• Title, Summary, Keyword: oxygen permeation

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Electrochemical Properties of a Zirconia Membrane with a Lanthanum Manganate-Zirconia Composite Electrode and its Oxygen Permeation Characteristics by Applied Currents

  • Park, Ji Young;Jung, Noh Hyun;Jung, Doh Won;Ahn, Sung-Jin;Park, Hee Jung
    • Journal of the Korean Ceramic Society
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    • v.56 no.2
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    • pp.197-204
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    • 2019
  • An electrochemical oxygen permeating membrane (OPM) is fabricated using Zr0.895Sc0.095Ce0.005Gd0.005O2-δ (ScCeGdZ) as the solid electrolyte and aLa0.7Sr0.3MnO3-bScCeGdZ composite (LZab, electrode) as the electrode. The crystal phase of the electrode and the microstructure of the membrane is investigated with X-ray diffraction and scanning electron microscopy. The electrochemical resistance of the membrane is examined using 2-p ac impedance spectroscopy, and LZ55 shows the lowest electrode resistance among LZ82, LZ55 and LZ37. The oxygen permeation is studied with an oxygen permeation cell with a zirconia oxygen sensor. The oxygen flux of the OPM with LZ55 is nearly consistent with the theoretical value calculated from Faraday's Law below a critical current. However, it becomes saturated above the critical current due to the limit of the oxygen ionic conduction of the OPM. The OPM with LZ55 has a very high oxygen permeation flux of ~ 3.5 × 10-6 mol/㎠s in I = 1.4 A/㎠.

Dense Ceramic-metal Composite Inorganic Membranes for Oxygen Separation (산소 분리를 위한 무공성 세라믹- 금속 복합 무기막)

  • 김진수
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.35-41
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    • 2002
  • Dense oxygen ionic conducting materials can be used for oxygen separation membranes at high temperatures. However, they show relatively low permeation flux because of their large resistances. To reduce resistances and improve the oxygen permeation flux, thin dense yttria-stabilized-zirconia (YSZ)/Pd composite dual-phase membranes were fabricated by a new approach that combines the reservoir method and chemical vapor deposition (CVD). A thin porous YSZ layer was coated on a porous alumina support by dip-coating the YSZ suspension. A continuous Pd phase was formed inside pores of the YSZ layer by the reservoir method. The residual pores of the YSZ/Pd layer were plugged with yttria/zirconia by CVD to ensure the gas tightness of the membranes. The oxygen permeation fluxes through these composite membrane were 2.0$\times$10$^{-8}$ mol/cm$^2$.s and 4.8$\times$10$^{-8}$ mol/cm$^2$.s at 105$0^{\circ}C$ when air and oxygen were used as the permeate gases, respectively. These oxygen permeation values are about 1 order of magnitude higher than those of pure YSZ membranes prepared under similar conditions.

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Further improvements in oxygen permeation properties of La0.6Sr0.4Ti0.3Fe0.7O3-δ coated Ba0.5Sr0.5Co0.8Fe0.2O3-δ hollow fiber membrane

  • Park, Se Hyung;Magnone, Edoardo;Park, Jung Hoon
    • Journal of Industrial and Engineering Chemistry
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    • v.56
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    • pp.350-354
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    • 2017
  • Oxygen-permeable $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ (BSCF) hollow fiber membranes was prepared by a phase inversion spinning process. In the second stage, $La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$ (LSTF) was coated on the surface of the prepared BSCF hollow fiber membranes by dip coating method in an attempt to improve not only the oxygen permeation performance but also the long-term chemical stability. The oxygen permeation fluxes were measured in the temperature range of $850-1000^{\circ}C$ in air. The oxygen permeation flux reached to $9.18mL/min/cm^2$ at $1000^{\circ}C$. In addition, long-term operation test results indicated that the oxygen permeation fluxes remained consistently during the 240 h operation. With the dual aims of reviewing existing work in the topic and understanding the effects of membrane morphology and thickness on the performance of BSCF membrane, the oxygen permeation property of LSTF-coated BSCF hollow fiber membrane with engineered morphology was compared directly with its corresponding uncoated case and then with other configuration types, such as BSCF disk-shaped and tubular BSCF membranes.

Oxygen Permeation Properties of $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ Mixed-conducting Membrane (혼합전도성 $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ 분리막의 산소투과 특성)

  • Lim, Kyoung-Tae;Cho, Tong-Lae;Lee, Kee-Sung;Woo, Sang-Kuk;Park, Kee-Bae;Kim, Jong-Won
    • Journal of the Korean Ceramic Society
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    • v.38 no.9
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    • pp.787-793
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    • 2001
  • $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ membranes were fabricated by solid-state reaction. We investigated sintering behavior and oxygen permeation flux as a function of time-on-stream, temperature and upstream oxygen partial pressure. The oxygen was permeated at temperatures form 750$^{\circ}$C to 950$^{\circ}$C by mixed conducting through oxygen vacancy diffusion in the dense membrane. The oxygen permeation flux through the membrane were about 0.1ml/$cm^3{\cdot}$min at 850$^{\circ}$C. A constant time was required for reaching stable oxygen flux, and oxygen partial pressure affected the oxygen permeation fluxes.

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Preparation of Cellulose Acetate Containing Silver Nitrate as Oxygen Carrier (질산은을 산소 캐리어로 하는 CA막의 제조)

  • Ahn, Pil-Seong;Lee, Woo-Tai
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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    • pp.83-90
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    • 1999
  • A cellulose acetate membrane containing silver nitrate was prepared by gelatinizing in water at $2^{\circ}C$ after evaporating solvent from the casting solution on a glass plate. Permeation experiments for oxygen and nitrogen were conducted in the ranges of temperature, $5-40^{\circ}C$ and pressure difference, $1-5kg/cm^2$ in order to investigate the effects of temperature and pressure difference on permeation characteristics of the membrane. When the evaporation time was increased, the permeability of oxygen decreased but the separation factor of oxygen against nitrogen increased since a more dense layer was formed on the membrane surface. When the silver nitrate was added, the permeation flux was doubled and the separation factor was improved from 3.0 to 3.3. This implies that silver nitrate acts as an oxygen carrier in the membrane.

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The Effect of Water Vapor on th ePermeation of Oxygen/Nitrogen through Polysulfone Hollow -Fiber Membrane (폴리설폰 중공사막에 대한 산소/질소의 투과도에 미치는 수분의 영향)

  • 김진천;김종수;조정식;최기석;이광래
    • Membrane Journal
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    • v.9 no.1
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    • pp.43-50
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    • 1999
  • The effects of water vapor on the permeation rates of oxygen and nitrogen through poly sulfone hollow-fiber membrane were investigated. The permeation rates of both 02 and $O_2$ were decreased significantly owing to the presence of water vapor. The permeation rate of oxygen with 100% relative humidity was reduced by as much as 20%, while the permeation rate of nitrogen decreased by 14% at 30 "C and 3kgf/$cm^2$ of upstream pressure. The permeation rates of $O_2$ were declined monotonously with running time and arrived at steady state values by the presence of water vapor. However, those of $N_2$ increased tentatively and then decreased to the steady state.tate.

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Surface reactive micro/nano particles on inorganic oxygen separation membrane

  • Lee, Kee-Sung;Shin, Tae-Ho;Lee, Shiwoo;Woo, Sang-Kuk;Yang, Jae-Kyo;Choa, Yong-Ho
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.94-97
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    • 2004
  • Micro/nano-sized L $a_{0.6}$S $r_{0.4}$Co $O_{3-}$$\delta$/ particles are considered to improve oxygen permeability in highly selective inorganic oxygen separation membrane. A L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membrane with perovskite structure is fabricated by a conventional solid-state reaction. As the oxygen permeation flux of the L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membrane was lower than commercial gas separation membranes, we coated the L $a_{0.6}$S $r_{0.4}$Co $O_{3-}$$\delta$/ particles to enhance the oxygen permeation flux. It has been demonstrated that the effective area of reactive free surface is an important factor in determining the effectiveness of the introduction of coating layer for oxygen permeation. The introduction of micro/nano L $a_{0.6}$S $r_{0.4}$Co $O_{3-}$$\delta$/ particles was very effective for increasing oxygen flux, as the flux was as much as 2 to 6 times higher than that of an uncoated L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membrane.\delta$/ membrane.>/ membrane.brane.

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Hollow Fiber Dialysis Culture of E. coli (대장균의 실관투석배양)

  • 김인호;윤태호
    • KSBB Journal
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    • v.9 no.5
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    • pp.492-498
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    • 1994
  • A hollow fiber device was utilized to perform a dialysis culture for E. coli. Acetic acid inhibition on the growth of E. coli was relieved by dialyzing the acid from broth into a dialysate reservoir. The rate of acetic acid formation was very sensitive to the concentration of glucose and dissolved oxygen. Therefore it was found that the glucose permeation rate should be balanced with the oxygen supply rate. Specific growth rate of E. coli was determined by the glucose permeation rate through membrane. Under a low permeation rate, acetic acid formation was depressed in accordance with high dissolved oxygen concentration as well as low glucose concentration.

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Characteristics of Oxygen Permeation on $YBaCo_2O_{5+{\delta}}$ Ceramic Membrane ($YBaCo_2O_{5+{\delta}}$ 세라믹 분리막의 산소투과 특성)

  • Pyo, Dae-Woong;Kim, Jong-Pyo;Park, Jung-Hoon
    • Membrane Journal
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    • v.22 no.2
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    • pp.113-119
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    • 2012
  • $YBaCo_2O_{5+{\delta}}$ oxide was synthesized by solid state reaction and a typical dense membrane has been prepared using as-prepared powder by unilateral pressing and sintering at $1,180^{\circ}C$. The $YBaCo_2O_{5+{\delta}}$ membraneswas analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD analysis showed the double layered perovskite structure was observed over $1,150^{\circ}C$ without impurities. Oxygen permeation was measured in the temperature range from 750 to $950^{\circ}C$ according to oxygen partial pressure difference between feed and permeation side. The oxygen permeation flux increased with increasing temperature and oxygen partial pressure and the maximum oxygen flux of $YBaCo_2O_{5+{\delta}}$ membrane with 1.0 mm thickness was about 0.15 mL/$cm^2{\cdot}min$ at $950^{\circ}C$ and $PO_2$ = 0.42 atm. The activation energy for oxygen permeation decreased with decreasing oxygen partial pressure to be 76.0 kJ/mol at the condition of $PO_2$ = 0.21 atm.

The Role of Metal Catalyst on Water Permeation and Stability of BaCe0.8Y0.2O3-δ

  • Al, S.;Zhang, G.
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.212-219
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    • 2018
  • Perovskite type ceramic membranes which exhibit dual ion conduction (proton and oxygen ion conduction) can permeate water and can aid solving operational problems such as temperature gradient and carbon deposition associated with a working solid oxide fuel cell. From this point of view, it is crucial to reveal water transport mechanism and especially the nature of the surface sites that is necessary for water incorporation and evolution. $BaCe_{0.8}Y_{0.2}O_{3-{\alpha}}$ (BCY20) was used as a model proton and oxygen ion conducting membrane in this work. Four different catalytically modified membrane configurations were used for the investigations and water flux was measured as a function of temperature. In addition, CO was introduced to the permeate side in order to test the stability of membrane against water and $CO/CO_2$ and post operation analysis of used membranes were carried out. The results revealed that water incorporation occurs on any exposed electrolyte surface. However, the magnitude of water permeation changes depending on which membrane surface is catalytically modified. The platinum increases the water flux on the feed side whilst it decreases the flux on the permeate side. Water flux measurements suggest that platinum can block water permeation on the permeate side by reducing the access to the lattice oxygen in the surface layer.