Biorefining of Eruca sativa plant for efficient biofuel production†
Biomass biorefining can improve the economy of biofuel production through synthesizing multiple value-added products and minimizing waste production. In this study, Eruca sativa was evaluated as a biorefining feedstock. High free fatty acid oil was first pretreated through an esterification process and then applied to an alkaline transesterification reaction for biodiesel production. The effects of the operating conditions were studied to maximize the biodiesel production yield. Sodium hydroxide pretreatment was employed to improve biogas and ethanol production from the plant residues. The pretreatment at 100 °C for 60 min represented the most promising potential for ethanol production, resulting in over 215% improvement in the yield. The pretreatment at 0 °C was more successful than the pretreatment at 100 °C for the biogas production; however, the results were not universal. Even though in the case of the straw, the pretreatment for 60 min increased the methane production by 233% compared to untreated straw, it showed a negative effect on the anaerobic digestion of the seed cake. At the best conditions, 1 kg of Eruca sativa yielded 140 g biodiesel, 16.8 g glycerol, 76.2 g ethanol from the pretreated straw, and 60.0 L (39.3 g) methane from the untreated seed cake.