Low Carbon Bio-Based Building Materials from Organic Waste: A Closed-Loop Production Model Within Circular Neighbourhoods
摘要
Circular cities would allow a ten-fold CO2 reduction, cutting emissions related to building and energy production. In this perspective, the scale of the circular neighbourhood is relevant: an eco-district in terms of energy efficiency and use of renewable sources but structured with attention to all resource flows and oriented towards zero-waste. At the neighbourhood scale, the organic waste stream represents a significant share of the overall waste production. Residual biomasses, produced both within and near the eco-district, are a strategic supply basin for various purposes, with the dual advantage of reducing waste and gaining energy, biofuels, bio-materials, and bio-products. This contribution systematises the outcomes of three researches—all aiming to combine decarbonisation and circularity goals through a multi-scalar life cycle design approach—by identifying the most innovative applications for organic waste in a ‘zero km’ production of building materials and components. The first research, working on key enabling technologies for the built environment with a view to climate mitigation, opened to subsequent one, which specifically addressed the relationship between climate neutrality, green technologies, and circular communities and developed a framework of integrated strategies for circular neighbourhoods’ design, while the third looks at how organic waste can be turned into bio-materials through circular processes that can be implemented within neighbourhoods. Research activities adopted different methodologies, in distinct key steps: interconnected literature reviews; analysis of numerous international best practices at the neighbourhood scale; analysis of the main resource flows within neighbourhoods; study on the main types of biomass produced in and around the neighbourhoods, and of collection, transformation, and reuse technologies; selection, analysis, and collection in a database of case studies of bio-based building materials from organic waste; definition of a closed-loop production model for low carbon bio-based materials applicable at the neighbourhood scale in relation to the context.