IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-31 DOI: 10.1016/j.fuel.2026.138553

Xinlu Han , Huizhen Li , Ye Yuan , Zihe Gao

Dimethyl ether (DME), a renewable biofuel, is a potential alternative to conventional engine fuels. However, fundamental flame propagation characteristics such as laminar burning velocity remain lacking in the literature under the very-lean conditions, hindering comprehensive understanding for advanced combustion design, despite the low-pollutant and high-efficiency potential of lean-burn engines. In the present study, laminar burning velocity of unconventionally-lean DME flames was measured at 298 K and 1 atm using the heat flux method. The experimental conditions cover equivalence ratio as low as 0.3 that have never been reported before, which was achieved through oxygen enrichment strategy. The measured data, including uncertainties in burning velocity, equivalence ratio, and oxygen ratio, were compared against six widely used detailed kinetic models. All models reproduced the DME data trends well, with quantitative deviations less than twice the experimental uncertainty in average. The DME laminar burning velocities were compared to those of its isomer, ethanol (C₂H₅OH), revealing their difference increases with both O₂ enrichment ratio and equivalence ratio. Using the NUIG1.3 model and the model by Han (which both reproduced ethanol flames within twice the experimental uncertainty), systematic analysis quantified isomer effects through thermodynamic, transport, and kinetic differences. Each difference contributes synergistically to amplified burning velocity disparities, especially low fuel mole fractions in unconventionally-lean, low-O₂-enriched unburnt mixtures limit thermodynamic and transport contributions. Extending this analysis to other isomers leads to a hypothesis, i.e., the

S_{L}

differences among different isomers under unconventionally-lean, low-O₂-enriched conditions may be estimated simply from the differences in their bond dissociation energies. Due to the lack of corresponding experimental data, a first-step evaluation was carried out through simulations using the NUIG1.3 model. If the hypothesis can be proved by future measurements, it can benefit ultra-lean applications including uncharacterized isomers.

二甲醚（DME）是一种可再生生物燃料，是传统发动机燃料的潜在替代品。然而，尽管稀燃发动机具有低污染和高效率的潜力，但文献中仍然缺乏基本的火焰传播特性，如层流燃烧速度，这阻碍了对先进燃烧设计的全面理解。本文采用热流密度法测量了异贫二甲醚火焰在298 K和1 atm下的层流燃烧速度。实验条件涵盖了以前从未报道过的低至0.3的等效比，这是通过富氧策略实现的。测量数据，包括燃烧速度、当量比和氧比的不确定度，与六种广泛使用的详细动力学模型进行了比较。所有模型都很好地再现了DME数据的趋势，其定量偏差平均小于实验不确定性的两倍。将二甲醚的层流燃烧速度与其异构体乙醇（C2H5OH）的层流燃烧速度进行了比较，发现两者的差异随着O2富集比和当量比的增加而增大。使用NUIG1.3模型和Han模型（两者都在实验不确定度的两倍内再现了乙醇火焰），通过热力学、输运和动力学差异对异构体效应进行了系统分析。每一种差异都会协同放大燃烧速度差异，特别是在非常规稀薄、低o2富集的未燃烧混合物中，低燃料摩尔分数限制了热力学和输运贡献。将这一分析扩展到其他异构体，可以得出一个假设，即不同异构体在非常规稀薄、低o2富集条件下的SL差异可以简单地从它们的键解离能的差异来估计。由于缺乏相应的实验数据，我们使用NUIG1.3模型通过模拟进行第一步评估。如果该假设可以通过未来的测量证明，它将有利于包括未表征异构体在内的超精益应用。

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引用次数: 0

Condensable particulate matter adsorptively removed by metal-modified activated carbon from simulated and coal combustion flue gas 金属改性活性炭吸附去除模拟烟气和燃煤烟气中的可冷凝颗粒物

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-31 DOI: 10.1016/j.fuel.2026.138495

Yue Zou , Xiaowei Liu , Xiangli Liu , Aoyang Zhang , Zijian Zhou , Minghou Xu

Condensable particulate matter (CPM) emitted from coal-fired power plants presents increasing environmental and health risks due to its high content of semi-volatile organic compounds. Among them, dibutyl phthalate (DBP), a representative phthalate ester and endocrine-disrupting chemical, is frequently identified as a dominant organic constituent in CPM but is poorly removed by conventional air pollution control devices.

In this study, a metal-modified activated carbon adsorbent was developed and evaluated for its efficiency in removal of CPM. The adsorption performance and mechanism of the material for DBP were investigated under simulated flue gas conditions, followed by validation of its CPM and DBP removal effectiveness through laboratory-scale coal combustion experiments. Among tested materials, Fe³⁺-impregnated activated carbon (5%Fe-AC) demonstrated the highest removal efficiency. Mechanistic analysis indicated that Fe³⁺ promotes the formation of coordination complexes with DBP, significantly enhancing physicochemical adsorption and resulting in a 77.6% improvement in removal efficiency. Under simulated conditions, 5%Fe-AC achieved 74.85% DBP removal, while in combustion tests it removed 30.52% of DBP, 37.00% of total organics, and 42.26% of total CPM mass. This work provides a targeted supported strategy for the removal of CPM and its hazardous organics, offering insights into the development of efficient adsorbents for air pollution control.

燃煤电厂排放的可冷凝颗粒物（CPM）由于其高含量的半挥发性有机化合物而对环境和健康造成越来越大的风险。其中，邻苯二甲酸二丁酯（dibutyl phthalate， DBP）是一种具有代表性的邻苯二甲酸酯和内分泌干扰化学物质，经常被确定为CPM中的主要有机成分，但传统的空气污染控制装置很难去除。本研究开发了一种金属改性活性炭吸附剂，并对其去除CPM的效率进行了评价。在模拟烟气条件下，研究了该材料对DBP的吸附性能和机理，并通过实验室规模的燃煤实验验证了其CPM和DBP的去除效果。实验材料中，Fe3+浸渍活性炭（5%Fe-AC）的去除率最高。机理分析表明，Fe3+促进了与DBP的配位配合物的形成，显著增强了DBP的理化吸附，去除率提高了77.6%。在模拟条件下，5%Fe-AC对DBP的去除率为74.85%，而在燃烧试验中，DBP去除率为30.52%，总有机物去除率为37.00%，总CPM质量去除率为42.26%。这项工作为去除CPM及其有害有机物提供了有针对性的支持策略，为开发有效的吸附剂来控制空气污染提供了见解。

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引用次数: 0

Key three-material system in alkaline water electrolysis for hydrogen production: Systematic review and future outlook 碱水电解制氢关键三料系统综述及展望

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-31 DOI: 10.1016/j.fuel.2026.138509

Zhimeng Zhao , Hexu Sun , Jianhui Li , Zhanying Sun , Yingjun Guo

Alkaline Water Electrolysis (AWE) has become the mainstream technology for current green hydrogen production due to its high technical maturity, low equipment cost, and scale advantage. However, it still faces challenges such as bottlenecks in key material performance, insufficient adaptability to dynamic operating conditions, and resource dependence. Thus, there is an urgent need to promote efficiency improvement and cost reduction through material innovation. Although AWE technology has developed relatively maturely, existing review literatures lack considerations on the systematic synergistic optimization of AWE materials. To address this issue, this paper systematically reviews the action mechanisms and material properties of various hydrogen production materials from three core dimensions: electrodes (catalysts), membranes, and electrolytes. It conducts an in-depth analysis of the optimization mechanisms of material properties and proposes targeted optimization strategies. Meanwhile, it clarifies the key challenges and future development directions faced by various materials, and lists the directions for engineering optimization. Aiming to help readers gain a comprehensive understanding of electrolysis systems, broaden research ideas, and provide theoretical support and technical route guidance for constructing high-efficiency electrolysis systems with material synergistic optimization. Among them, carbon-based composite materials with excellent structural designability, self-healing membranes with a unique dynamic self-healing design, and hydrogen production via seawater electrolysis with significant cost-effectiveness and deep coupling with renewable energy all show great application potential in the future.

碱性水电解（AWE）技术成熟度高、设备成本低、具有规模优势，已成为当前绿色制氢的主流技术。但仍面临关键材料性能瓶颈、对动态工况适应性不足、资源依赖性等挑战。因此，迫切需要通过材料创新来促进效率的提高和成本的降低。虽然AWE技术发展相对成熟，但现有的综述文献缺乏对AWE材料系统协同优化的考虑。为了解决这一问题，本文从电极（催化剂）、膜和电解质三个核心维度系统地综述了各种制氢材料的作用机理和材料性能。深入分析了材料性能的优化机理，提出了有针对性的优化策略。同时，明确了各种材料面临的主要挑战和未来发展方向，并列出了工程优化的方向。旨在帮助读者全面了解电解系统，拓宽研究思路，为构建具有材料协同优化的高效电解系统提供理论支持和技术路线指导。其中，具有优异结构可设计性的碳基复合材料、具有独特动态自愈设计的自愈膜、具有显著成本效益且与可再生能源深度耦合的海水电解制氢等，在未来都显示出巨大的应用潜力。

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引用次数: 0

Secondary fractal evolution mechanism of coal seam fractures and seepage under mechanical cavitation disturbance: Implications for CBM extraction 机械空化扰动下煤层裂隙和渗流的二次分形演化机制：对煤层气开采的启示

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-31 DOI: 10.1016/j.fuel.2026.138494

Cunyang Lu , Haifeng Wang , Pingdingqi Tuo , Xinghua Zhang , Jiale Zhang

Mechanical cavitation technology (MCT) can effectively enhance the production of coalbed methane (CBM). However, quantitative descriptions of reservoir fracture evolution and CBM migration patterns following MCT remain scarce. By integrating N₂ adsorption, DEM simulation, and fractal theory, this study quantified the secondary fractal evolution patterns of fractures and permeability responses in CBM reservoirs under the MCT. Adsorption experiments indicate that after coal fragmentation, the surface roughness of pores increases, whereas structural heterogeneity decreases. A stress‒damage model incorporating equivalent plastic softening, coupled with the DEM, reveals four successive fracturing stages: (I) circular slow growth, (II) elliptical rapid growth, (III) X-shaped extension, and (IV) compaction‒fracture cycles. The temporal evolution of fractures can be quantified via the ‘fracture gradient dimension’ as follows: formation stage − activation stage − stabilization stage, with the synchronous expansion of permeability enhancement zones within coal seams. The spatial evolution of fractures follows a secondary fractal sequence: activation zone − formation zone − stabilization zone, with concurrent enhancement of coal seam permeability. Coupled spatiotemporal fractal mechanisms enable coal seams to achieve both maximum CBM production efficiency and economic benefits when they reach the FESS & FESZ states. Field trials have demonstrated that MCT can enhance coalbed permeability by two orders of magnitude and increase CBM production efficiency by 2.5 times. By integrating fractal theory with discrete element modelling, the evolution of fracture fields under cavitation disturbances has been measured and quantified. This provides a universal framework for optimizing MCT parameters and establishes a theoretical foundation for efficient CBM extraction.

机械空化技术（MCT）可以有效地提高煤层气的产量。然而，MCT后储层裂缝演化和煤层气运移模式的定量描述仍然很少。结合N2吸附、DEM模拟和分形理论，量化了MCT作用下煤层气储层裂缝和渗透率响应的次生分形演化模式。吸附实验表明，煤破碎后孔隙表面粗糙度增大，结构非均质性减小。结合等效塑性软化和DEM的应力-损伤模型揭示了四个连续的压裂阶段：(I)圆形缓慢增长，（II）椭圆快速增长，（III） x形扩展和（IV）压实-破裂循环。裂缝的时间演化可以通过“裂缝梯度维数”来量化：形成阶段—活化阶段—稳定阶段，煤层内渗透率增强带同步扩展。裂缝空间演化遵循活化区-形成区-稳定化区二级分形序列，并伴有煤层渗透率的增强。耦合的时空分形机制使煤层在达到FESS & FESZ状态时，煤层气生产效率和经济效益均达到最大。现场试验表明，MCT可使煤层气渗透率提高2个数量级，煤层气生产效率提高2.5倍。将分形理论与离散元模型相结合，对空化扰动下裂缝场的演化进行了测量和量化。这为优化MCT参数提供了一个通用框架，为高效提取煤层气奠定了理论基础。

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引用次数: 0

Integrating free radical chain reaction kinetics into crude oil In situ combustion modeling: a novel approach for ignition mechanism characterization 将自由基链式反应动力学集成到原油原位燃烧模型中：一种新的点火机理表征方法

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138518

Alexandra S. Ushakova , Nikolay N. Mikhailov , Mohammed A. Khelkhal , Alexey V. Vakhin

This study introduces a novel integrated approach to modeling crude oil in situ combustion by incorporating free radical chain reaction kinetics to address the critical limitation of conventional models: their inability to accurately predict ignition behavior. Current Arrhenius-based models fail to capture the transient ignition phase, a critical element for field implementation safety and efficiency. We developed a hybrid modeling framework combining conventional combustion kinetics with chain reaction mechanisms for the initial oxidation stages (150-250°C). The methodology was validated using pressurized differential scanning calorimetry (PDSC) experiments at 5 MPa with heating rates of 2-10°C/min on light and middle crude oils, combined with SARA compositional analysis. Two-reaction and four-reaction Arrhenius schemes were systematically evaluated and matched to experimental data. The chain reaction approach achieved 14% relative error in predicting low-temperature oxidation heat release, representing more than 50% improvement over conventional models (30% error). This physics-based framework enables accurate ignition timing prediction − a critical capability previously unattainable through traditional hydrodynamic modeling. The validated methodology demonstrates broad applicability across different crude oil types and provides a practical pathway for integrating advanced kinetic mechanisms into commercial reservoir simulators for enhanced in situ combustion project design.

本研究引入了一种新的综合方法来模拟原油的原位燃烧，通过结合自由基链反应动力学来解决传统模型的关键局限性：它们无法准确预测点火行为。目前基于arrhenius的模型无法捕捉瞬态点火阶段，这是现场实施安全性和效率的关键因素。我们开发了一个混合建模框架，将传统燃烧动力学与初始氧化阶段（150-250°C）的链式反应机制结合起来。通过加压差示扫描量热法（PDSC）实验验证了该方法，实验温度为5 MPa，加热速率为2-10°C/min，并结合SARA成分分析。系统地评价了两反应和四反应的Arrhenius方案，并与实验数据进行了匹配。链式反应方法在预测低温氧化热释放方面的相对误差为14%，比传统模型（误差为30%）提高了50%以上。这种基于物理的框架能够实现精确的点火时间预测-这是以前通过传统流体动力学建模无法实现的关键能力。经过验证的方法显示了对不同原油类型的广泛适用性，并为将先进的动力学机制集成到商业油藏模拟器中，以增强原位燃烧项目设计提供了实用途径。

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引用次数: 0

A numerical investigation of coupled geometric effects on methane-air deflagration dynamics 耦合几何效应对甲烷-空气爆燃动力学的数值研究

IF 7.5 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2026-01-30 DOI: 10.1016/j.fuel.2026.138541

Jingui Wang , Jianhao Wei , Chensheng Lin , Junan Wu , Su Zhang

Obstacle-driven flame acceleration in confined methane–air deflagrations poses a persistent hazard to industrial and utility corridors. Internal geometry-shape, blockage ratio (BR), and thickness-regulates turbulence–flame coupling, yet their combined influence remains incompletely resolved. This study employs a validated large-eddy simulation (LES) framework with adaptive mesh refinement and a partially premixed combustion model to examine these interactions in a two-dimensional straight duct. The matrix sweeps rectangular, elliptical, and triangular obstacles across BR = 0.3, 0.5, 0.7, while thickness (10, 20, 30 mm) is varied at BR = 0.3 to isolate thickness effects under comparable confinement, yielding 15 total cases (five cases per obstacle shape). Under the present conditions, BR appears to be the dominant accelerator: increasing BR from 0.3 to 0.7 raises the maximum pressure-rise rate, (dP/dt)_max, by as much as 637% in this dataset. A second trend emerges at low BR, hereafter referred to as a thickness-stabilization effect. Increasing thickness from 10 to 30 mm consistently lowers the assessed hazard; in the rectangular configuration, (dP/dt)_max decreases by approximately 74%. Flow-field diagnostics offer a coherent explanation. Thin plates generate highly unstable shear layers that roll up almost immediately, promote fine-scale wrinkling, and accelerate the front. With added thickness, the obstacle behaves in a splitter-plate-like manner: the onset of shear-layer roll-up is delayed, the near wake is stabilized, and shedding organizes into more coherent vortical patterns-behavior that is consistent with slower propagation. Shape continues to organize the wake and flame brush. Rectangular obstacles tend to fragment the front and bias it toward asymmetry, whereas elliptical profiles support smoother, more continuous propagation under otherwise similar conditions. Taken together, the results suggest that obstacle geometry maps systematically onto deflagration dynamics and may inform evidence-based guidance for passive safety design in confined infrastructure.

在受限的甲烷-空气爆燃中，障碍物驱动的火焰加速对工业和公用设施走廊造成了持续的危害。内部几何形状、堵塞比（BR）和厚度调节湍流-火焰耦合，但它们的综合影响尚未完全解决。本研究采用经过验证的大涡模拟（LES）框架，采用自适应网格细化和部分预混燃烧模型来研究二维直管中的这些相互作用。该矩阵在BR = 0.3、0.5、0.7处扫描矩形、椭圆形和三角形障碍物，而在BR = 0.3处改变厚度（10、20、30 mm），以隔离相同约束条件下的厚度影响，共产生15个案例（每个障碍物形状5个案例）。在目前的条件下，BR似乎是主要的加速器：在这个数据集中，BR从0.3增加到0.7，最大压力上升速率（dP/dt）max提高了637%。第二种趋势出现在低BR，下文称为厚度稳定效应。厚度从10毫米增加到30毫米，可以持续降低评估的风险；在矩形结构中，（dP/dt）max减小了约74%。流场诊断提供了一个连贯的解释。薄板产生高度不稳定的剪切层，这些剪切层几乎立即卷起，促进了细尺度的起皱，并加速了前缘。随着厚度的增加，障碍物表现出类似分裂板的行为：剪切层卷起的开始被推迟，近尾迹稳定，脱落组织成更连贯的旋涡模式——这种行为与较慢的传播相一致。形状继续组织尾迹和火焰刷。矩形障碍物往往会使锋面破碎并使其偏向不对称，而椭圆轮廓在其他类似条件下支持更平滑，更连续的传播。综上所述，研究结果表明，障碍物几何形状可以系统地映射到爆燃动力学，并可能为受限基础设施的被动安全设计提供循证指导。

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引用次数: 0

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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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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