Zhiqing Zhang , Zicheng He , Yanshuai Ye , Yuguo Wang , Chuan Liu , Yan Tan , Zibin Yin , Mingzhang Pan
{"title":"In-depth exploration of NH3-SCR over metal-based zeolite catalyst improvement research at low-temperature: Catalytic activity, sulfur/phosphorus resistance and hydrothermal stability","authors":"Zhiqing Zhang , Zicheng He , Yanshuai Ye , Yuguo Wang , Chuan Liu , Yan Tan , Zibin Yin , Mingzhang Pan","doi":"10.1016/j.fuproc.2026.108412","DOIUrl":"10.1016/j.fuproc.2026.108412","url":null,"abstract":"<div><div>Ammonia selective catalytic reduction (NH<sub>3</sub>-SCR) is the mainstream technology for controlling nitrogen oxide (NO<sub>x</sub>) emissions. However, the widespread application of zeolite catalysts faces multiple challenges: susceptibility to sulfur/phosphoru (S/P)-poisoning, narrow reaction temperature windows, and poor hydrothermal stability. This paper systematically reviews recent advances in metal zeolite catalysts, focusing on their low-temperature reaction mechanisms. Analysis addresses the aforementioned issues from two dimensions: (1) For Fe- and Cu-based monometallic catalysts, this study investigates the influence of active sites, framework Al, metal species migration, and acidity modification strategies on catalyst performance. (2) For composite metal catalysts, this study elucidates intermetallic electron transfer and synergistic effects within different frameworks, emphasizing the refinement of low-temperature reaction mechanisms and performance. It also supplements key techniques such as X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and brunauer emmett teller (BET) for SCR applications. The aim is to provide a theoretical foundation and research pathway for developing novel, highly efficient NH<sub>3</sub>-SCR catalysts, while proposing future research directions.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"284 ","pages":"Article 108412"},"PeriodicalIF":7.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mario Martín-Gamboa , Felipe Campos-Carriedo , Santiago Abelleira , Pedro L. Cruz , Christina Wulf , Javier Dufour , Diego Iribarren
{"title":"Prospective life cycle sustainability assessment and benchmarking of hydrogen from solid oxide electrolysis coupled with concentrated solar power","authors":"Mario Martín-Gamboa , Felipe Campos-Carriedo , Santiago Abelleira , Pedro L. Cruz , Christina Wulf , Javier Dufour , Diego Iribarren","doi":"10.1016/j.fuproc.2026.108417","DOIUrl":"10.1016/j.fuproc.2026.108417","url":null,"abstract":"<div><div>Achieving sustainable hydrogen systems requires balancing environmental, economic and social aspects. In this regard, research on the life-cycle sustainability of emerging pathways such as solid oxide electrolysis (SOE) coupled with concentrated solar power (CSP) remains limited. This study presents a prospective life cycle sustainability assessment (LCSA) of hydrogen production via SOE coupled with CSP, benchmarked against hydrogen from steam methane reforming (SMR) as a conventional counterpart. By following the latest guidelines for LCSA of hydrogen-related systems developed within the SH2E project, this study applies consistent methodological choices across sustainability dimensions (e.g. functional unit definition), while transparently addressing model asymmetries. Results highlight notable differences in hotspots across dimensions and indicators. The CSP section dominates environmental impacts due to high material demand, while economic hotspots additionally include electrolysers and operational wages. Social impacts are primarily linked to the high relative share of worker hours in the Spanish hydrogen production facility itself, with added supply chain risks associated with chromium extraction in Kazakhstan and natural gas sourcing from Algeria. Even though conventional hydrogen from SMR outperforms hydrogen from SOE in four out of seven sustainability indicators, the latter offers promising results in terms of lower carbon footprint, reduced fair salary risk, and enhanced prospects for economic growth. Overall, these findings highlight the potential of SOE to contribute to a sustainable hydrogen economy, while they also stress areas (e.g. cost competitiveness, resource efficiency, and supply chain risk management) where sustainable-by-design research is essential to mitigate burden-shifting across impact categories and sustainability dimensions.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"284 ","pages":"Article 108417"},"PeriodicalIF":7.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sachin K.S. , David Pallarès , Bo Leckner , Pratikash Panda , R.V. Ravikrishna
{"title":"Fluidized bed combustion characteristics of high-ash coal char under O2/H2O and O2/CO2/H2O environments","authors":"Sachin K.S. , David Pallarès , Bo Leckner , Pratikash Panda , R.V. Ravikrishna","doi":"10.1016/j.fuproc.2026.108415","DOIUrl":"10.1016/j.fuproc.2026.108415","url":null,"abstract":"<div><div>The combustion characteristics of a batch of in-situ prepared high-ash coal char have been investigated under different fluidized bed operating conditions (i.e. O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> concentration, balance gas, bed temperature, particle size) in an optically accessible fluidized bed. A fast Universal Exhaust Gas Oxygen (UEGO) sensor measured the oxygen partial pressure at the exhaust to determine the reaction rate and burnout time of char particles, which demonstrates a novel application of this type of sensor in high H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O (wet) environments. A pre-calibrated two-colour pyrometry technique was employed to measure the temperature of char particles. The effect of the oxyfuel atmosphere on the burnout time of char particles was found to be prominent at higher bed temperatures, lower O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> concentrations, and larger particle sizes. The sensitivity of combustion behaviour to variations in the combustion environment was higher for larger particle size. Results show that the burnout time was the lowest in O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O for both 1.2 mm and 3 mm particle sizes. This was attributed to the higher diffusivity of O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> in H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O and the H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O gasification reaction. The addition of H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O to O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> environment enhanced the diffusivity of O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, making it comparable to that in N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. In 10% O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/45% CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/45% H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O environment, competitive interactions among O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O were more pronounced for smaller particles. The reactivity of char in 10% O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/90% H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O at higher bed temperat","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"284 ","pages":"Article 108415"},"PeriodicalIF":7.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A density functional theory study of CH4 oxidation over LaMnO3 oxygen carrier during chemical looping combustion","authors":"Zhongze Bai , Kai H. Luo","doi":"10.1016/j.fuproc.2026.108418","DOIUrl":"10.1016/j.fuproc.2026.108418","url":null,"abstract":"<div><div>LaMnO<sub>3</sub>-based oxygen carriers (OCs) are considered a promising class of materials for chemical looping combustion (CLC); however, elucidating their detailed microscopic reaction mechanisms remains challenging. In this study, density functional theory (DFT) calculations were employed to investigate the reaction mechanisms of CH<sub>4</sub> combustion on the LaMnO<sub>3</sub>(010) surface. The results reveal that CH<sub>4</sub> weakly adsorbs with negligible charge transfer, whereas CH<sub>x</sub> species (x = 0–3) exhibit strong chemisorption, which strengthens as hydrogen atoms are removed. The CH → C + H step is identified as the rate-limiting step during CH<sub>4</sub> dehydrogenation, featuring an energy barrier of 2.233 eV. For CO<sub>2</sub> formation, the adsorbed carbon atom (C*) reacts first with O<sub>1</sub> (the first lattice oxygen atom) to form CO*, which then reacts with O<sub>2</sub> (the second lattice oxygen atom) to produce CO<sub>2</sub>*, followed by desorption, with an overall energy barrier of 1.693 eV. H<sub>2</sub>O formation occurs via surface hydrogen reacting with lattice O<sub>1</sub>, forming H<sub>2</sub>O* at the O<sub>v1</sub> (the vacancy formed by O<sub>1</sub> removal) site prior to desorption, with an energy barrier of 1.465 eV. Overall, CH<sub>4</sub> dehydrogenation governs the reaction kinetics, while surface oxygen is critical for enabling complete oxidation to CO<sub>2</sub> and H<sub>2</sub>O. This study provides fundamental insights into CH<sub>4</sub> oxidation on LaMnO<sub>3</sub>(010), which may guide the design of novel OCs in the future.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"284 ","pages":"Article 108418"},"PeriodicalIF":7.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rabia Qammar , Muhammad Bilal Yaseen , Rana Zain Ul Abidin , Sadashiv Chaturvedi
{"title":"HydroStor-PMX: A multi-phase hybrid system for high-density hydrogen storage via pressure-modulated MXene frameworks","authors":"Rabia Qammar , Muhammad Bilal Yaseen , Rana Zain Ul Abidin , Sadashiv Chaturvedi","doi":"10.1016/j.fuproc.2026.108409","DOIUrl":"10.1016/j.fuproc.2026.108409","url":null,"abstract":"<div><div>The study proposes a new kind of multi-phase hybrid energy-storage device, namely HydroStor-PMX, in which pressure-modulated MXene structures are combined with a pressure-based machine learning optimization algorithm to create a pressure-induced hydrogen storage process with unprecedented results. The new method provides a combination of two-dimensional MXene materials (<span><math><mi>T</mi><msub><mi>i</mi><mn>3</mn></msub><mspace></mspace><msub><mi>C</mi><mn>2</mn></msub><mspace></mspace><msub><mi>T</mi><mi>x</mi></msub><mo>,</mo><msub><mi>V</mi><mn>2</mn></msub><mspace></mspace><mi>C</mi><msub><mi>T</mi><mi>x</mi></msub><mo>,</mo><mi>M</mi><msub><mi>o</mi><mn>2</mn></msub><mspace></mspace><mi>C</mi><msub><mi>T</mi><mi>x</mi></msub><mspace></mspace></math></span>) with dynamic pressure modulation methodologies that allow optimization of interlayer distances and binding energies occurring in real time. In depth density functional theory calculations indicate the optimum binding energies of hydrogen bonded as 28.5 to 49.7 kJ/mol <span><math><msub><mi>H</mi><mn>2</mn></msub></math></span> which can be stored in reversible form under ambient temperature and pressure. Ensemble models of machine learning allow obtaining excellent predictive performance. Experimental confirmation of breakthrough performance can be seen with hydrogen storage capacities as high as 8.5 wt% at moderate pressure (50 bar) and room temperature (25C), and which is 150% better than static MXene systems with rapid kinetics (8.9 min to 90% capacity). It is quite stable as long term cyclability testing shows that less than 5% of its capacity lost during the same charge-discharge cycles of 5000.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108409"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-quality biochar from the catalytic pyrolysis of Brachychiton seeds: Optimization and characterization","authors":"Anass Choukoud , Hammadi El Farissi , Lokmane Abdelouahed , Abdesselam Tahani , Abdelmonaem Talhaoui","doi":"10.1016/j.fuproc.2026.108410","DOIUrl":"10.1016/j.fuproc.2026.108410","url":null,"abstract":"<div><div>This study aims to describe the effect of pyrolysis conditions (temperature, particle size,<!--> <!-->and type of catalyst) on the production of biochar from Brachychiton seeds. Pyrolysis experiments were conducted at between 300 °C–550 °C with particle sizes from <315 μm to 800–1600 μm and catalysts including Al₂O₃, CaO, H<sub>3</sub>BO<sub>3</sub>, ZrO(NO<sub>3</sub>)<sub>2</sub>, V₂O₅, ZnO, Fe₂O₃, and TiO₂. The results showed that the temperature range from maximum biochar yield was 400 °C and smaller particle (smaller than <315 μm) showed higher biochar yield.Char yield was significantly improved by Al<sub>2</sub>O<sub>3</sub> even at low temperatures while higher catalyst concentration led to an increased yield till 2%<!--> <!-->catalyst. Biochar had alkaline pH values, varying from 7.81 to 9.80,<!--> <!-->making them suitable as soil ameliorants. Electrical conductivity ranged from 308 μS.cm<sup>−1</sup> to 1650 μS.cm<sup>−1</sup> with the effect of temp and catalyst type measured, demonstrating ranges of ion concentrations<!--> <!-->available for agricultural application. ATR-IR analysis also revealed a decrease in the concentration of functional groups such as OH, C<img>H and C<img>O, signifying a conversion of the original biomass to more aromatic species with increasing temperature. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and elemental analyses indicate a remarkable change in the surface morphology as well as the composition of biochars, such as increased pore volume, the formation of numerous mineral phases and the successful incorporation of catalysts. Notably, TiO₂, H₃BO₃ and Fe₂O₃ are effective in enhancing their calorific value, which reaches 49.464 MJ.kg-<sup>1</sup>. The results highlight the importance of biochar pyrolysis conditions for improving their properties for energy, environmental and agricultural use.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108410"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Techno-economic analysis of waste-to-SAF pathways with carbon capture and storage and green hydrogen integrations","authors":"Mohammad A. Rasheed, Massimiliano Materazzi","doi":"10.1016/j.fuproc.2026.108416","DOIUrl":"10.1016/j.fuproc.2026.108416","url":null,"abstract":"<div><div>De-fossilising the aviation sector is essential for global climate goals, with sustainable aviation fuels (SAF) identified as a key low-emission solution. Municipal solid waste (MSW), when converted to refuse-derived fuel (RDF), offers an abundant, largely biogenic feedstock for SAF production while diverting waste from landfills. This research study analyses the production of SAF from RDF gasification via bioenergy with carbon capture and storage (BECCS) and power biomass to liquid (PBtL) concepts with Fischer-Tropsch (FT) and Methanol-to-Jet (MTJ) fuel syntheses as production pathways. The processes are modelled within Aspen Plus and single process units are validated against industrial plant data. In the BECCS route, 95% of carbon dioxide (CO₂) is captured post-syngas conditioning and permanently sequestered, enabling potential negative emissions and carbon credits. The PBtL route integrates green hydrogen from water electrolysis for syngas conditioning, with the electrolytic oxygen supporting gasification and reforming. Results show that integrating green H₂ boosts SAF yield but increases energy demand. The MTJ-H<sub>2</sub> pathway demonstrated the lowest levelized cost of production of £7.7/kg SAF, although this is still higher than conventional jet fuel and thus not competitive within the current market. As such, policy frameworks and economic incentives remain essential to achieve large-scale deployment of SAF.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108416"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hossein Hassanzadeh , Reza Abedini , Amir Mosayebi
{"title":"Combined steam and CO2 reforming of ethanol over Ni–Cu/ZrO2 catalyst: Experimental and statistical optimization for sustainable syngas and hydrogen production","authors":"Hossein Hassanzadeh , Reza Abedini , Amir Mosayebi","doi":"10.1016/j.fuproc.2026.108408","DOIUrl":"10.1016/j.fuproc.2026.108408","url":null,"abstract":"<div><div>The combined steam and CO<sub>2</sub> reforming of ethanol (CSCRE) is a promising route for sustainable syngas and hydrogen production, enabling simultaneous utilization of renewable ethanol and CO<sub>2</sub>. In this study, a bimetallic Ni–Cu/ZrO<sub>2</sub> catalyst was synthesized and evaluated for the CSCRE reaction through an integrated approach combining catalyst characterization, long-term stability testing, and statistical process optimization. Structural and redox characterization (XRD, BET, H<sub>2</sub>-TPR, TEM, Raman, and TGA) revealed that Cu incorporation enhances Ni dispersion, improves reducibility, and suppresses sintering and carbon deposition. Response surface methodology (RSM) was employed to investigate the effects of temperature, CO<sub>2</sub>/H<sub>2</sub>O ratio, and (CO<sub>2</sub> + H<sub>2</sub>O)/ethanol ratio on ethanol and CO<sub>2</sub> conversions, syngas yields, and H<sub>2</sub>/CO ratio. Reaction temperature was identified as the dominant parameter influencing conversions and product yields, while the CO<sub>2</sub>/H<sub>2</sub>O ratio effectively tuned syngas composition. Under the optimized conditions (900 °C, CO<sub>2</sub>/H<sub>2</sub>O = 2, (CO<sub>2</sub> + H<sub>2</sub>O)/ethanol = 2), the Ni–Cu/ZrO<sub>2</sub> catalyst exhibited high ethanol and CO<sub>2</sub> conversions (>90%) and maintained stable activity for approximately 950 min, followed by only moderate deactivation during prolonged operation. The stability tests demonstrated that Ni–Cu/ZrO<sub>2</sub> consistently outperforming monometallic Ni/ZrO<sub>2</sub> under the different operating conditions. These results highlight the importance of both catalyst design and operating condition optimization in achieving high performance and sustained stability in CSCRE processes.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108408"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongyu Zhao , Pan Wang , Lili Lei , Zonglin Li , Xuteng Zhao , He Lin
{"title":"Evolution of the hydrothermal aging mechanism in Ni/CeO2 catalysts for N2O decomposition based on surface effect","authors":"Hongyu Zhao , Pan Wang , Lili Lei , Zonglin Li , Xuteng Zhao , He Lin","doi":"10.1016/j.fuproc.2026.108407","DOIUrl":"10.1016/j.fuproc.2026.108407","url":null,"abstract":"<div><div>The utilization of Ni/CeO<sub>2</sub> catalysts for direct catalytic decomposition of N<sub>2</sub>O represents a promising technological pathway to mitigate N<sub>2</sub>O emissions from ammonia-fueled combustion. This study investigated the influence of Ni doping on the N<sub>2</sub>O decomposition process over both fresh and hydrothermal aging CeO<sub>2</sub> catalysts through simulated gas test bench. By combining comprehensive physicochemical characterization with DFT calculations, the hydrothermal aging mechanism underlying the deterioration of catalytic activity and physicochemical properties in Ni/CeO<sub>2</sub> catalysts was elucidated. The findings revealed that hydrothermal aging was accompanied by crystallite growth and textural deterioration. Further, hydrothermal aging altered the crystal structure of Ni/CeO<sub>2</sub> via edge/corner truncation, resulting in a decreased Ce<sup>3+</sup>/Ce<sup>4+</sup> ratio, an increased O<sub>II</sub>/O<sub>I</sub> ratio, and consequently, a reduction in the comprehensive combustion index (<em>S</em>) and combustion stability index (<em>R</em><sub>w</sub>) for N<sub>2</sub>O decomposition. Ni doping was found to modify the catalytic activity of CeO<sub>2</sub> by regulating the adsorption energies of N<sub>2</sub>O and H<sub>2</sub>O molecules on low-Miller-index surfaces. The Gibbs free energy changes induced by H<sub>2</sub>O adsorption on these low-index surfaces (153.6 °C → 430.2 °C → 531.4 °C) were identified as the primary cause for the directional surface migration of CeO<sub>2</sub>, which ultimately led to the degradation of the catalytic activity of Ni/CeO<sub>2</sub> catalysts.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108407"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of flue gas recirculation on the formation of unburned hydrocarbons in oxy-fuel and air flames in a semi-industrial scale burner","authors":"D. König, D. Hülsbruch, J. Ströhle, B. Epple","doi":"10.1016/j.fuproc.2026.108413","DOIUrl":"10.1016/j.fuproc.2026.108413","url":null,"abstract":"<div><div>Oxy-fuel combustion is a promising technology for reducing CO<sub>2</sub> emissions in the energy sector. In this process, nitrogen from air is replaced with CO<sub>2</sub>, to ensure the purity of CO<sub>2</sub> in the flue gas, altering the properties of the oxidizer. For industrial applications, different methods of supplying CO<sub>2</sub> for the combustion are possible, typically categorized into different recirculation pathways: These include recirculation pathways with higher moisture and minority species content as well as a recirculation of cleaned flue gas after the scrubbing stages of the plant. These approaches differ primarily in oxidizer temperature, the amount of H<sub>2</sub>O present in the oxidizer stream and the occurrence of minority species. However, the presence of H<sub>2</sub>O in the combustion environment influences the gasification mechanisms within the flame, similar to the effects of CO<sub>2</sub>. This paper compares the formation and presence of unburned hydrocarbons between a conventional air flame and two oxy-fuel combustion cases, one using a mixture of synthetic CO<sub>2</sub> and O<sub>2</sub> and the other incorporating flue gas recirculation. Analyzing these intermediate species in the different flames, features a significant insight into the combustion chemistry and can be used as validation data for a detailed Computational Fluid Dynamics (CFD) and kinetic modeling of this process. This comparison for the same flame leads to increased knowledge about the differences between synthetic oxy-fuel combustion and flue gas recirculation and is a novelty in the field of semi-industrial oxy-fuel combustion. For the experiments, milled walnut shells are used as fuel. Comparing air and oxy-fuel combustion, the oxy-fuel flames shows significantly higher unburned hydrocarbons in the flame. However, the results indicate that differences in unburned hydrocarbon formation between the two oxy-fuel cases become apparent only at greater distances from the burner inlet, which is attributed to higher oxidizer inlet temperatures, adiabatic flame temperature, and increased H<sub>2</sub>O content in the oxy-fuel case with flue gas recirculation. This leads to increased hydrocarbons present in the end of the synthetic oxy-fuel case.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"283 ","pages":"Article 108413"},"PeriodicalIF":7.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}