Electrical and Hydrogen Transport Properties of SrCe0.8Yb0.2O3−δ/Ni Cermet Membranes

2004 ◽  
Vol 835 ◽  
Author(s):  
S.-J. Song ◽  
T. H. Lee ◽  
L. Chen ◽  
C. Zuo ◽  
S. E. Dorris ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Hydrogen Permeation ◽  
Electron Flow ◽  
Hydrogen Permeability ◽  
Permeation Rate ◽  
Hydrogen Separation ◽  
Metal Composite ◽  
Conducting Oxides ◽  
Separation Membranes ◽  
Increasing Demand

AbstractResearch on hydrogen separation membranes is motivated by the increasing demand for an environmentally benign, inexpensive technology for separating hydrogen from gas mixtures. Although most studies of hydrogen separation membranes have focused on proton-conducting oxides by themselves, the addition of metal to these oxides increases their hydrogen permeability and improves their mechanical stability. This study began by determining the electrical and hydrogen permeation properties of SrCe0.8Yb0.2O3−δ (SCYb). The results showed that the hydrogen permeation rate is limited by electron flow at the investigated temperatures (600 – 900°C). To further enhance hydrogen permeability, a cermet (i.e., ceramic-metal composite) membrane was made by adding Ni to the SCYb. The cermet showed no phase change after sintering in a reducing atmosphere. At 900°C, with 20% H2 /balance He as a feed gas (pH2O = 0.03 atm), the hydrogen permeation rate was 0.113 cm3/min-cm2 for Ni/SCYb (0.43-mm thick) and 0.008 cm3/min-cm2 for SCYb (0.7-mm thick). The dependences of hydrogen permeability on temperature, thickness, and hydrogen partial pressure gradients are also determined. The results demonstrate that adding Ni to SCYb considerably increases its hydrogen permeability by increasing its electron conductivity.

Pure Ni and Pd-Ni Alloy Membranes Prepared by Electroless Plating for Hydrogen Separation

2011 ◽  
Vol 179-180 ◽  
pp. 1309-1313 ◽  
Author(s):  
Xiao Liang Zhang ◽  
Xu Feng Xie ◽  
Yan Huang
Keyword(s):  
Electroless Plating ◽  
Hydrogen Permeation ◽  
Hydrogen Permeability ◽  
Composite Membranes ◽  
Hydrogen Separation ◽  
High Hydrogen ◽  
Ni Alloy ◽  
Plating Method ◽  
Fcc Phase ◽  
The Ideal

Pd-based composite membranes are the attractive membrane materials for hydrogen separation due to their high hydrogen permeability and infinite permselectivity. Thin pure Ni and Pd-Ni alloy membranes with high hydrogen permeation were prepared by the electroless plating method. It is difficult to prepare the dense pure Ni membranes with 1-2 μm thickness for hydrogen separation. However, Pd-Ni alloy membranes with several micrometers thickness showed good permeation performance. Hydrogen permeance of the Pd95Ni5 alloy membrane with fcc phase up to 3.1×10-6 mol/m2 s Pa and the ideal permselectivity over 600 were obtained at 773 K.

Mixed-Conducting Membranes for Hydrogen Production and Separation

2006 ◽  
Vol 972 ◽  
Author(s):  
U. Balachandran ◽  
Beihai Ma ◽  
Tae H Lee ◽  
Sun-Ju Song ◽  
Ling Chen ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Hydrogen Permeability ◽  
Composite Membranes ◽  
Ceramic Membranes ◽  
Electronic Charge ◽  
Membrane Thickness ◽  
Pure Hydrogen ◽  
Metal Composite ◽  
Proton Conducting ◽  
Conducting Oxides

AbstractMixed-conducting oxides, possessing both ionic and electronic charge carriers, have found wide application in recent years in solid-state electrochemical devices that operate at high temperatures, e.g., solid-oxide fuel cells, batteries, and sensors. These materials also hold promise as dense ceramic membranes that separate gases such as oxygen and hydrogen from mixed-gas streams. We are developing Sr-Fe-Co oxide (SFC) as a membrane that selectively transports oxygen during partial oxidation of methane to syngas (mixture of CO and H2) because of SFC's high combined electronic and ionic conductivities. We have evaluated extruded tubes of SFC for conversion of methane to syngas in a reactor that was operated at ≈900°C. Methane conversion efficiencies were >90%, and some of the reactor tubes were operated for >1000 h. We are also developing dense proton-conducting oxides to separate pure hydrogen from product streams that are generated during methane reforming and coal gasification. Hydrogen selectivity in these membranes is nearly 100%, because they are free of interconnected porosity. Although most studies of hydrogen separation membranes have focused on proton-conducting oxides by themselves, we have developed cermet (i.e., ceramic-metal composite) membranes in which metal powder is mixed with these oxides in order to increase their hydrogen permeability. Using several feed gas mixtures, we measured the nongalvanic hydrogen permeation rate, or flux, for the cermet membranes in the temperature range of 500-900°C. This rate varied linearly with the inverse of membrane thickness. The highest rate, ≈32 cm3(STP)/min-cm2, was measured at 900°C for an ≈15-μm-thick membrane on a porous support structure when 100% H2 at ambient pressure was used as the feed gas.

Exceptional hydrogen permeation of all-ceramic composite robust membranes based on BaCe0.65Zr0.20Y0.15O3−δ and Y- or Gd-doped ceria

2015 ◽  
Vol 8 (12) ◽  
pp. 3675-3686 ◽  
Author(s):  
Elena Rebollo ◽  
Cecilia Mortalò ◽  
Sonia Escolástico ◽  
Stefano Boldrini ◽  
Simona Barison ◽  
...  
Keyword(s):  
Ceramic Composite ◽  
Hydrogen Permeation ◽  
Ceramic Composites ◽  
Hydrogen Separation ◽  
Doped Ceria ◽  
Separation Membranes ◽  
All Ceramic

Mixed proton and electron conductor ceramic composites were examined as hydrogen separation membranes at moderate temperatures (higher than 500 °C).

Characterization of ceramic-metal composite hydrogen separation membranes consisting of barium oxide, cerium oxide, yttrium oxide and palladium

2003 ◽  
Vol 217 (1-4) ◽  
pp. 43-49 ◽  
Author(s):  
R.V. Siriwardane ◽  
J.A. Poston ◽  
E.P. Fisher ◽  
T.H. Lee ◽  
S.E. Dorris ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Yttrium Oxide ◽  
Barium Oxide ◽  
Hydrogen Separation ◽  
Metal Composite ◽  
Separation Membranes

Preparation and Hydrogen Permeation on Al2O3-CuO-ZnO (ACZ)/Co Membrane by Hot Press Sintering (HPS)

2011 ◽  
Vol 695 ◽  
pp. 251-254 ◽  
Author(s):  
Saet Byol Rim ◽  
Kyeong Il Kim ◽  
Tae Whan Hong ◽  
Mie Won Jung
Keyword(s):  
Room Temperature ◽  
Hydrogen Permeation ◽  
Sol Gel ◽  
Hydrogen Permeability ◽  
Permeation Rate ◽  
Nitrate Hexahydrate ◽  
Distilled Water ◽  
Hot Press ◽  
Sol Gel Process ◽  
Hot Press Sintering

The Al2O3-CuO-ZnO (ACZ) was synthesized from sol-gel process with aluminum isopropoxide, copper (II) nitrate hemi pentahydrate, Zn (II) nitrate hexahydrate and primary distilled water. The ACZ synthesized powders were analyzed by TG/DTA, XRD, BET and FE-SEM. The ACZ-Co composites membrane was prepared by hot press sintering (HPS). Hydrogen permeability was characterized by Sievert's type hydrogen permeation membrane equipment. The hydrogen permeation rate was measured 0.0496 mol m-2 s-1 at room temperature under 2 bar of H2 atmosphere.

Evaluations of Hydrogen Permeation on TiN-20wt.%Co Membrane by Hot Press Sintering

2010 ◽  
Vol 297-301 ◽  
pp. 549-554
Author(s):  
Kyeong Il Kim ◽  
Sang Hern Kim ◽  
Whan Gi Kim ◽  
Soon Chul Ur ◽  
Tae Whan Hong
Keyword(s):  
Hydrogen Permeation ◽  
Operating Temperature ◽  
Hydrogen Permeability ◽  
Hydrogen Separation ◽  
Hot Press ◽  
New Materials ◽  
Practical Applications ◽  
Metal Ceramic ◽  
Polymer Metal ◽  
Hot Press Sintering

Nowadays, the most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, TiN powders are great in resistance to acids and chemically stable under high operating temperature. In order to get specimens for hydrogen permeation, the TiN powders synthesized were consolidated together with pure Co powders by hot press sintering. During the consolidation of powders at HPS, heating rate was 10K/min and the pressure was 10MPa. It was characterized by XRD, SEM, and BET. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.

Fabrications and Evaluations of Hydrogen Permeation on Al2O3-CuO-ZnO(ACZ)/Pd Coated Membrane

2011 ◽  
Vol 695 ◽  
pp. 255-258
Author(s):  
Kyeong Il Kim ◽  
Sung Woong Yoo ◽  
Na Ri Lee ◽  
Tae Whan Hong
Keyword(s):  
Hydrogen Production ◽  
High Purity ◽  
Ceramic Membrane ◽  
Hydrogen Permeation ◽  
Porous Ceramic ◽  
Hydrogen Permeability ◽  
Ceramic Composites ◽  
Hydrogen Separation ◽  
Porous Ceramic Membrane ◽  
High Purity Hydrogen

The most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, ceramic materials are great in resistance to acids and chemically stable under high operating temperature. Recent research in cermet materials for membrane applications interests to permeability and selectivity of hydrogen. High purity hydrogen can be produced through simple process by membrane. Recently, research in ceramic composites for membrane applications attract to hydrogen separation. Porous ceramic membrane process which has high permeability and hydrogen flux is chemically and thermally stable. Therefore, they are attractive for applications in hydrogen production process. However, porous ceramic membrane had low selectivity, hard to produce high purity hydrogen. Many studies were carried out Pd and Pd alloys coating, they were fabricated dense cermet membrane. In this work, ACZ ceramic membrane was fabricated disk type membrane by cold isostatic press (CIP) and then coated Pd and Pd-alloys.. It was characterized by XRD, SEM, EDX and BET. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.

Studies on Hydrogen Permeation of Weldments for Two Low-Alloyed Steels With Different Microstructures

2011 ◽  
Author(s):  
Jian Qun Tang ◽  
Jian Ming Gong
Keyword(s):  
Diffusion Coefficient ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Lath Martensite ◽  
Hydrogen Permeability ◽  
Diffusion Path ◽  
Permeation Rate ◽  
Liquefied Petroleum Gas ◽  
Boundary Area ◽  
And Diffusion

16MnR and SPV50Q low-alloyed steels, which have ferrite-pearlite and tempered martensite microstructures, respectively, are widely used to fabricate storage tanks for liquefied petroleum gas. However, during the process of operation, some cracks often occur on tanks made by these steels due to the presence of hydrogen, especially on weldments. The occurrence of this cracking is closely related to the diffusion and permeation of hydrogen in the steels. In order to explore the effect of different microstructures on hydrogen permeation and compare the hydrogen permeability of these two weldments, measurements were conducted on various metals (base metal-BM, heat-affected zone-HAZ, and welded metal-WM) cut from 16MnR and SPV50Q weldments by using electrochemical permeation tests. The results show that the microstructure has an important effect on hydrogen permeability. For 16MnR steel weldment, the diffusion coefficient of BM is the minimum due to the presence of the strong hydrogen traps in the interface between banded pearlite and matrix as well as the interface between inclusion and matrix. The microstructure of WM provides great grain boundary area as a hydrogen diffusion path and makes hydrogen easily diffuse, which results in the maximum permeation rate and diffusion coefficient. The fine-grained microstructure of normalized zone in HAZ acts as barriers for the hydrogen diffusion, which makes the permeation rate and diffusion coefficient of HAZ located between those of BM and WM. Similarly, for SPV50Q weldment, the permeation rate and diffusion coefficient increase in the order of BM, HAZ and WM. Those of BM are the minimum, which is correlated with the strong hydrogen trap due to the large quantities of dislocation within the lath martensite. Those of WM are the maximum for its strongly hydrogen diffusion path like WM of 16MnR weldment. As comparing the hydrogen permeability of 16MnR and SPV50Q weldment, the corresponding metals of the former always have greater permeation rate and diffusion coefficient than those of the latter, which is also due to its intrinsic microstructures.

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