Co-Pyrolysis and Pyrolysis of Corn-Cob Biomass and Waste Plastic: Comprehensive Study Based on Kinetic and Thermodynamic Approach

This study focuses on the utilization of agro-residual corn-cob biomass, waste plastic and the combination of both for pyrolysis reaction using thermal analysis. Circular bioeconomy is assured by closing all the resource materials loops through co-pyrolysis process. The conversion profiles of corn cob pyrolysis at various heating rates reveal a three-stage decomposition process, and plastic waste exhibits single stage degradation. Due to the interaction between the blended materials, additional degradation peaks arise during the co-pyrolysis of waste plastic (PET bottles) and biomass (corn cobs). The apparent activation energy fluctuates in the range of 120-260 kJ/mol with the conversion, according to Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) kinetic methods. Notably, for co-pyrolysis the apparent activation energy is lower (168 kJ/mol using FWO) than the individual biomass (179 kJ/mol using FWO) and plastic (175 kJ/mol using FWO), suggesting a positive synergistic effect during charring. The liquid crude and char product analysis from corn cob pyorlysis through FTIR and XRD confirms the application of the products in energy and chemical processes. The results obtained in this study can be utilized for co-pyrolysis reactor analysis specifically using waste plastic bottles that are accumulating in the environment.