Fish and meat production and processing will grow drastically in the coming decades. In aquacultural systems, insects are gaining interest as feed to provide a sustainable alternative to the fishmeal paradox, whose production leads to high consumption of resources and negative environmental impacts. Within the scope of this study, the production of fish feed from Hermetia illucens larvae and Lemna minor in an inline recirculating aquaponics model for urban sites was developed and optimized, which efficiently combines waste and environmental service concepts in one production system. At the same time, the value chain produces high-quality, market-accessible raw materials for the fish feed industry. All investigations were accompanied by a comparative Life Cycle Assessment (LCA) to measure and compare ecological effects to finally result in sustainable alternatives. The results achieved in this research show that fish feed based on Hermetia illucens and Lemna minor can have the potential to be ecologically competitive or more sustainable than standard feed. It should be noted that the comparison here represents the results of the project on a pilot scale. Various optimization potentials were shown, which are essential for the large-scale implementation of the breeding of both species as well as their processing up to the fish feed pellets.

Biomass waste and waste-derived feedstocks are important resources for the development of sustainable value-added products. However, the provision and preparation of biomass as well as all possible downstream processing steps need to be thoroughly analyzed to gain environmentally sound and economically viable products. Additionally, its impacts are substantially determined by decisions made at early development stages. Therefore, sustainability assessment methods can support to improve the production process, reduce waste, and costs and help decision-making, at the industrial as well as policy levels. Life Cycle Assessment (LCA) is an analysis technique to assess environmental impacts associated with all product's life cycle stages. It is a well-established tool to drive development towards a sustainable direction, however, its application in the earlier research phase is surrounded by practical challenges. The overall objective of this paper is to provide an understanding of the environmental issues involved in the early stages of product and process development and the opportunities for life cycle assessment techniques to address these issues. Thus, herein two LCA case studies are presented, dealing with novel approaches for food and feed supply through implementing the valorization and upcycling of waste and side-streams, respectively. In both case studies, LCA is used as a decision support tool for R&D activities to launch environmentally sound products to market, as well as to highlight the usefulness of LCA for identifying environmental issues at an earlier stage of development, regardless of product, process, or service.

In response to the construction sector’s contribution to the climate crisis and exacerbation of social inequalities, we explore sustainable alternatives in building construction, informed by the illustrative case study of the Polycare construction system. First, through a Life-Cycle Assessment (LCA) method, we show that the ecological footprint of circularity-oriented buildings based on polymer concrete is significantly lower than that of conventional cement concrete buildings. Despite the drawbacks of polymer concrete, its high-performance properties and the possibility to integrate secondary materials in its recipe can result in a reduced carbon footprint. When coupled with design-embedded modularity that facilitates circular processes (e.g., the disassembly and reuse of building components), buildings similar to those in the case study demonstrate potential for transitioning towards comprehensive sustainable building practices. Further, we discuss how this sustainability potential could be enhanced, drawing from interviews with Polycare’s stakeholders and key literature findings. In this direction, we provide a set of proposals anchored in the argument that threefold “circularity, localisation, and openness” is vital for sustainable and affordable alternatives, with openness being a crucial element for fostering innovation, adaptability, and scalability in building processes.

This study evaluates the economic and environmental sustainability of protein-rich crops (quinoa, faba beans, chickpeas, and lentils) cultivated in Europe. Using life cycle assessment (LCA) and life cycle cost (LCC) analyses, it examines the impacts of these crops grown in the Netherlands, Spain, and Italy under both organic and conventional farming methods. Unlike previous agri-food studies that mostly assess sustainability dimensions in isolation, this research integrates LCA and LCC to provide a comprehensive eco-efficiency evaluation, offering novel insights into the trade-offs between environmental impact and economic viability. In addition, this study focuses on the cultivation of four protein-rich crops that are novel to Europe. The results reveal significant variability in environmental impacts, including climate change impact and land use, as well as profitability, across different crops, countries, and farming practices. Dutch conventionally grown faba beans demonstrate the highest eco-efficiency, while organic lentils in Italy and organic quinoa in the Netherlands also perform well. The study highlights the instability of crop yields and suggests that local production of these protein-rich crops could reduce Europe's dependency on imported soy, although careful consideration of regional suitability and farming methods is necessary. The findings aim to guide farmers and policymakers in promoting sustainable protein-rich crop production in Europe.