Interesterification Process of Palm Oil Using Base Catalyst: The Effect of Stirring Speed and Type of Catalyst on Kinetic Energy and Dipole Moment

Abstract

Making biodiesel which has so far been carried out, is a transesterification process with glycerol by-products. Glycerol has a low economic value and is usually only disposed of as waste. An alternative process for producing biodiesel with more valuable by-products is interesterification. The by-product of the interesterification reaction is triacetin which is widely used in the chemical, food, and pharmaceutical industries. The operating conditions of the interesterification reaction were the reaction temperature of 60⁰C, the molar ratio of palm oil: methyl acetate = 1: 6, the reaction time of 1 hour, catalyst type (KOH, NaOH), stirring speed (200, 300, 400, 500, 600 rpm) and catalyst mass (0.25, 0.5, 0.75% wt. oil). From the analysis and calculation, the highest FAME yield was 57.30% at reaction temperature 60⁰C, the molar ratio of palm oil: methyl acetate = 1: 6, reaction time 1 hour, KOH catalyst, stirring speed of 300 rpm, and catalyst mass 0.75% wt oil. From the calculation of ChemDraw software for the triglyceride + methyl acetate + KOH system had a kinetic energy of 3,670 kJ/kmol and a dipole moment of 20,330 debyes, whereas the triglyceride + methyl acetate + NaOH system had a kinetic energy of 2,977 kJ/kmol and a dipole moment of 11,457 debyes so that the KOH catalyst was superior in terms of reactivity and solubility. Biodiesel produced had an acid value of 0.3927 mg KOH/gr and met ASTM D664 for a maximum acid value of 0.5 mg KOH/gr.