On the use temperature parameterized rate coefficients in the estimation of non-equilibrium reaction rates

2006 ◽  
Vol 365 (2) ◽  
pp. 317-332 ◽  
Author(s):  
Bernie D. Shizgal ◽  
Aziz Chikhaoui
Keyword(s):  
Reaction Rates ◽  
Rate Coefficients ◽  
Equilibrium Reaction ◽  
Non Equilibrium

DSMC Predictions of Non-equilibrium Reaction Rates

2011 ◽  
Author(s):  
R. B. Bond ◽  
M. A. Gallis ◽  
J. R. Torczynski
Keyword(s):  
Reaction Rates ◽  
Equilibrium Reaction ◽  
Non Equilibrium

scholarly journals Electrolyte-Assisted Hydrogen Cycling in Lithium and Sodium Alanates at Low Pressures and Temperatures

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5868
Author(s):  
Jason Graetz ◽  
John J. Vajo
Keyword(s):  
Growth Parameters ◽  
Reaction Times ◽  
Hydrogen Uptake ◽  
Hydrogen Desorption ◽  
Reaction Rates ◽  
Rate Coefficients ◽  
Aluminum Hydrides ◽  
Dehydrogenation Reactions ◽  
Low Pressures ◽  
Sodium Alanates

An investigation of electrolyte-assisted hydrogen storage reactions in complex aluminum hydrides (LiAlH4 and NaAlH4) reveals significantly reduced reaction times for hydrogen desorption and uptake in the presence of an electrolyte. LiAlH4 evolves ~7.8 wt% H2 over ~3 h in the presence of a Li-KBH4 eutectic at 130 °C compared to ~25 h for the same material without the electrolyte. Similarly, NaAlH4 exhibits 4.8 wt% H2 evolution over ~4 h in the presence of a diglyme electrolyte at 150 °C compared to 4.4 wt% in ~15 h for the same material without the electrolyte. These reduced reaction times are composed of two effects, an increase in reaction rates and a change in the reaction kinetics. While typical solid state dehydrogenation reactions exhibit kinetics with rates that continuously decrease with the extent of reaction, we find that the addition of an electrolyte results in rates that are relatively constant over the full desorption window. Fitting the kinetics to an Avrami-Erofe’ev model supports these observations. The desorption rate coefficients increase in the presence of an electrolyte, suggesting an increase in the velocities of the reactant-product interfaces. In addition, including an electrolyte increases the growth parameters, primarily for the second desorption steps, resulting in the observed relatively constant reaction rates. Similar effects occur upon hydrogen uptake in NaH/Al where the presence of an electrolyte enables hydrogenation under more practical low temperature (75 °C) and pressure (50 bar H2) conditions.

scholarly journals Ammonia Synthesis via Non-Equilibrium Reaction of Lithium Nitride in Hydrogen Flow Condition

2013 ◽  
Vol 77 (12) ◽  
pp. 580-584
Author(s):  
Kiyotaka Goshome ◽  
Hiroki Miyaoka ◽  
Tomoyuki Ichikawa ◽  
Takayuki Ichikawa ◽  
Yoshitsugu Kojima
Keyword(s):  
Flow Condition ◽  
Ammonia Synthesis ◽  
Lithium Nitride ◽  
Hydrogen Flow ◽  
Equilibrium Reaction ◽  
Non Equilibrium

scholarly journals Transport-controlled reaction rates under local non-equilibrium conditions

2007 ◽  
Vol 34 (10) ◽  
Author(s):  
Xavier Sanchez-Vila ◽  
Marco Dentz ◽  
Leonardo David Donado
Keyword(s):  
Reaction Rates ◽  
Equilibrium Conditions ◽  
Non Equilibrium
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