The effect of vacuum process on biodiesel production from Palm Kernel Fatty Acid Distillate

This study aims to examine the operating pressure effect on the manufacture of biodiesel from Palm Kernel Fatty Acid Distillate (PKFAD) by using para-Toluene Sulfonic Acid (PTSA) catalyst. The operating pressures studied are the vacuum pressures of 70 kPa, 80 kPa, 90 kPa, and 100 kPa, which varied with PTSA concentrations of 5%, 10%, 15%, 20%, 25%, and the molar ratios of methanol and PKFAD are 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. Biodiesel production from PKFAD is carried out with reaction duration of 120 minutes and reaction temperature at 50 0C. The amounts of fatty acids converted to biodiesel are calculated based on the initial acid number and the acid number after the esterification reaction. The results obtained show that a vacuum pressure of 70 kPa to 100 kPa provides a conversion above 96% for all catalyst concentrations and all molar ratios of methanol and PKFAD. The highest conversion of PKFAD to biodiesel of 98.6% is obtained at an operating pressure of 80 kPa, a catalyst concentration of 25%, and the molar ratio of methanol and PKFAD is 10:1. The biodiesel characteristics obtained in this study have met the standards of the American Society for Testing Materials.