Search Results (365)

Industrial symbiosis is widely proposed as a mechanism for the circular bioeconomy, but its evidence base is dominated by dense industrial settings. This study examines how symbiosis can emerge in a low-density industrial territory and which conditions prevent technically plausible exchanges from materialising. A region in North-Eastern Portugal (26 municipalities, 10,908 km², 28.3 inhabitants/km²) was examined through four instruments: territorial characterisation from official registers; a population of 89 firms in forestry, mushroom production and biocomposites; a structured survey; and documentary triangulation for the non-responding biocomposite sector. Forest and shrubland occupy 58.0% of the territory, and established institutional and R&D capacity is present. Conversion capacity, however, is fragmented and functionally mismatched with the intermediate processing required for higher-value material exchange, and no established inter-sectoral by-product exchange among the three chains was identified: one mushroom producer imports processed lignocellulosic substrate from Spain, while local forestry residues are shredded on site. The constraints identified are functional conversion capacity, aggregation, information and facilitation; declared willingness to transfer was present among most surveyed firms and was not the limiting condition observed, while relational readiness in its broader sense was not assessed. Potentially capable organisations exist, but no explicit by-product-exchange facilitation mandate was identified in the institutional sources reviewed, so facilitation appears unassigned rather than unavailable. The findings therefore shift intervention priorities towards the infrastructural and institutional shortfalls identified in the observed cases. Full article

Climate change and increasing pressure on natural resources highlight the limitations of the predominantly linear economic model of production and consumption, and the need for more integrated sustainable approaches. Circular economy (CE) strategies offer a potential alternative, contributing to reduction of emissions and resource conservation, while increasing the resilience of systems to climate shocks. This review examines the relationship between CE, emission reduction, resource efficiency, and climate resilience. A bibliometric analysis was first conducted for the initial subset of reviewed articles obtained from the Web of Science (WoS), following particularly predesigned criteria for inclusion and exclusion, to establish the main conceptual and thematic structures in the literature. Across the 72 studies included in the final review, sectors such as construction, energy, and waste management emerged as prominent application fields, with strategies like reuse, recycling, industrial symbiosis, and product as a service among frequently investigated strategies. The contribution of CE to climate resilience in the current review remains limited. Resilience, however, is often harder to measure and less well-documented. To address this gap, an integrated framework is proposed that brings together indicators of emissions reduction, resource saving, and climate resilience, allowing potential synergies and trade-offs among these dimensions. The findings further highlight the need to move from isolated assessment towards a more systematic interconnected assessment. Full article

Oxygen carriers (OCs) are essential materials in chemical looping technologies for low-carbon hydrogen production; however, the environmental implications of their synthesis remain insufficiently explored. This study presents a gate-to-gate life cycle assessment (LCA) of a chamotte–nickel OC produced via wet impregnation, following ISO 14040/44 guidelines. The functional unit was defined as 1 kg of oxygen carrier (OC), with input material requirements including chamotte, nickel nitrate, and water, as part of the synthesis process. Environmental impacts were modelled using ReCiPe 2016 Midpoint (H). Environmental hotspots varied across impact categories, with wet impregnation and energy-intensive thermal processes showing substantial contributions, while transportation-related burdens were relevant in selected toxicity and resource-related categories. Wet impregnation contributed 38.93% to climate change, approximately 55.6% to ozone depletion, and approximately 95.6% to terrestrial acidification in the modelled inventory. Thermal treatments also contributed substantially to several impact categories, primarily because of their high electricity requirements. Hotspot analysis identified precursor selection, energy supply, and logistics as key drivers of environmental burdens. Qualitative mitigation options include precursor substitution, renewable-energy integration, energy-efficiency improvements, and industrial symbiosis; however, these alternatives were not quantitatively evaluated in the present LCA. These results offer actionable guidance for sustainable OC design and highlight the importance of integrating LCA into early-stage oxygen-carrier design to reduce the environmental burdens associated with material synthesis. Further assessment incorporating OC performance, lifetime, regeneration, and hydrogen yield would be required to determine the implications of these material-level improvements for the environmental performance of hydrogen production. Full article

The valorization of agro-industrial residues and by-products can improve resource efficiency and circularity, but implementation depends on more than technical performance. This scoping review mapped application-oriented valorization routes, their distribution across sectors and scales, and the barriers, facilitators, gaps, and recommendations related to implementation. Following Joanna Briggs Institute guidance and PRISMA-ScR, the Web of Science Core Collection was searched without publication-period or language restrictions. Thirty peer-reviewed studies published between 1996 and 2026 were included. Vegetable oils and oilseeds accounted for 40.0% of the studies, while industrial or plant-level applications represented 30.0%. Energy-based strategies were the most frequent (26.7%), followed by biological and chemical or physicochemical approaches (20.0% each). Implementation was influenced by residue characteristics, production processes, infrastructure, costs, logistics, coordination, regulation, and information availability. Six interconnected implementation domains were identified: technical and operational; economic and financial; logistical; organizational and governance; regulatory and institutional; and scale-up, limitations, and recommendations. The findings indicate that scale-up requires integration of technical, operational, logistical, economic, governance, and institutional conditions. An implementation-oriented perspective is provided to support future assessments, industrial planning, and policy decisions toward circular agro-industrial systems. Full article

The rapid expansion of aquaculture has led to a substantial increase in the generation of organic waste, nutrient-rich effluents, and residual biomass, creating significant environmental challenges while simultaneously providing opportunities for resource recovery within the circular bioeconomy. Environmental biotechnology offers a broad range of solutions for transforming these waste streams into valuable products, including renewable energy, fertilisers, biochar, microbial biomass, and other bio-based resources. However, the practical implementation of these technologies in floating aquaculture systems remains fragmented due to the lack of integrated engineering approaches. This review critically analyses the current state-of-the-art in environmental biotechnology pathways for aquaculture waste valorisation, covering biological, physicochemical, and thermochemical technologies applicable to floating production systems. The assessment covers anaerobic digestion, composting, insect bioconversion, microalgae cultivation, integrated multi-trophic aquaculture, nutrient recovery, hydrothermal carbonisation, and pyrolysis, together with their technological maturity, offshore applicability, and contribution to circular resource recovery. Beyond reviewing existing technologies, this paper proposes the “Circular Floating Aquaculture Systems Engineering Integration Framework” (CFAS-EIF), a systems engineering concept that integrates floating production infrastructure, waste collection, resource recovery technologies, digital management, and circular value chains into a unified architecture. The framework illustrates how environmental biotechnology can be implemented through coordinated engineering integration, enabling the transition from waste management to resource valorisation in offshore aquaculture. The proposed framework provides researchers, engineers, and industry stakeholders with a comprehensive reference for designing next-generation aquaculture platforms that support sustainable resource management, climate change mitigation, and a circular bioeconomy. Full article

Industrial symbiosis is one of the main routes for turning waste streams into useful materials and energy within a circular economy. Little empirical evidence exists, however, on how symbiosis projects are managed within a circular economy project management standard. This exploratory single-case study examines the motivations, implementation, and outcomes of symbiosis initiatives in the water sector, developed by an organisation certified under the XP X30-901 standard and covering treated water, biomethane, thermal energy, and fertiliser recovery. An externally assured indicator series for 2016 to 2025 compares the years before the portfolio was formalised in 2019 with those after certification in 2021. Sludge sent to landfill fell from 16.4% of the total managed in 2016 to zero from 2022, the share sent to agriculture and fertiliser production rose from 46.0% to 64.1% between 2019 and 2023, and the average transfer cost fell from EUR 134.34 to EUR 107.15 per tonne. The standard supported the identification, prioritisation, and monitoring of circular projects, although these outcomes cannot be attributed to it alone. Indicators exposed to hydrological, market, and regulatory conditions proved less stable than those that the organisation controls directly, suggesting that standardisation consolidates controllable outcomes rather than improving overall performance. Full article

The transition to a new industrial paradigm beyond Industry 5.0 demands hyperconnectivity and massive processing, creating a paradox where high computational demand can threaten corporate sustainability goals (ESG). This study aims to structure and prioritize a Multilayer Framework of multicloud technologies to balance disruptive advances, lean optimization, and decarbonization. A mixed, sequential, and exploratory-normative approach was used. Initially, the literature was triangulated with expert panels and suppliers to map 21 technological functionalities, structuring them into four layers of a bidirectional value flow. Then, a hybrid multi-criteria modeling (AHP-TOPSIS) was applied to rank these technologies against five market constraints. Calibration with AHP revealed that Cyber Resilience, approximately 38%, and Process Optimization, approximately 27%, lead executive priorities, surpassing environmental impact or cost efficiency. As a result, the TOPSIS ranking highlighted Human–Machine Symbiosis (BCI/neuroergonomic readiness), Zero Trust architecture, Federated Learning, and GenAI KPI Analytics as the leading functionalities in their respective layers, with Hyper-BPM emerging as a closely associated optimization engine at the governance layer. Finally, the proposed roadmap was assessed using an anonymized industrial Proof of Concept (PoC) in a brownfield advanced manufacturing facility, providing evidence of its operational feasibility for integrating lean optimization with legacy systems and ESG-oriented monitoring. It is concluded that industrial sustainability does not rely solely on green technologies, but on decentralized orchestration along the Edge-Cloud continuum. Environmental gains are therefore more likely to emerge when cyber governance and lean-oriented operational management jointly support decentralized multicloud orchestration. Full article

This study examines the impact of Circular Economy (CE) practices and Industrial Symbiosis (IS) on Sustainable Firm Performance (SFP), while exploring the moderating effect of Institutional Pressure (IP) in achieving Sustainable Development Goals (SDGs). Adopting a quantitative research design, data were collected through a structured questionnaire administered to managers (n = 321) in manufacturing firms involved in sustainability and operations. The proposed conceptual framework was analyzed using Covariance-Based Structural Equation Modeling (CB-SEM), with reliability and validity assessed through Cronbach’s alpha, Composite Reliability (CR), and Average Variance Extracted (AVE), and model fit evaluated using indices such as CFI, TLI, RMSEA, and χ²/df; mediation and moderation effects were tested. The findings reveal statistically significant positive associations between Circular Economy Practices, Industrial Symbiosis, and Sustainable Firm Performance. Institutional Pressure was found to strengthen these positive relationships. The study contributes to the literature by integrating circular economy and industrial symbiosis within a unified SEM framework, offering empirical evidence from a developing economy context, and extending Institutional Theory and the Resource-Based View (RBV) in sustainability research. Practically, the findings suggest that firms should adopt collaborative resource-sharing models, policymakers should reinforce regulatory and normative pressures, and industrial clusters should promote symbiotic networks to enhance waste-to-resource conversion. Full article

The modern energy transition has outpaced the control and optimization frameworks built to govern it. As power and energy systems fragment into webs of renewable generators, storage operators, flexible loads, and carbon-constrained firms, the deterministic, single-optimizer models that once sufficed buckle against nonlinearity, bounded rationality, and strategic conflict among parties who learn and revise as they go. Evolutionary game theory (EGT), which traces how strategies propagate through populations by imitation and selection rather than instantaneous optimization, offers a route through this difficulty—one this review develops across three scales of low-carbon coordination central to cleaner production: enterprise-level industrial symbiosis, system-level smart energy operation, and market-level carbon governance. We synthesize three decades of theory alongside the recent fusion of EGT with artificial intelligence, where deep reinforcement learning approximates high-dimensional payoffs, federated learning lets rival firms co-train models without surrendering proprietary data, and blockchain underwrites decentralized mechanism execution. The synthesis is accompanied by two illustrative numerical case studies, constructed for this review rather than drawn from the surveyed literature, whose quantitative outputs are reported below as demonstrations of modeled behavior rather than as empirical measurements. In the first of these, cooperative emergence in industrial symbiosis hinges on critical thresholds that travel from 0.15 to 0.75 as subsidies and transaction costs vary, with anchor-enterprise targeting accelerating cooperation 2.4-fold while cutting outcome variance 3-fold. In smart energy coordination, AI-enhanced learning buys 32 to 41% faster convergence, yet pays 25 to 39% larger oscillations—a speed–stability tension whose resolution lives in a narrow learning-rate band near 0.08 to 0.12, outside which either sluggishness or instability takes hold. Carbon-market behavior turns on price thresholds: emitters switch abruptly from buying quotas toward investing in abatement once the clearing price clears firm-specific triggers, a discrete state switch that smooth equilibrium analysis misses entirely. Across all three domains, fragmented data, path dependence, and regime-switching dynamics recur as the binding constraints on modeling and on governance alike. Four mechanisms prove invariant to scale—the decisive weight of initial conditions, the catalytic leverage of well-positioned anchor agents, the equilibrium-shaping force of institutional design, and the computational reach added by AI integration—which suggests that insight earned in one domain transfers to the others. We close by mapping open problems in heterogeneity modeling, verification under deep uncertainty, and the still-unrealized coupling of digital twins with privacy-preserving learning. EGT emerges not as retrospective description but as prospective guidance for the cooperative transitions on which credible decarbonization depends. Full article

The transition to a circular economy (CE) is central to achieving SDG 12, yet institutional transformation varies significantly across countries. This study conducts a comparative institutional analysis of CE transitions in China and Russia to quantify Russia’s institutional lag and assess the maturity of both systems in the context of SDG indicator 12.5.1 (Circular Material Use Rate—CMUR). Drawing on neo-institutional theory, multi-level governance, and institutional trap theory, we develop an original methodology that computes institutional lag through three key milestones, an integrated maturity index across eight institutional components, and CMUR estimates based on official statistics, legislative acts (1998–2025), and industry reports. Our results show that Russia’s average institutional lag relative to China is 15.3 years: Russia’s 2024 municipal solid waste recycling rate (13.9%) matched China’s 2009–2010 level, while China achieved Russia’s 25% target for 2030 in 2018. The integrated maturity index is 8.25 for China versus 5.25 for Russia, with the largest gaps in industrial symbiosis, R&D and human capital, and international integration. Russia’s CMUR stands at 5–7%, compared to 25–30% in China. We also demonstrate that Russia’s high recycling growth is driven by a low-base effect and is not evidence of institutional efficiency; the compound annual growth rate (CAGR) of Russian recycling volume (33.0%) significantly exceeds China’s (13.1%), but this reflects the much lower starting point rather than systemic maturity. We conclude that without systemic institutional reforms—including eco-industrial parks, green finance, and competence centres—Russia will remain at an early CE stage, failing to substantially contribute to SDG 12 by 2030. Full article

Smart cities have emerged as a strategic approach to enhancing urban sustainability through the integration of digital technologies, intelligent infrastructure, and data-driven governance. However, limited research has comprehensively examined how technological, institutional, governance, and contextual factors interact to influence sustainability outcomes in industrial-city settings, particularly in Saudi Arabia. This study develops an integrated conceptual framework for sustainable smart industrial cities through a qualitative research design based on a systematic screening and synthesis of the literature, complemented by a contextual analysis of the Dammam Metropolitan Area (DMA) as an illustrative urban-industrial case under Saudi Vision 2030. A total of 86 articles, reports, and website materials were identified and screened, of which 49 sources met the inclusion criteria and were synthesized to develop the proposed framework. The analysis examined five interrelated components: smart-city applications, institutional governance, implementation conditions, contextual barriers and opportunities, and sustainability outcomes across three dimensions: environmental, social, and economic. The findings suggest that the effectiveness of smart-city applications depends not only on technological innovation but also on institutional governance, digital readiness, stakeholder participation, integrated planning, and supportive regulatory environments. The study further identifies fragmented governance, limited institutional coordination, cybersecurity risks, and high infrastructure costs as key implementation barriers, while highlighting opportunities associated with Saudi Vision 2030, digital-transformation initiatives, and circular-economy principles. The principal contribution of the study is the development of an integrated conceptual framework that explains the interactions among these five components and provides a theoretical foundation for future empirical validation, as well as conceptually informed guidance for policy development and planning in Saudi Arabia and comparable industrial-city contexts. Full article

From the perspective of symbiosis theory, collaborative work safety governance in industrial parks can be understood as a dynamic multi-actor symbiotic system jointly composed of the park management committee, leading enterprises, and small and medium-sized enterprises. To examine how reciprocal symbiosis among multiple actors affects system-level safety performance and sustainable operation, this study develops a differential game model in which the work safety level of the industrial park evolves dynamically over time. The model comparatively analyzes the work safety efforts, discounted payoffs of symbiotic units, and the overall work safety level of the park under different decision-making mechanisms and reciprocal symbiosis modes. The results show that: (1) under the leading-enterprise-dominated mode, as the coefficient of work safety resource sharing increases, the overall work safety level of the park correspondingly improves; however, once this coefficient exceeds a certain threshold, it becomes unfavorable to the further growth of the leading enterprise’s own benefit; (2) under the park-management-committee-led mode, as the cost-sharing coefficient increases, the overall work safety level of the park continues to improve, but an excessively high cost-sharing coefficient weakens the incentive for the park management committee to increase its benefit; and (3) under certain conditions, the leading-enterprise-dominated mode, the park-management-committee-led mode, and the deep collaboration mode can all improve both the park’s work safety level and the discounted payoffs of symbiotic units, but the deep collaboration mode performs best in enhancing the overall work safety level and the total system payoff. Compared with the park-management-committee-led mode, the leading-enterprise-dominated mode is more sensitive in its impact on the total payoff of the industrial park. These findings indicate that sustainable work safety improvement in industrial parks cannot rely solely on increasing governance inputs or on the actions of a single actor. Instead, it requires a system-wide balance among safety performance, economic efficiency, resource-sharing sustainability, and the long-term stability of collaborative relationships. The study provides a system-oriented theoretical basis for optimizing reciprocal symbiosis mechanisms and promoting the sustainable development of industrial parks. Full article

Energy industrial zones can act as a transformative model for industrial decarbonization by integrating renewable energy infrastructure directly with industrial production. By combining energy industrial zones with the energy community framework and peer-to-peer (P2P) energy trading, this study proposes a pathway toward 100% renewable energy sources. The model was tested using a techno-economic assessment applied to the Bravar-Jasenice case study in Croatia featuring 12 MW of solar PV, 10 MW of wind power, and a 9.3 MW biogas cogeneration plant. This integrated approach can achieve 80–90% energy self-sufficiency and reduce electricity expenditures for participating enterprises by approximately 15%. Furthermore, the system facilitates an annual reduction of roughly 20,000 tonnes of CO₂ emissions, thus directly supporting European Green Deal objectives. The study also highlights the potential for industrial symbiosis, including green hydrogen production, data centre integration, and waste heat recovery. Ultimately, the proposed framework provides a robust strategy for enhancing industrial competitiveness and ensuring energy security through localized, sustainable energy management. Full article

Do enterprises with high tax contributions exhibit green transformation inertia due to the alignment of government and enterprise interests? Using data from the Chinese A-share market, this paper finds that high tax contributions significantly inhibit corporate green transformation. The mechanism lies in the fact that local governments implement inclusive regulation for high-tax-contribution enterprises, reducing their environmental compliance pressure and cutting environmental protection investment; at the same time, the halo effect of tax contributions provides a cover for enterprises’ low-quality environmental information disclosure. Exclusion analysis shows that financing constraints are not a limiting factor. Heterogeneity analysis indicates that the above effects are more prominent in samples with close government–enterprise connections, fierce industry competition, and loose local environmental regulations. Economic consequences show that insufficient green transformation caused by high tax contributions ultimately damages enterprises’ environmental performance and long-term sustainable development capabilities, and significantly increases stock price crash risk. Optimizing internal management and external supervision within enterprises can help mitigate this negative effect. This paper reveals the hidden obstacles to corporate green transformation under the symbiosis of government and enterprise interests, providing a new perspective for understanding the complexity of environmental governance. Full article

Industrial water reuse and resource recovery are essential for advancing circular economy principles in water-intensive industries. Despite technological maturity, large-scale implementation continues to lag due to high costs, effluent variability, integration challenges, and weak economic returns. Going beyond technology, this paper critically examines what truly works at scale, why most systems fail, and how to build resilient multi-stream recovery solutions. Drawing on major European demonstration projects (INCOVER, RESURGENCE, MEloDIZER) and recent literature, the paper demonstrates that multi-stream systems significantly outperform single-resource approaches. Success depends less on individual technologies and more on modular design, digital integration, sector-specific adaptation, and supportive governance. The study introduces the Industrial Circular Performance Framework (ICPF) and provides clear, actionable pathways to move from promising pilots to bankable, resilient circular industrial water systems. Full article