Investigation of Pyrolysis Characteristics, Reaction Kinetics, and Product Formation During Co-Pyrolysis of Biodegradable Plastic and Kitchen Waste

Due to the widespread utilization of biodegradable plastics (such as polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT)) as alternatives to traditional plastics such as PE and PP, the disposal of the end-of-use biodegradable plastic products mixed with other waste has increasingly become an issue. This study investigated the co-pyrolysis characteristics, kinetic features, product formation, and synergistic effects of common biodegradable plastics (PLA and PBAT) and kitchen waste (KW) at different mass ratios, using TGA-FTIR-GC/MS. The findings revealed that the addition of KW significantly lowered the pyrolysis temperature. For the PLA and KW with a 2:1 mass ratio, the activation energy decreased by approximately 35 kJ/mol compared to PLA pyrolysis alone. The production of lactide increases significantly, while the formation of aldehydes and CO decreases. Moreover, the co-pyrolysis of KW and PBAT reduces the formation of harmful substances such as tetrahydrofuran and cyclopentanone. This study provides valuable insights into the pyrolysis process of mixed biodegradable plastic waste, offering a better approach for the disposal of similar forms of waste and resource recovery scenarios.