Energy nexus最新文献_第3页

Controlled autoxidation of HVGO to produce high-value carbon fibers precursors: the role of oxygen availability and naphthenic-aromatic hydrocarbons HVGO受控自氧化生产高价值碳纤维前体：氧可用性和环烷基芳烃的作用

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2025-12-09 DOI: 10.1016/j.nexus.2025.100623

Mustafa M. Amin , Ajay Sharma , Mohammad M. Hossain , Muhammad N. Siddiquee

This study investigated the application of heavy vacuum gas oil (HVGO) as a feedstock for high-value carbon fiber precursor production through controlled autoxidation. HVGO, initially had no asphaltenes, was subjected to varying oxidation conditions, such as blowing without mixing and bubbling with mixing at different temperatures with and without addition of tetralin (a naphthenic-aromatic hydrocarbon), to enhance its asphaltenes content and modify its physicochemical properties required for carbon fiber formation. The elemental analysis and physicochemical characterization of the HVGO samples after oxidation showed that the autoxidation significantly enhanced the asphaltenes content, with the highest asphaltenes yield of 47.2 wt. %, viscosity of 117.6 Pa.s, and softening point of 210 °C achieved after 72 hours at 190°C using 5% tetralin and air blowing without mixing. It also found that tetralin addition maintaining limited oxygen conditions would help to form heavier products, desirable as carbon fiber precursor. The melt spinning of the asphaltenes from oxidized HVGO with tetralin, provided green fibers with diameters of 70 µm and carbonized fibers with diameters of 40 to 50 µm, as detected by SEM imaging analysis. The mass residues of the oxidized HVGO samples and the carbon fibers were confirmed by TGA analysis. All these observations indicated that the controlled autoxidation, especially when tetralin was added, was a potential pathway to turn low-value HVGO into high-value carbon fiber precursors. Understanding the current research can also be applied to produce high-value carbon materials for CNT, graphene, and carbon materials for energy storage applications.

研究了重真空瓦斯油（HVGO）作为原料，通过控制自氧化生产高价值碳纤维前驱体的应用。HVGO最初不含沥青质，在不同的氧化条件下，如不混合吹气和在不同温度下混合鼓泡，添加和不添加四氢萘（一种环芳烃），以提高其沥青质含量并改变其形成碳纤维所需的物理化学性质。氧化后的HVGO样品的元素分析和理化表征表明，自氧化显著提高了沥青质含量，沥青质收率最高为47.2%，粘度为117.6 Pa。5，在190℃下，用5%四氢化萘和不混合的空气吹72小时，软化点达到210℃。它还发现，四氢化萘的添加维持有限的氧气条件，将有助于形成较重的产品，理想的碳纤维前体。通过扫描电镜成像分析，四氢化萘熔融纺丝得到直径为70µm的绿色纤维和直径为40 ~ 50µm的碳化纤维。氧化后的HVGO样品和碳纤维的质量残留物通过TGA分析得到了证实。所有这些观察结果表明，控制自氧化，特别是当添加四氢化萘时，是将低价值HVGO转化为高价值碳纤维前体的潜在途径。了解目前的研究还可以应用于生产用于碳纳米管，石墨烯和用于储能应用的碳材料的高价值碳材料。

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引用次数: 0

Advancing solar-assisted air gap membrane distillation through multi-short-channel module innovation 通过多短通道模块创新推进太阳能辅助气隙膜蒸馏

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-01-08 DOI: 10.1016/j.nexus.2026.100632

Kabbir Ali , Mohamed I Hassan Ali

This research analyzes the performance and economic viability of a solar-assisted air gap membrane distillation (AGMD) system, comparing a conventional single long-channel module with an optimized multi-short-channel configuration. A computational fluid dynamics (CFD) model, validated against published literature data (<5% error), was developed to evaluate the effects of Reynolds number, solar irradiance, air gap thickness, and concentration ratio (CR) on thermal and mass transfer characteristics. The multi-short-channel design consistently outperformed the single-channel module, achieving up to 26% higher permeate flux and marginally improved thermal efficiency due to reduced temperature polarization, enhanced flow uniformity, and sustained high membrane surface temperatures. Parametric analysis revealed that thinner air gaps and lower flow rates favored higher flux, whereas thicker gaps improved thermal efficiency, indicating a trade-off between productivity and energy utilization. Integration with a concentrator photovoltaic (CPV) solar absorber further elevated feedwater temperatures, with higher CR values significantly boosting system output. Economic analysis demonstrated that the multi-short-channel configuration reduced freshwater production costs by up to ∼25% compared to the single-channel design, reaching as low as (5–18) $/m³ under optimal solar and hydraulic conditions. These findings highlight the potential of advanced channel geometries and solar-thermal integration to deliver cost-effective, energy-efficient desalination solutions, particularly for remote and off-grid regions.

本研究分析了太阳能辅助气隙膜蒸馏（AGMD）系统的性能和经济可行性，比较了传统的单长通道模块和优化的多短通道配置。建立了计算流体动力学（CFD）模型，并对已发表的文献数据进行了验证（误差为5%），以评估雷诺数、太阳辐照度、气隙厚度和浓度比（CR）对传热和传质特性的影响。多短通道设计始终优于单通道模块，通过降低温度极化、增强流动均匀性和维持较高的膜表面温度，可实现高达26%的高渗透通量，并略微提高热效率。参数分析表明，更薄的气隙和更低的流量有利于更高的通量，而更厚的气隙提高了热效率，这表明了生产力和能量利用之间的权衡。与聚光光伏（CPV）太阳能吸收器的集成进一步提高了给水温度，更高的CR值显着提高了系统输出。经济分析表明，与单通道设计相比，多短通道配置可将淡水生产成本降低高达25%，在最佳太阳能和水力条件下可低至（5-18）美元/m³。这些发现强调了先进的通道几何形状和太阳能热集成的潜力，以提供具有成本效益，节能的海水淡化解决方案，特别是在偏远和离网地区。

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引用次数: 0

Obtaining the efficiency limits of axial hydrokinetic turbines 获得轴向水动力涡轮的效率极限

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-01-08 DOI: 10.1016/j.nexus.2026.100635

Víctor Manuel Fernández Pacheco , Ahmed Gharib Yosry , Rodolfo Espina Valdés , Alexandre Presas Batlló , Eduardo Álvarez Álvarez , Eduardo Blanco Marigorta

For a hydrokinetic turbine in an open field setting, in the absence of flow restrictions, Betz’s limit represents the maximum power coefficient possible. The efficiency of turbines is evaluated against this value, under the assumption that they are connected to the grid, and therefore continuously operating at their maximum power. However, in island model operation (disconnected to the mains) the turbines operate at points between the no load and the maximum power coefficient, being the efficiency limits different from the Betz’s limit. In the present study, a function has been found defining the power efficiency limits depending on the tip speed ratio, for axial turbines in an open channel without blockage. Mathematical deduction uses the actuator disk theory within an open channel, complemented by the Euler equation for turbomachinery. The approach assumes flow simplifications, including steady, one-dimensional, incompressible, and turbulent-free conditions. Furthermore, two dimensionless parameters have been proposed relating the real coefficient curve with the limit one. These parameters enable a better definition -in the whole range of tip speed ratios- of the difference between the actual efficiency and the limits, as well as the potential for improvement. Function and parameters have been calculated for a numerically simulated turbine and three different turbines from a literature benchmark.

对于开阔地设置的水动力涡轮，在没有流量限制的情况下，Betz极限表示可能的最大功率系数。涡轮机的效率是根据这个值来评估的，假设它们连接到电网，因此以最大功率持续运行。然而，在岛模型运行（与主电源断开）中，涡轮机在空载和最大功率系数之间的点上运行，这是与贝茨极限不同的效率限制。在目前的研究中，已经发现了一个函数定义功率效率限制取决于叶尖速比，轴向涡轮机在一个开放的通道没有堵塞。数学推导使用了在一个开放通道内的驱动器盘理论，并辅以涡轮机械的欧拉方程。该方法假定流动简化，包括稳定、一维、不可压缩和无湍流条件。此外，还提出了实系数曲线与极限系数曲线之间的两个无量纲参数。这些参数能够更好地定义在整个叶尖速比范围内的实际效率和极限之间的差异，以及改进的潜力。对数值模拟的水轮机和文献基准的三种不同的水轮机进行了功能和参数计算。

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引用次数: 0

Synthesizing a novel precipitant for lithium recovery from aqueous solutions via Williamson’s reaction 用Williamson反应合成一种从水溶液中回收锂的新型沉淀剂

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-10 DOI: 10.1016/j.nexus.2026.100665

Rabia Khatoon , Yeek-Chia Ho , Cecilia Devi Wilfred , Khairulazhar Jumbri , Dong Suk Han

The recovery of lithium from aqueous solutions presents significant opportunities for enhancing sustainable recovery methods in the oil and gas industries. This study focused on the synthesis of a novel precipitant, 2-(4-(3-ethylpentan-3-yl) phenoxy) acetic acid (PAAA), to improve lithium recovery. PAAA was synthesized via Williamson's reaction, with p‑tert-octyl phenoxyacetic acid (POAA) synthesized for comparative analysis. Optimization studies were conducted using Response Surface Methodology (RSM), targeting lithium recovery as the response variable. The results demonstrated that PAAA was successfully synthesized under optimal conditions: a pH of 12, a reaction time of 5 h, a temperature of 50 °C, and a molar dosage of amyl phenol of 0.06. The structures of PAAA and POAA were validated using NMR and FTIR spectroscopy, confirming C = O stretching frequencies at 1700 cm⁻¹ and 1730 cm⁻¹, respectively. Scanning Electron Microscopy (SEM) revealed that the rod-like shape of PAAA enhances lithium-ligand complex formation and precipitation. The study also examined various operating parameters for lithium recovery through the extraction-precipitation method, including reaction pH, reaction time, saponification rates, and molar ratios. A maximum lithium recovery of 84% was achieved under optimal conditions: pH 9, saponification at 85%, a reaction time of 40 min, and a molar ratio of PAAA to Li of 3. These findings highlight the potential of PAAA as an effective precipitant for lithium recovery in aqueous environments.

从水溶液中回收锂为提高油气行业的可持续回收方法提供了重要的机会。合成了一种新型沉淀剂2-（4-（3-乙基戊烷-3-基）苯氧基）乙酸（PAAA），以提高锂的回收率。采用Williamson反应合成PAAA，并与对叔辛基苯氧乙酸（POAA）进行对比分析。以锂回收率为响应变量，采用响应面法（RSM）进行优化研究。结果表明，在pH为12，反应时间为5 h，温度为50℃，戊基苯酚摩尔用量为0.06的条件下，成功合成了PAAA。PAAA和POAA的结构用NMR和FTIR光谱进行了验证，证实C = O的拉伸频率分别为1700 cm⁻¹和1730 cm⁻¹。扫描电镜（SEM）显示，PAAA的棒状结构促进了锂配体络合物的形成和沉淀。研究还考察了通过萃取-沉淀法回收锂的各种操作参数，包括反应pH、反应时间、皂化速率和摩尔比。在pH为9，皂化率为85%，反应时间为40 min， PAAA与Li的摩尔比为3的条件下，锂的最大回收率为84%。这些发现突出了PAAA作为水环境中锂回收的有效沉淀剂的潜力。

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引用次数: 0

Mitigating water evaporation and enhancing renewable energy with floating photovoltaic systems: An integrated approach to resource sustainability 通过浮动光伏系统减少水蒸发和增强可再生能源：资源可持续性的综合方法

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-10 DOI: 10.1016/j.nexus.2026.100683

Ali Mahmoudi Aznaveh, Hossein Yousefi, Fatemeh Razi Astaraei

Floating Photovoltaic (FPV) systems offer a new solution for managing water resources and producing sustainable energy. This study evaluates the impact of FPV technology on reducing water evaporation at five key dams supplying Tehran and nearby areas. Analysis of evaporation data and climatic conditions in the region from 1994 to 2023 showed that the cumulative evaporation during this period reached 2356.37 millimeters, and the SPEI index confirms a trend of increasing drought during this time. Using the FAO Penman-Monteith method, the 2023 evaporation rates were calculated, showing Taleghan Dam with the highest evaporation loss at 19,591,093 cubic meters and Mamlu Dam with the lowest at 7117,110 cubic meters. The study explored FPV deployment at 5%, 10%, and 20% coverage for each dam. Estimates indicate that with 80 percent FPV efficiency, evaporation reduction could be significant, with Taleghan Dam’s losses decreasing to 16,456,518 cubic meters and Mamlu Dam’s losses decreasing to 5978,372 cubic meters under 20 percent coverage. Furthermore, the potential for electricity generation was assessed, revealing that 10 percent FPV coverage of Latyan and Amir Kabir Dams could generate 72,064 MWh and 80,180 MWh of energy, respectively, while reducing CO₂ emissions by over 44,000 tons at each site. The economic analysis shows that FPV systems improve environmental sustainability by cutting evaporation and greenhouse gas emissions, while also supporting the economic feasibility of water and energy projects. This study underscores the importance of FPV technology in promoting integrated water conservation and renewable energy solutions amid climate change.

浮动光伏（FPV）系统为水资源管理和可持续能源生产提供了一种新的解决方案。本研究评估了FPV技术对减少德黑兰及附近地区五座主要水坝的水蒸发的影响。对1994 - 2023年的蒸发量资料和气候条件分析表明，该时期的累计蒸发量达到2356.37 mm， SPEI指数证实了该时期干旱加剧的趋势。采用FAO Penman-Monteith方法计算2023年的蒸发率，结果显示塔勒甘大坝蒸发损失最高，为19,591,093立方米，马姆卢大坝蒸发损失最低，为7,117,110立方米。该研究探讨了每个大坝在5%、10%和20%覆盖率下的FPV部署。估计表明，在80%的FPV效率下，蒸发减少可能会显着减少，在20%的覆盖率下，塔勒甘大坝的损失减少到16,456,518立方米，马姆卢大坝的损失减少到5978,372立方米。此外，对发电潜力进行了评估，结果显示，Latyan和Amir Kabir大坝10%的FPV覆盖率可以分别产生72,064兆瓦时和80,180兆瓦时的能源，同时每个站点减少超过44,000吨的二氧化碳排放。经济分析表明，FPV系统通过减少蒸发和温室气体排放来提高环境可持续性，同时还支持水和能源项目的经济可行性。这项研究强调了FPV技术在气候变化中促进综合节水和可再生能源解决方案的重要性。

{"title":"Mitigating water evaporation and enhancing renewable energy with floating photovoltaic systems: An integrated approach to resource sustainability","authors":"Ali Mahmoudi Aznaveh, Hossein Yousefi, Fatemeh Razi Astaraei","doi":"10.1016/j.nexus.2026.100683","DOIUrl":"10.1016/j.nexus.2026.100683","url":null,"abstract":"<div><div>Floating Photovoltaic (FPV) systems offer a new solution for managing water resources and producing sustainable energy. This study evaluates the impact of FPV technology on reducing water evaporation at five key dams supplying Tehran and nearby areas. Analysis of evaporation data and climatic conditions in the region from 1994 to 2023 showed that the cumulative evaporation during this period reached 2356.37 millimeters, and the SPEI index confirms a trend of increasing drought during this time. Using the FAO Penman-Monteith method, the 2023 evaporation rates were calculated, showing Taleghan Dam with the highest evaporation loss at 19,591,093 cubic meters and Mamlu Dam with the lowest at 7117,110 cubic meters. The study explored FPV deployment at 5%, 10%, and 20% coverage for each dam. Estimates indicate that with 80 percent FPV efficiency, evaporation reduction could be significant, with Taleghan Dam’s losses decreasing to 16,456,518 cubic meters and Mamlu Dam’s losses decreasing to 5978,372 cubic meters under 20 percent coverage. Furthermore, the potential for electricity generation was assessed, revealing that 10 percent FPV coverage of Latyan and Amir Kabir Dams could generate 72,064 MWh and 80,180 MWh of energy, respectively, while reducing CO<sub>2</sub> emissions by over 44,000 tons at each site. The economic analysis shows that FPV systems improve environmental sustainability by cutting evaporation and greenhouse gas emissions, while also supporting the economic feasibility of water and energy projects. This study underscores the importance of FPV technology in promoting integrated water conservation and renewable energy solutions amid climate change.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"21 ","pages":"Article 100683"},"PeriodicalIF":9.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Catalytic co-pyrolysis of teak wood sawdust and polystyrene: Effect of process parameters on yield and properties of pyrolysis oil 柚木木屑与聚苯乙烯催化共热解：工艺参数对热解油收率及性能的影响

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-09 DOI: 10.1016/j.nexus.2026.100668

Tanushka Florence Panicker, Ranjeet Kumar Mishra

The present study explores the thermo-catalytic co-pyrolysis of waste teak wood sawdust (TWS) and polystyrene (PS) using a semi-batch reactor. The experiments were performed at varying temperatures (450-550 °C), biomass-to-plastic ratios (10-50 wt.%), and catalyst loadings (5-20 wt.% of CaO and MgO). The physicochemical analysis of TWS and PS revealed HHV values of 19.50 and 43.18 MJ kg^-1, and oxygen contents of 45.40% and 0.43%, respectively. TGA results showed major biomass degradation occurring between 150-550 °C, while the FTIR analysis identified key functional groups, including C-H, C=C, -OH, and C=O. Thermal pyrolysis at 500 °C produced a 46.05% liquid yield, while the addition of 30 wt.% PS increased yield by 5.53%. The resultant pyrolytic oil exhibited an improved carbon content (81.37%) and a higher heating value (37.85 MJ kg^-1). The GC-MS analysis demonstrated a 59.69% increase in hydrocarbon yield at 30 wt.% PS while acids and ketones reduced by 4.58% and 9.74%, respectively. The addition of CaO (5 wt.%) and MgO (10 wt.%) enhanced the deoxygenation, aromatisation, and cracking reactions, resulting in selectivity towards aromatic hydrocarbons. The catalytic pyrolytic oil yielded 62% total hydrocarbons, with the aromatic fraction accounting for 56% of the total hydrocarbons. The NMR study further confirmed the shifting of the hydrogen from oxygen-containing compounds towards aromatic structures. Furthermore, blending PS at a dynamic ratio decreased the char yield, whereas adding catalysts increased it. The catalytic char showed increased ash content and demonstrated alkaline pH. Overall, the thermo-catalytic co-pyrolysis has significant potential to contribute to the circular economy by converting waste into renewable fuels and chemicals.

采用半间歇反应器对废柚木锯末（TWS）和聚苯乙烯（PS）的热催化共热解进行了研究。实验在不同温度（450-550°C）、生物质/塑料比（10-50 wt.%）和催化剂负载（5-20 wt.%的CaO和MgO）下进行。经理化分析，TWS和PS的HHV值分别为19.50和43.18 MJ kg-1，含氧量分别为45.40%和0.43%。TGA结果表明，主要的生物量降解发生在150-550°C之间，而FTIR分析发现了关键的官能团，包括C- h， C=C， -OH和C=O。500℃热热解产液率为46.05%，添加30 wt.% PS可使产液率提高5.53%。所得热解油的含碳量提高了81.37%，热值提高了37.85 MJ kg-1。GC-MS分析表明，在30 wt.% PS时，烃收率提高了59.69%，而酸和酮的收率分别降低了4.58%和9.74%。CaO （5 wt.%）和MgO （10 wt.%）的加入增强了脱氧、芳香化和裂化反应，对芳香烃有选择性。催化裂解油的总烃收率为62%，其中芳烃馏分占总烃的56%。核磁共振进一步证实了氢从含氧化合物向芳香结构的转移。此外，以动态比掺合PS降低了炭产率，而添加催化剂则提高了炭产率。催化炭的灰分含量增加，ph值呈碱性。总的来说，热催化共热解通过将废物转化为可再生燃料和化学品，对循环经济有很大的贡献。

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引用次数: 0

Upcycling autoclaved aerated concrete into sustainable and energy-efficient geopolymers with improved structural attributes 将蒸压加气混凝土升级为具有改进结构属性的可持续节能地聚合物

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-09 DOI: 10.1016/j.nexus.2026.100685

Mohammad Reza Hanafi , Hamed Rahimpour , Zohre Babai Golsefidi , Sahar Zinatloo-Ajabshir , Somayeh Mollaei , Faramarz Moodi , Hamid Zarrabi , Ahmad Fahmi

This study aims to achieve the complete recycling of post-demolition autoclaved aerated concrete (AAC) and to develop sustainable, energy-efficient, and high-performance geopolymer construction materials. Recycled AAC powder with different particle sizes was used as the aluminosilicate precursor and mixed with alkaline activators consisting of water glass and sodium hydroxide at concentrations of 4, 8, 12, and 16 mol. The effects of alkaline concentration, activator ratio, curing temperature, and precursor particle size on the mechanical properties and bulk density of the synthesized geopolymer materials were systematically evaluated. Increasing sodium hydroxide concentration and the water glass-to-sodium hydroxide ratio enhanced mechanical strength, while higher curing temperatures decreased bulk density. Under optimal conditions (12 molar sodium hydroxide, activator ratio of 2, curing at 85 °C, and a particle size of 150 µm), the compressive, tensile, and flexural strengths reached 27.03, 3.51, and 2.73 MPa, respectively. Water absorption after 24 h was measured at 11.9 wt.%, and chemical/microstructural analyses revealed a dense and homogeneous matrix consistent with complete geopolymerization. A life cycle assessment demonstrated an 86% reduction in climate-change impact, along with lower resource consumption, water use, and toxicity compared to ordinary Portland cement, confirming the environmental advantages of the proposed approach. Overall, the findings demonstrate that post-demolition AAC can be fully upcycled into structurally efficient and environmentally responsible geopolymer materials, with strong potential for application in sustainable construction products including high-performance precast elements and masonry units.

本研究旨在实现拆除后蒸压加气混凝土（AAC）的完全回收利用，开发可持续、节能、高性能的地聚合物建筑材料。采用不同粒径的再生AAC粉末作为硅酸铝前驱体，与水玻璃和氢氧化钠组成的碱性活化剂混合，浓度分别为4、8、12和16 mol。系统评价了碱浓度、活化剂配比、固化温度和前驱体粒径对合成地聚合物材料力学性能和堆积密度的影响。增加氢氧化钠的浓度和水玻璃与氢氧化钠的比例可以提高材料的机械强度，而提高固化温度则会降低材料的体积密度。在最佳条件下（12摩尔氢氧化钠，活化剂比为2,85℃固化，粒径为150µm），抗压、抗拉和抗折强度分别达到27.03、3.51和2.73 MPa。24小时后的吸水率为11.9 wt.%，化学/微观结构分析显示基质致密均匀，与完全地聚合一致。一项生命周期评估表明，与普通波特兰水泥相比，该水泥对气候变化的影响减少了86%，同时资源消耗、用水量和毒性也更低，证实了该方法的环境优势。总体而言，研究结果表明，拆除后的AAC可以完全升级为结构高效且对环境负责的地聚合物材料，在可持续建筑产品（包括高性能预制件和砌体单元）中具有强大的应用潜力。

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引用次数: 0

Shifting from mid-season and double-season rice to ratoon rice improves the sustainability of rice production systems 从季中稻和双季稻转向再生稻，提高了水稻生产系统的可持续性

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-10 DOI: 10.1016/j.nexus.2026.100684

Shuang Cheng, Yalan Ji, Zhong Li, Youzun Xu, Yongjin Zhou

The rising demand for food, climate change, energy shortages, and increasing production costs have exerted tremendous pressure on rice production in China. Exploring suitable rice cropping systems is crucial for promoting sustainable rice production. This study comprehensively compared three major rice cropping systems: middle-season rice (MR), ratoon rice (RR), and double-season rice (DR), focusing on grain yield, net ecosystem economic budget (NEEB), environmental benefits, and energy efficiency. The results indicated that the annual average yield of RR was 13.1 t ha⁻¹, which was 10.4%–12.4% lower than that of DR but 36.3%–36.6% higher than that of MR. The lower annual yield of RR relative to DR was mainly attributable to its lower ratoon season yield compared to the late rice yield in DR. Further increasing the ratoon season yield is key for RR to exceed the yield of DR. The global warming potential (GWP) of the three rice cropping systems ranged from 12,334.4 to 18,421.4 kg CO₂ -eq·ha⁻¹. Compared with DR, the GWP of RR and MR decreased by 21.7% and 33.0%, respectively. RR achieved the highest NEEB (13,708.7 CNY·ha⁻¹), which was 25.0%-28.6% higher than DR and 18.2%-25.7% higher than MR, respectively. This superior performance was mainly attributed to RR's significantly high economic benefit, as well as its moderate ecological costs, by improving resource production efficiency. Furthermore, RR exhibited the highest energy use efficiency (3.4), exceeding MR by 6.3% and DR by 47.8%, primarily due to its superior energy output relative to MR (1926,435 MJ ha⁻¹ vs 1411,935 MJ ha⁻¹) and reduced energy inputs compared to DR (57,140 MJ ha⁻¹ vs 95,474 MJ ha⁻¹). These results demonstrate that RR represents a sustainable rice cropping system capable of balancing grain yield, NEEB, environmental benefits, and energy efficiency. This system is suitable for promotion in southern China where thermal resources are insufficient for DR but surplus for MR, as well as in regions transitioning from DR to MR, thereby enhancing the sustainability of rice production in China. Adopting high-ratooning varieties and optimizing cultivation techniques during the ratoon season may further enhance the overall performance of this system.

粮食需求上升、气候变化、能源短缺、生产成本上升等因素给中国水稻生产带来巨大压力。探索合适的水稻种植制度对促进可持续的水稻生产至关重要。本研究综合比较了三种主要的水稻种植制度：中稻（MR）、冬稻（RR）和双季稻（DR），重点研究了粮食产量、净生态系统经济预算（NEEB）、环境效益和能源效率。结果表明，红豆杉年平均产量为13.1 tha（⁻¹）；10.4%低于-12.4%但36.3% - -36.6%高于博士先生的下年度的RR收益率相对于博士主要是归因于低截根苗季产量相比,晚稻产量博士进一步增加截根苗季节是关键的RR收益率的收益率超过全球变暖潜力博士(GWP)三个水稻种植制度的范围从12334到18421。4公斤二氧化碳eq·公顷⁻¹。与DR相比，RR和MR的GWP分别下降了21.7%和33.0%。RR达到了最高的NEEB （13,708.7 CNY·ha⁻），比DR高25.0%-28.6%，比MR高18.2%-25.7%。这种优越的表现主要是由于RR通过提高资源生产效率，具有显著的高经济效益和适度的生态成本。此外，右下角显示出最高的能量使用效率（3.4），比右下角高6.3%，比右下角高47.8%，这主要是由于右下角的能量输出比右下角高（1926年，435 MJ ha⁻¹vs 1411,935 MJ ha⁻¹），右下角的能量输入比右下角低（57,140 MJ ha⁻¹vs 95,474 MJ ha⁻¹）。这些结果表明，RR代表了一种能够平衡粮食产量、NEEB、环境效益和能源效率的可持续水稻种植系统。该系统适合在中国南方热资源不足、热资源过剩的地区推广，以及从热资源过剩向热资源过剩过渡的地区推广，从而提高中国水稻生产的可持续性。在再生季节采用高再生品种和优化栽培技术可进一步提高该体系的整体性能。

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引用次数: 0

Hybrid Renewable Microgrid Optimization for Cost Reduction, Emission Mitigation, and Net-Metering Grid-Connected Stability in University Student Residences for Developing Countries 面向发展中国家大学生住宅的混合可再生微电网优化：降低成本、减少排放和净计量并网稳定性

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-09 DOI: 10.1016/j.nexus.2026.100649

Md. Feroz Ali , Md. Mahadi Hasan Rony , Diganto Biswas , Md. Esmay Azam , Sk․ A. Shezan , Innocent Kamwa

The increasing energy demand of institutional facilities, coupled with rising electricity costs and emission concerns, necessitates the development of efficient and sustainable hybrid renewable energy systems. Although numerous studies have investigated hybrid microgrids, limited attention has been given to campus-scale systems that integrate multiple renewable sources with grid-connected net-metering and practical operational considerations. This study aims to design and optimize a grid-connected hybrid renewable microgrid for a university student residence using real load data. The proposed system integrates photovoltaic, wind, biomass-based generation, battery energy storage, and utility grid support, and is analyzed using HOMER Pro to evaluate techno-economic performance, renewable penetration, and emission reduction. The optimized configuration achieves a daily energy demand of 390.56 kWh with a peak load of 53.4 kW, resulting in a significantly reduced net present cost and cost of energy, along with substantial reductions in greenhouse gas emissions compared to the base case. Sensitivity and comparative analyses further demonstrate the robustness of the proposed system under varying resource and economic conditions. The findings confirm that multi-source hybrid microgrids with net-metering can provide a cost-effective and environmentally sustainable energy solution for campus-scale applications.

机构设施的能源需求不断增加，加上电力成本上升和排放问题，必须发展有效和可持续的混合可再生能源系统。尽管有许多研究对混合微电网进行了调查，但对将多种可再生能源与并网的净计量和实际操作考虑相结合的校园规模系统的关注有限。本研究旨在利用实际负荷数据，为大学生住宅设计并优化并网混合可再生微电网。该系统集成了光伏、风能、生物质发电、电池储能和公用电网支持，并使用HOMER Pro对技术经济性能、可再生能源渗透率和减排进行了分析。优化后的配置实现了每日能源需求390.56千瓦时，峰值负荷为53.4千瓦，与基本情况相比，显著降低了净当前成本和能源成本，同时大幅减少了温室气体排放。敏感性和比较分析进一步证明了该系统在不同资源和经济条件下的鲁棒性。研究结果证实，具有净计量的多源混合微电网可以为校园规模的应用提供成本效益和环境可持续的能源解决方案。

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引用次数: 0

Modeling power and workforce demand in French field agriculture highlights variability, fleet redundancy, and magnitude comparable to renewable electricity generation 法国田间农业的电力和劳动力需求建模突出了可变性、机队冗余和可再生能源发电的规模

IF 9.5 Q1 ENERGY & FUELS

Energy nexus

Pub Date : 2026-03-01 Epub Date: 2026-02-09 DOI: 10.1016/j.nexus.2026.100654

Cyprien Drommi, Petros Chatzimpiros

Mechanized agriculture relies heavily on fossil fuels for field operations, while facing decarbonization and environmental sustainability challenges. Phasing out fossil fuels requires alternative energy supply that can provide sufficient power to perform field tasks. However, the variability of agricultural power demand remains unexplored, yet it is crucial for anticipating energy transition to renewable flows. Here, we fill this gap by modeling on-field power demand distribution over a full cropping season based on production practices from public surveys and using national-scale French agriculture as a case study. Results show high variability in power demand, ranging from below 5 to above 12 GW during autumn tillage. Compared to total installed engine power, the load factor of tractors and combine-harvesters peaks at about 18 % and 23 % respectively. This indicates substantial fleet redundancy, which is in part necessary to accommodate unpredictability in field working conditions. By assessing scenarios of agroecological practices, we show that no-till practices help reduce peak power demand, whereas organic practices result in a marginal power demand increase. In parallel, we assess workforce requirement for field driving of machinery. This requirement peaks simultaneously with power demand at one-third of total workers and accounts for 12 % of annual working time in agriculture. Our findings highlight trade-offs between farming system organization, practices and on-field power demand, revealing that the latter is currently comparable in scale to renewable (wind and solar) power generation in France. The results underscore the need to integrate power demand analysis of fossil-fueled activities into energy transition policies and planning.

机械化农业严重依赖化石燃料进行田间作业，同时面临着脱碳和环境可持续性的挑战。逐步淘汰化石燃料需要替代能源供应，以提供足够的电力来执行现场任务。然而，农业电力需求的可变性仍未得到探索，但它对于预测能源向可再生能源的过渡至关重要。在这里，我们根据公众调查的生产实践，并以法国全国范围的农业为例，通过对整个种植季节的田间电力需求分布进行建模，填补了这一空白。结果表明，秋耕期间的电力需求变化很大，从低于5吉瓦到高于12吉瓦不等。与总装发动机功率相比，拖拉机和联合收割机的负载系数峰值分别约为18%和23%。这表明大量的船队冗余，这在一定程度上是为了适应现场工作条件的不可预测性。通过评估农业生态实践的情景，我们发现免耕实践有助于降低峰值电力需求，而有机实践导致边际电力需求增加。同时，我们评估了机械现场驾驶的劳动力需求。这一需求与电力需求同时达到峰值，占总工人的三分之一，占农业年工作时间的12%。我们的研究结果强调了农业系统组织、实践和现场电力需求之间的权衡，揭示了后者目前在规模上与法国的可再生能源（风能和太阳能）发电相当。研究结果强调了将化石燃料活动的电力需求分析纳入能源转型政策和规划的必要性。

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引用次数: 0