Circular Products Research Articles

New Management Strategy Framework for Effectively Managing Microplastic in Circular System Form Plastic Product Manufacturing to Waste Treatment Facility

In recent years, concerns regarding the environmental impact of microplastics (MPs) have led to increased international attention on these pollutants. Although the initial focus was largely directed toward marine environments, land-based pollution sources, including MP release, have been recognized to directly affect marine ecosystems. Therefore, soil-, atmosphere-, groundwater-, and river-based research is ongoing. However, when considering sources of MP, it is necessary to examine the circular system of plastic in terms of raw materials, production, consumption, discharge, and disposal (recycling). Accordingly, the present study proposes a strategy to effectively manage MPs using this circular system. First, the factors influencing MPs in the circular system were identified, and MPs at the system’s final stage, i.e., at the waste treatment facility, were subsequently investigated. Using the concept of MP waste (MPW), strategies were then developed for effective MP management within the circular system. Applying the proposed theoretical strategy to the Korean waste management system revealed that the new policy framework improves the current MP management system. Overall, this study provides fundamental data for establishing new or improved MP management schemes from a waste sector perspective.

Circular product development strategies for sustainable production and consumption based on waste valorization

PurposeThis study aims to propose guidelines for developing circular products based on waste recovery that are aligned with sustainable production and consumption.Design/methodology/approachA systematic literature review and case studies on circular product development were conducted. In total, 15 companies with products based on waste recovery and aligned with sustainable production and consumption goal were studied.FindingsThe results show the decisions and strategies applied at each stage of the new product development process, including the design for recycling, the use of waste as a raw material for products and the concern for reducing pollution and recovering end-of-life products.Practical implicationsThe cases studied meet the goals of efficient use of natural resources and waste reduction by preventing, reducing, recycling and reusing waste. For practitioners, a set of guidelines is proposed to help companies develop circular products based on waste recovery.Originality/valuePrevious studies have not evaluated the new product development process and circularity from the institutional theory and waste valorization perspectives.

Producing food from CO2 using microorganisms: Lots to do, little to lose!

BackgroundFor the first time, the recently held United Nations Climate Change Conference (COP 28) involved a summit leaders’ declaration to include global food production in their action plan to fight climate change. Reducing meat consumption is the primary way to take this fight seriously, nevertheless the global supply of people with high-quality protein is one of the central challenges of the coming decades. Producing microbial protein from CO2 (aka single cell protein, SCP) offers the unique opportunity to recycle both, CO2 from the atmosphere and food side streams, into consumer-oriented foods - an innovative path to a zero-carbon footprint diet. Scope and approachThe importance of utilizing CO2 as a substrate for microbial food production is underscored by comparative environmental footprint studies of various protein sources. This commentary systematically discusses the opportunities and technical challenges in realizing this vision. Key findings and conclusionsThe herein proposed acetate-based CO2-to-food framework carries the potential to decrease the environmental footprint of food production by several orders of magnitude in terms of greenhouse gas emission, water, and land usage. While all relevant process steps are already advanced to a high technological readiness level, the key engineering challenges encompass their consolidation to a circular process, scale-up and product formulation.

The Role of Consumers in Fostering Circular Economy in Indonesia

Consumers play an important role in transforming the economic system into a circular economy. Some literature highlighted that consumer demand has become an enabler for businesses to adopt circular practices. However, other literature argues that although consumers are aware of environmental sustainability issues, their adoption of circular products and services is still low, which is termed as an "intention–action gap." This "intention–action gap" becomes a socio-cultural barrier for businesses to adopt circular practices. This paper aims to increase knowledge and understanding about the role of consumers perceived by circular start-ups. A qualitative case study approach was employed by conducting in-depth interviews with four circular start-ups. This study is expected to shed light on the role of consumers either as enablers or barriers to the circular economy in Indonesia.

How to Advance Sustainable Innovations for Circular Bioeconomy: Perspectives from a Public Research Institute

This article presents a case study of public research institute innovation process for the circular bioeconomy in Finland. If an invention is to become an innovation, it requires actor alignment and cooperation from research to product development all the way to the end user. Despite the high uncertainty, the decision makers along the value chain need to identify possible directions and promising options, in addition to managing various risks. Support for these decisions is crucial to enable sustainable innovations. Furthermore, the role of public research institutions in providing “seeds” for innovations has been researched less extensively than the role of private companies or universities. This paper develops and tests a new circular bioeconomy product questionnaire to assist researchers. The questionnaire was designed for Natural Resources Institute Finland, combining risk management, new product development, and innovation process perspectives. The authors interviewed researchers and developed the framework further based on the interview analysis and tested it in a workshop. For the end product to succeed, it is necessary to understand the requirements of the entire value chain, especially the needs of end users. The research (and innovation) process should already involve stakeholders in the early stages to better meet their expectations.

Requirements for Design Methods from Circular Design to Support the Product Development of Products for the Circular Economy in SMEs

Against the backdrop of increasing ecological challenges, in connection with excessive use of resources, a rethinking of the current mode of operation of the economy and consumers is required. The circular economy, which describes a system in which products, components, and materials are preserved in recurring cycles, is seen as a counter-design to the currently dominant form of economy. The development of circular products plays a central role in the development of both consumer and capital goods. Design methods from circular design—a part of circular economy—form the basis for the development of circular products. Therefore, this contribution identifies and investigates evaluation criteria for the optimal selection of these design methods for use in small and medium-sized enterprises (SMEs). It is shown that design methods shall promote circular development of a product and focus on a systemic consideration of the product context along the entire product life cycle as well as closing technical and biological cycles. The contribution formulates evaluation criteria that address the assessment of the applicability, integrability in SMEs, and circularity of a design method and thus provide a basis for the evaluation of design methods from circular design. Product developers in SMEs are thus provided with a set of criteria to support them in product development for the circular economy.

Re-examining consumer engagement in the circular economy

PurposeThis study aims to deepen knowledge of consumers’ attitudes towards circular economy products by focusing on the enabling factors that influence their behaviours. The success of the closed-loop economy depends not only on innovation but also on the active participation of the consumer. In these models, the authors witness the transition from the centrality of production to the centrality of use. This paper investigates Italian consumers’ tendency to purchase second-hand products in the clothing sector, one of the most polluting industrial sectors, focusing on the enabling factors that influence their behaviours, the reasons for their purchases and the existence of differences between market segments.Design/methodology/approachTo accomplish this aim, a two-step investigation was carried out: a literature review and a quantitative analysis through a snowball survey involving 963 individuals, noting that non-random sampling restricts the validity of the findings within the considered sub-set of the Italian population. Statistical analyses were performed using the R 4.1.2 software environment along with Rstudio IDE v.1.4.1106 and the packages FactoMineR for cluster analysis and vcd for mosaic plots.FindingsEnvironmental knowledge/awareness and solidarity values have a significant positive effect on consumers’ attitudes and purchasing behaviour towards circular products within the selected sample. A strong statistically significant association (p-value ≪ 0.01) is confirmed between those who consciously purchase sustainable clothing and those who are members/supporters of environmental associations, know sustainable brands and the advantages of the circular economy. Significant relations also emerged in reference to gender and age. In detail, the purchasing of sustainable clothing was found to be positively associated with females and generation Y respondents. Theoretical, institutional and managerial implications stem from the experimental findings of this study.Originality/valueThis study investigates the point of view of demand. From this perspective, this paper proposes a consumer engagement paradigm that highlights the motivations and enabling factors prompting participation in circular economy processes and affecting purchasing practices and attitudes towards second-hand clothing products with regard to Italian consumers.

Exploring public attention in the circular economy through topic modelling with twin hyperparameter optimisation

To advance the circular economy (CE), it is crucial to gain insights into the evolution of public attention, cognitive pathways of the masses concerning circular products, and to identify primary concerns. To achieve this, we collected data from diverse platforms, including Twitter, Reddit, and The Guardian, and utilised three topic models to analyse the data. Given the performance of topic modelling may vary depending on hyperparameter settings, this research proposed a novel framework that integrates twin (single and multi-objective) hyperparameter optimisation for the CE. We conducted systematic experiments to ensure that topic models are set with appropriate hyperparameters under different constraints, providing valuable insights into the correlations between CE and public attention. In summary, our optimised model reveals that public remains concerned about the economic impacts of sustainability and circular practices, particularly regarding recyclable materials and environmentally sustainable technologies. The analysis shows that the CE has attracted significant attention on The Guardian, especially in topics related to sustainable development and environmental protection technologies, while discussions are comparatively less active on Twitter. These insights highlight the need for policymakers to implement targeted education programs, create incentives for businesses to adopt CE principles, and enforce more stringent waste management policies alongside improved recycling processes.

Green Tea and Green Coffee Therapy for Aortic Calcification Prevention in Metabolic Syndrome Model Rats: Effects on Expression of AKT, mTOR, RUNX2, and Osteopontin Levels

Metabolic syndrome (METS) consists of several independent risk factors for cardiovascular disease (CVD), one of which is vascular calcification (VC). Increased oxidative stress is essential in the pathogenesis of CVD in METS. One of the pathways involved in the pathogenesis of VC is the AKT pathway. Green tea and green coffee have many health benefits, including treating METS risk factors. Although several benefits of green tea and green coffee are known, there is not much information regarding the effects of these 2 extracts for treating heart disease, which is often found in METS sufferers. This research explores the benefits of green tea and green coffee extracts in preventing VC in METS through the AKT/MTOR mechanism. This research focuses on the mechanism of CVD in the AKT-mTOR, RUNX activity, and osteopontin (OPN) expression as one of the downstream pathogenesis of CVD in METS. The research was conducted on METS model rat treated with metformin and green tea with green coffee extracts. Male Sprague-Dawley rats were given a diet high in fat and sugar until they met METS for 4 months, then given treatment for 9 weeks. After 9 weeks, the rat had their aortas isolated for staining with specific antibodies to AKT1, MTOR, RUNX2, and serum OPN levels were measured using ELISA-sandwich methods. There was an increase in the expression of AKT1 and MTOR and a decrease in RUNX2 and OPN2, which was better than rat not treated with green tea and green coffee (p < 0.05). A significant reduction was found in the green tea and green coffee therapy group, which was better than when given metformin alone (p < 0.05). The results of this research showed that there is good potential for therapy using green tea and green coffee extracts to prevent VC in metabolic syndrome models. HIGHLIGHTS Metabolic syndrome consists of several independent risk factors for cardiovascular disease, one of which is vascular calcification. Increased oxidative stress is essential in the pathogenesis of cardiovascular disease in metabolic syndrome. This study explores the benefits of green tea and green coffee extracts in preventing vascular calcification in the metabolic syndrome model through the AKT/MTOR mechanism. This research focuses on the mechanism of CVD in the AKT-mTOR, RUNX activity, and osteopontin (OPN) expression as one of the downstream patogenesis of CVD in METS. The research was conducted on METS model rats treated with metformin and green tea with green coffee extracts. In conclusion, this study showed the potential for therapeutic use of green tea and green coffee extracts to prevent vascular calcification in rat models of metabolic syndrome by increasing AKT1 expression, decreasing MTOR and RUNX2, with the main implication of reducing the circular protein product, osteopontin. GRAPHICAL ABSTRACT

‘Let’s brew a new Brussels’: imaginaries of the circular economy

Abstract In this paper, I mobilise the notion of imaginaries to analyse a case of the circular economy (CE) in the region of Brussels, Belgium, where bread surplus from mass retail is upcycled to produce a local and more sustainable beer. I examine circular imaginaries and how they are translated into urban practices and materialised in the city. My analysis shows that the craft and post-industrial narratives of new circular products may find a positive echo at the urban level when re-development strategies to attract new productive activities mobilise similar narratives of creativity, innovation and craft skills. It concludes that CE risks becoming a rallying signifier helping to support a discourse coalition on the productive and circular city.

Circular Circular Economy Strategies for Small Domestic Appliance Design in China

China is the global largest home appliance manufacturer, and the increased manufacturing of small domestic appliance (SDA) products is leading to high carbon emissions in the world. Therefore, there is a need to upcycling SDA due to this phenomenon in China. The purpose of this study is to identify the best circular economy (CE) strategies for SDA to reduce SDA carbon footprint. Unfortunately, circular product design (CPD), CE approaches, methodologies, and tools in SDA were not widely developed. In this desktop study, it synthesizes the current SDA design characteristics, current SDA usage features, and recommending the CPD-SDA framework for China product design. The results found that when designers incorporate CPD framework in the early stages of SDA’s design, it could enhance product integrity hence lower carbon emission. The research will benefit manufacturers by enabling improved SDA circularity, as well as supporting the reduction of e-waste and carbon emissions in China and worldwide.

Towards Sustainable Consumption: Quantitative Insights into Consumer Behaviour on Circular Food Products

Abstract The concept of Circular Food Products, focusing on sustainability and waste minimization throughout the production and consumption cycle, has garnered significant attention recently. This research aims to provide empirical insights into factors influencing consumer behaviour regarding sustainability in the food industry. Using quantitative analysis techniques such as the questionnaire to measure attitudes, preferences and behaviours among consumers, and employing structural modeling for the collected data, the study yields important findings that advance knowledge in sustainable food consumption. These findings promote environmentally friendly and socially responsible practices within the food industry and among consumers. One key finding is the low level of consumer awareness about circular food products and their benefits. Perceptions varied, with some viewing these products as innovative and eco-friendly, while others considered them inferior to conventional products. This suggests the need for effective marketing campaigns to shape consumer awareness and perception of circular food products. Additionally, the research highlighted varying levels of awareness regarding the environmental impact of food production and consumption, with some consumers demonstrating strong concern for sustainability.These insights underscore the importance of targeted marketing and education to enhance consumer understanding and acceptance of circular food products, ultimately supporting the shift towards more sustainable consumption patterns.

Enhancing Circular Economy Practices in the Furniture Industry through Circular Design Strategies

The furniture industry represents a substantial segment of Europe’s economy, with the European Union producing approximately 25% of the world’s furniture. This sector is currently transitioning towards a circular economy. This study aims to thoroughly examine the circular initiatives undertaken by European furniture companies, emphasising the role of design in fostering innovative solutions. By employing a multiple case study methodology, the research demonstrates that existing circular solutions predominantly focus on materials and products, with significant adoption of circular design strategies. The majority of furniture companies are implementing these strategies to enhance resource efficiency and prolong product lifespans. Additionally, some companies are developing complementary service systems to improve product performance and longevity further. However, only a few have successfully implemented circular business models alongside circular product design strategies. This study also highlights that increasing user engagement and adopting a systemic perspective that includes various stakeholders in creating mutually beneficial solutions are areas that are still underdeveloped. Finally, we propose a framework to effectively guide furniture companies in implementing design strategies from a systemic perspective, aiming to generate comprehensive circular solutions within the European furniture sector.

Leveraging digital data to facilitate circular control in the aftermarket – experiences from an international manufacturing firm

PurposeGrowing research attention has been given to both the circular economy and digitalisation in accounting research in recent years, but there are few studies exploring how digital tools are used to develop, analyse and respond to information for circular decision-making in industrial organisations. Therefore, this paper addresses how the data from digital technologies are leveraged in the aftermarket of an industrial firm for circular control.Design/methodology/approachThe paper develops an analytical framework that is then used to frame the findings through a single case study of an international heavy equipment manufacturer for circular control.FindingsThe case provides examples of how digital technologies are used for circular control, framed within the analytical model as the key contribution. The study illustrates the different ways through which the accounting information from such technologies supports the service marketing function through circular control and the types of controls needed for this.Practical implicationsManagers in large industrial organisations should ensure customer-facing staff have adequate digital competences and knowledge of circular products and services for marketing, product design improvements and material recovery that can help decrease costs and improve customer satisfaction. The digital systems need to be integrated with upstream and downstream partners.Social implicationsUnderstanding the transition towards increasingly circular product-service systems in industrial firms is important for current and future generations.Originality/valueThe originality lies in providing an empirical example of how digital technologies can be used to facilitate circular control and support the service marketing function in the aftermarket of an industrial firm.

Triple Symmetric Sums of Circular Binomial Products

By employing the generating function approach, 16 triple sums for circular binomial products of binomial coefficients are examined. Recurrence relations and generating functions are explicitly determined. These symmetric sums may find potential applications in the analysis of algorithms, symbolic calculus, and computations in theoretical physics.

Are university students really hungry for sustainability? A choice experiment on new food products from circular economy

Consumers are demonstrating increasing awareness towards initiatives promoting sustainable practices in the food sector. This is particularly pronounced among university students, a segment known for its receptivity to sustainability initiatives. Utilizing a choice experiment, this study examines the Italian students’ preferences for fruit juice produced by a hypothetical company. Specifically, the research explicitly assesses the premium price attributable to a circular economy certification—a relatively new standard—in comparison with the widely recognized and appreciated organic certification. Furthermore, the study evaluates the potential additive value of possessing both certifications jointly. Results indicate that consumers are willing to pay a premium for products labelled with circular economy attributes. However, in the presence of an organic certification, the additive value of the circular economy certification is diminished by more than half. Finally, consumers who have received environmental training demonstrate a higher premium for such products, highlighting the role of education in promoting sustainable choices. These findings suggest that a potential market exists for circular economy-certified products, providing an incentive for businesses to adopt circular economy practices. Environmental training plays a relevant role in fostering sustainable transitions, thereby underscoring the significance of education in shaping conscious consumer behaviour.

Investigating demoulding characteristics of material jetted rapid mould inserts for micro­injection moulding using in­line monitoring and surface metrology

PurposeThis study aims to investigate the demoulding characteristics of material-jetted rapid mould inserts having different surface textures for micro-injection moulding using in-line measurements and surface metrology.Design/methodology/approachMaterial-jetted inserts with the negative cavity of a circular test product were fabricated using different surface finishes and printing configurations, including glossy, matte and vertical settings. In-line measurements included the recording of demoulding forces at 10 kHz, which was necessary to capture the highly-dynamic characteristics. A robust data processing algorithm was used to extract reliable demoulding energies per moulding run. Thermal imaging captured surface temperatures on the inserts after demoulding. Off-line measurements, including focus variation microscopy and scanning electron microscopy, compared surface textures after a total of 60 moulding runs.FindingsA framework for capturing demoulding energies from material-jetted rapid tools was demonstrated and compared to the literature. Glossy surfaces resulted in significantly reduced demoulding forces compared to the industry standard steel moulds in the literature and their material-jetted counterparts. Minimal changes in the surface textures of the material-jetted inserts were found, which could potentially permit their prolonged usage. Significant correlations between surface temperatures and demoulding energies were demonstrated.Originality/valueThe research presented here addresses the very topical issue of demoulding characteristics of soft, rapid tools, which affect the quality of prototyped products and tool durability. This was done using state-of-the-art, high-speed sensing technologies in conjunction with surface metrology and their durability for the first time in the literature.

Investigation of customer behavior regarding circular fashion

Circular fashion aims to reduce the environmental impact of the fashion industry by creating a closed-loop system where waste is minimized and materials are reused, recycled, refurbished, remanufactured etc. Consumer behavior is crucial for this movement as individuals have the potential to utilize circular economy initiatives (i.e., reuse, second hand etc.). Adopting a circular mindset and making sustainable choices can significantly contribute to a more environmentally friendly fashion industry. However, barriers such as lack of education and awareness hinder the widespread adoption of sustainable fashion practices. This study utilized a questionnaire administered to 650 individuals in Cyprus to examine textile disposal practices and consumers' willingness to pay for circular fashion products. The questionnaire, comprising 13 questions, targeted participants primarily aged 20 to 49, most of whom held university or master's degrees. Results indicated a notable willingness among participants to engage in sustainable practices, with many expressing a desire to purchase from second-hand or rental clothing markets and support recycled clothing initiatives. Spearman correlation analysis revealed a strong positive correlation between educational level and knowledge of sustainable fashion (0.946), circular economy (0.919), and circular fashion (0.910). These findings underscore the importance of education in promoting sustainability within the fashion industry. Understanding consumer knowledge levels regarding sustainable and circular fashion can enhance efforts to educate the public on the impact of their purchases on environmental, economic, and social sustainability. This research provides valuable insights into the correlation between consumer characteristics, education, and their needs concerning circular fashion.

Bio-chelate assisted leaching for enhanced heavy metal remediation in municipal solid waste compost

Municipal solid waste compost, the circular economy's closed-loop product often contains excessive amounts of toxic heavy metals, leading to market rejection and disposal as waste material. To address this issue, the study develops a novel approach based on: (i) utilizing plant-based biodegradable chelating agent, l-glutamic acid, N,N-diacetic acid (GLDA) to remediate heavy metals from contaminated MSW compost, (ii) comparative assessment of GLDA removal efficiency at optimal conditions with conventional nonbiodegradable chelator EDTA, and (iii) enhanced pre- and post-leaching to evaluate the mobility, toxicity, and bioavailability of heavy metals. The impact of treatment variables, such as GLDA concentration, pH, and retention time, on the removal of heavy metals was investigated. The process was optimized using response surface methodology to achieve the highest removal effectiveness. The findings indicated that under optimal conditions (GLDA concentration of 150 mM, pH of 2.9, retention time for 120 min), the maximum removal efficiencies were as follows: Cd-90.32%, Cu-81.96%, Pb-91.62%, and Zn-80.34%. This process followed a pseudo-second-order kinetic equation. Following GLDA-assisted leaching, the geochemical fractions were studied and the distribution highlighted Cd, Cu, and Pb's potential remobilization in exchangeable fractions, while Zn displayed integration with the compost matrix. GLDA-assisted leaching and subsequent fractions illustrated transformation and stability. Therefore, this process could be a sustainable alternative for industrial applications (agricultural fertilizers and bioenergy) and social benefits (waste reduction, urban landscaping, and carbon sequestration) as it has controlled environmental footprints. Hence, the proposed remediation strategy, chemically assisted leaching, could be a practical option for extracting heavy metals from MSW compost, thereby boosting circular economy.

Putting people at the centre of the circle: an agenda for behavioural research on the circular economy

In a discourse characterised by technical innovation, alternative business models and material flows, the seemingly mundane, everyday forms of individual action toward circularity that can and are being taken by members of the public can sometimes feel overlooked. Whilst the importance of behaviour change is often acknowledged, in-depth conceptual engagement around circular behaviours remains uncommon in the field of circular economy research. In this perspective article we advocate for a person-centred perspective on circular behaviours, viewing people as not just consumers or users of circular products, but as individuals, nested within social groups, whose everyday, yet complex, relationships with material goods must undergo a shift if a circular economy is to be achieved. Drawing on insights from the wider field of pro-environmental behaviour research, we explore how we conceptualise circular behaviours themselves and how the behavioural theories we apply may constrain the ambition of the policy action our research supports. In doing so, we set out a person-centred agenda for research on circular behaviours, recommending: (1) greater application of systems-oriented approaches; (2) conceptual development on categorising circular behaviours, and (3) interdisciplinary efforts to integrate theory from across social science disciplines to underpin behavioural analyses and public engagement and action on the circular economy.