Fuel最新文献

{"title":"Low-temperature CO2 activation and methanation promoted by a hydroxyl-bearing Ni/complex-support catalyst","authors":"Baowang Lu ,&nbsp;Jiahao Zhang ,&nbsp;Jingyun Chen ,&nbsp;Zhihua Han ,&nbsp;Yuyu Liu ,&nbsp;Yanyan Diao ,&nbsp;Xingyun Li ,&nbsp;Zepeng Wang ,&nbsp;Zhou-jun Wang ,&nbsp;Chaonan Cui","doi":"10.1016/j.fuel.2026.138275","DOIUrl":"10.1016/j.fuel.2026.138275","url":null,"abstract":"<div><div>To gain a deeper understanding of the CO₂ activation and methanation mechanism from a deeper perspective, a brand-new method was employed to track CO₂ dissociation via DRIFT spectroscopy, instead of the traditional method of monitoring the methanation process with DRIFT spectroscopy. Herein, we designed complex-supports by incorporating CaO or CeO₂ into SBA-15 to prepare Ni-based catalyst. These complexes significantly enhanced the catalytic activity of CO₂ methanation, lowering the reaction temperature by approximately 60 °C. The CeO₂ composite improved catalyst stability by suppressing polymeric carbon, while CaO exerted the opposite effect. Increasing the NiO amount in Ni/CeO₂-SBA-15 had no significant impact on CH₄ selectivity of ∼100 %, whereas it reduced CH₄ selectivity in Ni/CaO-SBA-15 to below 100 %. Based on DRIFT observations, H₂ dissociation species (Ni(H)) on Ni, spillover H species (Ni(H)_s) and OH species (Ni(OH)_s) were identified as three driving forces for CO₂ dissociation. By compounding CaO or CeO₂ into SBA-15, Ni(OH)s sites were found to significantly enhance the CO₂ dissociation process, while no obvious enhancement was observed for Ni(H) and Ni(H)_s sites. CO and formate were detected as intermediates in CO₂ methanation, and the formation of CH_x was promoted by the CaO or CeO₂ composite. Combined with theoretical calculations, the role of surface OH groups in the CO₂ hydrogenation mechanism was also investigated. The results demonstrated that the methanation process could be significantly accelerated by introducing the CeO₂ composite. This fundamental understanding of the CO₂ methanation mechanism will facilitate the design of highly efficient catalysts and promote their commercial application.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138275"},"PeriodicalIF":7.5,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring the physicochemical properties of alumina-metal-organic framework templated nickel nanocatalysts through basic promoter (Ce, La, Mg) incorporation for enhanced activity in methane tri-reforming","authors":"Arisha Sharma,&nbsp;Anjali Garg,&nbsp;Prakash Biswas","doi":"10.1016/j.fuel.2026.138269","DOIUrl":"10.1016/j.fuel.2026.138269","url":null,"abstract":"<div><div>The effect of basic promoters on the alumina metal organic frameworks (MOF) templated nickel-based catalyst was examined for the tri-reforming of methane. The objective of this study was to enhance the CO₂ conversion and to produce the synthesis gas with a H₂/CO molar ratio of 1.5–2.5, which is a feedstock in the Fischer-Tropsch process for the synthesis of methanol and/or dimethyl ether. A series of MgO, CeO₂, and La₂O₃ promoted 5 wt% Ni-alumina (Ni/Al_M-53) derived from the MOF was synthesized via the solvothermal method, followed by the co-impregnation technique. The tri-reforming activity of the catalysts was evaluated in a tubular downflow packed bed reactor at atmospheric pressure in the temperature range of 600–800 °C. Results demonstrated that the CO₂ conversion activity was significantly improved after the incorporation of an appropriate amount of basic promoter (2.5 % Ce, 1 % La, 1 % Mg) into the Ni-alumina MOF templated catalyst. The CO₂ conversion increased from 37.5 % to ∼48 % with a simultaneous improvement of the H₂/CO ratio from 3.2 to 2.5. This improvement of the catalytic activity was attributed to the generation of oxygen vacancies, formation of a stable spinel structure, enhanced metal dispersion, strong metal-support interaction, electron transfer, and the availability of more basic sites after the addition of a basic promoter into the Ni/Al_M-53 catalyst. The strong metal-support interaction combined with the oxygen vacancies created a carbon-resistant atmosphere on the catalyst surface, which suppressed carbon deposition and metal sintering even after prolonged reaction duration of &gt;100 h at a high reaction temperature of 800 °C.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138269"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tandem Rh-based structured reformer and Ni-YSZ SOFC for decentralized gasoline-to-power conversion","authors":"N.V. Ruban ,&nbsp;V.N. Rogozhnikov ,&nbsp;D.A. Svintsitskiy ,&nbsp;V.P. Pakharukova ,&nbsp;P.V. Snytnikov ,&nbsp;J.W. Thybaut ,&nbsp;D.I. Potemkin","doi":"10.1016/j.fuel.2026.138249","DOIUrl":"10.1016/j.fuel.2026.138249","url":null,"abstract":"<div><div>This work reports on the performance of a 0.24 wt% Rh/Ce_0.75Zr_0.25O₂–δ–η-Al₂O₃/FeCrAl structured catalyst in the autothermal reforming of commercial gasoline with a research octane number of 92. Stable syngas production amounting to 70 Nl·h⁻¹ containing of 33.8 vol% H₂ and 9.8 vol% CO was demonstrated over 50 h of continuous operation. The origin of the high catalytic efficiency was elucidated by physicochemical characterization (XPS, STEM, XRD), which confirmed the role of Rh redox flexibility (Rh³⁺ ⇄ Rh⁰) and Ce⁴⁺ ⇄ Ce³⁺ cycling in suppressing carbon formation and maintaining active site dispersion. The compatibility of the produced syngas with Ni–YSZ solid oxide fuel cells was assessed, and a reformer–SOFC tandem concept was proposed to supply 50 W to telecommunication equipment, with operational parameters derived from the present reformer performance. Such a system highlights the potential of integrating catalytic reforming with SOFC conversion for decentralized power generation in remote applications where access to centralized infrastructure is limited.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138249"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of temperature on the modification and carbon sequestration of lignite via synergistic supercritical CO2 and microbial treatment","authors":"Daping xia ,&nbsp;Hang Lv ,&nbsp;Kuo Jian ,&nbsp;Yan Liu ,&nbsp;Bin Xu ,&nbsp;Huizhen Chang ,&nbsp;Liuqi Jia","doi":"10.1016/j.fuel.2025.138245","DOIUrl":"10.1016/j.fuel.2025.138245","url":null,"abstract":"<div><div>Against the backdrop of global climate change, coal seam CO₂ geological sequestration technology has garnered extensive attention due to its significant potential. To enhance the CO₂ adsorption capacity of coal, the synergistic modification of lignite using supercritical CO₂ (ScCO₂) and microorganisms has emerged as a promising technical approach, in which temperature regulation plays a pivotal role. Through experimental studies conducted under different temperature conditions, the evolution of coal structure and variations in the liquid-phase environment were systematically analyzed. The experimental results indicate that 40 °C is the optimal temperature for the synergistic effects, at which the pore structure of coal is most notably developed, with the specific surface area and total pore volume increasing to 11.253 m²/g and 0.14589 cm³/g, respectively. Concurrently, the oxygen-containing functional groups on the coal surface increased notably, the degree of ordering of the microcrystalline structure was reduced, and the reactivity of the coal matrix was enhanced. Under this temperature condition, microbial metabolism was most active, which efficaciously neutralized the system’s acidity and promoted the formation of HCO₃^– and CO₃^2–, thereby creating favorable conditions for the conversion of CO₂ into stable carbonate minerals. In contrast, when the temperature was raised to 45 °C, microbial activity was inhibited, leading to a significant reduction in the modification effect. These findings confirm that temperature is a key parameter controlling the efficiency of synergistic carbon sequestration. Future research should further explore the coupling effects of temperature and pressure, as well as microbial metabolic mechanisms, to facilitate the practical application of this technology.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138245"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of CO2 and increased initial pressure on hydrothermal liquefaction for the production of high value fatty acids","authors":"D. Liakos ,&nbsp;Maria Iosifidou ,&nbsp;S. Vakalis","doi":"10.1016/j.fuel.2026.138317","DOIUrl":"10.1016/j.fuel.2026.138317","url":null,"abstract":"<div><div>Hydrothermal liquefaction (HTL) of waste biomasses has been widely studied, yet the influence of the reaction atmosphere on carboxylation chemistry is often overlooked. In this study, HTL of anise (<em>Pimpinella anisum</em> L.) waste was performed at 310, 350 and 390 °C solely with air (no added pressure), under N₂ with and without increased initial pressure, solely with CO₂, and with combined N₂/CO₂ and increased pressure. The aim was to assess how total pressure and gas/ atmosphere composition affect product distribution and high‑value compound formation. Dissolved CO₂ was found to acidify the aqueous phase and participate in carboxylation reactions that convert hydrolysis intermediates into volatile fatty acids (VFAs), as measured via a GC-BID in the form of fatty‑acid methyl esters (FAMEs). Chemical oxygen demand (COD) in the aqueous phase increased from 10,000 to 30000 mg/ L and was consistently higher under CO₂. Hydrochar higher heating value peaked at approximately 35 MJ/ kg at 350 °C and declined at 390 °C. CO₂‑rich runs exhibited an order‑of‑magnitude increase in VFA production, with acetic‑acid concentrations up to 2 g/ L. FAMEs formation increased with temperature; at 390 °C the combined N₂/ CO₂ system produced methyl hexanoate concentrations of approx. 13 g/ L and methyl octanoate 11.9 g/ L, more than threefold higher than in single‑gas or non‑pressurized runs. One‑way ANOVA revealed that pressure significantly influenced VFA and FAME yields at 310–350 °C but this effect diminished at 390 °C. These results highlight the importance of optimizing both gas atmosphere and pressure in HTL processes and demonstrate that reactive CO₂ atmospheres can drive carboxylation pathways leading to higher yields of valuable fatty acids.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138317"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the differences in ignition and combustion characteristics between raw coal and pyrolyzed char: A combined PLIF measurement and DFT calculation","authors":"Yawei Song ,&nbsp;Sheng Su ,&nbsp;Qifu Lin ,&nbsp;Longwei Chen ,&nbsp;Chengzhou Liu ,&nbsp;Weiye Chen ,&nbsp;Zhenyang Li ,&nbsp;Yiman Jiang ,&nbsp;Dianwu Wu ,&nbsp;Hansheng Feng ,&nbsp;Guangnan Luo ,&nbsp;Jun Xiang","doi":"10.1016/j.fuel.2026.138268","DOIUrl":"10.1016/j.fuel.2026.138268","url":null,"abstract":"<div><div>Fuel selection is critical for achieving stable low-load combustion and rapid load response in coal-fired power plants. As an important source of steam coal, understanding the combustion behavior of low-rank coal and its pyrolyzed char is essential for fuel optimization. The ignition behaviors, OH radical generation, and flame front evolution of the raw coal and chars pyrolyzed at four temperatures (500 °C, 600 °C, 700 °C and 800 °C) were investigated using OH-Planar laser-induced fluorescence (OH-PLIF). Density functional theory (DFT) calculations were conducted to clarify the interaction between polycyclic aromatic hydrocarbons (PAHs) and H radicals during volatile combustion. The results showed that raw coal had a significantly shorter ignition delay time (<em>t</em>_ign) than pyrolyzed chars, and increasing pyrolysis temperature led to longer <em>t</em>_ign. Similarly, raw coal also displayed a higher peak flame temperature due to the strong radiative heat transfer of sooty flames, while chars prepared at lower temperatures showed relatively higher peak temperatures among the char samples. Based on the results of OH radical intensity profile, the coal combustion process exhibited two-peaks pattern, corresponding to volatile flame duration stage and char combustion stage, whereas the pyrolyzed chars exhibited one-peak pattern. The OH intensity at ignition moment of raw coal was higher than that of other four pyrolyzed chars, consistent with its shorter <em>t</em>_ign. Whereas, the peak OH radical intensity of raw coal during two stages are almost lower than the peak OH intensity of pyrolyzed chars, among them the peak OH intensity during volatile flame duration stage was much lower than that of others observed. DFT calculations showed that H radicals promote PAHs formation by lowering reaction barriers, but their consumption by PAHs reduces OH production via <em>H</em> + <em>O</em>₂ → <em>OH</em> + <em>O</em>. This explains the significantly weaker OH intensity observed during the volatile combustion of raw coal compared with that during char combustion stage and the combustion of pyrolyzed char.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138268"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different jet forms on the gas–solid flow behavior in a downer reactor","authors":"Zihan Yan ,&nbsp;Huimin Yin ,&nbsp;Lining Wu ,&nbsp;Mengxin Wen ,&nbsp;Zhihang Zheng ,&nbsp;Xiuying Yao ,&nbsp;Chunxi Lu","doi":"10.1016/j.fuel.2026.138293","DOIUrl":"10.1016/j.fuel.2026.138293","url":null,"abstract":"<div><div>In this study, to explore the influence of nozzle jets on the gas–solid flow behavior in a downer reactor, different forms of jets are introduced in the fully developed section of the downer reactor. Numerical simulations are conducted to examine the effects of different jet forms (upward and downward-inclined jets) and jet angles on the gas–solid flow behavior. The Kutta-Joukowski theorem, which was originally developed in aerodynamics, is adopted in this study to analyze lateral forces in the gas–solid flow system. The results show that after the introduction of a jet, the radial particle velocity distribution in the downer reactor becomes more uniform. Compared to downward inclined jets, upward jets, which interact counter-currently with the particle flow, are more effective in increasing the particle concentration within the downer reactor. The solid holdup at the reactor center in the dense-phase region is 1 to 6.6 times higher in the presence of jets than in the absence of jets at the same gas flow rate. For both upward and downward jets, the 60° axial nozzle-wall angle shows the best center concentration enhancement effect. Additionally, the larger the axial nozzle-wall angle is, the easier it is for particles to recover to the uniform distribution.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138293"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined effects of pre-chamber nozzle diameter and fuel reactivity on jet ignition characteristics of ammonia-hydrogen blends","authors":"Jinguang Li,&nbsp;Lei Wang,&nbsp;Gequn Shu,&nbsp;Xingqian Mao,&nbsp;Haiqiao Wei,&nbsp;Jiaying Pan","doi":"10.1016/j.fuel.2026.138302","DOIUrl":"10.1016/j.fuel.2026.138302","url":null,"abstract":"<div><div>Compared to active pre-chambers, passive pre-chambers offer significant advantages due to their simple structure and the elimination of major modifications to the cylinder head. The nozzle diameter is a key parameter affecting jet ignition characteristics, yet its effects under different reactive conditions, particularly in combination with fuel reactivity, remain insufficiently understood. This study investigates the influence of nozzle diameter on jet ignition characteristics of ammonia-hydrogen blends using a rapid compression machine equipped with a passive pre-chamber, allowing systematic variation of hydrogen blending ratios. Results indicate that excessively small nozzle diameters generate a strong throttling effect, suppressing pre-chamber ignition, whereas higher fuel reactivity enhances ignition. Conversely, high-speed jets promote intense shear interactions with the mixture, leading to significant heat loss and combustion instability in the main chamber. Large nozzle diameters result in lower jet kinetic energy and weaker turbulence, slowing flame propagation during the late combustion phase. For hydrogen blending ratios of 0–5 %, the 4 mm nozzle yields the fastest combustion rate, while optimal ignition performance occurs with the 3 mm and 2 mm nozzles at hydrogen blending ratios of 10 % and 20 %, respectively. Decreasing nozzle diameter or hydrogen content shifts ignition from flame-induced to jet-induced. The combined effects of fuel reactivity and nozzle diameter define four combustion regimes: misfire, unstable combustion, rapid combustion, and slow combustion. Additionally, ignition delay is found to be largely insensitive to jet velocity under high-reactivity conditions.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138302"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An interfacially engineered Ni2P/Fe2P heterostructure grown on NiFe PBA/NF as a high-efficiency bifunctional electrocatalyst for overall water splitting","authors":"Pan Qu ,&nbsp;Zhenlu Zhao","doi":"10.1016/j.fuel.2026.138306","DOIUrl":"10.1016/j.fuel.2026.138306","url":null,"abstract":"<div><div>The development of high-performance, long-lasting bifunctional electrocatalysts is crucial for overall water splitting to drive the advancement of sustainable energy technology. In this study, we developed a Ni₂P/Fe₂P heterostructure composite catalyst supported on a NiFe Prussian blue analog (PBA) framework, designated Ni₂P/Fe₂P@NiFe PBA/NF, through sequential hydrothermal and phosphidation syntheses. The robust three-dimensional network formed by the in situ growth of Ni₂P/Fe₂P@NiFe PBA/NF on nickel foam provides integrated conduction pathways. This composite structure may facilitate electron conduction among the NF, Ni₂P/Fe₂P, and NiFe PBA. The heterojunction between Ni₂P and Fe₂P effectively accelerated electron transport, thereby achieving stable and efficient catalytic performance. Consequently, electrochemical tests in 1 M KOH demonstrated outstanding bifunctional activity, with overpotentials as low as 239 ± 5 mV for the oxygen evolution reaction (OER) and 174 ± 12 mV for the hydrogen evolution reaction (HER) at a current density of 100 mA cm⁻². The catalyst outperformed benchmark catalysts, such as RuO₂ and Pt/C, at high current densities and maintained significant stability after 100 h of continuous operation. Moreover, a two-electrode electrolyzer assembled with Ni₂P/Fe₂P@NiFe PBA/NF as both the anode and cathode exhibited excellent overall water-splitting performance, achieving a low cell voltage of 1.49 V at 10 mA cm⁻² along with remarkable stability exceeding 100 h.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138306"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Fischer-Tropsch Diesel and Polyoxymethylene dimethyl ether x blends spray combustion using multiple optical diagnostics","authors":"Min Xu,&nbsp;Xu Liu,&nbsp;Pengwei Wu,&nbsp;Huayang Sun,&nbsp;Zongqing Wang,&nbsp;Qian Wang","doi":"10.1016/j.fuel.2026.138272","DOIUrl":"10.1016/j.fuel.2026.138272","url":null,"abstract":"<div><div>Synthetic fuels (E-fuels) present notable advantages for high-load compression ignition (CI) engines, including improved performance and decreased reliance on fossil fuels. Blends of Fischer-Tropsch (F-T) Diesel and Polyoxymethylene dimethyl ether x (PODEx) are expected to integrate well with existing infrastructure while supporting efficient, low-emission combustion. The current study aims to provide comprehensive spray combustion data for E-fuel blends, laying the foundation for “’Fuel-Engine” co-optimization. Optical diagnostics of spray combustion were conducted under CI engine-relevant conditions for F-T Diesel and two blends—75 % F-T Diesel + 25 % PODEx by volume (F-T75/P25) and 50 % F-T Diesel + 50 % PODEx by volume (F-T50/P50). Results from various optical techniques demonstrate enhanced ignition and reduced soot formation in the blends compared to F-T Diesel, underscoring their promise for CI applications. Notably, the spray combustion flames of F-T75/P25 and F-T Diesel displayed similar CH₂O and OH structures, driven by diffusion flame chemistry that is alkane reaction-dominated. The flame structure of F-T50/P50, however, depended on the trade-off interaction between CH2O and OH. At low temperatures (750 K), an enrichment of CH₂O suppresses downstream high-temperature combustion. While for high temperature condition above 800 K, the OH structure is restored, leading to a substantial reduction in flame lift-off length. Additionally, in F-T50/P50, CH₂O and OH preferentially form HCO and CO rather than polycyclic aromatic hydrocarbons. Upon crossing the OH interface, HCO and CO will create a high-temperature layer downstream, likely linked to CO₂ formation.</div><div>Novelty and Significance.</div><div>This study presents the first comprehensive optical investigation into the spray combustion characteristics of F-T diesel blended PODEx under compression ignition engine-relevant conditions, revealing the coupling between alkane and ether combustion chemistries.</div><div>The novelty of this work lies in the discovery of a temperature-dependent “trade-off” mechanism between CH₂O and OH in E-fuel blends. Furthermore, we identify a distinct soot-free high-temperature reaction layer dominated by CO/HCO oxidation in high-ratio blends, providing a new understanding of how oxygenated blends alter the structure of diffusion flames. This research bridges the gap between macroscopic engine performance studies and fundamental chemical kinetics.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"413 ","pages":"Article 138272"},"PeriodicalIF":7.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}