scholarly journals Comparing hydrogen absorption kinetics of the samples of intermetallic compound and metal hydride compact on its basis

2021 ◽  
Vol 2057 (1) ◽  
pp. 012043
Author(s):  
I A Romanov ◽  
V I Borzenko ◽  
A N Kazakov
Keyword(s):  
Intermetallic Compound ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Reaction Rate ◽  
Nickel Foam ◽  
High Confidence ◽  
Compact Sample ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Absorption Of Hydrogen

Abstract This work is devoted to an experimental study and comparison of the kinetics of hydrogen absorption by an intermetallic compound LaNi4.4Al0.3Fe0.3 in form of pure intermetallic compound free backfill and a compact based on it obtained by cold pressing with a spiral matrix of nickel-foam. To calculate the kinetic parameters of the hydrogen absorption reaction, the initial rates method is used. The PCT absorption isotherms are measured at temperatures of 313, 333, and 353 K. The experimental data are described with quite high confidence by the chosen model, which assumes that the reaction rate controlling step is the dissociative absorption of hydrogen on the surface of the a-phase. The rate of hydrogen absorption increases with increasing pressure drop and temperature. It is shown that the rate of hydrogen absorption by the sample of pure IMC is significantly less dependent on temperature compared to the compact sample. In addition, the reaction rate at temperatures of 313 and 333 K is higher for the free backfill sample, and at 353 K it is higher for the metal hydride compact. The values of the absorption constant and the activation energy of the hydrogen absorption reaction are determined for both samples.

Kinetics of Hydrogen Absorption, Desorption And Permeation of Metals

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 34-38 ◽  
Author(s):  
T. G. OWE BERG
Keyword(s):  
Experimental Data ◽  
Reaction Mechanisms ◽  
Hydrogen Absorption ◽  
Hydrogen Gas ◽  
Acid Solutions ◽  
Dilute Acid ◽  
Energy Diffusion ◽  
Dissolved Hydrogen ◽  
Kinetics Of ◽  
Absorption Of Hydrogen

Abstract The reaction mechanisms for the absorption of hydrogen by metals from moist hydrogen gas and dilute acid solutions, for the desorption from metals of dissolved hydrogen in the presence of water and for hydrogen solubility and permeation under those conditions are discussed. Their kinetics are also given. Formulae are derived for rates and equilibria. These are compared with experimental data. The migration of H atoms in the metal is concluded to be associated with zero or nearly zero activation energy. Diffusion is rapid enough to maintain almost uniform distribution of H atoms in the metal during absorption and desorption under ordinary conditions. 3.8.4

scholarly journals Absorption of Hydrogen in the HBond©9000 Metal Hydride Tank

2018 ◽  
Vol 6 (11) ◽  
pp. 15-20
Author(s):  
Lukas Toth ◽  
Tomas Brestovic ◽  
Natalia Jasminska
Keyword(s):  
Specific Heat ◽  
Present Article ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Release Kinetics ◽  
Hydrogen Desorption ◽  
Intermetallic Alloy ◽  
Gas Pressure ◽  
Hydrogen Release ◽  
Absorption Of Hydrogen

The present article describes the measurements of hydrogen absorbed into an intermetallic alloy. The process of hydrogen absorption into a metal hydride tank is accompanied with generating heat that must be removed during the process. If the tank is not cooled, the gas pressure rapidly increases and even with a small amount of the stored hydrogen the pressure exceeds the permissible value. By contrast, during hydrogen desorption it is required to supply the same amount of specific heat to avoid a significant decrease in pressure which would result in a decrease in hydrogen release kinetics.  

Kinetics of hydrogen absorption in a stirred metal hydride slurry

AIChE Journal ◽  
1986 ◽  
Vol 32 (11) ◽  
pp. 1821-1831 ◽  
Author(s):  
Yuanki Tung ◽  
E. W. Grohse ◽  
F. B. Hill
Keyword(s):  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Kinetics Of

A Kinetic Study of Acid Corrosion of Cadmium

CORROSION ◽  
1958 ◽  
Vol 14 (1) ◽  
pp. 31-32
Author(s):  
HENRY WEAVER ◽  
CECIL C. LYNCH
Keyword(s):  
Activation Energy ◽  
Dilute Hydrochloric Acid ◽  
Reaction Rate ◽  
Acid Corrosion ◽  
Rotational Velocity ◽  
Cylindrical Sample ◽  
Zero Order ◽  
Cadmium Metal ◽  
Kinetics Of ◽  
Rate Controlling Step

Abstract The kinetics of the reaction of dilute hydrochloric acid with cadmium metal, molded, electroplated on brass, and dipped on brass, have been investigated by means of calibrated conductance measurements. The effect of annealing molded cadmium samples was to reduce the corrosion rate. Changing the speed of spinning the cylindrical sample increased the rate with increase in rotational velocity, up to a constant value at high velocities. The reaction rate at three acid concentrations and at three temperatures were determined. The activation energy is small, between one and two kilocalories per mole of cadmium reacting. In all cases the reaction was zero order over 90 percent of the reaction process. The rate controlling step has been estimated as that of diffusion through the layer surrounding the cadmium surface. 3.8.4

Measurement and Simulation of Transient Phenomena in Metal Hydride Bed

2015 ◽  
Vol 816 ◽  
pp. 204-212
Author(s):  
Tomáš Brestovič ◽  
Natália Jasminská ◽  
Mária Čarnogurská ◽  
Marián Lázár
Keyword(s):  
Metal Hydride ◽  
Time Interval ◽  
Transient Phenomena ◽  
Key Points ◽  
Extreme Load ◽  
Safe Limits ◽  
Kinetics Of ◽  
Temperature Time ◽  
Stationary Heat Transfer ◽  
Absorption Of Hydrogen

The article analyses the measurement with increased absorption kinetics of hydrogen into the La0.85Ce0.15Ni5 alloy. Within a time interval of 180 s an amount of 0.142 kg (1.58 m3) of hydrogen was absorbed into 56 kg of alloy. The process of absorption was accompanied by an increased temperature of the bed. Therefore it was simultaneously cooled by a cooler using Peltier elements. The numerical calculation of non-stationary heat transfer within the bed was performed with a known amount of heat generated in the bed, known temperatures and flow rates. Simulation results allow us to determine temperature time paths at key points of the bed and give insight on the transient phenomena which occurs in the extreme load of the metal hydride (MH) bed. This allows establishing safe limits for the absorption of hydrogen into a particular alloy.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

A CHANGE IN MAGNETIC PROPERTIES OF Ho2Co7 INTERMETALLIC COMPOUND UPON HYDROGEN ABSORPTION

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-517-C2-518 ◽  
Author(s):  
A. Apostolov ◽  
L. Bozukov ◽  
N. Stanev ◽  
T. Mydlarz
Keyword(s):  
Magnetic Properties ◽  
Intermetallic Compound ◽  
Hydrogen Absorption

STUDYING THE KINETIC CHARACTERISTICS OF THE EXTRACTION OF ANTHOCYANINS FROM THE SQUEEZE OF KRASNOSTOP ZOLOTOVSKY

2020 ◽  
Author(s):  
M.A. Egyan ◽  
Keyword(s):  
Reaction Rate ◽  
Sugar Content ◽  
Extraction Process ◽  
Efficiency Coefficient ◽  
Kinetic Characteristics ◽  
Reaction Rate Constants ◽  
Solids Content ◽  
Kinetics Of ◽  
Process Speed

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.

Thermal Decomposition Kinetics of Glyphosate (GP) and its Metabolite Aminomethylphosphonic Acid (AMPA)

2019 ◽  
Author(s):  
Milad Narimani ◽  
Gabriel da Silva
Keyword(s):  
Thermal Decomposition ◽  
Reaction Rate ◽  
Decomposition Kinetics ◽  
Rate Theory ◽  
Thermal Decomposition Mechanism ◽  
Treatment Processes ◽  
Aminomethylphosphonic Acid ◽  
Reaction Rate Theory ◽  
Decomposition Chemistry ◽  
Kinetics Of

Glyphosate (GP) is a widely used herbicide worldwide, yet accumulation of GP and its main byproduct, aminomethylphosphonic acid (AMPA), in soil and water has raised concerns about its potential effects to human health. Thermal treatment processes are one option for decontaminating material containing GP and AMPA, yet the thermal decomposition chemistry of these compounds remains poorly understood. Here, we have revealed the thermal decomposition mechanism of GP and AMPA by applying computational chemistry and reaction rate theory methods. <br>

Sign in / Sign up

Export Citation Format

Share Document