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] .

Automated summary

This study successfully prepared an efficient KOH/lateritic clay-based catalyst and found that the catalyst's activity is due to both potassium ferrite and potassium silicate phases. In the presence of ethyl alcohol, the catalyst exhibited high catalytic activity in converting sunflower oil into biodiesel.