scholarly journals Thermal decomposition kinetics of a coumarin based copolymer: Poly(3-benzoyl coumarin-7-yl-methacrylate:0.54-co-methyl methacrylate:0.46)

2019 ◽  
Vol 15 (2) ◽  
pp. 206-211
Author(s):  
Adnan Kurt ◽  
Ahmet Faruk Ayhan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Methyl Methacrylate ◽  
Heating Rate ◽  
Kinetic Equations ◽  
Three Dimensional ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Coumarin 7 ◽  
Copolymer Poly ◽  
Kinetics Of

In present study, thermal decomposition studies of a copolymer based the coumarin containing monomer 3-benzoyl coumarin-7-yl-methacrylate (BCMA) and methyl methacrylate [poly(BCMA:0.54-co-MMA:0.46)] were performed by thermogravimetric analysis (TGA). The temperature for maximum rate losses was increased from 384.81 °C to 407.45 °C with the increasing in heating rate from 5 °C/min to 20°C/min. The thermal decomposition activation energies of copolymer in the conversion range of 9% - 21% were resulted to be 212.98 kJ/mol and 210.30 kJ/mol by Kissinger’s and Flynn–Wall–Ozawa methods, respectively. The study of kinetic equations such as Coats-Redfern, Tang, Madhusudanan and Van-Krevelen methods exhibited that the thermal decomposition process of the studied copolymer was followed with a D3 mechanism, a three-dimensional diffusion type deceleration solid state mechanism, at the optimum heating rate of 20 °C/min.  

scholarly journals Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Heating Rates ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Rate Loss ◽  
Kinetics Of

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

scholarly journals Synthesis and characterization of a novel isocoumarin derived polymer and its thermal decomposition kinetics

2018 ◽  
Vol 37 (2) ◽  
Author(s):  
Adnan Kurt ◽  
Halil Ibrahim Avci ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Thermal Decomposition Mechanism ◽  
Diffusion Type ◽  
Positive Direction ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Nmr Techniques ◽  
Optimum Heating

A novel isocumarin derived polymer poly(2-(isocoumarin-3-yl)-2-oxoethyl methacrylate) poly(ICEMA) was synthesized by free radical polymerization. The spectral characterization was performed with FTIR and 1H,13C-NMR techniques. The glass transition temperature of poly(ICEMA) was measured to be 161.69 °C by DSC technique. The initial decomposition temperatures obtained from TGA showed a change in the positive direction from 256.59 °C to 286.10 °C as the heating rate increased to 20 °C/min. Thermal decomposition activation energies of poly(ICEMA) in the conversion range of 7% - 19% were found to be 136.12 kJ/mol and 134.83 kJ/mol by Flynn–Wall–Ozawa and Kissinger’s models, respectively. In addition, various integral models such as Coats-Redfern, Tang, Madhusudanan and Van-Krevelen models were used to determine the thermal decomposition mechanism of poly(2-(isocoumarin-3-yl)-2-oxoethyl methacrylate)which showed that it proceeded at the optimum heating rate of 5 ºC/min over the D1 one-dimensional diffusion type deceleration mechanism

Study on the Pyrolysis Kinetics of HCl-Pretreated Soybean Stalk

2014 ◽  
Vol 953-954 ◽  
pp. 261-266
Author(s):  
Dong Yu Chen ◽  
Yan Qing Hu ◽  
Qing Yu Liu
Keyword(s):  
Heating Rate ◽  
Temperature Increase ◽  
Loss Rate ◽  
High Efficiency ◽  
Three Dimensional ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Acid Washing ◽  
Shoulder Peak ◽  
Kinetics Of

To study the influences of the acid-washing on the characteristics of soybean stalk pyrolysis , and search the high-efficiency catalyst for biomass pyrolysis, pyrolysis experiments of soybean stalk pretreated by 0.1mol/L HCl acid solution were performed by nonisothermal thermogravimetric analysis (TGA) at five different heating rates. The results showed the pyrolysis process of HCl-washed soybean stalk can be separated into four stages (water loss, depolymeri-zation and vitrification, thermal decomposition, and carbonization). At the same heating rate, the maximum pyrolysis rate of HCl-washed is larger than untreated soybean stalk, but the corresponding temperature is higher. All the DTG (differential thermogravimetric) curveas appear a smaller shoulder peak respectively. With the heating rate increasing, the main pyrolysis zone of the TG (thermogravimetric) and DTG curves move to the high-temperature direction, and the maximum pyrolysis rate and its corresponding temperature increase too. HCl-wahsed makes the weight loss rate of the final temperature increase 5% approximately. The value area of activation energy of the main pyrolysis area is 140.19~174.59 kJ/mol calculated by the method of Ozawa. The Šatava method inferred the most possible mechanism function of HCl-wahsed soybean stalk is Zhuralev-Lesakin-Tempelman equation, which is three-dimensional diffusion.

scholarly journals Influence of Liming on Kinetics of Sewage Sludge Pyrolysis

2019 ◽  
Vol 26 (1) ◽  
pp. 175-188
Author(s):  
Paweł Stolarek ◽  
Stanisław Ledakowicz ◽  
Radosław Ślęzak
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Mass Loss ◽  
Kinetic Parameters ◽  
Heating Rate ◽  
Visual Analysis ◽  
Pyrolysis Kinetics ◽  
Exponential Factor ◽  
The Impact ◽  
Kinetics Of

Abstract Thermogravimetry (TG) is the fast and reliable method for characterization of thermal decomposition of any material and in particular to determine the kinetics of pyrolytic decomposition of sewage sludge. Two types of sewage sludge with and without addition of lime were investigated from kinetic point of view. For TG analysis samples of selected sewage sludge were heated under the inert atmosphere of argon with constant heating rate from 303 to 1273 K; the three heating rate β = 5, 10 and 20 K/min were chosen. The iso-conversion methods of Friedman and Ozawa-Flynn-Wall were employed for analysis of TG results. As the sewage sludge decomposition is very complex process it cannot be described by a simple stoichiometric equation, therefore the so called lumping of reactions in the selected temperature ranges were used with detailed principles arising from visual analysis of DTG curve. The deconvolution of DTG curves performed according to Fraser-Suzuki asymmetric profile allowed the identification of number of lumps and their contribution to the overall mass loss. So the decomposition of sewage sludge with lime addition could be described with five groups of reactions while the one without lime by means of six lumps. The thermal decomposition of sewage sludge was assumed to proceed according to the scheme of parallel concurrent independent reactions of n-th order. The values of the apparent activation energies at different constant values of conversion degrees were determined by the iso-conversion analysis. To estimate the kinetic parameters the non-linear regression with Levenberg-Marquart optimization procedure was used. The kinetic parameters such as activation energy, pre-exponential factor, reaction order and fraction of total mass loss associated with a given reaction were determined. The impact of sewage sludge liming revealed in essential differences of pyrolysis products and pyrolysis kinetics of limed sludge and without lime one was highlighted.

Thermal decomposition kinetics of strontium oxalate

2007 ◽  
Vol 61 (5) ◽  
Author(s):  
F. Al-Newaiser ◽  
S. Al-Thabaiti ◽  
A. Al-Youbi ◽  
A. Obaid ◽  
M. Gabal
Keyword(s):  
Thermal Decomposition ◽  
Hexagonal Phase ◽  
Three Dimensional ◽  
Activation Parameters ◽  
Strontium Carbonate ◽  
Isothermal Tg ◽  
Diffusion Controlled ◽  
Reaction Models ◽  
Decomposition Behavior ◽  
Kinetics Of

AbstractThe thermal decomposition behavior in air of SrC2O4 · 1.25H2O was studied up to the formation of SrO using DTA-TG-DTG techniques. The decomposition proceeds through four well-defined steps. The first two steps are attributed to the dehydration of the salt, while the third and fourth ones are assigned to the decomposition of the anhydrous strontium oxalate into SrCO3 and the decomposition of SrCO3 to SrO, respectively. The exothermic DTA peak found at around 300°C is ascribed to the recrystallization of the anhydrous strontium oxalate. On the other hand, the endothermic DTA peak observed at 910°C can be attributed to the transition of orthorhombic-hexagonal phase of SrCO3. The kinetics of the thermal decomposition of anhydrous strontium oxalate and strontium carbonate, which are formed as stable intermediates, have been studied using non-isothermal TG technique. Analysis of kinetic data was carried out assuming various solid-state reaction models and applying three different computational methods. The data analysis according to the composite method showed that the anhydrous oxalate decomposition is best described by the two-dimensional diffusion-controlled mechanism (D2), while the decomposition of strontium carbonate is best fitted by means of the three-dimensional phase boundary-controlled mechanism (R3). The values of activation parameters obtained using different methods were compared and discussed.

Kinetics of Thermal Decomposition of Lime Stone

1967 ◽  
Vol 53 (7) ◽  
pp. 740-743 ◽  
Author(s):  
Kiyoshi SAWAMURA ◽  
Kazuichi MIZOGUCHI ◽  
Tetsuro HANADA ◽  
Kunihiko MAKINO
Keyword(s):  
Thermal Decomposition ◽  
Kinetics Of Thermal Decomposition ◽  
Kinetics Of ◽  
Lime Stone

Thermal Decomposition Kinetics of Torrefied Oil Palm Empty Fruit Bunch Briquettes

2016 ◽  
Vol 10 (3) ◽  
pp. 325-328 ◽  
Author(s):  
Bemgba Nyakuma ◽  
◽  
Arshad Ahmad ◽  
Anwar Johari ◽  
Tuan Abdullah ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Oil Palm ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetic Properties ◽  
Tg Analysis ◽  
Empty Fruit Bunches ◽  
Thermal Lag ◽  
Profile Characteristics ◽  
Kinetics Of

The study is aimed at investigating the thermal behavior and decomposition kinetics of torrefied oil palm empty fruit bunches (OPEFB) briquettes using a thermogravimetric (TG) analysis and the Coats-Redfern model. The results revealed that thermal decomposition kinetics of OPEFB and torrefied OPEFB briquettes is significantly influenced by the severity of torrefaction temperature. Furthermore, the temperature profile characteristics; Tonset, Tpeak, and Tend increased consistently due to the thermal lag observed during TG analysis. In addition, the torrefied OPEFB briquettes were observed to possess superior thermal and kinetic properties over the untorrefied OPEFB briquettes. It can be inferred that torrefaction improves the fuel properties of pelletized OPEFB for potential utilization in bioenergy conversion systems.

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