Catalytic Synthesis of Ethyl Ester From Some Common Oils

Abstract

Catalytic conversion of ethanol to fatty acid ethyl esters
(FAEE) was carried out by homogeneous and heterogeneous
transesterification of melon seed, shea butter and neem seed
oils using NaOH, KOH and 5wt%CaO/Al2O3 catalyst systems
respectively. Oil content of the seeds from n-hexane or hot
water extract ranged from 25.0-33.3% and increased in the
order melon seed< shea butter seed < neem seed. The heterogeneous catalyst maintained an optimal activity after 5
cycles of reusable applications and produced higher FAEE of
95.63% than 91.2% and 92.8% obtained with KOH and NaOH
respectively. After purification by distillation of excess ethanol
and neutralisation and separation of the homogeneous catalysts, the FAEE was subjected to qualitative analysis to
determine its potential application as commercial biodiesel
based on international specifications. With the exception of
neem seed oil FAEE that shows high acid value and total ash
content the esters could be used directly or as blend in diesel
engines to give good performance.

Key words: Ethyl ester, synthesis, catalytic activity, common oils, biodiesel potential.