RESUMO
This study presents the feasibility of converting a non-edible oil source native to the Africa region -croton megalocarpus oil to methyl esters (biodiesel) using sulfated tin oxide enhanced with SiO(2) (SO(4)(2-)/SnO(2)-SiO(2)) as super acid solid catalyst. This study was conducted using design of experiment (DoE), specifically, response surface methodology based on three-variable central composite design (CCD) with alpha (alpha)=2. The reaction parameters studied are: reaction temperature (60-180 degrees C), reaction period (1-3h) and methanol to oil ratio (1:6-1:24). Although the oil was found to contain high free fatty acid, however, yield up to 95% was obtained without any pre-treatment step with the following reaction conditions: 180 degrees C, 2h and 15:1 methanol to oil molar ratio, while keeping constant catalyst concentration and stirring speed at 3 wt.% and 350-360 rpm, respectively.
