FAME Production from Jatropha curcas Seed Oil via Calcium Oxide Catalyzed Transesterification and its Purification using Acid Activated Bentonite

Abstract

This paper presents the study of transesterification of Jatropha curcas oil (JCO) via environmentally benign process using calcium oxide as heterogeneous catalyst. Response surface methodology (RSM) based on central composite design (CCD) was performed to optimize three reaction variables in this study. The transesterification process variables were reaction time, x 1 (60 minutes-120 minutes), molar ratio of methanol: oil, x 2 (5:1 – 13:1), and amount of catalyst, x 3 (0.5 % –1.50 % of mass fraction). Since water washing method is not suitable to purify CaO synthesized fatty acid methyl esters (FAME), the purification of as-synthesized FAME with acid-activated bentonites to eliminate the remaining calcium was also investigated. It was found that the yield of JCO FAME could reach up to 94.35 % using the following reaction conditions: 79.33 minutes reaction time, 10.41:1 methanol:oil molar ratio and 0.99 % catalyst at reaction temperature 65 o C. Among bentonites used in the purification, 2.5% of H 2 SO 4 -activated bentonite shows a good performance as decalcifying agent for FAME purification. The properties of purified jatropha FAME were comparable to those of diesel and satisfied the international standard.