Experimental investigation of thermal performance, kinetic triplets, and synergistic effect for bamboo-waste plastic (PP & PE) blends using thermogravimetric analyser in N2 atmosphere

Co-pyrolysis of lignocellulosic biomass with other feedstock can improve the pyrolysis process of biomass due to synergistic effect and it also has the potential to minimize the carbon footprint. In India, bamboo is abundantly available which can be considered as a potential source of energy. On the other side, plastic waste management is a major concern. Therefore, co-pyrolysis of bamboo with polyethylene and polypropylene are investigated in a thermogravimetric analyser to investigate the synergistic effect. Experiments are carried out in the temperature range from 298 to 973 K with variable heating rates of 10 to 40 K/min. It is illustrated that the co-pyrolysis of 75% biomass with 25% polypropylene (B75_PP25) and 75% biomass with 25% polyethylene (B75_PE25) exhibit maximum synergistic effect. Model-free methods (Friedman, OFW, and KAS) are used to estimate the kinetic parameters. Minimum average activation energy is estimated for B75_PP25 and B75_PE25 samples from all three kinetic methods. For example, the average activation energy for B75_PP25 and B75_PE25 are 116.7 kJ/mol and 128.05 kJ/mol respectively from KAS method. Finally, the reaction mechanisms are identified using Criado's master plot method. Statement of Novelty: Studies on co-pyrolysis of bamboo and waste plastics are barely reported in the literature. This investigation deals with the kinetics and synergistic behaviour of co-pyrolysis of waste plastics and bamboo from North-Eastern region of India. Additionally, the findings of this study also include the optimum blending ratio of bamboo and waste plastics for the co-pyrolysis process. This investigation would be useful for the researchers in designing and scaling-up the reactor for the thermal treatment of plastic and bamboo.

Automated summary

In India, bamboo is abundant and can be considered as a potential source of energy. This study investigates the co-pyrolysis of bamboo with polyethylene and polypropylene, and finds that the combination of 75% biomass with 25% polypropylene or polyethylene exhibits maximum synergistic effect. The optimum blending ratio of bamboo and waste plastics for the co-pyrolysis process is also determined.