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Energy, exergy & economic analysis of producing hydrogen in a PVT-ORC-PEMEC system PVT-ORC-PEMEC制氢系统的能源、能源和经济分析

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138399

Mohammad Kazem Tabatabaeizadeh, Majid Ghassemi

The reliance on fossil fuels results in environmental degradation and poses significant risks to human health. Furthermore, these resources are finite, prompting the global community to seek sustainable and clean energy sources. Renewable energy presents a viable solution to this challenge. This study aims to present a highly reliable design for producing clean fuel from renewable sources. The governing equations of our study are rooted in thermodynamic principles. The methodology involves the numerical simulation of a photovoltaic thermal cell (PVT) using ANSYS Fluent software, with the output being the fluid temperature of the photovoltaic thermal cell pipes. The software results serve as input data for a Python script, which calculates the annual hydrogen production for the city of Yazd. According to our calculations, the standalone electrical efficiency of the PVT averaged 22.18 % annually. By integrating the PVT with the Rankine cycle, electrical efficiency improved by a maximum of 6 %, leading to an average annual hydrogen production of 15.74 mol per hour for each unit of a proton exchange membrane electrolyzer cell (PEMEC). The average overall exergy efficiency of this combined system is approximately 32.26 %. The economic analysis indicates that the payback period for this system is estimated to be 5.37 years.

对化石燃料的依赖导致环境退化，并对人类健康构成重大风险。此外，这些资源是有限的，促使国际社会寻求可持续和清洁的能源。可再生能源为这一挑战提供了一个可行的解决方案。这项研究旨在提出一种高度可靠的设计，用于从可再生能源中生产清洁燃料。我们研究的控制方程植根于热力学原理。该方法采用ANSYS Fluent软件对光伏热电池（PVT）进行数值模拟，输出为光伏热电池管道的流体温度。软件结果作为Python脚本的输入数据，该脚本计算亚兹德市每年的氢气产量。根据我们的计算，PVT的独立电效率平均每年为22.18%。通过将PVT与Rankine循环相结合，电效率提高了6%，使质子交换膜电解槽（PEMEC）的每个单元的年平均产氢量达到15.74 mol / h。该联合系统的平均总火用效率约为32.26%。经济分析表明，该系统的投资回收期为5.37年。

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引用次数: 0

Experimental and kinetic modeling insights into combustion characteristics of methane jet flames: role of equivalence ratio in spatiotemporal radical dynamics and heat release 甲烷喷射火焰燃烧特性的实验和动力学建模：等效比在时空自由基动力学和热释放中的作用

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138554

Jun Deng, Xing Li, Yaqing Li, Yutao Zhang, Yuanbo Zhang, Qiang Guo, Xiaodi Zhang

The macroscopic evolution and radical mechanisms of methane jet flames were investigated through experimental and kinetic analyses. The findings indicate that the equivalence ratio has a significant impact on the macroscopic characteristics of the flame. Specifically, at the nozzle, incomplete combustion results in reduced heat release, with the temperature peak occurring in the well-mixed region. As the flow velocity increases, the heat flux initially rises before subsequently declining. When the equivalence ratio approaches 1, combustion becomes more complete, leading to a notable increase in both the ion current of the flame and the adiabatic flame temperature. Kinetic analysis reveals that the concentrations of reactive radicals initially rise and then fall over time, with the peak concentration occurring later. Reactions R₁₀ and R₈₄ exhibit the fastest heat release over time, while R₁₀ and R₅₂ release the most heat spatially; R₃₈ demonstrates the strongest endothermic reaction across both temporal and spatial scales, with its heat release rate peaking at an equivalence ratio of 1.0. Sensitivity analysis elucidates the spatiotemporal evolution of key radicals such as H, O, OH, and CH₃: on the temporal scale, OH and H primarily drive early heat release through chain reactions; on the spatial scale, H influences a broader area due to its strong diffusion capability, OH is rapidly consumed near its generation site, and CH₃ primarily affects heat release indirectly through subsequent oxidation.The rapid consumption and efficient diffusion of OH and H radicals create a synergistic heat release mechanism. The spatiotemporal distribution characteristics of these radicals offer crucial insights for enhancing methane burner design and bolstering combustion stability.

通过实验和动力学分析，研究了甲烷射流火焰的宏观演化和根治机理。结果表明，等效比对火焰的宏观特性有显著影响。具体来说，在喷嘴处，不完全燃烧导致热量释放减少，温度峰值出现在混合良好的区域。随着流速的增大，热流密度先上升后下降。当等效比接近1时，燃烧更加完全，导致火焰的离子流和绝热火焰温度都有显著的增加。动力学分析表明，随着时间的推移，活性自由基的浓度开始上升，然后下降，峰值浓度出现较晚。反应R10和R84在时间上释放热量最快，而R10和R52在空间上释放热量最多；R38的吸热反应在时间和空间尺度上都表现出最强的吸热反应，其放热率在等效比为1.0时达到峰值。敏感性分析揭示了关键自由基H、O、OH和CH3的时空演化：在时间尺度上，OH和H主要通过链式反应驱动早期热释放；在空间尺度上，H因其强大的扩散能力影响范围更广，OH在其生成位点附近被迅速消耗，CH3主要通过随后的氧化间接影响热释放。OH和H自由基的快速消耗和有效扩散形成了协同放热机制。这些自由基的时空分布特征为改进甲烷燃烧器设计和增强燃烧稳定性提供了重要的见解。

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引用次数: 0

Synergistic and antagonistic interaction effects during the co-gasification of polyethylene and polystyrene in supercritical water 聚乙烯和聚苯乙烯在超临界水中共气化过程中的协同和拮抗相互作用

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138524

Hengda Han , Saumitra Saxena , Ribhu Gautam , Mengyan Wang , Fabiyan Angikath , Frederick L. Dryer , Bassam Dally

The co-gasification of polyethylene (PE) and polystyrene (PS) in a non-catalytic supercritical water was experimentally investigated to evaluate synergistic and antagonistic effects on gasification performance. Using a quartz tube-based batch reactor, the effects of temperature, residence time and varying PE: PS blending ratio were systematically studied. PE showed high carbon conversion efficiency, while PS exhibited lower reactivity but produced hydrogen-rich syngas. Co-gasification of PE–PS mixtures slightly inhibits the conversion efficiency at high PE blending ratios. This is attributed to the formation of a tar-derived condensation layer on the char surface, which acts as a physical barrier and suppresses gasification reactions. At high PS proportions, the conversion efficiency is markedly enhanced (up to 57% during the initial stage at 700 °C). At a residence time of 30 min, the layer on the char surface can be consumed. PE–PS mixtures generate almost the same or even more gas than that from individual gasification. Comparison between the model analysis and experimental results suggests that in addition to radical-mediated interactions, surface reactions might be responsible for the synergistic effects associated with defects on the char surface. By optimizing the plastic ratio, the mixture can achieve a comparable hydrogen conversion at 600 °C, which is approximately equal to that at 700 °C. This represents a 39% improvement arising from synergistic interactions which is possibly attributed to the enhanced mass transfer from CO₂ dissolution. This study offers valuable guidance for the development of efficient and sustainable supercritical water gasification strategies for plastic waste valorization.

实验研究了聚乙烯（PE）和聚苯乙烯（PS）在非催化超临界水中的共气化，以评价其对气化性能的增效和拮抗作用。采用石英管间歇式反应器，系统研究了温度、停留时间和PE: PS掺混比的影响。PE具有较高的碳转化效率，而PS反应性较低，但产生富氢合成气。PE - ps共气化对高PE掺比下的转化效率有轻微的抑制作用。这是由于在焦炭表面形成了焦油衍生的冷凝层，它作为物理屏障，抑制了气化反应。在高PS比例下，转换效率显著提高（在700°C的初始阶段高达57%）。在30分钟的停留时间内，可以消耗炭表面的层。PE-PS混合物产生的气体几乎与单独气化产生的气体相同，甚至更多。模型分析与实验结果的对比表明，除了自由基介导的相互作用外，表面反应可能是与炭表面缺陷相关的协同效应的原因。通过优化塑性比，混合物在600℃时的氢转化率与700℃时的氢转化率大致相当。这意味着39%的改进来自于协同作用，这可能归因于CO2溶解的传质增强。该研究为开发高效、可持续的超临界水气化塑料垃圾处理策略提供了有价值的指导。

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引用次数: 0

Insight into the mechanism of hydrogen transfer and exchange in direct liquefaction of Shangwan coal using isotope-tracer method 用同位素示踪法研究上湾煤直接液化过程中氢转移交换机理

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138547

Rui Zhang , Lijun Jin , Jianli Wang , Haoquan Hu

Elucidation of the hydrogen transfer mechanism between H₂, solvent, and coal is of great significance for improving the direct coal liquefaction (DCL) efficiency. To better understand the hydrogen transfer mechanism during the DCL, in this study, liquefaction of Shangwan coal was conducted under H₂ or D₂ and in the presence of Shenhua nanosized iron catalyst (SH-cat), NaFeS₂ or molybdenum-based (Mo-cat) catalyst. Higher oil and lower preasphaltene and asphaltene (PAA) yields under H₂ than those under D₂ indicate a kinetic isotope effect in DCL, implying that hydrocracking of the intermediate PAA is part of the rate-determining step in DCL. Further, the deuterium content in the solvent after reaction was determined, and the deuterium balance among the DCL products, donor solvent, and gas phase hydrogen was established by using the mass cluster method developed in this study. The results showed that on average 30% of deuterium incorporated into the solvent and DCL products resulted from hydrogen transfer, and the remaining 70% was incorporated into the solvent and products by hydrogen exchange. In addition, the ²H NMR results of the solvent after reaction with and without coal indicated that the hydrogen exchange exhibits high selectivity for α-aliphatic positions in tetralin, while the hydrogen transfer results in a more homogeneous deuterium distribution across both α- and β-positions. Eventually, a reaction scheme of hydrogen transfer and exchange was proposed to determine the contribution of the hydrogen-shuttling role of the solvent to DCL. The ratio of H₂ transferred to coal through solvent under different catalysts was found to increase in the following order: Mo-cat < SH-cat < NaFeS₂, which is contrary to the order of hydrogen activation capability of each catalyst. In other words, the catalyst with higher activity for hydrogen activation facilitates direct hydrogen transfer to coal, reducing reliance on the solvent as a transfer medium.

阐明H2、溶剂和煤之间的氢转移机理对提高煤直接液化效率具有重要意义。为了更好地了解DCL过程中的氢转移机理，本研究在H2或D2条件下，在神华纳米铁催化剂（SH-cat）、NaFeS2或钼基催化剂（Mo-cat）的存在下，对上湾煤进行了液化。H2条件下的原油产率高于D2条件下的原油产率，而前沥青烯和沥青烯（PAA）产率低于D2条件下的产率，这表明在DCL中存在动力学同位素效应，表明中间PAA的加氢裂化是DCL中速率决定步骤的一部分。进一步测定了反应后溶剂中的氘含量，并利用本研究开发的质量团簇法建立了DCL产物、供体溶剂和气相氢之间的氘平衡。结果表明，平均30%的氘通过氢转移进入溶剂和DCL产物，其余70%通过氢交换进入溶剂和产物。此外，与煤反应和不与煤反应后溶剂的2H NMR结果表明，氢交换对四氢萘中α-脂肪族位置具有较高的选择性，而氢转移导致氘在α-和β-位置上的分布更为均匀。最后，提出了一种氢转移交换反应方案，以确定溶剂对DCL的穿梭作用。不同催化剂下H2通过溶剂转移到煤中的比例增加的顺序为：Mo-cat <； SH-cat < NaFeS2，这与各催化剂的氢活化能力顺序相反。换句话说，具有较高氢活化活性的催化剂有利于氢直接转移到煤中，减少了对溶剂作为转移介质的依赖。

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引用次数: 0

Study on the mechanism of shale fragmentation induced by laser irradiation under submerged conditions 水下条件下激光照射诱导页岩破碎机理研究

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138525

Haizeng Pan , Yi Hu , Feng Liu , Hejuan Liu , Yong Kang , Lian Li

Laser technology, recognized for its high energy density and precise directivity, presents an innovative approach to rock breaking in the oil and gas industry. This study investigates laser-induced rock breaking under submerged conditions, with a focus on the influence of water layer thickness and irradiation parameters, including power, duration, and target distance. The laser rock breaking process comprises four distinct stages: energy absorption, sample melting, evaporation, and sputtering. During irradiation, the surface temperature of the rock rises sharply, inducing intense thermal destruction and vaporization in the central region and resulting in a V-shaped hole. Thicker water layers lead to higher laser energy attenuation, which reduces rock damage and crack development. As a consequence, both the hole area and diameter decrease, lowering drilling efficiency and rock removal capacity, while increasing the specific energy from 6.61 to 30.31 kJ/cm³. Under submerged conditions, higher laser power enhances energy absorption, expands the melting and thermal affected zones, and increases hole depth and mass loss. These effects collectively improve the drilling rate and reduce specific energy, thereby significantly boosting process efficiency. Extending irradiation time enlarges hole dimensions, but the rate of penetration (ROP) peaks at 6 s. The optimal target distance is identified as 4 cm. Microscopic observations reveal that the laser-affected sample surface can be divided into three characteristic zones: the hole zone, the melting zone, and the thermal effect zone. Additionally, molten rock resolidifies on the hole wall, forming a dense vitrified layer. These findings establish an experimental basis for the practical application of laser technology in rock breaking.

激光技术以其高能量密度和精确的指向性而闻名，为油气行业提供了一种创新的破岩方法。本研究研究了水下条件下的激光破岩，重点研究了水层厚度和辐照参数（包括功率、持续时间和目标距离）对激光破岩的影响。激光破岩过程包括四个不同的阶段：能量吸收、样品熔化、蒸发和溅射。在辐照过程中，岩石表面温度急剧上升，在中部区域引起强烈的热破坏和汽化，形成v形孔。较厚的水层导致较高的激光能量衰减，从而减少岩石损伤和裂缝的发展。因此，钻孔面积和直径减小，钻井效率和岩石清除能力降低，而比能量从6.61 kJ/cm3增加到30.31 kJ/cm3。在水下条件下，较高的激光功率增强了能量吸收，扩大了熔化区和热影响区，增加了孔深和质量损失。这些效果共同提高了钻井速度，降低了比能量，从而显著提高了工艺效率。延长辐照时间使孔尺寸增大，但穿透速率（ROP）在6 s时达到峰值。确定最佳目标距离为4 cm。显微观察表明，激光影响的样品表面可分为三个特征区：空穴区、熔化区和热效应区。此外，熔融岩石在孔壁上重新凝固，形成致密的玻璃化层。这些研究结果为激光技术在破岩中的实际应用奠定了实验基础。

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引用次数: 0

Synergistic effects between Si, Cu and K promoters and their influences on the structures and performances of Fe-based Fischer–Tropsch synthesis catalysts Si、Cu和K促进子的协同效应及其对铁基费托合成催化剂结构和性能的影响

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138556

Xiaoming Suo , Zhengjia Li , Jie Cen , Meng Cheng , Quan Lin , Zhuowu Men , Weizhen Li , Nan Yao , Xiaonian Li

K, Cu and Si promoters were often used in the preparation of iron-based Fischer–Tropsch synthesis (FTS) catalysts, but their synergism and related effects on the structures and intrinsic reactivities of Fe-based catalysts were not clearly disclosed. In this work, in order to avoid marked structure change due to the different pretreatment and reaction condition, Fe-based catalysts with the combination of different Cu, Si and K promoters were prepared and tested directly under the reaction condition without reduction/carbonization pretreatment so that their FTS performance data could be well corelated to the structure properties disclosed by in situ characterization (XPS and XRD) and theoretical modeling. Without Si promoter, it revealed that small Fe₅C₂ (<9 nm) had lower turnover frequency (TOF) than large Fe₅C₂ particle, and both Cu and K promoters could not increase TOF values of small Fe₅C₂. Moreover, it appeared that the deactivation of Fe–Cu–K catalyst occurred due to the particle sintering, enrichment of Cu and deposition of less reactive carbon species. In contrast to Fe–Cu–K catalyst, the presence of Si promoter inhibited particle sintering and enrichment of Cu, reduced the deposition of less reactive carbon species in FTS reaction so that it delayed the deactivation of Fe–Cu–Si–K catalyst. Meanwhile, Si promoter prevented the oxidation of Cu⁰ species. The retaining Cu⁰ facilitated the electron transfer between K and Fe species. Such synergistic effect between Si, Cu and K promoters enabled to produce Fe⁰ species with higher electron cloud density on small Fe₅C₂ particles, thereby improving the TOF of small Fe₅C₂ in Fe–Cu–Si–K catalyst (∼ 41 h⁻¹) much higher than those (<11 h⁻¹) of other Fe-based catalysts.

K、Cu和Si促进剂常用于制备铁基费托合成（FTS）催化剂，但其协同作用及其对铁基催化剂结构和本构反应性的影响尚未明确。为了避免因不同的预处理和反应条件而导致明显的结构变化，本文制备了不同Cu、Si和K促进剂组合的fe基催化剂，并在不进行还原/碳化预处理的反应条件下直接进行了测试，使其FTS性能数据与原位表征（XPS和XRD）和理论建模所揭示的结构性能具有良好的相关性。在没有Si启动子的情况下，发现小颗粒Fe5C2 （<9 nm）的TOF比大颗粒Fe5C2的TOF要低，Cu和K启动子都不能提高小颗粒Fe5C2的TOF值。此外，Fe-Cu-K催化剂的失活似乎是由于颗粒烧结、Cu富集和活性碳较少的沉积所致。与Fe-Cu-K催化剂相比，Si促进剂的存在抑制了颗粒的烧结和Cu的富集，减少了FTS反应中活性碳较少的沉积，从而延缓了Fe-Cu-Si-K催化剂的失活。同时，Si促进剂阻止了Cu0的氧化。保留的Cu0促进了K和Fe之间的电子转移。Si、Cu和K之间的协同作用使得Fe5C2小颗粒上产生具有更高电子云密度的Fe0物质，从而提高了Fe-Cu-Si-K催化剂中Fe5C2小颗粒的TOF (~ 41 h−1)，远高于其他铁基催化剂的TOF （<11 h−1）。

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引用次数: 0

Porous NiFeP electrocatalyst prepared via a fully electrochemical strategy combining hydrogen bubble templating and surface modification for anion exchange membrane water electrolysis 采用氢泡模板和表面修饰相结合的全电化学策略制备了用于阴离子交换膜电解的多孔NiFeP电催化剂

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138401

Yeosol Yoon, Subin Choi, Jihyeon Ok, Taeho Lim

Water electrolysis is a key technology for green hydrogen production; however, the oxygen evolution reaction (OER) occurring at the anode remains the main kinetic bottleneck because of its sluggish multielectron transfer process. Thus, developing efficient and durable electrocatalysts is essential for increasing the commercial viability of anion exchange membrane water electrolysis (AEMWE). In this study, a porous NiFeP catalyst has been prepared via a fully electrochemical strategy that integrates dynamic hydrogen bubble template (DHBT) electrodeposition with KSCN-assisted surface modification. This strategy offers rapid, low-cost, and scalable fabrication as well as precise control over the catalyst morphology and surface chemistry. DHBT electrodeposition generates an interconnected microporous network with high surface area, while the subsequent KSCN treatment induces Ni leaching and reconstructs the surface into amorphous high-valent metal phases, thereby optimizing the electronic structure to increase the OER activity. The resulting catalyst demonstrates a large surface area and excellent catalytic performance, achieving an overpotential of 269 mV at 100 mA cm⁻² in a 1 M KOH solution. When employed as an anode for single-cell AEMWE, it reaches a current density of 1.0 A cm⁻² at 1.70 V with minimal performance degradation over 100 h. This facile and scalable synthesis route highlights a practical pathway for developing noble metal-free OER catalysts for sustainable hydrogen generation.

水电解是绿色制氢的关键技术；然而，发生在阳极的析氧反应（OER）由于其多电子转移过程缓慢而成为主要的动力学瓶颈。因此，开发高效、耐用的电催化剂对于提高阴离子交换膜电解（AEMWE）的商业可行性至关重要。在这项研究中，通过将动态氢泡模板（DHBT）电沉积与kscn辅助表面修饰相结合的全电化学策略制备了多孔NiFeP催化剂。该策略提供了快速，低成本和可扩展的制造以及对催化剂形态和表面化学的精确控制。DHBT电沉积形成了一个具有高表面积的互连微孔网络，而随后的KSCN处理诱导Ni浸出，并将表面重构为无定形高价金属相，从而优化电子结构，提高OER活性。所得催化剂具有较大的表面积和优异的催化性能，在1 M KOH溶液中，在100 mA cm−2下可达到269 mV的过电位。当用作单电池AEMWE阳极时，它在1.70 V下达到1.0 a cm - 2的电流密度，并且在100小时内性能下降最小。这种简单且可扩展的合成路线为开发用于可持续制氢的无贵金属OER催化剂提供了实用途径。

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引用次数: 0

Combustion performance, fluid behaviors, and reaction mechanism of a disk-type planar swirl micro-combustor with dual tangential inlets 双切向入口圆盘型平面旋流微燃烧室的燃烧性能、流体行为及反应机理

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138539

Yang Wang , Ben Yang , Lichao Ge , Heping Li , Iñigo Ortega-Fernández , Daniel Bielsa

This study proposes a planar swirl micro-combustor with dual tangential inlets, distinguished by its novel disk-type structure—a key departure from traditional cylindrical micro-combustors—to enhance combustion stability and thermal efficiency in micro-scale energy systems. The combustor features a compact circular chamber (10 mm diameter, 0.5 mm height), where hydrogen/air mixtures generate a swirling flow, improving reactant mixing, extending residence time, and promoting heat recirculation. This 2D disk-type design offers superior adaptability for portable power and micro-thermophotovoltaic applications, boasting better prospects than traditional 3D cylindrical counterparts. Naturally, flames exhibit an ellipsoidal morphology, and this inherent structure becomes unstable when the transition from 3D to 2D combustion hinders the formation of the natural flame structure—particularly the recirculation zone—thus necessitating the deliberate design and artificial construction of a 2D flame structure. Moreover, inherent micro-scale challenges, such as the high surface-to-volume ratio, excessive wall heat loss, and radical quenching, are further amplified, rendering its combustion mechanism far more complex than that of traditional 3D counterparts. Experimental results show notable performance advantages: as the total flow rate increases from 0.20 L/min to 0.40 L/min, the stability limit (equivalence ratio range) expands from 0.404 to 2.60 to 0.095–3.73; peak temperatures reach 728 K (surface) and 1826 K (simulated core); relative heat loss drops from 95.4% to 49.6%. Numerical simulations reveal a fully developed swirl field at high flows, forming a unique “annular anchoring–radial diffusion” flame structure (anchored along the chamber’s edge arc) that avoids central overheating and uneven temperature distribution plaguing cylindrical combustors. Bayesian network data mining identifies a “Velocity → H₂→Structure → Homogeneous/Heterogenous” causal chain (test-set precision: 0.7187), underscoring the need for multi-physical field analysis. This disk-type design overcomes cylindrical limitations, providing a scalable, vane-free solution for high-efficiency micro-combustion.

本研究提出了一种具有双切向入口的平面旋流微燃烧室，其特点是其新颖的圆盘型结构-与传统的圆柱形微燃烧室的关键区别-以提高微尺度能源系统的燃烧稳定性和热效率。燃烧室具有紧凑的圆形腔室（直径10mm，高0.5 mm），氢气/空气混合物产生旋转流动，改善反应物混合，延长停留时间，促进热量再循环。这种2D磁盘型设计为便携式电源和微热光伏应用提供了优越的适应性，比传统的3D圆柱形对应物具有更好的前景。自然地，火焰呈现椭球形态，当从3D到2D燃烧的过渡阻碍了自然火焰结构的形成时，这种固有结构变得不稳定-特别是再循环区域-因此需要故意设计和人工构建2D火焰结构。此外，高表面体积比、壁热损失过大、自由基猝灭等固有的微观挑战进一步放大，使其燃烧机理远比传统3D燃烧复杂。实验结果表明：当总流量从0.20 L/min增加到0.40 L/min时，稳定极限（等效比范围）从0.404 ~ 2.60扩大到0.095 ~ 3.73；峰值温度达到表面728 K，模拟岩心1826 K；相对热损失从95.4%下降到49.6%。数值模拟显示，在高流量时，涡流场充分发展，形成独特的“环形锚定-径向扩散”火焰结构（沿燃烧室边缘弧锚定），避免了中心过热和困扰圆柱形燃烧室的温度分布不均匀。贝叶斯网络数据挖掘识别出“速度→H2→结构→同质/异质”因果链（测试集精度：0.7187），强调了多物理场分析的必要性。这种圆盘式设计克服了圆柱形的限制，为高效微燃烧提供了可扩展的无叶片解决方案。

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引用次数: 0

Selective catalytic oxidation of ammonia by efficient FeOx in coal ash: insights from experimental and DFT studies 粉煤灰中高效FeOx选择性催化氧化氨：来自实验和DFT研究的见解

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138446

Yili Zhang , Su Zhang , Binxin Fang , Liming Cui , Yixiang Zhang , Wenzhen Zhang , Houzhang Tan , Ming Li , Xuebin Wang

Ammonia-coal co-firing is a promising strategy for reducing CO₂ emissions while utilizing existing coal infrastructure. However, challenges remain in controlling nitrogen oxide (NO_x) emissions and unreacted ammonia (NH₃). This study investigates the role of iron oxide (FeO_x) species in coal ash for the selective catalytic oxidation (SCO) of NH₃ during co-firing, combining experimental and density functional theory (DFT) approaches. Four FeO_x species (α-Fe₂O₃, γ-Fe₂O₃, Fe₃O₄, FeO) were systematically evaluated for their NH₃-SCO performance over the temperature range of 300–1000°C under varying oxygen concentrations. Experimental results showed a distinct catalytic activity trend: α-Fe₂O₃ > γ-Fe₂O₃ > Fe₃O₄ > FeO, with Fe₃O₄ exhibiting superior N₂ selectivity due to its abundant surface oxygen species and reduced oxidation state. Oxygen concentration was found to significantly affect reaction pathways; lower O₂ levels enhanced N₂ selectivity for Fe₃O₄ and FeO, while α-Fe₂O₃ and γ-Fe₂O₃ maintained stable oxidation performance. DFT calculations confirmed experimental observations, revealing NH₃ adsorption energies (−1.79 to −0.91 eV) and identifying the *NH₃ → *NH₂ step as the rate-determining step. Mechanistic analysis highlighted an internal selective catalytic reduction (i-SCR) pathway, where energy barriers dictated product selectivity: α-Fe₂O₃/γ-Fe₂O₃ favored NO formation, whereas Fe₃O₄/FeO promoted N₂ generation. This study provides valuable insights into the catalytic behavior of different FeO_x species in coal ash, offering a foundation for optimizing ammonia-coal co-firing systems to mitigate both NO_x and NH₃ emissions synergistically.

氨煤共烧是一种很有前途的策略，可以在利用现有煤炭基础设施的同时减少二氧化碳排放。然而，在控制氮氧化物（NOx）排放和未反应氨（NH3）方面仍然存在挑战。本研究结合实验和密度泛函理论（DFT）研究了煤灰中氧化铁（FeOx）在共烧过程中NH3选择性催化氧化（SCO）中的作用。研究了α-Fe2O3、γ-Fe2O3、Fe3O4、FeO四种FeOx在300 ~ 1000℃温度范围内不同氧浓度下的NH3-SCO性能。实验结果表明：α-Fe2O3 >； γ-Fe2O3 > Fe3O4 >； FeO具有明显的催化活性趋势，其中Fe3O4由于其丰富的表面氧和还原的氧化态，表现出较好的N2选择性。氧浓度对反应途径有显著影响；较低的O2浓度增强了Fe3O4和FeO对N2的选择性，而α-Fe2O3和γ-Fe2O3则保持稳定的氧化性能。DFT计算证实了实验结果，得到了NH3的吸附能（- 1.79 ~ - 0.91 eV），并确定了*NH3→*NH2步骤为速率决定步骤。机理分析强调了内部选择性催化还原（i-SCR）途径，其中能量势垒决定了产物的选择性：α-Fe2O3/γ-Fe2O3有利于NO的生成，而Fe3O4/FeO促进N2的生成。该研究为不同FeOx物种在煤灰中的催化行为提供了有价值的见解，为优化氨煤共烧系统以协同减少NOx和NH3排放提供了基础。

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引用次数: 0

Experimental and numerical study on the effects of preheat temperature and steam dilution rate on the laminar burning velocity of CH4/O2/H2O 预热温度和蒸汽稀释率对CH4/O2/H2O层流燃烧速度影响的实验与数值研究

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-29 DOI: 10.1016/j.fuel.2026.138535

Shun Meng , Chunyu Zhang , Xinbin Ge , Shun Bian , Yang Hua , Changfa Tao , Yejian Qian , Peiyong Ma , Chunmei Wang

O₂/H₂O combustion represents a next-generation oxy-fuel technology characterized by near-zero CO₂ emissions. This study investigates the laminar burning velocity (LBV) of CH₄/O₂/H₂O mixtures at 0.1 MPa in a constant volume combustion chamber integrated with high-speed schlieren imaging technique. Systematic measurements were conducted across preheating temperatures (400–500 K) and steam dilution ratios (X_H2O = 0.4–0.7). Detailed kinetic modeling using CHEMKIN software elucidated the coupled effects of thermal and chemical on flame radical and reaction kinetics. The basic flame data of LBV under different preheating temperature and steam dilution ratios conditions were obtained experimentally. The LBV exhibits exponential enhancement with increasing preheating temperature under different equivalence ratios (0.6–1.4), while displaying linear decline with steam dilution increase. Steam demonstrates dual functionality. Dominant physical effects through heat absorption and concentration dilution reduce flame reactivity. Steam chemical participation elevates relative molar fractions of OH, whereas O/H radical populations decrease. This radical redistribution promotes CH₃ to CH₄ recombination while suppressing CH₄ oxidation kinetics. Reaction pathway analysis shows 16.7% increase through CH₃ + H + M → CH₄ in the consumption path of CH₃, collectively governing LBV reduction mechanisms. The quantified temperature/steam coupling effects on the flame characteristics provide theoretical guidance for optimizing oxygen-enriched steam combustion systems. The findings of this study provide technical support for the development of O₂/H₂O combustion technology, thereby contributing to the advancement of carbon–neutral combustion.

O2/H2O燃烧是下一代全氧燃料技术，其特点是二氧化碳排放量接近于零。采用高速纹影成像技术，研究了CH4/O2/H2O混合物在0.1 MPa时的层流燃烧速度（LBV）。系统测量了预热温度（400-500 K）和蒸汽稀释比（XH2O = 0.4-0.7）。利用CHEMKIN软件进行了详细的动力学建模，阐明了热化学耦合作用对火焰自由基和反应动力学的影响。实验得到了不同预热温度和蒸汽稀释比条件下LBV的基本火焰数据。在不同当量比（0.6 ~ 1.4）下，随着预热温度的升高，LBV呈指数型增强，随着蒸汽稀释度的增加，LBV呈线性下降。Steam展示了双重功能。通过吸热和浓度稀释的主要物理效应降低了火焰的反应性。蒸汽化学参与提高了OH的相对摩尔分数，而O/H自由基数量减少。这种自由基的再分配促进了CH3到CH4的重组，同时抑制了CH4氧化动力学。反应路径分析表明，CH3消耗路径中CH3 + H + M→CH4增加16.7%，共同控制LBV还原机制。量化的温度/蒸汽耦合效应对火焰特性的影响为优化富氧蒸汽燃烧系统提供了理论指导。本研究的发现为O2/H2O燃烧技术的发展提供了技术支持，从而促进了碳中性燃烧的发展。

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引用次数: 0