Esterification of Palm Fatty Acid Distillate with High Amount of Free Fatty Acids Using Coconut Shell Char Based Catalyst

Abstract

Indonesia, as the biggest palm oil producers and exporters in the world, is producing large amounts of low-grade oil wastessuch as palm fatty acid distillate (PFAD) from palm oil industries. Production of fatty acid methyl ester (FAME) from PFAD that having high amount of free fatty acids (FFA) was studied in this work. Low cost feedstocks such as PFADneed to be utilized to replace edible oils in order to improve the economical feasibility of biodiesel. The esterification of FFAin PFAD with methanol using a coconut shell biochar (CSB) catalyst is a promising method to convert FFA into biodiesel. In this study, the CSBcatalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The physico-characteristics and acid site densities were analyzed by Nitrogen gas adsorption, FT-IR, X-ray fluorescent (XRF), and acid-base back titration methods. The effects of the mass ratio of catalyst to oil (1-7%), the molar ratio of methanol to oil (6:1 to 12:1), and the reaction temperature (40, 50 and 60oC) were studied for the conversion of FFA to optimize the reaction conditions. The optimal conditions were an methanol/PFAD molar ratio of 12:1, the amount of catalyst of 7%wt, and reaction temperature of 60oC.