Thermal decomposition behaviors and kinetic parameter calculations during common reed and its components pyrolysis

In this study, Phragmites australis (common reed) and its components (leaves and stems), as abundant wetland residues, were selected to explore thermal decomposition behaviors, calculate kinetic parameters, and reveal co-pyrolysis synergistic effects, which aim to demonstrate their feasibility as renewable energy sources. The main pyrolysis process, devolatilization, was observed around 220–410 °C under various heating rates (10–30 °C min−1). Subsequently, isoconversional model-free methods, i.e., Friedman, Kissinger-Akahira-Sunose (KAS), and Average Linear Integral method (ALIM), were employed to calculate the kinetic parameters, which presented great agreements among the activation energy and pre-exponential factor values. Furthermore, pyrolysis of reed mixtures was also conducted to investigate the synergistic effects between the leaves and stems, in conjunction with Artificial Neural Network (ANN) and Principal Components Analysis (PCA). The results revealed that the synergistic effects promoted weight loss behavior through comparing the experimental and calculated results. The developed ANN model predicted the decomposition behavior of reed mixtures based on existing experimental runs, and PCA identified clusters with similar decomposition properties among these reed mixtures and assessed the influence of principal components during co-pyrolysis. Such information provides a multi-faced understanding of pyrolysis and co-pyrolysis process for reed and its components utilization.