• 제목/요약/키워드: Nitrogen permeation

검색결과 92건 처리시간 0.026초

졸-겔법에 의한 나노기공성 세라믹 막의 제조 및 기체투과 특성 (Preparation of Nanoporous Ceramic Membranes by Sol-gel Method and Characterization of Gas Permeation)

  • 이용택;최가영;한혁희
    • 멤브레인
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    • 제18권2호
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    • pp.176-184
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    • 2008
  • 본 연구에서 졸-겔 방법에 의하여 나노 기공을 가지는 세라믹막을 제조하여 단일 조성의 헬륨과 질소를 가지고 기체투과 실험을 수행하였다. 기공 크기 $0.1{\mu}m$, 기공율 32%의 평막형 ${\alpha}-Al_2O_3$ 지지체를 제조하였으며, 지지체를 담지하여 코팅하는 방법으로 4nm의 기공 크기를 가지는 ${\gamma}-Al_2O_3$ 중간층을 제조하였다. 실리카 졸은 TEOS의 산 촉매 가수분해와 축중합반응을 통하여 합성하였다. 막은 딥코팅과 소결과정을 거쳐 제조되었다. 졸-겔 법에 의해 합성된 세라믹 막을 통한 헬륨, 질소 투과 실험은 기체의 투과 특성을 파악하기 위하여 시행하였다. 질소에 대한 헬륨의 선택도는 $100{\sim}160$ 정도였으며 헬륨의 투과도는 $303{\sim}363K$의 온도 범위에서 $10^{-7}mol/m^2{\cdot}s{\cdot}Pa$ 정도였다.

ABS 복합 필름의 공기 및 수증기 투과 특성 (Permeation Characteristics of Air and Water Vapor through ABS/filler Hybrid Films)

  • 홍성욱;고영덕
    • 멤브레인
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    • 제18권3호
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    • pp.256-259
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    • 2008
  • 본 연구에서는 poly(acrylonitrile-butadiene-styrene) (ABS)에 carbon graphite와 zeolite 4A를 첨가하여 복합 필름을 제조하고 공기와 수증기 투과 특성을 살펴보았다. 복합 필름의 경우 모든 경우에서 순수한 ABS에 비해서 산소와 질소의 투과도가 감소하였으며, 산소의 투과도 감소가 질소의 투과도 감소보다 약간 큰 관계로 산소/질소 선택도도 조금 감소하였다. 또한, 수증기 투과도도 순수한 ABS에 비해서 약 1/2로 감소하였다. 이러한 투과도의 감소는 ABS에 filler를 첨가함으로 인하여 물질 확산 경로의 tortuosity가 증가했기 때문인 것으로 생각된다.

기체분리용 세라믹 복합분리막의 개발: III. 기체투과 모델에 의한 막의 특성 규명 (Development of Ceramic Composite Membranes for Gas Separation: III. Examination of Membrane Characteristics by the Gas Permeation Model)

  • 현상훈;윤성필;강범석
    • 한국세라믹학회지
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    • 제29권11호
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    • pp.905-911
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    • 1992
  • Model equations for the gas permeation through a ceramic composite membrane were derived for examining the existence of crack, the reproducibility, and the microstructural properties of composite membranes. From the results of analyzing the nitrogen permeability data through alumina-tube supported TiO2 and SiO2 composite membranes, the extent of cracking, and the formation and structure of membrane top-layers were modelled. It was proved that the crack-free and reproducible composite membranes could be easily prepared only by the pore-filled coating within pores of the support in the sol-gel coating process.

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THE PREPARTION AND CHAEATERIZATION OF ALUMINA UF MEMBRANE BY SOL-GEL PROCESS

  • Choi, Y. H.;Paik, J. S.;Kim, H. C.;Lee, S. B.;Oh-kim, E. O.
    • 한국막학회:학술대회논문집
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    • 한국막학회 1991년도 추계 총회 및 학술발표회
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    • pp.29-33
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    • 1991
  • Alumina UF membranes were prepared by sol-gel process and their gas permeabilities were characterized. Alumina MF membrane with average pore diameter about 0.12$\mu$m and tubular shape was used as a support. Gas permeation measurements of helium and nitrogen gas exhibited the permeabilities of 1.58 $\times$ 10E-6 and $0.63 \times 10E-6 cc\cdot cm(STP)/cm^2\cdot sec \cdot cmHg$, respectively. The permeability ratio was 2.5. This means the gas permeation is fully governed by knudsen diffusion mechanism.

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Isothermal Heat Treatment of AISI 430 Ferritic Stainless Steel after High Temperature Gas Nitriding

  • Park, Sang-Jun;Kim, Jung-Min;Kang, Hee-Jae;Kang, Chang-Yong;Kim, Yung-Hee;Sung, Jang-Hyun
    • 열처리공학회지
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    • 제25권3호
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    • pp.115-120
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    • 2012
  • It has been known that the ferritic stainless steel can be changed to martensitic stainless steel when nitrogen is added. However the high hardness of martensitic stainless steel prevents the plastic deformation. In this study, instead of martensite, the surface microstructure was changed into nitrogen pearlite to increase the plastic deformation easily by isothermal heat treatment after high temperature gas nitriding (HTGN) the AISI 430 ferritic stainless steel. The isothermal treatment was carried out at $780^{\circ}C$ for 4, 6, and 10 hrs, respectively, after HTGN treatment at $1100^{\circ}C$ for 10 hrs. The surface layer of isothermal-treated steel appeared nitrogen pearlite composed with fine chromium nitride and ferrite. Hence, the interior region that was not affected by nitrogen permeation exhibited ferrite phase. When quenching the isothermal treated steel at 1100oC, martensitic phase formed at the surface layer. The hardness of surface layer of isothermal-treated steel and quenched steel measured the value of 150~240 Hv and 630 Hv, respectively.

투과특성의 on-line 측정을 위한 투과장치 (Permeation Apparatus for on-line Measurement of the Permeation Characteristics through Dense Polymeric Membranes)

  • 염충균;김범식;김철웅;김광주;이정민
    • 멤브레인
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    • 제8권2호
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    • pp.86-93
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    • 1998
  • 비다공성막을 통한 투과성분의 투과속도와 투과 조성을 on-line방식으로 측정할수 있는 장치를 개발하였다. 가교폴리비닐알콜막을 통한 물의 투과증발실험을 행하여 이 장치의 효용성을 확인하였다. 투과증발실험에서 투과가 정상상태에 도달하는데 15분미만의 시간이 걸렸으며 측정을 20분이내에 마칠 수가 있었다. 또한 측정된 투과속도 정확성과 신뢰도를 확인하기 위해서 종래의 방법대로 액체질소에 의해 투과물을 일정시간 응축시켜 투과속도를 동시에 측정하여 이를 장치의 record에 표시된 투과속도와 비교한 결과 그 오차가 $\pm$2% 이내로 일치하였다. 측정된 시간에 따른 투과속도 곡선으로 부터 3가지 종류의 확산계수 $D_{slope}, D_{1/2}, D_t$를 구하였고 이들이 문헌치와 비교한 결과 비교적 일치함을 보였다. 또한 on-line 방식으로 모든 측정이 이루어지므로 종래 방법, 즉 투과물 응축, 가열, 무게측정과정 등에서 발생할 수 있는 실험오차를 줄일수 있기 때문에 정확한 투과특성을 얻을 수가 있다. 본 연구에서 개발한 투과 장치를 사용하여 액체상태의 feed 투과를 효과적으로 분석할 수 있음을 확인하였다.

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Separation of Hydrogen-Nitrogen Gas Mixture by PTMSP-Silica-PEI Composite Membranes

  • Lee, Hyun-Kyung;Kang, Tae-Beom
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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    • pp.144-147
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    • 2004
  • Organosilicon polymers have long paid attention as functional polymers [1,2]. Among others, poly- (1-trimethylsilyl-1-propyne) [PTMSP] is a polymer, which forms a gas separating membrane with extraordinary high gas permeability. In particular, composite membranes that constituted two different matrices (inorganic and organic) have been recently developed in order to improve the permeation characteristics.(omitted)

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13%Cr-0.17%C 스테인리스강의 고온 가스질화에 미치는 Al 함량 변화의 영향 (Effect of Al Content Variation on High Temperature Gas Nitriding in 13%Cr-0.16%C Stainless Steel)

  • 박범태;김정민;강희재;공정현;강창룡;성장현
    • 열처리공학회지
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    • 제24권6호
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    • pp.318-326
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    • 2011
  • This study has been performed to investigate the effect of Al addition on High Temperature Gas Nitriding (HTGN) in 13%Cr-0.16%C stainless steel with different Al contents of 0.54%, 1.76% and 2.36%, respectively. HTGN treatment was carried out at $1100^{\circ}C$ for 1 hr, 5 hrs and 10 hrs. Nitrogen-permeated surface layers showed round type carbides of $Cr_{23}C_6$ and needle type nitrides of AlN in the matrix of martensite, representing 600~700 Hv. And the thickness of the surface layer increased with increasing Al content and HTGN treatment time. The inner region that was not permeated nitrogen showed chromium carbides in the mixed phase of martensite and ferrite for the 0.53% Al alloyed steel, however chromium carbides in the matrix of ferrite single phase were shown for the steels with the addition of 1.76%Al and 2.36%Al, representing the hardness of ~200 Hv. During nitrogen permeation from surface to the interior, substitutional elements of Cr, Al and Si moved toward the surface and interstitial element of carbon also moved from interior to the surface. This movement of alloying elements leads high concentration of these elements at the outmost surface, subsequently the lowest peak of substitutional elements were shown in the vicinity of near surface. After showing the lowest peak, the high concentration region of Al and C were formed due to the continuous movement of Al toward the surface. The long discontinuous precipitates of $Cr_{23}C_6$ and AlN were formed along the outmost surface owing to the high concentration of these alloying elements.

미세다공성 세라믹 막에서의 가공응축기구에 의한 휘발성 유기화합물의 분리 (Pore Condensation-Based Separation of VOCs by a Microporous Ceramic Membrane)

  • Cha, Jun-Seok
    • Journal of Korean Society for Atmospheric Environment
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    • 제12권E호
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    • pp.19-28
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    • 1996
  • A pore concensation-based separation technique was studied experimentally using toluene and xylene in a nitrogen stream. The removal rate of toluene and xylene on a microporous ceramic membrane was enhanced by increasing the partial pressure difference across the membrane, but the selectivity was reduced with increasing flux of nitrogen. This was found both in vacuum and pressure modes of operation. The experimental results from this study suggest that the pores mear the inlet portion of the module were filled with the organic solvent while the pores near the exit section of the module were slightly opened as the solvent concentration was depleted along the module. In the case of xylene, the rate of N$_{2}$ permeation was reduced considerably relative to toluene, resulting in a much higher separation gactor. Condensibility of xylene appeared to be higher than that of toluene, the potential for pore condensation-based separation of xylene was also found to be higher than that for toluene.

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The flow of $CO_{2}$ and $N_{2}$ gases through Asymmetric polytherimide Membrane

  • Park, You-In;Lee, Kew-Ho
    • 한국막학회:학술대회논문집
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    • 한국막학회 1995년도 제3회 심포지움 (분리막 연구의 최신동향)
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    • pp.73-85
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    • 1995
  • The asymmetric hollow fiber membranes were prepared by the wet spining of polyetherimide dope solution and the effect of hollow fiber structures on the permeation characteristics of carbon dioxide and nitrogen gases through these membrane were investigated. As the concentration of the $\gamma$-butyrolactone (GBL) in dope solution, acting as a swelling agent was increased, the structure of hollow fiber was changed from the finger to sponge type. The permeabilities of gases (CO$_{2}$, N$_{2}$) through these membrane were measured over the wide range of pressure under different temperature. The effect of water vapor on the permeabilities of gases was also investigated. The measured permeabilities showed the different characteristics depending on the structure of membranes. It was found that the flow through the pores were dominant over the polymers matrix. Blocking effect by water vapor in the pores of skin layer greatly improved the ideal separation factor of carbon dioxide/nitrogen.

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