The Kinetic Analysis of Biomass Burning Based on Two-Component Reaction Model

2012 ◽  
Vol 424-425 ◽  
pp. 1301-1304
Author(s):  
Hong Bo Lu ◽  
Ze Hui Wang ◽  
Yu Xin Ma
Keyword(s):  
Kinetic Analysis ◽  
Heating Rate ◽  
Biomass Burning ◽  
Combustion Process ◽  
Reaction Model ◽  
Experimental Results ◽  
Parallel Reaction ◽  
Heating Rates ◽  
Two Component ◽  
Good Agreement

Combustion of sawdust was studied using Pyris-1TGA thermogravimetric apparatus in the heating rates of 20, 40, 60K/min. The combustion process of sawdust includes three steps: losing water, precipitation and combustion of volatile, and carburization. A bicomponent parallel reaction model is created and used to simulate the combustion process of sawdust under the heating rate of 40K/min. Comparison of simulation and experimental results shows that the fitting curves are in good agreement with the experimental results

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.

scholarly journals A Modified Model for Kinetic Analysis of Petroleum Coke

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Iman Eslami Afrooz ◽  
Dennis Ling Chuan Ching
Keyword(s):  
Activation Energy ◽  
Distribution Function ◽  
Normal Distribution ◽  
Heating Rate ◽  
Reaction Model ◽  
Normal Distribution Function ◽  
Gravimetric Analysis ◽  
Heating Rates ◽  
Shrinking Core ◽  
Volume Reaction

In this study, a nonisothermal kinetics analysis of petcoke was performed at heating rates of 10, 15, and 20°C/min using thermal gravimetric analysis (TGA). The behaviour of petcoke at different gasification stages (dewatering, volatilization, char burning, and burnout) was studied. The effect of heating rate on the activation energy of petcoke gasification was also investigated. The activation energy of petcoke was estimated using different kinetic models that include volume reaction model (VRM), shrinking core model (SCM), random pore model (RPM), Coats and Redfern model (CRM), and normal distribution function (NDF). The NDF model was modified in this study. It was found that the experimental data were best fitted with the modified normal distribution function (MNDF) and SCM. The results also showed that activation energy decreases as heating rate increases, leading to reduction in gasification completion time.

scholarly journals Thermogravimetric Analysis and Kinetics of Mixed Combustion of Waste Plastics and Semicoke

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xiangdong Xing ◽  
Sha Wang ◽  
Qiuli Zhang
Keyword(s):  
Heating Rate ◽  
Combustion Process ◽  
Calculated Data ◽  
Preexponential Factor ◽  
Combustion Characteristic ◽  
Waste Plastics ◽  
Heating Rates ◽  
Characteristic Index ◽  
Carbon Combustion ◽  
Parallel Reactions

The thermogravimetric method was applied to study the combustion characteristics of waste plastics and semicoke mixture at different heating rates with temperature ranging from room temperature to 1173 K. Also, the kinetic parameters of combustion process were also estimated by fitting the experimental data to the calculated data. The results showed that the mixed combustion process of waste plastics and semicoke could be divided into volatile combustion stage and fixed carbon combustion stage. The addition of waste plastics could increase the comprehensive combustion characteristic index (S) and flammability index (C). It showed synergistic effect in the mixed combustion process. When the additive amount of waste plastics was 60%, the S value and C value reached peak point at the heating rate of 20 K/min. The heating rate had a promotion effect on combustion rate. The mixed combustion process of waste plastics and semicoke could be well simulated by the n-order rate model of double parallel reactions. The activation energies E in the first stage of combustion of the mixture were higher than that in the second stage, and the preexponential factor k was opposite. Meanwhile, a marked kinetic compensation effect was presented between the activation energy and the preexponential factor.

scholarly journals Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7564
Author(s):  
Haibo Wan ◽  
Zhen Huang
Keyword(s):  
Thermal Degradation ◽  
Kinetic Analysis ◽  
Model Fitting ◽  
Degradation Process ◽  
Nylon 6 ◽  
Reaction Model ◽  
Heating Rates ◽  
Model Free ◽  
Order Chemical Reaction ◽  
First Order Chemical Reaction

Thermal degradation of nylon-6 tennis string nylon wastes in inert nitrogen and air atmospheres was investigated by means of multiple heating-rate thermogravimetric analyses. The results obtained under the heating rates of 5–20 K/min are compared in terms of degradation feature and specific temperature for two atmospheres. Using nonisothermal data, kinetic analysis was thoroughly conducted using various isoconversional model-free methods, including Starink, Madhusudanan–Krishnan–Ninan, Tang, Coats–Redfern, and Flynn–Wall–Ozawa methods. With these kinetic analysis methods, the activation energy over the entire degradation process was successfully calculated. By means of the model-fitting master-plots method, the first-order chemical reaction model was determined to be the most appropriate mechanism function for describing pyrolysis and oxidative thermal degradation of nylon-6 waste. Using kinetic parameters, satisfactory matching against experimental data resulted using the Coats–Redfern method for both cases. Furthermore, thermodynamic parameters such as changes in entropy, enthalpy, and Gibbs free energy during thermal degradation processes were evaluated.

scholarly journals Biomass burning aerosol heating rates from the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) 2016 and 2017 experiments

2022 ◽  
Vol 15 (1) ◽  
pp. 61-77
Author(s):  
Sabrina P. Cochrane ◽  
K. Sebastian Schmidt ◽  
Hong Chen ◽  
Peter Pilewskie ◽  
Scott Kittelman ◽  
...  
Keyword(s):  
Heating Rate ◽  
Biomass Burning ◽  
Atmospheric Stability ◽  
Single Scattering ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Heating Rates ◽  
Water Vapor Absorption ◽  
Cloud Properties ◽  
Southeastern Atlantic

Abstract. Aerosol heating due to shortwave absorption has implications for local atmospheric stability and regional dynamics. The derivation of heating rate profiles from space-based observations is challenging because it requires the vertical profile of relevant properties such as the aerosol extinction coefficient and single-scattering albedo (SSA). In the southeastern Atlantic, this challenge is amplified by the presence of stratocumulus clouds below the biomass burning plume advected from Africa, since the cloud properties affect the magnitude of the aerosol heating aloft, which may in turn lead to changes in the cloud properties and life cycle. The combination of spaceborne lidar data with passive imagers shows promise for future derivations of heating rate profiles and curtains, but new algorithms require careful testing with data from aircraft experiments where measurements of radiation, aerosol, and cloud parameters are better colocated and readily available. In this study, we derive heating rate profiles and vertical cross sections (curtains) from aircraft measurements during the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) project in the southeastern Atlantic. Spectrally resolved irradiance measurements and the derived column absorption allow for the separation of total heating rates into aerosol and gas (primarily water vapor) absorption. The nine cases we analyzed capture some of the co-variability of heating rate profiles and their primary drivers, leading to the development of a new concept: the heating rate efficiency (HRE; the heating rate per unit aerosol extinction). HRE, which accounts for the overall aerosol loading as well as vertical distribution of the aerosol layer, varies little with altitude as opposed to the standard heating rate. The large case-to-case variability for ORACLES is significantly reduced after converting from heating rate to HRE, allowing us to quantify its dependence on SSA, cloud albedo, and solar zenith angle.

scholarly journals Torrefaction of Straw from Oats and Maize for Use as a Fuel and Additive to Organic Fertilizers—TGA Analysis, Kinetics as Products for Agricultural Purposes

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2064 ◽  
Author(s):  
Szymon Szufa ◽  
Grzegorz Wielgosiński ◽  
Piotr Piersa ◽  
Justyna Czerwińska ◽  
Maria Dzikuć ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Mass Loss ◽  
Kinetic Analysis ◽  
Heating Rate ◽  
Residence Time ◽  
Process Parameters ◽  
Research Work ◽  
Reaction Model ◽  
Organic Fertilizers ◽  
Electrical Furnace

This publication presents research work which contains the optimum parameters of the agri-biomass: maize and oat straws torrefaction process. Parameters which are the most important for the torrefaction process and its products are temperature and residence time. Thermogravimetric analysis was performed as well as the torrefaction process using an electrical furnace on a laboratory scale at a temperature between 250–525 °C. These biomass torrefaction process parameters—residence time and temperature—were necessary to perform the design and construction of semi-pilot scale biomass torrefaction installations with a regimental dryer and a woody and agri-biomass regimental torrefaction reactor to perform a continuous torrefaction process using superheated steam. In the design installation the authors also focused on biochar, a bi-product of biofuel which will be used as an additive for natural bio-fertilizers. Kinetic analysis of torrefaction process using maize and oat straws was performed using NETZSCH Neo Kinetics software. It was found that kinetic analysis methods conducted with multiple heating rate experiments were much more efficient than the use of a single heating rate. The best representations of the experimental data for the straw from maize straw were found for the n-order reaction model. A thermogravimetric analysis, TG-MS analysis and VOC analysis combined with electrical furnace installation were performed on the maize and oat straw torrefaction process. The new approach in the work presented is different from that of current scientific achievements due to the fact that until now researchers have worked on performing processes on oat and maize straws by means of the torrefaction process for the production of a biochar as an additive for natural bio-fertilizers. None of them looked for economically reasonable mass loss ratios. In this work the authors made the assumption that a mass loss in the area of 45–50% is the most reasonable loss for the two mentioned agri-biomass processes. On this basis, a semi-pilot installation could be produced in a further BIOCARBON project step. The kinetic parameters which were calculated will be used to estimate the size of the apparatuses, the biomass dryer, and biomass torrefaction reactor.

scholarly journals Biomass Burning Aerosol Heating Rates from the ORACLES 2016 and 2017 Experiments

2021 ◽  
Author(s):  
Sabrina P. Cochrane ◽  
K. Sebastian Schmidt ◽  
Hong Chen ◽  
Peter Pilewskie ◽  
Scott Kittleman ◽  
...  
Keyword(s):  
Heating Rate ◽  
Biomass Burning ◽  
Atmospheric Stability ◽  
Single Scattering ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Heating Rates ◽  
Water Vapor Absorption ◽  
Cloud Parameters ◽  
Cloud Properties

Abstract. Aerosol heating due to shortwave absorption has implications for local atmospheric stability and regional dynamics. The derivation of heating rate profiles from space-based observations is challenging because it requires the vertical profile of relevant properties such as the aerosol extinction coefficient and single scattering albedo (SSA). In the southeast Atlantic, this challenge is amplified by the presence of stratocumulus clouds below the biomass burning plume advected from Africa, since the cloud properties affect the magnitude of the aerosol heating aloft, which may in turn lead to changes in the cloud properties and life cycle. The combination of spaceborne lidar data with passive imagers shows promise for future derivations of heating rate profiles and curtains, but new algorithms require careful testing with data from aircraft experiments where measurements of radiation, aerosol and cloud parameters are better collocated and readily available. In this study, we derive heating rate profiles and curtains from aircraft measurements during the NASA ObseRvations of CLouds above Aerosols and their intEractionS (ORACLES) project in the southeastern Atlantic. Spectrally resolved irradiance measurements and the derived column absorption allow for the separation of total heating rates into aerosol and gas (primarily water vapor) absorption. The nine cases we analyzed capture some of the co-variability of heating rate profiles and their primary drivers, leading to the development of a new concept: The Heating Rate Efficiency (HRE; the heating rate per unit aerosol extinction). The HRE, which accounts for the overall aerosol loading as well as vertical distribution of the aerosol layer, varies little with altitude as opposed to the standard heating rate. The large case-to-case variability for ORACLES is significantly reduced after converting from heating rate to HRE, allowing us to quantify its dependence on SSA, cloud albedo, and solar zenith angle.

scholarly journals Kinetic analysis of the termal decomposition of colombian vacuum residua by termogravimetry

2015 ◽  
Vol 35 (3) ◽  
pp. 19-26 ◽  
Author(s):  
Fabian Andrey Diaz Mateus ◽  
Arlex Chaves ◽  
Maria Paola Maradei ◽  
David Alfredo Fuentes ◽  
Alexander Guzman ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Analysis ◽  
Reaction Order ◽  
Calculated Data ◽  
Reaction Model ◽  
Vacuum Residue ◽  
Font Size ◽  
Heating Rates ◽  
Thermogravimetric Analyzer ◽  
Single Reaction

<p style="margin: 0cm 0cm 0pt; text-align: justify; line-height: normal;"><span style="letter-spacing: -0.1pt; font-family: 'Century Gothic','sans-serif'; font-size: 8pt; mso-bidi-font-size: 9.5pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-fareast-language: ES; mso-bidi-language: EN-US;">Five different Colombian vacuum residues were thermally decomposed in a thermogravimetric analyzer. Three heating rates were employed to heat the sample up to 650°C. The kinetic analysis was performed by the Coats-Redfern method to describe the non-isothermal pyrolysis of the residua, a reaction model where the reaction order gradually increases from first to second order is proposed and an excellent agreement of the experimental with the calculated data is presented. The results also indicate that the pyrolysis of a vacuum residue cannot be modeled by a single reaction mechanism.</span></p>

scholarly journals Multistage kinetic analysis of DMAA/MBAM polymer removal from gelcast ceramic parts using a multi-stage parallel reaction model and model-free method

RSC Advances ◽  
2019 ◽  
Vol 9 (47) ◽  
pp. 27305-27317 ◽  
Author(s):  
Jing Li ◽  
Jindi Huang ◽  
Ruiming Yin
Keyword(s):  
Kinetic Analysis ◽  
Reaction Mechanisms ◽  
Reaction Model ◽  
Parallel Reaction ◽  
Model Free ◽  
Multi Stage

This work aims to develop an effective method to investigate the multistage debinding kinetics and the reaction mechanisms of removing DMAA/MBAM polymer from gelcast ceramic parts.

scholarly journals Determination of Thermodynamic Parameters of Polylactic Acid by Thermogravimetry under Pyrolysis Conditions

2021 ◽  
Vol 11 (21) ◽  
pp. 10192
Author(s):  
Paul Palmay ◽  
Melissa Mora ◽  
Diego Barzallo ◽  
Joan Carles Bruno
Keyword(s):  
Activation Energy ◽  
Heating Rate ◽  
Thermodynamic Parameters ◽  
Polylactic Acid ◽  
Reaction Model ◽  
Raw Material ◽  
Heating Rates ◽  
Statistical Validation ◽  
Exponential Factor ◽  
Degradation Temperature

In the present study, the thermodynamic parameters of Polylactic Acid (PLA) under conditions of thermal degradation were determined. The PLA material, previously sampled and characterized, was analyzed by dynamic thermogravimetry (TG) at heating rates of 5, 10 and 15 °C min−1 with a nitrogen flow of 20 mL min−1 from a temperature of 25 to 900 °C. The data were treated using isoconversional kinetic models to obtain the activation energy and the pre-exponential factor of each model. To fit the DTG curves, the Arrhenius equation was used applying the Contraction Sphere reaction model: two-dimensional phase limit reaction (R2). The thermodynamic parameters such as enthalpy, Gibbs free energy and entropy were determined from the kinetic parameters of suitable models for each heating rate after statistical validation and comparison with other studies. The results showed that as the heating rate increases, the degradation temperature also increases, while the activation energy, enthalpy and pre-exponential factor decrease. According to the value of ∆G (171.65 kJ mol−1), PLA has a significant potential to be used as a raw material to produce bioenergy/biofuels by pyrolysis.

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