Pyrolysis of corn cob: physico-chemical characterization, thermal decomposition behavior and kinetic analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sanjay Singh ◽  
Ashish N. Sawarkar
Keyword(s):  
Crop Residues ◽  
Chemical Characterization ◽  
Isoconversional Methods ◽  
Inert Atmosphere ◽  
Agricultural Crop ◽  
Corn Cob ◽  
Heating Rates ◽  
Model Free ◽  
Physico Chemical ◽  
Decomposition Behavior

AbstractBioenergy out of lignocellulosic biomass, especially from agricultural crop residues, is making massive inroads in our quest for sustainable environment. In the present study, detailed physico-chemical characterization, thermal degradation characteristics, and kinetics of pyrolysis of corn cob are reported. Thermogravimetric experiments were performed at different heating rates, such as, 10, 20, and 30 °C/min in an inert atmosphere. Thermogravimetric (TG) and derivative thermogravimetric (DTG) curves inferred the thermal behavior characteristics of corn cob. Significant content of cellulose and hemicellulose put together (76.23%) suggested tremendous potential of corn cob to give enhanced yield of bio-oil through pyrolysis. Maximum mass loss of 61.92% for corn cob was observed in the temperature range of 180–360 °C. The kinetic parameters for pyrolysis of corn cob were determined by employing model-free isoconversional methods like, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, and Starink. Activation energy from FWO (62.44 kJ/mol) and Starink (61.74 kJ/mol) method for pyrolysis of corn cob was found to be in close proximity. The results revealed prospective bioenergy potential of corn cob as a feedstock for pyrolysis process.

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 Analysis of the Thermal Degradation of Recycled Acrylonitrile-Butadiene-Styrene by non-Isothermal Thermogravimetry

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 281 ◽  
Author(s):  
Rafael Balart ◽  
David Garcia-Sanoguera ◽  
Luis Quiles-Carrillo ◽  
Nestor Montanes ◽  
Sergio Torres-Giner
Keyword(s):  
Thermal Degradation ◽  
Kinetic Analysis ◽  
Acrylonitrile Butadiene Styrene ◽  
Isoconversional Methods ◽  
Reaction Model ◽  
Integral Model ◽  
Heating Rates ◽  
Exponential Factor ◽  
Model Free ◽  
Butadiene Styrene

This work presents an in-depth kinetic study of the thermal degradation of recycled acrylonitrile-butadiene-styrene (ABS) polymer. Non-isothermal thermogravimetric analysis (TGA) data in nitrogen atmosphere at different heating rates comprised between 2 and 30 K min−1 were used to obtain the apparent activation energy (Ea) of the thermal degradation process of ABS by isoconversional (differential and integral) model-free methods. Among others, the differential Friedman method was used. Regarding integral methods, several methods with different approximations of the temperature integral were used, which gave different accuracies in Ea. In particular, the Flynn-Wall-Ozawa (FWO), the Kissinger-Akahira-Sunose (KAS), and the Starink methods were used. The results obtained by these methods were compared to the Kissinger method based on peak temperature (Tm) measurements at the maximum degradation rate. Combined Kinetic Analysis (CKA) was also carried out by using a modified expression derived from the general Sestak-Berggren equation with excellent results compared with the previous methods. Isoconversional methods revealed negligible variation of Ea with the conversion. Furthermore, the reaction model was assessed by calculating the characteristic and functions and comparing them with some master plots, resulting in a nth order reaction model with n = 1.4950, which allowed calculating the pre-exponential factor (A) of the Arrhenius constant. The results showed that Ea of the thermal degradation of ABS was 163.3 kJ mol−1, while ln A was 27.5410 (A in min−1). The predicted values obtained by integration of the general kinetic expression with the calculated kinetic triplet were in full agreement with the experimental data, thus giving evidence of the accuracy of the obtained kinetic parameters.

MODEL FREE KINETICS ANALYSIS OF IMPERATA CYLINDRICA (LALANG)

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Olagoke Oladokun ◽  
Arshad Ahmad ◽  
Tuan Amran Tuan Abdullah ◽  
Bemgba Bevan Nyakuma ◽  
Syie Luing Wong
Keyword(s):  
Activation Energy ◽  
Biomass Conversion ◽  
Frequency Factor ◽  
Isoconversional Methods ◽  
Green Energy ◽  
Imperata Cylindrica ◽  
Heating Rates ◽  
Model Free ◽  
Solid Biofuel ◽  
Kinetics Of

This study is the first attempt at investigating the solid state decomposition and the devolatilization kinetics of Imperata cylindrica (lalang) grass termed the “farmer’s nightmare weed” as a potential solid biofuel of the future. Biomass conversion technologies such as pyrolysis and gasification can be utilized for future green energy needs. However an important step in the efficient utilization and process optimizing of biomass conversion processes is understanding the thermal decomposition kinetics of the feedstock. Consequently, thermogravimetric analysis (TGA) of Imperata cylindrica was carried out in the temperature range of 30-1000 °C at four heating rates of 5, 10, 15, and 20 K min-1 using Nitrogen at a flow rate of 20 L min-1 as purge gas. Using the TGA results, the kinetic parameters activation energy (Ea) and pre-exponential frequency factor (ko) of the grass were estimated via the model free or isoconversional methods of Kissinger and Starink. The results obtained for Kissinger model were 151.36 kJ moI-1 and 5.83 x 109 min-1 for activation energy and pre-exponential frequency factor respectively. However, Starink model activation energy and pre-exponential frequency factor were a function of conversion (α) with average values of 159.93 kJ mol-1 and 6.33 x 1022 min-1 respectively. 

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.

Kinetic Studies on the Thermal Synthesis of Fluorapatite: Model Free and Model-Fitting Methods

2018 ◽  
Vol 28 ◽  
pp. 75-89
Author(s):  
Hamid Reza Javadinejad ◽  
Sayed Ahmad Hosseini ◽  
Mohsen Saboktakin Rizi ◽  
Eiman Aghababaei ◽  
Hossein Naseri
Keyword(s):  
Activation Energy ◽  
Model Fitting ◽  
Kinetic Studies ◽  
Isoconversional Methods ◽  
Reaction Model ◽  
Heating Rates ◽  
Thermal Synthesis ◽  
Exponential Factor ◽  
Model Free ◽  
Master Plots

The kinetic study for the synthesis of Fluorapatite has been done using the thermogravimetric technique under non-isothermal conditions and at four heating rates of 5, 10, 15 and 20 °C. Both model free and model-fitting methods were used to investigate kinetic parameters. Calcium oxide, phosphorus pentoxide and calcium fluoride were used as the precursor materials. The activation energy values were calculated through model-fitting and isoconversional methods and were used to predict the reaction model and pre-exponential factor. In this case several techniques were considered such as master plots and compensation effects. The results indicated that the reaction mechanism was chemically controlled with second and third order reaction models in the whole range of conversion which the activation energy varied from 25 to 43 kJ/mol.

Decomposition Kinetics of Switchgrass: Estimating Activation Energy

2014 ◽  
Vol 881-883 ◽  
pp. 726-733
Author(s):  
Gui Ying Xu ◽  
Jiang Bo Wang ◽  
Ling Ping Guo ◽  
Guo Gang Sun
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Apparent Activation Energy ◽  
High Purity ◽  
Isoconversional Methods ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Model Free ◽  
Chemical Utilization ◽  
Kinetics Of

TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass.

scholarly journals Thermal decomposition of a molecular material {N(n-C4H9)4[FeIIFeIII(C2O4)3]}∞ leading to ferrite: A reaction kinetics study

2013 ◽  
Vol 78 (4) ◽  
pp. 523-536 ◽  
Author(s):  
Ashis Bhattacharjee ◽  
Debasis Roy ◽  
Madhusudan Roy ◽  
Arunabha Adhikari
Keyword(s):  
Thermal Decomposition ◽  
Isoconversional Methods ◽  
Reaction Pathways ◽  
Heating Rates ◽  
Model Free ◽  
Molecular Precursor ◽  
Probable Reaction Mechanism ◽  
Mechanism Of Thermal Decomposition ◽  
Rate Of Reaction ◽  
Probable Reaction

A multi-step thermal decomposition of a molecular precursor, {N(n-C4H9)4[FeIIFeIII(C2O4)3}? has been studied using non-isothermal thermogravimetry (TG) measurements in the temperature range 300 to ~800 K at multiple heating rates (5, 10 and 20 K min-1). The thermal decomposition of the oxalate-based complex proceeds stepwise through a series of intermediate reactions. Two different isoconversional methods, namely, improved iterative method and model-free method are employed to evaluate the kinetic parameters: activation energy and rate of reaction, and the most probable reaction mechanism of thermal decomposition is also determined. The different reaction pathways leading to different steps in the TG profile have also been explored which are supplemented by earlier experimental observations of the present authors.

scholarly journals Thermo-kinetics of Forest Waste Using Model-Free Methods

2019 ◽  
Vol 24 (1) ◽  
pp. 1-31 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Abdulrahman Th Mohammad ◽  
Toth Laszlo
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Isoconversional Methods ◽  
Pine Needles ◽  
Kissinger Method ◽  
Heating Rates ◽  
Pinus Roxburghii ◽  
Kinetics Parameters ◽  
Model Free

Thermal behaviour of pine needles (Pinus Roxburghii) is examined through a thermogravimetry technique. The dried samples of pine needles undergo the non isothermal decomposition at temperature range of 308 - 1173 K. The heating rates used for experimental purposes are: 5 °C min-1, 10 °C min-1 and 15 °C min-1. Kinetic parameters of thermal decomposition reactions of pine needles are obtained through the model-free schemes. The estimated values of activation energy and frequency factor derived from Kissinger method are 132.77 kJ mol-1 and 13.15 x107 min-1, respectively. Furthermore, the averaged values of the same kinetics parameters retrieved from the isoconversional methods are 82.38 kJ mol-1 and 74.833 kJ mol-1, 25.42 x1013 min-1 and 13.449 x1010 min-1, respectively. Instead of the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira Sunrose (KAS) schemes, the kinetic parameters derived from the Kissinger method are relatively promising for the thermal decomposition process, since the kinetic parameters are highly affected by intermediate stages and overlapping of the concurrent reaction occurred during pyrolysis.

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.

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