Comprehensive study on the thermal decomposition process of waste tobacco leaves and stems to investigate their bioenergy potential: Kinetic, thermodynamic, and biochar analysis

Abstract

This work focuses on understanding the thermal decomposition process of tobacco wastes collected from cigarette factories, further evaluating the potential as bioenergy feedstocks. Thermogravimetric analysis was performed on waste tobacco leaves and stems under air and inert atmosphere. The calculated average activation energy of tobacco leaves is 173.11–173.91 kJ mol−1 (air) and 151.32–151.52 kJ mol−1 (N2), while it is 183.28–185.63 kJ mol−1 (air) and 168.50–168.81 kJ mol−1 (N2) for stems. Combined with kinetic and thermodynamic results, waste tobacco can be considered as a potential bio-feedstock energy source. In addition, the microstructure and structural property of residual biochar after pyrolysis were investigated, which has high carbon content, large specific surface area with abundant porosity, indicating the application potential in catalysis, adsorption, energy storage fields. The work aims to pursue the full re-utilization of tobacco residues from cigarette factories, achieving the effect of recycling and turning waste into treasure.