Pyrolysis kinetics and synergistic effect in co-pyrolysis of Samanea saman seeds and polyethylene terephthalate using thermogravimetric analyser.

• Co-pyrolysis of Samanea saman (SS) seeds and PET was carried out. • Blends of SS and PET produced lower ash and higher volatiles. • SS and PET blend at 3:1 resulted in higher synergistic effect than 1:1 and 5:1. • SS and PET blend at 3:1 required lower activation energy to start reaction. • Five model-free methods were used to calculate kinetic parameters. • Kinetic data show good agreements with experimental data. This work deals with co-pyrolysis of polyethylene terephthalate (PET) with Samanea saman seeds (SS) to understand the kinetics and synergistic effects between two different feedstocks. SS and PET were blended in different ratios (1:1, 3:1 and 5:1) and iso-conversional models such as Kissinger-Akahira-Sunose (KAS), Friedman method (FM), Starink (ST), Ozawa-Flynn-Wall method (OFW), and Coats-Redfern method (CR) were used to calculate the kinetic parameters. Results substantiate assumed hypothesis that blending of SS and PET at 3:1 provided higher synergistic effect and RMS value, which in turn indicated maximum formation of hot volatiles during pyrolysis. Kinetic analysis confirmed that individual SS and PET required higher activation energy while blended SS and PET at 3:1 ratio required lower activation energy to start the reaction. The thermodynamic and kinetic analysis confirmed that biomass had complex reaction kinetics which depends on reaction rate as well as its order. [ABSTRACT FROM AUTHOR]