Recent developments, challenges, and environmental benefits of using Hermetia illucens for bioenergy production within a circular economy approach

This study proposes a novel integrated biorefinery approach that combines Hermetia illu-cens (Black Soldier Fly) larvae treatment, anaerobic digestion (AD), and hydrothermal car-bonization (HTC) to enhance the valorisation of fat-rich food residues. The process was designed to improve biogas yields while mitigating the inhibitory effects of lipid accumu-lation in AD systems. Results from larval bioconversion showed effective fat removal and a promising potential for protein and biomass valorisation. Downstream integration with AD and HTC enabled thermal self-sufficiency, enhanced energy recovery, and improved digestate dewaterability. Additionally, HTC process water recirculation to the AD unit was evaluated, considering its acidic nature and impact on biomethane production. A thermally integrated process flow was proposed, enabling efficient heat exchange and re-duced external energy input. The overall system allows for multi-product recov-ery—including biogas, hydrochar, and larval biomass—offering a sustainable pathway for circular bioeconomy applications. This study illustrates the feasibility of a synergetic process chain that maximises energy recovery and resource efficiency from food industry waste streams.