Computer-aided treatment of thermogravimetric data and calculation of effective kinetic parameters of thermal decomposition processes

1983 ◽  
Vol 28 (1) ◽  
pp. 29-36 ◽  
Author(s):  
A. E. Venger
Author(s):  
Mihail V. Mal’ko ◽  
Sergej V. Vasilevich ◽  
Andrey V. Mitrofanov ◽  
Vadim E. Mizonov

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.


1979 ◽  
Vol 34 (5) ◽  
pp. 661-663 ◽  
Author(s):  
Amedeo Marini ◽  
Vittorio Berbenni ◽  
Giorgio Flor

Abstract The "differential" method of Achar, Brindley and Sharp (ABS) and the "integral" one of Coats and Redfern (CR) are applied to the dehydration of BaBr2-H20 and HCOOLi-H20 and to the thermal decomposition of Pb(SCN)2, and the kinetic parameters so obtained are compared with those deduced isothermally. The results of the ABS method, at the lowest heating rate (q = 1.2 K min — '), agree well with the isothermal ones, whereas the CR method leads to satisfactory results only for the Pb(SCN)2 thermal decomposition (q = 1.2 K min~*). A possible explanation is given.


2013 ◽  
Vol 67 (12) ◽  
Author(s):  
Juma Haydary ◽  
Dalibor Susa

AbstractKinetics of thermal decomposition of aseptic packages (e.g. Tetrapak cartons) and pyrolysis of this waste in a laboratory flow reactor was studied. Three different models for the calculation of the reaction rate and the determination of apparent kinetic parameters of thermal decomposition were used. The first method assumes a two stage thermal decomposition and the kinetic parameters were determined by fitting a derivative thermogravimetric (DTG) curve to experimentally determined thermogravimetric data of whole aseptic cartons. The second method uses kinetic parameters determined by fitting DTG curves to thermogravimetric data of individual components of aseptic packages. The last method was a multi-curve isoconversion method assuming a change of kinetic parameters with the increasing conversion. All types of the determined kinetic parameters were used in a mathematical model for thermal decomposition of mini briquettes made from aseptic packages at the temperature of 650°C. The model calculated also the heat conduction in the particles and it was verified by an independent set of experiments conducted in a laboratory screw type flow reactor.


2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.


2021 ◽  
Vol 7 (3) ◽  
pp. 50
Author(s):  
Emmi Välimäki ◽  
Lasse Yli-Varo ◽  
Henrik Romar ◽  
Ulla Lassi

The hydrogen economy will play a key role in future energy systems. Several thermal and catalytic methods for hydrogen production have been presented. In this review, methane thermocatalytic and thermal decomposition into hydrogen gas and solid carbon are considered. These processes, known as the thermal decomposition of methane (TDM) and thermocatalytic decomposition (TCD) of methane, respectively, appear to have the greatest potential for hydrogen production. In particular, the focus is on the different types and properties of carbons formed during the decomposition processes. The applications for carbons are also investigated.


Sign in / Sign up

Export Citation Format

Share Document