Statistical optimization and kinetic study on biodiesel production from a potential non-edible bio-oil of wild radish

Abstract

The bio-oil extracted from wild radish seeds is non-edible and it still remains an unexplored area in terms of its use as a feedstock for biodiesel. It was extracted from the seeds using mechanical expeller and the oil yield was found to be 46.2 ± 2 wt%. The physical and chemical properties of the extracted oil were analyzed as per AOAC official methods. In this current study, biodiesel was derived by catalytic transesterification reaction. The parameters that influence the processes like methanol to oil molar ratio, catalyst concentration, reaction temperature, and reaction time were optimized. Taguchi statistical method and Analysis of Variance (ANOVA) table were used to understand the effects of the influencing parameters and to optimize the biodiesel yield. Further, it was compared with Box-Behnken Design (BBD) using Response Surface Methodology (RSM). It shows that Taguchi method gave similar results of RSM within a limited number of runs. At optimized condition, the yield of biodiesel was 94.58 wt%. Kinetic studies were also performed for transesterification reaction and it was observed that the reaction follows pseudo-first-order kinetics. The reaction rate constants and activation energy were determined. The physical and chemical properties of the biodiesel were analyzed as per ASTM test methods and compared with ASTM D6751 standard.