Effects of black soldier fly biodiesel blended with diesel fuel on combustion, performance and emission characteristics of diesel engine

•Insects are novel energy resources with potential to produce liquid energy used in diesel engine.•Fueled diesel engine with BSF biodiesel and diesel blends.•BSF biodiesel blends show lower smoke emission.•Equivalent fuel consumption of diesel engine was lower when operated with BSF biodiesel blends. The different fuel injection time, fuel injection pressure, fuel types were investigated to achieve low temperature premixed combustion in four-cylinder light-duty diesel engine using a common rail injection system. The two blending proportions of black soldier fly biodiesel (BD) at 10% and 20% BD-diesel blends were compared with pure diesel fuel in the present study. The combustion, performance, and emission of black soldier fly biodiesel were explored and compared with the conventional diesel combustion. Experimental outcomes showed that under low load, early and late injection time can attain low temperature premixed combustion that resulted in prolonged ignition delay and increased heat release rate. It has been observed that equivalent fuel consumption rate of black soldier fly biodiesel was driven higher (245–260 g/kWh) by increasing fuel injection time and fuel injection pressure but lower than pure diesel fuel (255–270 g/kWh). Moreover, an oxide of nitrogen emission rises with early fuel injection time (100–1200 ppm) compared to late fuel injection time (200–300 ppm), whereas the pure diesel fuel has lower emission 900 ppm at early fuel injection time but the rate was similar at late fuel injection time (200 ppm), whereas the early and late fuel injection time can reduce the smoke emission 0.02 l/m than diesel fuel which has smoke emission 0.04 l/m and 0.08 early and late fuel injection time respectively. The low blending ratio 10% BD recorded the reduction in the oxide of nitrogen emission (50%) than 20% BD and similar effects was observed for equivalent fuel consumption. The heat release rate was found to be high in higher fuel injection pressure due to the increase in the proportion of premixed combustion. Furthermore, the oxide of nitrogen emission was increased with the rise of fuel injection pressure, but smoke emission reduced during the process.