Synergistic integration of entomological and thermochemical approaches for the sustainable energy production from organic waste

Abstract

The technical limitations of single waste valorisation platforms are evident. To address these, this study combined entomological and thermochemical approaches for organic waste management to sustainably improve the overall process efficiency. Black soldier fly larvae (BSFL) consumed large amounts of organic waste (78.7 wt%) and produced lipids. These lipids were extracted from the BSFL biomass and converted into biodiesel. Noncatalytic transesterification showed a higher biodiesel yield (92.1 wt%) than acid-catalysed transesterification (86.6 wt%)-the conventional biodiesel production methodology. Pyrolysis was conducted to further valorise residual organic waste after BSFL rearing. Catalytic pyrolysis under N2 conditions produced 108.9 mmol of syngas (H2 and CO). To introduce sustainability into the process, CO2 was used as a gas medium instead of N2, which enhanced syngas production (121.9 mmol) while consuming 52.2 g of CO2. The CO2 consumed during CO2-assisted pyrolysis offset 28 wt% of the CO2 emitted from BSFL rearing, resulting in a 0.7-fold reduction in overall CO2 emissions for the entire process compared to N2 pyrolysis-integrated platform. This integrated platform-BSFL rearing and CO2-assisted pyrolysis-effectively increased energy output through biodiesel and syngas production while reducing CO2 emissions, contributing to a more sustainable and efficient approach to managing organic waste.