Algae biopolymer towards sustainable circular economy

This thesis focuses on the theoretical and philosophical basis and robustness of existing methods of circular economy, life cycle assessment and other related methods focusing on issues of sustainability, food systems and diet. The purpose of this thesis is to identify weaknesses and strengths of current methods related to sustainability and food systems, and provide possible directions for improving current methods and practices.Current circular economy and LCA studies of the interrelationships among environmental sustainability, food systems and diet very often have limitations, including narrowly defined boundaries of the food systems, insufficient sustainability indicators, and limitation of databases and so on. These problems indicate that the current circular economy and LCA studies to some degree deviate from the initial need of more systemic or holistic approaches and views (Wikstrom et al. 2014; Frischknecht et al. 2016; Peters et al. 2010).To better understand those problems and to find solutions, this study conducted a systematic review on studies of LCA and circular economy on the topic of food system and diet sustainability, and conducted meta-analysis of relevant research methods and models focusing on the interrelationships among environmental sustainability, food systems and diet. By doing this, the study critically evaluated the use of circular economy principles and related concepts of a biophysically based economy, and contributed to methodological and theory developments in transdisciplinary integrated research for understanding the interrelationships. The thesis examined and interpreted a set of existing quantitative and conceptual methods related to circular economy focusing on the interrelationships among sustainability, food systems and human diet, in order to investigate: first, the theoretical and philosophical basis for links between economic and biophysical components in the common integrative tools and models used in sustainability decision-making of food systems; second, the robustness of present-day methods or models for analyses involving environmental impacts, resource demands, and economic measures. The thesis investigated what common sustainability models were based on, mainly in terms of epistemology, what they were intended for, and how they could possibly be combined or coupled methodologically in the future. This required using concepts and methods from systems thinking and analysis, scientific understanding of processes of social-ecological system change, and also the philosophy of science.This study found that there was a major emphasis on using GHG emissions and sometimes GHG emissions as the only indicator in LCAs to measure environmental sustainability, and little attention has been paid to look at the issue from the angles of health and food systems. The incomplete inclusion of food life cycle phases and selection of sustainability indicators for assessment in studies of LCAs and circular economy had their apparent advantages and limitations. To mitigate the limitations, this study suggested researchers find a balance between quantification and wholeness when using LCA to evaluate food system sustainability. For stronger food circular economy, this research recommended integrating the attributes of temporality, seasonality, regionality and complexity of food into the contexts of circular economy and circular bioeconomy. Also, focusing on management strategies to enable better circularity to optimise food systems rather than a single food product or waste, and on improving cross-chain valorisation of food wastes rather than valorisation of a single type of wastes also proved to be useful for that purpose. This study strongly suggested using systems thinking, stronger boundary critique, inclusion of broader phases and sustainability indicators, focusing more on the sustainability impacts of activities at the consumer end of the food life cycle, and further developing selection criteria for indicators to improve the current method of LCAs and circular economy.The outcomes of this thesis are expected to feed into future system analysis and modelling of interrelationships among environmental sustainability, food systems and human diet and health.

Corporate Sustainability Reporting provides essential data for academic and empirical research on sustainability and the still-growing adoption of the circular economy by companies. Despite the wide attention that the circular economy receives from the academy, a systematization and hierarchy of the strategies that embrace the sustainable circular economy are still necessary. In addition, there is a limitation of research on the analysis of Corporate Sustainability Reporting in emerging economies. In this study, fifty sustainable circular economy strategies emerged from a systematic literature review, arranged among nine categories. The differential of the identified strategies is the expansion of strategies for a sustainable circular economy vision. Then, 51 Corporate Sustainability Reporting from 17 multinational companies operating in Brazil in 2016, 2018 and 2020 were analyzed to identify companies’ adoption of these strategies. The Corporate Sustainability Reporting analysis results suggest that companies operating in Brazil are directing significant efforts toward a sustainable circular economy. Based on these two results and the theory of business process management, we proposed the Business Process for Sustainable Circular Economy framework.

Driving sustainable circular economy in electronics: A comprehensive review on environmental life cycle assessment of e-waste recycling

Transitioning to a circular economy is indispensable for the construction industry to achieve sustainable development goals. Understanding trends, gaps, and opportunities in life cycle assessment (LCA) for adopting a circular economy is critical. This study investigates the development of publications, identifies the most effective documents, authors, and countries, and highlights critical issues, knowledge axes, active research areas, and knowledge gaps. The study screened 196 out of 280 articles from the Scopus database and conducted a bibliometric analysis using CiteSpace and VOSviewer. Document clustering analysis identified the main research domains, and thematic classifications of knowledge areas and axes were provided. Additionally, development opportunities and knowledge gaps were identified through a full-text analysis of selected articles. The results show an increase in publications post-2017, with key research clusters including "Critical consideration," "Circular building component," "Building material," "Design for disassembly," "Integrated load match analysis," "Adaptive reuse project," "Data bank," "Prospective life cycle assessment," "Investment decision," and "Environmental comparison." Over 60% of the documents propose circular design solutions, end-of-life strategies, and alternative materials, while more than 80% focus solely on the environmental aspect. Only 4.6% develop integrated indicators, 2.5% automate LCA, 2.1% compile life cycle inventory databases, and 2% consider the social dimension. The findings emphasize the need to develop integrated indicators, methods, life cycle inventory databases, and automation tools based on integrated platforms and emerging technologies like building information modeling. This research identifies current knowledge gaps, suggests future research directions, and enhances understanding of how to make LCA more compatible with the circular economy.

Organic waste management is crucial for sustainable climate change adaptation and mitigation. It supports a circular economy by recycling and repurposing waste, considering the entire product life cycle. This includes initiatives to recycle and repurpose organic waste as valuable resources, promoting a circular economy approach. The aim of the current study is to determine the best strategy for managing organic waste that can support a sustainable circular economy. SWOT analysis is a strategic planning tool based on strengths, weaknesses, opportunities, and threats. The QSPM assesses the attractiveness of alternative strategies for managing organic waste, evaluating external and internal factors that influence the organization. Further research is needed to promote sustainable circular economy principles.This research used the SWOT and QSPM Model to determine the best strategy for managing organic waste that can support a sustainable circular economy. The process involves analyzing internal and external factors of an organization, using the SWOT matrix to identify alternative strategies for programs or activities, and then using QSPM analysis to determine the sequence of these strategies and determine the best to lowest-value strategy outcomes, ensuring data input and decision-making. This study has been carried out in Garut, West Java, Indonesia in 2023. The study analyzes the progress of organic waste processing in Garut Regency using the SWOT-QSPM approach. The results provide insights into the organic waste management strategy for a sustainable circular economy, highlighting the importance of recycling organic waste into new products and supporting society's economy. The circular economy principle can be applied to the processing of organic waste by using BSF, a biological agent that can produce livestock feed and plant fertilizer, reducing the amount of organic waste sent to landfills. The strategies discovered can guide community programs, empowering those without fixed incomes to manage waste. The cultivation of BSF can be integrated with the farm, aiming to reduce poverty and unemployment rates, convert unused land into a community-managed waste management center, aiming to enhance production and income, educate and support the well-being of the community. The best practices for handling organic waste in Garut Regency to promote a sustainable circular economy have been determined by the SWOT-QSPM model. The chosen strategy prioritized 3 main aspects out of 7 alternative strategies : (1) Recruiting society members to manage organic waste processing centers as a routine activity and additional income through processing and cultivation programs; (2) Increasing productivity and scaling up the processing of organic waste to obtain diverse products with higher economic value; (3) Providing direct training and education on organic waste processing to the society to demonstrate the economic value that processed organic waste can generate.

Toward a circular economy for plastics

A circular economy is considered one of the most pertinent solutions to contemporary socioeconomic and environmental sustainability challenges, such as climate change, biodiversity loss and resource depletion. The transition from a linear to a circular economy requires the support and participation of various organisations and institutions as well as stakeholders at all levels of society. This edited volume examines the role and importance of stakeholder engagement in a sustainable circular economy from multiple theoretical and practical perspectives. We understand a sustainable circular economy as a pathway to a more environmentally friendly and socially inclusive society and stakeholder engagement as an important tool to catalyse this journey. This volume provides an in-depth, research-based overview of how stakeholder engagement can catalyse the transition towards a sustainable circular economy and foster and support sustainable change. It provides an up-to-date discussion of theoretical and practical advances that is intended for researchers, policymakers and practitioners working on the circular economy.

PurposeThe interpretation is a fundamental phase of life cycle assessment (LCA). It ensures the robustness and the reliability of the overall study. Moving towards more circular economy requires that different waste management options are systematically scrutinized to assess the environmental impacts and benefits associated to them. The present work aims at illustrating how a sensitivity analysis could be applied to the impact assessment step supporting the interpretation of a LCA study applied to a waste management system that includes material recovering. The focus is on toxicity-related and resource-related potential impacts as they are considered among the most critical ones, which may affect the way the final benefit from material recovery is evaluated.MethodsPossible alternatives in terms of impact assessment assumptions and modelling are tested by performing a sensitivity analysis on a case study on electric and electronic waste. For the toxicity-related impact categories, first, a sensitivity analysis is performed using different sets of characterization factors for metals aiming at identifying how they are affecting the final results. Then, an analysis of the relative contribution of long-term emissions in upstream processes is carried out aiming at unveiling critical issues associated to their inclusion or exclusion. For the resource depletion impact category, a sensitivity analysis has been performed, adopting different sets of characterization factors based on existing models for minerals and metals as well as recently proposed sets accounting for critical raw materials.Results and discussionThe indicator of the ecotoxicity impact category obtained by applying the updated characterization factors is about three times higher than the corresponding obtained by the USEtox model. The long-term emission result is responsible for the major part of all the toxicity impact indicators. Moreover, for the ecotoxicity indicator, excluding the long-term emissions changes the total results from being negative into positive. The sensitivity analysis for the resource depletion impact category shows that all the models applied result in a total avoided impact. A quantitative comparison among all the results is not possible as the different models use different units of measure.ConclusionsThe application of LCA is crucial for assessing avoided impacts and uncovers potential impacts due to recycling. However, contrasting results may stem from the application of different assumptions and models for characterization. A robust interpretation of the results should be based on systematic assessment of the differences highlighted by the sensitivity, as guidance for delving into further analysis of the drivers of impacts and/or to steer ecoinnovation to reduce those impacts.

In the context of speed up economic development, numerous environmental and social issues have emerged. Existing research primarily concentrates on circular economy (CE) and sustainability to solve these problems, but the relationship between CE and sustainability is tenuous. Sustainable circular economy (SCE) was proposed to strengthen the relationship between CE and sustainability. However, research on SCE remains dispersed and insufficient. To comprehensively explore SCE at company level, this research proposes a conceptual framework how corporate governance affect SCE based on resource-based view. In this framework, corporate governance factors (gender and generational diversity of the board, foreign ownership, institutional ownership, CEO with business educational background, and CEO tenure) can positively affect SCE through the mediation role of eco-innovation, and customers’ pressure can positively moderate the relationship between corporate governance and eco-innovation. This article fulfils the lack of research on SCE, and it provides company managers with decision-making guidance to improve corporate governance structure to enhance SCE performance.

The UN 2030 agenda of Sustainable Development Goals (SDGs) envisions a future of inclusive equity, justice and prosperity within planetary boundaries, and places an important emphasis on ending poverty (SDG 1) and on sustainable economic growth (SDG 8). Target 8.4 refers to the need to improve global resource efficiency in consumption and production, and decoupling economic growth from environmental degradation, the ultimate goal of a sustainable circular economy. Here, we explore the potential of the transition to such an economy, and discuss the transformation required for moving away from our current model of consumption with its ever increasing generation of waste. The primary aim of such transformation is to rethink what we understand as growth, in order to redefine what is meant by progress and, in the process, redesign our economies, ultimately decoupling our prosperity from material consumption, carbon emissions and waste. Dematerialisation, servitisation, collaborative consumption and a shift from ownership to access have the potential to restructure the economics of consumption, accelerate decoupling, and help us to envision and potentially create a circular economy that delivers social, economic and environmental benefits for all. However, their current deployment without policy steer, public support and appropriate technology developments could turn to be a missed opportunity for ensuring sustainable economic growth fully aligned with sound environmental stewardship and social development, and the transition to a truly sustainable circular economy.

The circular economy (CE) has become a key sustainability discourse in the last decade. The Netherlands seeks to become fully circular by 2050 and the EU has set ambitious circularity targets in its CE Action Plan of 2015. The plastics sector, in particular, has gained a lot of attention as it is a priority area of both the EU and Dutch CE policies. However, there has been little research on the different and often contested discourses, governance processes and policy mechanisms guiding the transition to a circular economy and society. This paper aims to fill these gaps by asking what circular discourses and policies are being promoted in the Netherlands and what sustainability implications and recommendations can be drawn from it. It does so through a mix of media analysis, policy analysis, semi-structured interviews, and surveys using Q-methodology. Results indicate a dominance of technocentric imaginaries, and a general lack of discussion on holistic, and transformative visions, which integrate the full social, political, and ecological implication of a circular future. To address those challenges, this research brings key policy insights and recommendations which can help both academics and practitioners better understand and implement the transition towards a sustainable circular plastics economy.

The creation of a more sustainable economy is one of the main targets of the European Green Deal and the new Circular Economy Action Plan. Technological innovation is needed, among other things, to render materials, products, and production processes more sustainable. Given the goals of the European Green Deal, the regulatory concept of “Safe and Sustainable by Design” is increasingly receiving attention. The concept is (arguably) a precautionary and preventative measure that is implemented at the early stages of the design of a technology. Therefore, it is often described as a tool for lowering the risks that follow from efforts to create a more circular economy. The concept was included in the European Chemicals Strategy of the European Commission. The aim of the strategy is to accelerate progress towards the discovery of more sustainable chemicals and towards a toxicity-free environment. In this paper, we will explore the benefits and disadvantages of integrating the “Safe and Sustainable by Design” concept into the regulation of technology. As a form of regulation by technology, this concept can enhance sustainability. We will first describe the origins of the concept and its current use. Then, we will analyse its implications for the circular economy.

Circular economy and renewable energy infrastructure such as offshore wind farms are often assumed to be developed in synergy as part of sustainable transitions. Offshore wind is among the preferred technologies for low-carbon energy. Deployment is forecast to accelerate over ten times faster than onshore wind between 2021 and 2025, while the first generation of offshore wind turbines is about to be decommissioned. However, the growing scale of offshore wind brings new sustainability challenges. Many of the challenges are circular economy-related, such as increasing resource exploitation and competition and underdeveloped end-of-use solutions for decommissioned components and materials. However, circular economy is not yet commonly and systematically applied to offshore wind. Circular economy is a whole system approach aiming to make better use of products, components and materials throughout their consecutive lifecycles. The purpose of this study is to enable the integration of a sustainable circular economy into the design, development, operation and end-of-use management of offshore wind infrastructure. This will require a holistic overview of potential circular economy strategies that apply to offshore wind, because focus on no, or a subset of, circular solutions would open the sector to the risk of unintended consequences, such as replacing carbon impacts with water pollution, and short-term private cost savings with long-term bills for taxpayers. This study starts with a systematic review of circular economy and wind literature as a basis for the coproduction of a framework to embed a sustainable circular economy throughout the lifecycle of offshore wind energy infrastructure, resulting in eighteen strategies: design for circular economy, data and information, recertification, dematerialisation, waste prevention, modularisation, maintenance and repair, reuse and repurpose, refurbish and remanufacturing, lifetime extension, repowering, decommissioning, site recovery, disassembly, recycling, energy recovery, landfill and re-mining. An initial baseline review for each strategy is included. The application and transferability of the framework to other energy sectors, such as oil and gas and onshore wind, are discussed. This article concludes with an agenda for research and innovation and actions to take by industry and government.

According to sustainability transitions theory, socio-technical change requires a convergence of politics, social change, technology, and niche innovations. Recently, a circular economy has been proposed as the engine of such change in the EU New Green Deal and Germany. Mainstream circular economy emphasizes the closing of material loops as the way to ensure green growth, and there is a key role for design to achieve such change. According to reports, however, the global appetite for a circular economy remains limited and critics have pointed to several contradictions between the rhetoric and reality of the circular economy and sustainable development. In addition, current formulations of circular economy misrepresent the plurality of discourses for a sustainable circular economy and the role of expert and diffuse circular design. In this study, we employ the recently articulated ten principles for a sustainable circular economy and society to analyze two contrasting circular roadmap projects in Germany, which reflect two contrasting technical and reformist circular discourses, and understandings of the role of design. We find that there are narrow and broad interpretations of design inherent in these circular policies as well as the exemplification of the difference between a technical circular economy and reformist circular society discourses. The practical applied value of this analysis is that the framework can be employed to analyze other policies.

With the increasing global demand for plastic, research efforts have been focused on renewable alternatives to fossil-derived plastics and sustainable end-of-life options. Biomass from terrestrial or aquatic plants is used as the renewable raw material for polymers production, which are often referred to as ‘bio-based’. Bio-based plastic life cycles largely consist of four phases: terrestrial or aquatic plant cultivation; polymer (e.g. polysaccharides) extraction; bio-based plastic production; and end-of-life. As a systematic and rigorous evaluation framework, Life cycle sustainability assessment (LCSA) provides an integrative and holistic perspective for multi-criteria decisions on a given product or system. LCSA consists of three pillars, environmental life cycle assessment (LCA), life cycle costing and social-LCA. This chapter focuses on the environmental aspects and presents two LCA case studies to discuss different types of biodegradable biopolymers, including starch-based bio-composite and biosynthesized polymer. The focus of LCA case studies is to highlight environmentally damaging steps and compare the bioplastic with petrochemical counterparts. Regardless of processing technologies, both starch-based bioplastic case studies suggest environmentally damaging steps focusing on feedstock resources, applications and end-of-life. Despite the environmental advantages of bioplastic at the refinery gate, starch-based bio-packaging in general cannot compete with petrochemicals with closed-loop recycling at end-of-life. This chapter also provides an overview of sustainable polymers sourced from renewable resources and discusses a range of carbon sinks and emitters, energy sinks and sources emerging from bioplastic life cycles. Our research highlights the life cycle insights derived LCA and systems engineering approach. By process integration and optimization in particular by minimizing energy sinks and carbon emitters, sustainable polymers produced from renewable resources have great potentials to contribute to a sustainable circular economy (CE).