An experimental study on performance and emission characteristics of an IDI diesel engine operating with neat oil-diesel blend emulsion

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Colleges, School and Institutes


Stable neat oil emulsions were prepared and tested in a multi-cylinder engine to assess the exhaust emission and performance characteristics. The heating value of the biofuel-diesel blend emulsion was 16.8% higher than neat rapeseed oil and 6.7% lower than neat diesel fuels. The density of the biofuel emulsions were increased by up to 11% as compared to neat fossil diesel. The engine produced similar power output when emulsified fuels were used instead of fossil diesel. At full load, the thermal efficiency of neat biofuel emulsion was 12% higher than that of fossil diesel. At higher loads, the bsfc of the biofuel blend emulsion was very close to that of fossil diesel. Compared to fossil diesel, emulsified fuels gave slightly higher CO2 emissions. Biofuel and biofuel-diesel blend emulsions produced up to 15% lower NOx emissions. At 100% load, the smoke intensity of biofuel blend emulsion was about 29% lower than neat fossil diesel operation. Emulsified fuels combusted well, and at higher loads produced similar exhaust gas temperatures to those in neat fossil diesel operation. The study concluded that neat oil - diesel - water emulsion fuel could be used in an unmodified diesel engine for increased thermal efficiency and decreased emissions.


Original languageEnglish
Pages (from-to)1041-1050
Number of pages10
JournalRenewable Energy
Early online date29 Jun 2019
Publication statusPublished - Feb 2020


  • Biofuel blend, CI engine, Emission, Emulsification, Performance, Water