At the first step, the processed waste fish oil was fed into the system. The existing water in the reaction at higher temperature levels resulted in triglyceride hydrolysis and free fatty acid formation. Free fatty acids neutralized the catalyst led to soap formation. Therefore, it can be implied that the existence of water and free fatty acids caused soap production.
For performing the tests, the catalyst of potassium hydroxide (1%oil weight) and alcohol to oil volumetric ratio of 1:4 was applied. Since waste oil was used for biodiesel production, the color of resulting mixture was dark brown during the early stages of reaction turning to a lighter color at the later phases of the reaction. The reaction was conducted for 2 h at the temperature of 60 C, agitation speed of 300 rpm and at the ambient pressure. The reason for selecting the temperature value of 60 C, was that, the temperature of reaction had to be below the boiling temperature of the methanol (64 C). Biodiesel produced contains no sulfur or particular matter that contributes to air pollution. Sulfur and PM have been responsible for black smoke and sour odor problems commonly attributed to dirty diesel fuel. Biodiesel has greater lubricity than petroleum diesel. After production of biodiesel, some biodiesel standard specifications were measured. It
was noticed that these specifications are matched with international standards (ASTM) (Table1).