Effects of graphene nanoplatelet addition to jatropha Biodiesel–Diesel mixture on the performance and emission characteristics of a diesel engine

Highlights: • p_max, dp/dθ_max and dQg/dθ_max increased by 6%, 5% and 5%, respectively. • Brake specific fuel consumption decreased by 20%. • NO_x, CO, and UHC reduced by 40%, 60%, and 50%, respectively. • Considerable improvement in all engine performance was achieved at a concentration of 50 mg/L. In this study, the effects of adding graphene nanoplatelets (GNPs) into jatropha methyl ester–diesel blended fuel (20% by volume jatropha methyl ester + 80% diesel; symbolized by JB20) on the performance, combustion, and emission characteristics of a diesel engine were experimentally investigated. The GNPs were added at different concentrations of 25, 50, 75, and 100 mg/L of JB20. These blends were investigated under various engine loads and speeds. The results showed that adding GNPs at 50–75 mg/L of JB20 achieved an increase of 25% in the thermal efficiency and a reduction of 20% in the brake specific fuel consumption compared to those of pure JB20. The peak cylinder pressure, highest rate of pressure rise, and maximum heat release rate were also increased by 6%, 5%, and 5%, respectively. Furthermore, the engine emissions of NO_x, CO, and UHC were reduced by 40%, 60%, and 50%, respectively, at a GNP dosage of 25–50 mg/L. The results showed that the dose level of 50 mg/L had the optimum enhancement in the overall characteristics of engine performance and emissions.