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Search Results (540)

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Keywords = CO2 emissions and decarbonization

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15 pages, 6332 KB  
Article
Titanium Modulated the Occurrence States and Strain Aging Resistance of Residual Element Nitrogen in Scrap-Based Low-Alloy Steels
by Yuhe Huang, Haisheng Yang, Jun Lu, Jing Wang, Bicao Peng, Junheng Gao, Haitao Zhao, Honghui Wu, Chaolei Zhang, Shuize Wang and Xinping Mao
Materials 2025, 18(21), 4842; https://doi.org/10.3390/ma18214842 - 23 Oct 2025
Abstract
The steel industry is responsible for 7–9% of global CO2 emissions. Shifting from primary iron ore to recycled scrap in electric arc furnace (EAF) steelmaking offers significant decarbonization potential, reducing carbon intensity by 60–70%. However, increased scrap use in EAF operations leads [...] Read more.
The steel industry is responsible for 7–9% of global CO2 emissions. Shifting from primary iron ore to recycled scrap in electric arc furnace (EAF) steelmaking offers significant decarbonization potential, reducing carbon intensity by 60–70%. However, increased scrap use in EAF operations leads to higher nitrogen absorption, which can degrade mechanical properties. Nitrogen dissolves into molten steel, where it forms Cottrell atmospheres at dislocations in the following processing steps, intensifying strain aging and reducing ductility. This study establishes a precipitation criterion based on the TiN solubility product to prevent harmful liquid TiN formation, enabling effective nitrogen fixation via fine TiN precipitates (5–20 nm). Multiscale characterization techniques, such as TEM and EBSD, show that Ti reduces the number of mobile N atoms by 60–70%, evidenced by a 50–65% decrease in Snoek/SKK peak intensities. Excessive titanium can refine ferrite grain size and prevents harmful TiN inclusions. Titanium microalloying presents a cost-effective, sustainable strategy to reduce strain aging in scrap-rich EAF steels, enabling more sustainable steel production without sacrificing material properties. Full article
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18 pages, 366 KB  
Article
Financing the Green Transition: How Green Finance and Renewable Energy Drive CO2 Mitigation
by Manal Elhaj, Fatma Mabrouk and Layan Alotaibi
Energies 2025, 18(21), 5563; https://doi.org/10.3390/en18215563 - 22 Oct 2025
Abstract
The accelerating demand for climate action has underscored the need to link financial innovation with clean energy adoption. This study examines the interplay between green finance, renewable energy consumption, and CO2 emissions across 15 countries from 2013 to 2022. Green finance is [...] Read more.
The accelerating demand for climate action has underscored the need to link financial innovation with clean energy adoption. This study examines the interplay between green finance, renewable energy consumption, and CO2 emissions across 15 countries from 2013 to 2022. Green finance is proxied by green bond issuances and environmental protection expenditures, capturing both market-based and fiscal flows. Using panel econometric methods, including fixed effects with Driscoll–Kraay corrections, Prais–Winsten regressions with PCSE, and Feasible Generalized Least Squares (FGLS), the analysis accounts for heteroscedasticity, autocorrelation, and cross-sectional dependence. Results show how green finance significantly reduces emissions, both directly and indirectly, through its positive influence on renewable energy deployment. Renewable energy consumption shows a robust negative association with CO2 emissions, confirming its pivotal role in energy transition. A mediation analysis further demonstrates that renewable energy partially transmits the effect of green finance on environmental performance. The findings highlight the dual function of green finance in mobilizing investment and accelerating decarbonization, offering timely insights for policymakers seeking effective pathways toward sustainable, low-carbon economies. Full article
(This article belongs to the Special Issue Future Economic Scenarios for Renewable Energy and Climate Policy)
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19 pages, 3418 KB  
Article
Effect of Performance Packages on Fuel Consumption Optimization in Heavy-Duty Diesel Vehicles: A Real-World Fleet Monitoring Study
by Maria Antonietta Costagliola, Luca Marchitto, Marco Piras and Alessandra Berra
Energies 2025, 18(20), 5542; https://doi.org/10.3390/en18205542 - 21 Oct 2025
Viewed by 126
Abstract
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. [...] Read more.
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
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25 pages, 645 KB  
Article
Greenhouse Gas Analysis of Sustainable Sugar Beet Cultivation, Taking into Account the Technological Value and Quality of Various Varieties
by Magdalena Wróbel-Jędrzejewska, Łukasz Przybysz, Ewelina Włodarczyk, Andrzej Baryga, Andrzej Jaśkiewicz, Łukasz Ściubak and Krzysztof Sitko
Sustainability 2025, 17(20), 9316; https://doi.org/10.3390/su17209316 - 20 Oct 2025
Viewed by 221
Abstract
Sustainable production also involves analyzing greenhouse gas (GHG) emissions throughout the entire cultivation and processing cycle. The emissions balance for different sugar beet varieties is a key element of environmental assessment in sustainable production systems. It is consistent with the objectives of the [...] Read more.
Sustainable production also involves analyzing greenhouse gas (GHG) emissions throughout the entire cultivation and processing cycle. The emissions balance for different sugar beet varieties is a key element of environmental assessment in sustainable production systems. It is consistent with the objectives of the European Green Deal and aims to decarbonize agri-food technology. This study aims to assess and compare GHG emissions associated with the cultivation of three sugar beet variants (Viola, Jaromir, and Pulitzer) taking into account their technological and quality characteristics. The varieties were selected based on their registration in the National Register and their importance in agricultural practice in Poland, as well as their contrasting technological profiles, which allow for the assessment of the relationship between raw material quality and GHG balance. The study combines life cycle assessment (LCA) with physiological parameters such as CO2 assimilation, sugar content, yield, fuel consumption, and fertilizer use. The aim is to identify the correlation between the technological value of a variety and its environmental impact. It has been shown that genotypic characteristics have a significant impact on both yield and emissions. The Viola and Jaromir varieties showed a favorable balance between photosynthetic efficiency and greenhouse gas emissions, while the Pulitzer variety, despite low emissions per kilogram of product, showed poorer yield performance. The importance of using integrated assessment methods combining production efficiency, environmental efficiency, and crop quality was emphasized. Such an approach is essential for the development of sustainable agricultural practices in line with the EU’s climate neutrality goals. Further research is needed to optimize agrotechnical strategies tailored to the requirements of individual varieties, contributing to climate-resilient and environmentally friendly crop production. Full article
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29 pages, 18272 KB  
Article
Energy Retrofit of Heritage Buildings Through Photovoltaic and Community Energy Approaches: A Case Study Analysis
by Daniele Vitella, Leone Barbaro, Emanuele de Lieto Vollaro and Gabriele Battista
Buildings 2025, 15(20), 3768; https://doi.org/10.3390/buildings15203768 - 19 Oct 2025
Viewed by 236
Abstract
The building sector accounts for nearly 40% of total energy consumption in Europe, with heritage buildings posing a critical challenge due to conservation constraints. This study investigates two protected heritage sites—Palazzo Ruspoli in Cerveteri and Palazzo Vitelleschi in Tarquinia—to identify effective energy retrofit [...] Read more.
The building sector accounts for nearly 40% of total energy consumption in Europe, with heritage buildings posing a critical challenge due to conservation constraints. This study investigates two protected heritage sites—Palazzo Ruspoli in Cerveteri and Palazzo Vitelleschi in Tarquinia—to identify effective energy retrofit strategies integrating high-efficiency windows, HVAC and lighting systems, and photovoltaic (PV) solutions for both on-site and virtual self-consumption within Renewable Energy Communities (RECs). Energy surveys, modeling, and simulations were performed to evaluate technical, environmental, and economic impacts. The results show contrasting outcomes between the two cases: at Palazzo Vitelleschi, the combination of efficient systems and rooftop PV reduced non-renewable primary energy demand and CO2 emissions by 73.5%, with a 10.7-year payback period; at Palazzo Ruspoli, REC-based virtual self-consumption achieved net-negative carbon emissions (−240%), a 95% reduction in non-renewable energy demand, and a 19.4-year payback period. These findings demonstrate that heritage buildings can move beyond carbon neutrality and actively offset emissions through shared renewable generation. The proposed simulation-based framework provides a replicable method to balance conservation and sustainability, supporting the decarbonization of the historical built environment. Full article
(This article belongs to the Topic Sustainable Building Development and Promotion)
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24 pages, 4388 KB  
Article
Simulation of a Hybrid Plant with ICE/HT-PEMFC and On-Site Hydrogen Production from Methane Steam Reforming
by Marco Palomba, Maria Cristina Cameretti, Luigi Pio Di Noia and Raffaele Russo
Energies 2025, 18(20), 5448; https://doi.org/10.3390/en18205448 - 16 Oct 2025
Viewed by 287
Abstract
Hydrogen-based technologies, prominently fuel cells, are emerging as strategic solutions for decarbonization. They offer an efficient and clean alternative to fossil fuels for electricity generation, making a tangible contribution to the European Green Deal climate objectives. The primary issue is the production and [...] Read more.
Hydrogen-based technologies, prominently fuel cells, are emerging as strategic solutions for decarbonization. They offer an efficient and clean alternative to fossil fuels for electricity generation, making a tangible contribution to the European Green Deal climate objectives. The primary issue is the production and transportation of hydrogen. An on-site hydrogen production system that includes CO2 capture could be a viable solution. The proposed power system integrates an internal combustion engine (ICE) with a steam methane reformer (SMR) equipped with a CO2 capture and energy storage system to produce “blue hydrogen”. The hydrogen fuels a high-temperature polymer electrolyte membrane (HT-PEM) fuel cell. A battery pack, incorporated into the system, manages rapid fluctuations in electrical load, ensuring stability and continuity of supply and enabling the fuel cell to operate at a fixed point under nominal conditions. This hybrid system utilizes natural gas as its primary source, reducing climate-altering emissions and representing an efficient and sustainable solution. The simulation was conducted in two distinct environments: Thermoflex code for the integration of the engine, reformer, and CO2 capture system; and Matlab/Simulink for fuel cell and battery pack sizing and dynamic system behavior analysis in response to user-demanded load variations, with particular attention to energy flow management within the simulated electrical grid. The main results show an overall efficiency of the power system of 39.9% with a 33.5% reduction in CO2 emissions compared to traditional systems based solely on internal combustion engines. Full article
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21 pages, 2379 KB  
Article
Integrated Evaluation of Bio-Based Phase Change Materials to Reduce Operational and Embodied Carbon in Service Buildings Across Multiple Climate Zones
by Abdessamad Idouanaou, Mustapha Malha, Saïd Kardellass, Abdellah Bah, Omar Ansari, Rabab El Attar and Oumayma Cherqi
Buildings 2025, 15(20), 3720; https://doi.org/10.3390/buildings15203720 - 16 Oct 2025
Viewed by 331
Abstract
This study investigates the potential of bio-based phase change materials (bio-PCMs) to reduce both operational and embodied carbon in Moroccan service buildings. Using EnergyPlus 8.3 simulations and life cycle assessment (LCA), the research evaluates the integration of five bio-PCM types across six Moroccan [...] Read more.
This study investigates the potential of bio-based phase change materials (bio-PCMs) to reduce both operational and embodied carbon in Moroccan service buildings. Using EnergyPlus 8.3 simulations and life cycle assessment (LCA), the research evaluates the integration of five bio-PCM types across six Moroccan climate zones. Results show that climate-specific PCMs can lower heating and cooling energy demands by up to 20.3% and 28.0%, respectively, leading to operational CO2 emission reductions between 17.0% and 24.0%. Bio-PCM Q25 performed best in Coastal, Mediterranean, and Saharan zones, Q23 in Continental and Mountainous areas, and Q29 in hot-arid climates. In parallel, bio-based PCM M27 exhibited an embodied carbon of only 0.08 kgCO2/kg over 97% lower than conventional PCMs like paraffin or stearic acid. These findings confirm that optimized bio-PCM integration, combined with passive design strategies, offers a robust solution to decarbonize buildings in hot and diverse climates like Morocco. The study provides practical guidelines for material selection and policy direction toward climate-adapted, low-carbon construction. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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18 pages, 2838 KB  
Article
Evaluating the Role of Hydrogen as an Energy Carrier: Perspectives on Low-Emission Applications
by Dominika Polakovičová and Miroslav Variny
Hydrogen 2025, 6(4), 86; https://doi.org/10.3390/hydrogen6040086 - 13 Oct 2025
Viewed by 332
Abstract
Application of low-emission hydrogen production methods in the decarbonization process remains a highly relevant topic, particularly in the context of sustainable hydrogen value chains. This study evaluates hydrogen applications beyond industry, focusing on its role as an energy carrier and applying multi-criteria decision [...] Read more.
Application of low-emission hydrogen production methods in the decarbonization process remains a highly relevant topic, particularly in the context of sustainable hydrogen value chains. This study evaluates hydrogen applications beyond industry, focusing on its role as an energy carrier and applying multi-criteria decision analysis (MCDA) to assess economics, environmental impact, efficiency, and technological readiness. The analysis confirmed that hydrogen use for heating was the most competitive non-industrial application (ranking first in 66%), with favorable efficiency and costs. Power generation placed among the top two alternatives in 75% of cases. Transport end-use was less suitable due to compression requirements, raising emissions to 272–371 g CO2/kg H2 and levelizing the cost of hydrogen (LCOH) to 13–17 EUR/kg. When H2 transport was included, new pipelines and compressed H2 clearly outperformed other methods for short- and long-distances, adding only 3.2–3.9% to overall LCOH. Sensitivity analysis confirmed that electricity price variations had a stronger influence on LCOH than capital expenditures. Comparing electrolysis technologies yielded that, proton-exchange membrane and solid oxide reduced costs by 12–20% and CO2 emissions by 15–25% compared to alkaline. The study highlights heating end-use and compressed hydrogen and pipeline transport, proving MCDA to be useful for selecting scalable pathways. Full article
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17 pages, 1627 KB  
Article
Synergistic Effects of Air Pollution and Carbon Reduction Policies in China’s Iron and Steel Industry
by Jingan Zhu, Zixi Li, Xinling Jiang and Ping Jiang
Energies 2025, 18(20), 5379; https://doi.org/10.3390/en18205379 - 13 Oct 2025
Viewed by 338
Abstract
As an energy-intensive sector, China’s iron and steel industry is crucial for achieving “Dual Carbon” goals. This study fills the research gap in systematically comparing the synergistic effects of multiple policies by evaluating five key measures (2020–2023) in ultra-low-emission retrofits and clean energy [...] Read more.
As an energy-intensive sector, China’s iron and steel industry is crucial for achieving “Dual Carbon” goals. This study fills the research gap in systematically comparing the synergistic effects of multiple policies by evaluating five key measures (2020–2023) in ultra-low-emission retrofits and clean energy alternatives. Using public macro-data at the national level, this study quantified cumulative reductions in air pollutants (SO2, NOx, PM, VOCs) and CO2. A synergistic control effect coordinate system and a normalized synergistic emission reduction equivalent (APeq) model were employed. The results reveal significant differences: Sintering machine desulfurization and denitrification (SDD) showed the highest APeq but increased CO2 emissions in 2023. Dust removal equipment upgrades (DRE) and unorganized emission control (UEC) demonstrated stable co-reduction effects. While electric furnace short-process steelmaking (ES) and hydrogen metallurgy (HM) showed limited current benefits, they represent crucial deep decarbonization pathways. The framework provides multi-dimensional policy insights beyond simple ranking, suggesting balancing short-term pollution control with long-term transition by prioritizing clean alternatives. Full article
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31 pages, 4536 KB  
Article
Fuzzy Logic–Enhanced PMC Index for Assessing Policies for Decarbonization in Higher Education: Evidence from a Public University
by Fatma Şener Fidan
Sustainability 2025, 17(19), 8966; https://doi.org/10.3390/su17198966 - 9 Oct 2025
Viewed by 452
Abstract
Higher education institutions play a critical role in the transition to a low-carbon future due to their research capacity and societal influence. Accordingly, the calculation of greenhouse gas (GHG) emissions and the prioritization of mitigation strategies are of particular importance. In this study, [...] Read more.
Higher education institutions play a critical role in the transition to a low-carbon future due to their research capacity and societal influence. Accordingly, the calculation of greenhouse gas (GHG) emissions and the prioritization of mitigation strategies are of particular importance. In this study, a comprehensive campus-level GHG inventory was prepared for a public university in Türkiye in alignment with the ISO 14064-1:2018 standard, and mitigation strategies were evaluated. To prioritize these strategies, both the classical Policy Modeling Consistency (PMC) index and, for the first time in the literature, a fuzzy extension of the PMC model was applied. The results reveal that the total GHG emissions for 2023 amounted to 4888.63 tCO2e (1.19 tCO2e per capita), with the largest shares originating from investments (31%) and purchased electricity (28.38%). While the classical PMC identified only two high-priority actions, the fuzzy PMC reduced score dispersion, resolved ranking ties, and expanded the number of high-priority actions to seven. The top strategies include awareness programs, energy-efficiency measures, virtual meeting practices, advanced electricity monitoring, and improved data management systems. By comparing the classical and fuzzy approaches, the study demonstrates that integrating fuzzy logic enhances the transparency, reproducibility, and robustness of strategy prioritization, thereby offering a practical roadmap for campus decarbonization and sustainability policy in higher education institutions. Full article
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28 pages, 2740 KB  
Systematic Review
A Conceptual Framework for Enabling Structural Steel Reuse Utilizing Circular Economy in Modular Construction
by Shrouk Gharib and Osama Moselhi
Sustainability 2025, 17(19), 8945; https://doi.org/10.3390/su17198945 - 9 Oct 2025
Viewed by 596
Abstract
Steel production is a major contributor to resource use and greenhouse gas emissions, accounting for nearly 8% of global CO2 emissions, with structural steel accounting for more than half of this share. As the construction sector moves toward decarbonization, strategies for reuse, [...] Read more.
Steel production is a major contributor to resource use and greenhouse gas emissions, accounting for nearly 8% of global CO2 emissions, with structural steel accounting for more than half of this share. As the construction sector moves toward decarbonization, strategies for reuse, particularly within Modular and Offsite Construction (MOC), are receiving growing attention. This study presents a digitally integrated framework for the recovery, testing, and reuse of structural steel in MOC, grounded in Circular Economy (CE) principles. The framework is based on a systematic review of 162 academic, industry, and case study records and is structured across four stages: (1) material recovery, (2) testing and certification, (3) integration into MOC, and (4) performance evaluation. Building Information Modeling (BIM) and Material Passports (MPs) provide digital infrastructure for traceability, documentation, and compliance with established protocols, such as SCI P427 and P440. Reuse outcomes are assessed using the Modular Reuse Ratio (MRR), Carbon Savings (CS), Lifecycle Cost Savings (LCS), and a tailored Material Circularity Indicator (MCI). By aligning certification requirements with digital processes, the framework addresses current gaps in traceability, standardization, and decision support. It provides a scalable and replicable model that advances structural steel reuse, contributes to sector-wide decarbonization, and supports alignment with emerging CE and performance-based certification schemes. Full article
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30 pages, 1769 KB  
Review
Decarbonizing the Cement Industry: Technological, Economic, and Policy Barriers to CO2 Mitigation Adoption
by Oluwafemi Ezekiel Ige and Musasa Kabeya
Clean Technol. 2025, 7(4), 85; https://doi.org/10.3390/cleantechnol7040085 - 9 Oct 2025
Viewed by 1039
Abstract
The cement industry accounts for approximately 7–8% of global CO2 emissions, primarily due to energy-intensive clinker production and limestone calcination. With cement demand continuing to rise, particularly in emerging economies, decarbonization has become an urgent global challenge. The objective of this study [...] Read more.
The cement industry accounts for approximately 7–8% of global CO2 emissions, primarily due to energy-intensive clinker production and limestone calcination. With cement demand continuing to rise, particularly in emerging economies, decarbonization has become an urgent global challenge. The objective of this study is to systematically map and synthesize existing evidence on technological pathways, policy measures, and economic barriers to four core decarbonization strategies: clinker substitution, energy efficiency, alternative fuels, as well as carbon capture, utilization, and storage (CCUS) in the cement sector, with the goal of identifying practical strategies that can align industry practice with long-term climate goals. A scoping review methodology was adopted, drawing on peer-reviewed journal articles, technical reports, and policy documents to ensure a comprehensive perspective. The results demonstrate that each mitigation pathway is technically feasible but faces substantial real-world constraints. Clinker substitution delivers immediate reduction but is limited by SCM availability/quality, durability qualification, and conservative codes; LC3 is promising where clay logistics allow. Energy-efficiency measures like waste-heat recovery and advanced controls reduce fuel use but face high capital expenditure, downtime, and diminishing returns in modern plants. Alternative fuels can reduce combustion-related emissions but face challenges of supply chains, technical integration challenges, quality, weak waste-management systems, and regulatory acceptance. CCUS, the most considerable long-term potential, addresses process CO2 and enables deep reductions, but remains commercially unviable due to current economics, high costs, limited policy support, lack of large-scale deployment, and access to transport and storage. Cross-cutting economic challenges, regulatory gaps, skill shortages, and social resistance including NIMBYism further slow adoption, particularly in low-income regions. This study concludes that a single pathway is insufficient. An integrated portfolio supported by modernized standards, targeted policy incentives, expanded access to SCMs and waste fuels, scaled CCUS investment, and international collaboration is essential to bridge the gap between climate ambition and industrial implementation. Key recommendations include modernizing cement standards to support higher clinker replacement, providing incentives for energy-efficient upgrades, scaling CCUS through joint investment and carbon pricing and expanding access to biomass and waste-derived fuels. Full article
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20 pages, 2263 KB  
Review
Alternative Fuels for General Aviation Piston Engines: A Comprehensive Review
by Florentyna Morawska, Paula Kurzawska-Pietrowicz, Remigiusz Jasiński and Andrzej Ziółkowski
Energies 2025, 18(19), 5299; https://doi.org/10.3390/en18195299 - 7 Oct 2025
Viewed by 708
Abstract
This review synthesizes recent research on alternative fuels for piston-engine aircraft and related propulsion technologies. Biofuels show substantial promise but face technological, economic, and regulatory barriers to widespread adoption. Among liquid options, biodiesel offers a high cetane number and strong lubricity yet suffers [...] Read more.
This review synthesizes recent research on alternative fuels for piston-engine aircraft and related propulsion technologies. Biofuels show substantial promise but face technological, economic, and regulatory barriers to widespread adoption. Among liquid options, biodiesel offers a high cetane number and strong lubricity yet suffers from poor low-temperature flow and reduced combustion efficiency. Alcohol fuels (bioethanol, biomethanol) provide high octane numbers suited to high-compression engines but are limited by hygroscopicity and phase-separation risks. Higher-alcohols (biobutanol, biopropanol) combine favorable heating values with stable combustion and emerge as particularly promising candidates. Biokerosene closely matches conventional aviation kerosene and can function as a drop-in fuel with minimal engine modifications. Emissions outcomes are mixed across studies: certain biofuels reduce NOx or CO, while others elevate CO2 and HC, underscoring the need to optimize combustion and advance second- to fourth-generation biofuel production pathways. Beyond biofuels, hydrogen engines and hybrid-electric systems offer compelling routes to lower emissions and improved efficiency, though they require new infrastructure, certification frameworks, and cost reductions. Demonstrated test flights with biofuels, synthetic fuels, and hydrogen confirm technical feasibility. Overall, no single option fully replaces aviation gasoline today; instead, a combined trajectory—biofuels alongside hydrogen and hybrid-electric propulsion—defines a pragmatic medium- to long-term pathway for decarbonizing general aviation. Full article
(This article belongs to the Special Issue Internal Combustion Engine Performance 2025)
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72 pages, 13041 KB  
Article
Decarbonizing the Building Sector: The Integrated Role of Environmental, Social, and Governance Indicators
by Nicola Magaletti, Valeria Notarnicola, Mauro Di Molfetta and Angelo Leogrande
Buildings 2025, 15(19), 3601; https://doi.org/10.3390/buildings15193601 - 7 Oct 2025
Viewed by 389
Abstract
Climate change mitigation for the built environment has become a subject of greatest urgency, as buildings account for nearly 40% of total energy consumption and nearly one-third of total CO2 emissions. While environmental, social, and governance (ESG) indicators are increasingly used to [...] Read more.
Climate change mitigation for the built environment has become a subject of greatest urgency, as buildings account for nearly 40% of total energy consumption and nearly one-third of total CO2 emissions. While environmental, social, and governance (ESG) indicators are increasingly used to monitor sustainability performance, their collective role in impacting building-related emissions is yet largely under-investigated. The current research closes that gap through an examination of the ESG dimension–CO2 emissions intersection of 180 nations from 2000 to 2022, in the hope of illuminating how environmental, social, and governance elements interact to facilitate decarbonization. The research is guided by a multi-method design, including econometric examination, cluster modeling, and machine learning techniques, which provide causal evidence and predictive analysis, respectively. The findings reveal that the deployment of renewable energy significantly reduces emissions, while per capita energy use and PM2.5 air pollution exacerbate this effect. The social indicators show mixed results: learning, women’s parliamentary representation, and women’s workforce representation reduce emissions, while food production and growth among the lowest-income individuals demonstrate higher emissions. Governance demonstrates mixed results as well, with good regulation reducing emissions under specific conditions yet primarily supporting high-income countries with superior infrastructure. The examination of clusters reveals that ESG-balanced performance is retained by countries in the low-emission clusters, whereas decentralized ESG pillars are associated with higher emissions. Machine learning confirms the existence of non-linear effects and identifies PM2.5 exposure and renewable energy deployment as the strongest predictors of the relationship. In summary, the findings suggest that successful policies for decarbonizing the built environment are constructed upon the consistency of environmental, social, and governance plans, rather than single steps. Full article
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18 pages, 1311 KB  
Article
Thermo-Energetic Analysis of Electrolytic Oxygen Valorization via Biomass Oxy-Fuel Combustion: A Case Study Applied to a Power-to-Liquid Route for Methanol Synthesis
by Flávio S. Pereira, Argimiro R. Secchi and Alexandre Szklo
Thermo 2025, 5(4), 41; https://doi.org/10.3390/thermo5040041 - 7 Oct 2025
Viewed by 384
Abstract
The decarbonization of hard-to-defossilize sectors, such as international maritime transport, requires innovative, and at times disruptive, energy solutions that combine efficiency, scalability, and climate benefits. Therefore, power-to-liquid (PtL) routes have stood out for their potential to use low-emission electricity for the production of [...] Read more.
The decarbonization of hard-to-defossilize sectors, such as international maritime transport, requires innovative, and at times disruptive, energy solutions that combine efficiency, scalability, and climate benefits. Therefore, power-to-liquid (PtL) routes have stood out for their potential to use low-emission electricity for the production of synthetic fuels, via electrolytic hydrogen and CO2 capture. However, the high energy demand inherent to these routes poses significant challenges to large-scale implementation. Moreover, PtL routes are usually at most neutral in terms of CO2 emissions. This study evaluates, from a thermo-energetic perspective, the optimization potential of an e-methanol synthesis route through integration with a biomass oxy-fuel combustion process, making use of electrolytic oxygen as the oxidizing agent and the captured CO2 as the carbon source. From the standpoint of a first-law thermodynamic analysis, mass and energy balances were developed considering the full oxygen supply for oxy-fuel combustion to be met through alkaline electrolysis, thus eliminating the energy penalty associated with conventional oxygen production via air separation units. The balance closure was based on a small-scale plant with a capacity of around 100 kta of methanol. In this integrated configuration, additional CO2 surpluses beyond methanol synthesis demand can be directed to geological storage, which, when combined with bioenergy with carbon capture and storage (BECCS) strategies, may lead to net negative CO2 emissions. The results demonstrate that electrolytic oxygen valorization is a promising pathway to enhance the efficiency and climate performance of PtL processes. Full article
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