Determination of the Thermodynamic Parameters of the Pyrolysis Process of Post-Consumption Thermoplastics by Non-Isothermal Thermogravimetric Analysis

Currently, the pyrolysis process is an important technology for the final treatment of plastic waste worldwide. For this reason, knowing in detail the chemical process and the thermodynamics that accompany cracking reactions is of utmost importance. The present study aims to determine the thermodynamic parameters of the degradation process of conventional thermoplastics (polystyrene (PS), polyethylene terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP) and polyvinyl chloride (PVC)) from the study of their chemical kinetics by thermogravimetric analysis (TG). Non-isothermal thermogravimetry was performed at three heating rates from room temperature to 550 °C with an inert nitrogen atmosphere with a flow of 20 mL min−1. Once the TG data is obtained, an analysis is carried out with the isoconversional models of Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO) in order to determine the one that best fits the experimental data, and with this, the calculation of the activation energy and the pre-exponential factor is performed. The validation of the model was carried out using the correlation factor, determining that the KAS model is the one that best adjusts for the post-consumer thermoplastic degradation process at the three heating rates. With the use of the kinetic parameters, the variation of the Gibbs free energy is determined in each of the cases, where it is necessary that for structures containing aromatic groups a lower energy is presented, which implies a relative ease of degradation compared to the linear structures.

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High thermodynamic stability study of PLA/LCNF composite

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705718779120 ◽

2018 ◽

Vol 32 (8) ◽

pp. 1017-1030

Author(s):

Yang Liu ◽

Zhaodong Ding ◽

Xuejiao Liu ◽

Xuan Wang ◽

Liping Zhang

Keyword(s):

Thermal Degradation ◽

Cellulose Nanofibrils ◽

Model Fitting ◽

Degradation Process ◽

Nitrogen Atmosphere ◽

Stability Study ◽

Poly Lactic Acid ◽

Heating Rates ◽

Isokinetic Relationship ◽

Exponential Factor

Thermal degradation behaviors of one composite constituted by poly(lactic acid) (PLA), cellulose nanofibrils (CNF), and lignin–cellulose nanofibrils (LCNF) in a nitrogen atmosphere were studied using thermogravimetric analysis (TGA). It was found that the thermal degradation stability of the PLA/LCNF composite was improved when compared to PLA and PLA/CNF. The Flynn–Wall–Ozawa method was used to determine the apparent activation energy of the composite samples which was based on a set of TGA data obtained at different heating rates. It was shown that the conversion functions calculated by means of the Coats–Redfern method depend on a set of kinetic models, which could be concluded that using the model-fitting methods couldn’t reveal the complexity of the thermal degradation process and the isokinetic relationship method was used to estimate a model-independent pre-exponential factor (ln A) corresponding to a given degree of conversion.

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INVESTIGATION OF THERMAL DEGRADATION OF POULTRY PROCESSING DEWATERED SLUDGE USING THERMOGRAVIMETRIC ANALYSIS METHOD

Jurnal Teknologi ◽

10.11113/jt.v76.5522 ◽

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.

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Non-isothermal degradation kinetics for polycarbonate/ polymethylphenylsilsesquioxane composites

e-Polymers ◽

10.1515/epoly.2010.10.1.1 ◽

2010 ◽

Vol 10 (1) ◽

Cited By ~ 9

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

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Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

High Performance Polymers ◽

10.1177/0954008317729741 ◽

2017 ◽

Vol 30 (7) ◽

pp. 787-793 ◽

Cited By ~ 4

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.

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Thermal Cure and Ceramization Kinetics of Perhydropolysilazane

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.575-576.81 ◽

2013 ◽

Vol 575-576 ◽

pp. 81-86 ◽

Cited By ~ 1

Author(s):

Feng Ling Ma ◽

Hui Min Qi ◽

Ya Ping Zhu ◽

Xiao Wen Ren ◽

Fan Wang

Keyword(s):

Activation Energy ◽

Weight Loss ◽

Thermogravimetric Analysis ◽

Kinetic Parameters ◽

Nitrogen Atmosphere ◽

Thermal Cure ◽

Exponential Factor ◽

Kinetics Of

The kinetics of the thermal cure and ceramization of preceramic prehydropolysilazane (PHPS) was investigated by thermogravimetric analysis (TGA) under nitrogen atmosphere. The results indicated that the gases captured during the thermal cure and ceramization process of PHPS, which had three main weight loss events. The corresponding kinetic parameters including activation energy, pre-exponential factor and empirical order of the thermal cure and ceramization stages were evaluated by using Ozawa and Kissinger metnods, respectively.

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Thermogravimetric kinetic study of solid recovered fuels pyrolysis

Hemijska industrija ◽

10.2298/hemind171009002r ◽

2018 ◽

Vol 72 (2) ◽

pp. 99-106 ◽

Cited By ~ 7

Author(s):

Milos Radojevic ◽

Martina Balac ◽

Vladimir Jovanovic ◽

Dragoslava Stojiljkovic ◽

Nebojsa Manic

Keyword(s):

Thermal Analysis ◽

Kinetic Parameters ◽

Simultaneous Thermal Analysis ◽

Experimental Tests ◽

Nitrogen Atmosphere ◽

Cement Industry ◽

Thermochemical Conversion ◽

Gravimetric Analysis ◽

Heating Rates ◽

Exponential Factor

In the Republic of Serbia there are significant quantities of coffee and tire wastes that can be utilized as Solid Recovered Fuel (SRF) and used as an additional fuel for co?combustion with coal and biomass in energy production and cement industry sectors. Differences between SRF and base fuel are a cause of numerous problems in design of burners. The objective of this study was to determine the kinetic parameters for the thermochemical conversion of selected SRF using Simultaneous Thermal Analysis (STA). Samples of coffee and tire waste were used for the experimental tests. Thermal analysis was carried out in nitrogen atmosphere at three different heating rates 10, 15 and 20 K/min for each sample, while it was heated from room temperature up to 900?C. Two sample sizes x <0.25 mm and 0.25 < x <0.5 mm of each SRF were used in experiments, in order to obtain reliable Thermal Gravimetric Analysis (TGA) data for estimation of kinetic parameters for SRF pyrolysis. Experimental results were used for determination of pre-exponential factor and activation energy according to methods presented in the literature. Presented research provides valuable data of coffee and tire waste that can be used for the burners design.

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

ChemEngineering ◽

10.3390/chemengineering5030054 ◽

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.

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Thermogravimetric Analysis and Kinetic Study on Catalytic Pyrolysis of Rice Husk Pellet using Its Ash as a Low-cost In-situ Catalyst

International Journal of Renewable Energy Development ◽

10.14710/ijred.2022.41887 ◽

2021 ◽

Vol 11 (1) ◽

pp. 207-219

Author(s):

Wusana Agung Wibowo ◽

Rochim Bakti Cahyono ◽

Rochmadi Rochmadi ◽

Arief Budiman

Keyword(s):

Thermogravimetric Analysis ◽

Rice Husk ◽

Catalytic Effect ◽

Low Cost ◽

Weight Ratio ◽

Nitrogen Atmosphere ◽

Energy Of Activation ◽

Heating Rates ◽

Decomposition Stage ◽

Model Free

The thermogravimetric behaviors and the kinetic parameters of uncatalyzed and catalyzed pyrolysis processes of a mixture of powdered raw rice husk (RRH) and its ash (RHA) in the form of pellets were determined by thermogravimetric analysis at three different heating rates, i.e., 5, 10, and 20 K/min, from 303 to 873 K. This research aimed to prove that the rice husk ash has a catalytic effect on rice husk pyrolysis. To investigate the catalytic effect of RHA, rice husk pellets (RHP) with the weight ratio of RRH:ARH of 10:2 were used as the sample. Model-free methods, namely Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO), were used to calculate the apparent energy of activation ( ). The thermogravimetric analysis showed that the decomposition of RHP in a nitrogen atmosphere could be divided into three stages: drying stage (303-443 K), the rapid decomposition stage (443-703 K), and the slow decomposition stage (703-873 K). The weight loss percentages of each stage for both uncatalyzed and catalyzed pyrolysis of RHP were 2.4-5.7%, 35.5-59.4%, and 2.9-12.2%, respectively. Using the FR, FWO, and KAS methods, the values of for the degrees of conversion (a) of 0.1 to 0.65 were in the range of 168-256 kJ/mol for the uncatalyzed pyrolysis and 97-204 kJ/mol for the catalyzed one. We found that the catalyzed pyrolysis led the to have values lower than those got by the uncatalyzed one. This phenomenon might prove that RHA has a catalytic effect on RHP pyrolysis by lowering the energy of activation.

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Thermal degradation kinetics of oxo-degradable PP/PLA blends

Journal of Polymer Engineering ◽

10.1515/polyeng-2018-0073 ◽

2018 ◽

Vol 39 (1) ◽

pp. 58-67 ◽

Cited By ~ 4

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.

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Comparison of the dehydration kinetics of solid state compounds of 2-methoxybenzylidenepyruvate with some divalent metal ions

Eclética Química ◽

10.1590/s0100-46702010000100001 ◽

2010 ◽

Vol 35 (1) ◽

pp. 7-18

Author(s):

M. Kobelnik ◽

C. A. Ribeiro ◽

D. S. Dias ◽

G. A. Bernabé ◽

M. S. Crespi

Keyword(s):

Activation Energy ◽

Solid State ◽

Nitrogen Atmosphere ◽

Divalent Metal ◽

Point Of View ◽

Conversion Degree ◽

Divalent Metal Ions ◽

Heating Rates ◽

Exponential Factor ◽

Kinetics Of

Divalent metal complexes of ligand 2-methoxybenzylidenepyruvate with Fe, Co, Ni, Cu and Zn as well as sodium salt were synthesized and investigated in the solid state. TG curves of these compounds were obtained with masses sample of 1 and 5mg under nitrogen atmosphere. Different heating rates were used to characterize and study these compounds from the kinetic point of view. The activation energy and pre-exponential factor were obtained applying the Wall-Flynn-Ozawa method to the TG curves. The obtained data were evaluated and the values of activation energy (Ea / kJ mol-1) was plotted in function of the conversion degree (α). The results show that due to mass sample, different activation energies were obtained. The results are discussed mainly taking into account the linear dependence between the activation energy and the pre exponential factor, where was verified the effect of kinetic compensation (KCE) and possible linear relations between the dehydrations steps of these compounds.

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