Attempt to mitigate marine engine emissions with improved performance by the investigation of alcohol inclusion in sunflower biodiesel-sunflower oil-diesel blend.

The quaternary blends (diesel-biodiesel-vegetable oil-alcohol) offer enormous potential for reducing fossil fuel usage and mitigating air pollution caused by marine diesel engines. Biodiesel and alcohol are alternate fuels possessing high oxygen content, ensuring clean combustion. Vegetable oil is beneficial in saving diesel contribution and increasing engine lubrication. The objective of the present work was to reduce the dependency on conventional diesel and to come up with cleaner fuel that can also improve engine performance. This experimental work aims to lower exhaust emissions by fueling a single-cylinder, four-stroke direct-injection diesel engine with novel quaternary blends comprising diesel (50%), sunflower biodiesel (25%), sunflower oil (5%), and alcohol (20%). In order to develop cleaner fuel than diesel, different quaternary blends were prepared by varying the length of the carbon chain of alcohols in the blends, namely, DBOEth20, DBOProp20, DBOBut20, DBOHep20, and DBODec20. The performance emissions of quaternary blends were tested at varied engine loads from 5 to 20 Nm (full load), while engine speed was fixed at 1800 rpm. The results indicate that DBOProp20 resulted in the lowest fuel consumption and highest thermal efficiency. DBOProp20 reduced CO, NO and smoke emissions by 19.6%, 9.9%, and 85.7%, as compared to diesel. However, DBODec20 succeed in mitigating CO emission by 41.37% at 100% load. DBOBut20 proved to be most promising in reducing UHC emission by a maximum of 71.69% at 100% load. The highest BTE of 10.98% with lowest BSFC of 13.04% was recorded for DBOProp20 at 100% engine load, in comparison to pure diesel.