Efficient production of biodiesel from low-cost feedstock using zinc oleate as catalyst

Abstract

In this study, the synthesis of fatty acid methyl esters (FAME) by the transesterification of low-cost feedstock containing 10 and 22 wt.% free fatty acid (FFA), using zinc oleate (ZnOl) as catalyst, was investigated. The performance of the ZnOl salt in the reaction medium was evaluated in terms of activity and stability in the presence of free fatty acids. At 140°C and 2h of reaction time, triglyceride conversion was 100%, FAME yield was close to 95%, and fatty acid conversion was 75.9% and 82.6% for feedstock with 10 and 22 wt.% FFA, respectively. The zinc carboxylic salt was able to catalyze simultaneously the triglyceride transesterification and the fatty acid esterification reactions with high activity and selectivity under moderate operating conditions and slight FAME and triglycerides hydrolysis.