Search Results (962)

The article presents issues related to fossil fuel energy consumption and CO₂ emissions from motor vehicles. It identifies the main areas of research in this field in the context of motor vehicles, namely driver behavior, fuel consumption, and OBD systems. The research sample consisted of experimental data containing records of a series of test drives conducted with a passenger vehicle equipped with a gasoline-powered internal combustion engine, collected via an OBD diagnostic interface. Three subsets related to engine operation and energy demand patterns were distinguished for the study: during vehicle start-up and low-speed driving (vehicle start-up mode), during urban driving, and during extra-urban driving. Multiple regression models were constructed for the analyzed subsets to predict CO₂ emissions based on engine energy output parameters (power, load) and vehicle kinematic parameters. The developed models were subjected to detailed evaluation and mutual comparison, taking into account their predictive performance and the interpretability of the results. The analysis made it possible to identify the variables with the most substantial impact on CO₂ emissions and fuel energy consumption. The models allow individual drivers to monitor and optimize vehicle energy efficiency in real-time. The extra-urban driving model achieved the highest predictive accuracy, with a mean absolute error (MAE) of 19.62 g/km, which makes it suitable for real-time emission monitoring during highway driving. Full article

Coal gangue, as a predominant solid byproduct of the global coal industry, poses severe environmental challenges because of its massive accumulation and low utilization rate. This review systematically synthesizes and analyzes published experimental and analytical studies on the dual-pathway utilization of coal gangue in concrete, including Pathway 1 (aggregate substitution) and Pathway 2 (cementitious activity activation). While the application of coal gangue aggregates is traditionally limited by their inherent high porosity and lower mechanical strength than those of natural aggregates, this review demonstrates that performance barriers can be effectively overcome. Through multiscale modification strategies—including surface densification, biological mineralization (MICP), and matrix synergy—the interfacial defects are significantly mitigated, allowing for feasible substitution in structural concrete. Conversely, for the mineral admixture pathway, controlled thermal activation is identified as a key process to optimize the phase transformation of kaolinite, thereby significantly enhancing pozzolanic reactivity and long-term durability. According to reported studies, the partial replacement of natural aggregates or cement with coal gangue can reduce CO₂ emissions by approximately tens to several hundreds of kilograms per ton of coal gangue utilized, depending on the substitution level and activation strategy, highlighting its considerable potential for carbon reduction in the construction sector. Nevertheless, challenges related to energy-intensive activation processes and variability in raw gangue composition remain. These limitations indicate the need for future research focusing on low-carbon activation technologies, standardized classification of coal gangue resources, and long-term performance validation under realistic service environments. Based on the synthesized literature, this review discusses hierarchical utilization concepts and low-carbon activation approaches as promising directions for promoting the sustainable transformation of coal gangue from an environmental liability into a carbon-reduction asset in the construction industry. Full article

Understanding how transport conditions and the built environment shape urban CO₂ emissions is critical for low-carbon urban development. This study analyses CO₂ emission intensity across fifty major Chinese cities using integrated ODIAC emissions, VIIRS night-time lights, traffic performance indicators, built-environment morphology, population/POI structure, and socioeconomic controls. We develop a GeoAI workflow that couples XGBoost modelling with SHAP interpretation, congestion-based city grouping, and 1 km grid-level GNNWR to map intra-urban spatial non-stationarity. The global model identifies night-time light intensity as the strongest predictor, followed by population density and building density. SHAP results reveal pronounced nonlinearities, with high sensitivity at low–medium levels and diminishing marginal effects as activity and density increase. Although transport indicators are less influential in the aggregate model, their roles differ across congestion regimes: in low-congestion cities, emissions align more consistently with overall activity intensity, whereas in high-congestion cities they respond more strongly to population distribution, motorisation, and built-form intensity, with less stable relationships. Grid-level GNNWR further shows that key mechanisms are spatially uneven within cities, with local effects concentrating in specific cores and corridors or fragmenting across multiple subareas. These findings demonstrate that emission drivers are context-dependent across and within cities. Accordingly, uncongested cities may gain more from activity-related energy-efficiency measures, while highly congested cities may require congestion-sensitive land-use planning, spatial-structure optimisation, and motorisation control. Integrating explainable GeoAI with regime differentiation and spatial heterogeneity mapping provides actionable evidence for targeted low-carbon planning. Full article

This study examines the relationship between energy consumption and energy-related CO₂ emissions for a sample of 79 reporting entities, grouped into seven regions, over the period 2013–2023. The methodology uses three empirical tools: (i) Tapio elasticity to classify types of decoupling; (ii) Kaya–LMDI decomposition to identify factors that determine emissions; and (iii) a log-difference panel model to separate year- and country-specific effects. The results indicate a reduction in carbon intensity in all regions, more pronounced in Europe and North America. According to the Tapio classification, Europe is in recessive decoupling, the Middle East is on the verge of expansive decoupling, North and South America are in strong expansive decoupling, and Asia Pacific, Africa, and CIS show only weak signals of expansive decoupling. The LMDI results show that, in regions with strong decoupling, the decrease in carbon intensity contributes to reducing emissions. In those with weak decoupling, the effects are partially canceled out by population growth and energy demand. Finally, the fixed-effects panel model does not identify any structural decoupling at the regional level. Overall, this study contributes to the literature by separating long-term structural effects from annual fluctuations. On this basis, we provide clear guidelines for designing regional energy policies. Full article

This study aims to identify and interpret latent energy-economic typologies across European economies and to assess whether their energy transition paths exhibit convergence or persistent structural divergence. To achieve this objective, the paper investigates the energy–economic structure of thirteen European economies between 2000 and 2024 using an integrated fuzzy–machine learning framework. Eight indicators related to renewable energy, energy efficiency, emissions, electricity use, digitalization, investment, urbanization and economic development were analyzed to identify structural typologies across countries. Using the Fuzzy C-Means algorithm, four distinct clusters were identified: (i) moderately developed economies with balanced renewable adoption and energy efficiency, (ii) structurally integrated economies with medium energy intensity and stable economic performance, (iii) an emerging economy with persistent structural constraints, and (iv) advanced high-performance economies engaged in accelerated energy transition. To validate the fuzzy classification, Random Forest and XGBoost models were trained based on the same indicators, achieving high predictive accuracy (94% and 92%, respectively). Feature importance analysis reveals that CO₂ emissions, energy efficiency and urbanization play the most significant roles in differentiating country profiles. The proposed framework provides a comprehensive approach for understanding energy transition heterogeneity, structural convergence and the drivers shaping the evolution of European energy–economic systems. Full article

This study investigates the energy performance and preliminary turbomachinery design of post-combustion CO₂ compression systems integrated into an ultra-supercritical coal-fired power plant with carbon capture and storage (CCS). To enable pipeline transport, CO₂ must be delivered at 150 bar and 15 °C, i.e., in liquid phase. Unlike conventional configurations that compress CO₂ entirely in the gaseous/supercritical phase before final cooling, two alternative layouts are proposed, introducing an intermediate liquefaction step prior to liquid-phase compression. Each layout uses a chiller system that operates at CO₂ condensation temperatures of 10 °C and 20 °C. The energy performance and the system layout architecture are evaluated and compared with the conventional gaseous-phase compression configuration. An in-depth sensitivity analysis, which varies the flow coefficient, the working coefficient, and the degree of reaction, confirms that the turbomachinery preliminary design, based on input parameters related to the specific speed, is a high-efficiency design. The results indicate that the 10 °C liquefaction layout requires the least compression power (60 MW), followed by the 20 °C layout (62.5 MW) and the conventional system (67 MW). Including the consumption of the chiller, the proposed systems require an additional power of 11–12 MW, compared to just over 1 MW for the conventional layout with simple CO₂ cooling. These results highlight the significant influence of the integration of the chiller on the overall power requirement of the system. Although the proposed configurations result in a larger equipment footprint, the integrated capture and compression/liquefaction system allows for very low CO₂ emissions, making the power plant more sustainable. Full article

Environmental health concerns remain a major global challenge. In many nations, the adoption of measures to mitigate the negative environmental impacts of construction-related activities has been slow. Prior research has clarified that further study/advancement are required to improve environmental health/sustainability (EHS). To determine the focus of previous studies, this study attempts to identify, analyse, and visualise the trends in research concerning EHS in construction-related domains. The data were obtained from the Scopus database, and the study employed a bibliometric approach. The following keywords were used to search the database: ‘environmental health’ OR ‘ecological health’ OR ‘environmental sustainability’ OR ‘ecological sustainability’ OR ‘Environmental safety’ OR ‘ecological safety’ AND ‘construction industry’ OR ‘building industry’ to retrieve relevant documents. The analysis included co-citation analysis, keyword co-occurrence and trend mapping. The findings revealed four themes: Environmental Sustainability and Energy-Oriented Decision-Making, Low-Carbon Cementitious Materials and Mechanical Performance of Concrete, Waste Management and Circular Economy Practices, and Life Cycle Assessment and Carbon Emission Analysis. The keyword findings revealed very scant research in environmental health unlike environmental sustainability. Spain, China, and Saudi Arabia are the top three in terms of citation-to-publication ratio, indicating strong influence in literature sources. However, India has the highest number of publications. The findings also suggest that more relevant studies are required in African nations and South Asian countries. It further highlighted a knowledge gap that emerging economies must address to enhance the sustainability and environmental performance of construction projects. This bibliometric analysis is unique in its integrated examination of environmental sustainability and environmental health in the construction industry, employing strategic thematic mapping to reveal system-level linkages, contextual gaps, and targeted directions for future research. The conclusions provide scholars and stakeholders in the built environment with a solid theoretical basis, enhancing the industry’s preparedness to mitigate the adverse environmental and climatic impacts of traditional construction methods. Full article

This study presents an integrated Life Cycle Sustainability Assessment (LCSA) of the Natural gas-to-methanol (NGTM) and methanol-to-gasoline (MTG) pathways using Aspen HYSYS process modeling, Environmental Life Cycle Assessment (LCA), Social Life Cycle Assessment (SLCA), and Life Cycle Costing (LCC). The results reveal significant variability in sustainability performance across process units. The DME and MTG Reactors Section generates the highest direct greenhouse gas (GHG) emissions at 0.86 million tons CO₂-eq, representing 54.9% of total global warming potential, while the Compression Section consumes 2717.5 TJ/year of energy, making it the dominant source of electricity-related indirect emissions. Distillation and Purification withdraws 31,100 Mm³/year of water—approximately 99% of total demand—yet delivers 86.6% of the overall economic surplus despite high operating costs. Social impacts concentrate in the Methanol Reactor Looping and DME and MTG Reactors Sections, with human health burdens of 305.79 and 804.22 DALYs, respectively, due to catalyst handling and high-pressure operations. Sensitivity results show that methanol purity rises from 0.9993 to 0.9994 with increasing methane content, while gasoline output decreases from 3780 to 3520 kg/h as natural gas flow increases. The findings provide process-level evidence to support sustainable development of natural gas-based fuel conversion industries, aligning with Qatar National Vision 2030 objectives for industrial diversification and lower-carbon energy systems. Full article

The Paris Agreement and related international climate frameworks aim to reduce global carbon intensity; however, carbon dioxide emissions from electricity generation remain high, motivating the development of coal–renewable coupling technologies to lower the carbon intensity of power production. Coal–renewable coupling refers to the technical integration of conventional coal-fired power systems with renewable energy sources such as wind and solar to form a synergistic and complementary energy supply system. At present, systematic reviews and comprehensive analyses of coal–renewable coupling technologies are still limited. Accordingly, this paper categorizes existing approaches into two pathways—deep flexible load regulation and co-firing-based emission reduction—and systematically reviews the current state of technological development, identifies key challenges, and discusses potential future directions. Deep flexible load regulation includes flexibility retrofitting of coal-fired units and the integration of energy storage modules, whereas co-firing-based emission reduction mainly involves the co-combustion of coal with zero-carbon fuels. The analysis focuses on large-scale coal-fired units, covering low-load stable combustion technologies, steam turbine retrofitting, and rapid start-up and shut-down strategies. For energy storage-assisted load regulation, both conventional options and emerging technologies such as molten salt and high-temperature solid particle thermal energy storage are examined. Zero-carbon fuels considered include biomass, ammonia, and hydrogen. Furthermore, the economic feasibility of the various technologies is evaluated, providing reference value for deep flexibility retrofitting and substantial emission reduction in large-scale coal-fired power plants. Full article

Carbon Capture, Utilization and Storage (CCUS) is a critical area of research due to its potential to significantly reduce CO₂ emissions from industrial processes and fossil fuel-based power generation. Aqueous amine solutions are commonly used as chemical solvents for CO₂ capture. However, their application is disfavoured by the high energy requirements and related operational costs, toxicity, and corrosion issues. To address these limitations, research is in general focused on developing novel solvents that can overcome the drawbacks of traditional amines. This development needs the study of phase equilibria in systems for which detailed physicochemical data are often scarce in the literature. In particular, understanding the solubility of gases (CO₂) in possible solvent mixtures is essential for evaluating their suitability for chemical or physical absorption processes. In this work, a dedicated setup was installed to generate the experimental data for these novel systems. This unit was designed to measure the solubility and diffusivity of gases in low-volatility liquids that could be alternative CO₂ solvents. A detailed experimental procedure was established, and the unit was initially validated by measuring CO₂ solubility in a 30 wt% monoethanolamine (MEA) solution, one of the most widely used industrial solvents. The experiments were conducted under conditions representing both the absorption and the regeneration sections of a CO₂ removal plant. The resulting equilibrium data were analyzed by employing several thermodynamic models, and the model providing the best representation was selected. Full article

Against the backdrop of continuously expanding global magnesium alloy applications and surging scrap generation, achieving efficient recycling and low-carbon regeneration of magnesium alloys has emerged as a key pathway for advancing green transformation in manufacturing. The AM50A recycled magnesium alloy was selected as the research subject, employing the attributional life cycle assessment (ALCA) methodology to systematically calculate its “cradle”-to-“gate” carbon footprint across three stages: raw material acquisition, transportation, and production. The results indicate that the carbon footprint of AM50A recycled magnesium alloy is 4.9399 kg CO₂e/kg, with the production stage accounting for a significant 99.34% of emissions, identified as the primary source. The combined contribution from raw material acquisition and transportation stages is only 0.66%. Compared to magnesium alloys produced by the Pidgeon process, greenhouse gas (GHG) emissions can be reduced by approximately 67.56% through the recycling process, highlighting its significant advantages in promoting low-carbon manufacturing and circular economic development for magnesium alloys. This study provides data support for the environmental performance assessment of recycled magnesium alloys and offers a scientific basis for optimizing energy conservation and emission reduction pathways in related industries. Full article

Global carbon emissions are driving the maritime industry toward cleaner fuels, with LNG already established as a transitional option that reduces SOx, NOx, and particulate emissions relative to conventional marine fuels and in line with decarbonisation strategies. This research aimed to explore the transition of offshore and marine platforms from conventional marine fuels to cleaner alternatives, with liquefied natural gas (LNG) emerging as the principal transitional fuel. Subsequently, floating liquefied natural gas (FLNG) platforms are increasingly being deployed to harness offshore gas resources, yet they face critical challenges related to weight, space, and energy efficiency. The study proposes pathways for transitioning FLNG energy systems from LNG to zero-carbon fuels, such as hydrogen derived directly from LNG resources, to optimise fuel supply under the unique operational constraints of FLNG units. The work unifies the independent domains of pure-fuel and blending-fuel processes for LNG and hydrogen, viewed in the context of thermodynamic processes, to optimise hydrogen–LNG co-firing gas turbine performance and meet the base power line of 50 MW. Furthermore, the research article will contribute to the development of other floating production platforms, such as FPSOs and FSRUs. It will be committed to clean energy policies that mandate support for green alternatives to hydrocarbon fuels. Full article

Aiming at the economic optimization problem in the coupling application of intermittent renewable energy and electrolytic hydrogen production equipment, this paper proposes a dual-mode dynamic switching mechanism. This mechanism breaks through the limitations of the fixed operation mode and realizes intelligent switching between the two modes of hydrogen energy driven power dispatching (HDPD) and power-driven hydrogen production (PDHP) through a decision index and adaptive threshold that integrates multiple factors. The simulation results show that the proposed method achieves a total cost which is 10.6% and 16.3% lower than that of PDHP and HDPD modes, respectively. The levelized cost of hydrogen is optimized to 0.25 USD/kg, which is 34.2% lower than that of HDPD mode. Moreover, the proposed method increases hydrogen production by 14.4% compared to PDHP mode. The system maintains a high renewable energy utilization rate of 96.34% and achieves carbon emission reduction of 3.25 million kg CO₂. The counterfactual test verifies the effectiveness of the switching mechanism and quantifies the opportunity cost related to decision-making. This study provides key decision-making tools and methodological references for the deployment of efficient, flexible, and economically sustainable green hydrogen energy systems. Full article

Producing methanol through carbon capture and utilization presents a sustainable alternative to traditional methods. This study explores two main production pathways, which are further divided into four distinct scenarios. In Nova Scotia, methanol could be produced by combining green hydrogen with either biogenic or fossil-derived carbon dioxide sources. The four scenarios differ in scale, carbon source, and methanol output. Scenario 1, a small biomass plant, captures 0.033 Mt CO₂/yr and produces 0.024 Mt methanol, but uses only 3% of the green hydrogen. Scenario 2, a natural gas plant, captures 0.90 Mt CO₂/yr and produces 0.66 Mt methanol with 69% hydrogen use. Scenario 3, a coal plant, captures 2.30 Mt CO₂/yr, converting 57% to 0.94 Mt methanol. Scenario 4, a proposed BECCS plant, captures 2.46 Mt CO₂/yr, converts 53% to 0.94 Mt green methanol, and delivers the highest net-negative emissions, making it the most climate-friendly option. While Scenarios 1, 2, and 3 could benefit from retrofitting existing plants, Scenario 4 would require significant infrastructure investment to make it a reality. The study concludes that while Nova Scotia possesses the resources to support renewable and non-renewable methanol production, challenges related to CO₂ availability, green hydrogen production, biomass supply, energy requirement, and public perception must be addressed. Full article

Care homes are an energy-intensive component of the health and social care sector, with high demands on heating, lighting, laundry, catering and medical technologies. This constant energy use makes care homes a notable contributor to global greenhouse gas emissions. Decarbonising care homes presents an opportunity to reduce emissions, operational costs, and deliver health co-benefits by improving air quality and thermal comfort. This scoping review mapped the international evidence on decarbonisation in care homes to inform sustainable practice and policy development. Guided by Joanna Briggs Institute methodology, seven databases (CINAHL, EMBASE, IEEE, MEDLINE, PubMed, Scopus, and Web of Science) were searched. Eligible studies included care home facilities, residents or staff with data managed in Covidence and extracted using the “The Greenhouse Gas Protocol Corporate Standard Inventory Accounting”. A total of 22 studies met the inclusion criteria. The evidence was concentrated around Scope 2 emissions, through efforts to monitor and reduce electricity use, while Scope 1 (facility emissions) and Scope 3 (supply chain emissions) remain comparatively underexplored. Evidence was fragmented and revealed risk aversion and care quality concerns related to adopting low-carbon technologies, as well as a growing interest in digital technologies and sustainable food procurement. Care homes should be prioritised within net zero healthcare frameworks, with targeted research, policy guidance, and investment to support decarbonisation. Full article