scholarly journals Mechanism of reaction of silica and carbon for producing silicon carbide

2019 ◽  
Vol 45 ◽  
pp. 146867831989141
Author(s):  
Bahador Abolpour ◽  
Rahim Shamsoddini
Keyword(s):  
Experimental Data ◽  
Silicon Carbide ◽  
Reaction Kinetics ◽  
Direct Effect ◽  
Solid Reaction ◽  
Carbon Reduction ◽  
Temperature Range ◽  
Carbon Particles ◽  
Mechanism Of Reaction ◽  
Kinetics Of

The reaction kinetics of carbon reduction of silica were investigated using thermodynamic concepts and by fitting to relevant models the experimental data obtained for this reduction using a thermogravimetric unit in the temperature range of 1566 to 1933 K. The results show that the only way to produce SiC in this reduction is the reaction of Si, SiO, or SiO2 at the surface or by diffusion of SiO inside the carbon particles while CO and CO2 have no direct effect on the process. The controlling step of this reduction at temperatures lower than 1750 K is the chemical gas–solid or solid–solid reaction at the surface of the carbon particles, while at higher temperatures, the rate of SiO diffusing inside the carbon particles controls the rate of this reduction.

Kinetic and Thermodynamic Aspects of the Bainite Reaction in a Silicon Steel

1983 ◽  
Vol 21 ◽  
Author(s):  
G. Papadimitriou ◽  
J.M.R. Genin
Keyword(s):  
Experimental Data ◽  
Silicon Carbide ◽  
Reaction Kinetics ◽  
Silicon Content ◽  
Silicon Steel ◽  
Tentative Model ◽  
Secondary Stage ◽  
Two Stages ◽  
Kinetics Of ◽  
And Diffusion

ABSTRACTThe bainite reaction in an Fe - 3.85 wt pct Si - 0.9 wt pct C steel is studied by several experimental techniques in the range of 250–450°C.The high silicon content prevents the formation of cementite, so that the reaction is separated to two clearly distinct stages. In the primary stage ferrite forms alone, except at temperatures lower than 310°C where some carbides precipitate in it, and austenite becomes enriched in carbon. In the secondary stage occurring only above 400°C, the enriched austenite decomposes to ferrite and an unknown silicon carbide.The microstructure, the enrichment of the austenite and the overall reaction kinetics of the two stages are studied and are found to be consistent with a displacive mechanism of the bainite reaction.A tentative model, accounting for the competition of shear and diffusion, is proposed in order to fit our experimental data.

Fast Gas-Solid Reaction Kinetics of Nanoparticles Unveiled by Millisecond In Situ Electron Diffraction at Ambient Pressure

2018 ◽  
Vol 57 (35) ◽  
pp. 11344-11348 ◽  
Author(s):  
Jian Yu ◽  
Wentao Yuan ◽  
Hangsheng Yang ◽  
Qiang Xu ◽  
Yong Wang ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Reaction Kinetics ◽  
Ambient Pressure ◽  
Solid Reaction ◽  
Kinetics Of ◽  
Gas Solid Reaction

scholarly journals Hydrothermal Carbonization Kinetics of Lignocellulosic Agro-Wastes: Experimental Data and Modeling

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 516 ◽  
Author(s):  
Michela Lucian ◽  
Maurizio Volpe ◽  
Luca Fiori
Keyword(s):  
Experimental Data ◽  
Reaction Kinetics ◽  
Reaction Pathway ◽  
Hydrothermal Carbonization ◽  
Kinetics Model ◽  
Transient Phase ◽  
Lumped Model ◽  
Gaseous Products ◽  
Best Fitting ◽  
Kinetics Of

Olive trimmings (OT) were used as feedstock for an in-depth experimental study on the reaction kinetics controlling hydrothermal carbonization (HTC). OT were hydrothermally carbonized for a residence time τ of up to 8 h at temperatures between 180 and 250 °C to systematically investigate the chemical and energy properties changes of hydrochars during HTC. Additional experiments at 120 and 150 °C at τ = 0 h were carried out to analyze the heat-up transient phase required to reach the HTC set-point temperature. Furthermore, an original HTC reaction kinetics model was developed. The HTC reaction pathway was described through a lumped model, in which biomass is converted into solid (distinguished between primary and secondary char), liquid, and gaseous products. The kinetics model, written in MATLABTM, was used in best fitting routines with HTC experimental data obtained using OT and two other agro-wastes previously tested: grape marc and Opuntia Ficus Indica. The HTC kinetics model effectively predicts carbon distribution among HTC products versus time with the thermal transient phase included; it represents an effective tool for R&D in the HTC field. Importantly, both modeling and experimental data suggest that already during the heat-up phase, biomass greatly carbonizes, in particular at the highest temperature tested of 250 °C.

General equations for the reaction kinetics of solids

1976 ◽  
Vol 29 (1) ◽  
pp. 27
Author(s):  
JH Taplin
Keyword(s):  
Experimental Data ◽  
Boundary Condition ◽  
Reaction Kinetics ◽  
Theoretical Basis ◽  
Reaction Equation ◽  
Kinetics Of

The index-of-reaction equation (i.r.e.): dF/dtZ = kZ(l - βF)m is compared with a generalized Prout-Tompkins equation (g.P.T.e.): dF/dt = kn(l - βF)y With the boundary condition F = 0, t = 0 the equations are equivalent for z = 2 or m = 0 or β ≤ 1 and the i.r.e, is closely approximated by the g.P.T.e. for other values of the parameters by use of the following approximation ∫(1- F)-m dF ≈ AF(1-BF)5 The parameter s is a function of m. Both A and B are close to unity for 1/3 < m < 3. The i.r.e. is recommended as being more useful than the g.P.T.e. because the i.r.e. has a better theoretical basis and because it is more readily integrated and fitted to experimental data.

scholarly journals A combined high-temperature experimental and theoretical kinetic study of the reaction of dimethyl carbonate with OH radicals

2017 ◽  
Vol 19 (10) ◽  
pp. 7147-7157 ◽  
Author(s):  
Fethi Khaled ◽  
Binod Raj Giri ◽  
Milán Szőri ◽  
Tam V.-T. Mai ◽  
Lam K. Huynh ◽  
...  
Keyword(s):  
High Temperature ◽  
Shock Waves ◽  
Kinetic Study ◽  
Reaction Kinetics ◽  
Dimethyl Carbonate ◽  
Oh Radicals ◽  
Temperature Range ◽  
Reflected Shock ◽  
Kinetics Of

The reaction kinetics of dimethyl carbonate (DMC) and OH radicals were investigated behind reflected shock waves over the temperature range of 872–1295 K and at pressures near 1.5 atm.

Oxidation kinetics of silicon carbide in steam at temperature range of 1400 to 1800 °C studied by laser heating

2020 ◽  
Vol 529 ◽  
pp. 151939 ◽  
Author(s):  
Hai Vu Pham ◽  
Yuji Nagae ◽  
Masaki Kurata ◽  
David Bottomley ◽  
Kenichiro Furumoto
Keyword(s):  
Silicon Carbide ◽  
Oxidation Kinetics ◽  
Laser Heating ◽  
Temperature Range ◽  
Kinetics Of

scholarly journals Anionic Polymerization of ε-Caprolactam under the Influence of Water: 2. Kinetic Model

2020 ◽  
Vol 4 (1) ◽  
pp. 8 ◽  
Author(s):  
Rainer Wendel ◽  
Philipp Rosenberg ◽  
Michael Wilhelm ◽  
Frank Henning
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Reaction Kinetics ◽  
Water Content ◽  
Anionic Polymerization ◽  
Polyamide 6 ◽  
External Influences ◽  
Influence Of Water ◽  
Kinetics Of

The reaction kinetics of anionic polymerization for the production of anionic polyamide 6 (aPA6) are widely understood. It is also known that this reaction is very sensitive to external influences such as water. This paper analyzes and quantifies the influence of water on the reaction of ε-caprolactam to anionic polyamide 6. A kinetic model is developed in which the reactive molecules of the activator and catalyst are defined as variables and the concentrations of activator and catalyst as well as water content are considered. A model for the calculation of the reaction kinetics is established and validated with experimental data. The developed model can be used to predict the influence and compensation of water by addition of surplus activator and catalyst during the polymerization of ε-caprolactam.

Sign in / Sign up

Export Citation Format

Share Document