Abstract
Neat vegetable oil poses some problems when subjected to prolong use in CI engines. The problems are attributed to its high viscosity and low volatility. The process of transesterification can minimize these problems. In this study, the transesterification of refined palm oil stearin was carried out using methanol and potassium hydroxide, to yield methyl ester or biodiesel. The products were evaluated by comparing physical characteristics of the biodiesel to conventional diesel oil. These characteristics included specific gravity, viscosity, pour point, flash point, fire point and heating value. The biodiesel was then tested in a diesel engine to observe their actual performance and emissions. The test results of various ratios of blended biodiesels were compared with conventional diesel oil through short period engine testing. It was found that the blended biodiesel from refined palm oil stearin at 10% by volume could be used for high speed diesel engine because its viscosity and pour point are in range of standard limit for high speed diesel oil. Biodiesel from refined palm oil stearin has a potential use as an environmentally friendly alternative fuel for existing diesel engines without substantial hardware modifications.