scholarly journals Effects of low Ag additions on the hydrogen permeability of Pd–Cu–Ag hydrogen separation membranes

2014 ◽  
Vol 451 ◽  
pp. 216-225 ◽  
Author(s):  
Shahrouz Nayebossadri ◽  
John Speight ◽  
David Book
2004 ◽  
Vol 835 ◽  
Author(s):  
S.-J. Song ◽  
T. H. Lee ◽  
L. Chen ◽  
C. Zuo ◽  
S. E. Dorris ◽  
...  

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.


Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 282
Author(s):  
Leandri Vermaak ◽  
Hein W. J. P. Neomagus ◽  
Dmitri G. Bessarabov

This paper reports on an experimental evaluation of the hydrogen separation performance in a proton exchange membrane system with Pt-Co/C as the anode electrocatalyst. The recovery of hydrogen from H2/CO2, H2/CH4, and H2/NH3 gas mixtures were determined in the temperature range of 100–160 °C. The effects of both the impurity concentration and cell temperature on the separation performance of the cell and membrane were further examined. The electrochemical properties and performance of the cell were determined by means of polarization curves, limiting current density, open-circuit voltage, hydrogen permeability, hydrogen selectivity, hydrogen purity, and cell efficiencies (current, voltage, and power efficiencies) as performance parameters. High purity hydrogen (>99.9%) was obtained from a low purity feed (20% H2) after hydrogen was separated from H2/CH4 mixtures. Hydrogen purities of 98–99.5% and 96–99.5% were achieved for 10% and 50% CO2 in the feed, respectively. Moreover, the use of proton exchange membranes for electrochemical hydrogen separation was unsuccessful in separating hydrogen-rich streams containing NH3; the membrane underwent irreversible damage.


2012 ◽  
Vol 37 (1) ◽  
pp. 894-902 ◽  
Author(s):  
Jianjun Ye ◽  
Jian Yang ◽  
Jinyang Zheng ◽  
Xianting Ding ◽  
Ieong Wong ◽  
...  

2021 ◽  
Author(s):  
Wei Liu ◽  
Ming Yang ◽  
Jing Liu ◽  
Meijia Yang ◽  
Jing Li ◽  
...  

Abstract The unique magnetic, electronic and optical features derived from their unpaired electrons have made radical polymers an attractive material platform for various applications. Here, we report solution-processable radical polymer membranes with multi-level porosities and study the impact of free radicals on important membrane separation processes including solar vapor generation, hydrogen separation and CO2 capture. The radical polymer is a supreme light absorber over the full solar irradiation range with sufficient water transport channels, leading to a highly efficient solar evaporation membrane. In addition, the radical polymer with micropores and adjustable functional groups are broad-spectrum gas separation membranes for both hydrogen separation and CO2 capture. First principle calculations indicate that the conjugated polymeric network bearing radicals is more chemically reactive with CO2, compared with H2, N2 and CH4. This is evidenced by a high CO2 permeability in gas separation membranes made of the conjugated radical polymer.


2011 ◽  
Vol 179-180 ◽  
pp. 1309-1313 ◽  
Author(s):  
Xiao Liang Zhang ◽  
Xu Feng Xie ◽  
Yan Huang

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.


2021 ◽  
Vol 1016 ◽  
pp. 1710-1714
Author(s):  
Hiroshi Yukawa ◽  
Tomonori Nambu ◽  
Yoshihisa Matsumoto

A series of accelerated degradation experiments at high temperatures have been performed for Pd-coated V-10 mol% Fe alloy membranes in order to investigate the degradation behavior of hydrogen permeability. The degradation of the membrane becomes severer with increasing testing temperature. The temperature dependence of the 20% degradation rate almost obeys the Arrhenius relationship, suggesting that the degradation phenomenon occurs by a kind of thermal activation process. It is found that the addition of a small amount of W into Pd overlayer improves the durability of the membrane significantly.


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