Effect of Anode Depth in Synthesis of Biodiesel using the Anodic Plasma Electrolysis Method

Plasma electrolysis is a process of electrolysis that uses a DC current to excite electrons in the electrolyzed solution. The method is very prolific in producing hydroxyl radical (OH•), which is then used to react with methanol and form a methoxyl radical (CH3O•). Methoxyl radical is used to break the bond of triglycerides to form methyl ester (biodiesel) and glycerol. The purpose of this study is to obtain a good quality and quantity of biodiesel by examining the effect of anode depth with a constant contact area where the anode is the spot of plasma formed. The solution used contains Refined, Bleached, and Deodorized Palm Oil and methanol with a molar ratio of 1:24 and a concentration of KOH 1%-wt. The variations of anode depth are 0.5 cm, 1.5 cm, and 3.5 cm below the surface of the solution, with 5 mm as the constant contact area. The results of this research show an improvement in efficiency, as indicated by yield, and the energy consumption of biodiesel synthesis with increasing depth of the anode. The maximum yield was reached at an anode depth of 3.5 cm, which produced 96.09% as a biodiesel yield with 0.039%-vol water content, 0.138 as the acid number, and a specific energy requirement of 0.909 kJ/ml