The NENUPHAR Deliverable 4.4 presents a comprehensive framework to design and implement innovative circular business models in the context of nutrient recovery from waste streams, with a focus on biobased fertilizers. The deliverable examines the shift from linear to circular systems in fertilizer production, highlighting the potential of waste streams such as pig slurry, dairy wastewater, and sewage sludge as valuable resources. It includes a market analysis of biobased fertilizers, assesses the environmental, economic and social impacts of the current linear fertilizer production, and identifies where value can be added in circular business models. Key strategies and actors for enabling the transition are outlined, together with the barriers that must be addressed, and the deliverable proposes relevant economic indicators for evaluating profitability and long-term viability. Findings are used to propose a sequential methodology to ease the transition to and development of circular business models. The findings underscore that both the supply and demand sides of the market must be considered for establishing long-term, sustainable and stable circular business models of biobased fertilizers from waste, particularly the role of farmers as end-users in emerging bioeconomy value chains, as consumer acceptance is key in new markets. The analysis also explores key risks, scaling challenges, and the types of policy and financing support needed for the transition. By identifying critical barriers and enabling factors, this deliverable lays the ground for regionally adapted, economically viable, and socially accepted circular business models that align with the European Green Deal and circular bioeconomy strategies. The conclusions point to a systemic and collaborative approach for the transition to work and be implemented in a fair way for all stakeholders, but specifically the local agents involved in the different value chains. By identifying enabling conditions and potential barriers, this deliverable contributes to the development of circular business models that can be economically viable but also locally adapted and socially inclusive. It emphasises that successful circular transitions rely as much on collaboration, regional engagement and acceptance as they do on technological solutions.
Carrera et al. (Thu,) studied this question.