Search Results (514)

Supply chains are a primary contributor to global greenhouse gas (GHG) emissions, rendering their decarbonization an essential dimension of sustainable development. Artificial intelligence (AI) provides a transformative pathway by facilitating proactive emission avoidance through operational efficiency, transparency, and resilience, in contrast to post-emission mitigation approaches such as carbon capture. This study explores the potential of AI to support indirect carbon dioxide removal (CDR) via supply chain decarbonization, adopting a comparative case study methodology. Empirical evidence is drawn from Tunisian agri-food, textile, and port logistics sectors, based on multi-source datasets spanning 6–12 months and covering fleet sizes ranging from 40 to 250,000 units. Methodological robustness was ensured through the use of pre-intervention baselines, statistical imputation for missing data (<5%), and validation against 20% out-of-sample test sets. Results indicate that AI-enabled interventions achieved annual avoided emissions between 500 and 1500 tCO₂ and reduced fuel consumption by 12–15%, with sensitivity analyses incorporating ±8–12% error margins. Among the approaches tested, hybrid models integrating operational and strategic layers demonstrated the most pronounced impact, aligning immediate efficiency gains with long-term systemic decarbonization. Furthermore, AI facilitates renewable energy integration, digital twin applications, and compliance with international sustainability frameworks, notably the Paris Agreement and the United Nations Sustainable Development Goals. Nevertheless, challenges related to data quality, computational demands, limited expertise, and organizational resistance constrain scalability. The findings underscore AI’s dual role as a technological enabler and systemic driver of supply chain decarbonization, advancing its positioning within global environmental sustainability transitions. Full article

Injecting carbon dioxide (CO₂) into underground geo-structures, such as depleted oil and gas reservoirs, reduces man-made CO₂ emissions into the atmosphere or removes what is already there. Studies have identified the risks of CO₂ leaks from these underground geo-structures through wellbores back into the atmosphere due to the high mobility of CO₂ in gaseous and supercritical states. This work aims at proposing a novel method of CO₂ storage using the Joule–Thomson cooling effect to effectively produce CO₂ hydrates on seafloors, with an objective to avoid the leakage risks of storage in depleted oil and gas reservoirs. Through the combination of thermodynamic data, analysis of hydrate stability, and engineering design with established working parameters, this study proposes an innovative concept and an enabling process for CO₂ placement onto seafloors for safe storage. The results of case analysis of typical seawater conditions reveal that the appropriate seafloor depth ranges for different applications (>1900 m for liquid CO₂ and 700–1900 m for CO₂ hydrate). An engineering design procedure for real applications is outlined. Full article

The increased energy efficiency of electrified vehicles and their potential to reduce CO₂ emissions through the use of environmentally friendly materials are highlighted as reasons for the shift to electrified vehicles. Brief trends on the development of electric vehicles (EVs) have been discussed, presenting outstanding improvement towards the actualization of the green economy. The state of the art in lubrication has been thoroughly investigated as one of the factors influencing energy efficiency and the lifespan of machine components. As a result, many reports on the effectiveness of specific lubricants in electric vehicle applications have been developed. Good thermal and corrosion-resistant lubricants are necessary because of the emergence of several new tribological difficulties, especially in areas that interact with greater temperatures and currents. To avoid fluidity and frictional problems that may be experienced over its lifetime, a good viscosity level of lubricant was also mentioned as a crucial component in the formulation of EV lubricant. New lubricants are also necessary for the gearbox systems of electric vehicles. Furthermore, battery electric vehicles (BEVs) require a suitable cooling system for the batteries; thus, a compatible nano-fluid is recommended. Sustainable battery cooling options support global energy efficiency and carbon emission reduction while extending the life of EV batteries. The path for future advancements or the creation of the most useful and efficient EV lubricants is provided by this review study. Full article

Wind turbines are reaching end-of-life in increasing volumes, presenting a growing sustainability challenge. In the United States, prevailing waste management practices, primarily landfilling, undermine circular economy objectives by discarding recoverable materials and energy. This study applies life cycle assessment (LCA) to quantify 16 midpoint environmental impacts across three end-of-life pathways—landfilling, recycling, and repurposing—of major turbine components (steel, concrete, and composite blades). An avoided burden approach is used to quantify environmental credits from substituting recovered materials for virgin equivalents. Results show that nearly all recycling and repurposing pathways outperform landfilling across most impact categories. Mechanical recycling of both glass and carbon fiber blades performed better than landfilling in all 16 categories, while pyrolysis and solvolysis improved outcomes in 14–15 of 16 categories (CO₂ eq emissions were higher for pyrolysis and solvolysis than for the landfilling option). Repurposing blades likewise showed broad advantages (15 of 16 categories; ozone depletion was slightly higher), extending material lifetimes before waste treatment. For conventional materials, steel and concrete recycling reduced impacts in most categories, with concrete outperforming landfilling in 15 of 16 categories (marine eutrophication was nearly equal to the landfilling option). The only mixed pathway was cement co-processing of GFRP, which split evenly between benefits and burdens. Sensitivity analysis underscores that improving the quality of recovered materials is critical to maximizing environmental benefits. Overall, both recycling and repurposing offer substantial environmental advantages over landfilling, reinforcing the importance of circular end-of-life strategies in sustaining wind energy across its full life cycle. Full article

In line with EU decarbonization targets for the heavy-duty transport sector, this study proposes an analytical methodology to assess the impact of diesel performance additives on fuel consumption in Euro 6 heavy-duty vehicles, the prevailing standard in the circulating European road tractor fleet. A fleet of five N3-category road tractors equipped with tanker semi-trailers was monitored over two phases. During the first 10-month baseline phase, the vehicles operated with standard EN 590 diesel (containing 6–7% FAME); in the second phase, they used a commercially available premium diesel containing performance-enhancing additives. Fuel consumption and route data were collected using a GPS-based system interfaced with the engine control unit via the OBD port and integrated with the fleet tracking platform. After applying data filtering to exclude low-quality or non-representative trips, a 1% reduction in fuel consumption was observed with the use of fuel with additives. Route-level analysis revealed higher savings (up to 5.1%) in high-load operating conditions, while most trips showed improvements between −1.6% and −3.4%. Temporal analysis confirmed the general trend across varying vehicle usage patterns. Aggregated fleet-level data proved to be the most robust approach to mitigate statistical variability. To evaluate the potential impact at scale, a European scenario was developed: a 1% reduction in fuel consumption across the 6.75 million heavy-duty vehicles in the EU could yield annual savings of 2 billion liters of diesel and avoid approximately 6 million tons of CO₂ emissions. Even partial adoption could lead to meaningful environmental benefits. Alongside emissions reductions, fuel additives also offer economic value by lowering operating costs, improving engine efficiency, and reducing maintenance needs. Full article

Background: The pressure on the transport sector to decarbonise intensifies the need to look beyond the usual recommendations (e.g., walking, cycling, technological innovations). Therefore, strategies to avoid or modify commutes to places of work have long been seen as an option to decarbonise. Recognised for achieving an optimal balance between working from home and working in an office, co-working spaces may also minimise the length of commutes and therefore reduce emissions, traffic congestion, road maintenance, stress experienced by drivers, and other negative externalities of traffic. Methods: This study quantifies the above using a digital model of England and Wales. Two distributions of co-working spaces have been compared in this paper (i.e., one co-working space (i) in each Middle-layer Super Output Area or (ii) at the nearest train station). Results: The overall reduction in travel time and distance exceeds 70% if everyone who commutes by car outside their home MSOA drives to a co-working space. Despite a change in the place of work having no impact on the cold start emissions, substantial emission savings can still be achieved. These range from 35.8% to 92.1% depending on the pollutant, scenario, and distribution of co-working spaces. Full article

This study suggests a newly developed model for estimating city-scale photovoltaic rooftop energy potential. This model aims to provide reasonable universal calculations regarding a city’s available space for mounting rooftop photovoltaic systems and their corresponding annual electricity production capacity. For the development of the model, a thorough literature review has been conducted, which compiles and presents mathematical expressions and performance coefficients. Necessary geographic and meteorological data have been obtained from European statistical repositories and the PVGIS tool, respectively. The main inputs refer to a city’s basic geographical data, population, total actual area, geographical coordinates, and, by extension, the optimum PV unit installation angle. This analysis presents a simple and accurate model applicable to European cities for assessing rooftop photovoltaic energy potential and suitable rooftop space for PV units. The findings can aid in advancing PV development in urban areas and contribute to creating environmentally neutral cities in the future. The methodology is verified with data retrieved from the Google Environmental Insights Explorer tool, which shows a deviation of 9.72%. According to the computational analysis for 40 European countries, the photovoltaic energy potential is between 12.31 GWh and 8200 GWh. These values correspond to a net available PV space between 0.03 km² and 31.86 km². The greatest photovoltaic coverage potential is equal to 117.4% for Patras, Greece, while the lowest is 7.27% for Oslo, Norway. Regarding the avoided greenhouse gas emissions, they are found to vary from 5.8 ktons of CO_2-equivalent for Valletta, Malta, and 8109.8 ktons for the city of London, United Kingdom. Finally, the final results of 86 additional cities located on the European continent are given. Full article

Against the background of global warming, the carbon emission of cities accounts for more than 70%, and its carbon sink increase and emission reduction have become the research focus. The water bodies and green spaces in the urban blue–green space have a synergistic carbon sequestration effect, but current research pays less attention to the small and medium scales. Therefore, taking the waterfront green space on both sides of Qinhuai New River in Nanjing as the research object, this paper explores the impact of the synergy between water and greenery on the carbon sequestration efficiency of green space. The study first estimates the carbon sequestration efficiency of green spaces by integrating measured Leaf Area Index (LAI) data with the mean carbon sequestration rate per unit leaf area for typical tree and shrub species. It then constructs a set of water–green spatial relationship indicators and applies a random forest regression model to identify the key factors influencing carbon sequestration efficiency. Finally, multiple scenario models are developed to simulate the effects of green spaces on CO₂ reduction, thereby validating the roles of the identified influencing factors. The study found that waterfront green spaces tended to exhibit slightly higher carbon sequestration efficiency compared with non-waterfront green spaces. The proportion of 10 m forest land area and the proportion of 10–20 m forest land area had a higher impact on the carbon sequestration capacity of waterfront green space; that is, the closer the distance between the green space and the water, the better the carbon sequestration capacity. In order to improve the carbon sequestration efficiency of the waterfront area, the green space should be arranged along the water bank as much as possible, the depth of the green space should be increased, the proportion of the forest land area should be increased, the arbor and shrub should be planted evenly, and ribbon planting should be avoided. The study confirmed the synergistic effect of water and greenery in carbon sequestration benefits, providing data support and theoretical reference for the optimization and renewal of urban waterfront green space, and contributing to the realization of urban waterfront green space planning, design, and renewal with the goal of a high carbon sink. Full article

Active control of injection quantity during start-up idle optimizes automotive diesel engine starting performance, aligning with low-carbon goals. Conventional methods rely on a calibrated demand torque map adjusted by speed, temperature, and pressure variations, requiring extensive labor for calibration and limiting energy-saving and emission improvements. To address this problem, this paper proposes a transient injection quantity active control method for the start-up process based on the variation characteristics of target speed. Firstly, the target speed variation characteristics of the start-up process are optimized by setting different accelerations. Secondly, a transient injection quantity control strategy for the start-up process is proposed based on the target speed variation characteristics. Finally, the control strategy proposed in this paper was compared with the conventional starting injection quantity control method to verify its effectiveness. The results show that the start-up idle control strategy proposed in this paper reduces the cumulative fuel consumption of the start-up process by 25.9% compared to the conventional control method while maintaining an essentially unchanged start-up time. The emissions of hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxides (NOx) exhibit peak reductions of 12.4%, 32.5%, and 62.9%, respectively, along with average concentration drops of 27.2%, 35.1%, and 41.0%. Speed overshoot decreases by 25%, and fluctuation time shortens by 23.6%. The results indicate that the proposed control method not only avoids complicated calibration work and saves labor and material resources but also effectively improves the starting performance, which is of great significance for the diversified development of automotive power sources. Full article

Geothermal energy has been recognized as a promising renewable resource for sustainable power generation; however, the efficiency of conventional geothermal power plants has remained relatively low, and high investment costs have limited their competitiveness with other renewable technologies. In this context, the present study introduced an innovative geothermal electricity generation system aimed at enhancing energy efficiency, cost-effectiveness, and sustainability. Unlike traditional configurations, the system raised the geothermal source temperature passively by employing advanced heat transfer mechanisms, eliminating the need for additional energy input. Comprehensive energy, exergy, and exergoeconomic analyses were carried out, revealing a net power output of 43,210 kW and an energy efficiency of 30.03%, notably surpassing the conventional Kalina cycle’s typical 10.30–19.48% range. The system’s annual electricity generation was 11,138.53 MWh, with an initial investment of USD 3.04 million and a short payback period of 3.20 years. A comparative assessment confirmed its superior thermoeconomic performance. In addition to its technoeconomic advantages, the environmental performance of the proposed configuration was quantified. A streamlined life cycle assessment (LCA) was performed with a functional unit of 1 MWh of net electricity. The proposed system exhibited a carbon footprint of 20–60 kg CO₂ eq MWh⁻¹ (baseline: 45 kg CO₂ eq MWh⁻¹), corresponding to annual emissions of 0.22–0.67 kt CO₂ eq for the simulated output of 11,138.53 MWh. Compared with coal- and gas-fired plants of the same capacity, avoided emissions of approximately 8.6 kt and 5.0 kt CO₂ eq per year were achieved. The water footprint was determined as ≈0.10 m³ MWh⁻¹ (≈1114 m³ yr⁻¹), which was substantially lower than the values reported for fossil technologies. These findings confirmed that the proposed system offered a sustainable alternative to conventional geothermal and fossil-based electricity generation. Multi-objective optimization using NSGA-II was carried out to maximize energy and exergy efficiencies while minimizing total cost. Key parameters such as turbine inlet temperature (459–460 K) and ammonia concentration were tuned for performance stability. A sensitivity analysis identified the heat exchanger, the first condenser (Condenser 1), and two separators (Separator 1, Separator 2) as influential on both performance and cost. The exergoeconomic results indicated Separator 1, Separator 2, and the turbine as primary locations of exergy destruction. With an LCOE of 0.026 USD/kWh, the system emerged as a cost-effective and scalable solution for sustainable geothermal power production without auxiliary energy demand. Full article

Aviation’s sustainability discourse often centres on flight emissions, but production and end-of-life phases also carry material, energy, and pollution impacts that are large enough to merit systematic intervention. With ~13,000 aircraft projected to retire over the next two decades—roughly 44% of the global fleet—the sector must scale responsible dismantling and material recovery to avoid lost opportunities for meeting future sustainability goals and to harness economic value from secondary parts and recycled feedstocks. Embedding major sustainability and circular economy principles into aircraft design, operations, and retirement can reduce waste, conserve critical materials, and lower lifecycle emissions while contributing directly to multiple SDGs. Furthermore, when considering particular aircraft types, thousands of narrow-body aircraft such as the Airbus A320 and Boeing 737 are due to reach their end of life over the next two decades. This research evaluates the economic and environmental feasibility of aluminium recycling from these aircraft, integrating material flow analysis, cost–benefit modelling, and a lifecycle emissions assessment. An economic assessment framework is developed and applied, with the results showing that approximately 24.7 tonnes of aluminium can be recovered per aircraft, leading to emissions savings of over 338,000 kg of CO₂e, a 95% reduction compared to primary aluminium production. However, scrap value alone cannot offset dismantling costs; the break-even scrap price is over USD 4200 per tonne. When additional revenue streams such as component resale and carbon credit incentives are incorporated, the model predicts a net profit of over USD 59,000 per aircraft. The scenario analysis confirms that aluminium recycling only becomes financially viable through multi-stream revenue models, supported by Extended Producer Responsibility (EPR) and carbon pricing. While barriers remain, aluminium recovery is a strategic opportunity to align aviation with circular economy and decarbonisation goals. Full article

This study presents a novel multi-objective optimization (MOO) model for the design of an off-grid hybrid renewable energy system (HRES) to support sustainable agriculture and rural development in Sub-Saharan Africa (SSA). Based upon a case study selected in Linia (Chad), three system architectures are compared under different levels of the reliability requirements (LPSP = 1%, 5%, and 10%). A Multi-Objective Particle Swarm Optimization (MOPSO) algorithm is applied to optimize the Levelized Cost of Energy (LCOE), CO₂ emissions mitigation, and social impact, referring to the Human Development Index (HDI) enhancement and the job creation (JC) opportunity, using the MATLAB R2024b environment. The calculation results show that among the three configuration schemes, the PV–Wind–Battery configuration obtains the optimal techno–economic–environmental coordination, with the lowest LCOE (0.0948 $/kWh) and the largest CO₂ emission reduction (9.58 × 10⁸ kg), and the Wind–Battery system gets the most social benefit. The method developed provides users with a decision-support method for renewable energy systems (RES) integration into rural agricultural settings, taking into consideration financial cost, environmental sustainability, and community development. This information is important for policymakers and practitioners advocating for decentralized, socially inclusive clean energy access initiatives in underserved regions. Full article

The increasing generation of agricultural waste poses both environmental and economic challenges, particularly in rural areas with limited infrastructure. Anaerobic digestion has emerged as a sustainable alternative, enabling the valorization of waste and the production of biogas and biofertilizer. This study evaluated the economic and environmental gains of mono- and co-digestion of equine manure and vegetable waste using biodigesters of different capacities across four simulated projects—Project 1 (15 m² biodigester with monodigestion), Project 2 (15 m² biodigester with co-digestion), Project 3 (20 m² biodigester with monodigestion), and Project 4 (20 m² biodigester with co-digestion). Economic feasibility was assessed through indicators such as Net Present Value (NPV), Internal Rate of Return (IRR), Modified IRR (MIRR), Profitability Index (PI), Benefit-Cost Ratio (B/C), Discounted Payback Period, sensitivity analysis, and Monte Carlo simulation, adopting a Minimum Attractiveness Rate (MAR) of 6.43% per year. Environmental benefits were estimated based on the annual reduction of CO₂ equivalent emissions. The results showed that all projects were economically viable and had the potential to mitigate up to 36 tons of CO₂eq per year. Additionally, an eco-efficiency indicator (NPV per CO₂eq avoided) was calculated to enable an integrated assessment of economic performance and environmental impact. Projects using 20 m³ biodigesters achieved the best results, with Project 3 being the most eco-efficient (USD256.05/tCO₂eq), while Project 4 yielded the highest absolute return in all economic analysis tools: NPV (USD 9063.81), IRR (25.10%), MIRR (10.95%), PI (USD 1.65), B/C (USD 1.65) and DPP (4.56 years). The integrated analysis underscores the significance of co-digestion and economies of scale in encouraging the adoption of this technology by small rural producers. Full article

Agricultural biowaste poses a major environmental challenge when improperly disposed of. An alternative to this is their utilization for producing natural fibers (NFs) to manufacture biocomposites, promoting a circular economy. However, the fact that a product is classified as renewable does not necessarily imply that its environmental performance is superior when compared to its conventional market counterpart. For this reason, this study conducted a Life Cycle Assessment (LCA) of biocomposites reinforced with coconut fiber and a polyester resin matrix, using a “cradle-to-gate” approach. Six scenarios were evaluated, grouped into S1 (2–5% fiber) and S2 (20–30% fiber), with and without chemical treatment, plus a reference scenario without fiber utilization. The IPCC 2021 GWP 100 and ReCiPe Midpoint (H) 2016 methods were applied. The results show that the scenarios without chemical treatment (RF-CCT) were environmentally more optimal, reducing CO₂ emissions by up to 7.4% (RF-CCT/H) and 1.70 kg CO₂-eq (RF-CCT/L) compared to conventional practices. The main reasons for these reductions are the avoidance of emissions associated with disposal, decreased reliance on conventional materials, and the omission of chemical treatment, which in turn mitigates critical impacts such as ozone depletion potential (ODP) linked to N₂O emissions from fertilizers (93% contribution) and terrestrial/marine toxicity. Full article

Newfoundland and Labrador have strong wind and water resources, making hybrid renewable energy systems an important option for the region. This paper presents the design and simulation of a system that combines wind turbines and micro-hydro power to deliver clean electricity for water treatment in remote communities. Many isolated areas still rely on diesel and other conventional sources, which create environmental concerns. Using HOMER Pro 3.17.1 software, the system was modeled based on local climate and resource conditions. Results show that it can produce over 35,000 kWh per year, enough to power a standard water treatment unit serving more than 240 people. By integrating wind and hydro with battery storage, the system ensures stable operation and reduces dependence on fossil fuels. The environmental analysis confirms that it avoids over 9 tons of CO₂ emissions annually. The novelty of this work is its site-specific approach, showing how renewable energy can improve both energy security and water quality in remote Canadian communities while providing a model for sustainable rural development. Full article