In the present work, the combustion characteristics of coal particles with varying average specific gravity (ASG) have been reported. Proximate analysis, ultimate analysis, GCV, petrographic analysis and FTIR analysis were carried out to identify variation in coal properties with varying ASG of coal from1.24 to 1.9. Burning profile parameters and combustion indices are evaluated from TGA analysis. Experimental results inferred that with the increase in coal ASG from 1.24 to 1.9 GCV decreased from 7266 kcal/kg to 3741 kcal/kg, heat release rate varied between 1386 kcal/min to 120 kcal/min, burning time increased from 9 to 30 min and vitrinite varied from 58% to 2.5%, liptinite varied from 13.5% to 1.5%, inertinite varied from 19.2% to 65.7%. Differences in the combustion properties were correlated with hydrocarbon functional groups obtained from FTIR analysis and macerals composition further exploration in details with varying ASG of coal. (C) 2021 Elsevier B.V. All rights reserved.