Ultrasound assisted interesterification for biodiesel production from palm oil and methyl acetate: Optimization using RSM

High energy demand in the industrial world and pollution problems caused by the use of fossil fuels causes the need for the latest innovations that will replace the use of non-renewable energy. One of them is the replacement of diesel fuel with biodiesel. At present biodiesel production uses a transesterification reaction which produces a side product in the form of glycerol. However, the presence of glycerol is considered waste and has no economic value so a separation process is needed. So to eliminate the by-product separation process, a new route is used. This route is called interesterification, using methyl acetate instead of methanol which later produces triacetin as a by-product. Triacetin is recognized as an additive in biodiesel which functions as an anti- knocking in diesel engines. In this research, an interesterification study was carried out by ultrasound and a potassium methoxide catalyst was used to increase the reaction rate and the yield of biodiesel. The operating parameters used include the reactant molar ratio of 1:3; 1:6 and 1:9, catalyst concentration 0.5%; 1.0%; and 1.5%, and reaction times 5, 10, and 15 minutes. The parameter optimization is carried out by the central composite design (CCD) method to reduce the number of experiments needed and also to evaluate various variables and their interactions. The optimal operating conditions are the molar ratio of methyl acetate to palm oil of 8.95, catalyst concentration of 1.44%, and interesterification time of 10.03 minutes can produce the yield of biodiesel of 99.66%.