KR20180097311A - CO2―tolerant dual―phase hollow fiber membrane for oxygen separation and preparation method thereof - Google Patents

Abstract

The present invention relates to a carbon dioxide-tolerant dual-phase hollow fiber membrane for oxygen separation and a preparation method thereof, wherein the hollow fiber membrane has a composition represented by chemical formula 1: Ce_xSm_(1-x)O_(2-δ)-Sm_ySr_(1-y)Cu_zFe_(1-z)O_(3-δ). Therefore, the carbon dioxide-tolerant dual-phase hollow fiber membrane exhibits stable oxygen permeability even when high concentration carbon dioxide is used as sweep gas, and thus can be usefully used for oxygen separation in a carbon dioxide atmosphere such as a pure oxygen combustion capture process. In the chemical formula 1, 0 <= x <= 1, 0 <= y <= 1, and 0 <= z <= 1.

Description

TECHNICAL FIELD [0001] The present invention relates to a dual-phase hollow fiber membrane for oxygen separation having carbon dioxide resistance and a method for producing the dual-

The present invention relates to a dual-phase hollow fiber membrane for oxygen separation having a carbon dioxide resistance which can be used for oxygen separation in a carbon dioxide atmosphere such as a pure oxygen combustion collecting process, which exhibits a stable oxygen permeability even when a high concentration of carbon dioxide is used as a sweep gas, And a manufacturing method thereof.

Oxygen combustion capture technology, one of carbon dioxide capture and storage technologies, is a process that uses pure oxygen instead of air to burn and collects high concentration of carbon dioxide in the exhaust gas after combustion.

The pure oxygen combustion capture technique has the advantage of increasing the combustion efficiency because it uses pure oxygen. When the water is removed through the condenser after the combustion exhaust gas composed mostly of water and carbon dioxide, it collects the high concentration of carbon dioxide, This technology is expected to have a gas reduction effect.

On the other hand, oxygen production processes include deep-cooling fractionation distillation, pressure swing adsorption (PSA), and polymer membrane separation. The commercialized deep sea cooling method and the PSA require a lot of investment and operating costs due to the characteristics of the equipment. In the polymer membrane method, since the oxygen selectivity is not high, it is difficult to block the flow of nitrogen.

On the other hand, the oxygen separation process using the ion conductive ceramic membrane, which is being studied recently, is expected to replace the existing process with high efficiency and low cost as compared with the existing oxygen production process.

The ion conductive ceramic separator has a disadvantage that the operating temperature must be high. However, when the ion conductive ceramic separator is applied to a pure oxygen combustion process, it is possible to easily maintain the temperature of 850 DEG C or more suitable for the operating conditions of the separator effective.

As the material of the ion conductive ceramic separator, a perovskite type oxide is most widely used. Perovskite oxides of various compositions such as La _x Sr _1-x Co _y Fe _1-y O _3-δ (LSCF) and Ba _x Sr _1-x CoFe _1-y O _3-δ (BSCF) And the compositions including alkaline earth metals such as Sr and Ba showed excellent oxygen permeability.

However, such a separation membrane containing an alkaline earth metal has unstable characteristics in a CO ₂ atmosphere, and a carbon compound is deposited on the separation membrane surface, thereby reducing the oxygen permeability.

Since the oxyfuel combustion process uses carbon dioxide as a sweep gas after combustion, the resistance of the separation membrane to carbon dioxide is essential.

Accordingly, there is a demand for a new separation membrane (hollow fiber membrane) capable of effectively separating oxygen in a carbon dioxide atmosphere while improving the resistance to carbon dioxide.

Korean Patent No. 1496751 Korean Patent No. 1288530

It is an object of the present invention to provide a dual-phase hollow fiber membrane which can be used for oxygen separation in a carbon dioxide atmosphere such as a pure oxygen combustion collecting process, which shows a stable oxygen permeability even when a high concentration of carbon dioxide is used as a sweep gas.

It is another object of the present invention to provide a method for producing the dual-phase hollow fiber membrane.

It is still another object of the present invention to provide a membrane module including the dual-phase hollow fiber membrane.

It is still another object of the present invention to provide a hollow fiber membrane contact apparatus including the membrane module.

To achieve the above object, the dual phase hollow fiber membrane for oxygen separation according to the present invention having a carbon dioxide resistance has a composition represented by the following Chemical Formula 1;

[Chemical Formula 1]

Ce _x Sm _{1 - x} O _{2 -? -} Sm _y Sr _{1 - y} Cu _z Fe _{1 - z} O _{3 -?}

1? 0? Y? 1 and 0? Z? 1 in the above formula (1).

The Ce _x Sm _{1 -x} O _{2 -δ} and the Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _{3 -δ} may be mixed in a weight ratio of 5: 5 to 9: 1.

The oxygen-separating dual-phase hollow fiber membrane having carbon dioxide resistance may be in the form of a toroidal column having an inside diameter of 0.3 to 0.9 mm and an outside diameter of 1.1 to 1.7 mm.

According to another aspect of the present invention, there is provided a method for producing a dual phase hollow fiber membrane for oxygen separation having oxygen-resistant carbon dioxide, comprising the steps of: (A) preparing a polymer solution by mixing a polymer binder and an organic solvent; (B) Ce _x Sm _1-x O _2-δ composition (0 ≦ _x ≦ ₁ ) and a composition Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3-δ (0.1≤y≤0.5 and 0.1 Lt; / = z &lt; / = 0.3) to prepare a mixed powder; (C) adding the mixed powder and the plasticizer to the polymer solution to prepare a dope solution; (D) feeding and discharging the dope solution with a double spinning nozzle together with an internal coagulant to form a hollow fiber; And (E) contacting the hollow fiber with an external coagulant, passing through a phase transition process, and washing, drying and sintering the hollow fiber to obtain a hollow fiber membrane.

In the step (A), the polymer binder may be at least one selected from the group consisting of polysulfone, polyethersulfone, polyetherimide, polyamide, and polyacrylonitrile.

In the step (A), the organic solvent may be at least one selected from the group consisting of N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc) and dimethylsulfoxide (DMSO).

In the step (B), a powder having a composition of Ce _x Sm _{1 -x} O _2-δ (0 ≦ _x ≦ ₁ ) and a composition Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3-δ (0.1 ≦ _y ≦ 0.5 and 0.1? Z? 0.3) may be mixed in a weight ratio of 5: 5 to 9: 1.

In the step (B), the mixed powder may be contained in an amount of 50 to 69% by weight.

In the step (C), the plasticizer may be polyvinylpyrrolidone or polyvinyl alcohol.

In the step (D), the internal coagulant and the external coagulant may be water.

The hollow fiber phase transformed in the step (E) is dried at a temperature of T1, heated at a rate of 0.5 to 2 ° C / min at T1, sintered at a temperature of T2,

The temperature of T1 may be 100-150 占 폚 and the temperature of T2 may be 1100-1200 占 폚.

According to another aspect of the present invention, a membrane module of the present invention may include a dual-phase hollow fiber membrane for oxygen separation having the carbon dioxide resistance.

According to another aspect of the present invention, a hollow fiber membrane contactor may include the membrane module.

The dual-phase hollow fiber membrane for oxygen separation having the carbon dioxide resistance of the present invention shows stable oxygen permeability even when high concentration of carbon dioxide is used as a sweep gas and can be usefully used for oxygen separation in a carbon dioxide atmosphere such as a pure oxygen combustion collecting process.

Further, by applying the membrane module including the dual-phase hollow fiber membrane of the present invention to an air separation unit, it is possible to effectively separate oxygen in a carbon dioxide atmosphere.

FIG. 1B is a SEM photograph of the cross section of the hollow fiber membrane produced according to Example 1, FIG. 1C is a cross-sectional view of the hollow fiber membrane according to Example 1 1 is an SEM photograph of the inner surface of the hollow fiber membrane manufactured according to Example 1. FIG. 1D is a SEM image of the outer surface of the hollow fiber membrane produced according to Example 1. FIG.
FIG. 2 is a graph showing the XRD (Rigaku Dmax-2500pc, USA) measurement of the hollow fiber membrane produced according to Example 1. FIG.
3 is a schematic diagram of a hollow fiber membrane oxygen permeation experiment apparatus.
4 is a graph showing the oxygen permeability of the hollow fiber membrane of Example 1 according to the temperature at a simulated air flow of 100 ml / min and a sweep gas (He or CO ₂ ) of 50 ml / min.
5 is a graph showing the results of oxygen permeability according to the sweep gas composition.
6 is a graph showing oxygen permeability according to CO ₂ flow rate at a set temperature of 950 ° C.
7 is a graph showing a long-term transmission of a sweep gas for 7 days using the hollow fiber membrane produced according to Example 1. FIG.
FIG. 8A is a photograph of the inner surface of the hollow fiber membrane produced according to Example 1 after the oxygen permeation test, and FIG. 8B is a photograph of the outer surface of the hollow fiber membrane prepared according to Example 1 after the oxygen permeation test by SEM It's a picture.
FIG. 9 is a photograph of the hollow fiber membrane prepared according to Example 1 after the oxygen permeation test by EDX.

The present invention relates to a dual-phase hollow fiber membrane for oxygen separation having a carbon dioxide resistance which can be used for oxygen separation in a carbon dioxide atmosphere such as a pure oxygen combustion collecting process, which exhibits a stable oxygen permeability even when a high concentration of carbon dioxide is used as a sweep gas, And a manufacturing method thereof.

The sweep gas refers to a gas that continuously pushes the permeated gas to maintain the oxygen partial pressure difference.

Hereinafter, the present invention will be described in detail.

The dual-phase hollow fiber membrane for oxygen separation having the carbon dioxide resistance of the present invention has a composition represented by the following formula (1).

[Chemical Formula 1]

Ce _x Sm _{1 - x} O _{2 -? -} Sm _y Sr _{1 - y} Cu _z Fe _{1 - z} O _{3 -?}

X? 1, 0? Y? 1 and 0? Z? 1 in Formula 1, preferably 0.7? X? 0.9, 0.1? Y? 0.5 and 0.1? Z? 0.3, more preferably x = 0.8, y = 0.3, and z = 0.2. If the number of x, y, and z is out of the above range, resistance to carbon dioxide may be reduced. The oxygen separator has oxygen vacancy in order to have the separation performance, and the hollow fiber membrane constituting the present invention also has an oxygen vacancy, which is denoted by?.

The Ce _x Sm _1-x O _2-δ and the Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _{3 -δ} are present in a weight ratio of 5: 5 to 9: 1, preferably 6: 4 to 7: 3 Mixed in a weight ratio; When the weight ratio is out of the above range, the carbon dioxide resistance and the oxygen permeability may be reduced.

The dual-phase hollow fiber membrane for oxygen separation according to the present invention having a toroidal columnar shape, that is, a shape having a center of a column penetrated, has an inner diameter of 0.3 to 0.9 mm, preferably 0.7 to 0.9 mm; And an outer diameter of 1.1 to 1.7 mm, preferably 1.3 to 1.5 mm. When the shape of the hollow fiber membrane is a toroidal column shape and the outer diameter and inner diameter satisfy the above range, more stable oxygen permeability is shown and oxygen can be more easily separated from the carbon dioxide zone.

The present invention also provides a method for producing a dual phase hollow fiber membrane for oxygen separation having carbon dioxide resistance.

The present invention provides a method for producing a dual phase hollow fiber membrane for oxygen separation having carbon dioxide resistance, comprising the steps of: (A) preparing a polymer solution by mixing a polymer binder and an organic solvent; (B) Ce _x Sm _1-x O _2-δ composition (0 ≦ _x ≦ ₁ ) and a composition Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3-δ (0.1≤y≤0.5 and 0.1 Lt; / = z &lt; / = 0.3) to prepare a mixed powder; (C) adding the mixed powder and the plasticizer to the polymer solution to prepare a dope solution; (D) feeding and discharging the dope solution with a double spinning nozzle together with an internal coagulant to form a hollow fiber; And (E) contacting the hollow fiber with an external coagulant, passing through a phase transition process, and washing, drying and sintering the fiber to obtain a hollow fiber membrane.

First, in the step (A), a polymer solution is prepared by mixing a polymer binder and an organic solvent.

The polymer binder binds Ce _x Sm _1-x O _2-δ powder particles and Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _{3 -δ} powder particles, and specifically includes polysulfone, polyether sulfone, Polyetherimide, polyamide, and polyacrylonitrile. Of these, polyetherimide is preferably used.

The polymer binder is contained in the total dope solution in an amount of 5 to 15% by weight, preferably 7 to 10% by weight. When the content of the polymeric binder is less than the lower limit value, the Ce _x Sm _1-x O _2-δ powder particles and the Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _{3 -δ} powder particles can not be combined, , The content of other substances may be reduced and the desired effect may not be obtained.

The organic solvent may dissolve the polymer binder, and may be polar aprotic solvent such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc ), And dimethylsulfoxide (DMSO). Among these, N-methylpyrrolidone (NMP) is preferably used.

The organic solvent is contained in the total dope solution in an amount of 25 to 40% by weight, preferably 30 to 35% by weight.

Next, in the step (B), a composition having a composition of Ce _x Sm _{1 -x} O ₂ -δ (0 _{? X ?} 1) and a composition Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3- ? Y? 0.5 and 0.1? Z? 0.3) are mixed to prepare a mixed powder.

The mixed powder is contained in the total dope solution in an amount of 50 to 69% by weight, preferably 55 to 65% by weight, more preferably 60 to 62% by weight. When the content of the mixed powder is less than the lower limit value, the carbon dioxide resistance of the hollow fiber membrane is lowered and stable oxygen permeability may not be exhibited. When the content exceeds the upper limit value, oxygen is easily separated from the carbon dioxide I can not.

Next, in the step (C), the mixed powder and the plasticizer are added to the polymer solution to prepare a dope solution.

The plasticizer is a material for increasing thermoplasticity, and examples thereof include polyvinyl pyrrolidone and polyvinyl alcohol.

The plasticizer is contained in the total dope solution in an amount of 0.1 to 5% by weight, preferably 0.5 to 1% by weight. When the content of the plasticizer is out of the above range, the molding process may not be easy.

 Next, in the step (D), the dope solution is supplied and discharged with a double spinning nozzle together with an internal coagulant to form a hollow fiber.

The dope solution is supplied to a double spinning nozzle having an outer diameter and then ejected to form a hollow fiber.

At this time, the internal coagulant is water, preferably distilled water.

Next, in the step (E), the hollow fiber is contacted with an external coagulant and subjected to phase transformation, followed by washing, drying and sintering to obtain a hollow fiber membrane.

The use of water as the internal coagulant and external coagulant facilitates the asymmetric porous membrane by interchanging the solvent-non-solvent during the formation of the hollow fiber and the phase transition.

The phase-transformed hollow fiber is dried in an oven at a T1 temperature of 100 to 150 ° C and then sintered at a temperature of 1100 to 1200 ° C at a temperature elevation rate of 0.5 to 2 ° C / min at T1.

When the drying temperature is lower than the lower limit, the time required to remove moisture increases, and when the drying temperature is higher than the upper limit, denaturation of the polymer may occur. If the sintering temperature is lower than the lower limit value, the strength of the hollow fiber membrane may be lowered. If the sintering temperature is higher than the upper limit value, the oxygen permeability may be decreased and the energy cost may be further increased. It is possible to obtain a hollow fiber membrane having an inner diameter in the form of a toroidal column of 0.3 to 0.9 mm and an outer diameter of 1.1 to 1.7 mm by raising the temperature at the heating rate.

In addition, the present invention provides a membrane module including a dual-phase hollow fiber membrane for oxygen separation having carbon dioxide resistance. By applying the membrane module to a hollow fiber membrane contact apparatus, oxygen can be separated in a carbon dioxide atmosphere.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example 1. Ce _0.8 Sm _0.2 O ₂ -Sm _0.3 Sr _0.7 Cu _z Fe _0.8 O _3-delta Preparation of Hollow Fiber Membrane Having Composition

Polyetherimide (PEI, Aldrich, USA) and N-methylpyrrolidone (NMP 99.5%, Samchun, Korea) as a polymer binder were mixed at a rate of 7.78 wt% and 31.12 wt%, respectively, Followed by stirring for 24 hours to prepare a polymer solution. _{Ce 0.8 Sm 0.2 O 2-δ} (SDC) powder and _{Sm 0.3 Sr 0.7 Cu z Fe 0.8} O 3-δ (SSCF3728) Powder 6: After preparing a mixed powder by mixing in a weight ratio of 4 SDC-SSCF3728 mixed powder 60.52 And 0.58 wt% of polyvinylpyrrolidone (PVP, average mol wt 40,000, Aldrich, USA) were added to the polymer solution and stirred at a rate of 150 rpm at room temperature for 24 hours to prepare a Dope solution Respectively.

After stirring was completed, the solution was allowed to stand for 12 hours (overnight) to remove residual bubbles in the dope solution. Then, the dope solution was immersed in a dope solution reservoir and supplied with nitrogen at a gauge pressure of 0.5 bar. The dope solution is supplied to the double spinning nozzle by using the pressure, the dope solution is discharged through the outer nozzle of the double spinning nozzle, the distilled water which is an internal coagulating agent is injected into the spinning nozzle through a syringe pump At a flow rate of 10 ml / min, a phase transition starts between the internal coagulant and the dope solution to form a hollow fiber. The formed hollow fiber is in phase contact with tap water (tap water) which is an external coagulant for 24 hours. The phase-transformed hollow fiber was dried in an oven at 120 ° C. for 12 hours and then sintered at a heating rate of 1 ° C./min at 1150 ° C. to obtain a hollow fiber membrane.

At this time, the air gap was maintained at 2 cm, and a nozzle (Spinneret, Sepratek, Korea) having outer and inner diameters of 3.0 mm (outer diameter) and 1.2 mm (inner diameter) was used.

<Test Example>

Test Example 1. SEM measurement

FIG. 1B is a SEM photograph of the cross section of the hollow fiber membrane produced according to Example 1, FIG. 1C is a cross-sectional view of the hollow fiber membrane according to Example 1 1D is a SEM image of the outer surface (exposed surface) of the hollow fiber membrane produced according to Example 1, and FIG. 1D is a photograph of the inner surface of the hollow fiber membrane manufactured according to Example 1 It is a photograph.

The above SEM (FE-SEM, S-4800, HITACHI, Japan) analysis is for checking the thickness and structure of the hollow fiber membrane and the compactness of the hollow fiber membrane.

As shown in FIGS. 1A to 1D, it was confirmed that the hollow fiber membrane was in the form of a toroidal column after sintering, and the outer diameter and the inner diameter were 1.367 mm and 0.7229 mm, respectively. Further, it was confirmed that the outer and inner surfaces of the hollow fiber membrane were all dense structures having grain boundaries.

Test Example 2. X-ray diffractometer (XRD) measurement

FIG. 2 is a graph showing the XRD (Rigaku Dmax-2500pc, USA) measurement of the hollow fiber membrane produced according to Example 1. FIG.

As shown in FIG. 2, the hollow fiber membrane of Example 1 was found to have a Ce _0.8 Sm _0.2 O ₂ -δ (SDC, fluorite phase) phase and a Sm _0.3 Sr _0.7 Cu _z Fe _0.8 O _{3 -δ} (SSCF3728, perovskite phase).

The X-ray was measured with a CuKα line of 40 kV and 200 mA, and the scanning range (2θ) was measured at 20 ^{° to} 80 ^° with an interval of 0.02.

Test Example 3. Oxygen permeation experiment

3 is a schematic diagram of a hollow fiber membrane oxygen permeation experiment apparatus.

As shown in FIG. 3, oxygen and nitrogen for use as simulated air are supplied to the mass flow meter at a constant pressure in the gas cylinder. And an oxygen concentration of 21% by volume and a flow rate of 100 ml / min. Similarly, He or CO ₂ is supplied as a sweep gas, and the gas permeated through the sweep gas line enters a gas chromatograph (Agilent, Gas chromatography 7890A, USA) and detects gas components through a TCD (Thermal conductivity detector). The pressure of the sweep gas line, the supply of the permeation experiment device, and the pressure sensor (A-10, WIKA, Korea) are output to the pressure indicator.

The hollow fiber membrane of Example 1 was placed in a quartz tube (10.5 x 12.75 x 300 mm, HANJIN QUARTZ, Korea) equipped with a vacuum fitting (Ultra Torr fitting, Swagelok, USA) Hylok, Korea) and then sealed with a ceramic bond (Aron ceramic D-5, TOAGOSEI CHEMICAL, Japan). The sealed hollow fiber membrane was placed in an electric furnace (80 × 240 × 100 mm, DAIHAN Scientific, Korea) and heated to 950 ° C. at a heating rate of 1 ° C./min. In the compactness test, the components of the permeated gas were analyzed by GC while nitrogen and helium were supplied at 100 and 10 ml / min, respectively, as feed and sweep gas. As a result of the analysis, when the nitrogen fraction of the permeated gas was measured to be less than 0.5%, it was judged that there was no leak in the oxygen permeation test apparatus and the sealing portion of the hollow fiber membrane.

4 is a graph showing the oxygen permeability of the hollow fiber membrane of Example 1 according to the temperature at a simulated air flow of 100 ml / min and a sweep gas (He or CO ₂ ) of 50 ml / min.

The oxygen permeability and the oxygen permeability reduction rate were calculated by the following equations (1) and (2), respectively.

[Equation 1]

&Quot; (2) &quot;

,

,

,

,

,

,

는 각각 산소 투과도, 스윕가스의 유량, 투과 기체 중 산소의 농도, 중공사막의 유효 투과 면적, 산소 투과도 감소율, He 스윕조건 또는 CO₂ 스윕조건에서 중공사막의 산소 투과도를 나타낸다. In the above equations (1) and (2)

,

,

,

,

,

,

Represent the oxygen permeability of the hollow fiber membrane in the oxygen permeability, the flow rate of the sweep gas, the oxygen concentration in the permeable gas, the effective permeable area of the hollow fiber membrane, the oxygen permeability reduction ratio, the He sweep condition or the CO ₂ sweep condition.

As shown in FIG. 4, the oxygen permeability tended to increase with increasing temperature. At 1000 ° C in the He sweep condition, the maximum value was 1.03 ml / min cm ^{2. In} the CO ₂ sweep condition, 25.4 %, Which is 0.77 ml / min ㅇ cm ² .

Also, the change of oxygen permeability was examined according to the sweep gas composition at a set temperature of 950 ° C and 900 ° C while feeding and sweeping gas were supplied at 100 ml / min and 50 ml / min, respectively.

5 is a graph showing the results of oxygen permeability according to the sweep gas composition.

As shown in FIG. 5, when the permeability was reduced in the CO ₂ sweep condition and then the He sweep condition was changed again, the permeability was restored to the previous permeability. The reason for this result is that CO ₂ molecules are adsorbed on the surface of hollow fiber membrane in the CO ₂ sweep condition to form carbonate, and if it is changed to He sweep condition again, the oxygen is recovered again after the decomposition of carbonate.

6 is a graph showing oxygen permeability according to CO ₂ flow rate at a set temperature of 950 ° C. This is to understand the concentration of oxygen in the permeated gas.

As shown in FIG. 6, as the sweep gas flow rate increases, the oxygen permeability also increases, but at 20 ml / min or more, the increase width is very low and only the oxygen concentration in the permeated gas is lowered.

When the sweep gas was supplied at a flow rate of 5 ml / min, the oxygen concentration of 10.4% by volume was obtained, but the permeability was 0.23 ml / min · cm ² due to the reduction of the difference in the oxygen partial pressure. In actual oxy-fuel combustion process, oxygen must be injected at a concentration of 30% by volume or more.

7 is a graph showing a long-term transmission of a sweep gas for 7 days using the hollow fiber membrane produced according to Example 1. FIG.

As shown in FIG. 7, the rate of decrease in oxygen permeability was measured under a CO ₂ sweep condition, and it was confirmed that the oxygen permeability was kept constant after the decrease in oxygen permeability.

It was confirmed that the oxygen permeability was decreased but kept constant under the CO ₂ sweep condition. Therefore, it was confirmed that the formation of carbonate on the surface of the hollow fiber membrane resulted in a decrease in the oxygen permeability, but the continuous performance of the hollow fiber membrane itself was not deteriorated.

The rate of decrease of oxygen permeability showed a tendency to increase with decreasing temperature. It is considered that the equilibrium point shifted in the direction of forming carbonate rather than carbonate decomposition at lower temperature because carbonate decomposes to around 900 ℃.

Test Example 4. SEM Measurement after Oxygen Permeation Test

FIG. 8A is a photograph of the inner surface (inner surface of the through hole) of the hollow fiber membrane produced according to Example 1 after the oxygen permeation test, and FIG. 8B is a photograph of the hollow fiber membrane prepared according to Example 1 after the oxygen permeation experiment. It is the SEM image of the outer surface (exposed surface).

FIG. 9 is a photograph of the hollow fiber membrane prepared according to Example 1 after the oxygen permeation test by EDX.

The purpose of the SEM and EDX analysis was to examine the changes in the surface of the hollow fiber membrane before and after the oxygen permeation experiment and to confirm the formation of carbonate through elemental mapping when impurities were formed.

As shown in FIGS. 8A and 8B, the cross section of the hollow fiber membrane was observed, and it was confirmed that impurities were deposited on the inner surface. Specifically, the inner surface and the outer surface of the hollow fiber membrane before and after the oxygen permeation experiment were compared, and it was confirmed that tooth-like crystals were formed on the inner surface.

Elemental mapping of the Ce, Sr, and C elements to the inner surface of the hollow fiber membrane of Example 1 was performed to observe the SDC corresponding to the fluorite phase and the SSCF3728 carbonate corresponding to the perovskite phase, respectively.

As shown in FIG. 9, according to the result of elemental mapping, element C was detected on the perovskite phase including Sr. Therefore, fluorite phase of Ce is included, only SSCF3728 including Sr was not reacted with CO ₂ appears to be a carbonate is produced by reacting with CO _2.

Claims (15)

A dual phase hollow fiber membrane for oxygen separation having a composition of the following formula (1) having carbon dioxide resistance;
[Chemical Formula 1]
_{Ce x Sm 1 - x O 2} -δ -Sm y Sr 1 - y Cu z Fe 1 - z O 3 -δ
1? 0? Y? 1 and 0? Z? 1 in the above formula (1). The dual-phase hollow fiber membrane for oxygen separation according to claim 1, wherein 0.7? X? 0.9, 0.1? Y? 0.5 and 0.1? Z? 0.3 in the formula (1). The method according to claim 1, wherein Ce _x Sm _1-x O _2-δ and Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3-δ are mixed in a weight ratio of 5: 5 to 9: 1 A dual-phase hollow fiber membrane for oxygen separation having carbon dioxide resistance. The dual-phase hollow fiber membrane for oxygen separation according to claim 1, wherein the oxygen-separating dual-phase hollow fiber membrane has a toroidal columnar shape with an inner diameter of 0.3 to 0.9 mm and an outer diameter of 1.1 to 1.7 mm. Dual-phase hollow fiber desert. (A) mixing a polymer binder and an organic solvent to prepare a polymer solution;
_{(B) Ce x Sm 1 -} x O 2 -δ powder having a composition (0≤x≤1) and _{Sm y Sr 1 - y Cu z} Fe 1 - z O 3 -δ composition (0.1≤y≤0.5 and 0.1 Lt; / = z &lt; / = 0.3) to prepare a mixed powder;
(C) adding the mixed powder and the plasticizer to the polymer solution to prepare a dope solution;
(D) feeding and discharging the dope solution with a double spinning nozzle together with an internal coagulant to form a hollow fiber; And
(E) a step of contacting the hollow fiber with an external coagulant to obtain a hollow fiber membrane by washing, drying and sintering after a phase transition process, thereby producing a dual-phase hollow fiber membrane for oxygen separation having oxygen- . The method according to claim 5, wherein the polymer binder in step (A) is at least one selected from the group consisting of polysulfone, polyethersulfone, polyetherimide, polyamide, and polyacrylonitrile. Wherein the separating dual phase hollow fiber membrane is formed by a method comprising the steps of: 6. The method of claim 5, wherein the organic solvent is selected from the group consisting of N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), and dimethylsulfoxide (DMSO) Wherein the at least one oxygen-separated dual-phase hollow fiber membrane has a carbon dioxide resistance. 6. The method of claim 5, wherein in step (B), a powder having a composition Ce _x Sm _{1 -x} O _{2 -δ} (0 _{? X} ? 1) and a powder Sm _y Sr _{1 -y} Cu _z Fe _{1 -z} O _3- Wherein the powders having the composition (0.1? Y? 0.5 and 0.1? Z? 0.3) are mixed at a weight ratio of 5: 5 to 9: 1. [6] The method according to claim 5, wherein the mixed powder is contained in an amount of 50 to 69% by weight in the step (B). [6] The method of claim 5, wherein the plasticizer in step (C) is polyvinylpyrrolidone or polyvinyl alcohol. [6] The method of claim 5, wherein the internal coagulant is water in step (D). 6. The method according to claim 5, wherein the external coagulant is water in step (E). [6] The method of claim 5, wherein the hollow fiber phase transformed in step (E) is dried at a temperature of T1, heated at a rate of 0.5 to 2 [deg.] C / min at T1 and sintered at a temperature of T2,
Wherein the temperature of T1 is 100 to 150 ° C and the temperature of T2 is 1100 to 1200 ° C. 5. A membrane module comprising the dual-phase hollow fiber membrane for oxygen separation according to any one of claims 1 to 4 having a carbon dioxide tolerance. A hollow fiber membrane contact device comprising a membrane module according to claim 14.

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