMC 1.0 0.0909321 0.0726477 1.2517 Example 3 AMC 1.5 0.112376 0.0797386 1.4093 Comparative Example 1 - - 0.00147958 0.0423896 0.0349 Comparative Example 2 AMC 0.1 0.026605 0.0683604 0.3892 Comparative Example 3 AMC 0.3 0.0299007 0.0615722 0.4856 Comparative Example 4 SCMC 0.5 0.007655 0.017304 0.4424 Comparative Example 5 SCMC 1.0 0.000603 0.0075 0.0804 Comparative Example 6 SCMC 1.5 0.010846 0.019665 0.5515

Through the results in Table 1, the T values of Examples 1 to 3 according to an exemplary embodiment of the present specification are all 0.6 or more, while the concentration of AMC is less than 0.5 wt%, or Comparative Examples 1 to 6 using other cellulose instead of AMC It can be seen that all T values of are less than 0.6.

<Experimental Example 2: Evaluation of carbon dioxide gas permeability and selectivity>

After fastening the gas separation membrane modules prepared in the Examples and Comparative Examples to the gas separation membrane cell (area 14cm ² ) at room temperature (25° C.), a constant pressure (50 psi) using a pressure regulator on the top of the cell , 80 psi, 100 psi, and 200 psi) of carbon dioxide gas was injected to induce gas permeation due to the pressure difference between the upper portion of the membrane (in the direction of the protective layer) and the lower portion (in the direction of the porous support layer).

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 carbon dioxide gas permeability of the gas separation membrane was evaluated in consideration of the stabilization time (> 1 hour), which is described in Table 2 below. did.

T value permeability Selectivity (CO ₂ /CH ₄ ) P _CO2 (GPU) P _CH4 (GPU) Example 1 0.7141 125 7.7 16.3 Example 2 1.2517 62 4.2 14.6 Example 3 1.4093 48 2.1 22.7 Comparative Example 1 0.0349 156000 216000 0.72 Comparative Example 2 0.3892 187 137 1.4 Comparative Example 3 0.4856 132 95 1.4 Comparative Example 4 0.4424 96485 101564 0.95 Comparative Example 5 0.0804 6886 12695 0.54 Comparative Example 6 0.5515 1148 1757 0.65

The CO ₂ /CH ₄ selectivity refers to the ratio of the permeability of the carbon dioxide gas to the permeability of the methane gas. Referring to the results of Table 2, the gas separation membranes of Examples 1 to 3 according to an exemplary embodiment of the present specification It can be seen that the selectivity of carbon dioxide to methane is 14 or more, and at most 20 or more, indicating a high value.

Specifically, in Comparative Examples 1 and 4 to 6 in which the active layer was not formed or other cellulosic materials in which the peak strength of C=O bonds other than AMC were used to form the active layer, the CO ₂ /CH ₄ selectivity was It is very low below 1, and even when AMC is used, when less than 0.5 wt% is used as in Comparative Examples 2 and 3, it can be confirmed that the CO ₂ /CH ₄ selectivity is less than 1/10 of that of Example.

On the other hand, when the T value is as high as 1.4 or more among the Examples, it can be confirmed that a high CO ₂ /CH ₄ selectivity of 20 or more can be obtained.

In conclusion, the gas separation membrane according to an exemplary embodiment of the present specification is excellent in selectively separating carbon dioxide.

10: porous substrate
20: porous support layer
30: gutter layer
40: active layer
50: protective layer

Claims (15)

a porous support layer comprising at least one polymer selected from polysulfone, polyethersulfone, polyetherethersulfone, and polyphenylsulfone;
a gutter layer formed on the porous support layer and including a silicon-based compound; and
An active layer formed on the gutter layer and comprising Acetylated Methyl Cellulose (AMC)
As a separation membrane comprising:
A separator having a T value of 0.6 or more on the surface of the separator:
[Equation 1]
T=(peak intensity of C=O bond)/(peak intensity of S=O bond)
In Equation 1, the peak intensity means the absorption intensity measured by a Fourier transform infrared spectrometer (FT-IR),
The C=O bond is a bond present in the active layer, and the S=O bond is a bond present in the porous support layer. The method according to claim 1,
The silicone-based compound is one of polydimethylsiloxane (PDMS), poly(1-trimethylsilyl-1-propyne) (Poly(1-trimethylsilyl-1-propyne), PTMSP) and polyoctylmethylsiloxane (POMS). Separation membrane that is one or more selected. The method according to claim 1,
A separation membrane formed on the active layer and further comprising a protective layer containing polydimethylsiloxane (PDMS, polydimethylsiloxane). 4. The method of claim 3,
carbon dioxide single gas at a pressure of 14 psi to 600 psi; Alternatively, a separation membrane having a carbon dioxide gas permeability of 30GPU to 130GPU measured by permeating a mixed gas containing carbon dioxide and methane from the protective layer toward the porous support layer. 4. The method of claim 3,
methane single gas at a pressure of 14 psi to 600 psi; Alternatively, a separation membrane having a methane gas permeability of 1GPU to 15GPU measured by permeating a mixed gas containing carbon dioxide and methane from the protective layer to the porous support layer. The method according to claim 1,
The separation membrane has a selectivity of carbon dioxide gas to methane gas of 10 to 30. The method according to claim 1,
The separation membrane is a gas separation membrane. A separation membrane module comprising one or more separation membranes according to any one of claims 1 to 7. forming a porous support layer by applying a solution containing at least one polymer selected from among polysulfone, polyethersulfone, polyetherethersulfone and polyphenylsulfone on a porous substrate;
forming a gutter layer by applying a composition for forming a gutter layer including a silicone-based compound on the porous support layer; and
Forming an active layer by applying a composition for forming an active layer comprising acetylated methyl cellulose (AMC, Acetylated Methyl Cellulose) on the gutter layer,
Based on 100wt% of the composition for forming the active layer, the content of the acetylated methyl cellulose is 0.5wt% to 5wt%. 10. The method of claim 9,
The silicone-based compound is one of polydimethylsiloxane (PDMS), poly(1-trimethylsilyl-1-propyne) (Poly(1-trimethylsilyl-1-propyne), PTMSP) and polyoctylmethylsiloxane (POMS). A method for producing a separation membrane that is one or more selected. 10. The method of claim 9,
The composition for forming the active layer is a method of manufacturing a separation membrane that further comprises nitromethane as a solvent. 10. The method of claim 9,
Based on 100 wt% of the composition for forming a gutter layer, the content of the silicone-based compound is 0.5 wt% to 5 wt%. 10. The method of claim 9,
The method of manufacturing a separation membrane further comprising the step of forming a protective layer by applying a composition for forming a protective layer comprising polydimethylsiloxane (PDMS, polydimethylsiloxane) on the active layer. A separation membrane prepared according to the method of any one of claims 9 to 13. 15. The method of claim 14,
A separator having a T value of 0.6 or more on the surface of the separator:
[Equation 1]
T=(peak intensity of C=O bond)/(peak intensity of S=O bond)
In Equation 1, the peak intensity means the absorption intensity measured by a Fourier transform infrared spectrometer (FT-IR),
The C=O bond is a bond present in the active layer, and the S=O bond is a bond present in the porous support layer.

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