Antioxidant Evaluation of Extracts of Pecan NutShell (Carya illinoensis) in Soybean Biodiesel B100

Abstract

Biodiesel is subject to radical reactions that promote degradation. To decrease the speed of these degradation reactions and increase oxidative stability, either natural or synthetic antioxidants are added to biodiesel. Thus, the objective of this study is to evaluate the effect of extracts of pecan nutshell (Carya illinoensis) as natural antioxidants derived from biomass using water, ethanol, and methanol/water (50/50) as a solvent for extraction. The addition of these antioxidants is performed during the soybean biodiesel washing process in an unconventional manner. The results obtained are statistically analyzed and compared to the control. The induction time (IT) for the biodiesel samples washed with ethanolic extract of pecan nutshell (5 g L−1), aqueous extract of pecan nutshell (12 g L−1) and methanol/water extract of pecan nutshell (12 g L−1), are, respectively, 9.46, 7.60, 7.43 h. The activation energy and the storage time of the biodiesel samples washed with the extracts are also studied. The order of reaction of the oxidation kinetics of biodiesel is first order.

Potential applications of pecan residual biomasses: a review

“…The addition of these antioxidants is carried out during the soybean biodiesel washing process in an unconventional manner. The concentrations of the extracts that provided the longest induction time for the biodiesel were the ethanol extract of the hull at a concentration of 5 g/L (9.45 h), aqueous extract of the shell at a concentration of 12 g/L (7.40 h) and methanol extract and shell water at a concentration of 12 g/L (7.37 h) [21].…”