Thermochemical, kinetic and ash characteristics behaviour of Thar Lignite, agricultural residues and synthetic polymer waste (EVA)

The study aimed to exploit the energy potential of naturally occurring fuels like Thar Lignite (TL), Sugarcane Bagasse (SB), Cotton Stalks (CS) and synthetic copolymer shoe manufacturing waste Ethylene Vinyl Acetate (EVA). Proximate, ultimate, chemical analysis along with Fourier transform infrared (FTIR) were carried out to analyze the compositional and structural differences between the studied fuel samples. Thermochemical decomposition of fuel samples was also evaluated using thermogravimetric analysis (TGA) under dry air conditions. Derivative thermogravimetry (DTG) obtained from TG curves were used to determine the ignition, peak, burnout temperatures along with combustion performance indices. The order of both average and peak rate of conversion (% s(-1)) was found to be; EVA > SB > CS > TL. Kinetic analysis of the samples was performed using Coats Redfern model. The apparent activation energy 'E-a' (kJ mole(-1)) was in the order of SB = 45.7 > EVA = 36.2 > CS = 36.1 > TL = 23.1. X-ray fluorescence (XRF) and ash fusion temperature (AFT) profile analysis of the ash samples was also performed to investigate the possible deposit formation propensity of post combustion residue products, alkali and slagging indices. SB showed the highest propensity towards slagging deposit formations with the order SB > CS > TL > EVA.