scholarly journals Thermogravimetric and Kinetic Analysis of High-Temperature Thermal Conversion of Pine Wood Sawdust under CO2/Ar

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5328
Author(s):  
Bao Wang ◽  
Yujie Li ◽  
Jianan Zhou ◽  
Yi Wang ◽  
Xun Tao ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Room Temperature ◽  
Thermal Conversion ◽  
Heating Rates ◽  
Pine Wood ◽  
Master Plot ◽  
Char Gasification ◽  
Wood Sawdust ◽  
Pine Wood Sawdust ◽  
Kinetics Of

The gasification behavior of pine wood sawdust was investigated in CO2 with different heating rates of 5, 10, 15, and 20 °C/min from room temperature to 1400 °C by thermogravimetric analysis (TGA) and mass spectrometry (MS). It was also examined under Ar to compare the differences observed under CO2 at heating rate of 10 °C/min. Kinetics of pine wood sawdust thermal decomposition was determined by the models of FWO, KAS and master plot method. TGA results revealed different reaction sections from pyrolysis to char gasification under CO2. The pyrolysis behavior was similar under CO2 and Ar and had a similar energy required value about 590 kJ/kg from 250 °C to 420 °C. CO, CH4, and H2 were the primary gases obtained from thermal decomposition, and the amounts of which in CO2 atmosphere were higher than those obtained in Ar. The average activation energy for pyrolysis under CO2 was 184.72 kJ/mol.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

scholarly journals Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Heating Rates ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Rate Loss ◽  
Kinetics Of

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

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).

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.

Pyrolysis of Sugarcane Bagasse: A Consecutive Reactions Kinetic Model from TGA Experiments

2010 ◽  
Vol 660-661 ◽  
pp. 593-598 ◽  
Author(s):  
Kássia Graciele dos Santos ◽  
Taisa S. Lira ◽  
Valéria V. Murata ◽  
Marco Gianesella ◽  
Marcos A.S. Barrozo
Keyword(s):  
Kinetic Model ◽  
Sugarcane Bagasse ◽  
Room Temperature ◽  
Linear Method ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Exponential Factor ◽  
Consecutive Reactions ◽  
Kinetics Of ◽  
Good Agreement

The pyrolysis kinetics of sugarcane bagasse in nitrogen flow was studied by thermogravimetric analysis from room temperature to 1173 K at different heating rates (1.5, 3, 5, 10, 15, 20, 30 and 50 K/min). As there are three distinct devolatilization peaks in the DTG curve, each peak was associated to thermal decomposition of an individual biomass subcomponent (hemicellulose, cellulose and lignin). The kinetic model adopted was a consecutive reactions model. The kinetic parameters of the pyrolysis process, such as activation energy and pre-exponential factor, were calculated by least squares non-linear method and Scilab are used as the simulation tool. The simulated results showed a good agreement with the experimental data and the parameters found are similar to reported by the literature.

Kinetics of Thermal Decomposition of Group-Hi Metal Alkyls on GaAs(100)

1990 ◽  
Vol 204 ◽  
Author(s):  
V. M. Donnelly ◽  
J. A. Mccaulley ◽  
R. J. Shul
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Semiconductor Films ◽  
Heating Rates ◽  
Kinetics Of Thermal Decomposition ◽  
Cracking Pattern ◽  
Kinetics Of ◽  
Metal Alkyls

ABSTRACTWe report studies of the kinetics of thermal decomposition of triethylgallium (TEGa), trimethylgallium (TMGa), and trimethylindium (TMIn) adsorbed on GaAs(100) in ultrahigh vacuum. The adsorbed layers were prepared by dosing GaAs(100) at room temperature, to either saturated coverage or coverages below saturation. Subsequent heating leads to loss of adsorbed hydrocarbons. The relative coverage of carbon was monitored by X-ray photoelectron spectroscopy (XPS), and products were detected with a differentially pumped quadrupole mass spectrometer. The kinetic analysis also includes measurements of laser-induced, rapid thermal decomposition (heating rates of ∼1011°C/s).TEGa dissociatively chemisorbs on GaAs(100). Heating the substrate results in desorption of diethylgallium radicals at low temperature and C2H4 (and some C2H5) at higher temperatures, after most of the diethylgallium has desorbed. TMGa decomposes to yield a Ga-alkyl desorption product (either dimethylgallium, or a mixture of dimethylgallium and TMGa) at low temperature and CH3 at higher temperature. TMIn undergoes a methyl exchange reaction on GaAs(100) where a Ga-alkyl desorbs with the same cracking pattern as in TMGa decomposition. Decomposition mechanisms for these group-III metal alkyls are proposed, Arrhenius parameters are presented, and some implications are discussed for growth of Ga-containing III-V compound semiconductor films from these precursors by chemical vapor deposition and molecular beam techniques.

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