Transesterification of Waste Cooking Oil to Produce Biodiesel Using Acid and Alkaline Catalyst

Fossil oil as a nonrenewable energy resource, with the development of global economy, the need for energy increases continuously. Biodiesel is a renewable and clean energy, which is made by vegetable oil or animal fat and methyl alcohol to produce fatty acid esters. This research shows that waste cooking oil can be used for biodiesel by the means of esterification and transesterification, at the same time waste cooking oil can be reused. Through orthogonal design, the optimum conditions are that at first,using sulfuric acid 5wt% of waste cooking oil as catalyst, the molar ratio of methanol and oil is 30:1, the reaction temperature is 65 degrees C, and the reaction time is 3h; the second step, KOH is used as catalyst, the amount of the KOH is 0.15wt%, the levels of methanol to oil ratio is 25:1, reaction temperature is 60 degrees C, reaction time is 1h. The maximum yield of biodiesel is 93.24wt%.