scholarly journals Thermal Degradation Characteristics and Kinetics of Oxy Combustion of Corn Residues

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Poramate Sittisun ◽  
Nakorn Tippayawong ◽  
Darunee Wattanasiriwech
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Degradation Process ◽  
Similar Magnitude ◽  
Heating Rates ◽  
Decomposition Rates ◽  
Similar Weight ◽  
Thermal Degradation Process ◽  
Kinetics Of ◽  
Corn Residues

Thermogravimetric analysis was used to investigate oxy combustion of corncob and stover. The biomass samples were heated from ambient temperature to 900°C at different heating rates of 10, 30, and 50 K/min. Both biomass samples showed similar weight loss patterns with three zones, corresponding to dehydration, devolatilization, and char combustion, but displayed different degradation temperatures. Increasing heating rate was found to shift the degradation patterns to higher temperatures. Decomposition rates of cob and stover may have been influenced by their lignocellulosic composition. The kinetic parameters of the thermal degradation process were also determined and compared using the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods. Both methods were found to give similar values and patterns of activation energy against conversion fraction. The average values were found to be in similar magnitude to those reported in the literature, around 170 and 148 kJ/mol for cob and stover, respectively.

scholarly journals Thermal degradation process of polysulfone aramid fiber

2014 ◽  
Vol 18 (5) ◽  
pp. 1637-1641 ◽  
Author(s):  
Fang-Long Zhu ◽  
Qian-Qian Feng ◽  
Qun Xin ◽  
Yu Zhou
Keyword(s):  
Thermal Degradation ◽  
Degradation Process ◽  
Aramid Fiber ◽  
Degradation Behavior ◽  
Heating Rates ◽  
Degradation Temperature ◽  
Mass Losses ◽  
Thermal Degradation Behavior ◽  
Thermal Degradation Process ◽  
Kinetics Of

Polysulfone aramid fiber is one kind of high temperature fibers. In the paper, thermal degradation behavior and kinetics of polysulfone aramid fiber were investigated by thermogravimetric analysis and differential thermogravimetric at different heating rates under nitrogen and air, respectively. The experimental results show that its initial degradation temperature is 375?C in nitrogen and 410?C in air at heating rate of 10 K/min. When temperature went to 800?C, the fiber loses all mass in air. The mass losses in the stage showed that degradation of polysulfone aramid occurs in two-step process as could be concluded by the presence of two distinct exothermic peaks in differential thermogravimetric curves.

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.

scholarly journals Devolatilization of African Palm (Elaeis guineensis) Husk studied by TG-MS

2018 ◽  
Vol 38 (2) ◽  
pp. 9-17
Author(s):  
Alberto Ricardo Albis Arrieta ◽  
Ever Ortiz Muñoz ◽  
Ismael Piñeres Ariza ◽  
Andrés Felipe Suárez Escobar ◽  
Marley Cecilia Vanegas Chamorro
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Mass Spectroscopy ◽  
Elaeis Guineensis ◽  
Degradation Process ◽  
Pyrolysis Process ◽  
Distributed Activation Energy Model ◽  
Evolved Gas ◽  
Secondary Reactions ◽  
Thermal Degradation Process

 Using simultaneous thermogravimetrical analysis coupled with mass spectroscopy, the pyrolysis of African palm husk, using several heat rates and programs was performed. Seven relations of mass/charge were followed of the evolved gas of the pyrolysis process, fitting the kinetics and the mass spectroscopy signals to the distributed activation energy model (DAEM) with different numbers of pseudo-components. Fitting with four pseudo-components proved to be the best for modeling the thermal degradation process. Kinetic parameters were not affected by the heating rate or program employed, which agrees with other reports for similar biomass. Methane, methanol formaldehyde, furfural were successfully fitted to the DAEM model, nevertheless CO2 and NO2 were not able to be represented by this model due to its production in secondary reactions in gaseous phase.

Effect of Pd Nanoparticle on the Thermal Degradation Kinetics of Nylon 6/Pd Nanocomposite Prepared by a Dry Process

2012 ◽  
Vol 486 ◽  
pp. 27-33 ◽  
Author(s):  
Jae Young Lee ◽  
Sung Wan Hong ◽  
Kyeong Sik Han ◽  
Taeck Hong Lee ◽  
Hong Ki Lee
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Pd Nanoparticles ◽  
Nylon 6 ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Dry Process ◽  
Effect Of Pd ◽  
Kinetics Of

Palladium (Pd) nanoparticles were incorporated into a nylon 6 film via a dry process which consisted of simultaneous vaporization, penetration and reduction processes of palladium (II) bis (acetylacetonate, Pd (acac)2) at 180°C for various exposure time. The even dispersion of the generated Pd nanoparticles were observed by transmission electron microscope (TEM) and the Pd loading weight of about 15~43 wt% was measured by thermogravimetric analysis (TGA). In order to study the catalytic effect of Pd nanoparticles on the thermal degradation kinetics of nylon 6, TGA data at various heating rates were introduced to Flynn & Wall equation. The thermal degradation activation energy for neat nylon 6 was ca. 162~178 kJ/mol over the thermal degradation fraction of 0.05~0.40 while that of the nylon 6/Pd (26.5 wt%) nanocomposite was ca. 110~169 kJ/mol over the same fraction range. It meant the Pd nanoparticles were acted as a catalyst on the depolymerization of amide group in nylon 6. It was also found that the activation energy decreased slightly with the increasing Pd loading weight.

Thermal degradation kinetics of oxo-degradable PP/PLA blends

2018 ◽  
Vol 39 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Dev K. Mandal ◽  
Haripada Bhunia ◽  
Pramod K. Bajpai
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Kinetic Parameters ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Kinetics Of

AbstractIn this article, the influence of polylactide and pro-oxidant on the thermal stability, degradation kinetics, and lifetime of polypropylene has been investigated using thermogravimetric analysis under nitrogen atmosphere at four different heating rates (i.e. 5, 10, 15, and 20°C/min). The kinetic parameters of degradation were studied over a temperature range of 30–550°C. The derivative thermogravimetric curves have indicated single stage and two stage degradation processes. The activation energy was evaluated by using the Kissinger, Kim-Park, and Flynn-Wall methods under the nitrogen atmosphere. The activation energy value of polypropylene was much higher than that of polylactide. Addition of polylactide and pro-oxidant in polypropylene decreased the activation energy. The lifetime of polypropylene has also decreased with the addition of polylactide and pro-oxidant.

Thermal Stability and Kinetic Analysis of Xanthoceras sorbifolia Polysaccharide

2012 ◽  
Vol 518-523 ◽  
pp. 3904-3907 ◽  
Author(s):  
Quan Cheng Zhou ◽  
Hong Mei Zhang ◽  
De Mao Li
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Kinetic Model ◽  
Thermal Degradation ◽  
Kinetic Analysis ◽  
Large Scale ◽  
Degradation Process ◽  
Second Step ◽  
Step Process ◽  
Thermal Degradation Process

Pyrolysis and kinetic analysis of Xanthoceras Sorbifolia polysaccharide were evaluated using the TG-DTG/DTA method. The results indicated that its mass loss occured in three-step process . The first step could be attributed to the expulsion of water of crystallization at 25 - 176 °C. The second step corresponded to the large scale degradation of X. Sorbifolia polysaccharide in the temperature range of 179 - 661 °C. The final step was slow degradation of residues. Heating rate had significant effects on the pyrolysis of X. Sorbifolia polysaccharide and nitrogen could improve its stability. A close value of activation energy E of the thermal degradation process has been obtained by FWO, KAS and Popescu methods. The possible kinetic model was estimated to be Jander 5 (g(α)=[1-(1-α)1/3]1/2.

Kinetics of Thermal Degradation of Ionic Liquid Regenerated Cellulose

2012 ◽  
Vol 488-489 ◽  
pp. 923-927
Author(s):  
Nawshad Muhammad ◽  
Zakaria B. Man ◽  
M. Azmi Bustam Khalil ◽  
Sikander Rafiq
Keyword(s):  
Activation Energy ◽  
Ionic Liquid ◽  
Kinetic Model ◽  
Thermal Degradation ◽  
Kinetic Parameters ◽  
Dynamic Condition ◽  
Degradation Process ◽  
Waste Paper ◽  
Regenerated Cellulose ◽  
Kinetics Of

In the present work ionic liquid has been used for the regeneration of cellulose from waste writing paper. The regenerated cellulose was characterized by TGA, FTIR and XRD analyses. Kinetics of thermal degradation of this cellulose was carried out under dynamic condition using thermogravimetry. Coats-Redfern kinetic model was used to determine the kinetic parameters for the degradation process. The activation energy for the thermal degradation of the regenerated cellulose has been found to be less than the precursor waste paper.

Using the Agrawal integral equation to study the thermal degradation of polyvinyl acetate-montmorillonite-dioctadecyl dimethyl ammonium bromide

2013 ◽  
Vol 33 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Qun Fang ◽  
Hui-wan Cui ◽  
Guan-ben Du
Keyword(s):  
Integral Equation ◽  
Thermal Degradation ◽  
Polyvinyl Acetate ◽  
Pyrolysis Temperature ◽  
Degradation Process ◽  
Ammonium Bromide ◽  
Pyrolysis Kinetics ◽  
Dimethyl Ammonium ◽  
Thermal Degradation Process ◽  
Kinetics Of

Abstract To study the pyrolysis kinetics of exfoliated nanocomposites, polyvinyl acetate (PVAc)-montmorillonite (MMT)-dioctadecyl dimethyl ammonium bromide (DOAB) was prepared through five different synthesis processes. The synthesis processes and MMT-DOAB had some effect on the thermal degradation, which was found to consist of eight phases. MMT-DOAB had no significant effect on the pyrolysis temperature, but delayed the thermal degradation process. The pyrolysis kinetics in thermal degradation were analyzed using the Agrawal integral equation.

scholarly journals Decomposition Characteristics and Kinetics of Microalgae in N2 and CO2 Atmospheres by a Thermogravimetry

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Xu Qing ◽  
Ma Xiaoqian ◽  
Yu Zhaosheng ◽  
Cai Zilin ◽  
Ling Changming
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Apparent Activation Energy ◽  
Kinetic Parameters ◽  
Reaction Order ◽  
Heating Rates ◽  
Residual Mass ◽  
Second Stage ◽  
Kinetics Of

The thermal degradation characteristics of microalgae were investigated in highly purified N2 and CO2 atmospheres by a thermogravimetric analysis (TGA) under different heating rates (10, 20, and 40°C/min). The results indicated that the total residual mass in CO2 atmosphere (16.86%) was less than in N2 atmosphere (23.12%); in addition, the kinetics of microalgae in N2 and CO2 atmospheres could be described by the pseudo bicomponent separated state model (PBSM) and pseudo-multi-component overall model (PMOM), respectively. The kinetic parameters calculated by Coats-Redfern method showed that, in CO2 atmosphere, the apparent activation energy (E) of microalgae was between 9.863 and 309.381 kJ mol−1 and the reaction order (n) was varied from 1.1 to 7. The kinetic parameters (E,n) of the second stage in CO2 atmosphere were quite similar to those in N2 atmosphere.

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