KR20030012224A - A method for separation of carbon dioxide using a polyvinylidene difluoride hollow fiber membrane contactor - Google Patents

Abstract

The present invention relates to a method for separating carbon dioxide using a polyvinylidene difluoride (PVDF) hollow fiber membrane contactor, and more particularly, to fabricate and absorb an asymmetric microporous PVDF hollow fiber membrane prepared by wet spinning in a phase transition process. We developed a hybrid hollow fiber membrane contactor system in which a module and a desorption module were combined, and a hybrid system in which an absorption module and a thermal stripper were combined.As an absorbent, aqueous solutions such as water as a physical absorbent and monoethanolamine as a chemical absorbent were used. The present invention relates to a method for separating carbon dioxide using a PVDF hollow fiber membrane contactor having superior carbon dioxide separation and recovery performance as compared with the case where a PP hollow fiber membrane contactor having a conventional symmetric porous structure is introduced into an absorption module or a desorption module.

Description

A method for separation of carbon dioxide using a polyvinylidene difluoride hollow fiber membrane contactor}

The present invention relates to a method for separating carbon dioxide using a polyvinylidene difluoride (PVDF) hollow fiber membrane contactor, and more particularly, to fabricate and absorb an asymmetric microporous PVDF hollow fiber membrane prepared by wet spinning in a phase transition process. We developed a hybrid hollow fiber membrane contactor system in which a module and a desorption module were combined, and a hybrid system in which an absorption module and a thermal stripper were combined.As an absorbent, aqueous solutions such as water as a physical absorbent and monoethanolamine as a chemical absorbent were used. The present invention relates to a method for separating carbon dioxide using a PVDF hollow fiber membrane contactor having superior carbon dioxide separation and recovery performance as compared with the case where a PP hollow fiber membrane contactor having a conventional symmetric porous structure is introduced into an absorption module or a desorption module.

As the global warming gas, carbon dioxide generation, which contributes about 55% of the total gas, is closely related to the increase in energy demand, and the amount emitted from thermal power plants, steel mills, cement plants, and other chemical-related plants is equivalent to the total CO2 emissions. Accounting for about 70%. As a result, efforts are being made to diversify and recover carbon dioxide worldwide.

Carbon dioxide separation and recovery techniques can be classified into absorption method, adsorption method, membrane separation method and deep cooling method. Each of these methods has its characteristics, advantages and disadvantages, and is selected according to the conditions to be actually used. Absorption method is the oldest separation process applied to carbon dioxide separation and is currently applied to thermal power plants and steel mills. However, there are many problems such as excessive energy consumption due to the regeneration of the absorbent liquid, overflow and drift of the absorbent liquid in the absorption tower, low contact area between the gas and the liquid, and corrosiveness of the absorbent liquid. In addition, the adsorption method has been applied to some gas treatment processes along with the study of various adsorbents, but it has yet to be solved for the carbon dioxide separation and recovery process such as large equipment size, expensive adsorbent price, unpredictable operating variables and difficulty in accurate process design. There are many problems.

Therefore, in recent years, researches on hybrid systems combining existing processes have been made in an effort to solve the problems of these processes and to obtain higher efficiency. In particular, research results have been reported that the hybrid of the absorption method and the membrane method is very excellent in terms of economy, separation efficiency, and ease of operation. The hybrid system of the absorption method and the membrane method can overcome the technical disadvantages of the existing absorption method by replacing the fixed column of the absorber with a porous hydrophobic polymer hollow fiber membrane contactor. In addition to these technical advantages, the hollow fiber membrane contactor, in which gas and liquid contact with each other through a polymer separation membrane, has a large total area of gas-liquid contact due to the large effective area per unit volume. On the other hand, the hollow fiber membrane contactor may reduce the material transfer rate by generating a material transfer resistance by the membrane depending on the structure of the membrane, and if there is a boundary between phases in the pores of the hollow fiber membrane, There is a problem to operate.

The polymer separator currently used as a hollow fiber membrane contactor includes polytetrafluoroethylene (PTFE), polypropylene (PP) hollow fiber membrane, and the like. PTFE and PP hollow fiber membranes are excellent in chemical resistance and mechanical properties, and particularly excellent in hydrophobicity and have a high critical pressure when they have an appropriate pore size. However, the PTFE or PP hollow fiber membrane is a symmetrical separator having the same structure as the surface skin layer and the lower support layer due to the material and manufacturing characteristics, and has a large material transfer resistance to the permeable material. Therefore, the material transfer resistance by the membrane has a disadvantage of partially canceling the fast overall material transfer rate due to the large effective area per unit volume, which is the biggest advantage of the hollow fiber membrane contactor.

Therefore, there is a need for a hollow fiber membrane having a film thickness and high surface porosity that can minimize the membrane resistance. Recently, the results of the researches related to the thickness of the membrane showed that the asymmetric porous hollow fiber membrane was 2-8 times higher in the demelting gas process using the hollow fiber membrane contactor than the symmetrical PP hollow fiber membrane. There is an example where the results have been reported [K.Li etc. Chemical Engineering Science . Vol. 53, No. 6, pp. 1111-1119, 1998]. In addition, K.Li et al., Through the study of selectively separating H ₂ S from waste gas stream using 10% NaOH as an asymmetric porous PVDF hollow fiber membrane contactor and an absorber, can reduce membrane resistance as compared to symmetric porous PP hollow fiber membrane. [ AIChE , Vol. 45, No. 6, June 1999].

Therefore, in the present invention, asymmetric microporous polyvinylidene fluoride (PVDF) hollow fiber membranes having excellent hydrophobicity and chemical resistance, such as PTFE or PP, are introduced into the contactor device to develop a high efficiency carbon dioxide separation and recovery system. It was. As a result, a combination of an absorption module and a desorption module consisting of an asymmetric microporous PVDF hollow fiber membrane contactor, a circulatory hollow fiber membrane contactor system in which a carbon dioxide absorbent is continuously circulated between the two modules, and A hybrid system is constructed in which the absorbent circulates two parts continuously by combining the absorption module and the thermal stripper used in the existing absorption method.

Accordingly, an object of the present invention is to provide a highly efficient carbon dioxide separation and recovery system by constructing a hybrid system with a circulating hollow fiber membrane contactor using an absorption and desorption module composed of asymmetric microporous PVDF hollow fiber membranes.

1 is a scanning electron microscope (SEM) photograph of a cross-section of an asymmetric microporous polyvinylidene difluoride (PVDF) hollow fiber membrane prepared by wet spinning in a phase transition process.

2 is a photograph of an asymmetric microporous polyvinylidene difluoride (PVDF) hollow fiber membrane module used as an absorption / desorption module.

3 is a schematic diagram of a circulating hollow fiber membrane contactor system in which an absorption module and a detachment module are combined.

4 is a schematic diagram of a hybrid system combining an absorption module and a thermal desorber.

[Description of Symbols for Main Parts of Drawing]

1: hollow fiber membrane contactor 2: thermal stripper

3: cooler 4: reboiler

5: pump 6: vacuum pump

7: Mass flow controller (MFC)

8: gas chromatography (GC)

The present invention is a gas separation method using an asymmetric microporous polyvinylidene difluoride hollow fiber membrane,

1) A spinning solution containing 9 to 17% by weight of polyvinylidene difluoride, 0.1 to 20% by weight of lithium chloride, 0.1 to 20% by weight of zinc chloride or diethylene glycol dimethyl ether, and 70 to 90% by weight of a solvent was prepared. Next, asymmetric microporous polyvinylidene difluoride hollow fiber membranes are prepared by wet spinning in a phase transfer method;

2) preparing a module using the manufactured hollow fiber membrane, and then mounting it on a carbon dioxide separation system; And

3) water (H ₂ O) as a physical absorbent in the system; As the chemical absorbent selected from alkali metal carbonates, alkali metal hydroxides and alkanolamines; Separation of carbon dioxide by supplying a mixed gas containing carbon dioxide

Characterized in that the carbon dioxide separation method using a polyvinylidene difluoride hollow fiber membrane contactor comprising a.

The present invention will be described in more detail as follows.

1) Preparation of Hollow Fiber Membrane

A spinning solution containing 9 to 17% by weight of polyvinylidene difluoride, 0.1 to 20% by weight of lithium chloride, 0.1 to 20% by weight of zinc chloride or diethylene glycol dimethyl ether, and 70 to 90% by weight of a solvent was prepared. A step of preparing an asymmetric microporous polyvinylidene difluoride hollow fiber membrane by wet spinning of a phase transition method is performed.

The manufacturing method of such an asymmetric microporous polyvinylidene difluoride hollow fiber membrane will be described in detail by process.

First, a spinning solution containing 9 to 17% by weight of polyvinylidene difluoride, 0.1 to 20% by weight of lithium chloride, 0.1 to 20% by weight of zinc chloride or diethylene glycol dimethyl ether, and 70 to 90% by weight of a solvent is prepared. .

The polyvinylidene difluoride is a material of the hollow fiber membrane, and is dissolved in aprotic solvents such as dimethylacetamide, dimethylformamide, methylpyrrolidone, and acetone, and is resistant to oxidation and inorganic acids, organic acids, aliphatic and aromatic hydrocarbons, It has excellent durability against alcohol, halogenated solvent and the like, and shows excellent physical properties at -50 to 140 ° C. Such polyvinylidene difluoride is preferably contained 9 to 17% by weight of the total spinning solution, if the content is less than 9% by weight there is a problem that the pore size is larger than the control range, exceeding 17% by weight There is a problem that the porosity is lowered. In addition, the polyvinylidene difluoride preferably has a molecular weight of 200,000 to 800,000, Kynar 761 (Mw 520,000), 760 (Mw 444,000), 721 (Mw 275,000) manufactured by Elf Autochem, USA. , 720 (Mw 245,000) and the like can be used.

Since the PVDF is a very hydrophobic material, it is difficult to form pores because the coagulation agent and the solvent are not easily exchanged during the phase transition process. Thus, in order to solve this problem, lithium chloride (LiCl) may be used as a pore-forming agent. It is preferable to contain 0.1 to 20% by weight of the total spinning solution, and if the content is less than 0.1% by weight, there is a problem of low porosity, and if it exceeds 20% by weight, the porosity increases but the pore size increases together. There is.

In the present invention, the pore growth inhibitor, which serves to control the pore size within a certain range regardless of the porosity change, may use zinc chloride or diethylene glycol dimethyl ether, and preferably contain 0.1 to 20% by weight of the total spinning solution. If the content is less than 0.1% by weight, the porosity increases but the pore size increases together, and if the content exceeds 20% by weight, there is a low porosity problem.

The present invention is characterized by using a pore former and a pore growth inhibitor together. The pore former and the pore growth inhibitor are formed in the PVDF hollow fiber membrane according to the present invention by interacting with a polymer material or a solvent, respectively. There is an advantage of increasing the porosity and making the pore size of the surface skin layer fine.

The solvent is dimethylacetamide (N, N-dimethylacetamide, DMAc), dimethylformamide (N, N-dimethylformamide, DMF), dimethyl sulfoxide (DMSO), methylpyrrolidone (N-methyl-2 single or two or more mixed solvents selected from -pyrrolidone (NMP), triethyl phosphate (TEP), acetone, methylethyl ketone and tetrahydrofuran (THF) It is preferable to contain 70 to 90% by weight of the total spinning solution, and if the content is less than 70% by weight, there is a problem that the porosity is greatly reduced along with the pore size. There is a problem that grows beyond this certain range.

Then, the prepared asymmetric microporous PVDF hollow fiber membrane is prepared by a wet or dry spinning method using a nozzle in the form of a tube-in-orifice. The phase transition process may use water or a water / organic solvent mixed aqueous solution as an internal coagulant and an external coagulant, and the organic solvent may be alcohol, dimethylacetamide, dimethylformamide, methylpyrrolidone or acetone.

Finally, the post-treatment of the polyvinylidene difluoride hollow fiber membrane, the polyvinylidene difluoride hollow fiber membrane was stored in water for 7 days at room temperature and then used for 1 hour to 24 hours using hot water of 40 ℃ to 90 ℃ By hydrothermal treatment for a period of time to extract the organic solvent, pore-forming agent and pore growth inhibitor remaining in the membrane. After that, the PVDF hollow fiber membrane was kept in water for 1 day at room temperature, and then immersed in 1 to 100% ethyl alcohol for 1 second to 1 hour, and then 10 to 60% relative humidity for 1 hour to 7 days at a temperature of 10 to 50 ° C. To dry to form the final PVDF hollow fiber membrane.

At this time, the PVDF hollow fiber membrane was confirmed to have a surface effective porosity of more than 70% and a pore size of about 0.001 ㎛ to 0.005 ㎛ by using a gas permeation measurement.

2) Introduction to circulating hollow fiber membrane contactor system or hybrid system

The prepared hollow fiber membrane is introduced into a circulating hollow fiber membrane contactor system composed of an absorption module and a desorption module, or is introduced into a hybrid system composed of an absorption module and a thermal desorber.

That is, the manufactured hollow fiber membrane contactor is manufactured using the manufactured hollow fiber membrane, and then the absorption module and the desorption module are combined devices in which a carbon dioxide absorbent continuously circulates between the two modules. A circulatory hollowfiber membrane contactor system) and the above-described absorption module and the thermal desorber used in the existing absorption method can be used to construct a hybrid system in which the absorbent continuously circulates two parts.

The absorbent module and the detachable module may be manufactured by fixing the hollow fiber membrane using adhesives at both ends of an acrylic tube having a length of 250 mm and an inner diameter of 20 mm. At this time, the porosity and pore size of the polyvinylidene difluoride hollow fiber membrane used are preferably in the range of 10 to 90% and 0.001 to 1 μm, respectively. The hollow fiber membrane arrangement of the absorbent module and the desorption module in the circulating hollow fiber membrane contactor system and the hybrid module is preferably in a parallel or fabric arrangement with the module. In the circulating hollow fiber membrane contactor system, the absorbent module and the desorption module and the hybrid system preferably have a hollow fiber membrane filling density of 0.1 to 0.8.

3) Separation of Carbon Dioxide

The carbon dioxide is separated by supplying a physical gas absorbent, a chemical absorbent, and a mixed gas containing carbon dioxide to the circulating hollow fiber membrane contactor system or hybrid system.

Pure water (H ₂ O) may be used as the physical absorbent, and the chemical absorbent may be potassium carbonate (K ₂ CO ₃ ), which is an alkali metal carbonate, sodium hydroxide (NaOH), or potassium hydroxide, which is an alkali metal hydroxide. The hydroxide (KOH), monoethanol amine (MEA) which is alkanolamines, diethanolamine (DEA), triethanolamine (TEA), diamine oisopropanol (DAIP), methyl diethanolamine (MDEA), etc. can be used.

The cyclic hollow fiber membrane contactor system is a principle that the absorbent and the mixed gas continuously circulate through the absorbent module and the desorption module. In the desorption module, the absorbent flows to the inside of the hollow fiber membrane (tube-side) and the module shell-side is operated by reducing the pressure, or the absorbent flows to the module shell-side, and the hollow fiber membrane The tube-side can be operated by reducing the pressure. Desorption drive force in the desorption module is generated through vacuum or sweep gas.

In the hybrid system, the absorbent and the mixed gas continuously circulate the absorbent module and the thermal desorber. As a thermal desorber, dual columns used in existing absorbers can be used.

In the absorption module of each system, the flow of the mixed gas and the absorbent is countercurrent, and the pressure difference between the mixed gas and the absorbent in the absorbent module is maintained at 1 atm or less, and the operating temperature of the absorbent module and the desorption module is 1 to 80 ° C. Is preferred. A pulsation-free gear pump is used to circulate the absorbent between the absorption module and the desorption module or between the absorption module and the thermal desorption device. The flow rate of the mixed gas injected into the absorption module is controlled using a flow controller.

In addition, the desorption module maintains 1 to 500 torr using a vacuum pump and a vacuum pressure regulator, and the temperature of the thermal desorber is operated at 20 to 150 ° C. In the hybrid system, a heat exchanger is installed between the heat desorber and the absorbent module to reduce the absorbent and inject it into the absorbent module. Carbon dioxide removal rate can be measured by using a gas chromatograph (GC) at the gas inlet and outlet of the absorption module, respectively.

The results of introducing the circulating hollow fiber membrane contactor system and hybrid system using the asymmetric microporous PVDF hollow fiber membrane contactor developed by the present invention and the conventional commercialized symmetric porous PP (Memtech) hollow fiber membrane into the system, As a result of comparing and analyzing the results of the carbon dioxide separation and recovery experiment by combining the conventional absorption device, that is, the fixed column and the thermal desorber, it was found that the separation efficiency of carbon dioxide according to the present invention is better.

Hereinafter, the present invention will be described in more detail based on the following examples, but the present invention is not limited to the examples.

Preparation Example 1 Preparation of PVDF Hollow Fiber Membrane

15 wt% of polyvinylidene difluoride (PVDF, Kynar 761 (Mw = 520,000) from Elf Autochem, USA), 3.75 wt% of lithium chloride (LiCl), 1.25 wt% of zinc chloride (ZnCl ₂ ) A spinning solution was prepared by dissolving in 80% by weight of dimethylacetamide (DMAc). An asymmetric microporous PVDF hollow fiber membrane was prepared through a wet spinning process using the prepared spinning solution using a tube-in-orifice nozzle. At this time, non-solvent water was used as the internal coagulant and the external coagulant. The PVDF hollow fiber membranes were stored in water at room temperature for 7 days and then treated with hot water for 60 hours using hot water at 60 ° C. to extract organic solvents, pore formers, and pore growth inhibitors remaining in the membrane. After the PVDF hollow fiber membrane subjected to the post-treatment process was stored in water for 1 day at room temperature, immersed in 100% ethanol for 20 seconds and dried at room temperature for 2 days to obtain a polyvinylidene difluoride hollow fiber membrane.

Example 1

Absorption and desorption modules were prepared by fixing the asymmetric microporous PVDF hollow fiber membrane obtained in Preparation Example 1 using an adhesive to both ends of an acrylic tube having a length of 250 mm and an inner diameter of 20 mm, and the hollow fiber membrane packing density was 0.4. The circulating hollow fiber membrane contactor system was constructed using the manufactured absorption and desorption modules, and the mixed gas was a simulated gas in which nitrogen and carbon dioxide were mixed by 80% and 20%, respectively, and the flow rate was controlled by using a flow controller. Absorbent was chemically absorbent, 5 wt% monoethanolamine (MEA), and a pulsation-free gear pump was used to circulate between the absorbent module and the desorption module. The pressure difference between the gas and the absorbent in the absorption module was kept below 1 atm, the flows flowed countercurrently, and the desorption module was maintained at 50 torr using a vacuum pump and a vacuum pressure regulator. In the absorption module, the mixed gas and the absorbent were flowed into the tube-side and the shell-side of the hollow fiber membrane, respectively. In the desorption module, the absorbent containing carbon dioxide was flowed into the tube-side of the hollow fiber membrane. The shell-side was depressurized. In addition, the flow rates of the mixed gas and the absorbent in the absorption module were operated at 450 cc / min and 20 cc / min, respectively, and the carbon dioxide removal rate was measured using gas chromatograph (GC) at the gas inlet and outlet of the absorption module, respectively. .

Example 2

In the desorption module, carbon dioxide-containing absorbents were flowed to the shell-side of the module, and carbon dioxide adsorption / desorption experiments were carried out in the same manner as in Example 1 except that the inside of the hollow fiber membrane was depressurized. It was.

Example 3

Carbon dioxide adsorption / desorption experiments were carried out in the same manner as in Example 1 except that water absorbent was used as water as a physical absorbent.

Example 4

An absorption module was manufactured in the same manner as in Example 1, and a hybrid system was constructed by combining the manufactured absorption module and the thermal desorber. The mixed gas was a simulated gas in which nitrogen and carbon dioxide were mixed by 80% and 20%, respectively, and the flow rate was controlled by using a flow controller. The absorbent is a 5% by weight monoethanolamine (MEA), a chemical absorbent. A pulsation-free gear pump is used to circulate between the absorbent module and the thermal desorber. The temperature of the absorbent module and the thermal desorber is fixed at 30 ℃ and 130 ℃, respectively. . The pressure difference between the gas and the absorbent in the absorbent module was kept below 1 atm, the flows flowed countercurrently, and the heat absorber was installed between the thermal desorber and the absorbent module to reduce the absorbent and then injected into the absorbent module. In the absorption module, the mixed gas and the absorbent were flowed into the tube-side and the shell-side of the hollow fiber membrane, respectively, and the flow rates of the mixed gas and the absorbent were operated at 450 cc / min and 20 cc / min, respectively. The carbon dioxide removal rate was measured using gas chromatograph (GC) at the gas inlet and outlet of the absorption module, respectively.

Example 5

Carbon dioxide adsorption / desorption experiments were carried out in the same manner as in Example 4 except that the water absorbent was used as water as a physical absorbent.

Comparative Example 1

Using a symmetric porous PP hollow fiber membrane (Memtech, pore size: 0.02 ~ 0.05 ㎛, porosity: 70%) as in Example 1 to prepare a hollow fiber membrane contactor was used as an absorption module. Otherwise, all the experimental conditions were performed in the same manner as in Example 1 to conduct carbon dioxide adsorption / desorption experiments.

Comparative Example 2

Carbon dioxide adsorption / desorption experiments were carried out under the same conditions as in Comparative Example 1 except that water absorbents were used as water absorbents.

Comparative Example 3

Using the absorption module manufactured in the same manner as in Comparative Example 1 to build a hybrid system combining the absorption module and the thermal desorber. Otherwise, all the experimental conditions were carried out in the same manner as in Example 4 to conduct a carbon dioxide adsorption / desorption experiment.

Comparative Example 4

Carbon dioxide adsorption / desorption experiments were carried out under the same conditions as in Comparative Example 3 except that water absorbents were used as water absorbents.

The cyclic hollow fiber membrane contactor and hybrid system for carbon dioxide separation and recovery constructed in Examples 1 to 5 exhibited high separation efficiency, and the results are shown in Table 1 below.

As can be seen from Table 1, when water, a physical absorbent, was used as the absorbent, the carbon dioxide removal efficiency was much lower than that of the chemical absorbent MEA. As in the comparative example, the absorption module prepared from the conventional commercialized symmetric porous PP hollow fiber membrane was introduced into the above system, and the carbon dioxide separation and recovery experiments were conducted. In comparison, the carbon dioxide separation efficiency was reduced.

Test Example: Existing Carbon Dioxide Absorber

Carbon dioxide separation efficiency was measured using a conventional carbon dioxide absorber consisting of a fixed column and a thermal desorber. A fixed column using a glass 1/2 inch raschig ring as a filler was used, and the volume of the fixed column was 1.5 times larger than that of the asymmetric microporous PVDF hollow fiber membrane absorbing module developed in the present invention. In addition, the thermal desorber was used as it is in the thermal desorber used in Example 4, the absorbent was used as a water absorbing agent and 5% monoethanolamine (MEA) aqueous solution of the chemical absorbent. Table 2 shows the carbon dioxide separation efficiency of the existing absorber (fixed column + thermal desorption unit).

From the results of Table 2, it can be seen that the existing absorber is less carbon dioxide removal efficiency than the cyclic hollow fiber membrane contactor system or hybrid system developed in the present invention.

From the above results, the high-efficiency carbon dioxide separation and recovery system developed in the present invention, that is, the cyclic hollow fiber membrane contactor system and hybrid system using asymmetric microporous PVDF hollow fiber membrane contactor, were compared with the case of introducing the conventional symmetric porous PP hollow fiber membrane. It can be seen that the separation efficiency is greatly improved due to the significant decrease in the mass transfer resistance of the membrane. In addition, the carbon dioxide separation efficiency was excellent compared to the existing absorber. Therefore, the highly efficient carbon dioxide separation and recovery system using the asymmetric microporous PVDF hollow fiber membrane developed in the present invention is expected to have excellent separation performance compared to the conventional separation process.

As described above, in the carbon dioxide separation method using the polyvinylidene difluoride (PVDF) hollow fiber membrane contactor according to the present invention, an asymmetric microporous PVDF hollow fiber membrane prepared by wet spinning in a phase-transfer process is produced as a module for absorption. Circulating hollow fiber membrane contactor system combined with and desorption module and hybrid system combining absorber module and thermal stripper.Aqueous solutions such as water as physical absorbent and monoethanolamine as chemical absorbent are used as absorbent. As a result, the PP hollow fiber membrane contactor having a symmetrical porous structure has an excellent effect of separating and recovering carbon dioxide compared to the case of introducing a PP hollow fiber membrane contactor into an absorption module or a desorption module. Can be.

Claims (15)

In the gas separation method using an asymmetric microporous polyvinylidene difluoride hollow fiber membrane, 1) A spinning solution containing 9 to 17% by weight of polyvinylidene difluoride, 0.1 to 20% by weight of lithium chloride, 0.1 to 20% by weight of zinc chloride or diethylene glycol dimethyl ether, and 70 to 90% by weight of a solvent was prepared. Next, asymmetric microporous polyvinylidene difluoride hollow fiber membranes are prepared by wet spinning in a phase transfer method; 2) preparing a module using the manufactured hollow fiber membrane, and then mounting it on a carbon dioxide separation system; And 3) water (H ₂ O) as a physical absorbent in the system; As the chemical absorbent selected from alkali metal carbonates, alkali metal hydroxides and alkanolamines; Separation of carbon dioxide by supplying a mixed gas containing carbon dioxide Separation method of carbon dioxide using a polyvinylidene difluoride hollow fiber membrane contactor comprising a. The method of claim 1, wherein the porosity and pore size of the polyvinylidene difluoride hollow fiber membrane are 10 to 90% and 0.001 to 1 ㎛, respectively. The method of claim 1, wherein the alkali metal carbonate is potassium carbonate (K ₂ CO ₃ ); The alkali metal hydroxide may be sodium hydroxide (NaOH) or potassium hydroxide (KOH); The alkanolamine is a method for separating carbon dioxide, characterized in that selected from monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diaminoisopropanol (DAIP) and methyldiethanolamine (MDEA). The method of claim 1, wherein the mixed gas has a concentration of carbon dioxide (CO ₂ ) of 1 to 99% (v / v). The method of claim 1, wherein the carbon dioxide separation system is a cyclic hollow fiber membrane contactor system consisting of an absorption module and a desorption module. The method of claim 5, wherein the circulating hollow fiber membrane contactor system is characterized in that the absorbent and the mixed gas continuously circulate the absorption module and the desorption module. 6. The method of claim 5, wherein in the desorption module of the circulating hollow fiber membrane contactor system, a) the absorbent is allowed to flow into the tube-side, and the shell-side of the module is decompressed, or b) A method of separating carbon dioxide, characterized by flowing the module shell-side and depressurizing the inside of the hollow fiber membrane (tube-side). The method of claim 5, wherein the desorption driving force in the desorption module of the circulating hollow fiber membrane contactor system is generated through vacuum or sweep gas. The method of claim 1, wherein the carbon dioxide separation system is a hybrid system consisting of an absorption module and a thermal desorber. 10. The method of claim 9, wherein the hybrid system is characterized in that the absorbent and the mixed gas continuously circulate through the absorbent module and the thermal desorber. 10. The method of claim 9, wherein the temperature of the thermal desorber is 20 to 150 ℃. 10. The method of claim 5 or 9, wherein the hollow fiber membrane applied to the carbon dioxide separation system is in a parallel or fabric arrangement with respect to the module. 10. The method of claim 5 or 9, wherein the filling density of the hollow fiber membrane in the module of the carbon dioxide separation system is 0.1 to 0.8. 10. The method of claim 5 or 9, wherein the flow of the mixed gas and the absorbent in the absorption module of the carbon dioxide separation system is countercurrent. 10. The method of claim 5 or 9, wherein the operating temperature of the module in the carbon dioxide separation system is 1 ~ 80 ℃.