Using Pithecellobium Dulce seed-derived biodiesel combined with Groundnut shell nanoparticles for diesel engines as a well-advised approach toward sustainable waste-to-energy management

Abstract

The present study dealt with the combined effect of Groundnut shell (GS)-originated nanoparticles and biodiesel derived from Pithecellobium Dulce seed on the performance and emission characteristics of a diesel engine. For the fuel-preparation step, GS nanoparticles were pulverized using ball milling, while Pithecellobium Dulce biodiesel was synthesized by using a transesterification process with the support of a Ni-doped ZnO catalyst prepared by the co-precipitation method, resulting in a 5 % higher yield in comparison with using a conventional KOH catalyst. Moreover, both GS and as-prepared biodiesel were characterized through Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, and Thermogravimetric analysis. Relating to the experimental analysis of the engine characteristics, the obtained results disclosed an increase in brake thermal efficiency and a decrease in brake-specific fuel consumption by adding 100 ppm of GS (G100) nanoparticles to the B20 (20 % Pithecellobium Dulce biodiesel/80 % diesel fuel) compared to B20. More importantly, emissions of HC, CO, and smoke decreased for B20 compared to diesel fuel but a further reduction of the above-mentioned emissions was observed for B20/G100. In contrast, CO2 and NOx emissions increased with B20 and B20/G100 in comparison with diesel fuel. Also, the addition of Groundnut shell nanoparticles with biodiesel enhanced the combustion characteristics such as in-cylinder pressure and heat release rate. Indeed, the order of peak in-cylinder pressure and heat release rate was found to be B20/G100 > B20 > diesel fuel, which can be attributed to reasons such as fuel accumulation, ignition delay, and heating value. Finally, this present study showed a viable approach to replace conventional diesel fuel with biodiesel combined with bio-nanoparticles in an eco-friendly manner and sustainability. Further, the present approach could be suitably applied to diesel engines without any modifications.