Abstract

In the present investigation, the high viscosity tobacco oil, which has been considered as non-edible oil as a potential alternative fuel for the Compression Ignition Engine (C. I.). Tobacco Methyl Ester (TME) was prepared by transesterification of raw tobacco oil. A two stage transestirification process was developed since tobacco is having higher acidic value. Transesterification was done using NaOH in the presence of sulphuric acid as catalyst and both acid transesterification and base transestirification was performed. Since TME has higher kinematic viscosity, its viscosity has been reduced by blending with neat diesel. The bio-diesel was blended with neat diesel at various volumetric proportions of B₂, B₅ (denoting 2, 5%) .The performance of this alternate fuel was tested by conducting a series of tests on 4 stroke single cylinder 5.2 kW direct injection diesel engine. The engine was run at different loads like full load, ³/₄, ¹/₂, ¹/₄ and no load at various speeds and also at constant speed .The tests were conducted by using neat diesel and also diesel fuel blended with TME The combustion characteristics and exhaust emissions like hydrocarbon (HC), carbon (II) oxide (CO) and nitric oxides (NO) were measured. Torque, brake power, specific fuel consumption was also measured and the test was plotted in the graphs. The physical and chemical specifications like flash point, fire point, density, kinematic viscosity and acid number of TME were established. Significant improvement in engine performance was observed. The specific fuel consumption and the exhaust gas temperature reduced due to the decrease in viscosity of TME. From the properties and engine test results it has been established that at lower percentage of blending, TME has improved the engine performance but at higher percentages of blending, the performance and engine emissions were drastically effected. The results show that the TME can be used as an alternate fuel in diesel engines without any engine modifications.

Key words: TME (Tobacco Methyl Ester), transesterification, diesel blend B_xx.