The effects of sample size and heating rate on the kinetics of the thermal decomposition of CaCO3

1973 ◽  
Vol 6 (1) ◽  
pp. 67-83 ◽  
Author(s):  
P.K. Gallagher ◽  
D.W. Johnson
Keyword(s):  
Thermal Decomposition ◽  
Sample Size ◽  
Heating Rate ◽  
Kinetics Of

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 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.

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.  

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.

Thermal Decomposition Kinetics of Glyphosate (GP) and its Metabolite Aminomethylphosphonic Acid (AMPA)

2019 ◽  
Author(s):  
Milad Narimani ◽  
Gabriel da Silva
Keyword(s):  
Thermal Decomposition ◽  
Reaction Rate ◽  
Decomposition Kinetics ◽  
Rate Theory ◽  
Thermal Decomposition Mechanism ◽  
Treatment Processes ◽  
Aminomethylphosphonic Acid ◽  
Reaction Rate Theory ◽  
Decomposition Chemistry ◽  
Kinetics Of

Glyphosate (GP) is a widely used herbicide worldwide, yet accumulation of GP and its main byproduct, aminomethylphosphonic acid (AMPA), in soil and water has raised concerns about its potential effects to human health. Thermal treatment processes are one option for decontaminating material containing GP and AMPA, yet the thermal decomposition chemistry of these compounds remains poorly understood. Here, we have revealed the thermal decomposition mechanism of GP and AMPA by applying computational chemistry and reaction rate theory methods. <br>

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