• Membrane Journal
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• v.4 no.1
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• pp.30-37
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• 1994

수소는 여러 기체중에서 분자의 크기가 가장 작고, 막에 의한 분리가 쉬워 기체 막분리 공정 중에서 제일 먼저 개발 상업화되었다. 기체분리막의 발전역사를 살펴보면 1965년 Du Pont사가 polyethylene-terephthalate(PET) 중공사 기체분리 장치를 만든 것이 최초이다. 그러나 이 장치는 시판되지 않았다. 1979년 Monsanto사가 다공성 polysulfone 중공사에 polydimthylsiloxane계 고분자를 박막형태로 도포한 복합막을 개발하여 이것을 이용한 공업적 규모의 수소분리장치(Prism separator)를 개발하였는데 이 장치가 널리 퍼지게 되었다. 이 분리막은 현재 석유화학 및 석유정제공업 플렌드 폐가스로부터 수소회수, Oxo합성 기체중의 $CO/H_2$ 몰비 조절 등의 분야에서 사용되고 있다. 고분자 분리막 공정의 세계 시장 규모가 내년에는 20억~30억불로 추산되며 그 중 기체분리막 공정만 5억불에 달할 것으로 추정하고 있다. 본 논문에서는 수소 분리 회수용 고분자 기체막을 중심으로 분자설계, 공정현황 및 최근 연구동향 등을 살펴보고자 한다.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.03a
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• pp.113-129
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• 1994

수소는 여러 기체중에서 분자의 크기가 가장 작고, 막에 의한 분리가 쉬워 기체 막분리 공정 중에서 제일 먼저 개발 상업화 되었다. 기체분리막의 발전 역사를 살펴보면 1965년 Du Pont 사가 polyethyleneterephthalate(PET) 중공사 기체분리 장치를 만든 것이 최초이다. 그러나 이 장치는 시판되지 않았다. 1979년 Monsanto사가 다공성 polysulfone 중공사에 polyimethylsiloxane계 고분자를 박막형태로 도포한 복합막을 개발하여 이것을 이용한 공업적 규모의 수소분리장치(Prism separator) 를 개발하였는데 이 장치가 널리 퍼지게 되었다. 이 분리막은 현재 석유화학 및 석유정제공업 플랜트 폐가스로부터 수소회수, Oxo합성 기체중의 CO/H$_{2}$ 몰비 조절등의 분야에서 사용되고 있다. 본 논문에서는 수소 분리 회수용 고분자기체막을 중심으로 분자설계, 공정현화 및 최근 연구동향 등을 살펴보고자 한다.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.47-53
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• 2011

$SF_6$ (Sulfur hexafluoride) possesses high GWP (Global Warming Potential) as sepcified by the IPCC (Intergonvernmental Panel of Climate Change). Recently, the recovery-separtion of $SF_6$ research area, including permeation properties studies using various membrane's materials and the practical operation of recovery-separtion using membrane of waste $SF_6$ gas is in the initial state. The separation efficiency of a single $SF_6$ and waste $SF_6$ mixture was evaluated using a PSF (polysulfone), PC (tetra-bromo polycarbonate) and PI (polyimide) hollow fiber membranes. According to the results of single gases permeation properties, PI membrane has the highest permselectivity of $N_2$ gas in $N_2/SF_6$ gas. Under the condition of P=0.5 MPa, the highest concentration of recovered $SF_6$ is 95.6 vol % in the separation experiment of $SF_6/N_2$ mixture gas by PC membrane. Under the operation pressure of P=0.3 MPa at a fixed retentate flow rate fixed of 150 cc/min, the maximum recovery efficiency of $SF_6$ is up to 97.8% by PSF membrane. From the results above, it is thought that the separation and recovery technique of $SF_6$ gas using membrane will be used as the representative eco-technology in the $SF_6$ gas treatment in the future.

• Membrane Journal
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• v.27 no.1
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• pp.60-67
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• 2017

Recently, the economic, social and environmental significance of the water industry is increasing significantly due to rapid global urbanization, population growth, and imbalance in demand and supply of water resulted by climate change. The type of these water industries are all different and they can be distinguished by the kinds of membranes used. Mainly, polymer materials that have excellent physical and chemical stability are used, but recently various methods of assigning hydrophilicity have been introduced due to their hydrophobic properties. In this study, hydrophilic polymers of four types were introduced into a commercially available hollow support to assign hydrophilicity. Furthermore, the morphology of the coated hollow support through FE-SEM was confirmed as well. Also the contact angle was measured to examine the degree of hydrophilicity of the coated hollow support with each polymer. Finally,.effect of different time on water permeability as well as the relationship between water permeability and hydrophilic polymers were investigated. As a result, the coating with 1 wt% of pluronic has good hydrophilicity degree, and shows the excellent water permeability without blocking the pore of the hollow fiber. Therefore, it can be concluded that the hydrophilic coating using pluronic polymer is most suitable as the water treatment.

• Membrane Journal
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• v.22 no.1
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• pp.54-61
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• 2012

To separate and recover of VOCs, supporting membranes using PEI were prepared by phase separation method and it was coated with PDMS to prepare PEI-PDMS hollow composite membrane. To investigate characteristic of prepared membrane, pure gas permeability was measured using oxygen and nitrogen, the stage cut and permeance property with feed concentration were evaluated using xylene, ethyl benzene, toluene and cyclohexane. Also, to check solvent resistance on VOCs, stress-strain property of membrane with immersion time in solvent were measured by DMA. The permeance value of $O_2$ and $N_2$ showed 63 GPU and 30 GPU respectively. Permeated VOCs concentration was decreased with increasing stage cut. But, conversely, recovery efficiency that was increased with increasing stage cut. As a result of DMA test, the stress and strain were 11.93 MPa and 13.52%, respectively.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.32-33
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• 1997

중공사막은 제조과정인 wet spining의 과정에서 defect가 형성될 수 있어 분리선택도에 큰 영향을 미친다. 이러한 defect의 처리 방법으로는 dipping method등의 방법이 현재 널리 쓰이고 있다. dipping method는 제조된 중공사막을 PDMS 등의 고분자용액 속으로 통과시켜 결과적으로 중공사막 표면에 얇은 고분자막이 형성되도록 하는 방법이다. 그러나 이러한 방법으로 중공사 막을 처리할 경우 고분자 용액이 pore내로 침입하거나 중력으로 인하여 용액이 아래쪽으로 몰려 하반부의 두께가 두꺼워진다는 단점이 있다. 본 연구에서는 플라즈마 반응기 내의 전극사이의 공간에서 substrate의 위치를 변화시켜가면서 thickness를 측정하여 중공사막의 plasma coating을 위한 기초 자료를 정립하여 중공사막 plasma 표면처리 장치 개발에 기여하고자 한다.

• Membrane Journal
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• v.21 no.1
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• pp.98-105
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• 2011

Cellulose triacetate (CTA) polymer among cellulose esters were used for preparing hollow fiber membranes by phase separation method to investigate the gas permeation properties. To endow gas separation properties, 1,4-dioxane and LiCl were used as additives in the polymer dope solution. The spinning conditions including spinning temperature were controlled to form an active skin layer on the hollow fiber surface. Scanning electron microscopy was used to examine morphology of surface and cross section of the prepared CTA hollow fibers. The gas permeation performance of CTA hollow fiber membranes showed $P_{CO2}$ = 17 GPU and ${\alpha}_{CO2/N2}$ = 48.

• Membrane Journal
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• v.15 no.2
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• pp.157-164
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• 2005

In this study, composite hollow fiber membranes were developed for the recovery of olefin monomers in polyolefin industry off-gases. Polyetherimide (PEI) hollow fiber support membranes were fabricated from spinning solutions containing PEI, NMP and polyethylene glycol (PEG). The influence of dope solution and inner coagulant composition on the permeation properties and structure of hollow fiber supports was examined. PDMS was used as a selective layer and coated on PEI hollow fiber support. The thickness of active layer was controlled by changing coating solution concentration. The permeation properties of hollow fiber supports and composite membranes were characterized with a pure gas permeation test. The optimized composite hollow fiber membrane has $10\;{\mu}m$ selective layer and shows excellent separation performance; the ideal selectivity of olefins over nitrogen is in the following order: 1-butylene (6.4) > propylene (17) > ethylene (97), which selectivity data are similar to the intrinsic olefin/nitrogen selectivities of PDMS. This confirms that the new composite hollow fiber membranes suitable for olefin off-gas recovery has developed successfully.

• Membrane Journal
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• v.22 no.1
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• pp.23-34
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• 2012

In this study, we investigated the permeation property of single gases ($N_2$, $O_2$, $SF_6$, $CF_4$ through hollow fiber polymeric membrane (PSF, PC, PI) as a function of pressure and temperature to decide operating condition for $SF_6$ gas separation process. The results showed the gas permeation varied differentlydepending on the properties of gases and membrane. When permeance of each gases was represented as a function of temperature and pressure in 3 dimensional space, the surface of permeance was shown approximately flat. Thus, we established permeance models with forms of first-and second-order polynomial. These two models showed high goodness of fit. This indicates that the two polynomial models have enough applicability to predict the gas separation process.

• Membrane Journal
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• v.31 no.5
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• pp.363-370
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• 2021

Organic solvent resistant hollow fiber membranes were fabricated via a thermally induced phase separation (TIPS) method using Polyketone polymer, a material with excellent resistance to organic solvents. The PEG300, DMSO₂ and Glycerine called the "green solvents" were used as diluents for TIPS method. The spherulite structure was formed with DMSO₂ by S-L phase separation behavior whereas the bicontinuous structures were formed with PEG300 and Glycerine, respectively. The morphology of the PK hollow fiber membranes was investigated using SEM. The pure water permeability and the durability test were conducted to understand the permeation properties of PK hollow fiber membranes. The tensile strength test was conducted for the property of mechanical strength. In this study, the fabrication of PK hollow fiber membranes with various diluents was discussed to understand the correlation between diluent and polymer in detail.