Hydriding Reaction of LaNi5: Correlations between Thermodynamic States and Sorption Kinetics during Activation

2011 ◽  
pp. 107-115
Author(s):  
P Millet ◽  
C Lebouin ◽  
R Ngameni ◽  
A Ranjbari ◽  
M Guymont
Keyword(s):  
Sorption Kinetics ◽  
Hydriding Reaction

scholarly journals Hydriding Reaction of LaNi5: Correlations between Thermodynamic States and Sorption Kinetics during Activation

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
P. Millet ◽  
C. Lebouin ◽  
R. Ngameni ◽  
A. Ranjbari ◽  
M. Guymont
Keyword(s):  
Diffusion Coefficient ◽  
Hydrogen Diffusion ◽  
Research Work ◽  
Sorption Isotherms ◽  
Sorption Kinetics ◽  
Activation Process ◽  
Process Step ◽  
Hydrogen Diffusion Coefficient ◽  
Model Equations ◽  
Hydriding Reaction

This research work concerns the hydriding reaction of LaNi5 during the first hydriding cycles (activation process). Step-by-step sorption isotherms (Δ[H/M]≈0.03) were measured at 298 K, in the composition range 0<H/M<2.0, at the beginning (first hydriding cycle, where hysteresis is maximum) and at the end (tenth hydriding cycle, where hysteresis is minimum) of the activation process, offering the possibility to correlate thermodynamic states (pressure-composition data points) to sorption kinetics. Using pneumatochemical impedance spectroscopy (PIS), experimental impedance diagrams were obtained for each data point of the isotherms. Microscopic rate parameters such as surface resistance and hydrogen diffusion coefficient were obtained as a function of composition, by fitting appropriate model equations to experimental impedances. It is found that the high-frequency pneumatochemical resistance significantly decreases during activation. This is correlated with the surface increase of the solid-gas interface area. The hydrogen diffusion coefficient is found to be larger at the beginning of the activation process and lower on a fully activated sample.

Helium recovery and blanketing effect with the hydriding reaction of ZrCo

2021 ◽  
Vol 170 ◽  
pp. 112458
Author(s):  
Pil-Kap Jung ◽  
Min Ho Chang ◽  
Dong-you Chung ◽  
Hyun-Goo Kang ◽  
Jea-Uk Lee
Keyword(s):  
Hydriding Reaction

Modeling of sorption kinetics of U(VI) micro-quantities nanostructured materials with anatase mesoporous structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Veniamin Zheleznov ◽  
Aleksey Golikov ◽  
Tatiana Sokolnitskaya ◽  
Sergey Ivannikov
Keyword(s):  
Nanostructured Materials ◽  
Sorption Kinetics ◽  
Uranyl Ion ◽  
Competitive Sorption ◽  
Hydroxyl Groups ◽  
Complex Ions ◽  
The Stability ◽  
Kinetics Of ◽  
Mesoporous Structures ◽  
Ionic Forms

Abstract The sorption kinetics of uranyl ions micro-quantities from fluoride solutions by nanostructured materials with anatase mesoporous structures has been studied. Using the model of competitive sorption of ions and positively charged complexes of uranyl ion on deprotonated hydroxyl groups of an anatase, kinetic curves of changes in the ratio of ionic forms of uranium in solution were calculated. Modeling was carried out under the assumption of a two-stage mechanism of uranium complex ions sorption. The modeling considered the influence of the uranyl ion carbonate complexes formation. The shift in equilibrium among ionic forms of uranyl correlates with the stability of the complexes in solution.

Nanocrystalline Mg-based hydrides for hydrogen storage

2001 ◽  
Vol 676 ◽  
Author(s):  
W. Oelerich ◽  
T. Klassen ◽  
R. Bormann
Keyword(s):  
Hydrogen Storage ◽  
Mobile Applications ◽  
Research Effort ◽  
Metal Hydrides ◽  
Clean Energy ◽  
High Energy ◽  
Sorption Kinetics ◽  
Desorption Kinetics ◽  
Gaseous State ◽  
Sorption Behaviour

ABSTRACTHydrogen is the ideal means of energy storage for transportation and conversion of energy in a comprehensive clean-energy concept. However, appropriate storage facilities, both for stationary and for mobile applications, are complicated, because of the very low boiling point of hydrogen (20.4 K at 1 atm) and its low density in the gaseous state (90 g/m3). Furthermore, the storage of hydrogen in liquid or gaseous form imposes safety problems, in particular for mobile applications, e.g. the future zero-emission vehicle. Metal hydrides are a safe alternative for H-storage and, in addition, have a high volumetric energy density that is about 60% higher than that of liquid hydrogen. Mg hydride has a high storage capacity by weight and is therefore favoured for automotive applications. However, so far light metal hydrides have not been considered competitive because of their rather sluggish sorption kinetics. Filling a tank could take several hours. Moreover, the hydrogen desorption temperature of about 300 °C is rather high for most applications. A breakthrough in hydrogen storage technology was achieved by preparing nanocrystalline hydrides using high-energy ball milling. These new materials show very fast aband desorption kinetics within few minutes, thus qualifying lightweight Mg-based hydrides for storage application. In this paper recent detailed results on the sorption behaviour of nanocrystalline Mg and Mg-based alloys are presented. In a following research effort the sorption kinetics of nanocrystalline Mg has been further enhanced by catalyst additions. Furthermore, different transition metals have been added to Mg to achieve a thermodynamic destabilisation of the hydride, thus lowering the desorption temperatures to about 230 °C. The newly developed materials are currently being tested in prototype storage tanks.

Assessing polymer sorption kinetics using micromachined resonators

2011 ◽  
Author(s):  
J.-J. Su ◽  
C. Carron ◽  
S. Truax ◽  
K.S. Demirci ◽  
L.A. Beardslee ◽  
...  
Keyword(s):  
Sorption Kinetics ◽  
Polymer Sorption

Model-based prediction of the moisture sorption kinetics and humidity-induced collapse for freeze–dried cakes

2022 ◽  
Vol 248 ◽  
pp. 117129
Author(s):  
Kyuya Nakagawa ◽  
Hiroki Kamisaki ◽  
Tetsuo Suzuki ◽  
Noriaki Sano
Keyword(s):  
Moisture Sorption ◽  
Sorption Kinetics ◽  
Model Based ◽  
Freeze Dried

Sorption Kinetics in Finite-Bath Systems

1972 ◽  
Vol 98 (6) ◽  
pp. 1021-1036
Author(s):  
Francis A. DiGiano ◽  
Walter J. Weber
Keyword(s):  
Sorption Kinetics
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