cSt ∆Hc, THE EFFECT OF PALM BIODIESEL FUEL ON THE

12 throughputs. In addition, while the products are chemically similar to petroleum-derived gasoline and diesel fuel, the removal of oxygen during the thermal processing also removes any environmental benefits of using an oxygenated fuel. It produced some low value materials and, sometimes, more gasoline than diesel fuel [20]. Micro emulsification is the formation of thermodynamically stable dispersion of two usually not miscible liquids, brought about by one or more surfactants. Drop diameters in micro emulsions typically range from 100 to 1000A [18]. Various investigators have studied micro emulsification of vegetable oils with methanol, ethanol or 1-butanol [16]. They arrived at the conclusion that micro emulsions of vegetable oils and alcohols cannot be recommended for long- term use in diesel engines for similar reasons applied to neat vegetable oils. The fuels produced are prone to incomplete combustion, the formation of carbon deposits, and an increase in the viscosity of the lubricating oil. Moreover, micro emulsions display considerably lower volumetric heating values as compared to hydrocarbon-based diesel fuel due to their high alcohol contents [18], and they have been assessed insufficient in terms of cetane number and cold temperature behavior. Dilution of vegetable oils can be accomplished with such materials as diesel fuels, a solvent or ethanol. Most studies concluded that vegetable oilpetrodiesel blends are not suitable for long-term fuelling of direct injection diesel engines. The studies results, yielding engine problems similar to those found for combustion of neat vegetable oils [18, 19]. Another alternative to improve suitability of vegetable oil for diesel engine is by hydrogenating the oil using typical process of commonly found in crude oil refinery. Koyama et al. 2006 Koyama A., Iki H., Iguchi Y. Applicability of Hydrogenated Palm Oil for Automotive Fuels. 16 th Saudi Arabia – Japan Joint Symposium. Dhahran. Saudi Arabia. November 5 – 6. 2006 had tried to directly hydrogenate palm oil at temperature range of 240 o C to 360 o C and pressure of 6 to 10 MPa with catalyst normally used in hydrodesulphurization . They suggested that the product has a better property in term of oxidation stability than palm oil methyl ester. The relatively better in oxidation stability would make it potentially