Purification of red palm biodiesel by using K_2CO_3 based deep eutectic solvent (DES) with glycerol as hydrogen bond donor (HBD)

摘要

In this study, Crude Palm Oil (CPO) was used as raw material to produce biodiesel. The used DPO had 4.77% concentration of free fatty acid (FFA). Pretreatment of raw materials using 85% Posfat Acid. Pretreatment reaction temperature was 80°C and reaction time was 15 minutes. The transesterification process used potassium hydroxide (KOH) and ethanol (C_2H_5OH). Reaction temperature was 70°C, reaction time was 1.5 hours, molar ratio of etanol to DPO was 9:1 and catalyst concentration was 1.2%. Biodiesel washing process using aquadest. The used DES was Potassium Carbonate (K_2CO_3) based DES with glycerol as Hydrogen Bond Donor (HBD). The DES synthesis temperature was 80°C, Stirring time was 1 hour, stirring rate was 300 rpm and molar ratio variation of K_2CO_3: glycerol were 1:5; 1:6 and 1:7. The purification process used n-hexan to disperse biodiesel and used methanol to disperse DES at room temperature, stirring time was 3 hours, stirring rate 300 rpm and settling time was 2 hours. The variables studied were: molar ratio of K_2CO_3: glycerol and, biodiesel:DES ratio effect to purification of biodiesel process. The Gas Chromatography (GC) analysis results shows that purification using DES of K_2CO_3 : glycerol indeed can increase the purity of biodiesel although the trend was inconsistent. The highest purity of red palm biodiesel is achieved by using DES with K_2CO_3 to glycerol ratio of 1:5, and biodiesel to DES ratio 1:3.5 with biodiesel purity of 98.6453%.