Search Results (1,198)

Ceramic production generates large quantities of fired waste that is durable, non-biodegradable, and increasingly difficult to manage through conventional waste disposal practices. This study analyzes how ceramic waste is transformed into sustainable value in Jingdezhen, China, a city where ceramic production and cultural heritage have developed over more than a millennium. Using a qualitative multiple-case design, this study examines representative cases from three ceramic waste reutilization pathways: industrial reuse, environment-oriented reuse, and craft-based artistic reuse. The analysis shows that ceramic waste creates sustainable value through three interconnected processes: material transformation, economic activation, and cultural re-signification. Industrial cases primarily promote resource recovery and product innovation; public and environmental projects improve environmental awareness by integrating ceramic waste into urban spaces; and artistic practices reinterpret discarded ceramics as a medium for historical reflection, cultural expression, and public engagement. Based on these findings, the study proposes a material economic cultural analytical framework that explains how these value dimensions interact to transform ceramic waste from an environmental burden into a strategic resource. This study goes beyond documenting feasible ceramic waste recycling models by demonstrating that effective circular resource management in heritage-based industrial regions depends not only on technical recycling practices but also on cultural connotations and public recognition, which, together, generate value across environmental, economic, and cultural significance. These findings extend the scope of circular economy research by demonstrating a viable pathway for heritage-based industrial regions to leverage their own cultural heritage in transforming ceramic waste into environmental, economic, and cultural value. They also provide a practical model for other heritage-based regions seeking to align waste management with sustainable development. Full article

Water-based enhanced oil recovery (EOR) techniques continue to attract interest because of their technical practicality and economic feasibility. Hybrid low-salinity surfactant flooding is a promising EOR strategy for carbonate reservoirs; however, the coupled effects of low-salinity brine, surfactant addition, wettability alteration, electrostatic modification, and capillary pressure reduction remain difficult to isolate. This study investigates hybrid low-salinity surfactant flooding in restored tight carbonate cores using integrated experimental measurements and core-scale numerical modeling. The experimental workflow included oil–water interfacial tension (IFT), zeta potential, contact angle measurements using a custom-designed HPHT imbibition cell, and reservoir-condition HPHT coreflooding under sequential and standalone injection schemes. The sequential flood evaluated the transition from seawater (SW) to 1%diluted seawater (1%dSW) and then to 1%dSW+A-1 surfactant, while standalone floods assessed the direct displacement performance of 1%dSW and 1%dSW+A-1. Dilution from SW to 1%dSW increased IFT from approximately 10.2 to 14.9 mN/m, indicating that the recovery improvement during 1%dSW injection was not caused by IFT reduction. Instead, zeta potential and contact angle results indicated progressive electrostatic modification and wettability alteration toward a less oil-wet state. The contact angle decreased from approximately 123° for SW to 101° for 1%dSW and further to 84° after A-1 addition. In contrast, 1%dSW+A-1 reduced IFT sharply to approximately 0.178 mN/m at 0.2 wt%, lowering the estimated capillary pressure magnitude and weakening capillary trapping. Sequential coreflooding showed that SW recovered 42.65% OOIP, followed by an additional 24.21% OOIP from 1%dSW and 9.11% OOIP from 1%dSW+A-1. Standalone 1%dSW and 1%dSW+A-1 recovered approximately 58.44% and 65.82% OOIP, respectively. Core-scale models reproduced the main recovery and pressure drop trends using zeta potential-guided relative permeability and capillary pressure functions supported by surface complexation modeling concepts. Overall, 1%dSW+A-1 improved oil displacement through a synergistic mechanism in which low-salinity brine stabilized the water film and altered wettability, while A-1 surfactant reduced IFT and weakened capillary trapping. The integrated experimental and modeling workflow provides a mechanistic basis for evaluating hybrid low-salinity surfactant flooding and for linking laboratory-measured interfacial properties to effective core-scale rock–fluid functions. Full article

Autonomous vehicles (AVs) are moving from pilots to regular urban service, yet the speed of large-scale implementation remains uncertain. While prior research emphasizes technological feasibility and adoption, less attention has been paid to the socio-technical dynamics that constrain deployment. This study examines how unintended consequences shape the pace of AV implementation in cities. Drawing on a mixed-methods design combining a structured scoping review with 18 expert interviews, interrelated dynamics are identified across institutional, behavioral, economic-platform, spatial, and normative-societal domains. The findings indicate that implementation speed is not determined by technology alone but emerges from reinforcing feedback loops that generate systemic frictions, including governance lag, demand rebound, spatial bottlenecks, and legitimacy challenges. The study advances a systems-oriented framework that conceptualizes implementation speed as an emergent property of socio-technical dynamics, highlighting the importance of adaptive and anticipatory governance for sustainable urban mobility transitions. Full article

Reliable and sustainable access to energy continues to pose a significant challenge for rural farms in African underprivileged areas, where traditional diesel generators are both economically and environmentally unfeasible. This research explores the potential of pumped thermal energy storage (PTES) systems utilizing a Rankine cycle for the preservation of farm produce, analyzing four configurations of reversible heat pump–organic Rankine cycle (HP–ORC) systems that employ R1234ze(E) as the working fluid: hot-storage cooled HP mode, air-cooled HP mode, basic ORC mode, and ORC mode with integrated electrical heaters. Despite the exploration of hybrid HP–ORC and reversible PTES configurations in the existing literature, there remains a significant lack of research focusing on their feasibility for energy services in rural agriculture, and the literature data remains insufficient for comprehensive decision-making on deployment for small-scale applications in rural settings. To bridge this gap, the thermodynamic performance was evaluated for the PTES configurations through exergy analysis, to measure system irreversibility and component losses. Also, an exergoeconomic assessment was conducted using the Specific Exergy Costing (SPECO) method, while environmental impacts were examined with Eco-Indicator 99, aimed primarily at decision-making for real-life application. The results indicate that the ORC mode with electric heater achieved the highest exergy efficiency at 31.7%, surpassing the hot-storage cooled HP mode by approximately 11 percentage points. The air-cooled ORC with electric heaters exhibited a thermal efficiency of 26.6% and reduced economic losses, while also demonstrating significantly lower environmental degradation compared to the hot-storage HP mode (1327 mpts/s). These results suggest that air-cooled HP-ORC configurations provide an optimal balance of technical, economic, and environmental performance, thereby promoting sustainable, localized energy solutions for rural agricultural practices. Full article

Existing urban residential buildings contribute substantially to operational energy use and carbon emissions in the building sector, making low-carbon retrofitting a key approach to improving the performance of the existing housing stock. This study conducts a bibliometric and systematic review of research on low-carbon retrofitting of existing urban residential buildings in China. Journal articles published between 2015 and 2025 were retrieved from Web of Science and Scopus, and 91 studies were retained after screening. Bibliometric analysis was used to examine annual publication trends, source distribution, keyword co-occurrence, thematic evolution, and organizational collaboration. The systematic review further synthesised evidence on retrofit policies, technical measures, and performance evaluation methods. The results indicate a clear increase in publications in recent years, with research attention shifting from basic energy-saving measures towards multi-objective optimization, carbon reduction, and thermal comfort improvement. The review suggests that China’s residential retrofit policies can be understood as a multi-level framework supporting retrofit implementation. Retrofit strategies have gradually shifted from individual measures towards integrated retrofit packages, while performance evaluation has expanded from energy-saving assessment to broader considerations of carbon emissions, occupant comfort, and economic feasibility. The review highlights the need for more consistent evaluation boundaries, stronger integration of lifecycle carbon accounting and occupant behaviour, and climate-responsive retrofit strategies. These findings provide a structured basis for comparing retrofit approaches, strengthening the connection between policy and technology, and supporting decision-making in large-scale residential retrofit programmes. Full article

Open burning of agricultural residues remains a significant source of air pollution and greenhouse gas emissions in Southeast Asia. This study evaluated a community-scale smokeless vertical charcoal kiln for biochar production from corncob residues under practical operating conditions. Carbonization at 415–435 °C for 150–180 min produced biochar yields of 23.3–28.3%, with the 150 min treatment giving the highest yield. The biochar exhibited high carbon content (71–71.5%), low volatile matter (15.7–16.7%), fixed carbon content of 51–54%, and moderately alkaline pH (8.97–9.08). Atomic H/C and O/C ratios (approximately 0.55 and 0.27) indicated moderate aromaticity and stability consistent with IBI Class 1 criteria, while SEM revealed a macropore-dominated porous structure. Theoretical carbon sequestration potential was estimated at 0.69–0.74 tCO₂-eq per tonne of dry feedstock. These findings demonstrate the technical feasibility of community-scale smokeless biochar production and provide physicochemical characterization of the resulting biochar, suggesting potential relevance for carbon storage and soil amendment; however, agronomic performance and emissions require direct evaluation, and results are specific to corncob feedstock. Overall, this work contributes to sustainable agricultural waste management by demonstrating a low-cost, community-accessible pathway that simultaneously supports climate change mitigation, air quality improvement, and socio-economic accessibility for smallholder farming systems in Southeast Asia. Full article

Polyhydroxybutyrate (PHB), a microbial polyester belonging to the polyhydroxyalkanoate (PHA) family, has emerged as one of the most promising biodegradable alternatives to conventional petroleum-derived plastics. Its inherent marine biodegradability (typically mineralizing within months depending on material geometry and ambient temperature), biocompatibility, and ability to be synthesised from renewable and waste-derived feedstocks position PHB as a key candidate for supporting the transition towards a circular bioeconomy. Despite these advantages, widespread commercial adoption remains limited by high production costs, processing challenges, and performance constraints relative to established commodity plastics and competing biopolymers. This review critically evaluates the current state of PHB development from the perspective of sustainable commercialisation. Key aspects discussed include microbial biosynthesis pathways, feedstock selection, upstream fermentation strategies, downstream recovery technologies, and technoeconomic considerations influencing industrial feasibility. The intrinsic thermal, mechanical, and degradation characteristics of PHB are examined alongside modification approaches such as copolymerisation, polymer blending, plasticisation, and composite reinforcement that have been developed to overcome certain inherent physical–mechanical properties, narrow processing windows, and limited functional performance. Furthermore, characterisation methodologies, environmental degradation behaviour, and emerging industrial applications are assessed within the context of market requirements and sustainability objectives. Particular emphasis is placed on identifying the interconnected technical and economic bottlenecks that continue to hinder large-scale deployment, including feedstock costs, fermentation scalability, downstream processing expenses, and material performance trade-offs. By integrating advances across the entire PHB value chain, this review highlights current opportunities, remaining challenges, and future priorities required to enable the sustainable and economically viable commercialisation of PHB-based materials. Full article

Background: Road transport accounts for 73% of transport-related greenhouse gas emissions within the EU, 27% of which are attributable to heavy-duty vehicles. In order to reduce emissions in the area of heavy-duty commercial vehicles, electrifying the fleet offers a perspective. As part of a cooperation between TU Berlin, Siemens and BLG Logistics within the Mobility2Grid research campus, an analysis was carried out to determine how an exemplary BLG depot for regional logistics transport with six diesel trucks can be converted to battery–electric trucks. Methods: This analysis was conducted under a fixed depot schedule with defined dwell times and charging opportunities, with the aim of developing practical recommendations for the acquisition of suitable vehicles and infrastructure. To this end, simulations were carried out using the eFlips consumption and depot simulation software developed at TU Berlin. Results and Conclusions The results show that electrification for regional logistics transport can already be fully implemented with the current state of the art technology and that neither very large batteries nor very high charging powers are required for technically feasible and economically balanced operation. Notably, the cost-optimal battery capacities identified (approximately 200–230 kWh) are currently smaller than those of commercially available 40 t electric trucks, revealing a gap between the model-optimal configuration and present market offerings. Based on the identified optimal configuration, a life cycle assessment (LCA) is conducted to evaluate the environmental impact of fleet electrification. Over a 10-year lifetime, the battery–electric fleet reduces cumulative greenhouse gas emissions by approximately 53% compared to the diesel baseline, with operational-phase savings clearly outweighing higher production-related emissions. The combined techno-economic and environmental assessment provides a structured decision basis for depot-centered fleet electrification. Full article

The transition from traditional siloed to intelligent cities allows for the deployment and management of information and communication technologies in the urban context to be driven by holistic sustainability requirements rather than technical ones such as feasibility and fragmented, siloed operational patterns. This work proposes a multi-dimensional decision-making framework to manage a smart city as an urban cognitive Cyber–Physical System (CPS) across environmental, economic, and social sustainability pillars, metrics and their trade-offs. A methodology based on Deep Reinforcement Learning (DRL), specifically adopting Deep Q-Networks (DQNs), is proposed to represent and assess sustainability pillar dependencies and their interplay. A case study on Low-Power Wide-Area Network planning, deployment and management in a Sicilian municipality has been developed to demonstrate the effectiveness of the proposed approach in dealing with the dynamics and non-linear dependencies of the sustainability pillars. Full article

Locally available biomass resources offer a sustainable pathway for supporting traditional health practices at the community scale. This study designed, developed, and evaluated a biomass-fueled herbal steam generation system using Melaleuca leucadendra leaves for community-based therapeutic applications in the U-Tapao River Basin, Songkhla Province, Thailand. The system was developed based on appropriate technology principles aligned with the Bio–Circular–Green (BCG) economic model, integrating a biomass combustion stove with a steam generation unit. Performance was assessed using the Water Boiling Test (WBT) to measure thermal efficiency, boiling time, and steam generation capacity. Results showed that the developed system significantly improved thermal efficiency and reduced boiling time compared with traditional methods (p < 0.01), attributable to enhanced combustion characteristics and heat transfer efficiency. Field trials across two herbal steam room configurations confirmed stable therapeutic temperatures of approximately 40 °C sustained over 30–35 min sessions. The system is technically feasible, energy-efficient, and practically viable for community-scale deployment. This work demonstrates that integrating renewable biomass energy with traditional herbal therapy can provide a replicable, sustainable model for local resource utilization and community-based economic development. Full article

Nitrogen (N) and Phosphorus (P) are essential macronutrients whose unsustainable extraction and use pose growing environmental and geopolitical challenges. In the European Union, tightening regulatory frameworks, including the Urban Waste Water Treatment Directive (EU 2024/3019) and the Farm to Fork Strategy, have positioned nutrient recovery as a fundamental pillar of the circular economy. Despite the availability of mature technologies, comprehensive techno-economic assessments applied comparatively across multiple industrial sectors remain scarce. This study addresses that gap by evaluating the economic feasibility of five nutrient recovery systems across European waste valorization case studies: ammonia stripping from digestate (Spain), sewage sludge composting (Latvia/Lithuania), whey valorization via ultrafiltration and reverse osmosis (Hungary), algae-based dairy wastewater treatment (Slovakia), and pyrolysis of sewage sludge (Denmark). A structured data collection methodology was applied to assess capital expenditures (CAPEX), operational expenditures (OPEX), mass and energy flows, and nutrient recovery yields. Results demonstrate that all five systems show technical operability and economically relevant cost structures, with unit treatment costs ranging from €0.005/kg to €1.60/kg of waste treated, supporting their further development and scale-up as viable nutrient recovery pathways. N recovery was prioritized in most configurations, while P was predominantly co-recovered in solid residues. The findings provide a cross-sectoral comparative framework to support decision-making in the transition towards sustainable nutrient management and circular economy models. Full article

The integration of renewable energy with energy storage units is a key technical approach in enhancing the safety, sustainability, and economic feasibility of industrial energy supply systems. However, the transformation of distributed energy systems (DESs) in chemical energy systems will encounter challenges in capacity configuration and scheduling. Additionally, the high initial investment and long return period lead to conflicts of interest among enterprises, governments, and the public during the energy structure transformation process, hindering the initiative of enterprises to carry out the transformation. To address these, this study proposes an integrated energy system transformation plan based on full life cycle assessment (LCA), considering both economic and environmental goals. A two-layer optimization framework (NSGA-II for capacity configuration and CPLEX for daily scheduling) is established, along with an evolutionary game model for policy analysis. The system combines solar, wind, gas, and storage to meet continuous industrial demand. The optimal scheme achieves a 2.64-year investment payback period, a 435.8% return rate, and a carbon intensity of 0.234 ton CO₂/MWh, 9% lower than a pure fossil scheme. The evolutionary game model balancing enterprise-government-public interests identifies optimal carbon tax and subsidy policies to promote a widely beneficial transformation. Full article

Almond processing byproducts are rich in bioactive polyphenols but severely underutilized due to inefficient conventional extraction methods. This study presents the first systematic optimization of an integrated ultrasound-assisted enzymatic extraction and AB-8 macroporous resin purification process for almond hull polyphenols, addressing the limitations of low yield, high impurity content, and bioactivity loss in traditional approaches. Extraction parameters were optimized via single-factor experiments combined with Box–Behnken response surface methodology, while purification conditions were refined through static and dynamic adsorption–desorption tests. Structural characterization and antioxidant evaluation were performed using Ultraviolet-Visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assays. Under optimal conditions, the polyphenol yield reached 23.67 mg/g. After purification, polyphenol purity increased 5.88-fold, flavonoid purity improved 4.62-fold, and DPPH/FRAP antioxidant activities were enhanced 5.0-fold and 6.5-fold, respectively. Purified polyphenols retained intact phenolic structures and exhibited a loose porous microstructure. This green process provides a technical basis for high-value utilization of almond hulls. Limitations include lack of polyphenol monomer identification, in vivo efficacy validation and industrial economic feasibility assessment. Full article

The increasing generation of wood ash (WA) from biomass combustion presents both an environmental challenge and an opportunity for sustainable resource utilization. This review provides a comprehensive assessment of recent advances in the valorization of WA for the development of sustainable engineering materials within a circular economy framework. Unlike previous studies that primarily focus on isolated applications of WA, this work integrates multiple technical dimensions, including material characterization, advanced manufacturing technologies, mechanical performance evaluation, computational modelling, and industrial commercialization pathways. Wood ash typically exhibits alkaline characteristics (pH 9–13.5) and particle sizes ranging from 1 to 1000 µm, enabling its application in a wide range of material systems. In cementitious materials, partial replacement of cement with WA (0.10–20%) generally improves mechanical performance, whereas excessive incorporation may reduce structural integrity. The high silica content (>62%) in certain WA types also enables its utilization in lightweight glass systems and radiation-shielding materials. Furthermore, WA has emerged as a promising functional filler in polymeric and ceramic composites, where additions above 0.5% can enhance dynamic mechanical properties and thermal stability. The review also examines standardized inspection and testing procedures, including quality control (QC) and quality assurance (QA) frameworks based on American Society for Testing and Materials (ASTM), Canadian Standards Association (CSA), and European standards, to ensure the reliability of WA-derived materials. Recent developments in artificial intelligence, machine learning, and computational modelling are highlighted for predicting mechanical behavior, optimizing processing parameters, and enabling digitalized manufacturing systems. In addition, circular manufacturing strategies and economic evaluation models, including break-even analysis, are discussed to assess the industrial feasibility of WA-based products. By integrating circular economy principles with materials engineering, digital technologies, and economic assessment, this review establishes a holistic framework for transforming wood ash from an industrial residue into value-added sustainable materials for construction, energy, and advanced composite applications. Full article

The industrial sector accounts for 34% of global energy consumption, of which heat accounts for 74%, predominantly derived from fossil fuels. Solar Heat for Industrial Processes (SHIP) offers a viable decarbonisation route for low-to-medium temperature applications (80–250 °C)—a range that includes processes such as tequila production. Yet integrated techno-exergo-economic assessments for small-scale, modular systems in agro-industrial contexts remain scarce. This study presents a technical, thermodynamic, and economic evaluation of a 2.5 MW_th parabolic trough collector system with thermocline thermal energy storage, integrated into a tequila production facility in Jalisco, México. A parametric analysis across seven solar multiple configurations identifies $SM=1.258$ as the economic optimum, yielding an annual solar fraction of 35%, a CO₂ reduction of 33.5%, a levelised cost of heat of 75.19 USD/MWh_th (16.3% below the fuel-oil baseline), and a payback period of 13.39 years under full accelerated depreciation. The system’s exergy efficiency (23–28%) is nearly four times that of the stand-alone boiler (6.31%); the analysis further quantifies diminishing returns beyond $SM\approx 1.4$ and demonstrates that México’s accelerated depreciation provision substantially broadens the economically feasible design space. These findings provide a replicable techno-exergo-economic framework for SHIP integration in gas-constrained, high-irradiation industrial regions, supporting decarbonisation efforts in emerging economies. Full article