• Journal of the Korean institute of surface engineering
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• v.37 no.5
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• pp.289-295
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• 2004

A dense palladium-nikel (Pd-Ni) alloy composite membrane has been fabricated on microporous nickel support mixed with submicron/micron nickel powder instead of mesoporous stainless steel support. Plasma treatment process is introduced as pre-treatment process instead of HCI activation. Pd-Ni alloy composite membrane prepared by electro plating was fairly a uniform and dense surface morphology. The membrane was characterized by permeation experiments with hydrogen and nitrogen gases at temperature 773 K and pressure 2.2 psi. The results showed that hydrogen ($H_2$) permeance was 27 ml/$\textrm{cm}^2$ㆍatmㆍmin and hydrogen/ nitrogen ($_H2$$N_2$) selectivity was 8 at 773 K.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.119-123
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• 2005

The thermochemical splitting of water has been proposed as a clean method for hydrogen production. The IS process is one of the thermochemical water splitting processes using iodine and sulfur as reaction agents. HI decomposition procedure to obtain hydrogen is one of the key operations in the process, because equilibrium conversion of HI is low (22% at $450^{\circ}C$). The silica membranes prepared by CVD. method were applied to the decomposition reaction of HI vapor. The permeation characteristics of hydrogen and nitrogen belong to the Knudsen flow pattern.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.196-200
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• 2018

In this study, the intermediate layer in Pd-based hydrogen separation membrane was synthesized to minimize the surface roughness and defects using powder-type and sol-type metal oxides. The surface properties and gas permeation characteristics were analysed by SEM and $N_2$ gas permeation test. The coating layer composed of sol type metal oxides has smooth surface, especially the layer coated by $TiO_2$ sol has little pin holes, cracks and defects. The binary layer composed of powder type and sol type metal oxides has similar flux characteristics to a single sol type layer. The Pd-based composite membrane improved by the binary intermediate layer exhibited $0.32mol/m^2s$ of the hydrogen permeation flux with a selectivity ($H_2/N_2$) of ~10,890 at 672 K and a pressure difference of 1 bar.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.269-272
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• 2015

$La_2Ce_2O_7$ and $CeO_2$ membranes were fabricated from the corresponding powders derived from sol-gel process with polyvinyl alcohol binder. These powders and membranes were characterized by XRD, BET, and FE-SEM analysis. Hydrogen and CO gas permeation experiments were performed using Sievert's type equipment. Both fluxes on these membranes were found to decrease with increase of the temperature. This phenomenon was followed by the surface and Knudsen diffusion mechanism. The hydrogen permeability of the $La_2Ce_2O_7$ membrane was found to be $7.27{\times}10^{-5}mol/m^2sPa$, with perm-selectivity of 7.24 at 303 K.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.451-453
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• 2013

Porous ceramic membranes consisting of $Ce_{1-x}Y_xO_{2-{\delta}}$ were developed for hydrogen permeation tests. Various amounts (x = 0, 0.05, 0.1, 0.2) of yttrium were doped to ceria to study the effect of yttrium doping on ceria membranes on various properties, including hydrogen permeability. $Ce_{1-x}Y_xO_{2-{\delta}}$ powder was synthesized by the sol-gel method. These membranes were fabricated by pressing and sintering at $1300^{\circ}C$ for 6 h. As the amount of yttrium increased, the grain size of the membrane decreased. Hydrogen permeability was improved as the yttrium content increased. Selective permeability of hydrogen compared to CO is explained by electric conductivity. As the temperature rose, both the hydrogen perm-selectivity and electric conductivity on $Ce_{0.8}Y_{0.2}O_{1.9}$ improved.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.66-70
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• 2005

For the application in HI decomposition reaction of thermochemical water-splitting IS process, the carbonized membranes using the polymer material (polyimide) were prepared, and SiC membrane was also prepared by SiO treatment on those carbonized membranes. The weight change by the carbonation of polyimide was about 50%, and the weight decreased with an increase of carbonation temperature. The gas permeance ($H_2$ or $N_2$) of carbonized membrane decreased with an increase of carbonation temperature led to the pore closing. The gas permeance ($H_2$ or $N_2$) of SiC membrane increased with an increase of SiO treatment concentration, and the gas permeation mechanism was changed from the activiation energy flow to Knudsen flow.

• Journal of the Korean institute of surface engineering
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• v.37 no.5
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• pp.243-248
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• 2004

A palladium-nikel(Pd-Ni) alloy composite membrane has been fabricated on microporous nickel support formed with nickel powder. Plasma surface treatment process is introduced as pre-treatment process instead of HCI activation. Pd coating layer was prepared by dc magnetron sputtering deposition after $H_2$ plasma surface treatment. Palladium-nickel alloy composite layer had a fairly uniform and dense surface morphology. The membrane was characterized by permeation experiments with hydrogen and nitrogen gases at temperature of 773 K and pressure of 2.2psi. The hydrogen permeance was 6 ml/minㆍ$\textrm{cm}^2$ㆍatm and the selectivity was 120 for hydrogen/nitrogen($H_2$/$N_2$) mixing gases at 773 K.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.442-445
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• 1999

In this work, to detect of hydrogen in DI water in the generator area of nuclear power plants was fabricated Pd/Pt gate MISFET sensor using Pd membrane. $H_2$ permeation through Pd accounts for external mass transfer, surface adsorption and desorption, transitions to and from the bulk metal, and diffusion within the metal. The identification of pinholes in the generator area of plant is an important safety consideration, as hydrogen build-up gives rise to explosion. For this type of application the sensor needs to be isolated in DI water, accordingly, a Pd membrane was used to separate the DI water. The hydrogen in the DI water was then absorbed on the Pd thin film and diffused into the oil through the thin film. The Pd/Pt gate MISFET sensor, encapsulated by oil, will thereby detect permeated hydrogen.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.458-464
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• 2011

Recently, one of the hydrogen production methods has attracted using dense metallic membrane. It has high hydrogen permeation and selectivity which hardly could adopt industrial product because of high cost, hydrogen embrittlment and thermal stability. Meanwhile, vanadium has high hydrogen solubility and it use to instead of Pd-Ag amorphous membrane. Aluminum carried out blocking hydrogen diffusion on grain boundary therefore protecting hydrogen embrittlement. Most of dense metallic membrane is solution diffusion mechanism. The solution diffusion mechanism was very similar hydrogen storing steps such as steps of metal hydride. Thus, V-Al composites were fabricated to use hydrogen induced mechanical alloying. The fabricated V-Al composites were characterized by XRD, SEM, EDS and simultaneous TG/DSC analyses. The hydrogenation behaviors were evaluated using a Sievert's type automatic PCT apparatus. The hydrogenation behaviors of V-Al composites was evaluated too low hydrogen stored capacity and fast hydrogenation kinetics. In PCI results, V-Al composites had low hydrogen solubility, in spite of that, hydrogen kinetics was calculated very fast and hydrogen absorption/desorption contents were same capacity.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.1
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• pp.29-35
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• 2013

A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.