• Membrane and Water Treatment
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• 제10권2호
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• pp.127-137
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• 2019

The D2EHPA/TBP co-extractants immobilized PolyHIPE membrane can be used for the selective separation of Mn (II) from Co (II). By solvent-nonsolvent method, D2EHPA/TBP co-extractants can be effectively immobilized into PolyHIPE membrane. The pore structure of PolyHIPE membrane and the presence of TBP enhance the stability of immobilized co-extractants. The optimal operating conditions for the separation of Mn (II) and Co (II) are feeding phase at pH 5.5, sulfuric acid concentration in the stripping phase of about 50 g/L and stirring speed at 400 rpm. The D2EHPA/TBP co-extractants ratio of 5:1 shows synergetic effect on Mn/Co separation factor about 22.74. The removal rate and recovery rate of Mn (II) is about 98.4 and 97.1%, respectively, while for Co (II) the transport efficiency is insignificant. The kinetic study of Mn (II) transport shows that high initial flux, $J_f^o=80.1({\mu}mol/m^2s)$, and maxima stripping flux, $J_s^{max}=20.8({\mu}mol/m^2s)$, can be achieved with D2EHPA/TBP co-extractants immobilized PolyHIPE membrane. The stability and reusability study shows that the membrane can maintain a long term performance with high efficiency. High purity of Co (II) and Mn (II) can be recovered from the feeding phase and stripping phase, respectively.

• 한국세라믹학회지
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• 제34권7호
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• pp.747-757
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• 1997

ZSM-5 zeolite composite membranes have been synthesized from a silica sol solution containing TPABr as an organic template by the dip-coating and the pressurized-coating hydrothermal treatment techniques. The CO2 separation efficiency of synthesized composite membranes was also investigated. The permeation mechanism of CO2 through ZSM-5 membranses was the surface diffusion, and that of N2, O2, and He gases was Knudsen diffusion or activated diffusion depending on the synthetic method of membranes and the measurement temperature. The CO2/N2 separation factor of the membrane prepared by the dip-coating hydrothermal treatment was 2.5 at about 12$0^{\circ}C$, while the ZSM-5 composite membrane synthesized by the pressurized-coating hydrothermal treatment technique showed the CO2/N2 separation factor of 9.0 at room temperature higher than that ever reported in the literature.

• 멤브레인
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• 제22권2호
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• pp.142-154
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• 2012

DME 제조공정에서 발생하는 혼합가스 중 $CO_2$를 제거하기 위해서 $H_2$ 투과도보다 $CO_2$투과도가 우수한 고무상 고분자를 분리소재로 선정하여 복합막을 제조하고 $CO_2/H_2$의 분리성능을 검증하여 보았다. 지지체 중공사막 소재로 PEI를 이용하여 지지체 중공사막을 제조하였으며, 제조된 지지체 중공사막의 기체투과도를 각 가스별로 측정하여 PDMS의 경우는 $CO_2$ 투과도 300 GPU 이상, $CO_2/H_2$의 선택도가 4.3 이상, PEBAX를 사용한 경우 $CO_2$ 투과도 120 GPU 이상 $CO_2/H_2$의 선택도가 5 이상인 복합 중공사를 제조하였다.

• 대한환경공학회지
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• 제36권2호
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• pp.147-152
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• 2014

본 연구에서는 폴리설폰 중공사막을 이용하여 화석연료 연소에서 배출되는 온실가스 중 $CO_2$의 회수에 관한 연구를 실시하였다. 고농도의 $CO_2$를 회수하기 위한 막분리 공정에 대한 선행연구이다. 혼합가스 분리거동 관찰을 위하여 이산화탄소가 10% 함유된 배기가스를 사용하였다. 압력, 온도, 주입가스 조성, 다단 막 변화를 주어 스테이지 컷에 따른 분리 성능을 조사하였다. 압력과 온도가 증가 할수록 투과측에 $CO_2$ 농도와 회수율이 증가하였다. 주입 가스 조성 변화 시 $CO_2$의 함량이 높을 경우 회수율 및 분리 효율이 높아졌다. 3단 분리막 시스템을 이용시 $CO_2$ 농도 95% 이상, 회수율 90% 이상 보였으며 1단 분리막 보다 분리율이 향상되었다.

• Korean Membrane Journal
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• 제8권1호
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• pp.21-30
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• 2006

A faujasite NaY zeolite membrane was prepared on a tubular ${\alpha}-Al_2O_3$ support by the secondary growth process, and effects of permeation test conditions on the $CO_2/N_2$ separation were investigated. A NaY zeolite membrane with good $CO_2/N_2$ separation was successfully synthesized by using the hydrothermal solution ($Al_2O_3:SiO_2:Na_2O:H_2O$ = 1:6:14:840 in a molar base): at a permeation temperature of $30^{\circ}C$, its $CO_2$ permeance and $CO_2/N_2$ separation factor were $2.5{\times}10^{-7}mol/m^2secPa$ and 34, respectively. The $CO_2$ and $N_2$ permeations were highly dependent on permeation test conditions (feed composition, feeding rate, feed pressure, He sweeping rate and permeation temperature). The results indicated that (i) $CO_2$ and $N_2$ permeations through NaY zeolite membrane are governed by surface and micropore diffusions, respectively, (ii) the preparation of NaY zeolite membrane with a large permeating area is one of the most difficult hurdles for its real applications, and (iii) the retardation of $N_2$ permeation is an effective key to improve $CO_2/N_2$ separation factor in NaY zeolite membrane.

• 한국환경과학회지
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• 제8권2호
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• pp.263-269
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• 1999

For effective $CO_2$ separation using pore size controlled membrane, silica was deposited in the mesopores of a $\gamma$-alumina film by chemical vapor deposition of tetraethoxysilane (TEOS) and phenyl-substituted ethoxysilanes at 773-873K. The membranes prepared with phenyl-substituted ethoxysilanes were calcined to remove the phenyl group and control the pore size. The gas permaselectivity of prepared membranes was evaluated by using $H_2$, $CO_2$ $N_2$, $CH_2$ and $C_3H_8$ single component and a mixture of $CO_2$ and $N_2$. The membranes produced using TEOS contained micropores having permselectivity only to hydrogen, but the phenyl-subsitituted ethoxysilane derived membranes possessed micorpores which are recognizable molecules of $CO_2$, $N_2$ and $CH_4$. In the diphenyl-diethoxysilane-derived membrane, the $CO_2$ permeance and selectivity of $CO_2$/$CH_4$ were $10^{-6} m^3(STP) \cdot m^{-2} \cdot s^{-1} \cdot kPa^{-1}$ and 11, respectively. Therefore, the use of phenyl-substituted ethoxysilane was effective in controlling micropore size for $CO_2$ separation.

• 멤브레인
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• 제27권3호
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• pp.226-231
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• 2017

이산화탄소 분리를 위해 이온성 액체/금속 산화물 복합막이 제조되었으며, 이온성 액체로서 1-butyl-3-methylimidazolium tetrafluoroborate ($BMIM^+BF_4{^-}$)와 금속산화물로서 $Al_2O_3$가 사용되었다. 13 nm의 $Al_2O_3$가 이온성 액체 $BMIM^+BF_4{^-}$에 도입되었을 때, 복합체 분리막의 성능은 $CO_2/N_2$ 선택도 30.5과 $CO_2$ 투과도 45.7 GPU로 관찰되었다. neat $BMIM^+BF_4{^-}$ 분리막의 성능($CO_2/N_2$ 선택도 5와 $CO_2$ 투과도 17 GPU)에 비해서 성능이 증가한 이유는 $Al_2O_3$의 옥사이드 층과 이온성 액체 내 자유로운 이온농도의 상승으로 인해 $CO_2$ 용해도가 상승한 것으로 확인되었다. 특히 $Al_2O_3$ 나노입자는 질소 기체에 대해서 장애물로서 작용함으로써 질소기체의 투과도가 감소하여 결과적으로 이산화탄소 분리 성능은 급격히 증가하였다.

• 멤브레인
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• 제10권3호
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• pp.130-138
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• 2000

건/습식 상전환법을 이용하여 비대칭 polyethersulfone (PES) 기체분리막을 제조하였으며, $CO_2$, $N_2$등의 기체에 대한 투과특성을 조사하였다. 분리막 제조에 있어서 주요 변수인 캐스팅 용액과 증발시간 등이 분리막의 구조에 미치는 영향을 파악하고 투과특성을 조사하여 최적의 제조조건을 확립하였다. 또한 제조된 분리막의 표피층에 존재하는 pin-hole과 같은 결점을 보완하기 위하여 실리콘 수지를 코팅하여 그 투과특성의 변화를 조사하였다. 실리콘 수지 코팅이 결점을 보완하는데 효과적임을 확인하였다. 본 연구에서 분리막 제조에 주로 사용한 캐스팅 용액은 PES, 14-methyl-2-pyrrolidone, 아세톤, 에탄올로 구성되었으며, 응고제로는 증류수를 사용하였다. 캐스팅 용액 중의 PES 함량이 높아질수록, 휘발성 유기용매의 비율이 높아질수록, 증발시간이 길수록, 에탄을 첨가제의 농도가 낮을수록 $CO_2$/$N_2$의 선택도는 높아지고 투과도는 낮아지는 결과를 보였다. 최적의 분리막 제조조건 하에서 얻어진 분리막의 분리성능은 $CO_2$/$N_2$의 선택도가 61이고 $CO_2$의 투과도는 21 GPU인 우수한 결과를 보였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.227-234
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• 2004

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion(CLC) may yield great advantages of savings of energy to $CO_2$ separation and suppressing the effect on environment. In chemical-looping combustor, fuel is oxidized by metal oxide medium (oxygen carrier particle) in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. The purpose of this study is to demonstrate inherent $CO_2$ separation and no NOx emission and to confirm high $CO_2$ selectivity, no side reaction (i.e., carbon deposition, hydrogen generation) by continuous reduction and oxidation experiment in a 50kWtb chemical-looping combustor. NiO/bentonite particle was used as a bed material and $CH_4$ and air were used as reacting gases for reduction and oxidation respectively.

• 한국재료학회지
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• 제28권7호
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• pp.417-422
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• 2018

The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for $CO_2$ reduction application. The textural properties of these microporous materials are investigated, and their $CO_2$ storage capacity and separation performance are evaluated. Owing to the combined effects of $CO_2-Amino$ interaction and its flexibility, a $CO_2$ uptake of $2.5mmol\;g^{-1}$ is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, $CH_4$ uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for $CO_2/CH_4$ separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher $CO_2$ uptake of $4.7mmol\;g^{-1}$ is also observed at 20 bar 298 K. Furthermore, the $CH_4$ storage capacity is $2.9mmol\;g^{-1}$ at 298 K and 20 bar. To evaluate the $CO_2$ separation performance, the selectivity based on ideal adsorption solution theory for $CO_2/CH_4$ binary mixtures on the presented porous materials is investigated.