Comparative evaluation of nanoparticle-enriched Gossypium hirsutum methyl ester blends for enhanced energy, emission, and economic performance in diesel engines

This study examines the comparative effectiveness of different nanoparticles, metal-based (CuO), carbon-based (CNTs), and their composites (CuO-CNTs), in enhancing the energy and environmental characteristics of a diesel engine propelled with Gossypium hirsutum methyl ester (GHME). A high GHME yield of 96% was achieved under optimized transesterification conditions, and its physicochemical properties were comprehensively characterized. A 30% volumetric blend of GHME with plain diesel fuel (PDF), denoted as PDF30GHME, was prepared and enriched with 100 ppm of CuO, CNTs, and CuO-CNT nanocomposites using ultrasonication. The energy, environmental, and economic characteristics of these test fuels was assessed using a standalone research diesel engine. Nanoparticle characterization revealed improved catalytic and thermal properties, enhancing the combustion process and thermal efficiency. The base fuel blend, PDF30GHME, exhibited a 3.9% upsurge in brake-specific fuel consumption and a 6.6% reduction in brake thermal efficiency related to plain diesel. Emission analyses showed reductions in hydrocarbon, carbon monoxide, and smoke opacity emissions by 4.6%, 7.8%, and 6.4%, respectively, although nitrogen oxides (NOx) emissions increased by 2.7%. Nanoparticle-enriched PDF30GHME significantly improved both performance and emission metrics. Carbon-based additives demonstrated superior enhancements in engine performance and emissions reduction, while metal-based additives were particularly effective in minimizing NOx emissions. Economic analysis revealed that CuO-enriched PDF30GHME achieved the highest cost reduction, lowering fuel costs by 5.42%. The CuO-CNT composite emerged as the most promising additive, offering a balanced improvement in performance, emissions, and cost-effectiveness, positioning it as a viable candidate for sustainable and cleaner diesel engine operations. ➢ Optimized GHME blend enriched with nanoparticles boosts engine performance ➢ CuO-CNT composite achieves balanced performance, emissions, and cost benefits ➢ CNTs enhance BTE by 2.6% and reduce HC, CO, and smoke by 22.9%, 14.7%, and 6.2% ➢ CuO minimizes NOx emissions by 12.9%, promoting cleaner combustion ➢ CuO-enriched fuel lowers operational costs by 5.42%, improving economic viability