An alternative wood pyrolysis model based on TGA and cone calorimeter tests

• Published in: Thermochimica acta Vol. 731; p. 179646
• Main Authors: ABDO, Mariam, FLITY, Hassan, TERREI, Lucas, ZOULALIAN, André, MEHADDI, Rabah, GIRODS, Pierre, ROGAUME, Yann
• Format: Journal Article
• Language: English
• Published: Elsevier 01.01.2024
• Subjects: Mechanics; Physics; Thermics; Cone calorimeter; Pyrolysis; Modelling; Wood; Thermogravimetric analysis; Kinetic
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2023.179646

Understanding the process of pyrolysis is crucial to achieve continuous progress in the efficient use of wood as a fuel source in various applications. In the literature, a wide range of kinetic models for wood pyrolysis has been introduced, varying from simpler to more complex and predictive. Some of these models are mathematical, with the sole objective of fitting the experimental results. The others are physical models that describe the underlying chemical processes involved in wood thermal degradation, but they tend to be more complex and time-consuming. In our study, a compromise between these two categories of models was established. A new physical and simple kinetic model of wood thermal degradation was proposed. This model was validated using a multi-scale approach. At micro scale, the thermal degradation of wood was studied using thermogravimetric analysis (TGA). TGA experiments were conducted with two wood species, beech and spruce, in an inert atmosphere at five different heating rates. Based on the latter analysis, our kinetic model of wood thermal degradation was established. Its associated kinetic parameters were determined by fitting the experimental mass loss and mass loss rate data. Good agreement was achieved between the experimental and numerical results. At bench scale, tests were performed in a controlled atmosphere chamber placed in front of a cone calorimeter. The thermal degradation of wood was studied at two heat fluxes in an inert atmosphere obtained by a constant argon injection. The kinetic model developed at the micro scale was implemented into a one-dimensional pyrolysis model, taking into account both thermal and mass transfer phenomena within the wood. The validity of the 1D pyrolysis model was established by comparing the numerical results with the mass loss, mass loss rate, and temperature profile measured during cone calorimeter tests.