scholarly journals Determination of Kinetic Parameters for the Thermal Decomposition of Parthenium hysterophorus

2018 ◽  
Vol 22 (1) ◽  
pp. 5-21 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Suraj B. Singh ◽  
Muammel M. Hanon ◽  
Rekha Rawat
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Model Fitting ◽  
Frequency Factor ◽  
Heating Rates ◽  
Model Free ◽  
Higher Temperature ◽  
Good Agreement ◽  
Maximum Weight Loss

Abstract A kinetic study of pyrolysis process of Parthenium hysterophorous is carried out by using thermogravimetric analysis (TGA) equipment. The present study investigates the thermal degradation and determination of the kinetic parameters such as activation E and the frequency factor A using model-free methods given by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger, and model-fitting (Coats Redfern). The results derived from thermal decomposition process demarcate decomposition of Parthenium hysterophorous among the three main stages, such as dehydration, active and passive pyrolysis. It is shown through DTG thermograms that the increase in the heating rate caused temperature peaks at maximum weight loss rate to shift towards higher temperature regime. The results are compared with Coats Redfern (Integral method) and experimental results have shown that values of kinetic parameters obtained from model-free methods are in good agreement. Whereas the results obtained through Coats Redfern model at different heating rates are not promising, however, the diffusion models provided the good fitting with the experimental data.

scholarly journals Thermal decomposition of potassium titanium oxalate

2011 ◽  
Vol 76 (7) ◽  
pp. 1015-1026 ◽  
Author(s):  
Karuvanthodi Muraleedharan ◽  
Labeeb Pasha
Keyword(s):  
Carbon Dioxide ◽  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Model Fitting ◽  
Nitrogen Atmosphere ◽  
Single Step ◽  
Heating Rates ◽  
Decomposition Stage ◽  
Model Free ◽  
Good Agreement

The thermal decomposition of potassium titanium oxalate (PTO) was studied using non-isothermal thermogravimetry at different heating rates under a nitrogen atmosphere. The thermal decomposition of PTO proceeds mainly through five stages forming potassium titanate. The theoretical and experimental mass loss data are in good agreement for all stages of the thermal decomposition of PTO. The third thermal decomposition stage of PTO, the combined elimination of carbon monoxide and carbon dioxide, were subjected to kinetic analyses both by the method of model fitting and by the model free approach, which is based on the isoconversional principle. The model free analyses showed that the combined elimination of carbon monoxide and carbon dioxide and formation of final titanate in the thermal decomposition of PTO proceeds through a single step with an activation energy value of about 315 kJ mol-1.

scholarly journals Thermo-kinetics of Forest Waste Using Model-Free Methods

2019 ◽  
Vol 24 (1) ◽  
pp. 1-31 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Abdulrahman Th Mohammad ◽  
Toth Laszlo
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Isoconversional Methods ◽  
Pine Needles ◽  
Kissinger Method ◽  
Heating Rates ◽  
Pinus Roxburghii ◽  
Kinetics Parameters ◽  
Model Free

Thermal behaviour of pine needles (Pinus Roxburghii) is examined through a thermogravimetry technique. The dried samples of pine needles undergo the non isothermal decomposition at temperature range of 308 - 1173 K. The heating rates used for experimental purposes are: 5 °C min-1, 10 °C min-1 and 15 °C min-1. Kinetic parameters of thermal decomposition reactions of pine needles are obtained through the model-free schemes. The estimated values of activation energy and frequency factor derived from Kissinger method are 132.77 kJ mol-1 and 13.15 x107 min-1, respectively. Furthermore, the averaged values of the same kinetics parameters retrieved from the isoconversional methods are 82.38 kJ mol-1 and 74.833 kJ mol-1, 25.42 x1013 min-1 and 13.449 x1010 min-1, respectively. Instead of the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira Sunrose (KAS) schemes, the kinetic parameters derived from the Kissinger method are relatively promising for the thermal decomposition process, since the kinetic parameters are highly affected by intermediate stages and overlapping of the concurrent reaction occurred during pyrolysis.

scholarly journals Pyrolysis of Low Density Polyethylene: Kinetic Study Using TGA Data and ANN Prediction

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 891 ◽  
Author(s):  
Ibrahim Dubdub ◽  
Mohammed Al-Yaari
Keyword(s):  
Kinetic Parameters ◽  
Transfer Functions ◽  
Model Fitting ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Ann Model ◽  
Heating Rates ◽  
Highly Efficient ◽  
Model Free ◽  
Good Agreement

Pyrolysis of waste low-density polyethylene (LDPE) is considered to be a highly efficient, promising treatment method. This work aims to investigate the kinetics of LDPE pyrolysis using three model-free methods (Friedman, Flynn-Wall-Qzawa (FWO), and Kissinger-Akahira-Sunose (KAS)), two model-fitting methods (Arrhenius and Coats-Redfern), as well as to develop, for the first time, a highly efficient artificial neural network (ANN) model to predict the kinetic parameters of LDPE pyrolysis. Thermogravimetric (TG) and derivative thermogravimetric (DTG) thermograms at 5, 10, 20 and 40 K min−1 showed only a single pyrolysis zone, implying a single reaction. The values of the kinetic parameters (E and A) of LDPE pyrolysis have been calculated at different conversions by three model-free methods and the average values of the obtained activation energies are in good agreement and ranging between 193 and 195 kJ mol−1. In addition, these kinetic parameters at different heating rates have been calculated using Arrhenius and Coats-Redfern methods. Moreover, a feed-forward ANN with backpropagation model, with 10 neurons in two hidden layers and logsig-logsig transfer functions, has been employed to predict the thermogravimetric analysis (TGA) kinetic data. Results showed good agreement between the ANN-predicted and experimental data (R > 0.9999). Then, the selected network topology was tested for extra new input data with a highly efficient performance.

scholarly journals Synthesis, characterization and thermal decomposition of ethyl-2’-amino-5’-cyano-6’-(1H-indole-3yl)-2-oxospiro[indoline-3,4’-pyran]-3’-carboxylate under non‐isothermal condition in nitrogen atmosphere

2019 ◽  
Vol 10 (1) ◽  
pp. 72-81
Author(s):  
Ganesan Nalini ◽  
Natesan Jayachandramani ◽  
Radhakrishnan Suresh ◽  
Prakasam Thirumurugan ◽  
Venugopal Thanikachalam ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Model Fitting ◽  
Isothermal Condition ◽  
Nitrogen Atmosphere ◽  
Single Step ◽  
Heating Rates ◽  
Model Free ◽  
Ft Ir ◽  
Step Mechanism

A new compound, spiro-oxindole derivative compound namely ethyl-2ʹ-amino-5ʹ-cyano-6ʹ-(1H-indole-3yl)-2-oxospiro[indoline-3,4ʹ-pyran]-3ʹ-carboxylate (EACIOIPC) has been synthesized and characterized by microanalysis, FT-IR, mass spectrum and NMR (1H and 13C) techniques. The thermal decomposition of the compound was studied by thermogravimetric analysis under dynamic nitrogen atmosphere at different heating rates of 10, 15, 20 and 30 K/min. The kinetic parameters were calculated using model-free (Friedman’s, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods) and model-fitting (Coats and Redfern (CR)) methods. The decomposition process of EACIOIPC followed a single step mechanism as evidenced from the data. Existence of compensation effect is noticed for the decomposition of EACIOIPC. Invariant kinetic parameters are consistent with the average values obtained by Friedman and KAS in conversional methods.

scholarly journals Kinetic Analysis of the Thermal Decomposition of Polymer-Bonded Explosive Based on PETN: Model-Fitting Method and Isoconversional Method

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Trung Toan Nguyen ◽  
Duc Nhan Phan ◽  
Van Thom Do ◽  
Hoang Nam Nguyen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Model Fitting ◽  
Isoconversional Method ◽  
Isothermal Tg ◽  
Decomposition Reactions ◽  
Model Free ◽  
Negative Effect ◽  
Adverse Influence ◽  
Vacuum Stability Test

This work investigates kinetics and thermal decomposition behaviors of pentaerythritol tetranitrate (PETN) and two polymer-bonded explosive (PBX) samples created from PETN (named as PBX-PN-85 and PBX-PP-85) using the vacuum stability test (VST) and thermogravimetry (TG/DTG) techniques. Both model-free (isoconversional) and model-fitting methods were applied to determine the kinetic parameters of the thermal decomposition. It was found that kinetic parameters obtained by the modified Kissinger–Akahira–Sunose method (using non-isothermal TG/DTG data) were close to those obtained by the isoconversional and model-fitting methods that use isothermal VST data. The activation energy values of thermal decomposition reactions were 125.6–137.1, 137.3–144.9, and 143.9–152.4 kJ·mol−1 for PBX-PN-85, PETN, and PBX-PP-85, respectively. The results demonstrate the negative effect of the nitrocellulose-based binder in reducing the thermal stability of single PETN, while the polystyrene-based binder seemingly shows no adverse influence on the thermal decomposition of PETN in our presented PBX compositions.

scholarly journals Calculation of Kinetic Parameters of the Thermal Decomposition of Residual Waste of Coniferous Species: Cedrus Deodara

2018 ◽  
Vol 21 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Muammel M. Hanon
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Inert Atmosphere ◽  
Kissinger Method ◽  
Heating Rates ◽  
Cedrus Deodara ◽  
Coniferous Species ◽  
Competitive Reactions

Abstract This paper deals with pyrolysis decomposition of Cedrus deodara leaves with the help of thermogravimetric analysis (TGA). Experiments are performed in the presence of inert atmosphere of nitrogen. Experiments are conducted at three different heating rates of 5 °C∙min-1, 10 °C∙min-1 and 15 °C∙min-1 within temperature range of 35 °C to 700 °C. Arrhenius parameters such as activation energy and frequency factor are estimated by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger. The activation energy and frequency factor calculated by using Kissinger method are 67.63 kJ∙mol-1 and 15.06 . 104 min-1 respectively; whereas the averaged values of the same parameters through FWO and KAS methods are 89.59 kJ∙mol-1 and 84.748 kJ∙mol-1, 17.27 . 108 min-1 and 62.13 . 107 min-1 respectively. Results obtained through Kissinger method represent the actual values of kinetic parameters. Conversely, FWO and KAS methods reflect the apparent values of kinetic parameters, as they are highly influenced by the overlapping of competitive reactions occur during pyrolysis.

scholarly journals Kinetics of the thermal decomposition of pine needles

2015 ◽  
Vol 7 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Jitendra Gangwar
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Pine Needles ◽  
Experimental Results ◽  
Pyrolysis Process ◽  
Order Model ◽  
Exponential Factor ◽  
First Order ◽  
Model Free ◽  
Good Agreement

Abstract A kinetic study of the pyrolysis process of pine needles was examined using a thermogravimetric analyser. The weight loss was measured in nitrogen atmosphere at a purge flow rate of 100 ml/min. The samples were heated over a range of temperature of 19°C–600°C with a heating rate of 10°C/min. The results obtained from the thermal decomposition process indicate that there are three main stages: dehydration, active and passive pyrolysis. The kinetic parameters for the different samples, such as activation energy and pre-exponential factor, are obtained by the shrinking core model (reaction-controlled regime), the model-free, and the first-order model. Experimental results showed that the shrinking model is in good agreement and can be successfully used to understand degradation mechanism of loose biomass. The result obtained from the reaction-controlled regime represented actual values of kinetic parameters which are the same for the whole pyrolysis process; whereas the model-free method presented apparent values of kinetic parameters, as they are dependent on the unknown function ϕ(C), on the sum of the parameters of the physical processes, and on the chemical reactions that happen simultaneously during pyrolysis. Experimental results showed that values of kinetic constant from the first-order model and the SCM are in good agreement and can be successfully used to understand the behaviour of loose biomass (pine needles) in the presence of inert atmosphere. Using TGA results, the simulating pyrolysis can be done, with the help of computer software, to achieve a comprehensive detail of the devolatilization process of different types of biomasses.

Thermal degradation kinetics and lifetime of HDPE/PLLA/pro-oxidant blends

2016 ◽  
Vol 36 (9) ◽  
pp. 917-931 ◽  
Author(s):  
Gaurav Madhu ◽  
Dev K. Mandal ◽  
Haripada Bhunia ◽  
Pramod K. Bajpai
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Model Fitting ◽  
Frequency Factor ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Model Free ◽  
Calculation Technique ◽  
Thermal Degradation Behavior

Abstract The effect of adding poly(L-lactic acid) (PLLA) with and without a pro-oxidant additive cobalt stearate (CoSt) and compatibilizer maleic anhydride grafted polyethylene (MA-g-PE) on the thermal degradation and stability of high-density polyethylene (HDPE) films was analyzed using thermogravimetric analysis (TGA). The kinetic parameters [i.e. activation energy (Ea), order of reaction (n), and frequency factor ln(A)] of the samples were studied over a temperature range of 25°C–600°C at four heating rates (i.e. 5, 10, 15, and 20°C/min) through model-free techniques (e.g. Friedman, second Kissinger, and Flynn-Wall-Ozawa) and model-fitting techniques (e.g. Freeman-Carroll and Kim-Park). The value of Ea for neat HDPE was found to be much higher than PLLA; for the HDPE/PLLA blend, it was nearer to that of HDPE. An increase in the activation energy of 80/20 (HDPE/PLLA) blend was noticed by the addition of MA-g-PE. The TGA data and degradation kinetics were also used to predict the lifetime of the film samples. The lifetime of HDPE was found to decrease with the increase in the concentration of CoSt, thereby revealing its pro-oxidative ability. Minimum lifetime was noted for the HDPE/PLLA (80/20) sample blended with CoSt, which increased slightly in the presence of MA-g-PE. Studies indicated that the thermal degradation behavior and lifetime of the investigated film samples depends not only on the fractions of their constituents but also on the heating rates and calculation technique.

Synthesis and Kinetic Study by Ozawa Method of the Thermal Decomposition of Complexes Ln(thd)3phen

2006 ◽  
Vol 530-531 ◽  
pp. 513-519 ◽  
Author(s):  
Wilton Silva Lopes ◽  
Crislene Rodrigues da Silva Morais ◽  
A.G. de Souza
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Decomposition Kinetics ◽  
Quantum Yields ◽  
Molecular Devices ◽  
Ozawa Method ◽  
Mixed Ligands ◽  
Spectroscopic Characteristics

Recently, highly luminescent lanthanide complexes with mixed ligands such as and β-diketone and two herobiaryl ligands have been synthesized and suggested as promising light-conversion molecular devices as described by several authors. The synthesis, luminescence, quantum yields, spectroscopic characteristics, structure, among others properties of these complexes, including the possibility of production thin film films from these materials have been discussed, but little is known about their thermal decomposition kinetics. In this work we report the determination of kinetic parameters of thermal decomposition of the complexes Gd(thd)3phen and Er(thd)3phen (thd=2,2,6,6-tetramethyl-3,5- heptanodione; phen=1,10-phenantroline) using the method proposed by Ozawa (1965). The kinetic parameters obtained for activation energy were: 90 and 87 kJ.mol-1, the values of frequency factor were: 2.3x107 and 2.0x107 s-1 for Gd(thd)3phen and Er(thd)3phen, respectively. On the kinetic energy of the complexes, we notice the following order in thermal stability: Gd(thd)3phen < Er(thd)3phen.

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