Study on alumina supported heterogeneous catalysts for biodiesel production

Abstract

In this work four heterogeneous catalysts were studied first by preparing a γ-alumina catalytic support then by impregnating with acidic and base compounds to gain certain properties needed to catalyze vegetable oils conversion to biodiesel. The resulted new catalytic properties allowed us to simultaneously conduct esterification and transesterification reaction in a single step when waste cooking oils with a high free fatty acid content were converted to biodiesel. The prepared catalysts were thermally and chemically stable and exhibited good catalytic activity when tested in (trans)esterification reactions to yield biodiesel. The effects of catalyst loading, methanol/oil molar ratio and reaction time on biodiesel yield along with catalyst reusability were investigated. The highest biodiesel yield reached was 88.10% at 65oC reaction temperature, 15:1 methanol/oil molar ratio, 5% catalyst loading and 4 h reaction time.