Comparison of several kinetic approaches to evaluate the pyrolysis of three Mediterranean forest fuels

2011 ◽  
Vol 20 (3) ◽  
pp. 407 ◽  
Author(s):  
Virginie Tihay ◽  
Philippe Gillard
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Degree Of Conversion ◽  
Mediterranean Forest ◽  
Mass Rate ◽  
Forest Fuels ◽  
Fire Modelling ◽  
Friedman Method ◽  
Current Kinetic ◽  
Good Agreement

The thermal degradation of three Mediterranean forest fuels was studied by using thermogravimetric analysis. The different behaviours were compared and the degradation characteristics were determined for each fuel. Then a kinetic study was performed. Simple modelling of the thermal degradation was carried out with a global scheme. These results were compared with current kinetic models used in forest fire modelling. These methods predict the mass rate evolution globally. However, they do not describe the fluctuations well owing to the different pyrolysis steps. Next, the kinetic parameters were established in function of the degree of conversion with isoconversion methods for each fuel. The results calculated by the Friedman method were compared with the experimental results, showing good agreement. These data, which take into account the degree of conversion and the fuel, can be useful to model the burning rate of forest fuels.

Kinetic Study of PVC Pyrolysis in Air by Thermogravimetric Analysis Using the Friedman Method

2012 ◽  
Vol 427 ◽  
pp. 64-69 ◽  
Author(s):  
Bin Han ◽  
Yu Long Wu ◽  
Wei Feng ◽  
Zhen Chen ◽  
Ming De Yang
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Heating Rate ◽  
Inert Atmosphere ◽  
Nitrogen Atmosphere ◽  
Pyrolysis Process ◽  
Pyrolysis Mechanism ◽  
Second Stage ◽  
Friedman Method

The thermal degradation of PVC in air ambience was investigated by the thermogravimetric analysis (TGA). The experiments were carried out at different heating rate of 5, 10, 20 and 40°C/min, respectively. The activation energy was calculated by the Friedman method. The pyrolysis mechanism of PVC in air was discussed and compared with that in Nitrogen atmosphere. The pyrolysis process of PVC in air could be divided into two main stages: 200 °C ~ 380 °C and 400 °C ~ 600 °C, which obtained by TGA at the heating rate of 5°C/min. The second stage could be further subdivided into two parts by 465 °C. It can be concluded that the oxygen in air affected the second stage more obviously than that of the first one, in comparison with inert atmosphere. The activation energy of the second stage was still larger than the first stage.

Thermal degradation kinetics of poly(arylene ether nitrile) and its cross-linked polymer

2016 ◽  
Vol 29 (2) ◽  
pp. 211-217 ◽  
Author(s):  
Jiachun Zhong ◽  
Heng Guo ◽  
Jian Yang ◽  
Xiaobo Liu
Keyword(s):  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Decomposition Temperature ◽  
Thermal Degradation Kinetics ◽  
Initial Decomposition Temperature ◽  
Solid State Decomposition ◽  
Arylene Ether ◽  
Friedman Method ◽  
Kinetics Of ◽  
Good Agreement

The kinetics of the thermal degradation of poly(arylene ether nitrile) (PEN; cross-linked and uncross-linked) was investigated by thermogravimetric analysis. The corresponding kinetic parameters of PEN were determined using the Flynn–Wall–Ozawa and the Friedman method. The Satava method was also used to explore the probable degradation mechanisms of PEN. The results showed that the activation energy ( E) obtained from the Flynn–Wall–Ozawa method was in good agreement with the value obtained from the Friedman method. The solid-state decomposition mechanisms of uncross-linked and cross-linked PEN were A2 (nucleation and growth) and R2 type (phase boundary–controlled reaction), respectively. The E and initial decomposition temperature of cross-linked PEN were higher than those of uncross-linked PEN, which indicates that cross-linking treatment is effective in enhancing the thermal stability of PEN.

Relation between forest fuels composition and energy emitted during their thermal degradation

2009 ◽  
Vol 96 (1) ◽  
pp. 293-300 ◽  
Author(s):  
Valérie Leroy ◽  
Dominique Cancellieri ◽  
E. Leoni
Keyword(s):  
Thermal Degradation ◽  
Forest Fuels

Mediterranean Forest Fuels

2020 ◽  
pp. 765-777
Author(s):  
Kostas Kalabokidis ◽  
Palaiologos Palaiologou
Keyword(s):  
Mediterranean Forest ◽  
Forest Fuels

The Effect of Glycidyl Silane as Coupling Agent in Intumescent Flame Retardant System

2013 ◽  
Vol 664 ◽  
pp. 677-682
Author(s):  
Hambali Raden Siti Amirah ◽  
Ahmad Faiza Mohd ◽  
Mohd Firdaus Yhaya ◽  
Rahmah Mohamed ◽  
Mohamed Nur Raihan
Keyword(s):  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Ethylene Glycol ◽  
Burning Rate ◽  
Chemical Bonding ◽  
Coupling Agent ◽  
The Other ◽  
Silane Treatment ◽  
Char Formation

The effect of different carbonizing agents; ethylene glycol, glycerol, and pentaerythritol to the char formation were studied in this research. After burning process, formulation with ethylene glycol, glycerol, and pentaerythritol showed chars thickness of 10 mm, 32 mm, and 45 mm. The chars’ strength at peak force was recorded at 3.20 N, 7.75 N, and 9.48 N while the burning rate of each sample were 5.23 x 10-4 mm/s, 4.20 x10-4 mm/s, and 6.24 x10-4 mm/s respectively. Formulation with glycerol as carbonizing agent showed the lowest burning rate as compared to the other formulations. Additional formulation with glycidyl silane as coupling agent in glycerol formulation was also studied. The formation of chemical bonding between silane, glycerol, and epoxy glycerol was confirmed by Fourier Transform Infrared (FTIR) absorption peak at 767.25 cm-1. The burning rate was 1.44 x 10-5 mm/s after silane treatment. Thermal degradation of the silane-treated resin started at 220°C as measured by thermogravimetric analysis (TGA).

INVESTIGATION OF THERMAL DEGRADATION OF POULTRY PROCESSING DEWATERED SLUDGE USING THERMOGRAVIMETRIC ANALYSIS METHOD

2015 ◽  
Vol 76 (5) ◽  
Author(s):  
N. Aniza ◽  
S. Hassan ◽  
M. F. M. Nor ◽  
K. E. Kee ◽  
Aklilu T.
Keyword(s):  
Particle Size ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Heating Rate ◽  
Degradation Process ◽  
Heating Rates ◽  
Initial Stage ◽  
Poultry Processing ◽  
Effect Of Particle Size ◽  
Dewatered Sludge

Thermal degradation of Poultry Processing Dewatered Sludge (PPDS) was studied using thermogravimetric analysis (TGA) method. The effect of particle size on PPDS samples and operational condition such as heating rates were investigated. The non-isothermal TGA was run under a constant flow of oxygen at a rate of 30 mL/min with temperature ranging from 30ºC to 800ºC. Four sample particle sizes ranging between 0.425 mm to 2 mm, and heating rate between 5 K/min to 20 K/min were used in this study. The TGA results showed that particle size does not have any significant effect on the thermogravimetry (TG) curves at the initial stage, but the TG curves started to separate explicitly at the second stage. Particle size may affect the reactivity of sample and combustion performance due to the heat transfer and temperature gradient. The TG and peak of derivative thermogravimetry (DTG) curves tend to alter at high temperature when heating rate is increased most likely due to the limitation of mass transfer and the delay of degradation process. 

Non-isothermal degradation kinetics for polycarbonate/ polymethylphenylsilsesquioxane composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiangbo Wang ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Flame Retardancy ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Nitrogen Atmosphere ◽  
Ozawa Method ◽  
Degradation Behaviors ◽  
Thermal Degradation Process

AbstractThe thermal degradation behaviors of PC/PMPSQ (polymethylphenylsilsesquioxane) systems were investigated by thermogravimetric analysis (TGA) under non-isothermal conditions in nitrogen atmosphere. During non-isothermal degradation, Kissinger and Flynn-Wall-Ozawa methods were used to analyze the thermal degradation process. The results showed that a remarkable decrease in activation energy ( E ) was observed in the early and middle stages of thermal degradation in the presence of PMPSQ, which indicated that the addition of PMPSQ promoted the thermal degradation of PC. Flynn-Wall-Ozawa method further revealed that PMPSQ significantly increased the activation energy of PC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of PC in the final period of thermal degradation process

Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

2017 ◽  
Vol 30 (7) ◽  
pp. 787-793 ◽  
Author(s):  
Xu Su ◽  
Yong Xu ◽  
Linshuang Li ◽  
Chaoran Song
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Step Method ◽  
Nitrogen Derivative ◽  
Degradation Reaction ◽  
Kinetics Of

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

Thermogravimetric studies on co-pyrolysis of raw/torrefied biomass and coal blends

2020 ◽  
Vol 38 (11) ◽  
pp. 1259-1268
Author(s):  
NL Panwar ◽  
Bhautik Gajera ◽  
Sudhir Jain ◽  
BL Salvi
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Physicochemical Properties ◽  
Model Fitting ◽  
Cotton Stalk ◽  
Fitting Method ◽  
Torrefied Biomass ◽  
Three Stages ◽  
Thermogravimetric Studies ◽  
Kinetics Of

The pyrolysis and co-pyrolysis behaviours of cotton stalk (CS), torrefied cotton stalk (TCS) and mined coal, as single fuels, and their blends, have been examined through thermogravimetric analysis. Biomass has been torrefied at 250°C for 45 min to enhance physicochemical properties, and then mixed with mined coal for co-pyrolysis. Thermal degradation of CS and TCS is characterized by a reaction. However, this is not the case for mined coal, which shows a single-stage reaction. The thermal degradation of all blends was done in three stages: dehydration; biomass and small mined coal; and lignin or mined coal. A similar trend emerged for mass loss of individual fuels, which depended mainly on their ratios in the blend. The kinetics of pyrolysis and co-pyrolysis of all fuels were calculated at 20°Cmin−1 heating rate using the Coats−Redfern model-fitting method.

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