Search Results (6,602)

The cement industry is one of the most energy- and emission-intensive sectors and plays a crucial role in achieving climate neutrality and sustainability objectives. This study examines waste management practices in cement production within the framework of the circular economy and low-carbon transition, with particular emphasis on Polish cement plants operating under EU environmental regulations. Particular attention is given to the use of waste as alternative fuels and secondary raw materials, as well as to the economic and environmental implications of EU climate policy instruments. The research methodology includes an analysis of key emission sources such as clinker production, fuel combustion, and raw material transport and an evaluation of technological and organizational measures aimed at improving energy efficiency and reducing emissions. The empirical analysis is based primarily on operational observations from selected Polish cement plants operating under EU ETS conditions and combines plant-level operational evidence with comparative sectoral data and scenario-based techno-economic assessments related to selected low-carbon technologies. The results suggest that increasing the use of waste-derived fuels and materials may contribute to emission reduction, lower reliance on non-renewable resources, and improved circularity in cement production systems operating under advanced regulatory conditions. Furthermore, the findings highlight the potential for synergies between environmental performance and economic competitiveness. The study underscores the importance of coherent regulatory frameworks and continued investment in low-emission and circular technologies to ensure the long-term sustainability and viability of the cement industry. Full article

To investigate the carbon footprint of bamboo-based activated carbon from different manufacturing pathways, this research evaluated cradle-to-gate manufacturing emissions under a unified system boundary and allocation baseline based on primary data from a 10,000 t/year continuous industrial production line. An LCA model was constructed and verified using an allocation ratio interval scanning method. Results showed that carbon footprints of granular, powdered, and extruded activated carbons were 184.76 kg CO₂ e/t kg CO₂ e/t, 236.75 kg CO₂ e/t, and 293.36 kg CO₂ e/t. Although these products shared identical carbonization and steam activation units, the carbon footprints from milling, molding, and binder inputs accounted for 25.01%, 41.48%, and 52.77% of the total emissions. Internal thermal energy recovery via by-product gas recycling decreased emissions by 81.7%, 77.7%, and 73.8%, respectively. Compared with traditional coal-based alternatives, bamboo-based products achieved a reduction in emissions of about 95%. This study provides scientific guidance for the low-carbon production process of bamboo-based activated carbon and demonstrates the potential of biomass substitution for climate change mitigation. Full article

An effective tourism carbon emission message can promote the willingness to support boosting policies of tourism carbon reduction. However, the factors that contribute to an effective tourism carbon emission messages are not well understood. Through three scenario-based experiments, we reveal the congruity effect between message framing and language style in tourism carbon emission messages across different experimental conditions. Specifically, using desirable language with gain message framing and feasible language with loss message framing can lead to stronger willingness to support boosting policies of tourism carbon reduction (Study 1). The results further show that the congruity effect is mediated by hope and worry (Study 2) and is weakened for participants with a high need for cognition (Study 3). These findings also offer actionable practical implications for destination managers to design effective tourism carbon emission communication. Full article

Given the large natural gas (NG) reserves of the Intermountain West (I-WEST) region in the USA, it can emerge as a leader in hydrogen (H₂) production. Currently, H₂ production via steam methane reforming (SMR) of NG releases carbon dioxide (CO₂) and the natural gas infrastructure has fugitive NG and H₂ losses during production, conversion and transportation. Integrated carbon capture and sequestration (CCS) is a promising approach for producing hydrogen and CO₂ from the SMR process for industrial uses including power, chemicals and fuels. However, the NG losses and regional water availability can be limiting factors for H₂ production. H₂ production assessments are often made at the global scale and neglect regional factors such as abundant gas and limited water in the I-WEST. We demonstrate that a regional SMR process unit sitting near NG wells offers opportunities to significantly reduce fugitive NG losses. We show that regional H₂ production by SMR has a lower emissions profile than widespread natural gas combustion in the I-WEST and reduces the H₂ production cost as well. Replacing the I-WEST transportation sector with H₂ fuel cell vehicles and using 100% H₂-powered electricity can provide substantial reductions in water consumption and fuel costs. This is better than blending H₂ with NG which is more expensive. The captured CO₂ can be effectively used for enhanced oil recovery in I-WEST. Finally, the potential of utilizing produced, brackish and treated impaired water sources is assessed to meet the water needs for H₂ production in the I-WEST. Full article

Global urbanization is shifting from incremental expansion to stock optimization, and old residential communities have become important spatial units for low-carbon transition. However, in existing built environments, traditional process-based inventory methods face practical constraints, including missing original drawings, complex site conditions, and severe vegetation obstruction. As a result, systematic accounting of buildings, landscapes, and natural carbon sinks remains difficult. This study integrates life cycle assessment (LCA), BIM reverse modeling, 3D point clouds, DesignBuilder simulation, inventory-based accounting, and i-Tree Eco to construct a life cycle carbon emission accounting framework for old residential communities. The framework links current-condition data reconstruction, quantity take-off, operational energy simulation, landscape inventory accounting, and vegetation carbon sequestration assessment. It is applied to Nanyuan Xincun in Hefei to quantify the community-scale carbon source–sink structure. The results show that Nanyuan Xincun presents a clear operation-led emission pattern, with the operation and maintenance phase accounting for 82.52% of total positive emissions. Within architectural engineering, operation and maintenance accounts for 82.91%, while material production accounts for 13.28%. Landscape engineering shows a more mixed structure, with operation and maintenance accounting for 52.95% and material production accounting for 36.49%. Vegetation carbon sequestration analysis shows that mature trees and shrubs are the main ecological carbon assets. Annual sequestration reaches 16.95 t-CO₂e/a, and trees and shrubs contribute 92.85% of total vegetation carbon storage. Under current vegetation conditions, annual sequestration is equivalent to 32.99% of annual landscape operation emissions, indicating considerable ecological compensation potential. Based on these findings, this study proposes four optimization pathways: operational energy reduction, low-carbon material substitution, construction and demolition waste recycling, and mature tree protection. These pathways provide data support for refined carbon management and low-carbon renewal in existing communities. Full article

Green shipping corridors have become a key strategic initiative for advancing maritime decarbonization. This study develops an AIS-based bottom–up framework for estimating carbon emissions and compliance costs in green shipping corridors. The framework combines corridor fleet identification, AIS-based energy consumption and emission estimation, and compliance-cost modeling under the IMO CII and GFI requirements. On this basis, eight alternative energy options—HFO, fossil LNG, bio-LNG, e-LNG, bio-methanol, e-methanol, green ammonia, and biofuel B100—together with carbon capture technology, are incorporated into the analysis and applied to the Shanghai–Los Angeles/Long Beach green shipping corridor. The results show that before 2035, the emission reduction requirements of CII can cover the basic compliance requirements of GFI. Without carbon capture, the combined use of fossil LNG and bio-LNG appears to be a relatively favorable transition pathway. When carbon capture is considered, LNG with carbon capture and HFO with carbon capture emerge as two relatively advantageous transition pathways. During 2025–2035, it is recommended that ships first adopt fossil LNG, then gradually introduce limited amounts of bio-LNG, and subsequently integrate carbon capture once the technology becomes mature. Full article

Hydrogen enrichment of compression ignition (CI) engines has emerged as a promising strategy to simultaneously enhance thermal efficiency and reduce carbon-based emissions. This study numerically investigates how hydrogen enrichment affects engine performance and emissions in methanol–diesel dual-fuel CI engines, a combustion mode gaining increasing attention for replacing fossil diesel with sustainable fuels, particularly in hard-to-abate sectors such as maritime transport. The simulations are based on the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations, incorporating the RNG k–ε turbulence model, the Eddy Dissipation Concept (EDC) for turbulence–chemistry interaction, and the G-equation for turbulent premixed flame propagation. The numerical model is validated against experimental data for in-cylinder pressure and heat release rate at 45% methanol substitution ratio (by energy). The results indicate that increasing the hydrogen enrichment ratio (HER, defined on an energy basis) from 5% to 20% raises the Sauter mean diameter (SMD) of the diesel fuel from 20.2 µm to 28.0 µm (+38%), driven by reduced aerodynamic breakup intensity associated with modified gas-phase properties under hydrogen enrichment. Furthermore, hydrogen’s elevated adiabatic flame temperature and superior mass diffusivity intensify combustion, raising peak in-cylinder pressure from 75.2 to 79.1 bar (+5.2%), amplifying the peak heat release rate from 129 to 211 J/°CA (+63.6%), and elevating maximum in-cylinder temperature from 1542 to 1735 K (+193 K). Under the investigated CFD operating conditions, these thermodynamic gains translate into an engine-level 6% improvement in indicated thermal efficiency and a 14% reduction in indicated specific fuel consumption (accounting for hydrogen, methanol, and diesel) at HER 20%. On the emissions front, CO₂ declines by 24% in direct proportion to the carbon-containing fuel mass displaced by hydrogen substitution, while NOₓ increases approximately twofold from 0.10 g/kWh at HER 0 to 0.21 g/kWh at HER 20, driven by peak temperature elevation. These findings establish hydrogen-enriched methanol–diesel dual-fuel combustion as a viable pathway toward high-efficiency, low-carbon CI engine operation for heavy-duty transport applications. Full article

Reducing agricultural carbon emissions is an important component of China’s efforts to achieve its carbon peaking and carbon neutrality goals. As an important policy oriented financial instrument, green credit can facilitate lower agricultural carbon intensity by directing resources more efficiently across regions and encouraging low carbon transformation in agriculture. Using panel data for 30 Chinese provinces from 2005 to 2022, this study measures agricultural carbon emission intensity (ACEI) from six sources. It then examines the spatial spillover effects, transmission channels, and nonlinear characteristics associated with green credit by using a spatial Durbin framework, mediation analysis, and panel threshold model. The results indicate that: (1) green credit development is significantly associated with lower ACEI; (2) green credit exhibits significant spatial spillover effect, being associated with lower ACEI both within a province and in neighboring provinces; (3) green credit exhibits marked regional heterogeneity in its impact on ACEI: it shows both direct and spillover effects in the eastern region, only spillover effects in the central region, and only direct effects without effective diffusion in the western region; (4) green credit is associated with lower ACEI through industrial structure upgrading and lowering agricultural energy consumption intensity; (5) green credit has a single threshold effect on ACEI based on its own development level. After crossing the threshold, the emission intensity reduction effect weakens but remains significant. These results offer empirical evidence for refining green credit arrangements and advancing coordinated agricultural emission reduction across regions. Full article

This research evaluated levels of peanut meal inclusion in diets for laying hens. A total of 200 Hisex White hens, 72 weeks of age, were used in a completely randomized design with five treatments and ten replicates of four hens each. Treatments consisted of replacing soybean meal with peanut meal at 0, 25, 50, 75, and 100%. Over a 70-day period, feed intake, egg production, egg weight, egg mass, feed conversion, and internal and external egg quality were evaluated. Economic analyses of diets and estimates of the carbon footprint were also conducted based on life cycle assessment data of the ingredients. Total replacement of soybean meal with peanut meal did not significantly affect productive performance or egg quality (p > 0.05). Increasing levels of peanut meal inclusion linearly reduced feed cost, providing savings of up to US$ 41.81 per ton. In addition, a progressive reduction in the carbon footprint of the diets was observed, reaching a decrease of 26.37% in CO₂ equivalent emissions. Peanut meal can fully replace soybean meal in laying hen diets without compromising productive performance or egg quality while reducing feed costs and environmental impact. Full article

The rapid expansion of subway systems has led to significant carbon emissions during station construction, yet a systematic and interpretable framework for evaluating low-carbon performance across different construction methods remains underdeveloped. To address this gap, this study proposes a comprehensive evaluation model that integrates a pressure–state–response (PSR) framework with an entropy-weighted TOPSIS method. A multi-dimensional indicator system comprising 17 indicators was established, covering material and energy consumption (pressure), environmental carbon states (state), and management responses (response). The entropy weight method was employed to determine objective indicator weights, and the TOPSIS method was used to rank the overall low-carbon performance of different construction schemes. An empirical study of a subway station in Guangzhou, China, was conducted to compare three construction methods: open-cut, top-down cover excavation, and reverse cover excavation. The results demonstrate that the reverse cover excavation method achieves the highest low-carbon performance. Electricity consumption and concrete-related emissions were identified as the most influential factors, while obstacle analysis revealed key constraints for carbon reduction. The proposed PSR–entropy–TOPSIS framework offers a transparent, data-driven decision-support tool for optimizing construction schemes, contributing to the sustainable development goals of urban rail transit projects. Full article

Against the global carbon neutrality backdrop, amine-based CO₂ capture technology is critical for industrial greenhouse gas emission reduction. However, mixed amine absorbents can cause severe corrosion of Q235B carbon steel, restricting the stable operation of carbon capture, utilization, and storage (CCUS) projects. This study systematically investigated the corrosion behavior of Q235B carbon steel in a novel mixed amine system under simulated industrial conditions using weight loss tests, electrochemical measurements (EIS, potentiodynamic polarization), and advanced characterizations (FT-IR, ¹³C NMR, SEM-EDS, XRD). The temperature was the dominant factor: corrosion rate increased significantly with rising temperature. Under CO₂-saturated conditions, 15–30% absorbent concentrations showed no significant effect on corrosion rate owing to similar molar loading and pH. At 60 °C and 30% concentration, the corrosion rate peaked at 30 L/L CO₂ loading. Carbamate accumulation promoted corrosion at low loading, while increased bicarbonate inhibited corrosion at high loading. The main corrosion products (Fe₃O₄, Fe₂O₃) formed loose, porous films with poor protectiveness. This work clarifies the electrochemical corrosion mechanism and provides data support for corrosion prevention in CCUS equipment. Full article

Environmental implications of resource dependence remain a central concern for hydrocarbon-based economies undergoing energy transition. Using panel data for GCC countries over 1990–2024 and second-generation econometric techniques that account for cross-sectional dependence and heterogeneity, this study identifies a stable long-run relationship between natural resource rents, renewable energy, and CO₂ emissions. The results show that a 1% increase in natural resource rents is linked to a 0.21% rise in CO₂ emissions, highlighting the persistence of carbon-intensive economic structures. By contrast, renewable energy is associated with a 0.15% reduction in emissions, although its environmental contribution remains modest. The interaction effect is negative (−0.048) but only partially robust, indicating that renewable energy weakens, but does not fully offset, the environmental pressure associated with resource dependence. These findings suggest that energy transition in GCC economies remains gradual and structurally constrained, requiring not only renewable expansion but also deeper transformation of hydrocarbon-based growth models. Full article

Against the backdrop of global climate warming and energy shortages, China proposed the” dual-carbon strategy” in 2020 to address climate change and promote ecological civilization. As a high-carbon emission industry, the iron and steel sector faces an urgent need to accelerate low-carbon transformation. In 2024, China’s crude steel production accounted for over 50% of the total global crude steel production, with the blast furnace–basic oxygen furnace route remaining the dominant process. As a natural iron-bearing raw material, lump ore features high iron grade and low cost, eliminating the requirements of high-temperature processing steps such as sintering or pelletizing. Therefore, increasing the proportion of lump ore in the blast furnace burden represents an effective approach to achieving energy conservation and emission reduction. However, constrained by technical constraints, the current utilization rate of natural lump ore in Chinese steel enterprises remains generally low. Research indicates that despite their higher iron content, lump ores exhibit deficiencies in metallurgical properties such as thermal shock resistance and softening–melting drip characteristics, limiting their large-scale application. Therefore, it is typically necessary to perform pre-treatment such as preheating before charging into the furnace. In actual blast furnace burden design, it is essential to balance metallurgical performance and economic considerations by appropriately combining lump ore with high-basicity sinter and pellets. This approach leverages high-temperature interactions among the burden materials to optimize the overall softening and melting behavior of the mixed charge, thereby ensuring smooth furnace operation while simultaneously advancing the low-carbon transition of the iron and steel industry. Full article

Prosumer communities, aggregations of residential and commercial entities equipped with distributed energy resources (DER), including photovoltaic systems, battery storage, and flexible loads, are emerging as critical organizational units in decarbonising smart grid architectures. Managing these communities effectively requires balancing economic efficiency with equity, autonomy, and environmental sustainability, objectives that conventional centralized control methods and existing multi-agent reinforcement learning (MARL) implementations fail to address simultaneously. This article proposes a value-aligned hierarchical multi-agent reinforcement learning (VA-HMARL) framework as a formally unified architecture that embeds equity (Jain’s Fairness Index J ≥ 0.90), individual autonomy, and carbon sustainability as hard constraints within the MARL reward structure. The framework integrates: a multi-objective Value Alignment Module (VAM) combining economic, fairness, sustainability, and comfort objectives; attention-based implicit coordination for scalable agent interaction; and differentially private federated policy aggregation (ε = 1.0, δ = 10⁻⁵) for GDPR-compliant collaborative learning. Simulation on a 20-prosumer community modelled on the IEEE 33-bus feeder over 10 Monte Carlo runs (300 episodes each) demonstrates: a 6.2% energy cost reduction versus the Rule-Based baseline (p = 0.0004); a Jain’s Fairness Index of 0.912 ± 0.031 at policy convergence (final 50 episodes), satisfying the J ≥ 0.90 community equity floor; and an 18.0% reduction in CO₂ emissions. The economic efficiency trade-off relative to performance-optimized MARL baselines is limited to 2.4%, within the 5% design target. These results establish VA-HMARL as a technically feasible and ethically grounded paradigm for autonomous decentralized energy governance. Full article

Despite the rapid expansion of photovoltaic (PV) installations over the past decade, challenges such as curtailments of renewable energy sources (RESs) and grid constraints continue to limit the capacity of Cyprus’ power system to accommodate higher solar penetration. In this context, grid reliability, defined as the ability to maintain stable operation by balancing supply and demand, minimizing curtailment, and reducing stress on the island network, has emerged as a critical concern. The deployment of PV-plus-storage systems offers a viable solution to enhance grid reliability while alleviating operational constraints. This paper presents a real-world case study of the first commercially deployed grid-connected PV-powered, battery-integrated electric vehicle (EV) charging station in Cyprus. Commissioned in May 2025, the system integrates a 60.32 kW_p rooftop PV array, a 100 kW/97 kWh battery energy storage system (BESS), and a 160 kW DC fast charger. A custom cloud-based energy management platform enables real-time monitoring, forecasting, and optimization under a zero-export scheme. High-resolution operational and weather data were collected between 15 May and 30 November 2025. Over this period, the integrated PV-battery system supplied 29% of the site’s total energy demand (self-sufficiency rate of 28.97%) and achieved a self-consumption rate of 98.69%. Such rates would not have been attainable with a pure PV system, given the depot’s evening-concentrated EV charging demand profile, which requires the BESS to time-shift daytime solar generation. The system reduced depot electricity costs by approximately 29%, generating €16,010 in savings and avoiding 26.47 tonnes of carbon dioxide (CO₂) emissions compared to a grid-only baseline. Beyond site-level performance, the system contributed to grid stress reduction by absorbing excess PV generation that would otherwise have been curtailed/wasted. Operational insights indicate minimal temperature-related issues, highlight the importance of automated fault detection and alerting to minimize downtime, and demonstrate how periodic operation strategies can optimize system performance and mitigate curtailment in Cyprus’s isolated grid. Full article