Experimental Investigation of the Thermal Performance of Coal–Sawdust Fuel Pellets with Varying Biomass Ratios

Abstract

Coal remains a major source of electricity generation; however, its direct combustion poses efficiency and environmental challenges. This study evaluates the thermal performance of coal–sawdust blends prepared in varying mixing ratios, with emphasis on their proximate characteristics, including moisture content, ash content, volatile matter, and fixed carbon. Seven pellet samples (1–7) were produced through mixing coal and sawdust with a resin binder and subsequently subjected to calorimetry tests to determine their calorific values. The results revealed calorific values ranging from 14.85 MJ/kg to 22.07 MJ/kg, demonstrating their potential suitability as alternative fuels for heating applications. The findings indicate that the chemical composition of the blends, particularly volatile matter, ash, fixed carbon, and moisture content, significantly influences their thermal behaviour, including calorific value, ignition time, and combustion rate. Furthermore, the mixing ratios were found to play a critical role in determining the pellets' overall thermal performance. The study suggests that optimizing biomass-to-coal ratios could enhance combustion efficiency, reduce energy costs, and promote more sustainable energy utilization.