Abstract: Diesel engines play very vital role in the different sectors like transportation, industrial and agricultural. Depletion of fossil fuel reserves and increased environmental degradation has generated interest in the use of alternative fuels. Vegetable oils are found to be most promising alternative fuels. Since they are renewable fuels, biodegradable, non-toxic and eco-friendly. Above all, they operate in conventional engine just like diesel thereby requires no major engine modifications. In this experimental investigation, potential of blend of 10% sesame oil and 90% diesel as alternative fuel has been evaluated. Engine performance and emission characteristics obtained with this blend is compared with that obtained with pure diesel. But before that, important properties of sesame oil in comparison to diesel were discussed. When blend of sesame oil-diesel is used, slightly higher fuel consumption rate and lower brake thermal efficiency were obtained. Also, lower air-fuel ratio and higher exhaust gas temperature were obtained with blend of sesame oil-diesel. NOx and CO emissions of the engine were found to increase slightly when sesame oil-diesel blend was used. From this experimental investigation, it has been established that sesame oil-diesel can be substituted for diesel as fuel diesel engine without any engine modification.

Keywords: aternative fuel, vegetable oil, sesame oil, blend, performance and emission characteristics.