• 한국표면공학회지
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• 제42권5호
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• pp.232-239
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• 2009

This study presented the effect of membrane thickness on hydrogen permeability. Microvoids on the surface of the membrane should not exist for the exact values of hydrogen permeability. Pd-Cu-Ni hydrogen alloy membranes were fabricated by Ni powder sintering, substrate plasma pretreatment, sputtering and Cu reflow process. And this leaded to void-free surface and dense film of Pd-Cu-Ni hydrogen alloy membrane. Hydrogen permeation test showed that hydrogen permeability increased from 2.7 to $15.2ml/cm^2{\cdot}min{\cdot}atm^{0.5}$ as membrane thickness decreased from 12 to $4{\mu}m$. This represented the similar trend as a hydrogen permeability of pure palladium membrane based on solution-diffusion mechanism.

• 한국수소및신에너지학회논문집
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• 제24권3호
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• pp.200-205
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• 2013

The separation of hydrogen depends on porosity, diffusivity and solubility in permeation membrane. Dense membrane is always showing a solution diffusion mechanism but porous membrane is not showing. Therefore, porous membrane has a good hydrogen flux due to pore is carried out transferred media. This mechanism is named as the Knudsen diffusion. Hydrogen molecules or hydrogen atoms are diffused along pore that is a mean free path. In this study, complex layer hydrogen permeation membrane was fabricated by hot press process. And then, it was evaluated and calculated to relationship between hydrogen permeability and membrane porosity.

• 한국수소및신에너지학회논문집
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• 제13권3호
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• pp.249-258
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• 2002

Thermochemical water-splitting IS(Iodine-Sulfur) process has been investigating for large-scale hydrogen production. For the construction of an efficient process scheme, two kinds of membrane technologies are under investigating to improve the hydrogen producing HI decomposition step. One is a concentration of HI in quasi-azeotropic HIx ($HI-H_2O-I_2$) solution by elecro-electrodialysis. It was confirmed that HI concentrated from the $HI-H_2O-I_2$ solution with a molar ratio of 1:5:1 at $80^{\circ}C$. The other is a membrane reactor to enhance the one-pass conversion of thermal decomposition reaction of gaseous hydrogen iodide (HI). It was found from the simulation study that the conversion of over 0.9 would be attainable using the membrane reactor using the gas permeation properties of the prepared silica hydrogen permselective membrane by chemical vapor deposition (CVD). Design criterion of the membrane reactor was also discussed.

• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.177-183
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• 2020

To utilize hydrogen energy, high-yield, high-purity hydrogen needs to be produced; therefore, hydrogen separation membrane studies are being conducted. The membrane reactor that fabricates hydrogen needs to have high hydrogen permeability, selective permeability, heatresistant and a stable mechanical membrane. Dense membranes of Pd and Pd alloys are usually used, but these have drawbacks associated with high cost and durability. Therefore, many researchers have studied replacing Pd and Pd alloys. Dense TiN membrane is highly selective and can separate high-purity hydrogen. The porous alumina has a high permeation rate but low selectivity; therefore, separating high-purity hydrogen is difficult. To overcome this drawback, the two materials are combined as composite reclamations to produce a separation membrane with a high penetration rate and high selectivity. Accordingly, TiN-alumina was manufactured using a high-energy ball mill. The TiN-alumina membrane was characterized by X-ray diffraction analysis, scanning electron microscopy, and energy dispersive spectroscopy. The hydrogen permeability of the TiN-alumina membrane was estimated by a Sievert-type hydrogen permeation membrane apparatus. Due to the change in the diffusion mechanism, the transmittance value was lower than that of the general TiN ceramic separator.

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.219-227
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• 2021

Hydrogen isotopes, which are used as raw materials in fusion reaction, participate in the reaction only in small amount, and most of them are released together with impurities. In order to recover and reuse only hydrogen isotopes from this exhaust gas, a recovery process is required, and most of the hydrogen isotopes can be recovered using a Pd Membrane. In this study, the recovery rate of hydrogen isotopes was measured through the first and second stage Pd membrane experiments. In the case of the experiment using a single stage Pd membrane, about 99.2%, and in the case of the first stage and second stage Pd membrane connection experiments, a recovery rate of 99.9% or more was obtained. Therefore, the recovery rate of Pd membrane process applied to hydrogen can be applied to hydrogen isotopes. In addition, the simulation model was established using aspen custom modeler, a commercial software, and the validity of the simulation was checked by applying the references and experimental data. The simulation results based on the experimental data showed a difference of 2% or less.

• 공업화학
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• 제25권2호
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• pp.204-208
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• 2014

본 연구는 1차원 반응기 모델을 이용한 수치 시뮬레이션을 통해 수소투과량, 수소선택도, 사용된 촉매의 양, 급송흐름에서의 $H_2O/CO$ 조성비 및 Ar sweep gas가 막반응기(membrane reactor)에서의 수성가스전이반응의 성능에 미치는 영향을 분석하였다. 막반응기에서 평형상태보다 향상된 수소수율을 얻기 위해선 적어도 100 이상의 수소선택도를 가져야 함이 관찰되었으며, 수소투과량이 계속 증가될 경우에는 수소수율의 증가폭이 점차 감소됨이 보였다. 낮은 수소투과량의 경우에는 촉매량이 증가할수록 초기엔 증가된 CO 전환율을 보이다가 점차 그 증가폭이 감소되었으며, 높은 수소투과량의 경우에는 촉매의 양과 무관하게 높은 CO 전환율이 관찰되었다. 급송흐름에서의 $H_2O/CO$ 조성비가 1.5 이상인 경우엔 수소투과량이 막반응기에서의 CO 전환율에 미치는 영향이 미미하였고, 막반응기에서 평형상태보다 향상된 CO 전환율을 얻기 위해선 적어도 $6.7{\times}10^{-6}mol\;s^{-1}$ 의 Ar 몰유속이 필요함이 밝혀졌다.

• 멤브레인
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• 제34권2호
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• pp.140-145
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• 2024

에너지 패러다임의 변화가 요구되는 현대에 수소는 매력적인 에너지원이다. 이러한 수소를 정제하는 기술 중에서 분리막을 이용한 기술은 저비용으로 고순도의 수소를 정제할 수 있는 기술로 주목받고 있다. 그러나 수소 분리 성능이 뛰어난 팔라듐(Pd)은 가격이 매우 비싸 이를 대체한 소재가 필요하다. 본 연구에서는 수소 투과 성능은 좋으나 수소 취성에 약한 니오븀(Nb)과 수소 투과 성능은 떨어지나 내구성이 뛰어난 니켈(Ni)과 지르코늄(Zr)을 혼합한 합금으로 분리막을 제조하여 1~4 bar, 350~450 ℃ 조건에서 수소 투과 특성을 확인하였다. Pd를 코팅하지 않은 Ni₄₈Nb₃₂Zr₂₀ 분리막의 경우 최대 0.69 ml/cm²/min의 투과량을 보였으며, Pd가 코팅된 경우에는 최대 13.05 ml/cm²/min의 투과량을 보였다.

• 멤브레인
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• 제28권5호
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• pp.297-306
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• 2018

본 총설은 분리막기술이 적용된 수소생산에 대한 개론으로, 특히, 암모니아를 수소운반체로 이용하는 수소생산에 대한 연구결과를 중점적으로 서술하였다. 암모니아를 수소운반체로 적용한 수소생산은 추가적인 탄소생성이 없다는 점 외에 여러 측면에 있어 이점이 있다. 많은 연구들이 고순도 수소 분리 및 생산을 위한 분리막 개발을 위해 진행되고 있으며, 이들 중 팔라듐을 기본으로 한 분리막(예를 들어, 다공성 세라믹 또는 다공성 금속 지지체와 팔라듐 합금의 얇은 선택층으로 이루어진 분리막)에 대한 연구가 활발하다. 반면에, 효율적인 암모니아 분해를 위해서는 주로 루테늄 촉매가 적용되고 있으며, 루테늄과 지지체 및 촉진제로 이루어진 루테늄에 기반을 둔 촉매에 대한 연구발표가 다수 존재한다. 수소생산을 위한 분리막 반응기 형태로는 충전층, 유동층, 그리고 마이크로반응기 등이 있으며, 이들의 최적화 및 원활한 물질전달 연구는 현재진행형이다. 또한, 높은 암모니아 분해율, 고순도 수소생산 및 높은 수소생산율을 얻기 위해 분리막과 촉매의 다양한 조합에 대한 연구 및 분리막과 촉매의 역할을 동시에 구현할 수 있는 분리막에 대한 연구가 발표되고 있다.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.674-678
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• 2002

The dehydrogenation of propane to propylene has been studied in an isothermal high-temperature shell-and-tube membrane reactor containing a Pd-coated ${\psi}$-Al2O3 membrane and a Pt/K/Sn/Al2O3 packed catalyst . A tubular Pd-coated ${\psi}$-Al2O3 membrane was prepared by an electroless plating method. This membrane showed high hydrogen to nitrogen permselectivities (PH2N2 = 10-50) at 400 $^{\circ}C$ and 500 $^{\circ}C$ with various transmembrane pressure drops. The employment of a membrane reactor in the dehydrogenation reaction, which selectively separates hydrogen from the reaction mixture along the reaction path, can greatly increase the conversion and enable operation of the reactor at lower temperatures. High hydrogen permselectivity has been confirmed as a key factor in determining the reactor performance of conversion enhancement.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.336-339
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• 2006

With the steady depletion off fossil fuel reserves, hydrogen based energy sources become increasingly attractive. Therefore hydrogen production or separation technologies, such as Bas separation membrane based on adsorption technology, have received enormous attention in the industrial and academic fields. In this study, the transport mechanisms of the MTES (methyltriethoxysilane) templating silica/a-alumina composite membrane were evaluated by using unary, binary and quaternary hydrogen gas mixtures permeation experiments at unsteady- and steady-states. Since the permeation flux in the MTES membrane, through the experimental and theoretical study, was affected by molecular sieving effects as well as surface diffusion properties, the kinetic and equilibrium separation should be considered simultaneously in the membrane according to molecular properties. In order to depict the transient multi-component permeation on the templating silica membrane, the GMS (generalized Maxwell-Stefan) and DGM (dust Bas model) were adapted to unsteady-state material balance