• Title/Summary/Keyword: 수소 투과

Search Result 291, Processing Time 0.025 seconds

Effects of CO and $CO_2$ on Hydrogen Permeation through Pd-coated V-Ti-Ni Alloy Membranes (Pd 코팅된 V-Ti-Ni 합금 분리막을 통한 수소투과에서 CO와 $CO_2$의 영향)

  • Jeon, Sung-Il;Park, Jung-Hoon;Lee, Yong-Taek
    • Membrane Journal
    • /
    • v.21 no.3
    • /
    • pp.290-298
    • /
    • 2011
  • The influence of co-existing gases on the hydrogen permeation was studied through a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane. The hydrogen permeation characteristics of Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane have been investigated in the pressure range 1-3 bar under pure hydrogen and hydrogen mixture gas with carbon dioxide and carbon monoxide at $450^{\circ}C$. Preliminary hydrogen permeation experiments have been confirmed that hydrogen flux was $5.36mL/min/cm^2$ for a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane (thick: 0.5 mm) using pure hydrogen as the feed gas. In addition, hydrogen fluxes were 4.46, 5.20, $3.91mL /min/cm^2$ for$V_{53}Ti_{26}Ni_{21}$ alloy membrane using $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ as the feed gas respectively. Therefore, the hydrogen permeation flux decreased with decrease of hydrogen partial pressure irrespective of temperature and pressure when $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ mixture applied as feed gas respectively and permeation fluxes were satisfied with Sievert's law in different feed conditions. It was found from XRD results after permeation test that the Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane had good stability and durability for various mixtures feeding condition.

Gas permeation properties of $SiO_2$ membranes formed by sol-gel and CVD techniques (솔-젤 및 화학증착법에 의하여 제조된 실리카막의 기체 투과 특성)

  • 남석우;이희준;하홍용;홍성안
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 1996.04a
    • /
    • pp.51-52
    • /
    • 1996
  • 무기막을 기체 분리 및 분리막 반응기에 적용하려면 특정 기체에 대한 선택도 뿐만 아니라 절대 투과 속도 또한 높아야 한다. 박막 담지 무기막은 다공성 지지체를 사용하여 그위 또는 그 기공 내에 선택적 투과성을 지니는 막을 합성한 형태로서, 되도록 얇은 선택적 투과막을 지지체에 제조함으로써 투과도를 향상시킬 수 있다. 고온에서 수소에 투과성이 있는 실리카막의 경우 기공의 크기기 4nm 정도인 다공성 유리를 지지체로 하여 화학증착법으로 제조하는 연구가 많이 수행되어 왔으며 400$\circ$ 이상의 온도에서 막을 통한 수소의 투과도는 0.1 cm$^3$[STP]/min-atm-cm$^2$ 수준이었다. 본 연구에서는 실리카 담지 무기막의 수소 투과성 향상을 위하여 기공의 크기가 다공성 유리보다 큰 다공성 알루미나를 지지체로 사용하였으며, 이 지지체의 기공 내부에 솔-젤 및 화학증착법에 의하여 실리카 막을 합성하고 고온에서의 기체 투과 특성을 살펴보았다.

  • PDF

Synthesis of $H_2$-Permselective Silica Films by Chemical Vapor Deposition (화학증착(CVD)에 의한 선택적 수소 투과성 실리카막의 제조)

  • 남석우;하호용;홍성안
    • Membrane Journal
    • /
    • v.2 no.1
    • /
    • pp.21-32
    • /
    • 1992
  • Hydrogen-permselective silica membranes were synthesized within tim walls of porous Vycor tubes by chemical vapor depostion of $SiO_2$. Film deposition was carried out using $SiCl_4$ hydrolysis either in the oppm shag reactants or in the one-sided geometry. At temperatures above $600^{\circ}C$ the permeation rate of hydrogen thorough the silica films varied between 0.01 and $025cm^3(STP)/cm^2-min-atm$ depending on the reaction geometry and the $H_2 : N_2$ permeation ratio was about 1000. Permeation rates of both $H_2$ and $N_2$ increased with increasing temperature. The silica membranes produced by one-sided deposition have higher hydrogen permmeation rates than those produced by the opposing reactants geometry although the membranes formed in an opposing reactants geometry were relatively stable during the heat treatment or after exposure to ambient air. These membranes can be applied to high temperature gas separations or membrane reactors once the film deposition process is optimized to get high permeability as well as good stability.

  • PDF

Hydrogen Permeation Performance of Ni48Nb32Zr20 Alloy Membrane Coated with Pd by Sputtering (스퍼터링으로 Pd가 코팅된 Ni48Nb32Zr20 합금분리막의 수소 투과 성능)

  • Min Chang Shin;Jung Hoon Park
    • Membrane Journal
    • /
    • v.34 no.2
    • /
    • pp.140-145
    • /
    • 2024
  • In modern times, when a change in the energy paradigm is required, hydrogen is an attractive energy source. Among these hydrogen purification technologies, technology using a membrane is attracted attention as a technology that can purify high purity hydrogen at low cost. However, palladium(Pd), which is mostly used because of its excellent hydrogen separation performance, is very expensive, so a replacement material is needed. In this study, a alloy membrane was manufactured from an alloy of niobium (Nb), which has high hydrogen permeability but is weak to hydrogen embrittlement, and nickel (Ni) and zirconium (Zr), which have low hydrogen permeability but are highly durable. Hydrogen permeation characteristics were confirmed under conditions of 350~450 ℃ at 1 to 4 bar. The maximum hydrogen permeation flux was 0.69 ml/cm2/min for the Ni48Nb32Zr20 alloy membrane without Pd coating, and 13.05 ml/cm2/min for the Pd coated alloy membrane.

The Characteristics of Hydrogen Permeation through Pd-coated $Nb_{56}Ti_{23}Ni_{21}$ Alloy Membranes (Pd 코팅된 $Nb_{56}Ti_{23}Ni_{21}$ 합금 분리막의 수소투과 특성)

  • Jung, Yeong-Min;Jeon, Sung-Il;Park, Jung-Hoon
    • Membrane Journal
    • /
    • v.22 no.1
    • /
    • pp.1-7
    • /
    • 2012
  • We make a studyof the hydrogen permeability and chemical stability of $Nb_{56}Ti_{23}Ni_{21}$ metal alloy membrane. For this purpose, we produced the $Nb_{56}Ti_{23}Ni_{21}$ membrane which has 10 mm diameter and 0.5 mm thick, and experiment the hydrogen transport properties under two kinds of feed gas ($H_2$ 100%; $H_2$ 60% + $CO_2$ 40%) at $450^{\circ}C$C with variation of absolute pressure.The maximum hydrogen permeation flux was $5.58mL/min/cm^2$ in the absolute pressure 3 bar under pure hydrogen. And each case of feed gases about gas composition, the permeation fluxes were satisfied with Sievert's law, and the hydrogen permeation flux decreased with decrease of hydrogen partial pressure irrespective of temperature and pressure. After permeation test, we experiment the stability and durability of $Nb_{56}Ti_{23}Ni_{21}$ alloy membrane for carbon dioxide by XRD analysis.

Hydrogen separation of $V_{99.8}B_{0.2}$ Alloy Membrane in Water-gas shift Reaction (수성 가스 전이반응에서 $V_{99.8}B_{0.2}$ 합금 분리막의 수소분리)

  • Jeon, Sung-Il;Jung, Yeong-Min;Park, Jung-Hoon;Lee, Yong-Taek
    • Membrane Journal
    • /
    • v.22 no.1
    • /
    • pp.16-22
    • /
    • 2012
  • The influence of co-existing gases on the hydrogen permeation without sweep gas was studied through a Pd-coated $V_{99.8}B_{0.2}$ alloy membrane. Membranes have been investigated in the pressure range 1.5-8.0 bar under pure hydrogen, hydrogen-carbon dioxide and hydrogen-carbon monoxide gas mixture without sweep gas at $400^{\circ}C$. Preliminary hydrogen permeation experiments without sweep gas have been confirmed that hydrogen flux was $40.7mL/min/cm^2$ for a Pd-coated $V_{99.8}B_{0.2}$ alloy membrane (thick : 0.5 mm) using pure hydrogen as the feed gas. In addition, hydrogen flux was $21.4mL/min/cm^2$ for $V_{99.8}B_{0.2}$ alloy membrane using $H_2/CO_2$ as the feed gas. The hydrogen permeation flux decreased with decrease of hydrogen partial pressure irrespective of pressure when $H_2/CO_2$and $H_2/CO$mixture applied as feed gas respectively and permeation fluxes were satisfied with Sievert's law in different feed conditions. It was found from XRD, SEM/EDX results after permeation test that the Pd-coated $V_{99.8}B_{0.2}$ alloy membrane had good stability and durability for various mixtures feeding condition.

Synthesis of Silica/Alumina Composite Membrane Using Sol-Gel and CVD Method for Hydrogen Purification at High Temperature (Sol-gel 및 CVD법을 이용한 고온 수소 분리용 silica/alumina 복합막의 합성)

  • 서봉국;이동욱;이규호
    • Membrane Journal
    • /
    • v.11 no.3
    • /
    • pp.124-132
    • /
    • 2001
  • Silica membranes were prepared on a porous ${\alpha}$-alumina tube with pore size of 150nm by sol-gel and chemical vapor deposition(CVD) method for hydrogen separation at high temperatures. Silica and ${\gamma}$-lumina membranes formed by the sol-gel method possessed a large amount of mesopores of a Knudsen diffusion regime. In order to improve the $H_2$ selectivity, silica was deposited in the sol-gel derived silica/${\gamma}$-alumina layer by thermal decomposition of tetraethyl orthosilicate(TEOS) at $600^{\circ}C$. The CVD with forced cross flow through the porous wall of the support was very effective in plugging mesopores that were left unplugged in the membranes. The CVD modified silica/alumina composite membrane completely rejected nitrogen permeation and thus showed a high $H_2$ selectivity by molecular sieve effect. the permeation of hydrogen was explained by activated diffusion and the activation energy was 9.52kJ/mol.

  • PDF

Comparison of Hydrogen Crossover Current Density by Analysis Method of Linear Sweep Voltammetry(LSV) in Proton Exchange Membrane Fuel Cells (고분자전해질연료전지에서 선형주사전압전류측정법(LSV)의 분석방법에 따른 수소투과전류밀도 비교)

  • Oh, Sohyeong;Hwang, Byungchan;Lee, Mooseok;Lee, Donghoon;Park, Kwonpil
    • Korean Chemical Engineering Research
    • /
    • v.56 no.2
    • /
    • pp.151-155
    • /
    • 2018
  • Degree of membrane degradation in Proton Exchange Membrane Fuel Cells (PEMFC) is mainly evaluated by the hydrogen crossover current density. The hydrogen crossover current density is measured by linear sweep voltammetry (LSV), which differs from the DOE protocol and the NEDO protocol. In this study, two protocols were compared during PEMFC operation and accelerated stress test. In the LSV method by the DOE method, the scan rate change affects the hydrogen crossover current density, but the NEDO method does not affect the hydrogen crossover current density. In the course of 15,000 cycles of polymer membrane wet/dry cycle, the DOE method was sensitive to membrane degradation, but the NEDO method was less sensitive to membrane degradation than the DOE method.

Fabrication and Hydrogen Permeation Properties of $V_{99.8}B_{0.2}$ Alloy Membrane for Hydrogen Separation (수소 분리를 위한 $V_{99.8}B_{0.2}$ 분리막의 제조와 수소투과특성)

  • Jung, Yeong-Min;Jeon, Sung-Il;Park, Jung-Hoon
    • Membrane Journal
    • /
    • v.21 no.4
    • /
    • pp.345-350
    • /
    • 2011
  • No investigation has yet been accomplished to screen the boron-doped effects on vanadium based metal membranes. The synthesis, hydrogen permeation properties and chemical stability of a novel Pd-coated $V_{99.8}B_{0.2}$ alloy membrane are presented in this report. Hydrogen permeation experiments have been performed to investigate the hydrogen transport properties through the Pd-coated $V_{99.8}B_{0.2}$ alloy membrane in the absolute pressure range 1.0~3.0 bar under pure hydrogen, hydrogen-carbon dioxide gas mixture at $400^{\circ}C$. The maximum hydrogen permeation flux was $48.5mL/min/cm^2$ for a 0.5 mm thick membrane under pure hydrogen. This results offer new direction in the synthesis of novel non-Palladium-based metal membranes for hydrogen separation in water-gas shift reaction.

Vapor Permeation Separation of MTBE-Methanol Mixtures Using Cross-linked PVA Membranes (가교된 PVA 막을 이용한 MTBE/methanol 혼합물의 증기투과(Vapor Permeation)분리)

  • 김연국;임지원
    • Membrane Journal
    • /
    • v.10 no.3
    • /
    • pp.148-154
    • /
    • 2000
  • Poly(vinyl alcohol)(PVA)/sulfur-siccinic acid(SSA) membrane performances have been studied for the vapor permeation separation of methyl tort-butyl ether(MTBE)/methanol mixtures with varying operation temperatures, amount of cross-linking agents, and feed compositions. 1'here are two factors, the membrane network and the hydrogen bonding, in the swelling measurements of PVA/SSA membranes. These two factors act interdependently on the membrane swelling. The sulfuric acid group in SSA took an important role in the membrane performance. The cross-linking effect might be more dominant than the hydrogen bonding effect due to the sulfuric acid group at 7% SSA membrane. Hydrogen bonding effect was more important for 5% SSA membrane. In vapor permeation, density or concentration of methanol in vapor feed is lower than that of methanol in liquid feed, as a result, the hydrogen bonding portion between the solvent and the hydroxyl group in PVA is reduced in vapor permeation. In this case, the 7% SSA membrane shows the highest separation factor of 2187 with the flux of 4.84g/$m^2$hr for MTBE/methanol=80/20 mixtures at 3$0^{\circ}C$.

  • PDF