Search Results (149)

Recent studies have shown benefits of using tidal stream and wave energy in the electricity generation mix to improve supply–demand balancing on annual/subannual timeframes. This paper investigates this further by considering the variability of solar photovoltaic, onshore and offshore wind, wave, and tidal stream over multiple years. It also considers their ability to match with electricity demand when combined. Variability of demand and generation can have a significant impact on results. Over the sample of five years considered (2015–2019), demand varied by around 3%, and the availability of each renewable technology differed by up to 9%. This highlights the importance of considering multiple years of input data when assessing power system impacts, instead of relying on an ‘average’ year. It is also key that weather related correlations between renewable resources and with demand can be maintained in the data. Results from an economic dispatch model of Great Britain’s power system in 2030 are even more sensitive to the input data year, with costs and carbon emissions varying by up to 21% and 45%, respectively. Using wave or tidal stream as part of the future energy mix was seen to have a positive impact in all cases considered; 1 GW of wave and tidal (0.57% of total capacity) reduces annual dispatch cost by 0.2–1.3% and annual carbon emissions by 2.3–3.5%. These results lead to recommended best practises for modelling high renewable power systems, and will be of interest to modellers and policy makers. Full article

This work presents a comparative analysis of the results of silicon carbide synthesis through the carbonization of Si (001) and Si (111) substrates in the temperature range 1130–1140 °C. The synthesis involved chemical vapor deposition utilizing thermally stimulated methane reduction in a hydrogen gas stream. The experiments employed an Oxford Nanofab Plasmalab System 100 apparatus on substrates from which the native oxide was removed according to established protocols. To minimize random experimental variations (e.g., deviations from set parameters), short synthesis durations of 3 and 5 min were analyzed. The resultant thin films underwent evaluations through several techniques, including X-ray photoelectron spectroscopy, X-ray diffractometry, optical emission spectroscopy with glow discharge, and transmission electron microscopy. A comparison and analysis were conducted between the results from both substrate orientations. Full article

Carbon Capture and Storage (CCS) is a key technology for reducing anthropogenic greenhouse gas emissions, in which pipelines play a vital role in transporting CO₂ captured from industrial emitters to geological storage sites. To aid the efficient and safe operation of the CO₂ transport infrastructure, robust, accurate, and reliable solutions for monitoring pipelines transporting industrial CO₂ streams are urgently needed. This literature review study summarizes the monitoring objectives and identifies the problems and relevant mathematical algorithms developed for optimization of monitoring systems for pipeline transportation of water, oil, and natural gas, which can be relevant to the future CO₂ pipelines and pipeline networks for CCS. The impacts of the physical properties of CO₂ and complex designs and operation scenarios of CO₂ transport on the pipeline monitoring systems design are discussed. It is shown that the most relevant to liquid- and dense-phase CO₂ transport are the sensor placement optimization methods developed in the context of detecting leaks and flow anomalies for water distribution systems and pipelines transporting oil and petroleum liquids. The monitoring solutions relevant to flow assurance and monitoring impurities in CO₂ pipelines are also identified. Optimizing the CO₂ pipeline monitoring systems against several objectives, including the accuracy of measurements, the number and type of sensors, and the safety and environmental risks, is discussed. Full article

A core tertiary wastewater reactive filtration technology, where continuously renewed hydrous ferric oxide coated sand is created in an upflow continuous backwash filter, has been adopted in about 100 water resource recovery facilities in several countries. Primarily focused on ultralow phosphorus discharge requirements to address nutrient pollution impacts and harmful algae blooms, the technology has also demonstrated the capacity to address high-efficiency removals of Hg, As, Zn, N, and other pollutants of concern, in addition to water quality needs met by common sand filtration, including total suspended solids. Recent work has demonstrated the capability of an additive iron–ozone catalytic oxidation process to the core reactive filtration technology platform to address micropollutants such as pharmaceuticals. Most recently, direct injection of frangible biochar into the reactive sand filter bed as a consumable reagent demonstrates a novel biochar water treatment technology in a platform that yields dose-dependent carbon negativity. In this work, the reactive filtration technology performance is reviewed from field pilot-scale to full-scale installation scenarios for nutrient removal and recovery applications. We also review the potential of the technology for nutrient recovery with the addition of biochar and micropollutant destructive removal with catalytic oxidation. Research exploration of this reactive filtration technology includes life cycle assessment (LCA) and techno-economic assessment to evaluate the environmental and economic impacts of this advanced water treatment technology. A recent LCA study of a pilot-scale field research and full-scale municipal system with over 2200 inventory elements shows a dose-dependent carbon negativity when biochar is injected into the process stream of reactive filtration. In this study, LCA demonstrates that reactive filtration has the potential as a negative emissions technology with −1.21 kg CO₂e/m³, where the negative contribution from the dosed biochar is −1.53 kg CO₂e/m³. In this biochar water treatment configuration, the system not only effectively removes pollutants from wastewater but also contributes to carbon sequestration and nutrient recovery for agriculture, making it a potentially valuable approach for sustainable water treatment. Full article

This study aims to empirically examine the effects of CEO characteristics (gender, nationality, multiple directorships) on the carbon emissions of UK-listed firms. We focus on understanding how these factors influence carbon emissions across the overall sample and within specific industry sectors grounded on the upper echelons and stakeholder theories. We employed a quantitative research design using quantile regression analysis. Our dataset comprises 295 UK-listed firms from the STOXX 600 Index of European-listed companies, covering the period from 1999 to 2023. Data were sourced from BoardEx, Refinitiv DataStream, annual reports, and sustainability reports. Our results indicate that foreign CEOs are associated with higher carbon emissions across the overall sample of UK-listed firms, across the three levels of carbon emitters within the sensitive industries, and within low- and high-level emitters within the non-sensitive industries. CEOs with multiple directorships were found to have a significant association with higher carbon emissions, likely due to divided attention and obligations. As for the CEO gender, it is noteworthy that it has an insignificant effect on reducing carbon emissions in low emission companies within sensitive industries. In contrast, female CEOs were associated with lower carbon emissions in medium-emitting firms within non-sensitive industries. This study contributes to existing literature by employing sensitivity analysis (sensitive sectors and non-sensitive). The study also employs a novel econometric technique, quantile regression, which provides a comprehensive understanding of the relationship between independent and dependent variables across different points of the distribution. Full article

The accurate prediction of autonomous vessel CO₂ emissions is critical for achieving IMO 2050 carbon neutrality and optimizing low-carbon maritime operations. Traditional models face limitations in real-time multi-source data analysis and dynamic cross-variable dependency modeling, hindering data-driven decision-making for sustainable autonomous shipping. This study proposes a Multi-scale Channel-aligned Transformer (MCAT) model, integrated with a 5G–satellite–IoT communication architecture, to address these challenges. The MCAT model employs multi-scale token reconstruction and a dual-level attention mechanism, effectively capturing spatiotemporal dependencies in heterogeneous data streams (AIS, sensors, weather) while suppressing high-frequency noise. To enable seamless data collaboration, a hybrid transmission framework combining satellite (Inmarsat/Iridium), 5G URLLC slicing, and industrial Ethernet is designed, achieving ultra-low latency (10 ms) and nanosecond-level synchronization via IEEE 1588v2. Validated on a 22-dimensional real autonomous vessel dataset, MCAT reduces prediction errors by 12.5% MAE and 24% MSE compared to state-of-the-art methods, demonstrating superior robustness under noisy scenarios. Furthermore, the proposed architecture supports smart autonomous shipping solutions by providing demonstrably interpretable emission insights through its dual-level attention mechanism (visualized via attention maps) for route optimization, fuel efficiency enhancement, and compliance with CII regulations. This research bridges AI-driven predictive analytics with green autonomous shipping technologies, offering a scalable framework for digitalized and sustainable maritime operations. Full article

Amid intensified global climate mitigation efforts, integrating rail freight into carbon emissions trading schemes became critical under China’s “Dual-Carbon” strategy. Despite rail’s significantly lower emissions intensity compared to road transport, existing pricing frameworks inadequately internalized its environmental externalities, which limited its competitive advantage. To address this gap, this study systematically reviewed international and domestic practices of integrating transport into carbon trading systems and developed a novel “four-layer, three-dimensional” emissions trading scheme (ETS) framework tailored specifically for China’s rail freight sector. Employing a Stackelberg bilevel optimization model, this study analyzed how carbon quotas and pricing influenced rail operators’ pricing and investment decisions. The results showed that under optimized quotas and carbon prices, railway enterprises were able to generate surplus carbon credits, creating new revenue streams and enabling freight rate reductions. This “carbon revenue–freight rate feedback loop” not only delivered environmental benefits but also enhanced rail’s economic competitiveness. Overall, this study significantly advances the understanding of carbon-based pricing mechanisms in railway freight, providing robust theoretical insights and actionable policy guidance for achieving sustainable decarbonization in China’s transport sector. Full article

Heat integration is a crucial concept in process engineering and energy management. It refers to using heat exchangers and process modifications to maximize energy efficiency, lowering cost and/or carbon emissions within industrial processes through minimizing the external heating and cooling requirements (utility savings). There are two key aspects of heat integration. “Heat Exchanger Network” is an approach to designing efficient connections among the heat exchangers to transfer heat between several hot and cold streams. “Pinch Analysis” is a systematic methodology that determines the optimal energy recovery by identifying the “pinch point” to maximize heat recovery. The paper aims to review the actual status of research in the field of application of heat exchanger networks for industrial integrations and highlight the perspectives. Full article

Volatile Organic Compounds (VOCs) are essential for primary pharmaceutical manufacturing. Their permissible emission levels are strictly regulated due to their toxic effects both on human health and the environment. Activated carbon adsorption columns are used in industry to treat VOC gaseous waste streams from industrial plants, but their process efficiency suffers from quick and unpredictable saturation of the adsorbent material. This study presents the application of a validated, non-isothermal, multicomponent adsorption model using the Langmuir Isotherm and the Linear Driving Force model to examine multicomponent VOC mixture breakthrough. Specifically, three binary mixtures (hexane–acetone, hexane–dichloromethane, hexane–toluene) are simulated for four different bed lengths (0.25, 0.50, 0.75, 1 m) and six different superficial velocities (0.1, 0.2, 0.3, 0.5, 0.7, 0.9 m s⁻¹). Key breakthrough metrics reveal preferential adsorption of acetone and toluene over hexane, and hexane over dichloromethane, as well as breakthrough onset patterns. Temperature peaks are moderate while pressure drops increase for longer column lengths and higher flow rates. A new breakthrough onset metric is introduced, paving the way to improved operating regimes for more efficient industrial VOC capture bed utilisation via altering multicomponent mixture composition, feed flowrate, and column length. Full article

Achieving net-zero carbon emissions, this study introduces a sustainable pathway for reducing strontium sulfate (SrSO₄) and celestite ore to strontium sulfide (SrS) using biofuels (biomethane, bioethanol) derived from agro-industrial waste and green hydrogen. Traditional SrSO₄ reduction methods, which rely on fossil-derived reductants like coal and operate at energy-intensive temperatures (1100–1200 °C), generate significant greenhouse gases and toxic byproducts, highlighting the need for eco-friendly alternatives. Experimental results demonstrate that bioethanol outperformed other reductants, achieving 97% conversion of synthetic SrSO₄ at 950 °C within 24 min and 74% conversion of natural celestite ore over 6 h. Remarkably, this bioethanol-driven process matches the energy efficiency of the conventional black ash method while enabling carbon neutrality through renewable feedstock utilization, reducing CO₂ emissions by 30–50%. By valorizing agro-industrial waste streams, this strategy advances circular economy principles and aligns with Mexico’s national agenda for sustainable industrial practices, including its commitment to decarbonizing heavy industries. This study contributes to sustainable development goals and offers a scalable solution for decarbonizing strontium compound production in the chemical industry. Full article

The iron and steel industry, as a major energy consumer, was critically required to enhance operational efficiency and reduce CO₂ emissions. Conventional blast furnace processing of vanadium–titanium magnetite (VTM) in China had been associated with persistent challenges, including suboptimal TiO₂ recovery rates (<50%) and elevated carbon intensity (the optimal temperature range for TiO₂ recovery lies within 1400–1500 °C). Shaft furnace technology has emerged as a low-carbon alternative, offering accelerated reduction kinetics, operational flexibility, and reduced environmental impact. This study evaluated the low-carbon PLCsmelt process for VTM smelting through energy–mass balance modeling, comparing two gas-recycling configurations. The process integrates a pre-reduction shaft furnace and a melting furnace, where oxidized pellets are initially reduced to direct reduced iron (DRI) before being smelted into hot metal. In Route 1, CO₂ emissions of 472.59 Nm³/tHM were generated by pre-reduction gas (1600 Nm³/tHM, 64.73% CO, and 27.17% CO₂) and melting furnace top gas (93.98% CO). Route 2 incorporated hydrogen-rich gas through the blending of coke oven gas with recycled streams, achieving a 56.8% reduction in CO₂ emissions (204.20 Nm³/tHM) and altering the pre-reduction top gas composition to 24.88% CO and 40.30% H₂. Elevating the pre-reduction gas flow in Route 2 resulted in increased CO concentrations in the reducing gas (34.56% to 37.47%) and top gas (21.89% to 26.49%), while gas distribution rebalancing reduced melting furnace top gas flow from 261.03 to 221.93 Nm³/tHM. The results demonstrated that the PLCsmelt process significantly lowered carbon emissions without compromising metallurgical efficiency (CO₂ decreased about 74.48% compared with traditional blast furnace which was 800 Nm³/tHM), offering a viable pathway for sustainable VTM utilization. Full article

The concentrations of dissolved N₂O in river systems at the basin scale exhibit significant spatial and temporal variability, particularly under diverse landscape conditions. This study focused on a temperate basin—the Yiluo River (YLR) basin in China—to investigate the variations in dissolved N₂O concentrations and the indirect emission factors (EF_5r) between the dry and wet seasons. The differences among tributaries were analyzed to assess the impact of land use types. The findings revealed that N₂O concentrations and saturation levels were lower during the wet season in both the main streams and tributaries. In the dry season, the N₂O concentrations were strongly correlated with NH₄⁺-N, NO₃⁻-N, and oxidation–reduction potential (ORP) (R² = 0.743, p < 0.001), while in the wet season, the N₂O concentrations were correlated with dissolved phosphorus (DP), water temperature (Tw), NH₄⁺-N, and DOC (R² = 0.640, p < 0.001). Impervious land was identified as the primary source of nitrogen in both seasons, rather than cropland. Natural land, particularly shrubland, demonstrated a notable mitigating effect on N₂O accumulation and played a significant role in reducing NO₃⁻-N levels. The YLR basin exhibited lower EF_5r values (0.005–0.052%) compared to the default value recommended by the IPCC, with a significant decrease observed during the wet season (p < 0.001). Data analysis indicated that nutrient dynamics, particularly NO₃⁻-N, the ratio of dissolved organic carbon to NO₃⁻-N (DOC/NO₃⁻-N), and the ratio of NO₃⁻-N to DP (NO₃⁻-N/DP), were significantly correlated with EF_5r. These results underscore the need to re-evaluate regional N₂O emission potentials and provide new insights into mitigating N₂O emissions through strategic land use management. Full article

This study explores the co-pelletization of sludge with landfill-mined plastic waste as a method to create high-energy refuse-derived fuel (RDF), addressing both plastic and sludge waste streams. Key variables used in RDF pelletization included sludge-to-plastic mixing ratios (50:50, 75:25, and 100:0 wt%), mold temperatures (100 °C and 120 °C), and compression pressures (60–80 MPa). Results showed that the characteristics of pellets improved considerably as the mass percentage of plastic waste increased. The 75% sludge mixture produced pellets with high compressive strength (15.9–16.4 MPa), indicating rigid and ductile properties, and achieved a calorific value of up to 33.4 MJ/kg. Mercury levels of the RDF (0.02–0.04 mg/MJ) met solid recovered fuel standards. However, the elevated chlorine content (>3 wt%_db) highlighted the necessity of removing PVC from the plastic waste before pelletization. Carbon emission factors for the pellets (23–25 kg CO₂/GJ) were comparable to commercial RDFs and notably lower than coal, demonstrating their potential as a sustainable alternative fuel source. An assessment of the entire production and utilization chain, including sludge drying, plastic sorting, pelletization, and combustion, revealed that co-pelletization reduces greenhouse gas emissions by more than 24.3% compared to current practices. Full article

The adoption of the PPWR by the Council of the European Union (EU/2025/40) in 2025 intensifies the regulatory pressure on packaging manufacturers and food producers. This necessitates their adaptation of packaging to the new standards and selection of materials by various sustainability criteria and minimum standards. The legal text places particular emphasis on recyclability and the carbon footprint. The dairy industry holds significant economic importance in the DACH region (Germany, Austria, and Switzerland); this study therefore analyzed and compared the recyclability and carbon footprint of selected product categories and diverse packaging options for butter, yogurt, spreads, curd cheese, and cottage cheese. This study found large differences within the product categories, and also between the assessed countries, due to differing waste management systems (collection, sorting, and recycling) and waste streams. A key finding is the substantial discrepancy in glass packaging, which significantly exceeds the emission values of other packaging systems. In terms of recyclability, glass packaging performs well due to the effectiveness of the recycling systems regarding the future effective PPWR. However, significant variations in recyclability were observed between Germany and Austria for tray and cup materials made of PP and PS. Notably, there is a preference for packaging systems without a cardboard sleeve over those with one. This study provides critical insights into the environmental performance of packaging materials in the dairy sector. It highlights the challenges posed by regulatory changes and the urgent need for region-specific strategies. By identifying key areas for improvement in packaging design and waste management, this work lays the foundation for achieving compliance with the PPWR and advancing the transition toward a circular economy in the DACH region. Full article

The petroleum industry has been a key driver in the development of the world economy yet continues to attract increasing criticism due to its negative environmental impact via greenhouse gas emissions, resource inefficiency, and waste. Integrating lean and green practices is fast becoming a transformative approach to tackling these issues as it integrates process optimization with sustainability principles. This review paper examined the existing literature on lean and green integration, highlighting its benefits, models, critical success factors, and a roadmap for its implementation. Also, it identified sustainability challenges and offered strategic solutions. The findings showed that integrating lean and green offers potential for both process optimization and waste and carbon footprint reduction, particularly for the petroleum industry in Sub-Saharan Africa (SSA). This can be achieved by using appropriate tools and models. Sustainable value stream mapping (Sus-VSM) is a strategic tool that highlights the importance of sustainability metrics. These sustainability metrics address the implementation challenges of the convectional value stream mapping tool (VSM). This paper is one of the few initiatives to promote lean–green integration within the petroleum industry. Full article