Pyrolytic Characteristics and Kinetics of Xanthoceras Sorbifolia Oil

2012 ◽  
Vol 178-181 ◽  
pp. 1093-1096
Author(s):  
Quan Cheng Zhou ◽  
Gui Hua Sheng
Keyword(s):  
Activation Energy ◽  
Reaction Rates ◽  
Inert Atmosphere ◽  
Probable Mechanism ◽  
Heating Rates ◽  
Moisture Evaporation ◽  
Average Activation Energy ◽  
Exponential Factors ◽  
Three Stages ◽  
Kinetics Of

The pyrolytic characteristics and kinetics of Xanthoceras sorbifolia oil were investigated pyrolysis in indifferent atmosphere and at heating rates of 10, 20 and 30 °C min-1 in an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO and KAS methods. Three stages appeared during pyrolysis: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the X. sorbifolia oil were observed. Stage II of the X. sorbifolia oil could be described by the Avramic- Erofeev equation 20 (n=4). The average activation energy of X. sorbifolia oil was 353 kJ mol-1

Evalution of the Pyrolytic and Kinetics Characteristics of Xanthoceras sorbifolia Oil

2012 ◽  
Vol 512-515 ◽  
pp. 401-404
Author(s):  
Gui Hua Sheng ◽  
Quan Cheng Zhou ◽  
De Mao Li
Keyword(s):  
Activation Energy ◽  
Reaction Rates ◽  
Inert Atmosphere ◽  
Heating Rates ◽  
Moisture Evaporation ◽  
Average Activation Energy ◽  
Power Equation ◽  
Exponential Factors ◽  
Three Stages ◽  
Kinetics Of

The pyrolytic characteristics and kinetics of Xanthoceras sorbifolia oil were investigated at heating rates of 10, 20 and 30 °C min-1in an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO and KAS methods. Three stages appeared during pyrolysis: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the X. sorbifolia oil at different heating rate were observed. Stage II of the X. sorbifolia oil could be described by the Mampel Power equation 22 (n=0.25). The average activation energy of X. sorbifolia oil was 346 kJ mol-1.

scholarly journals Kinetic analysis of oil palm empty fruit bunch (OPEFB) pellets as feedstock for pyrolysis

2015 ◽  
Author(s):  
Bemgba Bevan Nyakuma
Keyword(s):  
Activation Energy ◽  
Oil Palm ◽  
Room Temperature ◽  
Energy Requirement ◽  
Inert Atmosphere ◽  
Decomposition Kinetics ◽  
The Other ◽  
Empty Fruit Bunch ◽  
Heating Rates ◽  
Kinetics Of

The thermal behaviour and decomposition kinetics of pelletized oil palm empty fruit bunch (OPEFB) was investigated in this study using thermogravimetric analysis (TGA). The OPEFB pellets were heated from room temperature to 1000 ºC at different heating rates; 5, 10 and 20 °C min-1 under inert atmosphere. Thermal degradation occurred in three steps; drying, devolatization and char decomposition. Subsequently, the Popescu method was applied to the TG/DTG data to determine the kinetic parameters of the OPEFB pellets. The activation energy, E, for different degrees of conversion, α = 0.05 to 0.7 are 36.60 kJ/mol to 233.90 kJ/mol with high correlation R2 values. In addition, the drying and decomposition of lignin reactions displayed lower E values compared to the devolatization characterized by high E value of 233 kJ/mol at α = 0.2. This indicates that the devolatization process is slower and requires higher energy requirement to reach completion than the other stages of thermal decomposition of the fuel under inert atmosphere. Keywords: decomposition, kinetics, oil palm, empty fruit bunch, pyrolysis.

scholarly journals Kinetic analysis of oil palm empty fruit bunch (OPEFB) pellets as feedstock for pyrolysis

2015 ◽  
Author(s):  
Bemgba Bevan Nyakuma
Keyword(s):  
Activation Energy ◽  
Oil Palm ◽  
Room Temperature ◽  
Energy Requirement ◽  
Inert Atmosphere ◽  
Decomposition Kinetics ◽  
The Other ◽  
Empty Fruit Bunch ◽  
Heating Rates ◽  
Kinetics Of

The thermal behaviour and decomposition kinetics of pelletized oil palm empty fruit bunch (OPEFB) was investigated in this study using thermogravimetric analysis (TGA). The OPEFB pellets were heated from room temperature to 1000 ºC at different heating rates; 5, 10 and 20 °C min-1 under inert atmosphere. Thermal degradation occurred in three steps; drying, devolatization and char decomposition. Subsequently, the Popescu method was applied to the TG/DTG data to determine the kinetic parameters of the OPEFB pellets. The activation energy, E, for different degrees of conversion, α = 0.05 to 0.7 are 36.60 kJ/mol to 233.90 kJ/mol with high correlation R2 values. In addition, the drying and decomposition of lignin reactions displayed lower E values compared to the devolatization characterized by high E value of 233 kJ/mol at α = 0.2. This indicates that the devolatization process is slower and requires higher energy requirement to reach completion than the other stages of thermal decomposition of the fuel under inert atmosphere. Keywords: decomposition, kinetics, oil palm, empty fruit bunch, pyrolysis.

scholarly journals Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  
Keyword(s):  
Activation Energy ◽  
Waste Management ◽  
Energy Demand ◽  
Power Plants ◽  
Combustion Process ◽  
Isoconversional Methods ◽  
Low Rank ◽  
Heating Rates ◽  
Average Activation Energy ◽  
Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

Thermo-catalytic decomposition of polystyrene waste: Comparative analysis using different kinetic models

2019 ◽  
Vol 38 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Ghulam Ali ◽  
Jan Nisar ◽  
Munawar Iqbal ◽  
Afzal Shah ◽  
Mazhar Abbas ◽  
...  
Keyword(s):  
Activation Energy ◽  
Copper Oxide ◽  
Solid Waste ◽  
Thermodynamic Parameters ◽  
Model Fitting ◽  
Catalytic Decomposition ◽  
Decomposition Reaction ◽  
Inert Atmosphere ◽  
Heating Rates ◽  
Model Free

Due to a huge increase in polymer production, a tremendous increase in municipal solid waste is observed. Every year the existing landfills for disposal of waste polymers decrease and the effective recycling techniques for waste polymers are getting more and more important. In this work pyrolysis of waste polystyrene was performed in the presence of a laboratory synthesized copper oxide. The samples were pyrolyzed at different heating rates that is, 5°Cmin−1, 10°Cmin−1, 15°Cmin−1 and 20°Cmin−1 in a thermogravimetric analyzer in inert atmosphere using nitrogen. Thermogravimetric data were interpreted using various model fitting (Coats–Redfern) and model free methods (Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman). Thermodynamic parameters for the reaction were also determined. The activation energy calculated applying Coats–Redfern, Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman models were found in the ranges 105–148.48 kJmol−1, 99.41–140.52 kJmol−1, 103.67–149.15 kJmol−1 and 99.93–141.25 kJmol−1, respectively. The lowest activation energy for polystyrene degradation in the presence of copper oxide indicates the suitability of catalyst for the decomposition reaction to take place at lower temperature. Moreover, the obtained kinetics and thermodynamic parameters would be very helpful in determining the reaction mechanism of the solid waste in a real system.

Magnetic Properties, Nanostructure, and Ordering Kinetics of Nb Additive FePtCu Films

2010 ◽  
Vol 638-642 ◽  
pp. 1743-1748
Author(s):  
G.J. Chen ◽  
Y.H. Shih ◽  
Jason S.C. Jang ◽  
S.R. Jian ◽  
P.H. Tsai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Magnetic Properties ◽  
Heating Rates ◽  
Fept Alloy ◽  
Ordering Kinetics ◽  
Nb Content ◽  
Kinetics Of ◽  
Nb Addition ◽  
Microstructure And Magnetic Properties

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.

Mechanisms and kinetics of initial pyrolysis and combustion reactions of 1,1-diamino-2,2-dinitroethylene from density functional tight-binding molecular dynamics simulations

2019 ◽  
Vol 97 (11) ◽  
pp. 795-804 ◽  
Author(s):  
Dong Xiang ◽  
Weihua Zhu
Keyword(s):  
Activation Energy ◽  
Molecular Dynamics ◽  
Density Functional ◽  
Tight Binding ◽  
Combustion Process ◽  
Exponential Factor ◽  
Three Stages ◽  
Dynamics Simulations ◽  
Combustion Processes ◽  
Kinetics Of

The density functional tight-binding molecular dynamics approach was used to study the mechanisms and kinetics of initial pyrolysis and combustion reactions of isolated and multi-molecular FOX-7. Based on the thermal cleavage of bridge bonds, the pyrolysis process of FOX-7 can be divided into three stages. However, the combustion process can be divided into five decomposition stages, which is much more complex than the pyrolysis reactions. The vibrations in the mean temperature contain nodes signifying the formation of new products and thereby the transitions between the various stages in the pyrolysis and combustion processes. Activation energy and pre-exponential factor for the pyrolysis and combustion reactions of FOX-7 were obtained from the kinetic analysis. It is found that the activation energy of its pyrolysis and combustion reactions are very low, making both take place fast. Our simulations provide the first atomic-level look at the full dynamics of the complicated pyrolysis and combustion process of FOX-7.

scholarly journals Non-Isothermal Sublimation Kinetics of 2,4,6-Trinitrotoluene (TNT) Nanofilms

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1163 ◽  
Author(s):  
Walid Hikal ◽  
Brandon Weeks
Keyword(s):  
Activation Energy ◽  
Analytical Techniques ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Absorbance Spectroscopy ◽  
Calculated Activation Energy ◽  
Sublimation Kinetics ◽  
Sublimation Rates ◽  
First Time ◽  
Kinetics Of

Non-isothermal sublimation kinetics of low-volatile materials is more favorable over isothermal data when time is a crucial factor to be considered, especially in the subject of detecting explosives. In this article, we report on the in-situ measurements of the sublimation activation energy for 2,4,6-trinitrotoluene (TNT) continuous nanofilms in air using rising-temperature UV-Vis absorbance spectroscopy at different heating rates. The TNT films were prepared by the spin coating deposition technique. For the first time, the most widely used procedure to determine sublimation rates using thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) was followed in this work using UV-Vis absorbance spectroscopy. The sublimation kinetics were analyzed using three well-established calculating techniques. The non-isothermal based activation energy values using the Ozawa, Flynn–Wall, and Kissinger models were 105.9 ± 1.4 kJ mol−1, 102.1 ± 2.7 kJ mol−1, and 105.8 ± 1.6 kJ mol−1, respectively. The calculated activation energy agreed well with our previously reported isothermally-measured value for TNT nanofilms using UV-Vis absorbance spectroscopy. The results show that the well-established non-isothermal analytical techniques can be successfully applied at a nanoscale to determine sublimation kinetics using absorbance spectroscopy.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

Non-Isothermal Crystallization Kinetics of Mg61Zn35Ca4 Glassy Alloy

2017 ◽  
Vol 898 ◽  
pp. 657-665
Author(s):  
Dao Zhang ◽  
Wang Shu Lu ◽  
Xiao Yan Wang ◽  
Sen Yang
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Melt Spinning ◽  
Glassy Alloy ◽  
Heating Rates ◽  
Isothermal Crystallization Kinetics ◽  
Complex Process ◽  
Activation Energy Of Crystallization ◽  
Kinetics Of

The non-isothermal crystallization kinetics of Mg61Zn35Ca4 glassy alloy prepared via melt-spinning were studied by using isoconversion method. The crystalline characterization of Mg61Zn35Ca4 was examined by X-ray diffraction. Different scanning calorimeter was used to investigate the non-isothermal crystallization kinetics at different heating rates (3-60 K/min). The calculated value of Avrami exponent obtained by Matusita method indicated that the crystalline transformation for Mg61Zn35Ca4 is a complex process of nucleation and growth. The Kissinger-Akahira-Sunose method was used to investigate the activation energy. The activation energy of crystallization varies with the extent of crystallization and hence with temperature. The Sestak-Berggren model was used to describe the non-isothermal crystallization kinetics.

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