ABSTRACT
The current research investigates the utilization of spirulina microalgae biodiesel blends in a naturally aspirated constant speed compression ignition engine with Ce2O3 nanoparticles at the concentration of 50 ppm under diverse engine loading conditions. Blends of microalgae dispersed with neat diesel at the volume of 20% and 40%. A series of tests were conducted to evaluate the combined effects of microalgae and nanoparticles on engine performance, combustion efficiency, and emission characteristics. The study revealed that increasing the microalgae concentration in the diesel fuel resulted in reduced brake thermal efficiency due to less effective atomization and lower calorific value. Surprisingly, the 20% biodiesel blend with nanoparticles exhibited the highest brake thermal efficiency across various engine loads, while the 40% blend showed higher brake specific fuel consumption compared to both the 20% blend and neat diesel, primarily because of its lower heating value necessitating increased fuel consumption. Furthermore, the biodiesel blends led to lower in-cylinder pressure than pure diesel, mainly attributable to suboptimal atomization. In terms of emissions, the utilization of microalgae-based fuel led to a significant reduction in NOx, CO, and smoke emissions, attributed to the lower cylinder temperatures associated with these blends. In conclusion, this study underscores the potential of spirulina microalgae, particularly when combined with nanoparticles at an optimal concentration, as a promising and environmentally friendly alternative for compression ignition engines.
