A multidisciplinary team of researchers from Université Laval, INRS, UQTR and Nutrimago, led by Professor Grant Vandenberg, has developed a new multi-stage circular value chain for the valorization of biomethanization effluents. Read a summary of their work.
The development of new integrated approaches to waste management and energy recovery is an important strategy for meeting sustainability requirements and completing a sustainable circular bioeconomy. In fact, with the Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs’ program for the treatment of organic matter by biomethanization and composting, several biomethanization projects have been implemented or approved. Although this recovery method generates biogas that can be used as a source of energy, the biomethanization process generates digestate (solid and liquid), which remains costly to manage. Efforts are underway to valorize the solid fraction of digestate, so as to give it a higher economic value than composting or land application. However, the liquid fraction of digestate remains little valorized to date.
The aim of this project was to study the pre-feasibility of integrating a circular value chain involving the valorization of liquid digestate from biomethanization, microalgae production and insect rearing. Research activities include experiments on the cultivation of microalgae from liquid digestate from biomethanization and the rearing of black soldier flies using the harvested microalgae biomass as a supplementary food source. Extensive studies have been carried out to develop a culture medium composition based on liquid digestates. The results obtained are initially being used by the Nutrimago company to develop edible insect farming as a new source of sustainable protein for animal feed. The project also has the potential to contribute to the valorization of effluents from the future Coop Carbone biomethanization platform in Victoriaville. The integration concept developed as part of this project will be presented to the scientific, municipal and regional communities, to stimulate their interest in this model approach to the circular bioeconomy.