Production of Biodiesel by Ethanolic Transesterification of Sunflower Oil on Lateritic Clay- based Heterogeneous Catalyst

Catalysts based on natural and widely available materials have attracted considerable attention for the transesterification reaction of vegetable oils into biodiesel. This work provides a straightforward process for the preparation of efficient KOH/Lateritic clay-based catalysts by wet impregnation followed by calcination. The catalysts were characterized by X-ray fluorescence, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), titration method of Hammet indicator, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The best catalyst was obtained with KOH/LKa mass ratio of 1/1, activated at 400 degrees C for 2 h calcination time. It was shown that the catalytic activity of KOH/Lateritic clay-based catalyst is due to both potassium ferrite (KFeO2) and potassium silicate (K2SiO3) crystalline phases. The catalyst has a high catalytic activity in the conversion of sunflower oil into biodiesel in the presence of ethyl alcohol. The percentage of conversion into ethyl esters of 99.80% was obtained under conditions of 1 h of reaction time at 70 degrees C, 5wt% catalyst loading and an ethyl alcohol/oil molar ratio of 9:1. The KOH/LKa(1/1-400) catalyst afforded reasonable biodiesel yield up to 3 and 4 cycles for respectively 5 and 10 wt% catalyst loading. The physicochemical specification of the biodiesel obtained matches with ASTM D 6571 and EN 14,214 requirements. KOH/LKa(1/)(1-)(400 )catalyst appeared to be promising candidate to replace conventional homogeneous catalysts for biodiesel production as the reaction times are low enough to be practical in batch processes. [GRAPHICS] .