Abstract
In order to optimize reaction parameters of biodiesel production from high free fatty acid Jatropha curcas oil by alkali catalyst-based transesterification process, response surface methodology involving central composite design was applied. The effect of five-level three factors and their reciprocal interactions were studied. A total of 20 experiments were conducted and designed to study the effect of reaction temperature, catalyst quantity, and methanol to oil molar ratio on the biodiesel yield. A second-order polynomial regression model was fitted and found adequate with R2 of 0.9879. The model predicted that the highest yield of methyl ester would be 81.93% at the following optimized conditions: reaction temperature of 61°C, alkali catalyst of 2.06% w/w of oil, and methanol to oil molar ratio of 7.28:1. Using these optimal factors under experimental conditions in three independent replicates, an average of 80.32 ± 0.82% yield was achieved and the value was well within the range predicted by the model.