분리막 접촉기용 Poly(vinylidene fluoride) 중공사막 제조 및 투과특성

박유인 ( Park Yu In ),이기섭 ( Lee Gi Seob ),연순화 ( Yeon Sun Hwa ),서봉국 ( Seo Bong Gug ),임지원 ( Im Ji Won ),이규호 ( Lee Gyu Ho ) 한국공업화학회 2003 공업화학 Vol.14 No.6

상전이 공정을 이용하여 분리막 접촉기용 비대칭 다공성 poly(vinylidene fluoride) (PVDF) 중공사막을 제조하였다. 용매로는 dimethylacetamide (DMAc)를 사용하였으며 기공 형성제로는 LiCl를 사용하였다. 또한 중공사막 제조시 내부 응고제로는 물, 에탄올/물 및 DMAc/물 혼합액 등을 사용하였으며 외부 응고제로는 물을 사용하였다. 상전이 과정에서 기공 형성제 및 내부 응고제(비용매)가 막의 구조에 미치는 영향을 살펴보았다. 제조된 PVDF 중공사막의 구조는 주사전자현미경(SEM)을 이용하여 확인하였으며 기공크기와 유효표면 기공율은 기체 측정법(Gas Permeation Method)을 이용하여 알아보았다. 그 결과 이 중 스킨의 비대칭구조로서 0.02~0.04 ㎛ 범위의 기공크기를 갖는 PVDF 중공사막을 제조하였다. 또한 제조된 PVDF 중공사막에 대해 물리적 흡수제로 물을 사용하여 기체 및 흡수제의 유속에 따른 이산화탄소의 분리효율을 알아보았다. 현재 분리막 접촉기로 많이 사용되어지고 있는 대칭 다공성 구조의 Polypropylene(PP) 중공사막과 본 연구를 통해 제조된 비대칭 다공성 PVDF 중공사막에 대해 이산화탄소 분리효율을 비교ㆍ분석한 결과 비대칭 다공성 PVDF중공사막 접촉기가 단위 표면적당 높은 이산화탄소 흡수효율을 나타내었다. Asymmetric porous polyvinylidene fluoride(PVDF) hollow fiber membranes for membrane contactor were prepared by a wet phase inversion method. In spinning these PVDF hollow fibers. dimethylacetamide (DMAc) and LiCl were used as a solvent and a pore-forming additive. respectively. Pure water, water/ethanol or water/DMAc mixture was used as an internal coagulant, while water was an external coagulant. The characteristics of the phase inversion process were studied during the formation of the PVDF membrane, expecinlly the effect of pore-forming additive and internal coagulants (non-solvent) addition on the membrane structure. The cross- sectional structure of the prepared PVDF hollow fiber membranes was examined by scanning electron microscopy (SEM). The Average pore size and effective surface porosity were determined using the gas permeation method. The pore size the prepared asymmetric PVDF hollow fiber membrane was in the ragne of 0.02-0.04 μm. The carbon dioxide separation performances with the change of flow rates of absorbent and mixed gas were studied, using the PVDF hollow fiber membrane water as a physical absorbent. The performances of the asymmetric porous WDF hollow fiber membrane and a symmetric commercialized one made from PP were compared. As a result, the asymmetric porous PVDF hollow fiber membrane showed higher separation efficiency of CO_(2) per unit surface areas than the symmetric porous PP hollow fiber membrane.

Study on CO₂ absorption performance of lab-scale ceramic hollow fiber membrane contactor by gas/liquid flow direction and module design

Lee, Hong Joo,Park, Yu Gang,Kim, Min Kwang,Lee, Seung Hwan,Park, Jung Hoon Elsevier 2019 Separation and purification technology Vol.220 No.-

<P><B>Abstract</B></P> <P>Membrane contactor has been actively studied in recent years, but it is difficult to modulate the ceramic hollow fiber membranes because they are extremely brittle and poor in flexibility. For this reason, research on ceramic hollow fiber membrane contactor modules has been rarely carried out. In this study, hydrophobic modified ceramic hollow fiber membranes were fabricated by phase inversion method. 1-in. unit module, a 3-parallel connection module, and a 2.5-in. advanced module with the ceramic hollow fiber membranes were developed. A membrane contactor CO<SUB>2</SUB> capture system with the module was set up and characteristics of ceramic hollow fiber membrane contactor were analyzed. The highest CO<SUB>2</SUB> absorption property was observed in the configuration in which the liquid flows on the shell side from the bottom to the top, and the gas and the liquid contacts in the counter-current. In addition, a lab-scale ceramic hollow fiber membrane contactor unit module was successfully developed to treat 0.175 Nm<SUP>3</SUP>/h flue gas with 90% CO<SUB>2</SUB> removal efficiency. To the best of my knowledge, this is the first case of CO<SUB>2</SUB> absorption experiment using hydrophobic ceramic hollow fiber membrane contactor module instead of the polymeric membrane module or single ceramic membrane. These results are expected to be very valuable as fundamental and important data for scale-up of ceramic membrane contactor process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The ceramic hollow fiber membrane contactor (HFMC) modules were prepared. </LI> <LI> The performance of Longitudinal-flow and Cross-flow module was compared. </LI> <LI> Effect of configuration of the HFMC modules on CO<SUB>2</SUB> absorption was studied. </LI> <LI> The guidelines to scale-up factor of the ceramic HFMC module were suggested. </LI> </UL> </P>

Hollow fiber membrane model for gas separation: Process simulation, experimental validation and module characteristics study

파이잔아흐마드,K.K. Lau,S.S.M. Lock,Sikander Rafiq,Asad Ullah Khan,이문용 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Conceptual process simulations and optimization are essential in the design, operation andtroubleshooting stages of a membrane-based gas separation system. Despite this, there are fewmathematicalmodels/tools associated with a hollow fiber membrane module available in a commercialprocess simulator. A mathematical model dealing with the hollow fiber module characteristics that canbe included within a commercial process simulator is needed to examine the performance andeconomics of a gas separation system. In this study, a hollow fiber membrane modelwas incorporated inAspen HYSYS as a user defined unit operation for the study of carbon dioxide separation from methane. The hollow fibermembrane model was validated experimentally. The study of a double stage membranemodule with a permeate recycle, which was proposed to be the optimal configuration in previousstudies, was extended to consider the effects of the module characteristics (such as the fiber length,radius of the fiber bundle, diameter of the fibers, and porosity) on the process performance andeconomics. The gas processing cost (GPC) increased with increasing fiber length and bundle radius, anddecreased with increasing outer diameter of the fibers and porosity. At the same time, the separationefficiency (product quality) was also dependent on these module parameters. Therefore, the tradeoff forthe hollow fiber membrane module characteristics needs to be determined based on the minimum GPCwith respect to the desired product purity.

PVDF와 PP 중공사막 접촉기를 이용한 Alkanolemine 수용액의 이산화탄소 흡수 분리 특성

연순화 ( Sun Hwa Yeon ),서봉국 ( Bong Kuk Sea ),이기섭 ( Ki Sub Lee ),박유인 ( You In Park ),이규호 ( Kew Ho Lee ) 한국공업화학회 2002 공업화학 Vol.13 No.8

중공사막 접촉기를 기존의 흡수장치에 흡수기로 도입하여 구축한 hybrid 시스템을 이용하여 이산화탄소의 분리효율과 흡수제에 대한 중공사막의 물리ㆍ화학적 안정성에 관한 연구를 수행하였다. 서로 다른 구조적 특성을 지니는 PVDF 중공사막과 PP 중공사막을 사용하여 흡수제 MEA, TEA, MDEA 수용액의 이산화탄소 분리효율을 측정하였다. 또한 위의 흡수제에 대한 막의 물리적 그리고 화학적 안정성을 막의 젖음성(wettibility)과 IR 분석을 통해 분석한 결과, MEA와 MDEA 수용액의 경우 PVDF 막에서 물리ㆍ화학적 불안정성을 보였다. 각 흡수제에 대한 long-term 실험을 실시한 결과 3급 아민인 TEA 수용액의 경우 가장 오랜 시간 동안 steady-state 상태를 유지하였다. TEA 수용액에 소량의 MEA를 첨가한 혼합 흡수제의 경우 상당한 분리효율의 상승을 기대할 수 있으며, 막의 pore 내에서 안정적 기-액 계면의 형성으로 인하여 장기간 안정적 운전이 가능하므로 중공사막의 적합한 흡수제로 기대된다. A hollow fiber membrane contactor-stripper hybrid process was used to recover CO_2 from the flue gas, and the physical and chemical stability test of hollow fibers against alkanolamine-based absorbents was conducted. The CO_2 removal efficiency of the polyvinylidenefluoride (PVDF) and polypropylene (PP) hollow fiber membrane contactor was tested with aqueous monoethanolamine (MEA), triethanolamine (TEA) and methyl-diethanolamine (MDEA) absorbents. For MEA, the hollow fibers showed a high CO_2 removal efficiency, but poor chemical and physical stability because the MEA absorbent chemically attacked fibers or physically well penetrated into fiber`s pores. For TEA, the hollow fibers showed a low CO_2 removal efficiency, but good chemical and physical stability. In the case of mixed absorbent adding MEA to aqueous TEA solution, CO_2 removal efficiency of the hollow fiber membrane contactor was enlargd, and this mixed absorbent made it possible to operate this system under long term steady-state conditions due to creating stable liquid-gas interface among the fiber`s pores.

Hollow fiber membrane model for gas separation: Process simulation, experimental validation and module characteristics study

Ahmad, Faizan,Lau, K.K.,Lock, S.S.M.,Rafiq, Sikander,Khan, Asad Ullah,Lee, Moonyong Elsevier 2015 Journal of industrial and engineering chemistry Vol.21 No.-

<P><B>Abstract</B></P> <P>Conceptual process simulations and optimization are essential in the design, operation and troubleshooting stages of a membrane-based gas separation system. Despite this, there are few mathematical models/tools associated with a hollow fiber membrane module available in a commercial process simulator. A mathematical model dealing with the hollow fiber module characteristics that can be included within a commercial process simulator is needed to examine the performance and economics of a gas separation system. In this study, a hollow fiber membrane model was incorporated in Aspen HYSYS as a user defined unit operation for the study of carbon dioxide separation from methane. The hollow fiber membrane model was validated experimentally. The study of a double stage membrane module with a permeate recycle, which was proposed to be the optimal configuration in previous studies, was extended to consider the effects of the module characteristics (such as the fiber length, radius of the fiber bundle, diameter of the fibers, and porosity) on the process performance and economics. The gas processing cost (GPC) increased with increasing fiber length and bundle radius, and decreased with increasing outer diameter of the fibers and porosity. At the same time, the separation efficiency (product quality) was also dependent on these module parameters. Therefore, the tradeoff for the hollow fiber membrane module characteristics needs to be determined based on the minimum GPC with respect to the desired product purity.</P>

국내 장기 운전 정수처리용 Hollow fiber 저압 막 Autopsy 결과 분석 연구

윤석민,이영주,김성수,최한봉,박노석 대한환경공학회 2022 대한환경공학회지 Vol.44 No.9

Objectives: In this study, membrane autopsy was performed for a parallel arrayed low-pressure membrane (microfiltration) filtration process that is actually applied to water treatment, to check out whether there are differences in the degree of membrane fouling due to the uneven flow rate into each module. Also, membrane foulants were evaluated quantitatively. Methods : In this study, autopsy was performed for over 10 year old membranes used for drinking water purification. In this way, the outer casings of membrane modules at different positions were disassembled and visually observed. In addition, In addition, the size of the pores and the porosity were investigated by taking a SEM (Scanning Electron Microscope) photograph for the new and the used membrane module fiber samples in different positions from the header pipe. The used membrane foulants were classified into organic and inorganic matters and quantitatively analyzed. Results and Discussion : As a result of visually observing inside the membrane module that has produced drinking water for over 10 years, the inside of the No. 1 membrane module close to the inlet was contaminated with black foulants. On the other hand, in the case of No. 10 membrane module located farthest from the header pipe inlet, no foulants were observed with the naked eye. Also, it was observed from SEM photograph results that there were large differences in the surfaces among No. 1, 4, 6, 8 and 10 MF module fibers. Conclusion : Even after periodic physical and chemical cleaning, it was concluded that the fouling levels were different each other in the parallel arrayed low-pressure membrane modules. In addition, the pore size distribution and porosities of the membrane modules may vary depending on the position. 목적 : 본 연구에서는 실제 정수처리에 적용되고 있는 외압식 저압막(정밀여과막, Microfiltration) 여과 공정을 대상으로 각 모듈로 유입되는 유량 불균등으로 인한 막 오염의 정도에 차이가 있는지 autopsy 과정으로 확인하고 막 오염물질을 정량적으로 평가하고자 하였다. 방법 : 본 연구에서는 10년 이상 정수 생산에 이용된 막을 대상으로 autopsy를 수행하였다. 그 방법으로 먼저 외피 케이스를 분해하여 육안 관찰하였다. 또한 새 막과 헤더 배관에서 위치가 상이한 10년 이상 사용한 막 모듈 fiber를 채취하여 SEM(Scanning Electron Microscope) 사진을 촬영하여 공극의 크기 및 공극률을 조사하였다. 사용 막 오염물을 유기물과 무기물로 구분하여 정량 분석하였다. 결과 및 토의 : 10년 이상 정수를 생산한 막 모듈 내부 오염 정도를 육안 관찰한 결과 유입구에서 가까운 No. 1 막 모듈 내부에 육안으로도 확인되는 검은색의 오염물로 오염되었다. 이에 반해 헤더 배관에서 가장 멀게 위치한 No. 10 막 모듈의 경우 오염물이 육안 관찰되지 않았다. 또한 10년 이상 사용한 No. 1, 4, 6, 8 그리고 10 MF 막 간에도 표면에 큰 차이가 있는 것으로 관측되었다. 결론 : 주기적인 물리적 및 화학세정을 하더라도 병렬로 배열된 저압막의 경우 각각의 모듈의 오염 정도가 서로 상이하다는 결론을 얻었다. 또한, 유입헤더 배관을 중심으로 병열 배치된 막 모듈의 경우 위치에 따라서도 막의 표면 및 공극의 크기가 달라질 수 있다.

분리막 종류에 따른 하수의 생물학적 고도처리 효율 비교 연구

박종부 ( Jong Bu Park ),신경숙 ( Kyung Sook Shin ),허형우 ( Hyung Woo Hur ),강호 ( Ho Kang ) 한국물환경학회 2011 한국물환경학회지 Vol.27 No.3

This study was performed to investigate the characteristics of nutrient removal of municipal wastewater in the membrane bioreactor system with the different types of membrane. Membrane bioreactor consists of three reactors such as two intermittent anaerobic and the submerged membrane aerobic reactor with flat sheet and hollow fiber membrane, respectively. The removal efficiencies of COD(Cr), BOD, SS, TN and TP on the flat sheet membrane bioreactor were 94.3%, 99.0%, 99.9%, 70.3% and 63.1%, respectively. In addition, The removal efficiencies of COD(Cr), BOD, SS, TN and TP on the hollow fiber membrane bioreactor were 94.0%, 99.3%, 99.9%, 69.9% and 66.9%, respectively. The estimated true biomass yield, specific denitrification rate (SDNR), specific nitrification rate (SNR) and phosphorus removal content on the flat sheet membrane bioreactor were 0.33 kgVSS/kgBOD·d, 0.043 mgNO3-N/mgVSS·d, 0.031 mgNH4-N/mgVSS·d, and 0.144 kgP/d, respectively. In addition, the estimated true biomass yield, specific denitrification rate (SDNR), specific nitrification rate (SNR) and phosphorus removal content on the hollow fiber membrane bioreactor were 0.30 kgVSS/kgBOD·d, 0.067 mgNO3-N/mgVSS·d, 0.028 mgNH4-N/mgVSS·d, and 0.121 kgP/d, respectively. There was little difference between the flat sheet and hollow fiber on the nutrient removal efficiencies except SNR and SDNR. These differences between them were caused by the air demand to prevent the membrane fouling. The flux and oxygen demand for air scouring were 19.0 L/m2/hr and 2.28 m3/min for the flat sheet membrane, and 20.7 L/m2/hr and 1.77 m3/min for the hollow fiber membrane on an average.

Wet CO₂/N₂ permeation through a crosslinked thermally rearranged poly(benzoxazole-<i>co</i>-imide) (XTR-PBOI) hollow fiber membrane module for CO₂ capture

Lee, Jung Hyun,Lee, Jongmyeong,Jo, Hye Jin,Seong, Jong Geun,Kim, Ju Sung,Lee, Won Hee,Moon, Jongho,Lee, Dahun,Oh, Woong Jin,Yeo, Jeong-gu,Lee, Young Moo Elsevier 2017 Journal of membrane science Vol.539 No.-

<P><B>Abstract</B></P> <P>Recently developed crosslinked-thermally rearranged (XTR) polymeric membranes, which show enhanced gas separation, are applicable for CO<SUB>2</SUB> separation from post-combustion gases. Moreover, the resulting thermally rearranged polybenzoxazole (TR-PBO) structure that is thermally induced from hydroxyl-polyimides (HPI) provides high thermal and chemical resistance, which is favorable for gas separation applications containing condensable gases such as water vapor. Herein, the influence of water vapor on the CO<SUB>2</SUB> capture efficiency was evaluated using XTR poly(benzoxazole-<I>co</I>-imide) (XTR-PBOI) hollow fiber membrane modules which were compared with crosslinked HPI (XHPI) in mixture gas and single gases for CO<SUB>2</SUB> and N<SUB>2</SUB>. The results revealed that the permeate CO<SUB>2</SUB> flow rate in the hydrophobic XTR-PBOI module showed enhanced separation performance, whereas the flow rate severely decreased in the relatively hydrophilic XHPI module, reflecting more significant capillary condensation effect in the XHPI membranes. Both membrane modules showed excellent plasticization resistance, and the XTR-PBOI hollow fiber membrane module presented reasonable long-term stability over 240h.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of water vapor in CO<SUB>2</SUB> capture using an XTR-PBOI hollow fiber membrane module. </LI> <LI> XTR hollow fiber membrane modules were compared in a simulated wet flue gas system. </LI> <LI> Capillary condensation in porous substructure changed membrane performance under wet conditions. </LI> <LI> The CO<SUB>2</SUB> capture efficiency, CO<SUB>2</SUB> purity and recovery drastically enhanced in the presence of water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Conceptual image of wet-mixed gas transport (left), relative permeate CO<SUB>2</SUB> and N<SUB>2</SUB> flow rate (middle) in XHPI and XTR-PBOI hollow fiber membranes, and long-term stability (right) of XTR-PBOI membranes.</P> <P>[DISPLAY OMISSION]</P>

N₂/NF₃ 분리용 폴리썰폰 중공사막 제조 연구

임민수,김성중,강하성,박호범,남승은,박호식,이평수,박유인,Lim, Min Su,Kim, Seong-Joong,Kang, Ha Sung,Park, Ho Bum,Nam, Seung Eun,Park, Ho Sik,Lee, Pyung Soo,Park, You In 한국막학회 2016 멤브레인 Vol.26 No.1

Fabrication of polysulfone (PSf) hollow fiber membranes was investigated for the separation of $N_2/NF_3$ gas mixtures, which are emitted from the display and the semiconductor industries. A combination of the non-solvent induced phase separation (NIPS) and the vapor-induced phase separation (VIPS) technique was applied to develop high flux hollow fiber membranes. Thin polymer layers were further coated onto the surface of the hollow fiber membranes by using polydimethylsiloxiane (PDMS) or Teflon AF1600(R), which contributes to improve the $N_2/NF_3$ selectivity. The $N_2/NF_3$ separation performances of our PSf hollow fiber membranes were determined by the intrinsic properties of coating materials. Especially, the PSf hollow fiber membrane coated with Teflon AF 1600(R) exhibited a higher $N_2/NF_3$ selectivity (> 14) with a slightly lower $N_2$ permeance (4.5 GPU), as compared to the commercial PSf counterparts. This feature provides a good potential as a membrane structure to separate $N_2/NF_3$. 반도체 및 디스플레이 공정에서 배출되는 $N_2/NF_3$ 혼합 가스 분리를 위한 폴리썰폰 중공사막 제조 연구를 수행하였다. 먼저 non-solvent induced phase separation (NIPS)와 vapor induced phase separation (VIPS) 혼합 공정을 이용하여 기체투과성이 높은 고분자 중공사막을 제조하였다. 제조된 중공사막 표면에 PDMS(polydimethylsiloxiane)와 Teflon AF1600(R) 고분자 소재를 이용하여 얇은 박막을 추가적으로 코팅하는 방법으로 기체 분리막을 완성하였다. 제조된 분리막은 코팅된 고분자 소재의 기체 분리 특성에 따라 상이한 $N_2/NF_3$ 분리 성능을 보여주었다. 특히 Teflon AF1600(R) 이 코팅된 중공사막의 경우 $N_2/NF_3$ 분리 성능(> 14)을 보여주었고, $N_2$ 투과도는 4.5 GPU를 나타내었다. 상용 폴리썰폰 막과 비교해 볼 때, 투과도는 약간 감소하였지만 기체 선택도는 크게 증가하였다. 이런 특징은 $N_2/NF_3$를 분리하는 분리막 구조로써 큰 가능성을 지니는 것으로 판단된다.

양성전해질 고정막의 제조 및 그것의 금속이온 흡착 특성

최혁준,박상진,김민 한국막학회 2010 멤브레인 Vol.20 No.2

본 연구는 양성전해질막의 금속이온 특성을 조사하기 위하여 Taurine (TAU)막을 제조하였다. 제조방법으로는 방사선조사법에 의한 Glycidyl methacrylate (GMA)의 중공사막 표면위에 고정시키고, 이후 Taurine의 염기성 부분인 -NH2기(amine fuction)와 GMA의 glycididyl의 개환 반응을 통하여 안정된 막을 형성하도록 하였다. 한편 TAU막과 비교를 위해 GMA가 고정된 중공사 막에 Sodium sulfite로 화학적 결합을 형성 SS막을 제조하였다. 이렇게 제조된 TAU막의 타우린 밀도가 높아져도 투과유속은 0.9 m/h로 변화 없으나, SS막은 술폰산기의 밀도가 높아짐에 따라 투과유속이 급격히 감소하는 것을 나타내었다. 타우린 밀도가 0.8 mmol/g인 막을 사용한 결과 금속이온의 량은 Cu > Cd > Mg > Sb > Pb의 순으로 나타내었다. 전반적으로 타우린막은 전화율과 밀도의 증가에 따라 많은 양의 금속이온 흡착과 높은 투과유속을 나타내었다. This paper presents the synthesis of ampholyte immobilized hollow-fiber membranes and adsorption characteristic of metallic ions. This is prepared by radiation induced grafting polymerization of an epoxy group containing Glycidyl methacrylate (GMA) onto an existing polyethylene porous hollow-fiber membrane. Ampholyte ion-exchanged alkalic group, -NH2 (amine function) of Taurine (TAU) is reacted with glycidyl of GMA for the synthesis of stable membrane. However, Sodium sulfite (SS) membrane is also prepared by making chemical bonds with GMA of porous hollow-fiber membrane for the comparison of adsorption characteristic of metallic ions. These are called as TAU and SS membranes, respectively. It is shown that TAU membrane shows a steady flux, 0.9 m/h regardless of the density of TAU, while the flux of SS membrane decreases rapidly as the density of SO3H group increases. SS membrane showed a negligible flux. TAU membrane with the density 0.8 mmol/g shows the amount of metallic ions adsorbed in the following order, Cu > Cd > Mg > Sb > Pb. In general, TAU membrane with high density and reaction time showed the high amount of metallic ions adsorbed and flux.