KR101855417B1 - Hydrophobic ceramics hollow fiber membrane with high efficiency and strength, and preparation method thereof - Google Patents

Abstract

The present invention relates to a technique for manufacturing a hydrophobic ceramic hollow fiber membrane capable of improving the carbon dioxide absorption rate by forming a sponge structure by controlling a pore structure, and applying the same to a gas-liquid contact membrane apparatus for absorbing carbon dioxide.
According to various embodiments of the present invention, the pore structure of the hollow fiber membrane is adjusted to form a sponge structure, thereby minimizing the resistance of the gas and the hollow fiber membrane, and thereby improving the permeation amount of carbon dioxide. In addition, since the nonwettability due to the characteristic of the sponge structure having a small average pore size is increased, the movement of the gas through the pores and the mass transfer can be facilitated. Therefore, when the hollow fiber membrane is applied to a gas- And the like.

Description

Technical Field [0001] The present invention relates to a hydrophobic ceramic hollow fiber membrane for high-efficiency and high-strength characteristics, and a method for manufacturing the hollow fiber membrane.

The present invention relates to a hydrophobic ceramic hollow fiber membrane for high efficiency and high strength characteristics, and more particularly, to a hydrophobic ceramic hollow fiber membrane having a pore structure formed by a sponge structure of 95-100% The ceramic hollow fiber membrane having a single structure is characterized by being excellent in both mechanical strength, gas permeability and gas absorption characteristics, and having hydrophobicity (high contact angle, minimum infiltration pressure) against film wettability. The hydrophobic ceramic hollow fiber membrane is made of carbon dioxide Liquid contact separation membrane device for the absorption of water.

Generally, most of the energy after the industrial age was produced using thermal power generation. In the thermal power generation process, a large amount of carbon dioxide, which is a typical greenhouse gas, has been generated. As a result, the concentration of carbon dioxide in the atmosphere has rapidly increased over the last 100 years, and the average temperature of the earth has increased by about 2 ° C.

Many researches have been carried out to reduce carbon dioxide, which is the main cause of global warming. In particular, technologies for capturing and storing carbon dioxide generated in a plant area having the highest emission have been studied. Although many studies have been conducted on the development of new absorbents in the existing absorption column process, problems such as flooding and entrainment due to gas are generated, which are disadvantageous in terms of operation.

In order to solve these problems, the contact membrane process has been separated into a gas phase and a liquid phase by a contact membrane, and independently operating the gas phase and the liquid phase to treat a high flow rate gas without causing problems such as flooding and bubbling Respectively.

However, the polymer hollow fiber membrane mainly used as a contact film in the contact membrane process has a problem that it is difficult to operate for a long time due to low thermal and chemical stability problems. In addition, carbon dioxide is absorbed while moving in the order of gas phase, contact film and liquid phase, each of which is subjected to resistance to gas phase, contact film and liquid phase. Such resistance is a factor for lowering the absorption rate of carbon dioxide. However, existing contact films have limitations in improving the absorption rate of carbon dioxide due to the resistance between the gas and the contact film. (Patent Document 1)

Accordingly, in the present invention, a hollow fiber membrane having a hydrophobic surface modified by using a ceramic material having excellent thermal and chemical stability, which is a limitation of a conventional polymer membrane, is prepared, and a hollow fiber membrane The porous hollow fiber membranes were prepared by controlling the pore structure of the ceramic hollow fiber membranes.

Patent Document 1. Korean Patent No. 10-1475568

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ceramic hollow fiber membrane whose surface has been modified to have hydrophobicity by adjusting the pores of the hollow fiber membrane to a single structure of sponge structure, And to provide a hydrophobic ceramic hollow fiber membrane having a novel pore structure capable of improving the physical properties and the absorption rate of carbon dioxide, and a method for producing the same.

According to an aspect of the present invention, there is provided a hydrophobic ceramic hollow fiber membrane having a novel pore structure, wherein the pore structure is a sponge-like structure, and the sponge structure is 95 to 100% The present invention provides a hydrophobic ceramic hollow fiber membrane having a novel pore structure.

The hydrophobic ceramic hollow fiber membrane has a non-wetting property with a contact angle of 130 to 150 ° with respect to water.

The hydrophobic ceramic hollow fiber membrane is characterized by having pores having a diameter of 0.08 to 10 탆.

The present invention also relates to a process for preparing a dope solution comprising the steps of: a) mixing a alumina particle, a polymeric binder and a dispersant with triethyl phosphite to prepare a dope solution, b) feeding and discharging the dope solution with an internal coagulant, (C) contacting the hollow fiber with an external coagulant to obtain a hollow fiber membrane by drying and sintering under a phase change process, and (d) coating the sintered hollow fiber membrane with a hydrophobic material. The present invention also provides a method for producing a hydrophobic ceramic hollow fiber membrane having a structure of

The a) is characterized in that 1 to 20 parts by weight of a polymer binder, 0.1 to 5 parts by weight of a dispersant and 40 to 100 parts by weight of triethyl phosphite are mixed with 100 parts by weight of alumina particles.

The step b) is performed in an atmosphere of an extrusion pressure of 0.5 to 7 bar and an air gap of 20 cm or less.

The phase transition is performed at room temperature for 10 to 40 hours, and the drying is performed at a temperature of 100 to 200 DEG C for 10 to 40 hours.

Wherein the sintering is performed by a first sintering step of sintering at a temperature of 400 to 800 ° C, a second sintering step of sintering at a temperature of 800 to 1200 ° C after the first sintering step, Lt; RTI ID = 0.0 &gt; 1500 C < / RTI &gt; (The above temperature is the first sintering temperature &lt; the second sintering temperature &lt; the third sintering temperature)

Wherein the polymer binder is at least one selected from the group consisting of polyethersulfone, polysulfone, polyetherimide, polyamide and polyacrylonitrile.

Wherein the dispersing agent is polyvinyl pyrrolidone or polyvinyl alcohol.

The present invention also provides a membrane module comprising a hydrophobic ceramic hollow fiber membrane.

The present invention also provides a hollow fiber membrane contact apparatus including the membrane module.

According to various embodiments of the present invention, by controlling the pore structure of the ceramic hollow fiber membrane to form the sponge structure into a single structure, the resistance of the gas and the hollow fiber membrane is minimized, which is more effective in improving the permeation amount of carbon dioxide.

In addition, since the hydrophobic property of the surface of the ceramic hollow fiber membrane is improved, the movement of the gas through the pores and the mass transfer of the gas are facilitated. Therefore, when the ceramic hollow fiber membrane is applied to a gas- And exhibit remarkable effects.

1 is a schematic diagram showing a process of absorbing gaseous carbon dioxide into a liquid phase via a hollow fiber membrane.
FIG. 2 is a schematic diagram showing a process of generating a finger structure and a sponge structure of a hollow fiber membrane.
3 is an image showing the results of measurement of cross sections of the alumina hollow fiber membranes of Examples and Comparative Examples 1 to 3 by scanning electron microscopy (SEM), wherein (a) is an example, (b) 1, (c) shows Comparative Example 2, and (d) shows Comparative Example 3.
FIG. 4 is an image showing the results of measurement of the contact angle using the contact angle measuring apparatus of the hollow fiber membranes of Examples and Comparative Examples 1 to 4, wherein (a) is an example, (b) Comparative Example 2, (d) shows Comparative Example 3, and (e) shows Comparative Example 4.
FIG. 5 is a graph showing the measurement results of gas permeabilities of the hollow fiber membranes of Examples and Comparative Examples 1 to 3. FIG.
FIG. 6 is a graph showing the measurement results of the absorbed amounts of carbon dioxide in the hollow fiber membranes of Examples and Comparative Examples 1 to 3.
FIG. 7 is a schematic diagram showing an apparatus for experimenting absorption of carbon dioxide used in Examples. FIG.

Hereinafter, various aspects and various embodiments of the present invention will be described in more detail.

The present invention relates to a hydrophobic ceramic hollow fiber membrane having a novel pore structure, wherein the pore structure is a sponge-like structure, and the sponge structure is formed at 95 to 100% of a cross-sectional area of the hollow fiber membrane. Thereby providing a hydrophobic ceramic hollow fiber membrane.

Conventionally, the porous organic polymer hollow fiber membrane used in a gas-liquid contact membrane apparatus for absorbing carbon dioxide (hereinafter referred to as "gas-liquid") is deformed due to a swelling phenomenon caused by an absorbent solution, In order to overcome the problem, the material of the hollow fiber membrane was defined as alumina, which is a metal oxide based ceramic. However, since the alumina hollow fiber membrane has hydrophilicity due to the hydroxyl group (-OH) present on the surface, wetting phenomenon occurs in which the absorbent fills the pores and the permeation of the substance through the pores of the membrane is not smooth. Respectively.

In addition, the polymer hollow fiber membrane is manufactured by mixing a finger-like structure and a sponge-like structure. A finger structure having a relatively large pore size may cause an unnecessary liquid Which is a factor for lowering the amount of carbon dioxide that is absorbed and permeated.

In addition, the pore structure of the hollow fiber membrane is generated due to the interaction of the solvent and the non-solvent in the spinning process of the hollow fiber. The solvent having high miscibility and the non-solvent form a pore structure having a large finger shape, This low solvent and non-solvent leads to the development of a pore structure in the form of a sponge. When the hollow fibers are exchanged with the non-hollow fibers in the spinning process, the inner finger structure develops more than the outer finger structure.

In this regard, FIG. 2 illustrates a process in which a finger structure and a sponge structure are produced. As shown in FIG. 2, a finger-like structure has a long pore and is formed as a finger . On the other hand, the sponge-like structure means that the pore size is small and uniformly formed.

That is, in order to solve the problems of the prior art described above, the present invention has been made to modify the hydrophilic surface of the alumina hollow fiber membrane to be hydrophobic and to control the pore structure of the ceramic hollow fiber membrane to a single structure consisting of a sponge structure without a finger structure So that the absorption rate of carbon dioxide is remarkably improved.

It is preferable that the pores of the ceramic hollow fiber membrane have a diameter of 0.08 to 10 mu m. When the pore size is less than 0.08 mu m, there is a problem that the gas absorption rate is rapidly lowered when applied to a gas- , And if it is more than 10 μm, the minimum penetration pressure (0.15 bar) of the gas is significantly lowered, and the gas-liquid contact separation membrane apparatus can not be operated in a non-wetting mode, resulting in a problem that the amount of gas absorption is reduced .

Particularly, it is more preferable that the pore size of the ceramic hollow fiber membrane has a diameter of 0.08 to 1 占 퐉. Due to the characteristic that the contact angle of the absorbing liquid and the surface tension value are lowered in the process of removing the gas- And having a fine pore size can increase the absorption efficiency of carbon dioxide.

At this time, the minimum penetration pressure is also influenced by the hydrophobic (contact angle) characteristic. As the contact angle increases, the hydrophobic property increases and the minimum penetration pressure also increases.

Therefore, the ceramic hollow fiber membrane according to the present invention preferably has a contact angle of 130 to 150 ° with respect to water.

The present invention also relates to a process for preparing a dope solution comprising the steps of: a) mixing a alumina particle, a polymeric binder and a dispersant with triethyl phosphite to prepare a dope solution, b) feeding and discharging the dope solution with an internal coagulant, C) contacting the hollow fiber with an external coagulant to obtain a hollow fiber membrane by washing, drying and sintering through a phase transition process, and d) coating the sintered hollow fiber membrane with a hydrophobic material. A method for producing a hydrophobic ceramic hollow fiber membrane having a novel pore structure is provided.

The step a) is a step of preparing a dope solution, wherein 1 to 20 parts by weight of a polymer binder, 0.1 to 5 parts by weight of a dispersant, and 40 to 100 parts by weight of triethyl phosphite are mixed with 100 parts by weight of alumina particles .

The above content range is a range capable of optimizing the dispersibility in the dope solution and the film formation in the process of producing the hollow fiber membrane. If the content is out of the above range, the dispersibility is lowered or the pore structure of the hollow fiber membrane is not well formed It is not desirable because there is a possibility that it may not be.

Particularly, when the triethylphosphite solvent is used, if the amount of the dispersing agent is less than 0.1 parts by weight, the dispersibility of the dispersing agent tends to be low. Therefore, the stirring is difficult and the viscosity is lower than that of the conventional solvent. Desert radiation is possible.

The alumina is preferably an alpha-alumina (α-Al ₂ O ₃₎ or gamma-alumina _{(γ-Al 2 O 3)} . Particularly, in the present invention, by using alumina as a ceramic material alone without using a composite material, a high porosity and an excellent mechanical strength can be obtained, and thus an excellent effect is obtained even in an economical aspect.

The polymer binder serves as a binder for the alumina particles and is preferably at least one selected from the group consisting of polyethersulfone, polysulfone, polyetherimide, polyamide and polyacrylonitrile.

The dispersing agent serves to improve the dispersibility of the alumina particles in the organic solvent, and is preferably polyvinylpyrrolidone or polyvinyl alcohol.

The triethyl phosphite serves as an organic solvent to form the pore structure of the hollow fiber membrane into a sponge structure.

Particularly when an organic solvent such as n-methylpyrrolidone, dimethylformamide, dimethylacetamide or dimethylsulfoxide other than the triethylphosphite is used as the organic solvent, only a part of the sponge structure is formed and mixed with the finger structure . Therefore, the triethyl phosphite must be used alone to form the sponge structure singly.

As described above, when the sponge structure is formed into a single structure, the absorption amount of carbon dioxide, that is, the permeability can be increased, and swelling phenomenon of pores does not occur, and therefore, the sponge structure exhibits an excellent effect in terms of stability as a gas separation membrane.

The step b) is preferably a step of forming a hollow fiber, and the dope solution is preferably carried out with an internal coagulant in a double spinning nozzle at an extrusion pressure of 0.5 to 7 bar. This is because the triethylphosphite solvent It is necessary to use higher radiation pressure than the conventional solvent. In addition, it is preferable that the air gap is supplied at 20 cm or less and discharged to form a hollow fiber, that is, the air gap can be radiated at zero, more preferably 0.01 to 20 cm. If the air gap is more than 20 cm, the hollow fiber membrane is spun and cut off.

Therefore, when the extrusion pressure is out of the range of the air gap, it is difficult to control the pore structure, which is not preferable.

In the present invention, since the pore structure of the hollow fiber membrane can be adjusted by using the double spinning nozzle without using three or more spinning nozzles, the process for producing the hollow fiber membrane is convenient.

As the internal coagulant, a substance capable of forming pores in the separation membrane through interaction with a solvent in the dope solution is used. Any solvent having a hydroxyl group (-OH) function can be used, preferably water, ethanol , Propanol, and butanol.

The step c) is preferably a step of obtaining a hollow fiber membrane, wherein the hollow fiber formed through the step b) is contacted with an external coagulant and subjected to phase transformation at room temperature for 10 to 40 hours. It is further preferable that the hollow fiber is dried at a temperature of 100 to 200 ° C for 10 to 40 hours and then sintered at a temperature of 400 to 1500 ° C to produce a hollow fiber membrane.

Wherein the sintering is performed by a first sintering step of sintering at a temperature of 400 to 800 ° C, a second sintering step of sintering at a temperature of 800 to 1200 ° C after the first sintering step, Lt; RTI ID = 0.0 &gt; 1500 C < / RTI &gt; At this time, the sintering temperature is preferably in the order of first sintering <second sintering <third sintering, and the third sintering temperature is the highest.

At this time, the rate of temperature increase for reaching the first sintering temperature is preferably 1 to 5 ° C / min, and the rate of temperature rise for reaching the second and third sintering temperatures is preferably 2 to 10 ° C / min. (It is more preferable that the rate of temperature rise of the secondary and tertiary is higher than the rate of temperature rise of the primary.) The water and the polymer in the hollow fiber membrane (solvent, binder, and additive used in the preparation of the dope solution) It is preferable to carry out the above-described three-step sintering process. That is, a single alumina hollow fiber membrane having no impurities can be formed in order to secure high mechanical strength and phase stability through the above three-step sintering process.

In the step d), the hollow fiber membrane is coated with a hydrophobic substance to modify the surface thereof, and the hollow fiber membrane is coated on the perfluorooctylethyltrimethoxysilane solution to coat the hollow fiber membrane.

The perfluorooctylethyltrimethoxysilane chemically bonds through a coupling reaction in which a hydrogen ion reacts with a hydroxyl group on the surface of the ceramic hollow fiber membrane at a terminal methyl group and releases water, The carbon chain at the opposite end of the toxic silane comes out of the surface of the hollow fiber membrane and functions to hydrophilize the hydrophilic hydroxy group.

The perfluorooctylethyltrimethoxysilane solution is prepared by dissolving a perfluorinated alkylsilane compound in an organic solvent such as n-hexane, and the solution is preferably used at a concentration of 0.005 to 0.05 mol / L. If the concentration range is less than 0.005 mol / L, the coating layer is difficult to uniformly form. If the concentration range is more than 0.05 mol / L, the coating layer becomes too thick to lower the absorption rate of carbon dioxide.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. 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 and scope of the present invention as set forth in the following claims. It is natural that it belongs to the claims.

In addition, the experimental results presented below only show representative experimental results of the embodiments and the comparative examples, and the respective effects of various embodiments of the present invention which are not explicitly described below will be specifically described in the corresponding part.

(Reagents and apparatus)

1. Reagents

E6020P)에서 구입한 것을 사용하였다. 그리고 polyvinylpyrrolidone 은 SIGMA-ALDRICH 사에서 구입한 것을 사용하였고, Heptadecafluoro-1, 1, 2, 2-tetrahydrodecyltrimethoxsilane(perfluoro-octylethyl trimethoxy silane, ≥98%)는 SOOYANG chemtec 사에서 구입한 것을 사용하였다.(99.5%), dimethylsulfoxide (99.8%), dimethylacetamide (99.5%) and n-hexane (96%) were purchased from SAMCHUN PURE chemical and triethylphosphite (99% The polyethersulfone was purchased from BASF (Ultrason

E6020P) was used. The polyvinylpyrrolidone was purchased from SIGMA-ALDRICH. Heptadecafluoro-1, 1, 2, 2-tetrahydrodecyltrimethoxysilane (perfluoro-octylethyl trimethoxy silane, ≥98%) was purchased from SOOYANG chemtec.

2. Organization

The vacuum pump used was IDP-3 from Varian, the S-4800 from Hitachi, and the Vertex-70 from Bruker for infrared spectrophotometer. The contact angle measuring apparatus was Phoenix-I manufactured by SEO, and the X-ray diffractometer was Rigaku's ultima IV.

As shown in FIG. 7, the apparatus used for the carbon dioxide absorption experiment was a module formed by inserting a hollow fiber membrane into a tube made of stainless steel, sealing it with an epoxy adhesive, and connecting both ends to fittings. The module used a single membrane module to complete the carbon dioxide absorbing device. Nitrogen of 99.9999% purity was pressurized to 5 bar on each line before the experiment, and it was confirmed that the leakage of the water was not caused by snoopy (TM Swagelok). CO2 and nitrogen of 99.9999% purity were supplied to the experimental module using a mass flow controller (5850E, Brooks). The absorbing solution was a GEA pump (REGLO-Z Digital , ISMATEC Co., Ltd.).

( Example ) Triethyl phosphite ( 트리 에릭스 플러스 , TEP ) Preparation of Hydrophobic Alumina Hollow Fiber Membrane Using Solvent

Polyethersufone was added to triethylphosphite solvent and stirred at a speed of 150 rpm. 360 g of α-Al ₂ O ₃ powder and 6 g of polyvinylpyrrolidone were added and stirred to prepare a dope solution. The prepared dope solution is placed in a stainless steel tank and defoaming process is performed using a vacuum pump for 1 hour. The dope solution subjected to the defoaming process was spinned using a nozzle having an inner diameter of 1.2 mm and an outer diameter of 3 mm to produce a hollow fiber membrane. The hollow fiber membrane was subjected to phase transformation for one day, dried, and then dried at a temperature of 1300 ° C. And sintered. Finally, in order to modify the surface of the sintered hollow fiber membrane to hydrophobicity, perfluoro-octylethyl trimethoxy silane was dissolved in n-hexane solvent at a concentration of 0.01 mol / L to prepare a hollow fiber membrane. 2 hours, washed three times with n-hexane, and dried in an oven at 120 ° C. for 24 hours to prepare an alumina hollow fiber membrane whose surface was modified to be hydrophobic. (Conditions for spinning were as shown in Table 1 below).

( Comparative Example  1) n- methyl -2- Pyrrolidone (n-methyl-2- 피리로드로one , NMP ) Preparation of Hydrophobic Alumina Hollow Fiber Membrane Using Solvent

The procedure of Example 1 was repeated except that 1-methyl-2-pyrrolidone was used instead of triethylphosphite.

( Comparative Example  2) Dimethyl sulfoxide ( dimethyl sulfoxide , DMSO ) Preparation of Hydrophobic Alumina Hollow Fiber Membrane Using Solvent

The procedure of Example 1 was repeated except that dimethylsulfoxide was used instead of triethylphosphite.

( Comparative Example  3) Dimethylacetamide ( dimethylacetamide , DMAc ) Preparation of Hydrophobic Alumina Hollow Fiber Membrane Using Solvent

The procedure of Example 1 was repeated except that dimethylacetamide was used instead of triethylphosphite.

( Comparative Example  4) Preparation of hydrophilic alumina hollow fiber membrane

Polyethersufone was added to the triethylphosphite solvent and stirred at a speed of 150 rpm. 360 g of α-Al ₂ O ₃ powder and 3 g of polyvinylpyrrolidone were added and stirred to prepare a dope solution. The prepared dope solution is placed in a stainless steel tank and defoaming process is performed using a vacuum pump for 1 hour. The dope solution subjected to the defoaming process was spun using a nozzle having an inner diameter of 0.4 mm and an outer diameter of 1.75 mm to produce a hollow fiber membrane. The hollow fiber membrane was subjected to phase transformation for one day, dried, and then dried at a temperature of 1300 ° C And sintered to produce a hollow fiber membrane.

division Air gap (cm) Inner coagulant rate (ml / min) Extrusion pressure (N ₂ , bar) Example 10 5 2 Comparative Example 1 10 10 One Comparative Example 2 10 10 One Comparative Example 3 10 10 One Comparative Example 4 10 5 2

3 is an image showing the results of measurement of cross sections of the alumina hollow fiber membranes of Examples and Comparative Examples 1 to 3 by scanning electron microscopy (SEM), wherein (a) is an example, (b) 1, (c) shows Comparative Example 2, and (d) shows Comparative Example 3.

Referring to FIG. 3, it can be seen that, in the case of the hollow fiber membranes of Comparative Examples 1 to 3, the finger structure is formed on the inner side, the outer side, or both sides of the hollow fiber membrane cross section, and there is a sponge structure therebetween. On the other hand, in the case of the embodiment, it can be seen that the entire cross section is formed in a sponge structure and the finger structure disappears.

FIG. 4 is an image showing the results of measurement of the contact angle using the contact angle measuring apparatus of the hollow fiber membranes of Examples and Comparative Examples 1 to 4, wherein (a) is an example, (b) Comparative Example 2, (d) shows Comparative Example 3, and (e) shows Comparative Example 4.

In the case of Comparative Example 4, the hydrophobic surface was not modified and the surface was hydrophilic. As a result, the water was absorbed into the hollow fiber membrane, so that the contact angle could not be measured. On the other hand, in the case of the hydrophobic-modified surface and the comparative examples 1 to 3, it can be seen that they all have a contact angle of 120 ° or more. In particular, in the case of the embodiment, it can be confirmed that the contact angle is the highest value of 134 °.

In other words, it can be confirmed that the surface of the hollow fiber membrane is modified to be hydrophobic. Therefore, even when the liquid pressure is higher than the gaseous pressure when applied to a contact device due to its high hydrophobicity, Lt; / RTI &gt;

FIG. 5 is a graph showing the measurement results of gas permeabilities of the hollow fiber membranes of Examples and Comparative Examples 1 to 3. FIG. The gas permeability was applied to the following equations (1) to (5) to calculate the pore size and the surface porosity of the hollow fiber membrane, and the results are shown in Table 2 below.

는 기체투과도로 단위는 mol/m²·pa·s이다.

는 도입부와 출구부의 압력(Pa)의 산술 평균이다.In the above equation (1), K ₀ and P ₀ are constants calculated by the following equations,

Is the gas permeability and the unit is mol / m ² · pa · s.

Is the arithmetic mean of the pressure Pa at the inlet and outlet.

은 표면 기공도를 나타낸다. 상기 기공크기 r_p와 표면기공도

를 각각 상수로 나타내면 다음 식 (4), (5)와 같다.In the above formulas (2) and (3), R is a gas constant, M is a molecular weight, T is an absolute temperature, r _p is a pore size,

Represents surface porosity. The pore size r _p and the surface porosity

(4) and (5), respectively.

It can be seen that the gas permeability is linearly proportional to the average pressure difference, and the pore size and surface porosity can be determined by calculating two constants through linear analysis.

division K ₀
(mol / m ² Pa s) P ₀
(mol / m ² Pa s) Poresize
(탆) Surface Porosity
(m ^-1 ) Example 8.22 x 10 ^-5 3.08 x 10 ^-10 0.332 3854 Comparative Example 1 7.29 x 10 ^-5 1.73 × 10 ^-10 0.210 5398 Comparative Example 2 4.84 × 10 ^-5 7.83 × 10 ^-11 0.143 5257 Comparative Example 3 7.02 x 10 ^-5 1.05 x 10 &lt; ^-10 &gt; 0.130 8200

FIG. 6 is a graph showing the measurement results of the absorbed amounts of carbon dioxide in the hollow fiber membranes of Examples and Comparative Examples 1 to 3.

Experimental conditions were as follows: 15% CO 2 gas was supplied from outside of the hollow fiber membrane at a flow rate of 10 to 50 ml / min at room temperature, and 10 wt% aqueous MEA solution was fed toward the inside of the hollow fiber membrane at a flow rate of 10 ml / min . The characteristics of the modules used in the experiment are shown in Table 3 below. After 30 minutes passed after the start of the carbon dioxide absorption experiment, when the steady state was reached, the gas passing through the apparatus was analyzed by gas chromatography (GC) Was calculated by the following formula (6).

In Equation (6), J _co2 is the absorption amount (mol / m ² · s) of carbon dioxide, and q _co2in and q _co2out are the carbon dioxide flow rate (m ³ / s) T is the operating temperature (K) of the process, and A is the effective cross-sectional area of the separator, determined by the following equation (7).

In the formula (7), L represents the effective length (m) of the hollow fiber membrane, and d _out and d _in represent the outer diameter (m) and inner diameter (m) of the hollow fiber membrane, respectively.

Referring to FIG. 6, it can be seen that the absorption amount increases as the sponge structure develops. This is because the pore size of the sponge structure is smaller than that of the finger structure, but the capillary phenomenon does not occur in the sponge structure, so that the permeability of carbon dioxide due to the liquid phase, which is absorbed together with the pores, is suppressed. That is, the permeability of carbon dioxide is increased compared to the finger structure, and the absorption amount of carbon dioxide finally absorbed is increased.

Classification (Unit: mm) Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Hollow fiber membrane Outer diameter 1.77 2.22 2.47 1.73 Inner diameter 1.01 1.44 1.77 0.86 Length 150 150 150 150 module Inner diameter 35.15 35.15 35.15 35.15 Outer diameter 42.30 42.30 42.30 42.30

Therefore, according to various embodiments of the present invention, by controlling the pore structure of the ceramic hollow fiber membrane to form the sponge structure into a single structure, the resistance of the gas and the hollow fiber membrane is minimized, thereby improving the permeation amount of carbon dioxide.

In addition, since the hydrophobic property of the surface of the ceramic hollow fiber membrane is improved, the movement of the gas through the pores and the mass transfer of the gas are facilitated. Therefore, when the ceramic hollow fiber membrane is applied to a gas- And exhibit remarkable effects.

Claims (13)

delete delete delete a) mixing alumina particles, a polymeric binder and a dispersant with triethyl phosphite to prepare a dope solution;
b) feeding and discharging the dope solution to a dual spinneret with an internal coagulant to form a hollow fiber;
c) contacting the hollow fiber with an external coagulant to obtain a hollow fiber membrane by drying and sintering the polymer through a phase transition process; And
d) coating the sintered hollow fiber membrane with a hydrophobic material,
Wherein the step a) comprises mixing 1 to 20 parts by weight of a polymer binder, 0.1 to 5 parts by weight of a dispersant, and 40 to 100 parts by weight of triethyl phosphite with respect to 100 parts by weight of alumina particles. Desert manufacturing method.
5. The method of claim 4,
Wherein the hydrophobic ceramic hollow fiber membrane has a sponge-like structure of 95 to 100% of a cross-sectional area, and has pores having a diameter of 0.08 to 10 占 퐉.
delete 5. The method of claim 4,
The step b)
Wherein the hydrothermal treatment is carried out in an atmosphere of an extrusion pressure of 0.5 to 5 bar and an air gap of 20 cm or less.
5. The method of claim 4,
The phase transition is carried out at room temperature for 10 to 40 hours,
Wherein the drying is performed at a temperature of 100 to 200 DEG C for 10 to 40 hours.
5. The method of claim 4,
A sintering step of sintering at a temperature of 400 to 800 캜;
A second sintering step of sintering at a temperature of 800 to 1200 ° C after the first sintering step; And
And a third sintering step in which the sintering is performed at a temperature of 1100 to 1500 ° C after the second sintering step.
(The above temperature is the first sintering temperature < the second sintering temperature < the third sintering temperature)
5. The method of claim 4,
Wherein the polymeric binder is at least one selected from the group consisting of polyethersulfone, polysulfone, polyetherimide, polyamide, and polyacrylonitrile.
5. The method of claim 4,
Wherein the dispersant is polyvinylpyrrolidone or polyvinyl alcohol. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
delete delete

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