Pub Date : 2025-09-17DOI: 10.1016/j.fuproc.2025.108335
Bin Sun , Xiwei Ye , Yongsheng Guo , Shu Yan , Wenjun Fang
Turbulent flow in high-speed hydrocarbon fuels increases engine resistance and pump load, leading to higher power demands and reduced reliability. Current drag reduction agents often worsen heat transfer performance. To overcome the contradiction between drag reduction and heat transfer deterioration, comb-type ternary block copolymers, hexadecyl methacrylate-co-dimethylaminoethyl methacrylate-co-methacrylic acid, have been designed and synthesized through photoinitiated polymerization and used as emulsifiers to prepare emulsified fuels. The emulsions with different compositions of JP-10 to water as 9.5:0.5, 9:1, 8.5:1.5, and 8:2, respectively, were characterized using creaming index analysis, dynamic light scattering and zeta potential measurements, rheological analysis, laser scanning confocal microscopy and polarized optical microscopy measurements, interfacial tension and interfacial film rheology measurements. A significant enhancement in heat sink and heat transfer coefficients of the emulsified fuel compared to pure JP-10 is observed within the temperature range from 100 to 225 °C. Simultaneous enhancements in drag reduction rate and heat transfer coefficient for the emulsified fuel in a distributed flow calorimeter can reach 19.5 % and 6.09 %, respectively. Emulsified fuels show great prospects in improving the stable and highly efficient operation of advanced aircraft.
{"title":"Emulsified fuel stabilized by comb-type ternary block copolymers for drag reduction and heat transfer enhancement","authors":"Bin Sun , Xiwei Ye , Yongsheng Guo , Shu Yan , Wenjun Fang","doi":"10.1016/j.fuproc.2025.108335","DOIUrl":"10.1016/j.fuproc.2025.108335","url":null,"abstract":"<div><div>Turbulent flow in high-speed hydrocarbon fuels increases engine resistance and pump load, leading to higher power demands and reduced reliability. Current drag reduction agents often worsen heat transfer performance. To overcome the contradiction between drag reduction and heat transfer deterioration, comb-type ternary block copolymers, hexadecyl methacrylate-co-dimethylaminoethyl methacrylate-co-methacrylic acid, have been designed and synthesized through photoinitiated polymerization and used as emulsifiers to prepare emulsified fuels. The emulsions with different compositions of JP-10 to water as 9.5:0.5, 9:1, 8.5:1.5, and 8:2, respectively, were characterized using creaming index analysis, dynamic light scattering and zeta potential measurements, rheological analysis, laser scanning confocal microscopy and polarized optical microscopy measurements, interfacial tension and interfacial film rheology measurements. A significant enhancement in heat sink and heat transfer coefficients of the emulsified fuel compared to pure JP-10 is observed within the temperature range from 100 to 225 °C. Simultaneous enhancements in drag reduction rate and heat transfer coefficient for the emulsified fuel in a distributed flow calorimeter can reach 19.5 % and 6.09 %, respectively. Emulsified fuels show great prospects in improving the stable and highly efficient operation of advanced aircraft.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108335"},"PeriodicalIF":7.7,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106197","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}
Pub Date : 2025-09-16DOI: 10.1016/j.fuproc.2025.108336
Bernardo A. Souto, Justice Asomaning, David C. Bressler
This study investigates radical-driven deoxygenation mechanisms during the non-catalytic pyrolysis of saturated and unsaturated carboxylic acids. Pyrolysis experiments were conducted at 410 °C, between 0.5 and 2 h, using carboxylic acids of varying carbon chain lengths (C6 to C18) and saturation levels, along with ketones. Feedstock conversion and deoxygenation products were quantified using GC–MS/FID for liquids and GC-TCD/FID for gases. Results demonstrated that carboxylic acid chain length significantly influences pyrolysis behavior, with significant differences in deoxygenation pathway linked to acid chain length and saturation level. Decarboxylation was the predominant pathway for short-chain carboxylic acids, whereas long-chain acids showed increased tendency towards decarbonylation. Short-chain saturated carboxylic acids favoured ketonic decarboxylation during the initial stages of pyrolysis, resulting in notable amounts of ketones and carbon dioxide. Subsequent decarbonylation of these ketones contributed to further deoxygenation, generating hydrocarbons and shorter-chain ketones via radical-driven mechanisms. In contrast unsaturated carboxylic acids underwent extensive cracking, which suppressed ketonic decarboxylation and led to reduced overall hydrocarbon yields. Additionally, mixed carboxylic acid feedstocks showed decreased conversion efficiencies, primarily due to limited intermolecular interactions necessary for effective ketonic decarboxylation. This work explores radical-driven, non-catalytic pyrolysis of fatty acids, providing a detailed mechanistic understanding of how chain length and saturation influence reaction pathway. The findings highlight key determinants of product selectivity and deoxygenation efficiency, providing valuable insights for optimizing feedstock compositions in pyrolysis-based sustainable biofuel production.
{"title":"Influence of chain length and saturation on carboxylic acid pyrolysis mechanisms","authors":"Bernardo A. Souto, Justice Asomaning, David C. Bressler","doi":"10.1016/j.fuproc.2025.108336","DOIUrl":"10.1016/j.fuproc.2025.108336","url":null,"abstract":"<div><div>This study investigates radical-driven deoxygenation mechanisms during the non-catalytic pyrolysis of saturated and unsaturated carboxylic acids. Pyrolysis experiments were conducted at 410 °C, between 0.5 and 2 h, using carboxylic acids of varying carbon chain lengths (C6 to C18) and saturation levels, along with ketones. Feedstock conversion and deoxygenation products were quantified using GC–MS/FID for liquids and GC-TCD/FID for gases. Results demonstrated that carboxylic acid chain length significantly influences pyrolysis behavior, with significant differences in deoxygenation pathway linked to acid chain length and saturation level. Decarboxylation was the predominant pathway for short-chain carboxylic acids, whereas long-chain acids showed increased tendency towards decarbonylation. Short-chain saturated carboxylic acids favoured ketonic decarboxylation during the initial stages of pyrolysis, resulting in notable amounts of ketones and carbon dioxide. Subsequent decarbonylation of these ketones contributed to further deoxygenation, generating hydrocarbons and shorter-chain ketones via radical-driven mechanisms. In contrast unsaturated carboxylic acids underwent extensive cracking, which suppressed ketonic decarboxylation and led to reduced overall hydrocarbon yields. Additionally, mixed carboxylic acid feedstocks showed decreased conversion efficiencies, primarily due to limited intermolecular interactions necessary for effective ketonic decarboxylation. This work explores radical-driven, non-catalytic pyrolysis of fatty acids, providing a detailed mechanistic understanding of how chain length and saturation influence reaction pathway. The findings highlight key determinants of product selectivity and deoxygenation efficiency, providing valuable insights for optimizing feedstock compositions in pyrolysis-based sustainable biofuel production.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108336"},"PeriodicalIF":7.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106191","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}
Pub Date : 2025-09-16DOI: 10.1016/j.fuproc.2025.108338
Byung Sun Yoon , Ki Cheol Kim , Min-Jae Kim , Jae-Rang Youn , Mincheol Kim , Taesung Jung , Sang Goo Jeon , Woohyun Kim , Chang Hyun Ko
Catalytic methane decomposition (CMD) is a promising reaction for CO2-free hydrogen production, as it generates no CO2 emissions and produces solid carbon byproducts. However, catalyst deactivation due to carbon accumulation necessitates the development of catalysts with high activity, stability, and high capacity for carbon products. In this study, Ce-promoted Ni/Al2O3 catalysts were synthesized with varying Ce loadings to investigate the role of Ce in enhancing catalyst performance. The addition of Ce was found to weaken the interaction between Ni and Al2O3, thereby increasing the surface concentration of metallic Ni0 and improving catalytic activity. Nevertheless, excessive Ce loading resulted in performance deterioration, primarily due to a significant reduction in mesoporous volume. This loss of physical space limited the growth of carbon products and hindered catalyst effectiveness. The results highlight the need to balance the promotional effects of Ce with the preservation of pore structure to optimize catalyst design for CMD.
{"title":"Production of CO2-free hydrogen via catalytic methane decomposition over Ce-promoted Ni/Al2O3 catalysts","authors":"Byung Sun Yoon , Ki Cheol Kim , Min-Jae Kim , Jae-Rang Youn , Mincheol Kim , Taesung Jung , Sang Goo Jeon , Woohyun Kim , Chang Hyun Ko","doi":"10.1016/j.fuproc.2025.108338","DOIUrl":"10.1016/j.fuproc.2025.108338","url":null,"abstract":"<div><div>Catalytic methane decomposition (CMD) is a promising reaction for CO<sub>2</sub>-free hydrogen production, as it generates no CO<sub>2</sub> emissions and produces solid carbon byproducts. However, catalyst deactivation due to carbon accumulation necessitates the development of catalysts with high activity, stability, and high capacity for carbon products. In this study, Ce-promoted Ni/Al<sub>2</sub>O<sub>3</sub> catalysts were synthesized with varying Ce loadings to investigate the role of Ce in enhancing catalyst performance. The addition of Ce was found to weaken the interaction between Ni and Al<sub>2</sub>O<sub>3</sub>, thereby increasing the surface concentration of metallic Ni<sup>0</sup> and improving catalytic activity. Nevertheless, excessive Ce loading resulted in performance deterioration, primarily due to a significant reduction in mesoporous volume. This loss of physical space limited the growth of carbon products and hindered catalyst effectiveness. The results highlight the need to balance the promotional effects of Ce with the preservation of pore structure to optimize catalyst design for CMD.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108338"},"PeriodicalIF":7.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096570","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}
Pub Date : 2025-09-16DOI: 10.1016/j.fuproc.2025.108332
Jie Zhang , Hulin Li , Hao Chen , Hong Zhang , Chuang Yang , Haobo Li
As an inherent by-product of the petroleum industry, oily sludge has substantial potential as energy resource due to its high oil content and calorific value. The hydrodenitrogenation/hydrodesulfurization of nitrogen/sulfur compounds quinoline and thiophene in oily sludge at sub/supercritical hydrothermal conditions was studied, along with its catalytic properties and reaction mechanism. The effects of nickel-based catalysts, hydrogen sources, and reaction conditions on hydrodenitrogenation (HDN) of quinoline were examined. A reaction kinetic model for quinoline in supercritical water was developed. An experimental investigation on hydrodesulfurization (HDS) of sulfur-containing thiophene was conducted, and the catalytic properties of nickel-based catalysts for simultaneous HDN and HDS of quinoline and thiophene were evaluated. Within 400–440 °C, ethanol was superior to formic acid as hydrogen source. Ni-Co/γ-Al2O3 had the most effective catalytic impact on denitrogenation of quinoline. The conversion efficiency of 5 wt% quinoline reached 94.67 %, while denitrogenation efficiency was 57.08 % at 24 MPa, 440 °C, and 60 min. The hydrogenation and ring-opening steps had significant effects on the overall denitrogenation process. The hydrodesulfurization catalysis from Ni-Mo/γ-Al2O3 was the most prominent for thiophene. At 24 MPa, 440 °C, and 60 min, the desulfurization efficiency of thiophene reached 57.34 %. Desulfurization of thiophene mainly followed the hydrogenation route, with thiophene rings being saturated before desulfurization occurred.
{"title":"Hydrothermal hydrodenitrogenation and hydrodesulfurization over nickel-based catalysts in sub/supercritical water","authors":"Jie Zhang , Hulin Li , Hao Chen , Hong Zhang , Chuang Yang , Haobo Li","doi":"10.1016/j.fuproc.2025.108332","DOIUrl":"10.1016/j.fuproc.2025.108332","url":null,"abstract":"<div><div>As an inherent by-product of the petroleum industry, oily sludge has substantial potential as energy resource due to its high oil content and calorific value. The hydrodenitrogenation/hydrodesulfurization of nitrogen/sulfur compounds quinoline and thiophene in oily sludge at sub/supercritical hydrothermal conditions was studied, along with its catalytic properties and reaction mechanism. The effects of nickel-based catalysts, hydrogen sources, and reaction conditions on hydrodenitrogenation (HDN) of quinoline were examined. A reaction kinetic model for quinoline in supercritical water was developed. An experimental investigation on hydrodesulfurization (HDS) of sulfur-containing thiophene was conducted, and the catalytic properties of nickel-based catalysts for simultaneous HDN and HDS of quinoline and thiophene were evaluated. Within 400–440 °C, ethanol was superior to formic acid as hydrogen source. Ni-Co/γ-Al<sub>2</sub>O<sub>3</sub> had the most effective catalytic impact on denitrogenation of quinoline. The conversion efficiency of 5 wt% quinoline reached 94.67 %, while denitrogenation efficiency was 57.08 % at 24 MPa, 440 °C, and 60 min. The hydrogenation and ring-opening steps had significant effects on the overall denitrogenation process. The hydrodesulfurization catalysis from Ni-Mo/γ-Al<sub>2</sub>O<sub>3</sub> was the most prominent for thiophene. At 24 MPa, 440 °C, and 60 min, the desulfurization efficiency of thiophene reached 57.34 %. Desulfurization of thiophene mainly followed the hydrogenation route, with thiophene rings being saturated before desulfurization occurred.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108332"},"PeriodicalIF":7.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106198","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}
Pub Date : 2025-09-12DOI: 10.1016/j.fuproc.2025.108329
Yueming Liu, Shuqin Liu, Zihe Liu, Xuan Li, Jiahong Cao, Chuan Qi, Weibin Wang
Underground coal gasification (UCG) is one of the important ways for in-situ clean conversion of deep coal resources. Affected by groundwater influx, steam gasification becomes the dominant reaction for syngas production in the UCG process. This paper investigates the pressurized gas production characteristics of semi-coke under steam atmosphere range from atmospheric to 3 MPa. The gasified residual coke is characterized by N2 adsorption-desorption, SEM, AFM, and Raman spectroscopy to analyze the evolution of pore structure and functional groups of semi-coke with changes in pressure and carbon conversion rate. The results show that the action of steam leads to the development of abundant microporous structures below 1 nm on the semi-coke surface. Under 3 MPa, the specific surface area of micropores increases from 17.64 m2/g to 435.46 m2/g, which is 4 times that under CO₂ atmosphere. Micropores serve as the main site for the initial reaction of steam gasification. Evolution of semi-coke structure based on functional groups is the result of competition between pressure-dominated chain scission and H radical-dominated polycondensation. The research results provide a theoretical basis for strengthening the hydrogen production process of deep underground coal gasification affected by groundwater.
{"title":"Pore structure evolution of semi-coke under steam atmosphere in the context of deep underground coal gasification","authors":"Yueming Liu, Shuqin Liu, Zihe Liu, Xuan Li, Jiahong Cao, Chuan Qi, Weibin Wang","doi":"10.1016/j.fuproc.2025.108329","DOIUrl":"10.1016/j.fuproc.2025.108329","url":null,"abstract":"<div><div>Underground coal gasification (UCG) is one of the important ways for in-situ clean conversion of deep coal resources. Affected by groundwater influx, steam gasification becomes the dominant reaction for syngas production in the UCG process. This paper investigates the pressurized gas production characteristics of semi-coke under steam atmosphere range from atmospheric to 3 MPa. The gasified residual coke is characterized by N<sub>2</sub> adsorption-desorption, SEM, AFM, and Raman spectroscopy to analyze the evolution of pore structure and functional groups of semi-coke with changes in pressure and carbon conversion rate. The results show that the action of steam leads to the development of abundant microporous structures below 1 nm on the semi-coke surface. Under 3 MPa, the specific surface area of micropores increases from 17.64 m<sup>2</sup>/g to 435.46 m<sup>2</sup>/g, which is 4 times that under CO₂ atmosphere. Micropores serve as the main site for the initial reaction of steam gasification. Evolution of semi-coke structure based on functional groups is the result of competition between pressure-dominated chain scission and H radical-dominated polycondensation. The research results provide a theoretical basis for strengthening the hydrogen production process of deep underground coal gasification affected by groundwater.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108329"},"PeriodicalIF":7.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044873","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}
Pub Date : 2025-09-11DOI: 10.1016/j.fuproc.2025.108327
Fengtian Bai , Clement N. Uguna , Will Meredith , Colin E. Snape , Christopher H. Vane , Chenggong Sun
Understanding kerogen transformation under geological conditions is critical for optimizing the in-situ conversion (ISC) process of organic-rich unconventional resources. Sequential high-pressure hydrous pyrolysis was employed to investigate the geological thermal evolution and hydrocarbon generation mechanisms of organic matter in immature Huadian (Type II1 kerogen) and Fushun (Type I kerogen) shales. Experiments progressed through four thermal stages, that is Stage 1 (350 °C, 6 h), Stage 2 (350 °C, 24 h), Stage 3 (380 °C, 24 h), and Stage 4 (420 °C, 24 h), with comprehensive analysis of hydrocarbon products by gas-chromatography mass-spectrometry and solid residues by vitrinite reflectance (Ro) and Rock-Eval pyrolysis. The results revealed that the hydrocarbon-generation potential of these two shales declined sharply with a Ro of 0.78–1.23 %, correlating with peak oil generation. Type I kerogen (Fushun) exhibited higher reactivity, generating twice the cumulative oil yield (normalized by TOC) compared to Type II1 (Huadian) and transitioning earlier to oil dominance. Biomarker evolution (OEP decline, sterane/hopane isomerization) in expelled oil and declining gas dryness index (C1/ΣC1–C5) correlated strongly with the maturity of organic matter, enabling non-destructive ISC monitoring. Compared to typical temperatures used in ex-situ retorting (520 °C), the kerogen conversion was completed at lower temperatures of 350–420 °C in this study, validating prolonged heating as a viable low-energy ISC strategy. However, high-pressure conditions in geological formations may impede hydrocarbon expulsion efficiency, leading to the retention of viscous bitumen and thus necessitating engineered solutions for effective oil recovery. This research enriches the understanding of high-pressure pyrolysis mechanisms of immature/low-maturity unconventional resources and establishes a geochemical framework for optimizing ISC in recovering the oil from these source rocks, ultimately contributing to advancing sustainable exploitation of unconventional resources.
{"title":"Thermal evolution and hydrocarbon generation of organic matter in shales via sequential high-pressure hydrous pyrolysis: Implications for in-situ conversion of unconventional resource","authors":"Fengtian Bai , Clement N. Uguna , Will Meredith , Colin E. Snape , Christopher H. Vane , Chenggong Sun","doi":"10.1016/j.fuproc.2025.108327","DOIUrl":"10.1016/j.fuproc.2025.108327","url":null,"abstract":"<div><div>Understanding kerogen transformation under geological conditions is critical for optimizing the in-situ conversion (ISC) process of organic-rich unconventional resources. Sequential high-pressure hydrous pyrolysis was employed to investigate the geological thermal evolution and hydrocarbon generation mechanisms of organic matter in immature Huadian (Type II<sub>1</sub> kerogen) and Fushun (Type I kerogen) shales. Experiments progressed through four thermal stages, that is Stage 1 (350 °C, 6 h), Stage 2 (350 °C, 24 h), Stage 3 (380 °C, 24 h), and Stage 4 (420 °C, 24 h), with comprehensive analysis of hydrocarbon products by gas-chromatography mass-spectrometry and solid residues by vitrinite reflectance (Ro) and Rock-Eval pyrolysis. The results revealed that the hydrocarbon-generation potential of these two shales declined sharply with a Ro of 0.78–1.23 %, correlating with peak oil generation. Type I kerogen (Fushun) exhibited higher reactivity, generating twice the cumulative oil yield (normalized by TOC) compared to Type II<sub>1</sub> (Huadian) and transitioning earlier to oil dominance. Biomarker evolution (OEP decline, sterane/hopane isomerization) in expelled oil and declining gas dryness index (C<sub>1</sub>/ΣC<sub>1</sub>–C<sub>5</sub>) correlated strongly with the maturity of organic matter, enabling non-destructive ISC monitoring. Compared to typical temperatures used in ex-situ retorting (520 °C), the kerogen conversion was completed at lower temperatures of 350–420 °C in this study, validating prolonged heating as a viable low-energy ISC strategy. However, high-pressure conditions in geological formations may impede hydrocarbon expulsion efficiency, leading to the retention of viscous bitumen and thus necessitating engineered solutions for effective oil recovery. This research enriches the understanding of high-pressure pyrolysis mechanisms of immature/low-maturity unconventional resources and establishes a geochemical framework for optimizing ISC in recovering the oil from these source rocks, ultimately contributing to advancing sustainable exploitation of unconventional resources.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108327"},"PeriodicalIF":7.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044874","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}
Pub Date : 2025-09-08DOI: 10.1016/j.fuproc.2025.108328
Honglei Mi , Yifan Zhang , Faliang Luo
Monolithic NiZr0.1/SiOC catalysts with tailored architectures were fabricated via direct ink writing (DIW) 3D printing for CO2 methanation. Zr doping markedly enhanced low-temperature activity (<300 °C) by improving Ni dispersion, strengthening metal-support interactions, and suppressing particle agglomeration. Structural characterization revealed that Zr doping optimized pore accessibility and active-site exposure, while in situ studies confirmed a dual-pathway reaction mechanism involving formate and CO intermediates. The 30 % NiZr0.1/SiOC catalyst exhibited exceptional performance, achieving 95.09 % CO2 conversion at 320 °C and 91.56 % at 290 °C with 100 % CH4 selectivity. Long-term stability tests (335 h) demonstrated robust anti-coking and anti-sintering properties, attributed to Zr-induced stabilization of Ni nanoparticles. This work highlights the synergy between additive manufacturing and dopant engineering for designing high-performance catalysts for CO2 methanation.
{"title":"3D-printed NiZr0.1/SiOC monolithic catalysts with synergistic Zr doping for enhanced low-temperature CO2 methanation: dual-pathway mechanism and structural stability","authors":"Honglei Mi , Yifan Zhang , Faliang Luo","doi":"10.1016/j.fuproc.2025.108328","DOIUrl":"10.1016/j.fuproc.2025.108328","url":null,"abstract":"<div><div>Monolithic Ni<img>Zr<sub>0.1</sub>/SiOC catalysts with tailored architectures were fabricated via direct ink writing (DIW) 3D printing for CO<sub>2</sub> methanation. Zr doping markedly enhanced low-temperature activity (<300 °C) by improving Ni dispersion, strengthening metal-support interactions, and suppressing particle agglomeration. Structural characterization revealed that Zr doping optimized pore accessibility and active-site exposure, while in situ studies confirmed a dual-pathway reaction mechanism involving formate and CO intermediates. The 30 % Ni<img>Zr<sub>0.1</sub>/SiOC catalyst exhibited exceptional performance, achieving 95.09 % CO<sub>2</sub> conversion at 320 °C and 91.56 % at 290 °C with 100 % CH<sub>4</sub> selectivity. Long-term stability tests (335 h) demonstrated robust anti-coking and anti-sintering properties, attributed to Zr-induced stabilization of Ni nanoparticles. This work highlights the synergy between additive manufacturing and dopant engineering for designing high-performance catalysts for CO<sub>2</sub> methanation.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108328"},"PeriodicalIF":7.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009891","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}
Pub Date : 2025-09-08DOI: 10.1016/j.fuproc.2025.108325
Yi Lin , Zaixing Wang , Lina Tang , Shi Jiang , Yu Guo , Xiaoqin Liu
Ni-based catalysts supported on composite metal oxides (NiO-Al2O3, MgO-Al2O3, Co3O4-Al2O3) were synthesized via coprecipitation followed by Ni impregnation to investigate the influence of support composition on catalyst stability in methane steam reforming. Accelerated deactivation protocols (methane decomposition, high-temperature sintering, hydrothermal oxidation) revealed hydrothermal oxidation as the primary cause of irreversible deactivation. The 10Ni/NiAl catalyst (10 wt% Ni/10 wt% NiO-Al2O3) showed remarkable regenerability after 923 K hydrothermal treatment, fully restoring its activity. This was attributed to coexisting reduced Ni species and readily reducible NiO, facilitating rapid reactivation. Other catalysts formed thermally stable NiAl2O4, leading to permanent deactivation. Methane cracking at 973 K had negligible effect, and 10Ni/NiAl catalyst exhibited the lowest carbon deposition (17.02 %). Under extreme hydrogen purged at 1223 K, only the 10Ni/CoAl catalyst exhibited a minor activity decline. The superior stability of 10Ni/NiAl was attributed to an in situ-formed NiAl composite metal oxides during 973 K calcination, which effectively anchored Ni particles, suppressed sintering, and prevented extensive oxidation.
{"title":"Support effect in Ni-based catalysts for methane steam reforming: Role of MxOy-Al2O3 (M = Ni, Mg, Co) supports for enhanced catalyst stability","authors":"Yi Lin , Zaixing Wang , Lina Tang , Shi Jiang , Yu Guo , Xiaoqin Liu","doi":"10.1016/j.fuproc.2025.108325","DOIUrl":"10.1016/j.fuproc.2025.108325","url":null,"abstract":"<div><div>Ni-based catalysts supported on composite metal oxides (NiO-Al<sub>2</sub>O<sub>3</sub>, MgO-Al<sub>2</sub>O<sub>3</sub>, Co<sub>3</sub>O<sub>4</sub>-Al<sub>2</sub>O<sub>3</sub>) were synthesized via coprecipitation followed by Ni impregnation to investigate the influence of support composition on catalyst stability in methane steam reforming. Accelerated deactivation protocols (methane decomposition, high-temperature sintering, hydrothermal oxidation) revealed hydrothermal oxidation as the primary cause of irreversible deactivation. The 10Ni/NiAl catalyst (10 wt% Ni/10 wt% NiO-Al<sub>2</sub>O<sub>3</sub>) showed remarkable regenerability after 923 K hydrothermal treatment, fully restoring its activity. This was attributed to coexisting reduced Ni species and readily reducible NiO, facilitating rapid reactivation. Other catalysts formed thermally stable NiAl<sub>2</sub>O<sub>4</sub>, leading to permanent deactivation. Methane cracking at 973 K had negligible effect, and 10Ni/NiAl catalyst exhibited the lowest carbon deposition (17.02 %). Under extreme hydrogen purged at 1223 K, only the 10Ni/CoAl catalyst exhibited a minor activity decline. The superior stability of 10Ni/NiAl was attributed to an in situ-formed NiAl composite metal oxides during 973 K calcination, which effectively anchored Ni particles, suppressed sintering, and prevented extensive oxidation.</div></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"278 ","pages":"Article 108325"},"PeriodicalIF":7.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020277","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}
Pub Date : 2025-09-05DOI: 10.1016/j.fuproc.2025.108322
Shiyi Chen , Fangjun Wang , Jun Du , Shubo Chen , Wenguo Xiang
Chemical looping steam methane reforming (CLSMR) is an efficient and promising method to co-produce syngas and hydrogen. In this work, the La/Co doped Mg-Fe-Al-O spinel was synthesized via co-precipitation method as oxygen carrier in CLSMR. The introduction of La ions enhances the dispersion of the iron oxide on the particle surface and retards the growth of the oxygen carrier grain size, and the incorporation Co ions creates oxygen vacancies, which facilitates the lattice oxygen migration. The results reveal the optimal ratios of La: Co is 5:5 in the doping. In the reduction, the La5Co5 sample generates the syngas with a H2/CO molar ratio of ∼2, a CH4 conversion rate of 85.1 %, and a syngas yield of 3.75 mmol/goc. In the oxidation, H2 is produced with a yield of 1.25 mmol/goc and a concentration > 95 vol%. In SEM and XRD characterization analysis, the La5Co5 oxygen carrier after multiple reaction cycles exhibits minimal sintering, with stable phases and slight changes in grain size. The LaCo synergistic effect can also enhance the methane partial oxidation. The deep-reduced oxygen carrier owns sufficient oxygen vacancies as active sites for steam splitting to produce high concentration hydrogen.
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