Direct transesterification of black soldier fly larvae (Hermetia illucens) for biodiesel production

In this study, direct transesterification with a combination of methanol and a cosolvent was demonstrated to be promising for the production of biodiesel from black soldier fly larvae (BSFL) biomass. Of the solvents tested, n-hexane was identified as the most effective cosolvent for the reaction, resulting in a 14.5-fold increase in the biodiesel yield, compared with the reaction without a cosolvent. The direct transesterification using n-hexane as a cosolvent was then optimized to maximize the biodiesel yield. The highest biodiesel yield of 94.14% was achieved at an n-hexane:methanol volume ratio of 1:2 (v/v), a solvent dosage of 12 mL, a catalyst loading of 1.2 mL, a temperature of 120 degrees C, and a reaction time of 90 min. The properties of the BSFL biodiesel were also tested, and most-such as the biodiesel's density (875 kg/m(3)), water content (0.03 mg/kg), ester content (98.3%), acid value (<0.8 mg KOH/g), viscosity (5.2 mm(2)/s), flash point (121 degrees C), and cetane index (50)-met the specifications of the European standard EN 14214. This study suggested that direct transesterification using n-hexane as a cosolvent could be a promising method for biodiesel production from BSFL and decrease production costs. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.