Influence of Moringa oleifera biodiesel–diesel–hexanol and biodiesel–diesel–ethanol blends on compression ignition engine performance, combustion and emission characteristics

Abstract

In the current work, the influences of Moringa oleifera biodiesel–diesel–hexanol and Moringa oleifera biodiesel–diesel–ethanol blends on compression ignition engine characteristics were experimentally investigated. Experiments were conducted on a diesel engine at 0%, 25%, 50%, 75% and 100% load conditions run at a constant speed of 1500 rpm. The results revealed that B90-D5-H5 acquired the lowest BSFC and maximum BTE of 0.375 kg kW⁻¹ h⁻¹ and 28.8%, respectively, and B100 had the highest BSFC of 0.425 kg kW⁻¹ h⁻¹. B90-D5-H5 had the highest cylinder peak pressure of 74 bar at 4°CA aTDC. The maximum heat release rate (HRR) and longer ignition delay (ID) period of 44 J per °CA and 14.4°CA, respectively, were attained in the B90-D5-H5 blend. At 100% load condition, the lowest amount of carbon monoxide (CO) of 0.32% vol. was acquired in the B80-D5-E15 blend. The maximum nitric oxide (NO) emission of 1090 ppm was also acquired in the B80-D5-E15 blend. B100 had the lowest NO of 846 ppm; B80-D5-E15 had the lowest unburned hydrocarbon (UBHC) emission of 34 ppm at 100% load and the lowest smoke opacity of 34%. Biodiesel–diesel–alcohol blends improve engine performance and decrease emissions compared to the conventional diesel. The utilization of biodiesel–diesel–alcohol blends reduces the consumption of diesel. Hence, ethanol and hexanol are recommended as potential alternative additives in biodiesel–diesel blends to improve engine performance and reduce emissions.