scholarly journals Kinetic Analysis of the Thermal Decomposition of Latex Foam according to Thermogravimetric Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hongwei Fan ◽  
Yongliang Chen ◽  
Dongmei Huang ◽  
Guoqin Wang
Keyword(s):  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Preexponential Factor ◽  
Kinetic Mechanism ◽  
Heating Rates ◽  
Third Order ◽  
Before And After ◽  
Ft Ir ◽  
The Mean ◽  
Nonisothermal Method

The thermal decomposition of latex foam was investigated under nonisothermal conditions. Pieces of commercial mattress samples were subjected to thermogravimetric analysis (TG) over a heating range from 5°C min−1 to 20°C min−1. The morphology of the latex foam before and after combustion was observed by scanning electron microscopy (SEM), and the primary chemical composition was investigated via infrared spectroscopy (FT-IR). The kinetic mechanism and relevant parameters were calculated. Results indicate that the decomposition of latex foam in the three major degradation phases is controlled by third-order reaction (F3) and by Zhuravlev’s diffusion equation (D5). The mean E values of each phase as calculated according to a single heating rate nonisothermal method are equal to 41.91 ± 0.06 kJ mol−1, 86.32 ± 1.04 kJ mol−1, and 19.53 ± 0.11 kJ mol−1, respectively. Correspondingly, the preexponential factors of each phase are equal to 300.39 s−1, 2355.65 s−1, and 27.90 s−1, respectively. The mean activation energy E and preexponential factor A of latex foam estimated according to multiple heating rates and a nonisothermal method are 92.82 kJ mol−1 and 1.12 × 10−3 s−1, respectively.

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.

scholarly journals Thermal Decomposition Kinetic Study of Non-Recyclable Paper and Plastic Waste by Thermogravimetric Analysis

2021 ◽  
Vol 5 (3) ◽  
pp. 54
Author(s):  
Ahmad Mohamed S. H. Al-Moftah ◽  
Richard Marsh ◽  
Julian Steer
Keyword(s):  
Power Generation ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Thermal Treatment ◽  
Solid Waste ◽  
Heating Rate ◽  
Heating Rates ◽  
Exponential Factor ◽  
Model Free ◽  
Treatment Processes

The global net emissions of the Kyoto Protocol greenhouse gases (GHG), such as carbon dioxide (CO2), fluorinated gases, methane (CH4), and nitrous oxide (N2O), remain substantially high, despite concerted efforts to reduce them. Thermal treatment of solid waste contributes at least 2.8–4% of the GHG in part due to increased generation of municipal solid waste (MSW) and inefficient treatment processes, such as incineration and landfill. Thermal treatment processes, such as gasification and pyrolysis, are valuable ways to convert solid materials, such as wastes into syngas, liquids, and chars, for power generation, fuels, or for the bioremediation of soils. Subcoal™ is a commercial product based on paper and plastics from the source segregated waste that is not readily recyclable and that would otherwise potentially find its way in to landfills. This paper looks at the kinetic parameters associated with this product in pyrolysis, gasification, and combustion conditions for consideration as a fuel for power generation or as a reductant in the blast furnace ironmaking process. Thermogravimetric Analysis (TGA) in Nitrogen (N2), CO2, and in air, was used to measure and compare the reaction kinetics. The activation energy (Ea) and pre-exponential factor A were measured at different heating rates using non-isothermal Ozawa Flynn Wall and (OFW) and Kissinger-Akahira-Sonuse (KAS) model-free techniques. The TGA curves showed that the thermal degradation of Subcoal™ comprises three main processes: dehydration, devolatilization, and char and ash formation. In addition, the heating rate drifts the devolatilization temperature to a higher value. Likewise, the derivative thermogravimetry (DTG) results stated that Tm degradation increased as the heating rate increased. Substantial variance in Ea was noted between the four stages of thermal decomposition of Subcoal™ on both methods. The Ea for gasification reached 200.2 ± 33.6 kJ/mol by OFW and 179.0 ± 31.9 kJ/mol by KAS. Pyrolysis registered Ea values of 161.7 ± 24.7 kJ/mol by OFW and 142.6 ± 23.5 kJ/mol by KAS. Combustion returned the lowest Ea values for both OFW (76.74 ± 15.4 kJ/mol) and KAS (71.0 ± 4.4 kJ/mol). The low Ea values in combustion indicate shorter reaction time for Subcoal™ degradation compared to gasification and pyrolysis. Generally, TGA kinetics analysis using KAS and OFW methods show good consistency in evaluating Arrhenius constants.

Effect of annealing temperature on structural and magnetic properties of strontium hexaferrite nanoparticles synthesized by sol–gel auto-combustion method

2015 ◽  
Vol 29 (27) ◽  
pp. 1550190 ◽  
Author(s):  
Ebrahim Roohani ◽  
Hadi Arabi ◽  
Reza Sarhaddi ◽  
Saeedeh Sudkhah ◽  
Ameneh Shabani
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Thermogravimetric Analysis ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Combustion Method ◽  
Strontium Hexaferrite ◽  
Auto Combustion ◽  
Ft Ir

In this paper, strontium hexaferrite nanoparticles were synthesized by the sol–gel auto-combustion method. Effect of annealing temperature on crystal structure, morphology and magnetic properties of nanoparticles was investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Also, the thermal decomposition of as-synthesized powdered samples has been studied by thermogravimetric analysis (TGA). The XRD patterns confirmed the formation of single phase M-type hexagonal crystal structure for powders annealed above 950[Formula: see text]C, whereas the presence of hematite ([Formula: see text]-Fe2O3) as secondary phase was also observed for sample annealed at 900[Formula: see text]C. Furthermore, the crystallinity along with the crystallite size were augmented with annealing temperature. Comparison of the FT-IR spectra of the samples before and after annealing treatment showed the existence of metal–oxygen stretching modes after annealing. The thermogravimetric analysis confirmed the thermal decomposition of as-burnt powders happened in three-stage degradation process. The TEM images showed the nanoparticles like hexagonal-shaped platelets as the size of nanoparticles increases by increasing the annealing temperature. With increasing annealing temperature, the magnetic saturation and the coercivity were increased to the maximum value of 74.26 emu/g and 5.67 kOe for sample annealed at 1000[Formula: see text]C and then decreased.

scholarly journals Thermal Decomposition Behavior of Melaminium Benzoate Dihydrate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
N. Kanagathara ◽  
M. K. Marchewka ◽  
K. Pawlus ◽  
S. Gunasekaran ◽  
G. Anbalagan
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Effective Activation Energy ◽  
Preexponential Factor ◽  
Effective Activation ◽  
Heating Rates ◽  
Monoclinic System ◽  
Model Free ◽  
Thermal Decomposition Behavior ◽  
Decomposition Behavior

Crystals of melaminium benzoate dihydrate (MBDH) have been grown from aqueous solution by slow solvent evaporation method at room temperature. Powder X-ray diffraction analysis confirms that MBDH crystallizes in the monoclinic system (C2/c). Thermal decomposition behavior of MBDH has been studied by thermogravimetric analysis at three different heating rates: 10, 15, and 20°C/min. Nonisothermal studies of MBDH revealed that the decomposition occurs in three stages. The values of effective activation energy (Ea) and preexponential factor (ln A) of each stage of thermal decomposition for all heating rates were calculated by model free methods: Arrhenius, Flynn-Wall, Friedman, Kissinger, and Kim-Park methods. A significant variation of effective activation energy (Ea) with conversion (α) indicates that the process is kinetically complex. The linear relationship between the A and Ea values was established (compensation effect). Avrami-Erofeev model (A3), contracting cylinder (R2), and Avrami-Erofeev model (A4) were accepted by stages I, II, and III, respectively. DSC has also been performed.

Thermal Analysis and Analytical Pyrolysis of Three Types of Lignin

2017 ◽  
Vol 899 ◽  
pp. 113-118 ◽  
Author(s):  
José Alair Santana Jr. ◽  
Wender Santana Carvalho ◽  
Tiago José Pires de Oliveira ◽  
Carlos Henrique Ataíde
Keyword(s):  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
New Technologies ◽  
Background Information ◽  
Analytical Pyrolysis ◽  
Heating Rates ◽  
Analytical Technique ◽  
Complex Process ◽  
Bio Oil ◽  
Different Types

There is a growing interest in new technologies for power generation, making use of renewable natural resources. Fast pyrolysis is an effective and promising process of thermal decomposition of organic materials. This study evaluated the thermal decomposition of three different types of lignin and investigated the composition of the volatiles formed during the analytical pyrolysis. The thermogravimetric analysis, which is a widely used analytical technique to observe the thermal behavior of materials, was used to investigate the decomposition of the samples at different heating rates. The micropyrolysis is a fast and reliable analytical technique that provides useful background information for development of the complex process production of bio-oil. This study evaluated the composition of the vapor formed during analytical pyrolysis at 450, 550 and 650°C. The curves obtained by thermogravimetric analysis indicate the degradation of all lignin samples takes place in a wide temperature range. Analytical pyrolysis tests for three types of lignin showed formation of phenolic compounds as most significant components.

Water-Resistant Poly(Vinyl Alcohol) Hybrid Nanofibers Incorporating Polyhedral Oligosilsesquioxane (POSS)

2010 ◽  
Vol 89-91 ◽  
pp. 727-732 ◽  
Author(s):  
Byoung Suhk Kim ◽  
Hyo Kyoung Kang ◽  
Myung Seob Khil ◽  
Hak Yong Kim ◽  
Ick Soo Kim
Keyword(s):  
Thermal Decomposition ◽  
Pure Water ◽  
Hydroxyl Group ◽  
Poly Vinyl Alcohol ◽  
Polyhedral Oligosilsesquioxane ◽  
Before And After ◽  
Ft Ir ◽  
Decomposition Behavior ◽  
Nanofiber Mats ◽  
Straightforward Approach

We have explored a straightforward approach for achieving water-resistant properties of the electrospun PVA nanofibers. The electrospun PVA nanofibers are post-treated with a hydrophobic polyhedral oligosilsesquioxane (POSS) hybrid macromer via a direct urethane reaction between the hydroxyl group of PVA and the isocyanate group of POSS macromers. The POSS-modified PVA nanofibers are characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and water resistant property. The morphologies of the electrospun PVA nanofibers before and after POSS post-treatments are regular and a narrow distribution of diameters was observed, indicating a uniform post-treatment of POSS macromers onto the PVA nanofibers. Thermal decomposition behavior of the POSS-modified PVA nanofibers was altered compared to the pure PVA nanofibers, suggesting the suppression of thermal decomposition due to the incorporation of POSS macromers. In addition, the pure PVA nanofiber mats immersed in pure water exhibited no characteristic morphology, whereas the POSS-modified PVA nanofiber mats showed the texture morphology, indicating an enhanced water-resistant property.

Kinetic study of pyrolysis of waste water treatment plant sludge

2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Lukáš Gašparovič ◽  
Ivan Hrablay ◽  
Zuzana Vojteková ◽  
Ľudovít Jelemenský
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Thermogravimetric Analysis ◽  
Sewage Sludge ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Preexponential Factor ◽  
Decomposition Process ◽  
Waste Water Treatment Plant ◽  
Heating Rates

AbstractActivated sewage sludge samples obtained from two different waste water treatment plants were investigated by thermogravimetric analysis. Due to a very high content of water in the sludge samples, these had to be dried at 160°C in an electrical oven in order to remove all adsorbed water. To ensure pyrolysis conditions, nitrogen atmosphere was applied. The pyrolysis decomposition process was carried out in the temperature range from ambient temperature to 900°C at three different heating rates: 2 K min−1, 5 K min−1, 10 K min−1. TGA and DTG curves of the decomposition processes were obtained. Temperature of onset decomposition, final temperature of decomposition, maximum decomposition rate, and decomposition temperature were determined by thermogravimetric analysis for both sludge samples used. The main decomposition process takes place at temperatures in the range from 230°C to 500°C. Above this temperature, there are only small changes in the mass loss which are often attributed to the decomposition of carbonates present in the sewage sludge samples. To determine the apparent kinetic parameters such as the activation energy and the preexponential factor, the so called Friedman isoconversional method was used. Because of the requirements of this method, initial and final parts of the decomposition process, where crossings of the decomposition lines occurred, were cut off. Obtained dependencies of the apparent activation energies and preexponential factors as a function of conversion were used backwards to calculate the modeled decomposition process of sewage sludge and the experimental data were in good accordance with the data obtained by simulation.

scholarly journals Thermogravimetric study on the pyrolysis kinetic mechanism of waste biomass from fruit processing industry

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 4221-4239 ◽  
Author(s):  
Bojan Jankovic ◽  
Milos Radojevic ◽  
Martina Balac ◽  
Dragoslava Stojiljkovic ◽  
Nebojsa Manic
Keyword(s):  
Thermal Decomposition ◽  
Elevated Temperatures ◽  
Agricultural Waste ◽  
Kinetic Mechanism ◽  
Prunus Armeniaca ◽  
Differential Method ◽  
Waste Biomass ◽  
Heating Rates ◽  
Decomposition Reactions ◽  
Comparison Of The Results

The detailed kinetic analysis of slow pyrolysis process of apricot (Prunus armeniaca L.) kernal shells has been estimated, under non-isothermal conditions, through thermogravimetric analysis and derivative thermogravimetry. Thermal decomposition was implemented using four different heating rates (5, 10, 15, and 20?C per minute), with consideration of how this parameter effects on the process kinetics. The higher heating rates provoke the shift of thermoanalytical curves towards more elevated temperatures. Using isoconversional differential method, the variation of activation energy, Ea, with conversion fraction, ?, was detected, and pyrolysis reaction profile was discussed. After resolving the pyrolysis rate curves of individual biomass constituents, the temperature and conversion ranges of their thermal transformations were clearly identified. In the latter stage of analysis, every identified reaction step was considered through mechanistic description, which involves selection of the appropriate kinetic model function. The comparison of the results as well as discrepancies between them has been discussed. The corresponding rate-law equations related to thermal decomposition reactions of all biomass constituents present in the tested agricultural waste material have been identified.

scholarly journals Synthesis, characterization and thermal decomposition of ethyl-2’-amino-5’-cyano-6’-(1H-indole-3yl)-2-oxospiro[indoline-3,4’-pyran]-3’-carboxylate under non‐isothermal condition in nitrogen atmosphere

2019 ◽  
Vol 10 (1) ◽  
pp. 72-81
Author(s):  
Ganesan Nalini ◽  
Natesan Jayachandramani ◽  
Radhakrishnan Suresh ◽  
Prakasam Thirumurugan ◽  
Venugopal Thanikachalam ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Model Fitting ◽  
Isothermal Condition ◽  
Nitrogen Atmosphere ◽  
Single Step ◽  
Heating Rates ◽  
Model Free ◽  
Ft Ir ◽  
Step Mechanism

A new compound, spiro-oxindole derivative compound namely ethyl-2ʹ-amino-5ʹ-cyano-6ʹ-(1H-indole-3yl)-2-oxospiro[indoline-3,4ʹ-pyran]-3ʹ-carboxylate (EACIOIPC) has been synthesized and characterized by microanalysis, FT-IR, mass spectrum and NMR (1H and 13C) techniques. The thermal decomposition of the compound was studied by thermogravimetric analysis under dynamic nitrogen atmosphere at different heating rates of 10, 15, 20 and 30 K/min. The kinetic parameters were calculated using model-free (Friedman’s, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods) and model-fitting (Coats and Redfern (CR)) methods. The decomposition process of EACIOIPC followed a single step mechanism as evidenced from the data. Existence of compensation effect is noticed for the decomposition of EACIOIPC. Invariant kinetic parameters are consistent with the average values obtained by Friedman and KAS in conversional methods.

Preparation of NiO-Ni Nanocomposite by Using of Glutaric Acid in Neutral Condition

2013 ◽  
Vol 829 ◽  
pp. 554-558 ◽  
Author(s):  
Hamid Reza Rahimipour ◽  
Akram Hosseinian
Keyword(s):  
Thermal Decomposition ◽  
Glutaric Acid ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Thermal Decomposition Process ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir ◽  
The Mean ◽  
Ft Ir Spectroscopy

NiO-Ni nanocomposite was synthesized by a conventional sol-gel process. Ni-NiO nanocomposite has been fabricated via the thermal decomposition of nickel salts by using glutaric acid as a spacer agent. A possible mechanism was showed which proposed an optimum temperature to remove nickel impurity from composite in calcinations of nickel glutarate. The produced nanoparticles through the thermal decomposition process were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). The chemical structure of the products was studied by Fourier transform infrared (FT-IR) spectroscopy. The mean crystallite size of the obtained nanosized was estimated to be in the range of 22 nm to 41 nm. The thermal behavior of compound was studied by thermal gravimetric (TG) and differential thermal analyses (DTA).

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