Insights into kinetic and thermodynamic analyses of co-pyrolysis of wheat straw and plastic waste via thermogravimetric analysis

This work studied the co-pyrolysis of wheat straw (WS) and polyethylene (PE) via thermogravimetric experiments from room temperature to 1000 °C at various heating rates (10, 20, and 30 °C/min). Thermal behavior revealed that the maximum decomposition of WS, PE, and their blend occurred in three temperature ranges, viz. 250 - 496, 200 - 486, and 200 - 501 °C. Kinetic parameters were determined using model-free isoconversional methods. Activation energy from KAS (163.56, 220.26 and 196.78 kJ/mol for WS, PE, and blend), FWO (165.97, 222.05, 198.86 kJ/mol for WS, PE, and blend), and Starink (163.45, 220.05, 196.46 kJ/mol for WS, PE, and blend) method was estimated. From among various solid-state kinetic models, first-order reaction kinetics and one and two-dimensional diffusion models dominated co-pyrolysis of WS and PE. Thermodynamic parameters confirmed the feasibility of co-pyrolysis of WS and PE while differential thermal analysis signified that endothermic and exothermic reactions occur simultaneously.