Effect of Microwaves on Product Characteristics Biodiesel Products from Soybean Oil

Biodiesel is made through a transesterification reaction between vegetable oil and short chain alcohol with a NaOH catalyst and microwaves. This research uses soybean oil as raw material, aiming to determine the microwave power and optimal concentration of the NaOH catalyst. The volume ratio of methanol and soybean oil is 1:12, with the NaOH catalyst weighed according to the variables. The transesterification reaction was carried out by mixing soybean oil and methanol, then heating using a microwave for 2.5 minutes. After that, the mixture was separated using a separating funnel and left for 2 hours until two layers formed: biodiesel on top and glycerol on the bottom. Biodiesel is washed with distilled water at 40°C, then heated in an oven at 100°C for 1 hour. After cooling, the biodiesel is weighed to calculate the yield and its viscosity and density are measured. The research results show that microwave power and NaOH catalyst concentration affect the quality of the biodiesel produced. The highest yield of 99.8% was obtained at 400 watts of power and a catalyst concentration of 0.5%.