The study of the effect of carbon composition of bio-diesel fuels in a diesel engine

The fuel properties of biodiesel and fossil diesel are similar. The parameter of biodiesel can be directly used without any modification, so it is suitable for the use as the substitute fuel of fossil diesel. The carbon of biodiesel mainly distributes in each different kind of fatty acid, and the carbon composition includes different carbon contents, carbon chain lengths, and saturated or unsaturated carbon bonds, biodiesel made of different raw materials has different fatty acid and carbon composition, which will affect engine performance, fuel consumption, the exhaust emissions and the exhaust gas temperature. Therefore, this study utilized different vegetative oil to produce eight kinds of sources of raw materials and make a comparison among them. Due to the average speed of combustion relaxes evenly, and want the premixed combustion phase to postpone and the combustion is completer, so the heat release rate of the late combustion phase is less drastic. As a result of the result shows that biodiesel with shorter carbon chain lengths and more saturated carbon bond can efficiently reduce exhaust emission, smoke, HC, NO_x, and exhaust gas temperature. The engine performance is also quite satisfying.