KR20070119799A - Preparation method of gas seperation membrane and gas seperation membrane prepared therefrom - Google Patents

Abstract

A preparation method of a gas separation membrane is provided to minimize resistance of a lower part of the membrane, a gas separation membrane prepared by the preparation method is provided, and a module to which the gas separation membrane is applied is provided. A preparation method of a gas separation hollow fiber membrane includes the steps of: (1) spinning a dope solution comprising (A) 25 to 40 wt.% of a polymeric membrane material, (B) 30 to 65 wt.% of a polymer solvent, (C) 1 to 15 wt.% of a polymer or oligomer additive, and (D) 5 to 15 wt.% of a poor solvent additive; (2) solidifying the spun dope solution to form hollow fibers; (3) cleaning and removing a solvent, a poor solvent additive, and a polymer or oligomer additive in the solidified hollow fibers; (4) replacing a solidified solution in the hollow fibers with an organic solvent; and (5) drying the hollow fibers that have been replaced with the organic solvent.

Description

Method for preparing gas separation membrane and gas separation membrane manufactured therefrom {PREPARATION METHOD OF GAS SEPERATION MEMBRANE AND GAS SEPERATION MEMBRANE PREPARED THEREFROM}

1 is a system configuration diagram for showing the dehumidification performance of the gas separation membrane according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: hollow fiber membrane module

100: supply gas inlet 200: dry gas outlet

300: wet gas discharge unit 400: pressure control valve

500: purge flow control valve 600: purge gas inlet

 The present invention relates to a gas separation membrane manufacturing method and a gas separation membrane prepared therefrom with a minimum lower resistance, and more particularly, to prepare a gas separation membrane that can minimize the bottom resistance of the membrane by separately adding a polymer or oligomer to the dope solution during membrane preparation It relates to a method and a gas separation membrane prepared therefrom.

The process of separating a particular gas component from the various gas components in the gas mixture is very important. As a process used to perform such gas separation, a cryogenic method, a pressure swing adsorption method, a membrane separation method, and the like are widely used.

The gas separation membrane used in the membrane separation method is used to separate and concentrate various gases such as hydrogen, helium, oxygen, nitrogen, carbon monoxide, carbon dioxide, water vapor, ammonia, sulfur compounds, and light hydrocarbon gases. There are several fields in which gas separation can be applied, such as separation of oxygen or nitrogen from air and water removal from compressed air. The principle of gas separation using a membrane is based on the difference in permeability of each component in two or more gas mixtures that permeate the membrane. This is a dissolution-diffusion process in which the gas mixture is in contact with one side of the membrane to selectively dissolve at least one of the gas components. In the interior of the membrane a selective diffusion process is carried out through which the gaseous components are passed faster than at least one gaseous component of the gas mixture. Relatively low permeability gas components penetrate the membrane more slowly than at least one or more components of the gas mixture. By this principle, the gas mixture is separated into two streams, which are selectively permeate gas streams and those which are not permeate gas streams. Therefore, in order to properly separate the gas mixture, there is a need for a technique of controlling a structure capable of showing sufficient permeability by selecting a film-forming material having high permeability for a specific gas component.

This membrane structure control technique has been published in US Pat. No. 3,133,132 by Loeb and Sourirajan. Since then, the technology has evolved into a film-making technique, commonly referred to as the phase inversion method, until commercialization of various organic synthetic polymers. The process of preparing the asymmetrical phase separation membrane from the polymer solution by the phase inversion method can be summarized in the following steps:

(1) casting or hollow fiber spinning of polymer dope solution, (2) evaporation of volatile components by contact of dope solution with air, (3) precipitation of solution into coagulation bath, (4) washing, drying, etc. It can be divided into four stages of post-processing step.

In order to selectively separate and concentrate the gas, the membrane structure generally has an asymmetric structure composed of a dense selective separation layer on the membrane surface and a porous support having a minimum permeation resistance at the bottom of the membrane. The ability of the selective separation of gases (hereinafter referred to as selectivity or α), which is a characteristic of the membrane, is determined by the structure of the separation layer, and the permeation rate of the selectively separated gas (hereinafter referred to as permeability or P) is determined by the separation layer. It depends on the thickness and degree of porosity of the porous support, which is the underlying structure of the asymmetric membrane. In order to selectively separate the mixed gas, the surface of the separation layer must be free of defects and the pore size must be 5 kPa or less.

In addition, the separation layer should be as thin as possible in order to achieve high gas permeability, since gas permeability is inversely proportional to the effective membrane thickness. In order to minimize resistance to gas flow selectively passing through the separation layer, it is advantageous for the understructure of the asymmetric membrane to have a porous structure if possible.

Two methods have been developed to minimize the lower resistance. The first method is to have a density gradient of pores in the membrane. The pore size of the upper part is very small, the pore size of the lower part is adjusted to be larger, so that the upper part has a dense structure and the lower part has a small transmission resistance. The second method is to increase the concentration of the polymer solution in the upper portion and lower the concentration of the polymer solution in the lower portion by adding an organic solvent having a low surface tension and high volatility.

The prior art is described in the following patents. In US Pat. No. 4,230,463, a gas separation membrane was prepared using a coating on the surface of a porous membrane. US Pat. No. 4,484,935 consists of a coating layer composed of a combination of a PDMS and a crosslinking agent having a modified silicon-containing monomer and a porous asymmetric membrane. Component gas separation membranes are described. In addition, US Pat. No. 4,728,346 treats and coats the membrane surface with an aromatic permeation regulator to improve the selectivity of the gas separation membrane.

However, the coating and curing process of the film surface is discontinuous and involves additional cost and complexity. The forced convection method described below is described in the following patents and articles. In US Pat. No. 4,902,422, a gas separation flat membrane cast from a four-component polymer solution containing a volatile solvent and a nonsolvent was prepared using a convection evaporation process without an additional coating process. The oxygen / nitrogen selectivity of this asymmetric flat membrane ranges from 5.0 to 6.5. See also, Pinnau et al., J. Memb. Sci., 88, 1-19 (1994)] applied a forced convection process to produce a hollow fiber membrane to prepare a hollow fiber membrane for gas separation having a selectivity of 6.5 without coating and curing process. However, manufacturing a hollow fiber membrane without a process of sealing such additional defects is quite difficult because of demanding manufacturing techniques such as a convection evaporation process.

The above-described known techniques are capable of producing a gas separation membrane having excellent coating properties and excellent selectivity, but have a disadvantage in that the overall resistance is high even if the bottom resistance is small because the permeation resistance of the top coating layer is large.

The present invention has been invented to solve the problems of the conventional patent as described above, the present invention is to provide a gas separation membrane manufacturing method of the lower resistance is minimized.

Another object of the present invention is to provide a gas separation membrane manufactured by a gas separation membrane manufacturing method of which lower resistance is minimized, and a module using the gas separation membrane.

In order to achieve the above object,

The present invention

(1) 25-40 weight% of membrane-like polymers, (B) 30-65 weight% of polymer solvents, (C) 1-15 weight% of polymers or oligomer additives; And (D) a first step of spinning a dope solution containing 5 to 15% by weight poor solvent additive;

(2) a second step of solidifying the spun dope solution to form a hollow fiber;

(3) a third step of washing and removing the solidified hollow fiber solvent and poor solvent additive, polymer or oligomer additive;

(4) a fourth step of replacing the coagulating solution in the hollow fiber with an organic solvent; And

(5) The fifth step of drying the hollow fiber substituted with an organic solvent

It provides a hollow fiber gas separation membrane manufacturing method comprising a.

In another aspect, the present invention provides a hollow fiber gas separation membrane prepared by the above method.

In another aspect, the present invention provides a hollow fiber module comprising the gas separation membrane.

In addition, the present invention

(1) 25-40 weight% of membrane-like polymers, (B) 30-65 weight% of polymer solvents, (C) 1-15 weight% of polymers or oligomer additives; And (D) a first step of casting a dope solution containing 5-15 wt% of the poor solvent additive on the nonwoven fabric to produce a flat membrane;

(2) a second step of solidifying the flat membrane;

(3) washing and removing the solvent and the polymer or oligomer additive in the solidified flat membrane

The third step;

(4) a fourth step of replacing the coagulating solution in the flat membrane with an organic solvent; And

(5) a fifth step of drying the flat membrane substituted with an organic solvent

It provides a flat film manufacturing method comprising a.

The present invention also provides a flat membrane prepared by the above method.

The present invention also provides a flat membrane module comprising the flat membrane.

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

After repeating research to minimize the lower resistance of the prepared gas separation membrane, a polymer or oligomer additive is mixed in a dope solution to spin hollow fiber, and the dope solution is solidified by solidifying the dope solution to form a hollow fiber. Removing the polymer to oligomer additives inside the yarn was found to minimize the bottom resistance of the prepared gas separation membrane and came to the present invention.

Gas separation membrane manufacturing method of the present invention is largely divided into two methods of manufacturing hollow fiber and flat membrane. Hollow fiber manufacturing method and flat film manufacturing method is divided into the initial spinning step, casting step, respectively, after that solidification, washing, replacement, drying step is the same, so the description of the hollow fiber and flat membrane manufacturing method will be described together.

Gas separation membrane manufacturing method of the present invention proceeds in five steps as follows.

First, (1) 25 to 40% by weight of the membrane-like polymer, (B) 30 to 65% by weight of the polymer solvent, (C) 1 to 15% by weight of the polymer or oligomer additive; And (D) a first step of spinning a dope solution containing 5 to 15% by weight poor solvent additive;

Second, (2) a second step of solidifying the spun dope solution to form a hollow fiber;

Third, (3) solvents and poor solvent additives in solidified hollow fiber, polymers or oligomers

A third step of washing and removing the additives;

Fourth, (4) a fourth step of replacing the coagulating solution in the hollow fiber with an organic solvent; And

Fifth, (5) the fifth step of drying the hollow fiber substituted with an organic solvent.

In order to prepare a gas separation membrane with a minimum lower resistance, the content of each component constituting the dope solution is 25 to 40% by weight of the polymer material, 30 to 65% by weight of the polymer solvent, 1 to 15% by weight of the polymer or oligomer additive, and poor solvent. It is necessary to finely adjust the composition of the dope solution with 5 to 15% by weight of the additive. The reason for this is that the dope solution is thermodynamically very unstable, so if the content control is out of the above range, the phase separation is already progressed in the dope solution phase, which makes it impossible to manufacture a gas separation membrane having a lower resistance. In addition, when the temperature of the dope solution is increased, the thermodynamic stability of the dope solution may be higher, and the mixed phase may be stabilized.

An ideal gas separation membrane has a high permeability and does not lose its performance at high temperatures and pressures. In general, polymer materials with high permeability have low selectivity and polymer materials with low permeability have high selectivity. It is very important to select a film forming material (membrane polymer) constituting the gas separation membrane.

The polymer material (membrane polymer), which is an asymmetric gas separation membrane-forming material in general membrane production, is a natural or synthetic polymer material having useful gas separation performance, and is dissolved in a strong solvent to form a uniform solution. By immersing in the coagulant solution that is a non-solvent for the polymer material to form a flat membrane or hollow fiber membrane.

The membrane polymer used in the asymmetric membrane of the present invention is selected in consideration of the thermal, mechanical and chemical durability of the constituent material, and in particular, it is preferable to have a permeability to at least one gas of the gas mixture, in particular polysulfone, poly It is more preferable to use a mead, a polyamide, or a mixture thereof as a film polymer.

The content of the membrane polymer in the dope solution is preferably 25 to 40% by weight of the total dope solution. If the content of the membrane polymer is less than 25% by weight, the pore size of the prepared gas separation membrane is increased, so that the selectivity is reduced, and if it is more than 40% by weight, it is difficult to prepare a uniform phase dope solution.

In addition, as the solvent for the membrane polymer, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N-dimethylsulfoxide, or a mixture thereof is preferable. -Methylpyrrolidone is most preferred.

The content of the solvent in the dope solution is preferably 30 to 65% by weight of the total dope solution. If the content of the solvent is less than 30% by weight, the dope solution is not uniform, and if it exceeds 65% by weight, the selectivity is lowered.

In addition, as the polymer or oligomer additive added to minimize the bottom resistance of the gas separation membrane prepared in the present invention, polyvinylpyrrolidone, polyethylene glycol, polyoxyylene alkyl ester, octylphenol polyethylene glycol ether, or a mixture thereof may be used. desirable. Such polymer or oligomer additives serve to promote phase separation of the dope solution.

The content of the polymer or oligomer additive is preferably 1 to 15% by weight in the dope solution. If the content of the polymer or oligomer additive is less than 1% by weight, it is impossible to prepare a gas separation membrane having a lower resistance, and if the content exceeds 15% by weight, the selectivity of the membrane may be lowered.

In addition, the poor solvent additive added as an essential component of the dope solution of the present invention is an organic solvent, tetrahydrofuran, ethanol, trichloroethane, 2-methyl-1-butanol, 2-methyl-2-butanol, 2 -Pentanol or a mixture thereof is preferred.

The content of such a poor solvent additive is preferably 5 to 15% by weight in the dope solution. The poor solvent has an effect of suppressing defects on the surface of the membrane, and if the content of the additive is less than 5% by weight, there is a problem that the effect of suppressing defects is lowered, and if the content is more than 15% by weight, it is difficult to obtain a uniform dope solution. have.

Since the composition of the dope solution of the present invention is preferably located at the interface between the single phase and the separated phase, it is important to control the concentration of each component in the dope solution so that the mixed solution is close to the phase separation boundary.

The spinning or casting process for producing a gas separation membrane such as hollow fiber or flat membrane from the dope solution described above is preferably performed at a high temperature. Therefore, in the present invention, it is preferable to proceed in a state in which the temperature of the spinnerette or the casting knife is heated close to the boiling point of the volatile additive. At this time, the dope solution from the spinnerette or casting knife is brought into contact with the atmosphere, and the volatile solvent / poor solvent additive is evaporated in the hot dope solution. The existing technology forms a dense layer on the surface by forced convection at this stage. However, in the present invention, since the dope solution is exposed to the air at a temperature close to the boiling point of the solvent / poor solvent additive, the evaporation of the solvent / poor solvent additive is prevented. Is promoted. Also, in the step after spinning or casting, the dope solution is precipitated in a low temperature nonsolvent coagulant by lowering the temperature from room temperature to proceed with a quenching process. This quenching process accelerates the phase separation rate of the dope solution, thereby suppressing the formation of interconnected pores of the selective separation layer by nucleation and growth mechanisms on the surface of the solidified gas separation membrane.

The hollow fiber gas separation membrane manufacturing method of the present invention utilized the method described in the Republic of Korea Patent Application No. 2000-0048823 patented by the inventor.

Each component of the dope solution, that is, a membrane polymer, a solvent, a polymer or oligomer additive, and a poor solvent additive is made into a uniform solution using a closed reactor, and the uniform dope solution is allowed to stand at room temperature and reduced pressure for 24 hours to form bubbles in the solution. After the removal was spun through a spinnerette (spinerrette). At this time, the spinnerette has a double nozzle structure, and the dope solution is discharged through the outer nozzle of the double nozzle, and the inside of the double spinnerette discharges the internal coagulant at a flow rate of 1 to 2 ml / min. Manufacture hollow fiber. The inner diameter of the outer nozzle of the double nozzle is 0.5 to 0.8 mm, and the inner and outer diameters of the inner nozzle of the double nozzle are 0.2 to 0.3 mm and 0.4 to 0.6 mm, respectively.

The spinning solution is first coagulated in the hollow fiber before being precipitated in the primary coagulant liquid non-solvent for the polymer material (membrane polymer). At this time, at the surface where the internal coagulating solution radiated through the double nozzle and the dope solution are contacted with each other, gelling is formed by the interdiffusion action of the solvent, the additive in the dope solution, and the internal coagulant to form a dense separation layer having relatively dense and very small pores. Under the separation layer, a porous lower structure layer is formed due to the continuous phase separation between the internal coagulation solution and the dope solution, and then precipitates in the external coagulation solution.

Subsequently, the phase separation process that occurs due to contact with the coagulating liquid inside the hollow fiber also occurs on the outer surface of the hollow fiber precipitated in the primary coagulating liquid. The hollow fiber membrane subjected to the spinning and coagulation step is then made into a membrane consisting of a dense separation layer without defects on the outer surface and a porous substructure layer having pores through a washing step, a substitution step and a drying step.

In the case of the flat membrane, the polymer mixed solution is cast on the nonwoven fabric, and then precipitated in a coagulant solution, which is a non-solvent in the polymer material, to undergo a coagulation step.

In the case of the hollow fiber membrane for gas separation manufactured according to the present invention, the outer diameter is about 0.3-0.5 mm, the inner diameter is about 0.25 mm, and the thickness of the dense separation layer having the resolution is about 0.1 μm.

The method of the present invention will be described in more detail by the process. First, in the coagulation step, gelation occurs relatively quickly between the coagulation solution and the solvent / additive mixture on the surface where the coagulation solution and the dope solution come into contact with each other during the preparation of the separator. Using a dope solution prepared to facilitate this and increasing the difference between the temperature of the dope solution and the coagulation bath proceeds with very rapid phase separation, thereby forming a separator consisting of a dense separation layer and a porous structure layer including pores.

The coagulating solution should be non-solvent for the polymer material and should be compatible with all components constituting the polymer mixed solution except for the polymer. As the coagulating liquid used in the present invention, alcohols such as water, methanol, ethanol, isopropyl alcohol, or a mixture of water and alcohols are preferable, and water is more preferable.

The gas separation membrane solidified by spinning or casting as described above is subjected to a washing step to easily remove a mixture of a solvent and an additive remaining in the inside and the surface, a coagulating solution, and the like, which is performed with running water for 1 to 10 days. It is preferable.

At this time, the polymer or oligomer additive incorporated in the hollow fiber already formed needs to be removed in the washing step. The polymer or oligomer additive in the coagulated polymer membrane material (membrane polymer) may be dissolved in water or alcohols to improve connectivity to the air space under the hollow fiber.

The remaining water after the washing step must be treated with a substitution solution such as methanol, ethanol, 2-propanol, hexane or mixtures thereof. Of the above substituents, methanol is preferred.

In the drying step after washing, the substitution liquid completely wetted in small pores or defects on the surface of the membrane has a surface tension equal to or less than that of the polymer material, which is a film-forming substance, and thus the volatilization volatilization is applied to the capillary pressure. This completely eliminates small pores or defects in the separation layer.

It is preferable that the separation membrane having such a substitution process is dried at 50 to 100 ° C. under vacuum for 3 to 24 hours.

As described above, the present invention promotes phase separation of the dope solution by the polymer or oligomer additive to control the pore or defect size in the dense separation layer, washing step for removing the polymer or oligomer additive in the membrane, It is possible to manufacture a separation membrane having a low permeation resistance through a substitution step of replacing a liquid having a small surface tension with pores in the membrane and a drying step.

Hollow fiber gas separation membrane or flat membrane prepared through the gas separation membrane manufacturing method of the present invention described above is also applicable as a gas separation module, the application method is possible by a conventionally known method, so the detailed description thereof will be omitted. Shall be.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples and comparative examples are described to explain the present invention in more detail, but the content of the present invention is not limited to the following examples and comparative examples.

Example 1

Add 30 wt% of polymer polyetherimide (GE plastic, Ultem ^® ) to 50 wt% of N-methylpyrrolidone solvent based on the total amount of the mixture 100, 10, 5 wt% of tetrahydrofuran, Triton 10, 15 weight% of -X-100 was added and mixed to prepare a uniform solution. Bubbles in the prepared uniform spinning solution were removed at room temperature and reduced pressure for 24 hours, and foreign materials were removed using a 60 μm filter. It was then spun at 60 ° C. At this time, the air gap was 10cm, double spinnerets were used, and the internal coagulating solution was spun with water at room temperature. After winding and cutting, the mixture was washed in running water for 2 days to remove the remaining mixture of solvent and additives. Subsequently, it was immersed in methanol for 3 hours or more to replace the water present in the dense separation layer, and again immersed in hexane (n-hexane) for 3 hours to replace methanol with hexane, and then dried at 70 ° C. in vacuo for 3 hours. A hollow fiber membrane was prepared.

The performance of the prepared hollow fiber membrane was 99.9% nitrogen, respectively, and applied to three identical hollow fiber modules under 5 atm to measure the average nitrogen gas permeability. Each hollow fiber module included ten hollow fiber membranes and gas permeability was measured using a mass flow meter. Gas permeation unit was used (Gas Permeation Unit, 10-6 × cm ³ / cm ² sec cm Hg). The results are shown in Table 1.

Weight% of Triton-X-100 Nitrogen permeability (Q, GPU), 25 ℃ 10 15 15 150

Example 2

Based on the total amount of the mixture, 37 wt% of polyethersulfone (manufacturer: Sumitomo) as a polymer was gradually added to 43 wt% of N-methylpyrrolidone solvent, and 10, 5 wt% of tetrahydrofuran and polyvinylpyrrole as additives. The same procedure as in Example 1 was conducted except that 10 wt% and 15 wt% of ralidone were added and mixed to prepare a uniform solution. Performance evaluation results of the prepared membrane are shown in Table 2 below.

% By weight of polyvinylpyrrolidone Nitrogen permeability (Q, GPU), 25 ℃ 10 30 15 220

Example 3

The hollow fiber manufactured according to Examples 1 and 2 was subjected to the dehumidification performance test of the compressed air using the apparatus as shown in FIG. 1. Dehumidification performance was measured based on the process shown in FIG. 1 and compressed air was used as a gas containing moisture. The dehumidification process of Figure 1 proceeds as follows. As the gas containing water is supplied to the supply gas inlet 100 of the dehumidifying hollow fiber membrane module 10 and the gas comes into contact with the surface of the hollow fiber membrane, the moisture quickly penetrates the membrane and at the same time, a dry body located at one end of the module. Dry gas is discharged to the outlet 200. At this time, the wet gas containing a large amount of moisture that has passed through the membrane is discharged into the atmosphere through the wet gas discharge unit 300. In addition, by installing a pressure control valve 400 in the drying body outlet 200 to adjust the flow rate of the gas discharged from the drying body outlet 200 to maintain the dehumidification performance of the pressure control valve 400 By adjusting the purge flow control valve 500 located at the other end to allow a portion of the dry gas discharged from the dry gas outlet 200 to flow into the purge gas inlet 600 of the module to remove the water generated on the membrane surface Thereafter, it is discharged into the atmosphere through the wet gas discharge unit 300. In the dehumidification experiment, air having an air temperature of 20 ° C., a dew point temperature of −5 ° C., and a pressure of 5 kg / cm 2 is supplied to the supply gas inlet part 100, and is supplied to the dryer outlet part 200 located on one side of the dehumidifying membrane module. In the process of discharging it is possible to control the dehumidification performance by reducing the discharge flow rate by adjusting the pressure control valve 400 located at the top of one side. Dew point temperature was measured using a Model DSP-Rm (UK Alpha moisture systems) dew point meter and the results are shown in Table 3 below.

Weight percent of additive Supply flow rate (L / min) Treatment flow rate (L / min) % Recovery Treatment dew point (℃) Example 1 10 40 28 70 -35 15 40 28 70 -42 Example 2 10 40 28 70 -37 15 40 28 70 -44

Comparative Example 1

10, 5% by weight of tetrahydrofuran as an additive while gradually adding 30% by weight of polymer polyetherimide (GE plastic, Ultem ^® ) to 60, 65% by weight of N-methylpyrrolidone solvent based on the total amount of the mixture 100 Was carried out in the same manner as in Examples 1 and 3, except that a uniform solution was prepared by adding and mixing. Performance evaluation results of the prepared membrane are shown in Table 4 below.

Comparative Example 2

Add 10, 5% by weight of tetrahydrofuran as an additive while slowly adding 37% by weight of polymer polyethersulfone (manufactured by Sumitomo) to 53, 58% by weight of N-methylpyrrolidone solvent based on the total amount of the mixture 100 It was performed in the same manner as in Examples 1 and 3, except that a uniform solution was prepared by mixing. Performance evaluation results of the prepared membrane are shown in Table 4 below.

Nitrogen permeability (Q, GPU), 25 ℃ Treatment dew point (℃) Comparative Example 1 One -31 Comparative Example 2 10 -34

As described above, in the case of the general gas separation membrane as in Comparative Example 1, the lower resistance of the membrane is high, so the permeability of nitrogen is low, and in the case of the separation membrane of the lower permeation resistance of Examples 1 and 2 of the present invention, the nitrogen permeability And the treatment dew point, which is a performance of the dehumidification permeation experiment, was excellent.

As described above, it is possible to minimize the lower permeation resistance of the separator by removing the additive in the washing step of the hollow fiber, including a polymer to oligomer additive that is easy to remove during the preparation of the dope solution for the hollow fiber membrane. . The membrane thus prepared is applicable to air separation, membrane dehumidification process, volatile organic sulfide separation process and the like.

As described above, the gas separation membrane of the present invention promotes phase separation of the dope solution by the polymer or oligomer additive to control the size of pores or defects in the dense separation layer, and washes to remove the polymer or oligomer additive in the membrane. Since the step, the substitution step of replacing the liquid with a small surface tension to the pores in the membrane, and the drying step is produced through the lower permeation resistance can be preferably used as a gas separation membrane.

Claims (14)

(1) 25-40 weight% of membrane-like polymers, (B) 30-65 weight% of polymer solvents, (C) 1-15 weight% of polymers or oligomer additives; And (D) a first step of spinning a dope solution containing 5 to 15% by weight poor solvent additive; (2) a second step of solidifying the spun dope solution to form a hollow fiber; (3) a third step of washing and removing the solvent and the poor solvent additive, the polymer or oligomer additive in the solidified hollow fiber; (4) a fourth step of replacing the coagulating solution in the hollow fiber with an organic solvent; And (5) The fifth step of drying the hollow fiber substituted with an organic solvent Hollow fiber gas separation membrane manufacturing method comprising a. The method of claim 1, The membrane polymer is a hollow fiber gas separation membrane manufacturing method, characterized in that selected from the group consisting of polyethersulfone, polysulfone, polyetherimide and polyimide. The method of claim 1, The polymer solvent is N-methylpyrrolidone, N, N- dimethylformamide, N, N- dimethylacetamide and N- dimethyl sulfoxide, characterized in that the hollow fiber gas separation membrane manufacturing method. The method of claim 1, The polymer or oligomer additive is polyvinylpyrrolidone, polyethylene glycol, polyoxyylene alkyl ester and octyl phenol polyethylene glycol ether, characterized in that the hollow fiber gas separation membrane manufacturing method characterized in that selected from the group consisting of. The method of claim 1, The poor solvent additive is a hollow fiber gas separation membrane manufacturing method, characterized in that selected from the group consisting of tetrahydrofuran, trichloroethane, 2-methyl-1-butanol, 2-methyl-2-butanol and 2-pentanol. The method of claim 1, The coagulating solution used in the second step is a hollow fiber gas separation membrane manufacturing method, characterized in that selected from the group consisting of water, methanol, ethanol and isopropyl alcohol. The method of claim 1, The third step of washing is hollow fiber gas separation membrane manufacturing method, characterized in that performed in running water for 1 to 10 days. The method of claim 1, Substituent used in the fourth step is a hollow fiber gas separation membrane manufacturing method, characterized in that selected from the group consisting of methanol, ethanol, 2-propanol and hexane. The method of claim 1, Drying of the fifth step is a hollow fiber gas separation membrane manufacturing method, characterized in that proceeds for 3 to 24 hours at 50 ~ 100 ℃, vacuum. A hollow fiber gas separation membrane prepared by the method according to any one of claims 1 to 9. Hollow fiber module comprising a gas separation membrane of claim 10. (1) 25-40 weight% of membrane-like polymers, (B) 30-65 weight% of polymer solvents, (C) 1-15 weight% of polymers or oligomer additives; And (D) a first step of casting a dope solution containing 5-15 wt% of the poor solvent additive on the nonwoven fabric to produce a flat membrane; (2) a second step of solidifying the flat membrane; (3) a third step of washing and removing the solvent and the poor solvent additive, the polymer or oligomer additive in the solidified flat membrane; (4) a fourth step of replacing the coagulating solution in the flat membrane with an organic solvent; And (5) a fifth step of drying the flat membrane substituted with an organic solvent Flat membrane manufacturing method comprising a. Flat membrane prepared by the method according to claim 12. A membrane module comprising the membrane of claim 13.

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