Impact of different nano additives on performance, combustion, emissions and exergetic analysis of a diesel engine using waste cooking oil biodiesel

M.S. Gad ^a, Mostafa M. Abdel Aziz ^b, Hatem Kayed ^c,*

a. Mechanical Engineering Department, Faculty of Engineering, Fayoum University, Egypt
         b. Mechanical Engineering Department, Institute of Aviation Engineering and Technology, Giza, Egypt
         c. Mechanical Power Engineering Department, Faculty of Engineering, Cairo University, 12613, Egypt

Abstract: Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methyl ester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles as TiO2, Al2O3 and CNTs were blended with biodiesel blend at different concentrations of 25, 50, and 100 mg/l to enhance the physicochemical fuel characteristics to obtain clean and efficient combustion performance. An experimental setup was incorporated into a diesel engine to investigate the influence of these nano-materials on engine performance, exergy analysis, combustion characteristics and emissions using WCO biodiesel-diesel mixture. Enriching methyl ester mixture with 100 ppm titanium, alumina and CNTs (B20T100, B20A100 and B20C100) increased the thermal efficiency by 4%, 6% and 11.5%, respectively compared to B20.  Biodiesel blending with nano additives B20T100, B20A100 and B20C100 decreased the emissions of CO (11%, 24% and 30%, respectively), HC (8%, 17% and 25%, respectively) and smoke (10%, 13% and 19%, respectively) compared to B20. However, the noticeable increase of NOx was estimated by 5%, 12% and 27% for B20T100, B20A100 and B20C100, respectively. Finally, the results showed the rise in peak cylinder pressure by 5%, 9% and 11% and increase in heat release rate by 4%, 8% and 13% for B20T100, B20A100 and B20C100, respectively. The fuel exergy of B20T100, B20A100 and B20C100 are lower than biodiesel blend B20 by 6.5%, 16% and 23% but the exergetic efficiency are increased by 7%, 19% and 30% at full load about B20.

Keywords: Waste cooking oil (WCO); Nano additives; Engine performance; Exergy; Combustion characteristics; Emissions

https://doi.org/10.1016/j.jppr.2022.04.004