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.