KR20210098374A - coating solution for hollow fiber membrane, composite membrane using the same, preparation method thereof and carbon dioxide separation membrane comprising the same - Google Patents

Abstract

The present invention relates to a composition for coating a hollow fiber membrane, a composite hollow fiber membrane manufactured therefrom, a method for manufacturing the same, and a carbon dioxide separation membrane comprising the same. More specifically, the present invention relates to a composite hollow fiber membrane, to a method for manufacturing the same, and to a technology applied as a carbon dioxide separation membrane with excellent permeability and selectivity to carbon dioxide/oxygen, wherein the composite hollow fiber membrane is manufactured using a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (polyethyleneglycol-POSS, PEG-POSS) and polyether polyamide block copolymer (PEBAX).

Description

A composition for coating a hollow fiber membrane, a composite hollow fiber membrane prepared therefrom, a manufacturing method thereof, and a carbon dioxide separation membrane comprising the same

The present invention relates to a composition for coating a hollow fiber membrane, a composite hollow fiber membrane prepared therefrom, a method for producing the same, and a carbon dioxide separation membrane comprising the same, and more particularly, to a polyethylene glycol-polyhedral oligomeric silsesquioxane (polyethyleneglycol-POSS). , PEG-POSS) and polyether polyamide block copolymer (PEBAX) to prepare a composition for coating a hollow fiber membrane, using the composite hollow fiber membrane, a manufacturing method thereof, and carbon dioxide with excellent permeability and selectivity to carbon dioxide/oxygen It relates to a technology applied as a separator.

In accordance with the occurrence of climate change due to global warming, efforts are being made to secure measures to reduce greenhouse gases worldwide and to create new growth engines based on this and to preoccupy the global market. In general, as technological measures to cope with climate change, (i) energy efficiency improvement, (ii) replacement with low-carbon fuels such as nuclear and renewable energy, and (iii) CO ₂ capture and storage technology have been used.

In general, carbon dioxide capture and storage (CCS; Carbon Dioxide Capture & Storage) technology is a technology for isolating carbon dioxide emitted from mass emission sources such as power plants, steel and cement factories due to the use of fossil fuels from the atmosphere. Among the many technologies for capturing carbon dioxide, the technology using a separator is a technology that is growing rapidly due to its simple design and low energy consumption, which reduces operating costs.

In order for such a gas separation membrane to selectively separate and concentrate gas, the structure of the separation membrane should generally be an asymmetric structure consisting of a dense selective separation layer on the surface of the membrane and a porous support having a minimum permeation resistance at the bottom of the membrane. The selective separation capability of gas, which is a characteristic of a gas separation membrane, is determined by the structure of the separation layer, and the permeation amount of the selectively separated gas depends on the thickness of the separation layer and the degree of porosity of the porous support, which is the underlying structure of the asymmetric membrane. And in order to selectively separate the mixed gas, there should be no defects on the surface of the separation layer, and the pore size should be 5 Å or less. In addition, in order to obtain high gas permeability, the thickness of the separation layer should be as thin as possible, since gas permeability is inversely proportional to the effective film thickness. In addition, in order to minimize the resistance to the gas flow selectively passing through the separation layer, it is advantageous to have a porous structure to be the underlying structure of the asymmetric membrane.

Therefore, a dense selective separation layer of a thin film is formed by the traditional phase separation method and a single-layer hollow fiber membrane with an asymmetric structure having a porous structure at the bottom has been continuously developed. there is.

As a material for the selective separation layer (coating layer), polyimide having excellent mechanical and thermal properties, chemical resistance and relatively good separation performance has been studied, but it has low permeability and separation coefficient, so it is used for gas separation in large-scale equipment industry. Inappropriate.

On the other hand, polyethylene glycol has excellent selectivity due to its high affinity for carbon dioxide, and mechanical properties can be improved through modification such as blending, copolymerization, and crosslinking with polymers such as polysulfone, polyimide, and polyamide having excellent physical properties. Although it has been studied that excellent carbon dioxide separation characteristics can be expected while maintaining it, there is a disadvantage in that the permeability is rather lowered due to the random structure.

In addition, a coating solution using a combination of fluoropolyimide/polyethylene sulfone has been developed, but this has a disadvantage in that the thickness of the coating layer is too thick and oxygen permeability is lowered.

Therefore, the present inventors focused on the ability to prepare a composition for coating a hollow fiber membrane that has excellent adhesion to the hollow fiber membrane, reduces the shrinkage of the hollow fiber membrane, and can improve the permeability and selectivity to carbon dioxide. came to completion.

Patent Literature 1. Republic of Korea Patent Publication No. 10-1752954

The present invention was devised in consideration of the above problems, and an object of the present invention relates to a composition for coating a hollow fiber membrane capable of improving permeability and selectivity to carbon dioxide.

Another object of the present invention is to provide a composite hollow fiber membrane with improved permeability and selectivity for carbon dioxide prepared therefrom, a method for manufacturing the same, and an excellent carbon dioxide separation membrane using the same.

The present invention for achieving the above object is polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533. A composition for coating a hollow fiber membrane provides

The polyhedral oligomeric silsesquioxane (POSS) may be 85 to 95 wt% based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS).

The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 may be 1: 0.5 to 1.5.

The composition for coating the hollow fiber membrane may further include a solvent, and the solvent may be isopropanol.

80 to 99 wt% of the solvent may be included based on 1 to 10 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 .

In addition, the present invention is a hollow fiber membrane; and a coating layer formed on the hollow fiber membrane, the coating layer comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX); provides a composite hollow fiber membrane comprising .

A polyethylene layer may be further included between the hollow fiber membrane and the coating layer.

In addition, the present invention provides a carbon dioxide separation membrane comprising the composite hollow fiber membrane.

In addition, the present invention comprises the steps of (A) impregnating the hollow fiber membrane in a polyethylene glycol solution; (B) pretreatment by drying the hollow fiber membrane of step (A) at a temperature of 10 to 50 °C; and (C) coating a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 on one surface of the pretreated used sand membrane. It provides a method of manufacturing a composite hollow fiber membrane comprising a;

The polyhedral oligomeric silsesquioxane (POSS) may be 85 to 95 wt% based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS).

The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 may be 1: 0.5 to 1.5.

The composition for coating the hollow fiber membrane may further include a solvent, and the solvent may be isopropanol.

95 to 97 wt% of the solvent may be included based on 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 .

In step (C), the coating temperature may be 50 to 70 °C.

In step (C), the coating time may be 50 to 100 seconds.

In step (C), the number of coatings may be 1 to 2 times.

According to the present invention, a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (polyethyleneglycol-POSS, PEG-POSS) and polyether polyamide block copolymer (PEBAX) is prepared, and the A composite hollow fiber membrane having excellent permeability and selectivity to carbon dioxide can be manufactured by using it, which can be applied as a carbon dioxide separation membrane.

1A is an image showing a process of manufacturing a composite hollow fiber membrane according to the present invention.
Figure 1b is a laboratory-scale composite hollow fiber membrane module (Lab scale module) manufactured using the composition for coating a hollow fiber membrane according to the present invention.
1c is a scale-up composite hollow fiber membrane module (scale up module) manufactured using the composition for coating a hollow fiber membrane according to the present invention.
2 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Comparative Examples 1 to 4 of the present invention [EtOH/ H2O is Comparative Example 1, EtOH is Comparative Example 2, IPA is Comparative Example 3, and BuOH is a composite hollow fiber membrane prepared using Comparative Example 4].
3 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Comparative Examples 5 to 8 of the present invention [IPA is Comparative Example 5, IPA/BuOH is Comparative Example 6, BuOH is Comparative Example 7, and EtOH is a composite hollow fiber membrane prepared using Comparative Example 8].
4 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Examples 3 to 6 of the present invention [IPA is Example 3, IPA/BuOH is Example 4, BuOH is Example 5, EtOH is a composite hollow fiber membrane prepared using Example 6]. At this time, IPA means Isopropanol, Buthanol, IPA/BuOH means Isopropanol-Butanol co-solvent, BuOH means Butanol, EtOH means Ethanol and EtOH/H ₂ O means Ethanol-H 2 O co-solvent.
5 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating the hollow fiber membranes of Example 3, Comparative Example 1, and Comparative Example 5 of the present invention; It is a graph shown [POSS/2533 is Comparative Example 5, POSS/3533 is Example 3, and POSS/1657 is Comparative Example 1. POSS-PEG is a control, a composite hollow fiber membrane (solvent: methanol) was prepared using the POSS90wt prepared in Preparation Example 3.]
6 shows the gas permeability (nitrogen, It is a graph showing the selectivity of carbon dioxide to oxygen and carbon dioxide) and oxygen.
7 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 10 to 14 of the present invention [20 ° C is Example 10, 40 ° C is Example 11, 60°C is Example 12, 80°C is Example 13, 100°C is Example 14].
8 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 15 to 18 of the present invention [30 is Examples 15 and 60 are Examples 12 and 120 are Examples 16, 180 is Example 17, 240 is Example 18].
9 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 19 to 21 of the present invention [0.5 is Examples 19, 1 is Examples 20 and 3 are Examples 12 and 5 are Example 21].
10 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 22 to 24 of the present invention [0 is Examples 22, 1 is Examples 12 and 2 are Examples 23 and 3 are Example 24].
11 is a graph showing the results of analyzing the gas permeability and gas selectivity for a single gas of the composite hollow fiber membrane module of Example 12 and the composite hollow fiber membrane module of Example 23;
12 is a graph showing the result of analyzing the gas permeability to the mixed gas of the composite hollow fiber membrane module of Example 23.

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

The present invention provides a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533.

By coating the surface of the conventional hollow fiber membrane, carbon dioxide permeability and selectivity can be improved. In particular, the composition for coating a hollow fiber membrane according to the present invention has significantly superior carbon dioxide permeability and selectivity by 1.3 to 2 times or more compared to the case of using polyethylene glycol-polyhedral oligomeric silsesquioxane or polyether polyamide block copolymer alone. has

Polyether polyamide block copolymers (PEBAX) include PEBAX 1657, PEBAX 2533, and PEBAX 3533, and when polyether polyamide block copolymer (PEBAX) is used alone as a composition for hollow fiber membrane coating, carbon dioxide permeability is PEBAX 2533 It was confirmed that PEBAX 1657 had the highest carbon dioxide selectivity. However, when coating the hollow fiber membrane, it can be uniformly mixed with polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) to form a coating layer of uniform thickness, and the carbon dioxide/oxygen selectivity and carbon dioxide permeability of the hollow fiber membrane can be improved. It has been confirmed that it is the PEBAX 3533 that can be improved overall.

The polyhedral oligomeric silsesquioxane is 45 to 99% by weight, preferably 70 to 95% by weight, more preferably 80 to 95% by weight based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane It may be % by weight, and even more preferably 85 to 95% by weight. When the content of the polyhedral oligomeric silsesquioxane is out of 45 to 99 wt%, carbon dioxide selectivity or gas permeability may be significantly reduced. In particular, when the polyhedral oligomeric silsesquioxane (POSS) is less than 85% by weight based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS), the carbon dioxide/oxygen selectivity is 1.3 There may be a problem of lowering more than twice, and if it exceeds 95% by weight, overall mechanical properties may be reduced.

The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 is 1: 0.5 to 1.5, preferably 1: 0.7 to 1.3, more preferably preferably 1: 0.9 to 1.1. When the weight ratio is out of 1:0.5 to 1.5, the adhesive force with the hollow fiber membrane may not be sufficiently secured, and thus there may be a problem in that the shrinkage of the hollow fiber membrane cannot be sufficiently suppressed.

The composition for coating the hollow fiber membrane may further include a solvent, and the solvent may be at least one selected from the group consisting of isopropanol, butanol, ethanol and distilled water, and most preferably isopropanol. This can be confirmed through Experimental Example 2.

It is preferable to include 95 to 97 wt% of the solvent based on 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 and, more preferably, 97% by weight of the solvent based on 3% by weight of the mixture. In the case of the above range, the selectivity of carbon dioxide to oxygen of the hollow fiber membrane can be significantly improved by two times or more.

In addition, the present invention is a hollow fiber membrane; and a coating layer formed on the hollow fiber membrane, the coating layer comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533; providing a composite hollow fiber membrane comprising do.

A polyethylene glycol (PEG) layer may be further included between the hollow fiber membrane and the coating layer. The additive polyethylene glycol layer can improve the transparency of the hollow fiber membrane. Furthermore, when the coating layer is formed on the surface of the hollow fiber membrane, carbon dioxide permeability and carbon dioxide selectivity to oxygen can be further improved. However, in the coating layer, the polyether polyamide block copolymer (PEBAX) has an improvement effect only when it is 3533, and the carbon dioxide selectivity to oxygen is rather lowered for 1657 and 2533.

In addition, the present invention provides a carbon dioxide separation membrane comprising the composite hollow fiber membrane according to the present invention.

In addition, the present invention comprises the steps of (A) impregnating the hollow fiber membrane in a polyethylene glycol (PEG) solution;

(B) pretreatment by drying the hollow fiber membrane of step (A) at a temperature of 10 to 50 °C; and

(C) Coating a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 on one surface of the pretreated used sand membrane It provides a method for manufacturing a composite hollow fiber membrane comprising;

First, (A) the hollow fiber membrane is impregnated in a polyethylene glycol (PEG) solution.

Specifically, the polyethylene glycol (PEG) solution in step (A) may have a concentration of 0.5 to 10 wt%. It is preferable to use the polyethylene glycol having an average molecular weight of 100 to 400. When the concentration of the polyethylene glycol (PEG) solution is high or low, the uniformity of the coating does not show uniform performance of the membrane. can cause

Next, in step (B), after step (A), the hollow fiber membrane of step (A) is dried at 10 to 50° C. or higher and pre-treated. At this time, it is preferably carried out for 1 to 10 hours.

Finally (C) a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 on one surface of the pre-treated used yarn coating

The coating of step (C) is brush coating, dip coating, bar coating, spin coating, spray coating, slot-die coating coating) or roll-to-roll coating, preferably, dip coating.

Polyether polyamide block copolymers (PEBAX) include PEBAX 1657, PEBAX 2533, and PEBAX 3533, and when polyether polyamide block copolymer (PEBAX) is used alone as a composition for hollow fiber membrane coating, carbon dioxide permeability is PEBAX 2533 It was confirmed that PEBAX 1657 had the highest carbon dioxide selectivity. However, when coating the hollow fiber membrane, it can be uniformly mixed with polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) to form a coating layer of uniform thickness, and the carbon dioxide/oxygen selectivity and carbon dioxide permeability of the hollow fiber membrane can be improved. It has been confirmed that it is the PEBAX 3533 that can be improved overall.

The polyhedral oligomeric silsesquioxane is 45 to 99% by weight, preferably 70 to 95% by weight, more preferably 80 to 95% by weight based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane It may be % by weight, and even more preferably 85 to 95% by weight. When the content of the polyhedral oligomeric silsesquioxane is out of 45 to 99 wt%, carbon dioxide selectivity or gas permeability may be significantly reduced. In particular, when the polyhedral oligomeric silsesquioxane (POSS) is less than 85% by weight based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS), the carbon dioxide/oxygen selectivity is 1.3 There may be a problem of lowering more than twice, and if it exceeds 95% by weight, overall mechanical properties may be reduced.

The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 is 1: 0.5 to 1.5, preferably 1: 0.7 to 1.3, more preferably preferably 1: 0.9 to 1.1. When the weight ratio is out of 1:0.5 to 1.5, the adhesive force with the hollow fiber membrane may not be sufficiently secured, and thus there may be a problem in that the shrinkage of the hollow fiber membrane cannot be sufficiently suppressed.

The composition for coating the hollow fiber membrane may further include a solvent, and the solvent may be at least one selected from the group consisting of isopropanol, butanol, ethanol and distilled water, and most preferably isopropanol. This can be confirmed through Experimental Example 2.

It is preferable to include 95 to 97 wt% of the solvent based on 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 and, more preferably, 97% by weight of the solvent based on 3% by weight of the mixture. In the case of the above range, the selectivity of carbon dioxide to oxygen of the hollow fiber membrane can be significantly improved by two times or more.

In addition, after adding PEG-POSS and PEBAX 3533 to the solvent, it is possible to obtain a composition for coating a hollow fiber membrane in which PEG-POSS and PEBAX 3533 are uniformly dissolved by heating at a temperature of 80° C. or higher.

Next, the composition for coating the hollow fiber membrane may further perform the step of removing by-products, and the step of removing the by-products may be performed through filtering.

In addition, since the obtained composition for coating the hollow fiber membrane is in the form of a gel at room temperature and is in a liquid state at 50° C. or higher, it can be coated on the surface of the hollow fiber membrane when in a liquid state. Preferably, the surface of the hollow fiber membrane may be coated with a coating layer comprising PEG-POSS and PEBAX 3533 through dip coating.

The (C) coating step may have a coating temperature of 50 to 70 °C. In addition, in the (C) coating step, the coating time may be 50 to 100 seconds. In addition, in the (C) coating step, the number of coatings may be 1 to 2 times.

As described in Experimental Examples to be described later, (i) the coating temperature is 50 to 70 ° C., (ii) the coating time is 50 to 100 seconds, (iii) the number of coatings is 1 to 2 times, (iv) The content of polyhedral oligomeric silsesquioxane based on the total weight of polyethylene glycol-polyhedral oligomeric silsesquioxane is 80 to 90% by weight, (v) polyethylene glycol-polyhedral oligomeric silsesquioxane And the weight ratio of the polyether polyamide block copolymer is 1: 0.9 to 1.1, (vi) the solvent is isopropanol, (vii) the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether When all the conditions of 95 to 97 wt% of the solvent are satisfied with respect to 2 to 4 wt% of a mixture of polyamide block copolymer (PEBAX) 3533, carbon dioxide selectivity to oxygen including carbon dioxide permeability during coating of the hollow fiber membrane is significantly improved became In addition, it was possible to significantly suppress the shrinkage of the hollow fiber membrane and prevent the hollow fiber membrane from being easily separated due to weakening of the adhesive strength between the hollow fiber membrane and the coating layer. In addition, even if the gas supply amount is increased by increasing the size of the module using the composite hollow fiber membrane, it was possible to suppress the rapid decrease in permeability or selectivity.

Furthermore, in the method for manufacturing a composite hollow fiber membrane according to the present invention, the performance of the hollow fiber membrane can be greatly improved by only one step of dip coating with the composition for coating the hollow fiber membrane, thereby simplifying the manufacturing process and improving productivity.

In particular, as in the experimental example of the present invention, since coating conditions (temperature, time, concentration, number of times) have a significant effect on selectivity and transmittance, in order to improve the performance of the conventional hollow fiber membrane, the coating temperature, coating time, concentration and Even the same conditions must be satisfied, and if any one of them is out of the above range, the carbon dioxide selectivity and permeability of the hollow fiber membrane cannot be remarkably improved, but rather can only cause negative effects.

The coated composite hollow fiber membrane may further include a drying step. The drying may be performed through a process of removing the residual solvent by primary drying, preferably by hot air drying for 30 seconds or more, and secondary drying at a temperature of 50° C. or more.

Hereinafter, manufacturing examples and embodiments according to the present invention will be described in detail with accompanying drawings.

Preparation Examples 1 to 3: Synthesis of PEG-POSS

PEG-POSS was synthesized so that the content of POSS was 50 wt%, 70 wt%, and 90 wt% with respect to the total weight of PEG-POSS, and was named POSS50wt, POSS70wt and POSS90wt, respectively, as Preparation Examples 1 to 3. The synthesis of PEG-POSS was carried out in three steps.

As a first step, Allyl group was introduced into the PEG monomer to synthesize Allyl-PEG. The synthesis process was synthesized by adding NaH and Allyl bromid using a tetrahydrafuran solvent to a polyethylene glycol monomer in a nitrogen atmosphere and reacting for more than 12 hours. After completion of the reaction, the obtained product was dissolved using toluene and then washed with distilled water to remove residual impurities. As a second step, Allyl-POSS in which an Allyl group was introduced into POSS was synthesized. The synthesis process was synthesized by adding triethylamine and allyl trichlorosilane to the POSS polymer using a tetrahydrafuran solvent and reacting for more than 24 hours. After completion of the reaction, the remaining solvent was removed through a filter, dissolved in benzene, and re-precipitated in acetonitrile to remove impurities. In the third step, allyl-PEG and Allyl-POSS synthesized previously using toluene solvent were added to poly(methylhydrosiloxane) and reacted for more than 72 hours to finally synthesize PEG-POSS. After completion of the reaction, impurities were removed by precipitation in methanol and washing.

Examples and Comparative Examples: Preparation of a composition for coating a hollow fiber membrane

The POSS50wt, POSS70wt and POSS90wt synthesized in Preparation Examples 1 to 3 were dried in an oven at 50° C. or higher for 24 hours to remove moisture. The dried POSS50wt, POSS70wt, and POSS90wt were mixed with PEBAX 1657, 2533, 3533 in a weight ratio of 1:1, respectively, and dissolved by heating to 80° C. or higher in isopropanol. Then, a by-product was filtered using a wire mesh to obtain a composition for coating a hollow fiber membrane. . A composition for coating a hollow fiber membrane was prepared by mixing the POSS and PEBAX 3533 mixture isopropane in the ratio shown in Table 1 below (see FIG. 1).

division POSS-PEG
(weight, g) PEBAX (weight, g) Solvent (weight, g) 1657 2533 3533 IPA IPA/BuOH BuOH EtOH EtOH/H ₂ O Example 1 POSS50wt
1.5 - - 1.5 97 - - - - Example 2 POSS70wt
1.5 - - 1.5 97 - - - - Example 3 POSS90wt
1.5 - - 1.5 97 - - - - Example 4 POSS90wt
1.5 - - 1.5 - 97 - - - Example 5 POSS90wt
1.5 - - 1.5 - - 97 - - Example 6 POSS90wt
1.5 - - 1.5 - - - 97 - Example 7 POSS90wt
0.25 - - 0.25 99.5 - - - - Example 8 POSS90wt
0.5 - - 0.5 99 - - - - Example 9 POSS90wt
2.5 - - 2.5 95 - - - - Comparative Example 1 POSS90wt
1.5 1.5 - - - - - - 97 Comparative Example 2 POSS90wt
1.5 1.5 - - - - - 97 - Comparative Example 3 POSS90wt
1.5 1.5 - - - 97 - - - Comparative Example 4 POSS90wt
1.5 1.5 - - - - 97 - - Comparative Example 5 POSS90wt
1.5 - 1.5 - 97 - - - - Comparative Example 6 POSS90wt
1.5 - 1.5 - - 97 - - - Comparative Example 7 POSS90wt
1.5 - 1.5 - - - 97 - - Comparative Example 8 POSS90wt
1.5 - 1.5 - - - - 97 -

Examples and Comparative Examples: Preparation of Composite Hollow Fiber Membrane

(1) Manufacturing of hollow fiber membranes

Using a dope solution containing 15% by weight of PAN content, 81% by weight of NMP, and 4% by weight of glycerol, a hollow fiber membrane was prepared under an air gap of 10 cm spinning condition.

(2) Hollow fiber membrane coating

The hollow fiber membrane was put into a solution in which polyethylene (PEG 200) (P0840, Sejinshii Co., Ltd.) was dissolved, and then impregnated for 24 hours. Next, Examples 3 (coating composition concentration 3 wt%), Example 7 (coating composition concentration 0.5 wt%), Example 8 (coating composition concentration 1 wt%), Example 9 on the PEG-impregnated hollow fiber membrane (Coating composition concentration 5% by weight) The prepared hollow fiber membrane coating composition was dip-coated, respectively. At this time, coating conditions such as coating temperature, time, and number of times were prepared as shown in Table 2 below, and the composite hollow fiber membranes prepared under each condition were classified into Examples 10 to 24.

Finally, the hollow fiber membrane coated with the composition for coating the hollow fiber membrane was first dried with hot air for 1 minute with a primary heating gun, and then dried in an oven at 60° C. or higher for 24 hours or more, thereby PEG-POSS and A PEBAX 3533 layer was formed.

For gas permeability measurement, each of the composite hollow fiber membranes was used by fastening each composite hollow fiber membrane module using 10 strands, wherein the module had a length of 15 cm and a width of 1/4 inch.

division Coating composition concentration coating temperature
℃ coating time
seconds(s) number of coatings Example 10 3% by weight 20 60 One Example 11 3% by weight 40 60 One Example 12 3% by weight 60 60 One Example 13 3% by weight 80 60 One Example 14 3% by weight 100 60 One Example 15 3% by weight 60 30 One Example 16 3% by weight 60 120 One Example 17 3% by weight 60 180 One Example 18 3% by weight 60 240 One Example 19 0.5% by weight 60 60 One Example 20 1% by weight 60 60 One Example 21 5% by weight 60 60 One Example 22 3% by weight 60 60 0 Example 23 3% by weight 60 60 2 Example 24 3% by weight 60 60 3

The pretreatment with PEG is performed incidentally to the step before coating the material exhibiting main performance in order to prevent defects of the hollow fiber membrane for gas separation and improve transparency, through which an intermediate layer can be formed on the surface of the hollow fiber membrane. there is.

Thereafter, by coating with a composition for coating a hollow fiber membrane exhibiting main performance, a selectivity layer (selectivity layer) may be formed on the surface of the hollow fiber membrane, and is also referred to as a 'coating layer' in a broader range. This means a coating layer that greatly affects the performance of a composite hollow fiber membrane for gas separation formed by coating a composition for coating a hollow fiber membrane that exhibits main performance. Here, it is most important to coat thinly and uniformly because the thicker the coating layer, the lower the selectivity.

Experimental Example 1: Gas permeability analysis according to PEBAX type

The purpose of this study was to compare the gas permeability according to the mixing of POSS-PEG polymer and PEBAX 3 types (2533, 3533, 1657).

The composition for coating a hollow fiber membrane prepared in Comparative Examples 1, 5 and Example 3 was applied to a Petri dish made of Teflon material to volatilize the solvent to prepare a 100 μm membrane, and gas permeability thereof was evaluated.

In order to check the gas permeability and selectivity, a time-lag device of various pressure/constant volume methods was used, and the gas permeability characteristics _{were the same for all 99% N 2} , O ₂ , CO ₂ gas at a pressure of 2000 torr. measured.

Specifically, after fastening the gas separation membrane flat membrane or gas separation membrane module prepared in the compositions for coating hollow fiber membranes of Comparative Examples 1, 5 and 3 to a gas separation membrane cell (area 14 cm ^{2 ) at room temperature (25 ℃), the cell} Gas (purity 99% N ₂ , O ₂ , CO ₂ gas) of a certain pressure (2000 torr) was injected into the upper part of the . The pressure at the bottom of the permeate held in a vacuum is constantly increased after a certain period of time, and the slope value at this time was measured to evaluate each gas permeability of the gas separation membrane, which is shown in Table 3 below.

division Gas Permeability (Barrer*) Selectivity N ₂ O ₂ CO ₂ CO ₂ /N ₂ CO ₂ /O ₂ Comparative Example 5 11 36 368 33.4 10.2 Example 3 4.8 11 182 37.9 16.5 Comparative Example 1 2.3 6.1 134 58.2 21.9 ^* Barrer=10 ^-10 cm·cm ³ (STP)/cm ² ·cmHg·s

As shown in Table 3, when comparing the performance of the single membrane of the composition for coating a hollow fiber membrane, the membrane prepared in Comparative Example 5 had the best carbon dioxide permeability, and it was confirmed that the membrane prepared in Comparative Example 1 had the best carbon dioxide/oxygen selectivity. became

Experimental Example 2: Gas permeability analysis according to solvent

A composite hollow fiber membrane was prepared in the same manner as in Example 17, except that the composition for coating the hollow fiber membrane prepared in Examples 3 to 6 and Comparative Examples 1 to 8 was used. The gas permeability of each of the prepared composite hollow fiber membranes was measured, which was performed in the same manner as in Experimental Example 1.

2 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Comparative Examples 1 to 4 of the present invention [EtOH/ H2O is Comparative Example 1, EtOH is Comparative Example 2, IPA is Comparative Example 3, and BuOH is a composite hollow fiber membrane prepared using Comparative Example 4].

3 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Comparative Examples 5 to 8 of the present invention [IPA is Comparative Example 5, IPA/BuOH is Comparative Example 6, BuOH is Comparative Example 7, and EtOH is a composite hollow fiber membrane prepared using Comparative Example 8].

4 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating hollow fiber membranes of Examples 3 to 6 of the present invention [IPA is Example 3, IPA/BuOH is Example 4, BuOH is Example 5, EtOH is a composite hollow fiber membrane prepared using Example 6]. At this time, IPA means Isopropanol, Buthanol, IPA/BuOH means Isopropanol-Butanol co-solvent, BuOH means Butanol, EtOH means Ethanol and EtOH/H ₂ O means Ethanol-H 2 O co-solvent.

2 to 4, in the case of the composite hollow fiber membrane prepared with the composition for coating the hollow fiber membrane of Comparative Examples 1 to 4, it is difficult to coat because it does not dissolve at all in solvents except Comparative Examples 1 and 2, and is less than 1% by weight. When the concentration was lowered, coating was possible, but a problem was found that both selectivity and transmittance were degraded to the extent that it was impossible to measure. The composite hollow fiber membranes prepared in Comparative Examples 1 and 2 were measured to have 4.9 selectivity and 25.5 GPU transmittance, but were not properly impregnated into the hollow fiber membrane having a hydrophilic surface during the coating process, resulting in failure to form a uniform coating layer. It is considered to be difficult to apply to processes that require mass production because it is difficult to handle, such as not drying completely.

In the case of the composite hollow fiber membranes prepared with the composition for coating the hollow fiber membranes of Comparative Examples 5 to 8, it was confirmed that, depending on the solvent, when the selectivity was high, the transmittance was significantly lowered to less than 20 GPU, and when the transmittance was high, the selectivity was significantly lowered to 1 or less.

On the other hand, in the case of the composite hollow fiber membranes prepared with the composition for coating the hollow fiber membranes of Examples 3 to 6 according to the present invention, it was confirmed that the selectivity and transmittance were improved in a well-balanced manner as compared to Comparative Examples 5 to 8. Specifically, the composite hollow fiber membrane prepared with the composition for coating a hollow fiber membrane of Example 3 showed high selectivity and high transmittance with a selectivity of 7.1 and a transmittance of 52.4, and the composite hollow fiber membrane prepared with the composition for coating a hollow fiber membrane of Example 5 It also showed 2.2 selectivity and high transmittance of 98.3 GPU.

That is, it was confirmed through Experimental Example 1 that 1657 or 2533 was the most preferable among the three PEBAX types if only the performance of the coating layer formed of the composition for coating a simple hollow fiber membrane was compared without considering the bonding relationship with the hollow fiber membrane. However, as a coating layer of the hollow fiber membrane, it was confirmed that PEBAX 3533 exhibited the most uniform coating layer and the best performance. This can be confirmed more clearly through the following experiment.

Experimental Example 3: Gas permeability analysis of composite hollow fiber membranes according to PEBAX

A composite hollow fiber membrane was prepared in the same manner as in Example 17, except that the composition for coating the hollow fiber membrane prepared in Example 3, Comparative Example 1, and Comparative Example 5 was used. The gas permeability of each of the prepared composite hollow fiber membranes was measured, which was performed in the same manner as in Experimental Example 1.

5 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared using the compositions for coating the hollow fiber membranes of Example 3, Comparative Example 1, and Comparative Example 5 of the present invention; It is a graph shown [POSS/2533 is Comparative Example 5, POSS/3533 is Example 3, and POSS/1657 is Comparative Example 1. POSS-PEG is a control, a composite hollow fiber membrane (solvent: methanol) was prepared using the POSS90wt prepared in Preparation Example 3.]

As shown in FIG. 5 , the composite hollow fiber membrane prepared only with POSS-PEG had a carbon dioxide/oxygen selectivity of 1.7 and a carbon dioxide permeability of 1056 GPUs.

The composite hollow fiber membrane prepared with the composition for coating the hollow fiber membrane of Comparative Example 1 was not uniformly blended with POSS-PEG, which is a hydrophilic polymer, due to a high polyimide group content, and thus had the lowest selectivity.

The composite hollow fiber membrane prepared with the composition for coating the hollow fiber membrane of Comparative Example 5 had relatively higher selectivity than Comparative Example 1, but it was confirmed that the carbon dioxide permeability was significantly lower than 100 GPU.

On the other hand, the composite hollow fiber membrane prepared with the composition for coating the hollow fiber membrane of Example 3 confirmed that the carbon dioxide/oxygen selectivity was 5.8 and the carbon dioxide permeability was 146.9 GPU when the effective area was 18.84 ㎠, and at the same time, it was uniform with POSS-PEG Since mixing and coating are possible, it was confirmed that it is most preferable for coating the hollow fiber membrane.

Experimental Example 4: Gas permeability analysis according to the PEG pretreatment process

In the case of the hollow fiber membrane, compared to the gas separation membrane in the form of a flat film, the performance is significantly lower. Therefore, in order to compensate for this, it was attempted to perform a pretreatment of coating PEG on the surface of the hollow fiber membrane through PEG impregnation. The purpose of this study was to determine how the pretreatment process affects the performance of the hollow fiber membrane.

A composite hollow fiber membrane was prepared in the same manner as in Example 12, except that the composition for coating the hollow fiber membrane prepared in Example 3 and Comparative Examples 1 and 5 was used. These were sequentially named 3533*, 1657*, and 2533*.

For comparison, a composite hollow fiber membrane was prepared in the same manner as in Example 12, except that the hollow fiber membrane coating compositions prepared in Examples 3 and 1 and 5 were used, but were directly coated on the hollow fiber membrane without PEG impregnation process. did. These were sequentially named 3533, 1657, and 2533.

However, in the case of the composition for coating a hollow fiber membrane prepared in Comparative Example 1, it was difficult to coat because it did not dissolve well, so polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide A mixture of 0.8% by weight of a mixture of block copolymer (PEBAX) 1657 and 99.2% by weight of ethanol (EtOH) was used instead of Comparative Example 1. The results are shown in FIG. 6 .

6 shows the gas permeability (nitrogen, It is a graph showing the selectivity of carbon dioxide to oxygen and carbon dioxide) and oxygen.

According to FIG. 6, unlike the composite hollow fiber membranes of 3533, 1657, and 2533, it was confirmed that the composite hollow fiber membranes of 3533*, 1657*, and 2533* had improved transparency. In addition, it was confirmed that the transmittance of the composite hollow fiber membranes of 3533*, 1657*, and 2533* was improved more than twice as compared to the composite hollow fiber membranes (3533, 1657, 2533) not pretreated with the PEG solution. In particular, in the case of 3533, it can be seen that the carbon dioxide transmittance greatly increased from 52 GPU to 113 GPU, and at the same time, the carbon dioxide selectivity to oxygen also increased significantly from 7.0 to 7.7.

However, in the case of 1657 and 2533, the transmittance increased, but the selectivity decreased.

Experimental Example 5: Gas permeability analysis of composite hollow fiber membranes according to coating conditions

The gas permeability of the composite hollow fiber membranes prepared in Examples 10 to 24 was analyzed. This was performed in the same manner as in Experimental Example 1.

7 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 10 to 14 of the present invention [20 ° C is Example 10, 40 ° C is Example 11, 60°C is Example 12, 80°C is Example 13, 100°C is Example 14].

Referring to FIG. 7 , when coating is performed at less than 30° C. (composite hollow fiber membrane of Example 10), gelation of the composition for coating the hollow fiber membrane occurs. There was a problem with sticking. Accordingly, it was confirmed that the composite hollow fiber membrane of Example 10 did not form a coating layer at all or caused damage to the surface of the hollow fiber membrane.

When the coating was performed at 40° C. (Example 11), very low carbon dioxide permeability was exhibited. In addition, when the coating is carried out at 60 ° C. or higher (Examples 12, 13, and 14), the agglomeration phenomenon between the hollow fiber membranes is eliminated, and the carbon dioxide selectivity to oxygen (CO ₂ /O ₂ ) is maintained at 5.1 to 6.8. confirmed that.

However, when the coating was performed at 80° C. or higher (Examples 13 and 14), the carbon dioxide/oxygen selectivity was significantly reduced to less than half while the permeability to carbon dioxide was increased. In addition to performance, it was confirmed that the mechanical properties of the overall composite hollow fiber membrane were greatly reduced as the adhesive strength with the hollow fiber membrane was lowered due to prolonged exposure to a high temperature environment.

Therefore, through this experiment, it was confirmed that the coating temperature is preferably 50 to 70 ℃, more preferably 55 to 65 ℃, most preferably 60 ℃.

8 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 15 to 18 of the present invention [30 is Examples 15 and 60 are Examples 12 and 120 are Examples 16, 180 is Example 17, 240 is Example 18].

Referring to FIG. 8 , it was confirmed that the composite hollow fiber membrane of Example 15 showed high permeability to all gases, while the selectivity was remarkably low. That is, it can be seen that the composition for coating a hollow fiber membrane according to the present invention requires at least 30 seconds or more to be coated on the surface of the hollow fiber membrane.

The composite hollow fiber membrane of Example 12 was confirmed to exhibit the highest carbon dioxide permeability (290 GPU) and carbon dioxide/oxygen (CO ₂ /O ₂ ) selectivity of 5.1.

However, like the composite hollow fiber membrane of Example 17, when the coating time exceeds 2 minutes, it was confirmed that the transmittance was rapidly decreased by 2.5 to 3 times or more. As in the composite hollow fiber membrane of Example 18, when the coating time exceeds 4 minutes, it was confirmed that almost no permeation of carbon dioxide is achieved.

Therefore, through this experiment, it was confirmed that the coating time is preferably 50 to 100 seconds, more preferably 55 to 65 seconds, and most preferably 60 seconds.

9 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 19 to 21 of the present invention [0.5 is Examples 19, 1 is Examples 20 and 3 are Examples 12 and 5 are Example 21]. At this time, the hollow fiber membrane was evaluated for gas permeation characteristics using a module having an effective area of 37.68 cm2.

Referring to FIG. 9 , the composite hollow fiber membranes of Examples 19 and 20 exhibited relatively high carbon dioxide permeability (601 GPU), but carbon dioxide selectivity to oxygen (CO ₂ /O ₂ ) was relatively low at 2.7 to 3.8. It was confirmed that it was a number.

In the case of the composite hollow fiber membrane of Example 12, the transmittance was slightly decreased, but still maintained a level of 500 GPU or more, and the carbon dioxide selectivity to oxygen (CO ₂ /O ₂ ) was improved more than twice to 5.8 to 6.4, the most It was confirmed that the conditions were favorable. However, like the composite hollow fiber membrane of Example 21, when a high-concentration hollow fiber membrane coating composition was used, the transmittance was rapidly decreased by more than two times.

Therefore, through this experiment, as in Example 12, 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 and solvent 95 to 97% by weight, and most preferably 3% by weight of the mixture and 97% by weight of the solvent.

10 is a graph showing the gas permeability (nitrogen, oxygen and carbon dioxide) and the selectivity of carbon dioxide to oxygen of the composite hollow fiber membranes prepared from Examples 12 and 22 to 24 of the present invention [0 is Examples 22, 1 is Examples 12 and 2 are Examples 23 and 3 are Example 24].

Referring to FIG. 10 , the composite hollow fiber membrane of Example 22, which was not coated with the hollow fiber membrane coating composition, showed transmittance of 34,000 GPUs to carbon dioxide. However, it was confirmed that the composite hollow fiber membrane of Example 22 had transmittance of not only carbon dioxide but also nitrogen and oxygen of 30000 GPU or more.

Compared with the composite hollow fiber membrane of Example 22, the carbon dioxide selectivity to oxygen (CO ₂ /O ₂ ) at the time of one coating (Example 12) is 5 times, the carbon dioxide selectivity to nitrogen (CO ₂ /N ₂ ) was increased by 12 times.

In comparison with the composite hollow fiber membrane of Example 22, at the time of coating twice (Example 23), the carbon dioxide selectivity to oxygen (CO ₂ /O ₂ ) was 8 times, and the carbon dioxide selectivity to nitrogen (CO ₂ /N _{2 )} ) increased by 15 times. However, when the number of coatings was 3 or more (Example 24), the transmittance was rapidly decreased to 1 GPU or less. That is, it can be seen that the number of coatings is preferably performed 1-2 times.

The number of coatings confirmed in this experiment has a good effect on the selectivity, but also has a significant effect on the transmittance. If any one of these is out of the above range, the carbon dioxide selectivity and permeability of the hollow fiber membrane cannot be significantly improved, and as described above, it may rather cause only a negative effect.

Therefore, according to the present invention, a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (polyethyleneglycol-POSS, PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 is prepared and , can be used as a carbon dioxide separation membrane with excellent permeability and selectivity to carbon dioxide.

Experimental Example 6: Analysis of scale-up composite hollow fiber membrane module

In the case of the composite hollow fiber membrane of the present invention, a scale-up composite hollow fiber membrane module using the composite hollow fiber membranes of Examples 12 and 23, which differ only in the number of coatings, respectively, in order to confirm that it can be used as a large-scale module rather than a laboratory scale. was prepared, and the gas permeability thereof was evaluated.

Each of the composite hollow fiber membrane modules was fastened using 120 composite hollow fiber membranes of Example 12 or Example 23. 1C is a photograph of a composite hollow fiber membrane module in which the existing laboratory scale composite hollow fiber membrane module (Example 12) is scaled up. The scale-up composite hollow fiber membrane module (Example 12) has a length of 15 cm, a width of 3 cm, and an effective membrane area of 452 cm ² .

Gas (purity 99% N ₂ , O ₂ , CO ₂ gas) of a certain pressure (4 bar) is injected into the upper part of the module using a pressure regulator to prevent gas permeation due to the pressure difference between the upper part and the lower part of the module. induced.

At this time, the flow rate of the gas passing through the module was measured using a bubble flow meter, and the gas permeability of each gas separation membrane was evaluated in consideration of the stabilization time (> 1 hour), which is shown in FIG. 11 .

11 is a graph showing the results of analyzing the gas permeability and gas selectivity for a single gas of the composite hollow fiber membrane module of Example 12 and the composite hollow fiber membrane module of Example 23;

11 , the composite hollow fiber membrane module of Example 12 exhibited a relatively high transmittance (484 GPU) to _{carbon dioxide (CO 2 ).} However, in terms of selectivity, selectivity to CO ₂ /O ₂ was 5, and selectivity to CO ₂ /N ₂ was confirmed to be 8.

In contrast, the composite hollow fiber membrane module of Example 23 exhibited a relatively low permeability (254 GPU) to _{carbon dioxide (CO 2 ), but the selectivity to CO 2} /O ₂ was 15, and to CO ₂ /N ₂ It was confirmed that the selectivity of 25 was remarkably high.

That is, when the composition for coating a hollow fiber membrane according to the present invention is coated one or more times, the selectivity and transmittance of the hollow fiber membrane can be remarkably increased, and most preferably, the mechanical properties of the hollow fiber membrane are improved during the second coating, while 1 It can improve carbon dioxide selectivity and permeability more than 3 times compared to ash coating.

PAN hollow fibers not treated with the composition for coating a hollow fiber membrane according to the present invention (using a dope solution containing PAN content 15% by weight, NMP 81% by weight, and glycerol 4% by weight, air gap 10 cm hollow fiber membrane support) was prepared, the module was fastened with the 120 hollow fibers, and gas permeability and selectivity were analyzed in the same manner as in the above experiment, and the results are shown in Table 4 below.

division Gas Permeance (GPU) N2 O2 CO2 PAN hollow fiber not treated with composition for hollow fiber membrane coating 38,192 41,420 34,286

As shown in Table 4, it can be seen that there is no significant difference in gas selectivity and permeability in the case of the PAN hollow fiber that is not treated with the composition for coating the hollow fiber membrane.

Experimental Example 7: Performance analysis of mixed gas of scale-up composite hollow fiber membrane module

In the case of the composite hollow fiber membrane of the present invention, a scale-up composite hollow fiber membrane module was prepared using the composite hollow fiber membrane of Example 23 in order to confirm whether it is applicable to an actual mixed gas when used as a large-scale module rather than a laboratory scale and the gas permeability thereof was evaluated.

Each of the composite hollow fiber membrane modules was fastened using 120 composite hollow fiber membranes of Example 23. _{By injecting a mixed gas (CO 2} 14%, O ₂ 6%, N ₂ balance) of a constant pressure (4 bar) to the upper part of the module using a pressure regulator, the gas caused by the pressure difference between the upper part and the lower part of the module Permeation was induced.

The flow rate of the mixed gas passing through the module was measured using a bubble flow meter. Before and after passing through the module, the concentration of the mixed gas was measured using a gas chromatograph, and the permeability to the mixed gas was evaluated in consideration of the stabilization time (> 1 hour), which is shown in FIG. 12 below.

Stage cut is a factor representing the balance between recovery and purity of mixed components, and as the recovery rate increases, the purity tends to decrease. That is, the stage cut is an important factor determining the separation performance when separating the mixed gas, and can be expressed as a ratio of the flow rate of the mixed gas to be supplied and the flow rate of the mixed gas to be supplied. In general, as the stage cut increases, the ratio of the supply pressure and the permeation pressure increases, so that the purity increases and the recovery rate decreases. Also in this experiment, as the stage cut increased from 0.02 to 0.12, the concentration (ie, purity) of _{the transmitted CO 2 gas increased.}

12 is a graph showing the result of analyzing the gas permeability to the mixed gas of the composite hollow fiber membrane module of Example 23.

As shown in FIG. 12 , in the composite hollow fiber membrane module of Example 23, as the stage cut increased, the permeation concentrations of _{CO 2} and O _{2 increased.} Each concentration in the permeated mixed gas was found to be 19% _{CO 2} , 10% _{O 2} , and 71% _{N 2 .} As a result of measuring the permeated mixed gas, it was confirmed that the permeability of carbon dioxide and oxygen gas was substantially significantly increased compared to the mixed gas composition before passing through the module (CO ₂ 5% increase, O ₂ 4% increase).

PAN hollow fibers not treated with the composition for coating a hollow fiber membrane according to the present invention (using a dope solution containing PAN content 15% by weight, NMP 81% by weight, and glycerol 4% by weight, air gap 10 cm Hollow fiber membrane support), it was confirmed that there was no change in the composition of the mixed gas before and after the permeation.

Claims (16)

A composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533. 3. The method of claim 2,
The polyhedral oligomeric silsesquioxane (POSS) is 85 to 95 wt% based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) for coating a hollow fiber membrane composition. According to claim 1,
The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 is 1: 0.5 to 1.5. According to claim 1,
The composition for coating the hollow fiber membrane further comprises a solvent,
The solvent is a composition for coating a hollow fiber membrane, characterized in that isopropanol. 5. The method of claim 4,
95 to 97 wt% of the solvent based on 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 A composition for coating a hollow fiber membrane. hollow fiber membrane; and
A composite hollow fiber membrane comprising a; polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and a coating layer comprising polyether polyamide block copolymer (PEBAX) 3533 formed on the hollow fiber membrane. 7. The method of claim 6,
A composite hollow fiber membrane, characterized in that it further comprises a polyethylene glycol (PEG) layer between the hollow fiber membrane and the coating layer. A carbon dioxide separation membrane comprising the composite hollow fiber membrane according to claim 6 . (A) impregnating the hollow fiber membrane in a polyethylene glycol (PEG) solution;
(B) pretreatment by drying the hollow fiber membrane of step (A) at a temperature of 10 to 50 °C; and
(C) Coating a composition for coating a hollow fiber membrane comprising polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 on one surface of the pretreated used sand membrane A method of manufacturing a composite hollow fiber membrane comprising; 10. The method of claim 9,
The polyhedral oligomeric silsesquioxane (POSS) is 85 to 95 wt% based on the total weight of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS). manufacturing method. 10. The method of claim 9,
The weight ratio of the polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 is 1: 0.5 to 1.5. 10. The method of claim 9,
The composition for coating the hollow fiber membrane further comprises a solvent,
The method for producing a composite hollow fiber membrane, characterized in that the solvent is isopropanol. 13. The method of claim 12,
95 to 97 wt% of the solvent based on 2 to 4 wt% of a mixture of polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) and polyether polyamide block copolymer (PEBAX) 3533 A method for manufacturing a composite hollow fiber membrane. 10. The method of claim 9,
The step (C) is a method for producing a composite hollow fiber membrane, characterized in that the coating temperature is 50 to 70 ℃. 10. The method of claim 9,
The (C) step is a method for producing a composite hollow fiber membrane, characterized in that the coating time is 50 to 100 seconds. 10. The method of claim 9,
The (C) step is a method of manufacturing a composite hollow fiber membrane, characterized in that the number of coatings is 1 to 2 times.

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