KR20170034018A - Hollow Fiber Membrane for Separating Oxygen and Method for Manufacturing thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane for oxygen separation, and more particularly to a hollow fiber membrane for oxygen separation in which a coating layer containing a transition metal compound is formed. The hollow fiber membrane for oxygen separation according to the present invention exhibits high efficiency in separation of oxygen gas in combustion exhaust gas by coating the composition containing the transition metal compound on the porous tubular polymer membrane, and thus has high oxygen gas selectivity and permeability even at low pressure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane for oxygen separation,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane for oxygen separation, and more particularly to a hollow fiber membrane for oxygen separation in which a coating layer containing a transition metal compound is formed.

Recently, interest in the environment and energy has been increasing, and researches on oxygen membranes have been actively carried out. Oxygen separation membrane extracts only pure oxygen from the air and is widely used in the field of ammonia synthesis and other synthetic chemical industries, metallurgy, metal welding, and cutting. It is also used in the post-combustion capture process, which is a technique for capturing the carbon dioxide contained in the post-combustion flue gas in relation to the carbon dioxide capture technique. The most important design factor in the separation process using the wet sorbent which is most widely used during the post-combustion capture process is the efficiency and rate of carbon dioxide removal of the sorbent. In this case, when oxygen is present in the flue gas, The carbon dioxide absorbing ability is lowered due to the oxidative degradation.

Examples of the oxygen separation method include a cryogenic method, a pressure swing adsorption method, and a membrane separation method. Although PSA and PSA are commercialized in this process, there is a disadvantage in that a large amount of oxygen separation process requires a large amount of investment and energy due to the characteristics of the equipment. On the other hand, the oxygen separation process using membranes, which has been actively researched recently, is expected to replace the existing processes with high efficiency and low process cost as compared with the existing gas separation technology.

The oxygen separation method using a separation membrane is a separation method using a ceramic separation membrane or a polymer separation membrane. Oxygen separation using a ceramic membrane separates oxygen and electrons from oxygen in various components of the air. The separated oxygen ions and electrons are respectively transmitted through the oxygen separation membrane, and the transferred oxygen ions and electrons are recombined to allow oxygen molecules to escape to the outside of the oxygen separation membrane, thereby separating pure oxygen. However, the ceramic separator is driven at a high temperature, requires a catalyst containing a noble metal, and is expensive to manufacture. The oxygen separation method using the polymer membrane uses the principle of molecular sieve to separate oxygen according to the size of the gas molecules. The oxygen separation method using the conventional polymer membrane has a problem in that the selectivity and the permeability are inversely proportional to each other. Therefore, compounds that fix oxygen molecules are used to improve oxygen selectivity. As such a substance capable of selectively binding oxygen, for example, a cobalt porphyrin derivative for cobalt-doping at the center of a porphyrin molecule is known. Cobalt porphyrin derivatives have the same shape as hemoglobin and can selectively and reversibly bind oxygen molecules through a single permeation of air. However, since the cobalt porphyrin derivative itself is formed of solid particles, it can not maintain its own film shape. Therefore, it is necessary to coat the polymer membrane with a selective oxygen fixing and releasing function of the cobalt porphyrin derivative, A method is needed.

Japanese Patent Application Laid-Open No. 2013-03372 discloses a plate-type electrode such as ceramic, which is an inorganic porous substrate coated with a transition metal complex, with respect to a selective oxygen permeable membrane. However, this is a flat plate type separator for use in a battery, and a separation cost of high temperature and high temperature is required by using a ceramic.

Korean Patent No. 0646312 discloses a hollow-fiber oxygen separator and a method for producing the hollow-oxygen separator, and discloses a small separation membrane system in which a hollow fiber membrane manufactured using a polymer material having permselectivity is operated by a vacuum pump. However, this requires the supply of a high pressure gas, and the selectivity and the transmission efficiency are low in a low pressure gas supply.

Therefore, it is necessary to develop an oxygen separation membrane having high selectivity and permeability and exhibiting high efficiency even at low pressure.

Japanese Laid-Open Patent Publication No. 2013-03372 Korean Patent No. 0646312

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a hollow fiber membrane for oxygen separation in which a coating layer containing a transition metal compound is formed.

The present inventors have succeeded in separating the oxygen in the flue gas using a hollow fiber membrane for oxygen separation in the post-combustion collecting process of collecting carbon dioxide contained in the flue gas after combustion and injecting the oxygen-depleted flue gas into the absorption tower, Absorbing ability can be maximized, thus completing the present invention.

In one aspect, the present invention provides a porous tubular polymer membrane; And a porous coating layer formed outside the tubular polymer membrane, wherein the coating layer comprises a transition metal-porphyrin compound and a polymer compound.

The polymer film and the polymer compound may be made of the same or different polymer materials, and the polymer material may be a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester Wherein the polymer is at least one selected from the group consisting of a polymer, an olefin polymer, a polybenzimidazole polymer, and polyvinylidene fluoride.

The transition metal-porphyrin compound may be at least one selected from the group consisting of Co, Cu, Fe, Ni, Mn, Ru and Rh, ), Magnesium (Mg), lead (Pb), palladium (Pd), zinc (Zn), titanium (Ti), vanadium (V), chromium (Cr) One or more transition metals selected; A porphyrin or a tetraphenylporphyrin selected from the group consisting of porphyrin ligand and imidazole, pyridine, benzoimidazole, benzopyridine and benzylimidazole. ≪ / RTI > wherein the at least one axial ligand is at least one of the axial ligands.

The present invention also provides a hollow fiber membrane for oxygen separation, wherein the coating layer is 0.5 nm to 400 nm thick.

The present invention also provides a method of preparing a porous tubular polymer membrane, comprising the steps of: preparing a spinning solution containing a polymer; Preparing a coating solution coated on the porous tubular polymer membrane; And coating the coating solution on the porous tubular polymeric membrane, wherein the step of preparing the coating solution comprises: preparing a transition metal-porphyrin compound; And a step of mixing the transition metal-porphyrin compound, the polymer compound, and the organic solvent to prepare a hollow fiber membrane for oxygen separation.

The transition metal-porphyrin compound may be at least one selected from the group consisting of Co, Cu, Fe, Ni, Mn, Ru and Rh, ), Magnesium (Mg), lead (Pb), palladium (Pd), zinc (Zn), titanium (Ti), vanadium (V), chromium (Cr) One or more transition metals selected; Wherein the at least one compound is selected from the group consisting of porphyrin or tetraphenylporphyrin and imidazole, pyridine, benzoimidazole, benzopyridine and benzylimidazole. A method for producing a hollow fiber membrane for oxygen separation, comprising a ligand.

In the present invention, it is preferable that the spinning solution contains 10 to 30% by weight of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, Polymer or polyvinylidene fluoride, a mixture of 70 to 80% by weight of N-methylpyrrolidone, and 2 to 10% by weight of lithium chloride, A method for producing a membrane is provided.

The coating solution may further comprise a mixture of a transition metal-porphyrin compound and a polymer compound in a weight ratio of 100: 1 to 100: 50, and the polymer compound may be a polysulfone polymer, a polyamide polymer, A method for producing a hollow fiber membrane for oxygen separation, wherein the hollow fiber membrane is one or more selected from the group consisting of a mid polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer, or polyvinylidene fluoride .

The coating step may be performed by dipping the porous tubular polymer membrane in a coating solution at 25 DEG C to 100 DEG C for 1 to 60 seconds and then drying at 50 DEG C to 100 DEG C to wind the coating film on a winding machine. A method for producing a membrane is provided.

The hollow fiber membrane for oxygen separation according to the present invention exhibits high efficiency in separation of oxygen gas in the combustion exhaust gas due to high selectivity and permeability of oxygen gas even at low pressure by coating a composition containing the transition metal compound on the porous tubular polymer membrane.

1 is a schematic view illustrating a method of manufacturing a porous tubular polymer membrane according to an embodiment of the present invention.
FIG. 2 illustrates a method of forming a coating layer on the outer side of a porous tubular polymer membrane according to an embodiment of the present invention.
3 is an ATR-IR spectrum of a porous tubular polymer membrane having a porous tubular polymer membrane and a coating layer according to an embodiment of the present invention.
4 is an SEM image showing a cross section of a hollow fiber membrane for oxygen separation according to one embodiment of the present invention.
FIG. 5 illustrates a gas permeability measurement system according to an embodiment of the present invention.
FIG. 6 is a graph showing gas permeabilities of oxygen and nitrogen by a hollow fiber membrane for oxygen separation according to an embodiment of the present invention.
7 is a graph showing gas selectivity by the hollow fiber membrane for oxygen separation according to one embodiment of the present invention.
8 is a graph showing gas selectivity and permeability of oxygen, nitrogen, and carbon dioxide by a hollow fiber membrane for oxygen separation according to an embodiment of the present invention.

Prior to the detailed description of the present invention, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

In one aspect, the present invention provides a porous tubular polymer membrane; And a porous coating layer formed outside the tubular polymer membrane, wherein the coating layer comprises a transition metal-porphyrin compound and a polymer compound. The separation membrane can be defined as an interface (material) having a function of selectively restricting the movement of a substance between two phases. Gas separation using membranes proceeds by selective gas permeation principle for membranes. That is, when the gas mixture contacts the surface of the membrane, the gas component dissolves and diffuses into the membrane, where the solubility and permeability of each gas component is different for the membrane material. The propulsive force for gas separation is the partial pressure difference for the particular gas component applied across the membrane. In particular, the membrane separation process using a separation membrane has been widely used in various fields because it has no phase change and energy consumption is low. The present invention provides a hollow fiber membrane for oxygen separation which separates oxygen from the post-combustion exhaust gas supplied to the carbon dioxide capture.

The hollow fiber membrane for oxygen separation of the present invention is a two-layer structure in which a porous tubular polymer membrane is used as a support and a coating layer is formed thereon. In one embodiment, the material of the tubular hollow fiber membrane is selected from the group consisting of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer, A polyether sulfone, a polyether sulfone, a polyether sulfone, and a fluoride, and preferably a polysulfone, a polyether sulfone, a sulfonated polysulfone, a polyvinylidene fluoride, a polyacrylonitrile, a polyimide, Polybenzimidazole, polyamide, and the like. The tubular polymer membrane has a diameter of 100 mu m to 1,500 mu m, preferably 400 mu m to 1,000 mu m. Also, the surface of the membrane is porous allowing gas to permeate, and the pore size is from 10 nm to 400 nm.

The coating layer coated on the outside of the tubular polymer membrane of the present invention includes a transition metal-porphyrin compound and a polymer compound. When an oxygen-containing mixed gas, for example, a combustion gas, is injected into a hollow fiber membrane for oxygen separation, it is diffused into a separation membrane to be in contact with a transition metal porphyrin compound coated on the outer side of the tubular polymer membrane, and oxygen is converted into a transition metal- Adsorbed and desorbed on the compound to separate oxygen from the mixed gas. In one embodiment, the transition metal-porphyrin compound may be efficiently coated on the tubular polymer membrane as a support by preparing a coating solution in a liquid state by mixing with a polymer compound and a solvent. The coating solution is preferably low in viscosity and thinly formed on the support so as not to deteriorate the performance of the tubular polymer membrane. In one embodiment, the transition metal is selected from the group consisting of Co, Cu, Fe, Ni, Mn, Ru and Rh, Pt, At least one element selected from the group consisting of Mg, Pb, Pd, Zn, Ti, V, Cr, Ag, Transition metal, preferably cobalt (Co). The porphyrin of the present invention is a ligand to which a metal can be coordinated, and is collectively referred to as a porphyrin or porphyrin derivative, and is preferably tetraphenylporphyrin. The transition metal-porphyrin compound comprises, in addition to the porphyrin ligand, an axial ligand of the porphyrin ligand. The axial ligand can induce oxygen adsorption active sites of the transition metal-porphyrin compound to enhance oxygen selectivity and promote oxygen transport. In one embodiment, the axial ligand is at least one selected from the group consisting of imidazole, pyridine, benzoimidazole, benzopyridine, and benzylimidazole, Preferably a benzimidazole.

The coating layer of the present invention includes a polymer compound. The polymer compound is intended to facilitate the formation of a coating layer containing a transition metal-porphyrin compound on the outside of the porous tubular polymer membrane. It is preferable that the adhesion between the coating layer and the tubular polymer membrane is improved during formation of the coating layer and the transition metal- And the coating layer is solidified. In one embodiment, the polymer compound is the same as or different from the material of the porous tubular polymer membrane, and the polymer is selected from the group consisting of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, Based polymer, a polybenzimidazole polymer, or polyvinylidene fluoride, and is preferably at least one selected from the group consisting of polysulfone, polyethersulfone, sulfonated polysulfone, polyvinylidene fluoride, polyacrylonitrile , Polyimide, polyetherimide, polyester, polybenzimidazole, and polyamide. The coating layer comprising the transition metal-porphyrin compound and the polymer compound is coated on the outside of the porous tubular polymer membrane with a thickness of 0.5 nm to 400 nm, preferably 50 nm to 400 nm. The coating layer having a thickness of 0.5 nm or less has poor oxygen selectivity, and the coating layer having a thickness of 400 nm or more has a low transmittance. The hollow fiber membrane for oxygen separation of the present invention can be used to separate the oxygen in the combustion exhaust gas before feeding it to the carbon dioxide capture device in supplying oxygen-containing combustion exhaust to the carbon dioxide capture device. Conventional oxygen separation or deoxygenation apparatuses require oxygen at a high pressure or a high temperature driving environment in the case of a ceramic separation membrane. However, according to the present invention, a porous tubular polymer membrane can be coated with a transition metal-porphyrin compound, which is a reversible oxygen adsorption compound, to perform oxygen separation at a relatively mild condition of low pressure and low temperature with high efficiency.

According to another aspect of the present invention, there is provided a method for producing a hollow fiber membrane for oxygen separation, comprising the steps of: preparing a spinning solution containing a polymer; Preparing a porous tubular polymer membrane through the nozzle with the spinning solution; Preparing a coating solution coated on the porous tubular polymer membrane; And coating the coating solution on the porous tubular polymeric membrane, wherein the step of preparing the coating solution comprises: preparing a transition metal-porphyrin compound; And a step of mixing the transition metal-porphyrin compound, a polymer compound and an organic solvent.

The porous tubular polymer membrane can be produced by, for example, a dry-wet phase inversion method. A spinning solution is prepared, which is made into a tubular polymer membrane through a nozzle. In one embodiment, the spinning solution comprises 10 to 30% by weight of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer Or polyvinylidene fluoride, and a mixture of 70 to 80% by weight of N-methylpyrrolidone and 2 to 10% by weight of lithium chloride. 1 is a schematic view illustrating a method of manufacturing a porous tubular polymer membrane according to an embodiment of the present invention. The spinning solution (a) and the internal coagulating agent (b) are supplied to the gear pump (c) and the HPLC pump (d) under a nitrogen atmosphere, and the water bath (e) and the cooler (k) f. The polymer film emitted from the spinning device f is wound on the take-up device j after the tension test i through the first coagulation bath g and the second coagulation bath h.

The coating layer coated on the outer side of the porous tubular polymer membrane may be coated with a coating solution by preparing a coating solution by mixing a transition metal-porphyrin compound, a polymer compound, and a solvent. In one embodiment, the coating solution comprises a mixture of a transition metal-porphyrin compound and a polymer compound in a weight ratio of 100: 1 to 100: 50, the polymer compound being selected from the group consisting of a polysulfone polymer, a polyamide polymer, Based polymer, a polyimethacrylate-based polymer, a polyester-based polymer, an olefin-based polymer, a polybenzimidazole polymer, or a polyvinylidene fluoride. The transition metal-porphyrin compound and the polymer compound are dissolved in an organic solvent to prepare a coating solution. As the organic solvent, for example, toluene, chloroform, dimethylformamide, acetone, benzene, ethanol and the like can be used. The coating step is a step of injecting a coating solution into a coating apparatus and coating a tubular polymer membrane. 2, the coating apparatus includes a bobbin 100, a coating unit 110, and a winding unit 140. The tubular polymer film wound around the bobbin 100 is coated with a coating unit 110, The coating layer is formed on the outer surface of the film. The coated tubular polymer membrane 130 is wound in the winding unit 140 at the drying unit 120. In one embodiment, the coating is performed by immersing the porous tubular polymer membrane in a spinning solution in a coating solution at 25 ° C to 100 ° C for 1 to 60 seconds, drying at 50 ° C to 100 ° C, and winding on a spinning machine.

Hereinafter, embodiments are provided to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited to the following examples.

Example  1 Preparation of Porous Tubular Polymer Membrane

(PES, Ultrason E6020P, BASF, Germany), which exhibits thermal stability and high chain strength to produce a porous tubular polymeric membrane that serves as a support for oxygen-separated hollow fiber membranes. 18.0 wt% of PES solution was dried at 80 ° C for 3 days, and 5 wt% of N-methylpyrrolidone (NMP, Merck) and lithium chloride (LiCl, Sigma Aldrich, USA) The composition ratios were mixed as shown in Table 1.

[Table 1]

Distilled water was used as an internal coagulating agent in the double tube spinning nozzle having the inner facing diameter of 0.12 / 0.6 mm and spinning while maintaining the air gap at 0-20 cm to prepare a porous tubular polymer membrane. After spinning, the solvent with which the fibers remained was washed for 6 days in flowing water at a flow rate of 313 K of 50 cm ³ / min. The washed porous tubular polymer membrane was post-treated with methanol for 2 hours and dried for 6 days.

After refluxing 30.3 mL of benzaldehyde (about 0.67 M), 5 minutes later, add to the reaction solution (in 50 mL of propionic acid), add 21 mL of fresh distillation pyrrole (141 DEG C, boiling point 400 mL) For hours. After cooling, the reaction mixture was filtered through a Buchner funnel. The dark purple filter residue filtrate was colorless, washed with deionized water to remove residual propionic acid and washed with methanol until the beginning. Finally, the TPP particles were vacuum dried for 8 hours.

Example  2-1 Of the tetraphenylporphyrin (TPP)  Produce

400 ml of propionic acid at 141 ° C added with 30.3 ml of benzaldehyde (about 0.67 M) was refluxed into the reaction solution, and after 5 minutes, 21 ml of distilled pyrrole (in 50 ml of propionic acid) was added to the reaction solution and refluxed for 1 hour . The reaction solution was cooled and the product was filtered. The filtered purple birds were washed with methanol until clear and, when colorless, washed with distilled water to remove residual propionic acid. The resulting TPP particles were vacuum dried for 8 hours.

Example  2-2 Cobalt Coordination Of tetraphenylporphyrin (CoTPP)  Produce

The metallization reaction was carried out using TPP according to Example 2-1. TPP (3.5 g) and DMF (150 ml) were charged into a 250 ml round bottom flask and heated with stirring in a heating mantle at 140 < 0 > C. Anhydrous cobalt dichloride (3.0 g) was added to the heated reaction solution and refluxed for 6 hours. After the reaction was completed, the solvent was removed by using a vacuum rotary evaporator and concentrated. To the concentrated product, 150 mL of anhydrous ethanol was added and crystallization was carried out in a refrigerated state at 1 to 15 DEG C for one day to obtain CoTPP of purple crystals. The resulting CoTPP was filtered, washed with a small amount of distilled water and anhydrous ethanol, and vacuum-dried for 8 hours.

Example  3 Preparation of Hollow Fiber Membrane for Oxygen Separation

To prepare a hollow fiber membrane for oxygen separation, a coating solution was prepared to coat CoTPP prepared according to Examples 2-1 and 2-2 on the porous tubular polymer membrane prepared in Example 1 above. The coating solution was prepared by mixing polybutyl methacrylate (PBMA) and CoTPP in toluene as shown in Table 2. As shown in FIG. 2, a coating was performed outside the porous tubular polymer membrane with a continuous coating system. When the porous tubular polymer membrane wrapped on the bobbin was put into a coating solution at room temperature and a coating layer was formed on the outer side, it was sent to a vertical drying unit of 3.2 m to cure and dry the coating layer at 80 ° C. The dried membrane for oxygen separation was wound on a winder and the thickness of the coating layer was determined by controlling the speed of the winder.

[Table 2]

Example  Analysis of Hollow Fiber Membrane for Oxygen Separation

Example 1 to 3 ATR-FTIR spectrum (Bruker) of PES tubular polymer film at 600 to 4,000cm ^-1 range to analyze the surface of hollow fiber membranes for oxygen separation, PBMA-PES and CoTPP-PBMA-PES in accordance with the Were measured. The results are shown in Fig. The ATR-FTIR spectra of the PES tubular polymer membranes were observed at 1105, 1149, 1240, 1290, 1321 and 1,484 cm ^-1 , indicating CO stretching, symmetrical stretching of O = S = O, aromatic ether and CN stretching, O = S = O Asymmetric stretching, aromatic C = C corresponds to stretching. The 1487 and 1578 cm <" ¹ > peaks are specific peaks of PES. In the ATR-FTIR spectrum of PBMA-PES, a broad band-type peak corresponding to -OH in the region of 2800 to 3000 cm ^-1 was measured. The ATR-FTIR spectra of CoTPP-PBMA-PES overlapped most of the characteristic absorption bands of PBMA, but the characteristic absorption bands of CoTPP except overlapped spectra were 1,069 cm ^-1 . As a result of comparing the above three spectra, it is judged that the mixture of polymer PBMA and CoTPP is well formed.

An SEM image of an experimental example of a hollow fiber membrane for oxygen separation according to Table 2 is shown in FIG. 4 using a scanning electron microscope (SEM, S-4700, HITACHI). (a) PBMA: CoTPP (100: 1 ratio wt.%), (b) PBMA: CoTPP (100: 5 ratio wt.%), (c) PBMA: CoTPP (a) 115 nm, (b) 127 nm, (c) 191 nm and (d) 305 nm depending on the mixing ratios of PBMA: CoTPP (100: 50 ratio wt. The coating layer tended to become thicker. The porosity of the porous tubular polymer membrane ranged from 100 to 300 nm. It was also confirmed that all the membranes had asymmetric structures of the coating layer on the outer surface and the inner tubular porous polymer membrane. Therefore, it is considered that the hollow fiber membrane for oxygen separation of the present invention can improve the permeability and selectivity of the gas.

Example  5 Measurement of oxygen separation function of hollow membrane for oxygen separation

The permeability of oxygen and nitrogen (99.99%, SAFETY GAS, Korea) in the hollow fiber membranes corresponding to Experimental Examples 1 to 4 was measured to measure the oxygen separation function of the hollow fiber membrane for oxygen separation manufactured according to the above-described embodiment . FIG. 5 is a schematic representation of a method for measuring gas permeability. The permeability was measured for each of oxygen (10) and nitrogen (20) under the same conditions as in Table 3. The gas was injected at 0.1 to 1.0 kgf / cm ² , and the permeate side of the separator was kept at atmospheric pressure. The operating temperature was kept constant at 25 占 폚 using the air circulation of the oven (30) in order to balance the feed gas flow with the oxygen separation membrane module. The gas flow rate through the module was measured with a bubble flow meter (40). Gas permeability was calculated using the following equation (1): < RTI ID = 0.0 >

(1)

(One)

Q _p is the permeation flux through the membrane, ΔP is the pressure of the gas passing through the membrane, and A is the membrane area. The unit of P is GPU (1 GPU = 1 x 10 ^-6 cm 3 (STP) / cm ² · cmHg · sec).

The measurement results of the permeability of the gas are shown in Fig. (A) shows oxygen permeability and (B) shows nitrogen permeability. In the case of oxygen permeability, the permeability tended to decrease as the pressure increased over the entire pressure range. In the lowest pressure of 0.1 kgf / cm ² , all four hollow membranes showed the highest permeability. It is considered that as the pressure increases, the oxygen vacancies are saturated in CoTPP and the comparative permeability decreases at high pressure. At a pressure of 1.0 kgf / cm ² , as the ratio of CoTPP in the coating layer increases, it shows a lower oxygen permeability. The coating layer containing CoTPP is thickened and the amount of gas permeated is considered to be reduced. On the other hand, at the pressure of 1.0 kgf / cm ² or less, the highest permeability was shown when PBMA: CoTPP was 100: 5. In the case of nitrogen permeability, it was found that the permeability was higher as the ratio of CoTPP in the coating layer decreased in the entire pressure range. It is considered that nitrogen is not influenced by CoTPP and shows high transmittance only in thin coating layer.

The gas selectivity was calculated using the following equation (2): < RTI ID = 0.0 >

(2)

(2)

a represents the pressure ratio of the two gases i and j, and the pressure ratio is the permeability of each gas, and the ratio thereof represents gas selectivity. The results of gas selectivity are shown in Fig. FIG. 7 (A) shows gas selectivity according to the experimental pressure, and FIG. 7 (B) shows the selectivity at 0.1 kgf / cm ² and 1.0 kgf / cm ² depending on the coating ratio. (A), it can be seen that the selectivity of oxygen / nitrogen is higher than that of oxygen / nitrogen in the entire pressure range. Among them, the highest oxygen selectivity was obtained when PBMA: CoTPP was 100: 50 at 0.1 kgf / cm ² pressure. (B), the higher the ratio of CoTPP in the coating layer at 0.1 kgf / cm ² and 1.0 kgf / cm ² , the higher the selectivity. It can be seen that the oxygen selectivity is generally higher than the pressure of 1.0 kgf / cm ² at a pressure of 0.1 kgf / cm ² .

FIG. 8 shows the results of measurement of permeability and selectivity of carbon dioxide, nitrogen and oxygen using a hollow fiber membrane for oxygen separation coated with a PBMA: CoTPP ratio of 100: 5 according to the above embodiment. (A) is a graph showing the permeability of each gas according to pressure. The permeability of each gas was measured in the same manner as in Fig. 5 and calculated using Equation (1). As a result, the oxygen permeability was the highest at 1.0 kgf / cm ² compared to nitrogen and carbon dioxide. As the pressure increased, the permeability of carbon dioxide and nitrogen increased, but the oxygen tended to decrease relatively. It is considered that as the pressure increases, the oxygen activity of CoTPP decreases, and the comparative permeability decreases at high pressure. (B) shows the selectivity according to the pressure difference between the injected gas (Retentate) and the permeated gas (Permeate) as a result of each permeation experiment for oxygen and nitrogen gas, oxygen and carbon dioxide gas. Both oxygen / nitrogen and oxygen / carbon dioxide exhibit the highest selectivity at the lowest pressure of 0.1 kgf / cm ² . It is considered that the hollow fiber membrane for oxygen separation according to the present invention has high selectivity due to high oxygen permeability at low pressure due to the increase of affinity with oxygen by CoTPP at low pressure. Therefore, it is considered that the hollow fiber membrane for oxygen separation, in which the coating layer containing CoTPP of the present invention is formed, shows better oxygen separation effect at low pressure.

While the present invention has been described in connection with what is presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, .

All technical terms used in the present invention are used in the sense that they are generally understood by those of ordinary skill in the relevant field of the present invention unless otherwise defined. The contents of all publications referred to herein are incorporated herein by reference.

Claims (9)

Porous tubular polymer membrane; And
And a porous coating layer formed outside the tubular polymer membrane,
Wherein the coating layer comprises a transition metal-porphyrin compound and a polymer compound.
A hollow fiber membrane for oxygen separation.
The method according to claim 1,
The polymer membrane and the polymer compound are made of the same or different polymer materials,
The polymer material may be selected from the group consisting of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer or polyvinylidene fluoride One or more selected,
A hollow fiber membrane for oxygen separation.
The method according to claim 1,
The transition metal-porphyrin compound may be at least one selected from the group consisting of Co, Cu, Fe, Ni, Mn, Ru and Rh, Pt, At least one transition selected from the group consisting of lead (Pb), palladium (Pd), zinc (Zn), titanium (Ti), vanadium (V), chromium (Cr), silver (Ag) metal;
A porphyrin ligand selected from porphyrin or tetraphenylporphtrin and
The method of claim 1 wherein the at least one axial ligand is selected from the group consisting of imidazole, pyridine, benzoimidazole, benzopyridine, and benzylimidazole.
A hollow fiber membrane for oxygen separation.
The method according to claim 1,
Wherein the coating layer has a thickness of 0.5 nm to 400 nm,
A hollow fiber membrane for oxygen separation.
As a method of producing a hollow fiber membrane for oxygen separation,
The method comprises the steps of: preparing a spinning solution containing a polymer;
Preparing a porous tubular polymer membrane through the nozzle with the spinning solution;
Preparing a coating solution coated on the porous tubular polymer membrane; And
And coating the coating solution on the porous tubular polymeric membrane,
The step of preparing the coating solution comprises the steps of: preparing a transition metal-porphyrin compound; And
Comprising: mixing said transition metal-porphyrin compound, a polymeric compound, and an organic solvent.
A method for producing a hollow fiber membrane for oxygen separation.
6. The method of claim 5,
The transition metal-porphyrin compound may be at least one selected from the group consisting of Co, Cu, Fe, Ni, Mn, Ru and Rh, Pt, At least one transition selected from the group consisting of lead (Pb), palladium (Pd), zinc (Zn), titanium (Ti), vanadium (V), chromium (Cr), silver (Ag) metal;
A porphyrin ligand selected from porphyrin or tetraphenylporphtrin and
The method of claim 1 wherein the at least one axial ligand is selected from the group consisting of imidazole, pyridine, benzoimidazole, benzopyridine, and benzylimidazole.
A method for producing a hollow fiber membrane for oxygen separation.
6. The method of claim 5,
The spinning solution may contain 10 to 30 wt% of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer, or a polyvinylidene Fluoride, or a mixture of one or more thereof selected from the group consisting of fluoride,
70 to 80% by weight of N-methylpyrrolidone, and
2 to 10% by weight of lithium chloride,
A method for producing a hollow fiber membrane for oxygen separation.
6. The method of claim 5,
Wherein the coating solution comprises a mixture of a transition metal-porphyrin compound and a polymer compound in a weight ratio of 100: 1 to 100: 50,
The polymer compound may be selected from the group consisting of a polysulfone polymer, a polyamide polymer, a polyimide polymer, a polymethacrylate polymer, a polyester polymer, an olefin polymer, a polybenzimidazole polymer or polyvinylidene fluoride One or more selected,
A method for producing a hollow fiber membrane for oxygen separation.
6. The method of claim 5,
Wherein the coating is performed by immersing the porous tubular polymer membrane in a coating solution at 25 캜 to 100 캜 for 1 to 60 seconds and then drying at 50 캜 to 100 캜 and winding with a take-
A method for producing a hollow fiber membrane for oxygen separation.

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