Biodiesel Synthesis of Crude Palm Oil By Using Bifunctional Catalyst Sn/Kaolinite and K2CO3

The relatively high content of free fatty acids in crude palm oil inhibits the direct synthesis of biodiesel. The use of a bifunctional solid heterogeneous catalyst allows for simultaneous transesterification-esterification reactions and facilitates the purification of the final product from the reaction mixture. This study aimed to synthesize biodiesel from crude palm oil via the use of a Sn-K/ metakaolinite catalyst in a simultaneous transesterification-esterification reaction. Biodiesel synthesis was carried out using crude palm oil before and after pretreatment. The optimum conditions were determined by the reaction time ( 1–5 hours), reactant molar ratio (1:2, 1:4, 1:6, 1:8, 1:10, 1:12), and catalyst concentration (1, 3, 5 , 7 and 9%) , and the resulting methyl esters were measured for density, viscosity, and free fatty acids and analyzed via GC‒MS . The results obtained indicate that biodiesel synthesis was successfully carried out with completely converted methyl esters via treated crude palm oil. The optimum conditions for the reaction included a reaction time of 3 hours, a catalyst concentration of 5% and a reactant molar ratio of 1:10. The resulting methyl ester product has a density of 0.86 g/mL, a viscosity of 3.02 cSt and a free fatty acid content of 0.059%. The results of the GC‒MS analysis revealed that the dominant methyl ester components were methyl oleate and methyl palmitate. The synthesis of biodiesel from crude palm oil with a Sn-K/ metakaolinite catalyst has been proven to be carried out in simultaneous transesterification-esterification reactions with good catalytic activity.