Search Results (8,400)

The catalytic hydrogenation of carbon dioxide (CO₂) represents a transformative approach for reducing greenhouse gas emissions while producing sustainable fuels and chemicals, with ethanol being particularly promising due to its compatibility with existing energy infrastructure. Despite significant progress in converting CO₂ to C₁ products (e.g., methane, methanol), selective synthesis of C₂₊ compounds like ethanol remains challenging because of competing reaction pathways and byproduct formation. Recent advances in thermo-catalytic CO₂ hydrogenation have explored diverse catalyst systems including noble metals (Rh, Pd, Au, Ir, Pt) and non-noble metals (Co, Cu, Fe), supported on zeolites, metal oxides, perovskites, silica, metal–organic frameworks, and carbon-based materials. These studies reveal that catalytic performance hinges on the synergistic effects of multimetallic sites, tailored support properties and controlled reaction micro-environments to optimize CO₂ activation, controlled hydrogenation and C−C coupling. Mechanistic insights highlight the critical balance between CO₂ reduction steps and selective C−C bond formation, supported by thermodynamic analysis, advanced characterization techniques and theoretical calculations. However, challenges persist, such as low ethanol yields and undesired byproducts, necessitating innovative catalyst designs and optimized reactor configurations. Future efforts must integrate computational modeling, in situ/operando studies, and renewable hydrogen sources to advance scalable and economically viable processes. This review consolidates key findings, proposes potential reaction mechanisms, and outlines strategies for designing high-efficiency catalysts, ultimately providing reference for industrial application of CO₂-to-ethanol technologies. Full article

Biochar is widely used in composting to reduce nitrogen loss; however, the application of acid-modified and alkali-modified biochar in composting remains insufficient. We hypothesize that acid-modified maize straw biochar can simultaneously reduce NH₃ and N₂O losses during the composting process. To test this, a composting experiment was conducted with four treatments: a control with pig manure and corn straw only (CK), adding 5% corn straw biochar (BC), adding 5% HNO₃-modified corn straw biochar (BCN), and adding 5% NaOH-modified corn straw biochar (BCNa). The results showed that, compared to CK, NH₃ emissions were not decreased by BC, but significantly reduced (p < 0.05) by 32.6% in BCN and 36.8% in BCNa, respectively. N₂O was significantly decreased (p < 0.05) by 27.6% in BC and 30.9% in BCNa, respectively. However, BCN significantly increased N₂O emission (p < 0.05) by 368.7%, compared to CK. Compared to CK, the global warming potential (GWP) in the BCNa treatment was significantly reduced by 35.2% (p < 0.05), while the GWP in BCN was significantly decreased by 10.3%. Overall, although BCN treatment may increase N₂O emissions, it can still reduce the GWP. In comparison, BCNa treatment achieves the most significant reduction in GWP during pig manure composting. Full article

Soil amendments are widely applied to improve soil fertility and structure, yet their performance in cold regions is constrained by low accumulated temperatures, frequent freeze–thaw (FT) cycles, and permafrost sensitivity. In this review, ‘cold regions’ refers to high-latitude and high-altitude areas characterized by long winters and seasonally frozen soils and/or permafrost. We screened the peer-reviewed literature using keyword-based searches supplemented by backward/forward citation tracking; studies were included when they assessed amendment treatments in cold region soils and reported measurable changes in physical, chemical, biological, or environmental indicators. Across organic, inorganic, biological, synthetic, and composite amendments, the most consistent benefits are improved aggregation and nutrient retention, stronger pH buffering, and the reduced mobility of potentially toxic elements. However, effectiveness is often site-specific and may be short-lived, and unintended risks—including greenhouse gas emissions, contaminant accumulation, and thermal disturbances—can offset gains. Cold-specific constraints are dominated by limited thermal regimes, FT disturbance, and the trade-off between surface warming for production and permafrost protection. We therefore propose integrated countermeasures: prescription-based amendment portfolios tailored to soils and seasons; the prioritization and screening of local resources; coupling with engineering and land surface strategies; a minimal cold region MRV loop; and the explicit balancing of agronomic benefits with environmental safeguards. These insights provide actionable pathways for sustainable agriculture and ecological restoration in cold regions under climate change. Full article

Smart agricultural systems need stable thermal environments for greenhouses, livestock housing, and on-farm processing. However, renewable heat sources such as solar collectors and heat pumps often cause fluctuations that challenge reliable operation. Thermal energy storage (TES)—particularly water-based sensible tanks, stratified reservoirs, and phase-change material (PCM) systems—provides an effective solution by decoupling heat supply and demand. In this review, tank-based TES technologies for agricultural applications, focusing on design, integration with renewable energy systems, and control strategies, are critically examined. Key performance aspects, including thermal stratification, state-of-charge estimation, and advanced predictive control, are analyzed to identify best practices and limitations. The review finds that sensible TES remains dominant in farm applications due to its low cost and durability, while latent (PCM/ice) and thermochemical storage provide a higher energy density and long-duration potential but are presently limited by material stability, system complexity, and cost. From an environmental perspective, TES contributes to reducing fossil fuel dependence, improving resource efficiency, lowering greenhouse gas emissions, and boosting the resilience of rural farming systems. Overall, TES is recognized as a key enabling technology for climate-smart, energy-efficient, and sustainable agricultural operations. However, remaining research gaps include long-term field validation, standardized performance metrics, and life-cycle environmental assessment. Full article

Community-based collection of household plastic waste (HPW) is expanding in Japan as a way to produce high-value post-consumer recycled (PCR) materials. These systems set up collection points where residents bring recyclable items and sort them into designated bins. However, the environmental impacts of such systems and their advantages over municipal collection remain insufficiently understood, and discussion on the burden placed on residents is limited. This study empirically analyses HPW collection and recycling in community-based systems and examines approaches to producing high-value PCR from environmental and resident-burden perspectives. Environmental impact assessments were conducted for municipal and community-based collection. The time required for residents to wash items before segregation was also evaluated as a burden using questionnaire surveys. A scenario for collecting and recycling five HPW types in Kobe City, Japan, was developed, and environmental impacts and resident burdens were quantified. Results show that community-based collection achieves 3.75 kg-CO_2eq of avoided annual greenhouse gas emissions per household compared with incineration but requires 1.72 h of annual washing time. High-value PCR production depends on resident cooperation during segregation. Clear communication is essential to achieve environmental and economic benefits while minimising additional burdens on residents. Full article

Digital twins, understood as computational replicas of poultry production systems updated in real time by sensor data, are increasingly invoked as transformative tools for precision livestock farming and sustainable agriculture. They are credited with enhancing feed efficiency, reducing greenhouse gas emissions, enabling disease detection earlier and improving animal welfare. Yet close examination of the published evidence reveals that these promises rest on a surprisingly narrow empirical foundation. Across the available literature, no peer reviewed study has quantified the full lifecycle carbon footprint of digital twin infrastructure in poultry production. Only one field validated investigation reports a measurable improvement in feed conversion ratio attributable to digital optimization, and that study’s design constrains its general applicability. A standardized performance assessment framework specific to poultry has not been established. Quantitative evaluations of reliability are scarce, limited to a small number of studies reporting data loss, sensor degradation and cloud system downtime, and no work has documented abandonment timelines or reasons for discontinuation. The result is a pronounced gap between technological aspiration and verified performance. Progress in this domain will depend on small-scale, deeply instrumented deployments capable of generating the longitudinal, multidimensional evidence required to substantiate the environmental and operational benefits attributed to digital twins. Full article

The increasing use of nuclear energy, a reliable baseload power with minimal greenhouse gas emissions, makes managing the heat of dry storage for spent nuclear fuel (SNF) a key engineering issue. Our research indicates that strong heat layers form in standard setups, with over 40% of the vault exceeding 85 °C when airflow stops. A staggered cask setup with outlets on both sides and a 0° inlet yielded the best results, exhibiting the lowest standardized temperature (θave = 0.23) and maintaining wall temperatures below 65 °C. Input speed (4.0–6.0 m/s) is the most significant factor, dropping output temperature from 80 °C to 38 °C. While convection is the primary method of heat transfer (over 90%), radiation becomes significant in low-flow areas, although its effect diminishes as surface temperatures increase. Pressure loss stays low (about 3.2 Pa), which is suitable for mechanics. To improve the system’s practicality and sustainability, it is advised to use both active and passive cooling and to reuse low-grade heat. This work provides reliable guidance for HVAC design under full-load conditions, enhancing the safety, energy efficiency, and cost-effectiveness of SNF storage. Full article

Horticultural facilities can boost crop yields and quality. However, their structures, costs, and resource efficiency vary significantly. Many facility operators prioritize short-term economic gains at the expense of long-term investments in energy efficiency and environmental management, ultimately leading to increased energy consumption and higher greenhouse gas emissions. A systems-based assessment of tomato production is essential for optimizing resource use. This study integrated emergy analysis (EMA) and life cycle assessment (LCA) to evaluate the sustainability of three tomato production systems: polytunnels, solar greenhouses, and glass greenhouses. The Results demonstrated that polytunnels exhibited the best environmental performance, with the lowest environmental loading ratio (ELR, 19.06) and environmental final index (EFI, 1.62). Solar greenhouses showed the best environmental composite index (ECI), outperforming others in mitigating potential environmental impacts. Glass greenhouses imposed the greatest environmental pressure (ELR, 168.51), primarily due to substantial natural gas consumption and infrastructure investment. Scenario analyses revealed that environmental performance across all systems could be significantly enhanced through shortening transport distance, extending the service life of construction materials, and managing energy use. The maximum reduction potentials for the environmental composite index (ECI)were 23.80% for polytunnels, 18.60% for solar greenhouses, and 19.90% for glass greenhouses. This study confirms that polytunnels are the most environmentally friendly option, and targeted management strategies can effectively steer facility-based agriculture toward a more sustainable trajectory. Full article

The building sector accounts for a large percentage of global greenhouse gas emissions, largely from the embodied carbon in common building materials like concrete and steel. Embodied carbon (EC) refers to the greenhouse gases released during the manufacturing, transportation, installation, maintenance, and disposal of building materials. Although growing in popularity, mass timber is still not nearly as common as other building materials. During the early building design stages, engineers often do not have the time or resources to holistically optimize material selection; consequently, concrete and steel remain the materials of choice. This research focused on the development of a fully automated parametric design tool, APDT, to showcase the viability of evaluating and optimizing mass timber in building construction. The APDT was developed using Autodesk’s Revit 2022 and the visual-based programming tool housed within Revit: Dynamo. The automated designer uses parametric inputs of a building, including size, number of stories, and loading, to create a model of a mass timber building with designed glulam columns and beams and cross-laminated timber floor panels. The designer calculates overall material quantities, which are then used to determine the building’s overall embodied carbon impact. Discussed herein is the development of a building design tool that highlights the benefits of optimized mass timber using existing software and databases. The tool allows the designer to expediently provide an estimate of the amount of material and embodied carbon values, thereby making it easier to consider mass timber when determining the structural system at the infancy stage of the project. The methodology outlined herein provides a replicable methodology for creating an APDT that bridges a critical gap in early-stage design, enabling rapid embodied carbon comparisons and fostering consideration of mass timber as a viable low-carbon alternative. Full article

Additive manufacturing (AM), or 3D printing, has a significant, largely beneficial influence on climate change by decreasing material waste and requiring less energy use. The application of AM in the construction and industrial sectors has the potential to reduce carbon emissions. This goal may be accomplished by using material and energy-saving measures, improving manufacturing processes, designing lightweight structures, and reducing transportation operations. While 3DP has the potential to help reduce environmental degradation, it is crucial to recognize the inherent setbacks associated with the technology. Certain AM processes have the potential to emit volatile organic compounds, which contribute to air pollution and hence need improved control. Industrial 3D printers can be excessively expensive, greatly increasing the initial expenditure required to begin a project. Despite these limitations, AM can reduce greenhouse gas emissions, generate better-built environments, and provide a means to reduce energy usage while supporting global carbon neutrality objectives. Governments should extend financial assistance in the form of subsidies to help reduce equipment purchase costs. Furthermore, AM’s capacity to foster a circular economy and minimize overall environmental effects is dependent on the improvement of material recycling and scalability. Full article

Large-scale cultural events generate substantial greenhouse gas emissions, raising increasing concerns regarding carbon neutrality. In Taiwan, long-standing forest conservation policies have largely restricted commercial logging since the early 1990s, resulting in extensive secondary forests where active management options are limited. Within this policy context, improved forest management (IFM) provides a potential pathway to enhance carbon sequestration while maintaining conservation objectives. This study evaluates the feasibility of using afforestation combined with IFM to offset the carbon emissions of the Taipei Biennial 2020, estimated at approximately 390 t CO₂-e. Carbon sequestration was assessed using the Verified Carbon Standard (VCS) methodology (VM0005 v1.2) under the principles of Measurement, Reporting, and Verification (MRV). A total area of 52.70 ha was assessed, with 10.11 ha designated as the project activity area. Over a 25-year period, projected CO₂ sequestration across four baseline scenarios ranged from 3816 to 4523 tons, indicating that event-related emissions could be offset within 8–9 years. Uncertainty remains due to hypothetical management assumptions, highlighting the need for continuous monitoring and adaptive management. Full article

In the face of accelerating climate change and urbanization, sustainable mobility infrastructure plays a critical role in reducing greenhouse gas emissions. This article assesses the Sunglider concept—an elevated, solar-powered transport system—through the New European Bauhaus (NEB) Compass, which emphasizes sustainability, inclusion, and esthetic value. Designed by architect Peter Kuczia and collaborators, Sunglider combines photovoltaic energy generation with modular, parametrically designed wooden pylons to form a lightweight, climate-positive mobility solution. The study evaluates the system’s technological feasibility, environmental performance, and urban integration potential, drawing on existing design documentation and simulation-based estimates. While Sunglider demonstrates strong alignment with NEB principles, including zero-emission operation and material circularity, its implementation is challenged by high initial investment, political and planning complexities, and integration into dense urban environments. Mitigation strategies—such as adaptive routing, visual screening, and universal station access—are proposed to address concerns around privacy, esthetics, and accessibility. The article positions Sunglider as a scalable and replicable model for mid-sized European cities, capable of advancing inclusive, carbon-neutral mobility while enhancing the urban experience. It concludes with policy and research recommendations, highlighting the importance of embedding infrastructure innovation within broader ecological and cultural transitions. Full article

Rising global electricity demand and the expansion of distribution networks require a critical assessment of component-level greenhouse gas contributions. Distribution transformers, although indispensable, have significant life-cycle carbon impacts due to the use of materials, manufacturing, and in-service losses. This study conducts a life-cycle assessment of a single-phase, 75 kVA oil-immersed distribution transformer manufactured in Newfoundland, one of the provinces with the cleanest, hydro-dominated grids in Canada, and evaluates it over a 40-year lifespan. Using a cradle-to-use boundary, the analysis quantifies embodied emissions from raw material extraction, manufacturing, and transportation, alongside operational emissions derived from empirically measured no-load and load losses. All the data are collected directly during the manufacturing process, ensuring high analytical fidelity. The energy efficiency of the transformer is analyzed in MATLAB version R2023b using measured no-load and load losses to generate efficiency, load characteristics under various operating conditions. Under varying load factor scenarios and based on Newfoundland’s 2025 grid intensity of 18 g CO₂e/kWh, the lifetime operational emissions are estimated to range from 0.19 t CO₂e under no-load operation to 4.4 t CO₂e under full-load conditions. A linear regression-based decarbonization model using Microsoft Excel projects grid intensity to reach net-zero around 2037, two years beyond the provincial target, indicating that post-2037 transformer losses will remain energetically relevant but carbon-neutral. Sensitivity analysis reveals that temporary overloading can substantially elevate lifetime emissions, emphasizing the value of smart-grid-enabled load management and optimal transformer sizing. Comparative assessment with fossil fuel-intensive provinces across Canada demonstrates the dominant influence of grid generation mix on life-cycle emissions. Additionally, refurbishment scenarios indicate up to 50% reduction in cradle-to-gate emissions through material reuse and oil reclamation. The findings establish a scalable framework for integrating grid decarbonization trajectories, life-cycle carbon modelling, and circular-economy strategies into sustainable distribution network planning and transformer asset management. Full article

Industrial packaging systems exert substantial environmental pressures, including material resource depletion, greenhouse gas emissions, and the accumulation of post-consumer waste. As global supply chains expand and sustainability regulations intensify, demand for environmentally responsible packaging solutions continues to rise. This study evaluates the environmental footprint of industrial packaging by integrating recent developments in life cycle assessment (LCA), ecological footprint (EF) methodologies, material innovations, and circular economy models. The assessment examines the sustainability performance of conventional and alternative packaging materials, plastics, aluminum, corrugated cardboard, and polylactic acid (PLA). Findings indicate that although corrugated cardboard is renewable, it still presents a measurable environmental burden, with evidence suggesting that incorporating solar energy into production can reduce its footprint by more than 12%. PLA-based trays demonstrate promising environmental performance when sourced from renewable feedstocks and directed to appropriate composting systems. Despite these advancements, several systemic challenges persist, including ecological overshoot in industrial regions where EF may exceed local biocapacity limitations in waste management infrastructure, and significant economic trade-offs. Transportation-related emissions and scalability constraints for bio-based materials further hinder large-scale adoption. Existing research suggests that integrating sustainable packaging across supply chains could meaningfully reduce environmental impacts. Achieving this transition requires coordinated cross-sector collaboration, standardized policy frameworks, and embedding advanced environmental criteria into packaging design and decision-making processes. Full article

Packaging is a fundamental component of food supply chains, enabling product protection, handling, and distribution from production to final consumption. In this context, the selection of secondary and tertiary packaging dimensions plays a critical role in improving logistics efficiency and reducing greenhouse gas (GHG) emissions associated with material use and transportation. This study proposes a sustainable packaging logistics (SPL) framework that systematically evaluates and optimizes packaging carton dimensions to enhance pallet utilization, transport efficiency, and packaging material efficiency. The framework is applied to a real-world case study from a meat processing company, demonstrating how alternative carton dimension configurations, while maintaining a constant product weight and functional equivalence, can significantly influence pallet-loading efficiency, transported payload, and associated CO₂-equivalent emissions. Rather than constituting a full life cycle assessment (LCA), the proposed approach adopts LCA-informed indicators to quantify material and transport related emission implications of packaging design choices. By integrating packaging design, palletization constraints, and logistics performance, the SPL framework provides a structured analytical basis for identifying packaging configurations that reduce material intensity and transport-related emissions. The results highlight the importance of packaging dimension optimization as a practical and scalable strategy for emission reduction in food supply chains. The proposed framework is intended to support decision-making in packaging design and to serve as a robust preparatory tool for future, more comprehensive LCA studies. Full article