Response surface methodological approach for optimization of free fatty acid removal in feedstock

Fatty acid methyl esters, also referred to as biodiesel, have been determined to have a great deal of potential as substitutes for petro-diesel. In order to optimize conversion yield in the biodiesel production process, feedstocks were previously recommended to be anhydrous, with a free fatty acid content of less than 0.5%. In this study, we removed free fatty acid from feedstock through the use of solid catalysts and response surface methodology. In order to optimize free fatty acid removal, response surface methodology was applied to delineate the effects of five-level-four-factors and their reciprocal interactions on free fatty acid removal. A total of 30 individual experiments were conducted, each of which was designed to study reaction temperature, reaction time, catalyst amounts, or methanol amounts. A statistical model was used to estimate that the optimal free fatty acid removal yield would be 100%, under the following optimized reaction conditions: a reaction temperature of 66.96 degrees C, a catalyst amount of 12.66% (w/v), and a reaction time of 37.65 min. Using these optimal factor values under experimental conditions in three independent replicates, an average conversion yield was well achieved within the values predicted by the model.