Comparative study on the effect of nanoparticles in ternary fuel blends on combustion, performance, and emissions characteristics of diesel engine

Literature indicated that pure biodiesel is not suitable as a stand-alone fuel for compression ignition engines due to technical and operational conditions. Biodiesel is being utilized as a blended fuel with diesel. The main drawbacks of biodiesel blends are the formation of higher NOx emissions and brake-specific energy consumption due to the lower calorific value of the fuel. Hence, there are efforts to improve the fuel by the incorporation of nanoparticles. The objective of the current manuscript is toexperimentally investigate the effect of adding 50 mg per liter (mg/L) graphene nanoparticles and 5% and 15% ethanol mixed to form ternary blended fuel on the combustion, performance and emissions in diesel engine. In the present work, a single-cylinder, four-stroke, water-cooled naturally aspirated DI diesel engine capable of developing 3.5 kW at 1500 rpm was used for the study. The fuel samples are K20, K15E5, K5E15, K15E5GNP50, and K5E15GNP50, where "K,""E," and "GNP" stand for biodiesel, ethanol, and graphene nanoparticle, respectively and the corresponding number indicate percentage in the overall blend. The result showed that nanoparticles added to ternary fuel blends improve the engine performance meaningfully, and the brake thermal efficiency higher by 2.03% compared to K20 biodiesel blend. K15E5GNP50 blends resulted in an appreciable reduction in CO, UHC, NOx and smoke levels compared to that of other blends. The maximum reduction in NOx and CO level was found to be about 21% compared to neat diesel. Also, the maximum reduction in smoke level was detected to be about 50%, mainly at full-load conditions. It is concluded that graphene nanoparticle-enhanced blends of K15E5GNP50 has improved engine performance and emissions characteristics.