Investigation of combustion kinetics of Umutbaca-lignite by thermal analysis technique

Naktiyok, Jale; Bayrakçeken, Hatice; Özer, A. Kadir; Gülaboğlu, M. Şahin

doi:10.1007/s10973-017-6149-z

Cited by 35 publications

(14 citation statements)

References 28 publications

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“…With increasing conversion, the activation energy of bituminous coal increased firstly and then decreased, and the activation energy of char linearly decreased. Naktiyok 8 used mode-free methods (FWO and KAS methods) and a model-fitting method (Coats–Redfern (C–R) method) to calculate the kinetic parameters of lignite, and the ideal reaction model was determined by the C–R method. Research suggests that the results of the two methods (FWO and KAS) are the same, and the most probable kinetic models used to describe lignite combustion are diffusion models (D 4 ) with the C–R method.…”

Section: Introductionmentioning

confidence: 99%

“…The experimental values of y(a) and/or z(a) can be determined for each value of a by the experimental values of E a , da/dt and T a under different heating rates. So, for each value of a under different heating rates, one needs to determine experimental values of E a , da/dt and T a related to this a and insert them into eqn (7) and (8). The resulting experimental values of y(a) and/or z(a) are plotted as a function of a and compared against theoretical y(a) and/or z(a) master plots to determine the most appropriate kinetic model.…”

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confidence: 99%

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Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Wang

Cheng

et al. 2018

RSC Adv.

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In this paper, the combustion reaction kinetics of pyrolysis char of low-rank coal is studied by thermal analysis technology. For the combustion process of the char at different heating rates, the reaction kinetic parameters were calculated by three common mode-free methods (FWO method, KAS method , respectively, and the activation energy decreased with increasing conversion rates. There is a compensation effect between the activation energy and pre-exponential factor of char combustion. Results of the kinetic analysis by Malek method and Popescu method both indicated that the Avrami-Erofeev equation) controlled by nucleation and nuclei growth models is the most probable reaction model of char combustion.

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Section: Introductionmentioning

confidence: 99%

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confidence: 99%

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Wang

Cheng

et al. 2018

RSC Adv.

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“…For graphical calculations of KAS, OFW and CR methods were used the following formulas according to the literature. For KAS calculations equation 1 [20][21][22][23][24][25][26][27][28][29], for OFW equation 2 [22][23][24][25][26][27][28][29][30][31][32] and for CR equation 3 [31][32][33][34] 5.…”

Section: Methodsmentioning

confidence: 99%

The Thermal Investigation, Thermokinetic Analysis and Antimicrobial Activity of Two New Energetic Materials Obtained from Nucleophilic Substitution of Nitro Pyridine Ring

İnal

Acar

Sopacı

et al. 2018

Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi

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2-Chloro-3 and 5-dinitropyridine were put into reaction with hydrazine and 3-aminopyrazole to obtain two new highly nitrogenous energetic substances. These energetic substances are; N(3,5-dinitropyridyn-2-yl) hydrazine (I), and N(3,5dinitropyridyn-2-yl)3-aminopyrazole (II). These substances were characterized with element analysis, mass spectroscopy, IR spectroscopy, 1 HNMR and 13 CNMR methods. Besides, the substances were analyzed with TG and thermal decomposition mechanisms were interpreted. Apart from these, isothermal and thermal kinetic analysis methods were used to reveal out the activation energies and Arrhenius pre-exponential factors. Thermodynamic parameters of decomposition reactions were measured by using these values. Nitrofuroxane ring was concluded to be the sub-product in thermal decomposition reactions. Gaussian 09 software algorithms were used to measure the standard formation enthalpy values of the two energetic substances. Using these values, the reaction enthalpy value of the thermal decomposition reaction according to Hess's law and the result obtained was compared with the value obtained from the differential scanning calorimetry method. Experimental and theoretical results were observed to be similar. In addition to these, antimicrobial effects of the highly nitrogenous energetic substances were measured for 5 different bacteria and their antifungal effects were measured for one type of fungus. As they were highly nitrogenous, the bacteria were found to be using the nitrogen in these substances for nutritional purpose.

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“…Besides, employing E a and A values, other thermodynamic parameters such as entropy (S), enthalpy (H) and Gibbs free energy (G) changes for the thermal decompositions were calculated. The entropy change in a thermal reaction can be approximated by using the pre-exponential factor 28 (Equations 5 and 6):…”

Section: Kinetic Analysismentioning

confidence: 99%

“…Then, the thermal decomposition of the compounds was examined by TG at different heating rates. The TG data obtained were used in the determination of activation energy (E a ) and pre-exponential factor A of the thermal decomposition reactions utilizing the nonisothermal-isoconvertional Ozawa-Flynn-Wall (OFW) [15][16][17][18][19][20][21][22][23] and Kissinger-Akahira-Sunose (KAS) [19][20][21][22][23][24][25][26] and isothermal Coats-Redfern (CR) [27][28][29] methods.…”

Section: Introductionmentioning

confidence: 99%

Some Nitrogen Rich Energetic Material Synthesis by Nucleophilic Substitution Reaction from Polynitro Aromatic Compounds

Gürpınar

Tuncer

Sopacı

et al. 2021

ACSi

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Three new nitrogen-rich energetic compounds, N-(5-chloro-2,4-dinitrophenyl)hydrazine (1), N-(5-chloro-2,4-dinitrophenyl) guanidine (2) and N-(5-chloro-2,4-dinitrophenyl)-4-aminopyrazole (3) prepared by the nucleophilic substitution reaction of 1,3-dichloro-4,6-dinitrobenzene with hydrazine, guanidinium carbonate and 4-aminopyrazole. The compounds were characterized by 1H NMR, 13C NMR, IR and mass spectroscopy. Only compound 2 could be prepared in a suitable crystal and molecular model was determined by X-ray analysis. Compounds were investigated by TG and DSC. Thermal degradation and thermokinetic behavior were investigated by Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose techniques. Compounds were observed to be prone to exothermical thermal decomposition. HOMO and LUMO levels, theoretical formation enthalpy and electrostatic maps were calculated by Gaussian09. The detonation velocity and pressure were calculated by Kamlet–Jacobs equation. The compounds were assayed for antimicrobial properties.

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Investigation of combustion kinetics of Umutbaca-lignite by thermal analysis technique

Cited by 35 publications

References 28 publications

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

The Thermal Investigation, Thermokinetic Analysis and Antimicrobial Activity of Two New Energetic Materials Obtained from Nucleophilic Substitution of Nitro Pyridine Ring

Some Nitrogen Rich Energetic Material Synthesis by Nucleophilic Substitution Reaction from Polynitro Aromatic Compounds

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