Various Pre-Treatment Methods to Reduce Free Fatty Acid Content in Non-Edible Vegetable Oils for Biodiesel Production

Abstract

In this work, the efforts were made to reduce high free fatty acid (FFA) content in non-edible karanja and jatropha vegetable oils below 1 mg KOH/g. The process was optimized in terms of amount of sulphuric acid used in pre-treatment of the studied non-edible oils. Various adsorbents like activated carbon, alumina, alumina-silica, calcined alumina and calcined alumina-silica exhibited significant removal of FFA in a single-stage filtration process. Pre-treatment of test oil with calcined alumina-silica as adsorbent was found to be the most appropriate for the removal of free fatty acids. Ultraviolet-visible spectroscopy (UV) analysis showed that the original composition of test oil was not changed after the pre-treatment process.