scholarly journals Calculation of Kinetic Parameters of Thermal Decomposition of Forest Waste using the Monte Carlo Technique

2020 ◽  
Vol 24 (1) ◽  
pp. 162-170
Author(s):  
Alok Dhaundiyal ◽  
Laszlo Toth
Keyword(s):  
Activation Energy ◽  
Monte Carlo ◽  
Kinetic Parameters ◽  
Preexponential Factor ◽  
Thermal Conversion ◽  
Inert Atmosphere ◽  
Monte Carlo Technique ◽  
Heating Rates ◽  
Forest Waste ◽  
Distribution Parameters

AbstractThis paper deals with the pyrolysis of forest waste in the presence of an inert atmosphere. Experiments are carried out at different heating rates (5 °C, 10 °C and 15 °C) to determine derivative thermogravimetric behaviour of the material. Unlike the conventional scheme, the Monte Carlo technique is implemented to solve the distributed activation energy model (DAEM). DAEM is transformed into the inverse pyrolysis problem to determine the kinetic parameters of thermal degradation of forest waste. Activation energy, the preexponential factor and the distribution parameters are estimated by introducing the Monte Carlo Technique in the thermal conversion process.

scholarly journals Calculation of Kinetic Parameters of the Thermal Decomposition of Residual Waste of Coniferous Species: Cedrus Deodara

2018 ◽  
Vol 21 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Muammel M. Hanon
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Inert Atmosphere ◽  
Kissinger Method ◽  
Heating Rates ◽  
Cedrus Deodara ◽  
Coniferous Species ◽  
Competitive Reactions

Abstract This paper deals with pyrolysis decomposition of Cedrus deodara leaves with the help of thermogravimetric analysis (TGA). Experiments are performed in the presence of inert atmosphere of nitrogen. Experiments are conducted at three different heating rates of 5 °C∙min-1, 10 °C∙min-1 and 15 °C∙min-1 within temperature range of 35 °C to 700 °C. Arrhenius parameters such as activation energy and frequency factor are estimated by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger. The activation energy and frequency factor calculated by using Kissinger method are 67.63 kJ∙mol-1 and 15.06 . 104 min-1 respectively; whereas the averaged values of the same parameters through FWO and KAS methods are 89.59 kJ∙mol-1 and 84.748 kJ∙mol-1, 17.27 . 108 min-1 and 62.13 . 107 min-1 respectively. Results obtained through Kissinger method represent the actual values of kinetic parameters. Conversely, FWO and KAS methods reflect the apparent values of kinetic parameters, as they are highly influenced by the overlapping of competitive reactions occur during pyrolysis.

scholarly journals Effect of Pyrolysis Atmosphere on the Gasification of Waste Tire Char

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 34
Author(s):  
Przemysław Grzywacz ◽  
Grzegorz Czerski ◽  
Wojciech Gańczarczyk
Keyword(s):  
Activation Energy ◽  
Kinetic Parameters ◽  
Inert Atmosphere ◽  
Argon Atmosphere ◽  
Conversion Degree ◽  
Heating Rates ◽  
Mean Values ◽  
Co2 Gasification ◽  
Gasification Process ◽  
Lower Reactivity

The aim of the study is to assess the influence of the atmosphere during pyrolysis on the course of CO2 gasification of a tire waste char. Two approaches were used: the pyrolysis step was carried out in an inert atmosphere of argon (I) or in an atmosphere of carbon dioxide (II). The examinations were carried out in non-isothermal conditions using a Rubotherm DynTherm thermobalance in the temperature range of 20–1100 °C and three heating rates: 5, 10 and 15 K/min. Based on the results of the gasification examinations, the TG (Thermogravimetry) and DTG (Derivative Thermogravimetry) curves were developed and the kinetic parameters were calculated using the KAS (Kissinger-Akahira-Sunose) and FWO (Flynn-Wall-Ozawa) methods. Additionally, the CO2 gasification of tire chars reaction order (n), was evaluated, and the kinetic parameters were calculated with the use of Coats and Redfern method. Tire waste char obtained in an argon atmosphere was characterized by lower reactivity, which was reflected in shift of conversion and DTG curves to higher temperatures and higher mean values of activation energy. A variability of activation energy values with the progress of the reaction was observed. For char obtained in an argon atmosphere, the activation energy varied in the range of 191.1–277.2 kJ/mol and, for a char obtained in an atmosphere of CO2, in the range of 148.0–284.8 kJ/mol. The highest activation energy values were observed at the beginning of the gasification process and the lowest for the conversion degree 0.5–0.7.

scholarly journals Eriobotrya japonica Lindl. Kernels: Kinetics of Thermal Degradation under Inert Atmosphere Using Model-Free and Fitting Methods

2020 ◽  
Vol 11 (4) ◽  
pp. 11357-11379
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Mass Loss ◽  
Kinetic Parameters ◽  
Inert Atmosphere ◽  
Eriobotrya Japonica ◽  
Heating Rates ◽  
Noticeable Effect ◽  
Exponential Factor ◽  
Model Free

A kinetic study of the pyrolysis process of raw Eriobotrya japonica Lindl. Kernels (RLK) was investigated using a thermogravimetric analyzer. The weight loss was measured in a nitrogen atmosphere. The samples were heated over a range of temperature from 298 K to 873 K with four different heating rates of 5, 10, 15, 20 K min-1. Mass loss (TGA) and derivative mass loss (DTG) measurements indicate that the increase in heating rate has no noticeable effect on the thermal degradation of the RLK. The results obtained from the thermal decomposition process indicate that there are three main stages such as dehydration, active, and passive pyrolysis. TGA curves indicate that active pyrolysis of RLK is between 160 and 450 °C. In this interval, a shoulder followed by a peak exists on the DTG plots. The shoulder corresponds to the decomposition of hemicelluloses, the first peak to that of cellulose. Lignin decomposes through all temperature range. The kinetic parameters such as activation energy and pre-exponential factor were obtained for two degradation steps by isoconversional model-free methods proposed by FWO, KAS, Kissinger, Tang, MKN, and FR, with degradation mode being: f(α)=(1-α)n with n = 1 for FR and g(α)=-Ln(1- α) for the other methods. The activation energy and pre-exponential factor obtained by the Kissinger method are 173 kJ/mol and 1.9×1016 min-1. While for free model methods, the average kinetic parameters calculated are 172-248 kJ.mol-1 and 5,30×1020 for integral methods (FWO, KAS, Tang and MKN) and 190-271 kJ.mol-1 and 1.77×1022 min-1 for differential Fr method. The activation energy decreases in the final stages of the process. The energy required for hemicellulose degradation is lower than that of cellulose. The most probable reaction functions have thus been determined for these two stages by Coats-Redfern and Criado method, leading to greatly improved calculation performance over the entire conversion range. The reaction, second-order F2, describes the pyrolysis reaction models of RLK. With the Arrhenius parameters obtained from the fitting model of CR, we attempt to reconstruct the temperature-dependent mass conversion curves and have resulted in generally acceptable results. Based on the Arrhenius parameter values obtained by Kissinger equation, the changes in entropy, enthalpy and Gibbs free energy, and lifetime predictions have been estimated concerning the thermal degradation processes of RLK.

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.

scholarly journals Kinetic Parameters of Nut Shells Pyrolysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 682
Author(s):  
Tomasz Noszczyk ◽  
Arkadiusz Dyjakon ◽  
Jacek A. Koziel
Keyword(s):  
Kinetic Parameters ◽  
Waste Treatment ◽  
Model Fitting ◽  
Thermal Conversion ◽  
Point Of View ◽  
The European Union ◽  
Heating Rates ◽  
Isothermal Model ◽  
Biomass Residues ◽  
Conversion Point

The European Union created a European Green Deal Program (EGDP). This program aims at a sustainable economy through the transformation of the challenges related to climate and the environment. The main goal of EGDP is climate neutrality by 2050. The increase of alternative biomass residues utilization from various food processing industries and cooperation in the energy and waste management sector is required to meet these expectations. Nut shells are one of the lesser-known, yet promising, materials that can be used as an alternative fuel or a pre-treated product to further applications. However, from a thermal conversion point of view, it is important to know the energy properties and kinetic parameters of the considered biowaste. In this study, the energy and kinetic parameters of walnut, hazelnut, peanut, and pistachio shells were investigated. The results showed that raw nut shells are characterized by useful properties such as higher heating value (HHV) at 17.8–19.7 MJ∙kg−1 and moisture content of 4.32–9.56%. After the thermal treatment of nut shells (torrefaction, pyrolysis), the HHV significantly increased up to ca. 30 MJ∙kg−1. The thermogravimetric analysis (TGA) applying three different heating rates (β; 5, 10, and 20 °C∙min−1) was performed. The kinetic parameters were determined using the isothermal model-fitting method developed by Coats–Redfern. The activation energy (Ea) estimated for β = 5 °C∙min−1, was, e.g., 60.3 kJ∙mol−1∙K−1 for walnut, 59.3 kJ∙mol−1∙K−1 for hazelnut, 53.4 kJ∙mol−1∙K−1 for peanut, and 103.8 kJ∙mol−1∙K−1 for pistachio, respectively. Moreover, the increase in the Ea of nut shells was observed with increasing the β. In addition, significant differences in the kinetic parameters of the biomass residues from the same waste group were observed. Thus, characterization of specific nut shell residues is recommended for improved modeling of thermal processes and designing of bioreactors for thermal waste treatment.

scholarly journals Thermal Degradation Behaviour of Ni(II) Complex of 3,4-Methylenedioxaphenylaminoglyoxime

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emin Karapınar ◽  
Ilkay Hilal Gubbuk ◽  
Bilge Taner ◽  
Pervin Deveci ◽  
Emine Ozcan
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Free Energy ◽  
Thermal Degradation ◽  
Metal Complex ◽  
Kinetic Parameters ◽  
Preexponential Factor ◽  
Degradation Behaviour ◽  
Mechanism Of Decomposition ◽  
Pyrolytic Decomposition

Thermal degradation behaviour of the Ni(II) complex of 3,4-methylenedioxaphenylaminoglyoxime was investigated by TG, DTA, and DTG at a heating rate of 10°C min−1under dinitrogen. The acquired experimental data shows that the complex is thermally stable up to 541 K. The pyrolytic decomposition process occurs by melting metal complex and metal oxide remains as final product. The energies of the reactions involved and the mechanism of decomposition at each stage have been examined. The values of kinetic parameters such as activation energy (E), preexponential factor (A) and thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) are also evaluated.

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 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.

scholarly journals Drug Nanoparticle Stability Assessment Using Isothermal and Nonisothermal Approaches

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Javier Santamaría-Aguirre ◽  
Robert Alcocer-Vallejo ◽  
Mónica López-Fanárraga
Keyword(s):  
Mathematical Model ◽  
Shelf Life ◽  
Kinetic Parameters ◽  
Heterogeneous Systems ◽  
Preexponential Factor ◽  
Storage Conditions ◽  
Isoconversional Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Drug Products

Many drugs are administered in the form of liquid-dispersed nanoparticles. Frequently, one of the overlooked aspects in the development of this drug delivery system is the loss of efficacy and the degradation of the carried drugs. Estimating the shelf life of drug products implies the storage of samples under controlled conditions of temperature and humidity for different periods, ranging from months to years, delaying decisions during development, manufacturing, and commercialization. Adapting well-known isothermal and nonisothermal methods to nanoparticles would allow correlating kinetic parameters obtained in a single mathematical model and predicting the shelf life faster than traditional methods. Unlike the traditional approaches, the isoconversional method (i) considers drug products as heterogeneous systems, without a unique kinetic order, (ii) establishes a maximum percentage of degradation, (iii) assumes the same kinetics for all processes regardless of the conditions, and (iv) includes the influence of humidity by a modification of Arrhenius equation. This method serves in calculating the kinetic parameters and shelf life derived from them, in a few weeks. In the same way, nonisothermal treatments allow obtaining these parameters by differential scanning calorimetry. Samples are subjected to different heating rates to establish the temperature at which the thermal decomposition event occurs and, thus, to calculate in a few days the activation energy and the preexponential factor using the Kissinger method. But this approach has limitations: the isoconversional method does not consider crystalline state of the sample, while nonisothermal method ignores the effect of the storage conditions. Processing nanoparticles for isothermal and nonisothermal treatments would allow accurate and fast prediction of the drug-loaded nanoparticle shelf life correlating parameters obtained using a single mathematical model. The accuracy of the prediction would be assessed by comparison of estimated shelf life versus data coming from traditional stability studies.

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.

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