Waste reintroduced in the kitchen: life cycles inventories of representative waste-to-nutrition pathways

Abstract

Transforming residual streams into novel ingredients such as insects, microorganisms, or protein extracts, is increasingly promoted to mitigate global environmental impacts. Yet, to unambiguously quantify the potential environmental benefits and implications of scaling these conversion pathways, a comparative assessment framework is missing. To this end, we propose a common life cycle inventory (LCI) modeling strategy to forecast the performances of 16 representative “waste-to-nutrition” pathways according to 18 input streams characteristics and 293 technological parameters. Analyzed over eleven contrasted case studies, proposed LCI models not only allow to compute the untapped potential of waste-to-nutrition pathways, but also unravel trade-offs between production yields, energy requirements, and input streams composition. We show that scaling novel waste-based proteins production pathways could totally offset French protein feed imports, provided substantial adaptation of energy systems and mobilization of biomass resources. Based on in-depth literature review and data collection, proposed LCI modelling approach is expandable to the broader set of waste recovery technologies, and can support the design of sustainable circular bioeconomy strategies.