Abstract:
In order to understand the relationship between the pyrolysis characteristics of herb residues and their composition & structure, the composition structure and chemical composition of 10 typical Chinese planted herb residues were determined, and the pyrolysis weight loss characteristics were carried by the thermogravimetric analyzer. Through the correlation analysis between the characteristics of the feedstock and the pyrolysis process behavior, the physical factors affecting the pyrolysis process of herb residues and the associated coupling mechanism were discussed. Results showed that herb residues were detected with high content of nitrogen and sulfur. The root samples had high cellulose content and the leaf samples had high lignin content. The ability of thermal decomposition to remove volatile matter of leaves, stems, and seeds of herb residue samples were poor, and the activation energy of pyrolysis obtained by Coats-Redfern integration method was basically within 100 kJ/mol. Roots of herb residue samples were easier to devolatile, and the activation energy was higher than 110 kJ/mol. Among them, yam sample had the strongest pyrolysis ability to devolatilize, with the activation energy of 169.83 kJ/mol. The lowest activation energy was obtained in the artemisia annua sample, and the correspongding value was 64.32 kJ/mol. Cellulose and lignin were the two main physical properties affecting pyrolysis devolatilization and activation energy. The content of cellulose and lignin could be used to predict the pyrolysis devolatilization ability and activation energy of herb residues.