An advanced reaction model determination methodology in solid-state kinetics based on Arrhenius parameters variation

Shahcheraghi, Seyed Hadi; Khayati, Gholam Reza; Ranjbar, Mohammad

doi:10.1007/s10973-015-4708-8

Cited by 28 publications

(13 citation statements)

References 56 publications

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“…In solid-state reactions, appropriate kinetic equations, rate limiting steps, and calculation of kinetic parameters could supply a deeper conception into the possible transformation mechanisms [30]. Determination of the most probable reaction mechanism model(s) can be complicated for multi-step reaction kinetics [31]. The DTA and TG curves of non-isothermal decomposition of the investigated sulfide copper concentrate at four different heating rates (5,10,15, and 20 °C min -1 ) are shown in Fig.…”

Section: Kinetic Analysis Resultsmentioning

confidence: 99%

Reaction mechanism and kinetics of sulfide copper concentrate oxidation at elevated temperatures

et al. 2017

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Sulfide copper concentrate from domestic ore deposit (Bor, Serbia) was subjected to oxidation in the air atmosphere due to a better understanding of reaction mechanism and oxidation of various sulfides present in the copper concentrate at elevated temperatures. Results of the initial sample characterization showed that concentrate is chalcopyrite-enargite-tennantite type, with an increased arsenic content. Characterization of the oxidation products showed the presence of sulfates, oxysulfates, and oxides. Based on predominance area diagrams for Me-S-O systems (Me = Cu, Fe, As) combined with thermal analysis results, the reaction mechanism of the oxidation process was proposed. The reactions which occur in the temperature range 25 -1000 °C indicate that sulfides are unstable in the oxidative conditions. Sulfides from the initial sample decomposed into binary copper and iron sulfides and volatile arsenic oxides at lower temperatures. Further heating led to oxidation of sulfides into iron oxides and copper sulfates and oxysulfates. At higher temperatures sulfates and oxysulfates decomposed into oxides. Kinetic analysis of the oxidation process was done using Ozawa's method in the non-isothermal conditions. The values for activation energies showed that the reactions are chemically controlled and the temperature is the most influential parameter on the reaction rates.

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Section: Kinetic Analysis Resultsmentioning

confidence: 99%

Reaction mechanism and kinetics of sulfide copper concentrate oxidation at elevated temperatures

et al. 2017

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“…If the kinetic model can reflect the solid pyrolysis process appropriately, there is a linear relationship between ln( g ( α )) versus ln β , and the slope should be close to −1, and the linear correlation coefficient R 2 is higher [ 47 ]. The P ( x ) applies to the approximation of Equation (9).…”

Section: Methodsmentioning

confidence: 99%

Pyrolysis Kinetic Properties of Thermal Insulation Waste Extruded Polystyrene by Multiple Thermal Analysis Methods

Zhang

et al. 2020

Materials

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Extruded polystyrene (XPS) is a thermal insulation material extensively applied in building systems. It has attracted much attention because of outstanding thermal insulation performance, obvious flammability shortcoming and potential energy utilization. To establish the reaction mechanism of XPS’s pyrolysis, thermogravimetric experiments were performed at different heating rates in nitrogen, and multiple methods were employed to analyze the major kinetics of pyrolysis. More accurate kinetic parameters of XPS were estimated by four common model-free methods. Then, three model-fitting methods (including the Coats-Redfern, the iterative procedure and masterplots method) were used to establish the kinetic model. Since the kinetic models established by the above three model-fitting methods were not completely consistent based on different approximations, considering the effect of different approximates on the model, the reaction mechanism was further established by comparing the conversion rate based on the model-fitting methods corresponding to the possible reaction mechanisms. Finally, the accuracy of the above model-fitting methods and Particle Swarm Optimization (PSO) algorithm were compared. Results showed that the reaction function g(α) = (1 − α)−1 − 1 might be the most suitable to characterize the pyrolysis of XPS. The conversion rate calculated by masterplots and PSO methods could provide the best agreement with the experimental data.

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“…Various methods have been proposed over the last few years to estimate the reaction model. The detailed explanation of these different methods can be found elsewhere . In this research work, a recently developed regression method was used .…”

Section: Theoreticalmentioning

confidence: 99%

“…The detailed explanation of these different methods can be found elsewhere. [29][30][31][32][33] In this research work, a recently developed regression method was used. [27] The method utilizes the Šesták-Berggren (SB) equation to develop Equation (10).…”

Section: Reaction Modelmentioning

confidence: 99%

Investigation on the Thermal Degradation Kinetics of Polypropylene/Organically Modified Montmorillonite Nanocomposites with Different Levels of Compatibilizer

Vimalathithan

Barile

Casavola

et al. 2018

Macro Materials & Eng

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Polypropylene/organically modified montmorillonite (OMMT) nanocomposites are prepared with different levels of compatibilizer (maleic anhydride functionalized polypropylene) and OMMT. A specially designed polymer nanocomposite injection molding compounder with a hyperbolic nozzle is used to prepare the nanocomposites. The thermal kinetic parameters, the activation energy, pre‐exponential factor, and the reaction model are estimated using isoconversional methods. The activation energy of virgin polypropylene is slightly higher than the polypropylene/OMMT nanocomposites. However, the presence of the compatibilizer is the vital reason for the lower activation energy in the polypropylene/OMMT nanocomposites. The reaction model explains the complexity of the reaction in the presence of OMMT and its influence on the accelerated charring in the later stages of degradation. The optimum working temperature of the prepared polypropylene/clay nanocomposites is significantly higher thus proving that OMMT improves the thermal stability of the nanocomposites. The polypropylene with 5% OMMT and 10% compatibilizer in its weight proportion has the optimum working temperature of 198 °C for 20 000 h before losing its integrity.

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An advanced reaction model determination methodology in solid-state kinetics based on Arrhenius parameters variation

Cited by 28 publications

References 56 publications

Reaction mechanism and kinetics of sulfide copper concentrate oxidation at elevated temperatures

Reaction mechanism and kinetics of sulfide copper concentrate oxidation at elevated temperatures

Pyrolysis Kinetic Properties of Thermal Insulation Waste Extruded Polystyrene by Multiple Thermal Analysis Methods

Investigation on the Thermal Degradation Kinetics of Polypropylene/Organically Modified Montmorillonite Nanocomposites with Different Levels of Compatibilizer

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