Theoretical Thermogravimetric Analysis at Constant Heating Rates

1980 ◽  
pp. 51-56 ◽  
Author(s):  
C. Comel ◽  
J. Veron ◽  
C. Bouster ◽  
P. Vermande
Keyword(s):  
Thermogravimetric Analysis ◽  
Heating Rates ◽  
Constant Heating

Thermal Characterization Study of Eucalyptus Sourced from South China with Thermo-Kinetic Analysis Method

2013 ◽  
Vol 860-863 ◽  
pp. 479-484
Author(s):  
Ye Tang ◽  
Dian Zheng Fu ◽  
Zheng Hui Fu ◽  
Hong Liang Zhang ◽  
Wei Li
Keyword(s):  
Thermogravimetric Analysis ◽  
Kinetic Analysis ◽  
South China ◽  
Kinetic Method ◽  
Thermal Characterization ◽  
Volatile Matter ◽  
Analysis Method ◽  
Heating Rates ◽  
Characterization Study ◽  
Constant Heating

In this study, thermogravimetric analysis and kinetic analysis techniques were used to investigating the pyrolysis characteristic of the eucalyptus feedstock sourced from South China. The thermogravimetric analysis results indicate that the pyrolysis of eucalyptus sample occurred in three main stages which are the moisture vaporization stage, the volatile matter release stage and the char decomposition stage. The kinetic analysis results show that C-R kinetic method fits to the pyrolysis characterizations of eucalyptus. In addition, the effects of different constant heating rates on the pyrolysis behavior and kinetic parameters have been also studied in this paper.

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. 

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.

scholarly journals Thermal Behavior of Sweet Potato Starch by Non-Isothermal Thermogravimetric Analysis

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 699 ◽  
Author(s):  
Ying Liu ◽  
Liutao Yang ◽  
Chunping Ma ◽  
Yingzhe Zhang
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Sweet Potato ◽  
Degradation Kinetics ◽  
Potato Starch ◽  
Activation Energies ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Sweet Potato Starch

In this study, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) methods were used to study the structure, the thermal degradation kinetics, and the thermogram of sweet potato starch, respectively. The thermal decomposition kinetics of sweet potato starch was examined within different heating rates in a nitrogen atmosphere. Different models of kinetic analysis were used to calculate the activation energies using the thermogravimetric data of the thermal degradation process. The activation energies got from Kissinger, Flynn–Wall–Ozawa, and Šatava–Šesták models were 173.85, 174.87, and 174.34 kJ·mol−1, respectively. Thermogravimetry–Fourier transform infrared spectroscopy (TG-FTIR) analysis showed that the main pyrolysis products included water, carbon dioxide, and methane.

scholarly journals Kinetic studies on the pyrolysis of plastic waste using a combination of model-fitting and model-free methods

2020 ◽  
Vol 38 (1_suppl) ◽  
pp. 77-85 ◽  
Author(s):  
Zhitong Yao ◽  
Shaoqi Yu ◽  
Weiping Su ◽  
Weihong Wu ◽  
Junhong Tang ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Thermogravimetric Analysis ◽  
Compensation Effect ◽  
Model Fitting ◽  
Plastic Waste ◽  
Plastic Shell ◽  
Ozawa Method ◽  
Heating Rates ◽  
Helium Atmosphere ◽  
Model Free

In this work, the pyrolysis behavior of plastic waste—TV plastic shell—was investigated, based on thermogravimetric analysis and using a combination of model-fitting and model-free methods. The possible reaction mechanism and kinetic compensation effects were also examined. Thermogravimetric analysis indicated that the decomposition of plastic waste in a helium atmosphere can be divided into three stages: the minor loss stage (20–300°C), the major loss stage (300–500°C) and the stable loss stage (500–1000°C). The corresponding weight loss at three different heating rates of 15, 25 and 35 K/min were determined to be 2.80–3.02%, 94.45–95.11% and 0.04–0.16%, respectively. The activation energy ( Ea) and correlation coefficient ( R2) profiles revealed that the kinetic parameters calculated using the Friedman and Kissinger–Akahira–Sunose method displayed a similar trend. The values from the Flynn–Wall–Ozawa and Starink methods were comparable, although the former gave higher R2 values. The Eα values gradually decreased from 269.75 kJ/mol to 184.18 kJ/mol as the degree of conversion ( α) increased from 0.1 to 0.8. Beyond this range, the Eα slightly increased to 211.31 kJ/mol. The model-fitting method of Coats–Redfern was used to predict the possible reaction mechanism, for which the first-order model resulted in higher R2 values than and comparable Eα values to those obtained from the Flynn–Wall–Ozawa method. The pre-exponential factors (ln A) were calculated based on the F1 reaction model and the Flynn–Wall–Ozawa method, and fell in the range 59.34–48.05. The study of the kinetic compensation effect confirmed that a compensation effect existed between Ea and ln A during the plastic waste pyrolysis.

Application of Master Sintering Curve Theory to Predict and Control the Sintering of Nanocrystalline TiO2 Ceramic

2008 ◽  
Vol 368-372 ◽  
pp. 1588-1590
Author(s):  
Da Li ◽  
Shaou Chen ◽  
Wei Quan Shao ◽  
Xiao Hui Ge ◽  
Yong Cheng Zhang ◽  
...  
Keyword(s):  
Sintering Behavior ◽  
Heating Rates ◽  
Temperature Function ◽  
Rutile Tio2 ◽  
Densification Curve ◽  
Final Density ◽  
Thermal Histories ◽  
Constant Heating ◽  
And Control ◽  
Temperature Time

Master sintering curve (MSC), in which the sintered density is a unique function of the integral of a temperature function over time, is insensitive to the heating path. In this paper, the densification of rutile TiO2 was continuously recorded at heating rates of 2 °C/min and 5 °C/min, respectively, by dilatometer. The MSC for rutile TiO2 was constructed for pressureless sintering using constant heating rate date based on the combined-stage sintering model. The construction and application of the MSC were described in detail for different thermal histories. The MSC can be used to predict and control the densification, final density, and microstructure evolution during the whole sintering. The final density can be predicted for an arbitrary temperature–time path. A good consistence exists between the predicted and experimental densification curve, confirming that it is possible to accurately predict and control the sintering behavior of TiO2 from the initial to final stage of sintering using MSC.

scholarly journals Nonisothermal Thermogravimetric Analysis of Thai Lignite with High CaO Content

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pakamon Pintana ◽  
Nakorn Tippayawong
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Combustion Kinetics ◽  
Heating Rates ◽  
Thermogravimetric Method ◽  
Degradation Behaviors ◽  
Fwo Method ◽  
Free Cao ◽  
Kinetics Of

Thermal behaviors and combustion kinetics of Thai lignite with different SO3-free CaO contents were investigated. Nonisothermal thermogravimetric method was carried out under oxygen environment at heating rates of 10, 30, and 50°C min−1from ambient up to 1300°C. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods were adopted to estimate the apparent activation energy (E) for the thermal decomposition of these coals. Different thermal degradation behaviors were observed in lignites with low (14%) and high (42%) CaO content. Activation energy of the lignite combustion was found to vary with the conversion fraction. In comparison with the KAS method, higherEvalues were obtained by the FWO method for all conversions considered. High CaO lignite was observed to have higher activation energy than the low CaO coal.

Thickness Effect On The Crystallization Kinetics Of Electrolessly-Deposited Ni(P) Thin Films

1993 ◽  
Vol 321 ◽  
Author(s):  
L. T. Shi ◽  
E. J. M. O'Sullivan
Keyword(s):  
Thin Films ◽  
Crystallization Kinetics ◽  
Annealing Temperature ◽  
Sample Thickness ◽  
Thickness Effect ◽  
Heating Rates ◽  
Activation Energy Of Crystallization ◽  
Constant Heating ◽  
Kinetics Of ◽  
Seed Layers

ABSTRACTIn order to understand thickness and interfacial effects on the crystallization kinetics of amorphous solids, Ni(P) thin films electrolessly deposited on Cu seed layers were annealed at constant heating rates or at constant temperatures in a DSC to obtain activation energies andAvrami exponents. It was found that the activation energy of crystallization in Ni(P) changes asa function of sample thickness when the sample thickness is less than 1.0 μm. Furthermore, the Avrami exponent was found to change not only as a function of thickness but also as a function of annealing temperature.

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