MIXED ESTERS FROM HIGH FREE FATTY ACIDS WASTE COOKING OIL USING A HETEROGENEOUS COLUMN SYSTEM

Abstract

A heterogeneous catalytic column packed with Amberlyst 15 was used to evaluate the impact of varying column flow rate and fatty acid to ethanol molar ratio on esters production. The reaction temperature was kept constant at 75 °C and the catalyst mass was fixed at 3 g in all experiments. The highest percentage conversion of 95.2 ± 0.5% was observed at a column flow rate of 0.25 mL/min during esterification of acetic acid when the molar ratio of acetic acid to ethanol was 1:3. Replacing acetic acid with oleic acid into the reaction feed reduced esters yield. Maximum percentage conversion for oleic acid was 43.8±1.3% at a molar ratio of 1:1. When esterification of fatty acids mixture with their respective molar ratios that resulted in maximum percentage conversion individually (1:3 for acetic acid and 1:1 for oleic acid) was carried out, the esters yield was 71±1.7%. FTIR analysis of the feedstock before and after the esterification reaction in the packed catalytic column showed the presence of acetic acid, oleic acid and their respective esters.