Very-Low-Heating-Rate Pyrolysis of Spruce Wood Powder: Thermogravimetric Characterization and Kinetic Modeling

Abstract

Wood is a renewable and sustainable construction material whose thermal decomposition involves the different degradation behaviors of its principal lignocellulosic constituents, namely hemicellulose, cellulose, and lignin. Characterizing the kinetics of these reactions is important for predicting the response of wood to elevated temperatures and supporting the wider use of bio-based materials in sustainable engineering applications. This study investigates the pyrolysis behavior of spruce wood powder by thermogravimetric analysis (TGA) under a nitrogen atmosphere. A very low heating rate of 0.5 °C/min was employed to limit thermal lag and temperature gradients within the sample. The resulting thermogravimetric (TG) and derivative thermogravimetric (DTG) curves distinguish the main stages of wood degradation. A three-reaction Arrhenius model was then used to describe the experimentally observed mass evolution, with the kinetic parameters identified through numerical fitting. The predicted TG and DTG responses agree well with the measurements, while the resulting kinetic parameters are generally consistent with values reported for wood pyrolysis in the literature. These findings provide useful kinetic parameters for thermal and fire-performance modeling and contribute to the effective utilization of renewable wood resources in sustainable timber engineering.