Technical and economic analysis of hatchery residue valorisation via fermentation and black soldier fly larvae bioconversion in Quebec

Abstract In response to the challenges associated with conventional management of hatchery residue in Quebec, the technical and economic feasibility of an alternative valorisation system coupling initial fermentation and subsequent black soldier fly larvae bioconversion was evaluated. This study aimed to propose a viable implementation strategy and determine the break-even sales prices of larvae and frass to ensure profitability. A total of 32 production scenarios were compared using an economic prediction tool accounting for geographical and system-specific factors. These scenarios included centralised and decentralised models at scales ranging from 10 to 110 tonnes of residues treated per week (tpw), as well as different reproduction strategies (in-house colony vs external neonate sourcing) and sales approaches (bulk vs retail). Capital and operational costs, along with potential revenues, were estimated for each scenario over 4 years, considering a production start at 30% of design capacity and subsequent ramp-up of 30% per year. Results indicate that a large-scale centralised model with an in-house black soldier fly colony and retail sales is the most profitable one. However, decentralised models could also benefit hatcheries processing at least 15 tpw of residues by reducing fees associated with conventional thermal rendering services. Beyond the economic aspects, challenges related to the supply of skilled labour, social acceptability, regulatory constraints, and market competition for the supply of residues and the marketing of insect products are discussed to ensure the feasibility of implementing the process in Quebec.