Evaluating Coal–Jatropha curcas Composite Briquettes as Sustainable Fuel Alternatives

Abstract

Coal is a major fuel source but raises environmental concerns. This study investigated the feasibility of utilizing a composite briquette sustainable fuel produced from subbituminous coal and Jatropha curcas biomass. Briquettes were prepared with varying weight ratios of coal to J. curcas biomass (90:0–0:90) using corn starch as a binder. The influence of this ratio on the briquettes’ properties was comprehensively evaluated through proximate analysis, ultimate analysis, scanning electron microscopy (SEM), and X-ray fluorescence (XRF) analysis. The results revealed that increasing the J. curcas content in the briquettes gradually decreased the moisture content, ash content, and fixed carbon content while increasing the volatile matter content. The elemental composition analysis showed a decreasing trend in carbon and sulfur content with increasing J. curcas, while nitrogen and oxygen content increased. The gross calorific value (GCV) exhibited a significant positive correlation with the coal content, reaching a maximum value of 28.29 MJ/kg for briquettes specially composed of J. curcas biomass. These findings suggest that coal–J. curcas briquettes offer a promising alternative fuel source with tailorable properties depending on the desired balance between burning characteristics and calorific value. Further research could explore the combustion behavior and emission profiles of these briquettes to assess their environmental impact.