Response Surface Methodology for Optimization of Biodiesel Production from High FFA Jatropha Curcas Oil

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.

Keywords:

• Jatropha curcas
• Biodiesel
• Response surface methodology
• Central composite design
• Optimization