Effect of Biodiesel Unsaturated Fatty Acid on Combustion Characteristics of a DI Compression Ignition Engine

Several researches were carried out on biodiesel combustion, performance and emissions till today. But very few research talks about the chemistry of biodiesel that affects the diesel engine operation. Biodiesel is derived from vegetable oils or animal fats, which comprises of several fatty acids with different chain length and bonding. This paper presents affect of biodiesel molecular weight, structure (Cis and Trans), and number of double bond on diesel engine operation characteristics. For this experiment we have selected three type of biodiesel with different molecular weight and number of double bond. All these three biodiesel selected for our test was prepared and analyzed for fuel properties according to the standard. These biodiesel are tested in a constant speed diesel engine, which developing 4.4 kW power and compared with diesel fuel.