CINÉTICA DE PIRÓLISE PARA O SORGO LIGNOCELULÓSICO: ANÁLISE DE DADOS TERMOGRAVIMÉTRICOS PARA APLICAÇÃO DO MODELO DE FRIEDMAN

PYROLYSIS KINETICS FOR LIGNOCELLULOSIC SORGHUM: THERMOGRAVIMETRIC DATA ANALYSIS FOR FRIEDMAN MODEL APPLICATION. Renewable resources are alternatives to fossil fuels and pyrolysis is identified as a process for the generation of biofuel products. The lignocellulosic sorghum is a cereal produced in brazil and it presents several applications, such as the production of second-generation ethanol. The present work aimed to study the slow pyrolysis of lignocellulosic sorghum, the biomass was characterized by means of proximate, ultimate, composition and carbohydrate analyzes. Thermogravimetric analyzes were performed with heating rates between 5 and 25 K min-1 and with N2 atmosphere. The Friedman model allows obtaining the kinetic parameters of biomass decomposition and is widely used due to its simplicity and precision; however, since it is sensitive to experimental noise, an algorithm was developed for the calculation of kinetic parameters for the slow pyrolysis of this biomass, enabling an accurate analysis of the experimental data. The activation energy found by the proposed methodology was 122.65 ± 19.24 kJ mol-1, with determination coefficients above 0.97. The comparison between experimental and theoretical data presented deviation values of 0.934%, 3.408% and 1.101% for heating rates of 5, 10 and 15 K min-1, respectively, showing the accuracy for the determined kinetic parameters.

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Kinetic Study of Waste Wood and Its Carbonization

2002 International Joint Power Generation Conference ◽

10.1115/ijpgc2002-26030 ◽

2002 ◽

Cited By ~ 1

Author(s):

Hoque Md. Mozammel ◽

Masahiro Ota

Keyword(s):

Kinetic Parameters ◽

Thermal Analyses ◽

Least Square ◽

Thermochemical Conversion ◽

Heating Rates ◽

Waste Wood ◽

Exponential Factor ◽

Thermogravimetric Data ◽

Ignition Characteristics ◽

Dta Curves

This study deals with the conversion of waste wood into solid fuel charcoal. Thermogravimetric and differential thermal analyses techniques are used to investigate the kinetics of thermochemical conversion of waste wood. The thermal degradation characteristics and the kinetic parameters (order of reaction, activation energy and pre-exponential factor) are determined at different heating rates using TG/DTA curves. The decomposition of the components could be modeled by an Arrhenius kinetic expression. The kinetic parameters are determined from the thermogravimetric data by a least square technique. The order of reaction and activation of energy vary from 0.41 to 0.52 and 10.86 to 15.10 kJ/mole respectively. Finally attempts are taken to produce charcoal from the waste wood and the charcoals are characterized in respect of yield, electrical conductivity, ESCA (electron spectroscopy for chemical analysis), XRD (x-ray diffraction) and ignition characteristics.

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DETERMINATION OF KINETIC PARAMETERS OF CHEERY TREE PYROLYSIS USING KISSINGER METHOD

Facta Universitatis, Series: Working and Living Environmental Protection ◽

10.22190/fuwlep1903135p ◽

2020 ◽

pp. 135

Author(s):

Milan Protic ◽

Ana Miltojevic ◽

Miomir Raos ◽

Petar Đekić

Keyword(s):

Kinetic Parameters ◽

Fossil Fuels ◽

Chemical Properties ◽

Kinetic Studies ◽

Kissinger Method ◽

Thermochemical Conversion ◽

Heating Rates ◽

Exponential Factor ◽

Reliable Determination

In the global quest for substitution of fossil fuels, biomass is regarded as one of the most promising alternatives. Thermochemical conversion is one of the dominant biomass-to-energy processing routes with pyrolysis as one of the options that gained importance in recent years. In this paper pyrolysis experiments of cheery tree samples were performed. The objective of this research was to determine selected physical and chemical properties of cheery related to thermochemical conversion. The samples were pyrolysed in a thermogravimetric analyzer in an inert, nitrogen, atmosphere at four different heating rates 1, 2, 5 and 10 °C/min. Pyrolysis occurred, as expected, in three step: loss of moisture and light volatiles, active and passive pyrolysis. With an increase in heating rate a lateral shift of the maximum rate of weight loss for the thermal decomposition to higher temperatures was observed, as well as an increase in the amount of residual char. Moreover, kinetic studies were performed using the Kissinger method. The activation energy was calculated to be 155.26 kJ/mol, while the pre-exponential factor was 1.685×1012 min-1. Obtained results are comparable to values reported in literature. Kissinger method is straightforward and offers the possibility for fast and reliable determination of kinetic parameters.

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Modeling of Metalized Food Packaging Plastics Pyrolysis Kinetics Using an Independent Parallel Reactions Kinetic Model

Polymers ◽

10.3390/polym12081763 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1763 ◽

Cited By ~ 1

Author(s):

Samy Yousef ◽

Justas Eimontas ◽

Nerijus Striūgas ◽

Mohammed Ali Abdelnaby

Keyword(s):

Kinetic Model ◽

Kinetic Parameters ◽

Food Packaging ◽

Decomposition Temperature ◽

Gas Chromatography Mass Spectrometry ◽

Pyrolysis Kinetics ◽

Heating Rates ◽

Average Deviation ◽

Exponential Factor ◽

Parallel Reactions

Recently, a pyrolysis process has been adapted as an emerging technology to convert metalized food packaging plastics waste (MFPWs) into energy products with a high economic benefit. In order to upscale this technology, the knowledge of the pyrolysis kinetic of MFPWs is needed and studying these parameters using free methods is not sufficient to describe the last stages of pyrolysis. For a better understanding of MFPWs pyrolysis kinetics, independent parallel reactions (IPR) kinetic model and its modification model (MIPR) were used in the present research to describe the kinetic parameters of MFPWs pyrolysis at different heating rates (5–30 °C min−1). The IPR and MIPR models were built according to thermogravimetric (TG)-Fourier-transform infrared spectroscopy (FTIR)-gas chromatography−mass spectrometry (GC-MS) results of three different types of MFPWs (coffee, chips, and chocolate) and their mixture. The accuracy of the developed kinetic models was evaluated by comparing the conformity of the DTG experimental results to the data calculated using IPR and MIPR models. The results showed that the dependence of the pre-exponential factor on the heating rate (as in the case of MIPR model) led to better conformity results with high predictability of kinetic parameters with an average deviation of 2.35% (with an improvement of 73%, when compared to the IPR model). Additionally, the values of activation energy and pre-exponential factor were calculated using the MIPR model and estimated at 294 kJ mol−1 and 5.77 × 1017 kJ mol−1 (for the mixed MFPW sample), respectively. Finally, GC-MS results illustrated that pentane (13.8%) and 2,4-dimethyl-1-heptene isopropylcyclobutane (44.31%) represent the main compounds in the released volatile products at the maximum decomposition temperature.

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Kinetic Analysis of Low-Rank Coal Pyrolysis by Model-Free and Model-Fitting Methods

Journal of Chemistry ◽

10.1155/2019/9075862 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Qiuli Zhang ◽

Min Luo ◽

Long Yan ◽

Aiwu Yang ◽

Xiangrong Hui

Keyword(s):

Model Fitting ◽

Decomposition Reaction ◽

Low Rank ◽

Coal Pyrolysis ◽

Pyrolysis Kinetics ◽

Heating Rates ◽

Pyrolysis Characteristics ◽

Model Free ◽

Thermal Analyzer ◽

Thermogravimetric Data

Coal SJC, coal WJG, coal ZJM, and coal HCG were selected to investigate the pyrolysis kinetics of northern Shaanxi coals. TG and DSC experiments of four coals were carried out with a synchronous thermal analyzer at heating rates 5, 10, 15, and 20 C/min, respectively. The pyrolysis characteristics were described by thermogravimetric data, and the kinetic parameters were calculated by Flynn–Wall–Ozawa (FWO), Kissinger, general integration, and MacCallum–Tanner methods. The results show that coal SJC, coal ZJM, and coal HCG all conform to the reaction series equation, the thermal decomposition reaction rate is controlled by chemical reaction, and coal WJG conforms to Avrami–Erofeev equation. The activation energies of the four coals are 177.53 kJ/mol, 200.34 kJ/mol, 158.59 kJ/mol, and 240.47 kJ/mol, respectively.

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State-of-the-Art Char Production with a Focus on Bark Feedstocks: Processes, Design, and Applications

Processes ◽

10.3390/pr9010087 ◽

2021 ◽

Vol 9 (1) ◽

pp. 87

Author(s):

Ali Umut Şen ◽

Helena Pereira

Keyword(s):

State Of The Art ◽

Lignocellulosic Materials ◽

Heating Rates ◽

Production Methods ◽

Slow Pyrolysis ◽

Production Studies ◽

Lignocellulosic Feedstocks ◽

Thermochemical Method ◽

Superior Surface ◽

First Time

In recent years, there has been a surge of interest in char production from lignocellulosic biomass due to the fact of char’s interesting technological properties. Global char production in 2019 reached 53.6 million tons. Barks are among the most important and understudied lignocellulosic feedstocks that have a large potential for exploitation, given bark global production which is estimated to be as high as 400 million cubic meters per year. Chars can be produced from barks; however, in order to obtain the desired char yields and for simulation of the pyrolysis process, it is important to understand the differences between barks and woods and other lignocellulosic materials in addition to selecting a proper thermochemical method for bark-based char production. In this state-of-the-art review, after analyzing the main char production methods, barks were characterized for their chemical composition and compared with other important lignocellulosic materials. Following these steps, previous bark-based char production studies were analyzed, and different barks and process types were evaluated for the first time to guide future char production process designs based on bark feedstock. The dry and wet pyrolysis and gasification results of barks revealed that application of different particle sizes, heating rates, and solid residence times resulted in highly variable char yields between the temperature range of 220 °C and 600 °C. Bark-based char production should be primarily performed via a slow pyrolysis route, considering the superior surface properties of slow pyrolysis chars.

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Kinetic Parameters of Nut Shells Pyrolysis

Energies ◽

10.3390/en14030682 ◽

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.

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Investigating the relationship between tack and degree of conversion in DGEBA-based epoxy resin cured with dicyandiamide and diuron

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0340 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Ali Kuliaei ◽

Iraj Amiri Amraei ◽

Seyed Rasoul Mousavi

Keyword(s):

Epoxy Resin ◽

Reaction Order ◽

Theoretical Data ◽

Cure Kinetics ◽

Diglycidyl Ether ◽

Degree Of Conversion ◽

Ozawa Method ◽

Heating Rates ◽

Scanning Calorimetry ◽

Kinetics Of

Abstract The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$ ). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing.

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AN INNOVATE METHOD OF THERMOGRAVIMETRIC DATA ANALYSIS

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/ivkkt.20216403.6348 ◽

2021 ◽

Vol 64 (3) ◽

pp. 24-32

Author(s):

Mihail V. Mal’ko ◽

Sergej V. Vasilevich ◽

Andrey V. Mitrofanov ◽

Vadim E. Mizonov

Keyword(s):

Experimental Data ◽

Thermal Decomposition ◽

Thermogravimetric Analysis ◽

Kinetic Parameters ◽

Calculation Method ◽

Kinetic Calculation ◽

Pyrolysis Mechanism ◽

Total Mass Loss ◽

Thermogravimetric Data ◽

Heavy Tar

The objective of the study is to examine the Coats-Redfern approximation and to propose an innovative kinetic calculation method for the complex process of the heavy tar thermal decomposition under non-isothermal process. The thermal decomposition process was examined using the thermogravimetric analysis. There are several kinetic models proposed to analyze pyrolysis mechanism in terms of the formal reaction. In this manner, the kinetic parameters of the pyrolysis process can be evaluated based on total mass loss (thermogravimetric analysis –TGA). The TGA procedures can be conducted with isothermal or non-isothermal conditions, but the experimental data obtained according to this procedure have to be transformed into appropriate correlation. The obtained results have shown that the reaction takes place within temperature range of 540 K to 700 K and the inductive period of the process is about 224 min. Kinetic parameters were estimated with using of the conventional Coats-Redfern method. A new kinetic calculation method has been designed to provide a less laboriousness of identifications procedures compared with Coats-Redfern approximation and to take into account an induction time of the process. As the outcome of this study, it was shown that the kinetic parameters estimated with using of the proposed model-fitted method gives the more appropriate correlation in comparison with the conventional Coats-Redfern method. The proposed method uses the Coats-Redfern algorithm for evaluation of the reaction mechanism, but the value of the constant rate is defined directly from experimental data on the conversion rate.

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