Esterification of free fatty acid and oil with fatty acid content over acidic heterogeneous catalyst

Abstract

The esterification of alcohol with high acid content oil was investigate with different acidic heterogeneous catalysts. The methanol, ethanol, glycerol, palmitic acid, oleic acid, Jatropha oil, waste cooking palm oil and mixed refined palm oil with 15 wt.% oleic acid were used as esterification starting materials. The different morphology and pore size of propyl sulfonic functionalized mesoporous silica SBA-15, acid-activated clay and acid-activated pillar bentonite materials were prepared and studied their catalytic activities. The characterization of the synthesized materials was conducted by XRD, nitrogen adsorption, XRF, SEM and TEM analysis. The rope-like propyl sulfonic functionalized SBA-15 catalyst showed highest catalytic activity in case of oleic acid conversion and tri-glyceride yield, due to its high acid amount and surface area. Moreover, an appropriated bentonite treatment could increase acidity, resulting that bentonite catalyst exhibited high methyl oleate yield as 100% and 99% of FFA conversion in the esterification of oleic acid in palm oil with methanol. Finally, the pillar bentonite was successfully prepared and significantly increased the specific surface area 20-fold compared with the parent material. The acid-activated pillar bentonite catalyst provided higher catalytic activity than bentonite parent and commercial acidic resin catalyst.