Thermal Degradation Behavior of Hydrogen Permeability of Pd-Coated V-Alloy Membrane for Hydrogen Separation and Purification

2021 ◽  
Vol 1016 ◽  
pp. 1710-1714
Author(s):  
Hiroshi Yukawa ◽  
Tomonori Nambu ◽  
Yoshihisa Matsumoto
Keyword(s):  
Thermal Activation ◽  
Hydrogen Permeability ◽  
Testing Temperature ◽  
Hydrogen Separation ◽  
Activation Process ◽  
Degradation Behavior ◽  
Separation And Purification ◽  
Accelerated Degradation ◽  
Thermal Degradation Behavior ◽  
Thermal Activation Process

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.

scholarly journals Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 282
Author(s):  
Leandri Vermaak ◽  
Hein W. J. P. Neomagus ◽  
Dmitri G. Bessarabov
Keyword(s):  
Hydrogen Permeability ◽  
Gas Mixtures ◽  
Open Circuit ◽  
Hydrogen Separation ◽  
Proton Exchange ◽  
Limiting Current ◽  
Separation Performance ◽  
Separation And Purification ◽  
Irreversible Damage ◽  
Temperature Range

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.

scholarly journals Dissolution Process Observation of Methane Bubbles in the Deep Ocean Simulator Facility

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3938
Author(s):  
Tsutomu Uchida ◽  
Ike Nagamine ◽  
Itsuka Yabe ◽  
Tatsunori Fukumaki ◽  
Ai Oyama ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Thermal Activation ◽  
Pure Water ◽  
Deep Ocean ◽  
Ccd Camera ◽  
Activation Process ◽  
Thermal Activation Process ◽  
Methane Bubble ◽  
Expected Values ◽  
Process Observation

To investigate the temperature dependency of the methane bubble dissolution rate, buoyant single methane bubbles were held stationary in a countercurrent water flow at a pressure of 6.9 MPa and temperatures ranging from 288 K to 303 K. The 1 to 3 mm diameter bubbles were analyzed by observation through the pressure chamber viewport using a bi-telecentric CCD camera. The dissolution rate in artificial seawater was approximately two times smaller than that in pure water. Furthermore, it was observed that the methane bubble dissolution rate increased with temperature, suggesting that bubble dissolution is a thermal activation process (the activation energy is estimated to be 9.0 kJ/mol). The results were different from the expected values calculated using the governing equation for methane dissolution in water. The dissolution modeling of methane bubbles in the mid-to-shallow depth of seawater was revised based on the current results.

Characterization of Tetrahedrally Bonded Amorphous Carbon Via Capacitance Techniques

1998 ◽  
Vol 508 ◽  
Author(s):  
Kimon C. Palinginis ◽  
A. Ilie ◽  
B. Kleinsorge ◽  
W.I. Milne ◽  
J. D. Cohen
Keyword(s):  
Amorphous Carbon ◽  
Thermal Activation ◽  
Activation Process ◽  
Defect States ◽  
Capacitance Measurements ◽  
Tetrahedral Amorphous Carbon ◽  
Thermal Activation Process ◽  
Order Of Magnitude ◽  
Defect Densities

AbstractWe report the results of junction capacitance measurements on thin tetrahedral amorphous carbon (ta-C) films to deduce their defect densities. We find defect densities in the range 3 - 7 × 1017 cm−3 in the undoped ta-C films, and roughly an order of magnitude larger in the nitrogen doped (n-type) films. In some cases fairly uniform defect profiles were obtained covering a thickness of a couple of hundreds angstroems. We also observed a thermal activation process of carriers from defect states at the ta-C/c-Si interface with an activation energy in the range of 0.4eV to 0.5eV.

Sims study of Ti–Zr–V NEG thermal activation process

Vacuum ◽  
2005 ◽  
Vol 80 (1-3) ◽  
pp. 47-52 ◽  
Author(s):  
J. Drbohlav ◽  
I. Matolínová ◽  
K. Mašek ◽  
V. Matolín
Keyword(s):  
Thermal Activation ◽  
Activation Process ◽  
Thermal Activation Process

Reverse Dependence of Ge Surface Segregation on Growth Temperature in Si-Mbe

1990 ◽  
Vol 202 ◽  
Author(s):  
Kiyokazu Miyao ◽  
Masanobu Miyao
Keyword(s):  
Growth Temperature ◽  
Thermal Activation ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Activation Process ◽  
Surface Migration ◽  
Good Crystallinity ◽  
Thermal Activation Process ◽  
Temperature Dependences ◽  
Reverse Dependence

ABSTRACTGe surface segregation on Si(100) and Si(111) substrates during silicon molecular beam epitaxy is studied as a function of growth temperature. During growth, the Ge atoms are partly incorporated into the growing layer and the residuals segregate on the grown surface. The incorporation coefficient cannot be expressed in terms of a simple thermal activation process. That is, the Ge segregation phenomena increase to maxima at around 450°C for the Si(100) substrates and at around 650°C for the Si(111) substrates. Segregation decreases above these temperatures. These reverse temperature dependences enable not only good crystallinity of the heteroepitaxial layer, but also abrupt heterointerfaces. The incorporation coefficients for Si(111) are much larger than those for Si(100), which is explained by a model based on surface migration.

The thermal activation process of coal gangue selected from Zhungeer in China

2016 ◽  
Vol 126 (3) ◽  
pp. 1559-1566 ◽  
Author(s):  
Lixin Li ◽  
Yinmin Zhang ◽  
Yongfeng Zhang ◽  
Junmin Sun ◽  
Zhifei Hao
Keyword(s):  
Thermal Activation ◽  
Coal Gangue ◽  
Activation Process ◽  
Thermal Activation Process
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