Kinetics of hydrogen reduction of ferrous oxide in a batch fluidized bed: Effects of mass velocity and pressure

AIChE Journal ◽  
1964 ◽  
Vol 10 (5) ◽  
pp. 652-655 ◽  
Author(s):  
W. D. Ahner ◽  
Jerome Feinman
Keyword(s):  
Fluidized Bed ◽  
Mass Velocity ◽  
Hydrogen Reduction ◽  
Ferrous Oxide ◽  
Kinetics Of

Kinetics of hydrogen reduction of Brazilian hematite in a micro-fluidized bed

2021 ◽  
Vol 46 (5) ◽  
pp. 4592-4605
Author(s):  
Kun He ◽  
Zhong Zheng ◽  
Zhiwei Chen ◽  
Hongsheng Chen ◽  
Weiping Hao
Keyword(s):  
Fluidized Bed ◽  
Hydrogen Reduction ◽  
Kinetics Of

The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

1993 ◽  
Vol 28 (2) ◽  
pp. 135-144 ◽  
Author(s):  
S. Matsui ◽  
R. Ikemoto Yamamoto ◽  
Y. Tsuchiya ◽  
B. Inanc
Keyword(s):  
Sulfate Reduction ◽  
Fluidized Bed ◽  
Kinetic Equations ◽  
Fluidized Bed Reactor ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Glucose Decomposition ◽  
Reaction Equations ◽  
Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

scholarly journals The influence of an external magnetic field on the dynamics of magnetite reduction with hydrogen

RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15422-15427
Author(s):  
Petr A. Chernavsky ◽  
Nellie V. Kim ◽  
Victor A. Andrianov ◽  
Yurii D. Perfiliev ◽  
Alla A. Novakova ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Hydrogen Reduction ◽  
Kinetics Of

The kinetics of hydrogen reduction of magnetite was investigated in different magnetic fields.

Kinetics of hydrogen reduction of the Fe-Co-O system

1983 ◽  
Vol 22 (7) ◽  
pp. 516-518
Author(s):  
E. V. Ishchenko ◽  
I. V. Uvarova ◽  
V. K. Yatsimirskii
Keyword(s):  
Hydrogen Reduction ◽  
Kinetics Of

scholarly journals The Kinetics of Isothermal Hydrogen Reduction of Nanocrystalline Fe2O3 Powder

2014 ◽  
Vol 55 (10) ◽  
pp. 1611-1617 ◽  
Author(s):  
Geon-Yong Lee ◽  
Joon-Phil Choi ◽  
Jun-Il Song ◽  
Sung-Soo Jung ◽  
Jai-Sung Lee
Keyword(s):  
Hydrogen Reduction ◽  
Kinetics Of

Kinetics of synthesizing process for obtaining iron nanopowder by chemical-metallurgical method under isothermal conditions

2021 ◽  
pp. 72-77
Author(s):  
Tien Hiep Nguyen ◽  
◽  
Van Minh Nguyen ◽  
Keyword(s):  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Reduction Process ◽  
Nitrogen Adsorption ◽  
Specific Rate ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

In this work the kinetics of synthesizing process of metallic iron nanopowder by hydrogen reduction from α-FeOOH hydroxide under isothermal conditions were studied. α-FeOOH nanopowder was prepared in advance by chemical deposition from aqueous solutions of iron nitrate Fe(NO3)3 (10 wt. %) and alkali NaOH (10 wt. %) at room temperature, pH = 11, under the condition of continuous stirring. The hydrogen reduction process of α-FeOOH nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 390 to 470 °C. The study of the crystal structure and composition of the powders was performed by X-ray phase analysis. The specific surface area S of the samples was measured using BET method by low-temperature nitrogen adsorption. The average particle size D of powders was determined via the measured S value. The size characteristics and morphology of the particles were investigated by transmission and scanning electron microscopes. The calculation of the kinetic parameters of the hydrogen reduction process of α-FeOOH under isothermal conditions was carried out by the Gray-Weddington model and Arrhenius equation. It is shown that the rate constant of reduction at 470 °C is approximately 2.2 times higher than in the case at 390 °C. The effective activation energy of synthesizing process of iron nanopowder by hydrogen reduction from α-FeOOH was ~38 kJ/mol, which indicates a mixed reaction mode. In this case, the kinetics overall process is limited by both the kinetics of the chemical reaction and the kinetics of diffusion, respectively, an expedient way to accelerate the process by increasing the temperature or eliminate the diffusion layer of the reduction product by intensive mixing. It is show that Fe nanoparticles obtained by hydrogen reduction of its hydroxide at 410 °C, corresponding to the maximum specific rate of the reduction process, are mainly irregular in shape, evenly distributed, the size of which ranges from several dozens to 100 nm with an average value of 75 nm.

Study on the kinetics of process for obtaining cobalt nanopowder by hydrogen reduction under isothermal conditions

2021 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Hieр Nguyen Tien
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

The kinetics of metallic cobalt nanopowder synthesizing by hydrogen reduction from Co(OH)2 nanopowder under isothermal conditions were studied. Co(OH)2 nanopowder was prepared in advance by chemical deposition from aqueous solutions of Co(NO3)2 cobalt nitrate (10 wt.%) and NaOH alkali (10 wt.%) at room temperature, pH = 9 under continuous stirring. The hydrogen reduction of Co(OH)2 nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 270 to 310 °C. The crystal structure and composition of powders was studied by X-ray phase analysis. The specific surface area of samples was measured using the BET method by low-temperature nitrogen adsorption. The average particle size of powders was determined by the measured specific surface area. Particles size characteristics and morphology were investigated by transmission and scanning electron microscopes. Kinetic parameters of Co(OH)2 hydrogen reduction under isothermal conditions were calculated using the Gray–Weddington model and Arrhenius equation. It was found that the rate constant of reduction at t = 310 °C is approximately 1.93 times higher than at 270 °C, so the process accelerates by 1.58 times for 40 min of reduction. The activation energy of cobalt nanopowder synthesizing from Co(OH)2 by hydrogen reduction is ~40 kJ/mol, which indicates a mixed reaction mode. It was shown that cobalt nanoparticles obtained by the hydrogen reduction of its hydroxide at 280 °C are aggregates of equiaxed particles up to 100 nm in size where individual particles are connected to several neighboring particles by contact isthmuses.

Effects of Hydrogen and Temperature on the Kinetics of the Fluidized-Bed Nitridation of Silicon

1994 ◽  
Vol 77 (1) ◽  
pp. 186-192 ◽  
Author(s):  
Zoran Jovanovic ◽  
Shoichi Kimura ◽  
Octave Levenspiel
Keyword(s):  
Fluidized Bed ◽  
Kinetics Of
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