Co-pyrolytic kinetic and interaction mechanisms and products of pineapple rind and low density polyethylene

The complementariness of biomass residues and plastic waste may be leveraged into fuels and other chemicals via co-pyrolysis in order to decrease our dependence on fossil fuels and increase the circularity of waste streams. The co-pyrolysis of pineapple rind (PR) and low density polyethylene (LDPE) was conducted to characterize its kinetic and interaction mechanisms and products. The co-pyrolysis was best elucidated by three stages where synergistic (facilitative) and antagonistic (inhibitory) effects dominated at below and above 495 ℃, respectively. The activation energy requirement was lower for the co-pyrolysis than the individual PR or LDPE. The lowest co-pyrolysis activation energy (129.17 kJ/mol) occurred with the addition of 50% LDPE. F1, F1, F2, and R2 mechanisms best described the co-pyrolytic kinetics of the blend sample with 50% LDPE at four temperatures. The co-pyrolysis inhibited the production of CO2 and promoted the formation of CH4. The production of acids, aldehydes, and ketones fell significantly during the co-pyrolysis. The variation of these compounds improved the quality of pyrolytic oils. The multi-objective optimization based on the best-fit artificial neural network pointed to the range of 550–800 ℃ and 10 ℃/min for the co-pyrolysis of 50% LDPE and 50% PR as the optimal operational conditions. This study provided new and actionable insights into the optimization of the co-pyrolysis of fruit residues and plastic polymers.