• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.93-94
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• 1998

1. 서론 : 폴리아크릴로니트릴(PAN)은 폴리술폰에 비해 친수성을 가지고 있어 분리막에 응용시, 오염이 덜 되는 장점을 갖고 있어 폐수처리, 중수도 처리 등의 응용에서 우수한 막재료로 알려져 있다. 또한 기체분리 및 투과증발 복합막 제조시의 지지체로서도 많이 사용되고 있다. PAN을 재료로 다공성 비대칭막을 제조할 때는 상 전환 법을 이용하게 되는데, 이때 막재료로 사용되는 고분자는 용매에 용해시켜 고분자 용액을 제조하여 지지체 위에서 casting한 후, 비용매에 침적시켜 막을 제조하게 된다. 이때 최종 생성되는 막의 형태는 고분자 용액의 농도, 용액내의 용제의 조성, 비용매의 조성등에 의해 영향을 받게 된다. 그러므로 막의 성능은 위의 요소의 조절에 따라 커다란 변화가 이루어진다.

• Membrane Journal
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• v.21 no.2
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• pp.177-192
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• 2011

Hollow fiber membrane using CTA polymers were prepared by the phase separation method for the separation and purification of biogas and the hollow fiber gas separation membrane modules with the effective surface area of 0.17 $m^2$ were prepared. The pure gas permeation properties of membrane modules for methane, oxygen and carbon dioxide were measured. The permeance of $CO_2$ and $CH_4$were 0.46 GPU and 18.52 GPU, respectively, therefore, the high $CO_2$/$CH_4$ selectivity of 40.4 was obtained. The separation and purification test for 4 different simulated mixed gases were carried out after the pure gas test and the gas concentration and flux of the permeate at the various stage-cut were measured from the 1 stage, 2 stage, and 3 stage cascade of membrane modules. In the 1 stage test, the concentration of $CH_4$ increased as the increase of the stage-cut, while the $CH_4$ recovery efficiency ratio decreased. In the 2 stage test, the $CH_4$ recovery efficiency ratio increased compared to the 1 stage. The 3 stage test was employed to reduce the loss of $CH_4$ in biogas and the result showed less than 5% of $CH_4$ recovery loss.

• Membrane Journal
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• v.17 no.2
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• pp.134-139
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• 2007

Experimental and numerical analysis were performed for separation of carbon dioxide from carbon dioxide and nitrogen gas mixture using a polyethersulfone hollow fiber membrane. The experimental results were compared with those obtained at the same operating condition by the numerical analysis. It was observed that there was a big difference between the experimental results and those by a numerical analysis where the permeance of carbon dioxide and its ideal selectivity over nitrogen were obtained from the pure gas permeation. Therefore, the permeance of carbon dioxide and its selectivity were obtained from the separation experimental results using the numerical analysis as a function of the mole fraction of carbon dioxide, the feed pressure and the permeate pressure in the gas mixture. The results of the numerical analysis using the selectivity obtained from the gas mixture were in good agreement with those of the experimental.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.77-79
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• 1994

폐수와 하수처리에서 양질의 재생수를 얻기위하여 고분자막을 이용한 폐수재활용에서 나타나는 공정상 문제점을 고찰하였다. 본 연구에서 사용한 폐수는 처탑공장의 폐수로서 RO막을 이용한 폐수의 재이용공정개발을 목표로하고 있으며, pilot실험을 토대로 폐수의 적용성 검토가 행하여졌다. 사용된 막의 종류는 중공사막형의 막으로서 막내의 층류 흐름의 응용은 투석막, 기체분리, 중금속의 추출등 상당한 관심속에 있다. 여기서 중공사막과 같은 관(Cynlindrical)형의 막 구조에서 물질과 에너지 이동현상은 막분리공정을 이해하는 중요한 물리적고찰로서 막투과도를 높힐수 있을 뿐만 아니라 운전온도에 의해 중공사막 RO막내의 유량변화에 주요한 변수가 될 수 있다.

• Membrane Journal
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• v.17 no.4
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• pp.352-358
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• 2007

A nonporous hollow fiber membrane contactor was used to control the concentration of oxygen dissolved in an aqueous solution, which was predicted along the hollow fiber membrane using a computer simulation. The governing ordinary differential equations were derived for the occurrent flows of the feed aqueous solution and the feed gas mixture in a membrane contactor and they were numerically solved using the 5th Runge-Kutta-Verner method with a personal computer, where the program was coded utilizing a software of the Compaq Visual Fortran 6.6. It is found that the concentration of oxygen dissolved in water increases from 30 to 64 ppm as the length of the hollow fiber increases from 0.4 to 1.2 m when the membrane of fibers are equal to be 16,000; the flow rate of the feed gas is kept to be 0.536 mol/sec; its pressure is maintained to be 486 kPa; the flow rate of the water is 16.69 mol/sec. As the flow rate of the water increases from 9.26 to 26.85 mol/sec, the concentration of oxygen decreases from 40 to 20 ppm with the constant fiber length of 0.4 m. Finally, it is observed that the concentration of oxygen increases from 33 to 69 ppm as the pressure of the feed gas increases from 298 to 847 kPa.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.45-46
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• 1994

기체분리막의 성능을 평가하기 위한 Manometric method의 몇가지 투과측정장치 중, High-Vacuum technique는 기체 투과계수, 확산계수 및 용해도계수의 정확한 값을 얻는데 가장 유용한 장치이다. 그러나 이 장치는 비용이 비싸고, 조작법이 복잡하며, 투과실험시 계 내의 투과측의 농도를 분석할 수 없고, 측정시간이 많이 걸리는 단점이 있다. 따라서 보다 간단하고 일반적인 측정장치는 막내 기체 확산계수의 측정에는 정확도가 떨어지지만, Low-Vacuum Technique 측정장치가 더 많이 사용되고 있다. Volumetric method는 조작법이 간단하며, 계 내의 농도분석이 가능하고, 측정시간이 빠르며, 비용이 적게 드는 장점이 있다. 일반적으로 Volumetric 투과특정장치로 투과계수는 얻었지만, 확산계수에 대해서는 극소수의 연구자들만이 언급하고 있다. 이는 실험하는 방법의 어려움과 기체의 막내 농도분포에 대해 수학적으로 적합한 모델의 해를 얻지 못한데 있다. 최근데 Lee 등은 Volumetric method을 이용한 확산계수의 평가에 대해 연구하여 신뢰성 있는 결과를 보여주었다. 따라서 본 실험은 Volumetric method를 이용하여 막내 기체 확산계수의 측정을 위해 온도, 압력및 분자직경에 따라 Standing time의 예측에 대해 검토하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.71-72
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• 1997

1. 서론 : 공기중의 산소분리용 고분자막은 높은 선택도를 동시에 요구한다. 이 두가지 조건을 만족시키는 소재 개발과 기존의 고분자물질을 수식하는 연구가 진행되고 있다. 고분자막에 대한 수식방법으로는 UV처리, plasma처리등이 있으나, 이들 방법은 선택도는 증가시키나 투과도를 감소시키는 경향이 있다. 기체의 투과저항을 줄이기 위하여 다공성 지지체 위에 박막을 입힌 복합막과 박막의 skin layer와 sub-layer를 갖는 비대칭막은 투과저항을 줄일수 있으나 선택도는 고분자 고유의 80%정도까지 감소되는 것으로 알려졌다. 본 연구의 목적은 고분자 복합막의 투과분리특성을 향상시키기 위한 것으로 지지층의 세공과 표면에 실리카/고분자를 충전, 피복시켜 투과분리특성을 조사하였다. 현재까지의 연구는 낮은 투과계수와 높은 선택도를 갖는 고분자물질이 사용되었으나, 본 연구에서는 폴리이미드로는 폴리이미드 중에서 투과계수가 가장 높다고 알려진 6FDA-p-TeMPD[{(3,3',4,4'-dicarboxyphenyl)hexafluoropropanedianhydride}-{2,3,5,6-Tetra-methyl-1,4-phenylenediamine}] 폴리이미드를 택하였으며 다공성지지체는 aluminum oxide를 사용하였다 . 본 실험에서는 선택도와 투과속도에 주로 영향을 미치는 폴리이미드와 실리카의 양에 대하여 고찰하였다.

• Membrane Journal
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• v.25 no.3
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• pp.223-230
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• 2015

We synthesized novel polyimides with high gas permeability and selectivity for application of gas separation membrane. 2,2-bis(3,4-carboxylphenyl) hexafluoropropane dianhydride (6FDA) and two kinds of amines with high permeability and solubility were used to prepare the novel polymide. 2,4,6-Trimethyl-1,3-phenylenediamine (DAM) was used to improve gas permeability and 4,4-Methylenedianiline was used to improve the gas selectivity respectively. The polyimide copolymers were synthesized by commercial chemical imidization method using Triethylamine and Acetic anhydride and their average molecular weights were over 100,000 g/mol. The glass temperature (Tg) and the thermal degradation temperature were characterized using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The synthesized copolymers showed high Tg over $300^{\circ}C$ and high thermal degradation temperature over $500^{\circ}C$. The gas permeation properties were measured by time-lag equipment. Although general polyimides showed very low gas permeability, synthesized polyimide copolymer showed high $O_2$ permeability of 10.1 barrer with high $O_2/N_2$ selectivity around 5.3. From this result, we confirm that these membranes have possibility to apply to gas separation membrane.

• Membrane Journal
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• v.22 no.3
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• pp.224-233
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• 2012

To improve permeation performance of gas separation membrane, polysulfone hollow fiber membrane was prepared by wet-dry phase inversion method using Triton X-100 as non-ionic additive. And variation of gas permeation behavior by additive was investigated. Various spinning conditions such as air gap, concentration of polymer, dope tank temperature were controlled and these effects were studied. The morphology and gas permeation property of hollow fiber membranes were investigated using scanning electron microscope (SEM) and bubble flow meter respectively. We confirmed that the membranes added with Triton X-100 had a smooth external skin at various air gap length conditions. The macrovoids of these hollow fiber membranes were more developed with increase of air-gap from 4 to 90 cm and that induced higher permeance. The permeance of polysulfone membranes has the higher value at comparatively lower concentration polymer (30 wt% polysulfone) and lower concentration of additive (15 wt% Triton X-100). When temperature in dope tank was controlled, the membranes prepared at $100^{\circ}C$ showed low permeance because of volatilization of additive and solvent.

• Polymer(Korea)
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• v.32 no.6
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• pp.593-597
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• 2008

To separate carbon dioxide from a flue gas, membranes for gas separation was fabricated from polystyrene-b-polybutadiene (SB) diblock copolymer blends with poly(phenylene oxide), PPO. SB diblock copolymer formed miscible blends with PPO in the experimental range (lower than or equal to 70 wt% PPO). When the blend contained PPO whose composition is in the range of 40-50 wt%, the discontinuous phase of polybutadiene block in SB diblock copolymer, was changed to discrete phase, while polystyrene blocks containing PPO was changed to the continuous phase. A sudden decrease of the gas permeability and a sudden increase of the gas selectivity was observed at these blend compositions. A gas separation membranes having excellent mechanical properties and exhibiting advantages in gas permeability and selectivity could be fabricated from blends containing more than 50 wt% PPO.