Kinetic analysis of thermal degradation of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis from timber industry



Document title: Kinetic analysis of thermal degradation of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis from timber industry
Journal: Maderas : ciencia y tecnología
Database:
System number: 000534470
ISSN: 0718-221X
Authors: 1
2
Institutions: 1University of Caxias do Sul Chemical Engineering, Caxias do Sul. Brasil
2University of Caxias do Sul Postgraduate Program in Engineering of Processes and Technologies, Caxias do Sul. Brasil
Year:
Volumen: 23
Country: Chile
Language: Inglés
English abstract Thermal analysis is a powerful tool to predict the composition and thermal stability of different materials. In this work, thermogravimetric analysis of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis was carried out at four different heating rates (5°C·min-1, 10°C·min-1, 20°C·min-1 and 40°C·min-1) in a non-isothermal condition. The degradation kinetics was evaluated based on Flynn-Wall-Ozawa and Criado methods. The half-life time of wood degradation reaction was also studied. The wood thermal degradation process in an oxidizing atmosphere can be divided in dehydration, devolatilization, and combustion. The kinetic results revels apparent activation energy values of 130-240 kJ·mol-1 for Tectona grandis, 150-191 kJ·mol-1 for Marmaroxylon racemosum and 188-205 kJ·mol-1 for Cedrela odorata, when conversion values ranged from 0,1-0,5. The most probable degradation mechanism for wood species studied is a diffusion model based on a three-dimensional diffusion. Cedrela odorata presented the lowest reaction half-life time while Marmaroxylon racemosum showed the highest. On the basis of these results, it can be concluded that Flynn-Wall-Ozawa and Criado methods associated with half-life time of reaction may contribute to better understand the wood degradation before use it in polymer composites.
Keyword: Activation energy,
Criado method,
Flynn-Wall-Ozawa,
Thermogravimetry,
Thermal stability.
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