Low-Carbon Alternative Fuels Toward Sustainable Mobility: Biodiesel Production and Comparative Analysis of Its Blends with Diesel

The current work seeks to explore the viability of generating biodiesel from waste cooking oil as an economically viable waste biomass through the transesterification process and studied different blends with petroleum diesel (B0 to B100). Key fuel characteristics, such as cetane number, acid value, density, calorific value, flash point, and viscosity, were measured. The findings reported that the cetane number slightly increases as biodiesel is mixed with the blend. Moreover, the heating value gradually drops as biodiesel is mixed with diesel: 44.01 MJ/kg for B5, 43.59 MJ/kg for B10, 42.81 MJ/kg for B20, 42.53 MJ/kg for B25, 42.61 MJ/kg for B30, 41.81 MJ/kg for B40, 41.52 MJ/kg for B50, and 39.49 MJ/kg for pure biodiesel (B100). When compared with neat diesel, neat biodiesel indicated a cumulative decrease of approximately 11.4%. The biodiesel’s good quality was confirmed by the gradual drop in sulfur content, which helped to reduce possible emissions, and the total glycerol, which stayed well below standard limits. It was discovered that low to medium blends (B5–B20) provide better combustion and environmental performance while being completely compatible with traditional diesel engines without the need for modification. Although higher blends (B40–B100) have better safety and pollution benefits, their increased viscosity and lower energy content may necessitate slight modifications to engine calibration or fuel injection. Finally, this study reported that biodiesel–diesel blends are a viable, sustainable, and eco-friendly way to lessen dependency on fossil fuels while preserving engine performance. It also offers important information for maximizing blend ratios for emissions compliance and performance.