Evaluation of Kinetic and Thermodynamic Parameters of Pyrolysis and Combustion Processes for Bamboo Using Thermogravimetric Analysis

As a typical forestry waste, bamboo has gained increasing attention for its potential applications. In order to optimize its valorization, understanding the kinetic and thermodynamic parameters of bamboo pyrolysis and combustion is crucial. In this study, thermogravimetric analysis (TGA) was employed to examine bamboo powder's pyrolysis and combustion behaviors under different temperature ramps in nitrogen and air environments, and the kinetic and thermodynamic parameters were evaluated using the Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink (STR) model-free approaches. The main findings are as follows. (1) The thermogravimetry (TG) and derivative thermogravimetry (DTG) (DTG) curves reveal that bamboo pyrolysis occurs in three distinct stages: drying, devolatilization, and carbonization. Similarly, combustion also proceeds through three stages: drying, devolatilization, and char combustion. Notable differences in the temperature ranges of the key stages were observed between pyrolysis and combustion. (2) The activation energies during the oxidative devolatilization stage of combustion are notably lower compared to those during pyrolysis devolatilization. The disparity in activation energy is even more pronounced in the third stage. (3) Thermodynamic analysis shows that the pyrolysis and combustion of bamboo are endothermic and non-spontaneous. It can be stably converted into value-added energy through the pyrolysis or combustion process. This study provides essential data to aid in designing and scaling up the thermochemical conversion processes for bamboo and promote its efficient valorization of bioenergy.