Synthesis of methyl ester from used cooking oils

Abstract

The methyl ester synthesis from used cooking oils by transesterification was studied. The investigated variables were temperature (15-60ํC), catalyst type (sodium hydroxide and potassium hydroxide), catalyst concentration (0-1.0 wt%), methanol concentration (10-40 wt%), and reaction time (15-90 min). For NaOH as catalyst, the optimum conditions were 25% MeOH, 1.0% NaOH, 30ํC and reaction time of 30 min and the maximum yield was 94.95%. for KOH as catalyst, the optimum conditions were 25% MeOH, 1.0% KOH, 30ํC for reaction time of 30 min and the maximum yield was 91.87%. The % yield of the methyl ester by using NaOH was higher than KOH for all experiments. Comparing physical properties of methyl ester from used cooking oils with standard diesel, it was found that the flash point, viscosity and pour point of methyl ester are significantly different from the diesl No.2, automotive and industrial diesel oil. The amount of methyl laurate, methyl myristate and methyl palmitate in methyl ester product were quantitied by gas chromatography