IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-20 DOI: 10.1016/j.fuel.2025.135372

Denglong Lu , Bolun Yu , Juan He , Huiqian Dai , Zhian Wang , Haipu Li

Anaerobic fermentation for producing short-chain fatty acids (SCFAs) is recognized as a potentially practical method for waste activated sludge (WAS) disposal. However, limited dissolution and hydrolysis processes depressed the yield of SCFAs. In this study, humic acid (HA) was added to the Fe₃O₄-sodium percarbonate (SPC) system for improving SCFA production by anaerobic fermentation, with a particular focus on the underlying mechanisms. The results showed that the maximum accumulation of SCFAs (2448.24 ± 33.19 mg COD/L, acetic acid accounting for 52 %) occurred on the 8th day with the addition of 5 mg HA/g total suspended solids (TSS) to the Fe₃O₄-SPC (20 mg/g TSS Fe₃O₄ and 15 mg/g TSS SPC), which was 2.3 times that of the control group (without any chemicals) and 1.4 times that of the Fe₃O₄-SPC-H0 group (without HA). Free radical assays revealed that ·OH and·O₂^– played a predominant role in enhancing the WAS dissolution. The increasing concentrations of soluble Fe(II) and total Fe in the fermentation liquor indicated that HA could accelerate the Fe(III)/Fe(II) cycle, thereby increasing the oxidizing capacity of the Fe₃O₄-SPC-HA system, and, in turn, improving the dissolution of WAS. Furthermore, the key enzymes analysis indicated that the addition of HA notably boosted the activities of α-glucosidase and acetate kinase, and stimulated the release of NH₄⁺-N, PO₄³⁻-P, and HA from sludge floccule, which was beneficial for the recovery of these nutrients from the fermentation liquor. Therefore, this study presented an effective and sustainable strategy for the production of SCFA and resource recovery through WAS anaerobic fermentation.

{"title":"Novel insight on humic acid addition into waste activated sludge to enhance the production of short-chain fatty acids during anaerobic fermentation","authors":"Denglong Lu , Bolun Yu , Juan He , Huiqian Dai , Zhian Wang , Haipu Li","doi":"10.1016/j.fuel.2025.135372","DOIUrl":"10.1016/j.fuel.2025.135372","url":null,"abstract":"<div><div>Anaerobic fermentation for producing short-chain fatty acids (SCFAs) is recognized as a potentially practical method for waste activated sludge (WAS) disposal. However, limited dissolution and hydrolysis processes depressed the yield of SCFAs. In this study, humic acid (HA) was added to the Fe<sub>3</sub>O<sub>4</sub>-sodium percarbonate (SPC) system for improving SCFA production by anaerobic fermentation, with a particular focus on the underlying mechanisms. The results showed that the maximum accumulation of SCFAs (2448.24 ± 33.19 mg COD/L, acetic acid accounting for 52 %) occurred on the 8th day with the addition of 5 mg HA/g total suspended solids (TSS) to the Fe<sub>3</sub>O<sub>4</sub>-SPC (20 mg/g TSS Fe<sub>3</sub>O<sub>4</sub> and 15 mg/g TSS SPC), which was 2.3 times that of the control group (without any chemicals) and 1.4 times that of the Fe<sub>3</sub>O<sub>4</sub>-SPC-H0 group (without HA). Free radical assays revealed that <strong>·</strong>OH and<strong>·</strong>O<sub>2</sub><strong><sup>–</sup></strong> played a predominant role in enhancing the WAS dissolution. The increasing concentrations of soluble Fe(II) and total Fe in the fermentation liquor indicated that HA could accelerate the Fe(III)/Fe(II) cycle, thereby increasing the oxidizing capacity of the Fe<sub>3</sub>O<sub>4</sub>-SPC-HA system, and, in turn, improving the dissolution of WAS. Furthermore, the key enzymes analysis indicated that the addition of HA notably boosted the activities of α-glucosidase and acetate kinase, and stimulated the release of NH<sub>4</sub><sup>+</sup>-N, PO<sub>4</sub><sup>3−</sup>-P, and HA from sludge floccule, which was beneficial for the recovery of these nutrients from the fermentation liquor. Therefore, this study presented an effective and sustainable strategy for the production of SCFA and resource recovery through WAS anaerobic fermentation.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135372"},"PeriodicalIF":6.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850758","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}

引用次数: 0

Consistent thermodynamic properties for alicyclic components of jet fuels: Experimental data, estimation methods, and homologous series trends

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-19 DOI: 10.1016/j.fuel.2025.135222

Eugene Paulechka , Andrei Kazakov , Suphat Watanasiri , Abhijit Dutta

Alkylcycloalkanes represent a significant fraction of jet fuel components. An evaluation of their thermodynamic properties, enthalpies of formation in liquid and gas phases and enthalpies of vaporization, was conducted. A combination of available experimental data, up-to-date group-contribution methods, high-level quantum-chemical calculations, and homologous series trends was used to identify outliers and to recommend the most reliable values. The group-contribution approach was found to work well for the enthalpies of vaporization. Its performance for the enthalpies of formation in the liquid and gas phases was found to be substantially less effective, especially considering notable differences in this property among stereoisomers. Computationally affordable high-level ab initio results and homologous series trend analysis appeared more reliable. The recommended property values for 212 individual compounds and their isomeric mixtures were provided.

引用次数: 0

Fe-Co/Al-CeZr-M multi-shelled nanosphere catalysts derived from self-templated synthesis for hydrogen production by ammonia decomposition

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-19 DOI: 10.1016/j.fuel.2025.135425

Shanshan Hao , Chengchun Ding , Tao Wang , Songsheng Zheng , Zhaolin Wang

Though ammonia is seen as a promising hydrogen storage carrier, the industrial application of ammonia-catalyzed hydrogen production is restricted by the expensiveness of efficient ruthenium-based catalysts. In this study, a series of multi-shelled hollow M_xO_y nanospheres were synthesized, serving as the basis for Fe-Co/Al-Ce_0.8Zr_0.2O₂ catalysts for ammonia decomposition. A comparison was made between two preparation methods, self-template assembly (Fe-Co/Al-CeZr-M) and impregnation (Fe-Co/Al-CeZr-I), in terms of structural and catalytic performance differences. The catalytic performance and comprehensive characterization of samples indicate that the self-assembled Fe-Co/Al-CeZr-M catalyst performed superior catalytic activity, by which ammonia can be entirely decomposed under GHSV = 6,000 mL·g_cat^-1·h⁻¹ and 550°C, along with more excellent stability, and sintering resistance. This work offers valuable insights for developing efficient non-noble metal catalysts for ammonia decomposition-based hydrogen production.

{"title":"Fe-Co/Al-CeZr-M multi-shelled nanosphere catalysts derived from self-templated synthesis for hydrogen production by ammonia decomposition","authors":"Shanshan Hao , Chengchun Ding , Tao Wang , Songsheng Zheng , Zhaolin Wang","doi":"10.1016/j.fuel.2025.135425","DOIUrl":"10.1016/j.fuel.2025.135425","url":null,"abstract":"<div><div>Though ammonia is seen as a promising hydrogen storage carrier, the industrial application of ammonia-catalyzed hydrogen production is restricted by the expensiveness of efficient ruthenium-based catalysts. In this study, a series of multi-shelled hollow M<em><sub>x</sub></em>O<em><sub>y</sub></em> nanospheres were synthesized, serving as the basis for Fe-Co/Al-Ce<sub>0.8</sub>Zr<sub>0.2</sub>O<sub>2</sub> catalysts for ammonia decomposition. A comparison was made between two preparation methods, self-template assembly (Fe-Co/Al-CeZr-M) and impregnation (Fe-Co/Al-CeZr-I), in terms of structural and catalytic performance differences. The catalytic performance and comprehensive characterization of samples indicate that the self-assembled Fe-Co/Al-CeZr-M catalyst performed superior catalytic activity, by which ammonia can be entirely decomposed under GHSV = 6,000 mL·g<sub>cat</sub><sup>-1</sup>·h<sup>−1</sup> and 550°C, along with more excellent stability, and sintering resistance. This work offers valuable insights for developing efficient non-noble metal catalysts for ammonia decomposition-based hydrogen production.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135425"},"PeriodicalIF":6.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850756","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}

引用次数: 0

Enhanced selective oxidation of 5-Hydroxymethylfurfural with a recyclable V34@Fe3O4/C catalyst Enriched with Mixed-valence polyoxovanadate active centers

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-19 DOI: 10.1016/j.fuel.2025.135439

Chunhui Zhang, Mengqi Wang, Changhao Zhao, Junpeng Wang, Yundong Cao, Linlin Fan, Hong Liu, Guang-Gang Gao

Exploring and discovering high-performance catalysts that efficiently catalyze the conversion of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) is of great significance for the future development of pharmaceuticals and polymers. Unlike the vanadium-substituted polyoxometalates previously employed for HMF catalytic conversion, this study examined a series of polyvanadates with well-defined structures, among which the 34-nuclear polyoxovanadate (V₃₄) demonstrated exceptional catalytic performance. In addition to the conventional notion that oxidation capability aids catalytic conversion, the terminal oxygen of V₃₄ exhibits superior hydrogen adsorption properties, thereby further enhancing the catalytic conversion of HMF. Under optimized conditions, the conversion rate of HMF and the yield of DFF can reach 98.7% and 97.2%, respectively. Additionally, via a hydrothermal method, V₃₄ can be easily loaded onto the magnetically nanospindle Fe₃O₄/C support generated from the carbonization of MIL-88(Fe), forming the V₃₄@Fe₃O₄/C composite catalyst. This catalyst maintains its efficiency in the directed conversion of HMF even under relatively moderate conditions, achieving conversion rates and DFF yields that are nearly 100%. Following 10 cycles of magnetic separation, the catalytic performance remains virtually unaltered, showcasing exceptional catalytic stability and recyclability. Further investigation into the catalytic mechanism of the V₃₄@Fe₃O₄/C catalyst uncovered a synergistic effect between Fe₃O₄/C and V₃₄. This interaction facilitates the transfer of electrons and protons in the proton-coupled electron transfer process, thereby enhancing catalytic efficiency. The synthesis of the V₃₄@Fe₃O₄/C polyoxometalate catalyst not only expands the range of HMF catalysts but also presents a novel technological strategy for the design of efficient and recyclable green biomass catalysts.

{"title":"Enhanced selective oxidation of 5-Hydroxymethylfurfural with a recyclable V34@Fe3O4/C catalyst Enriched with Mixed-valence polyoxovanadate active centers","authors":"Chunhui Zhang, Mengqi Wang, Changhao Zhao, Junpeng Wang, Yundong Cao, Linlin Fan, Hong Liu, Guang-Gang Gao","doi":"10.1016/j.fuel.2025.135439","DOIUrl":"10.1016/j.fuel.2025.135439","url":null,"abstract":"<div><div>Exploring and discovering high-performance catalysts that efficiently catalyze the conversion of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) is of great significance for the future development of pharmaceuticals and polymers. Unlike the vanadium-substituted polyoxometalates previously employed for HMF catalytic conversion, this study examined a series of polyvanadates with well-defined structures, among which the 34-nuclear polyoxovanadate (V<sub>34</sub>) demonstrated exceptional catalytic performance. In addition to the conventional notion that oxidation capability aids catalytic conversion, the terminal oxygen of V<sub>34</sub> exhibits superior hydrogen adsorption properties, thereby further enhancing the catalytic conversion of HMF. Under optimized conditions, the conversion rate of HMF and the yield of DFF can reach 98.7% and 97.2%, respectively. Additionally, via a hydrothermal method, V<sub>34</sub> can be easily loaded onto the magnetically nanospindle Fe<sub>3</sub>O<sub>4</sub>/C support generated from the carbonization of MIL-88(Fe), forming the V<sub>34</sub>@Fe<sub>3</sub>O<sub>4</sub>/C composite catalyst. This catalyst maintains its efficiency in the directed conversion of HMF even under relatively moderate conditions, achieving conversion rates and DFF yields that are nearly 100%. Following 10 cycles of magnetic separation, the catalytic performance remains virtually unaltered, showcasing exceptional catalytic stability and recyclability. Further investigation into the catalytic mechanism of the V<sub>34</sub>@Fe<sub>3</sub>O<sub>4</sub>/C catalyst uncovered a synergistic effect between Fe<sub>3</sub>O<sub>4</sub>/C and V<sub>34</sub>. This interaction facilitates the transfer of electrons and protons in the proton-coupled electron transfer process, thereby enhancing catalytic efficiency. The synthesis of the V<sub>34</sub>@Fe<sub>3</sub>O<sub>4</sub>/C polyoxometalate catalyst not only expands the range of HMF catalysts but also presents a novel technological strategy for the design of efficient and recyclable green biomass catalysts.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135439"},"PeriodicalIF":6.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848706","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}

引用次数: 0

Enhanced acidic hydrogen evolution stability and activity in CoP through S doping for proton exchange membrane electrolyzers

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-19 DOI: 10.1016/j.fuel.2025.135436

Shiqing Zhang , Shaokai Ma , Zihao Wang , Zihang Cao , Fang Liu , Ying Li , Xuewen Xu , Yuanhui Ma , Yanming Xue , Chengchun Tang , Jun Zhang

The development of cost-effective, highly efficient, and stable electrocatalysts for the acidic hydrogen evolution reaction (HER) is essential for advancing clean and renewable hydrogen energy technologies. This is particularly critical for proton exchange membrane (PEM) electrolyzers powered by renewable energy sources. Among various candidates, cobalt-based phosphide (CoP) has emerged as a promising catalyst for the HER in acidic media, owing to the synergistic interaction between Co and P, as well as its inherent stability. Despite significant efforts to enhance its catalytic activity, the critical issue of stability has often been overlooked. Herein, sulfur (S), which has a higher electronegativity than P, is selectively incorporated into CoP nanowire arrays through a simple vulcanization method. This strategy aims to enhance stability without altering catalytic activity. The optimized S-CoP/CC electrocatalyst shows an overpotential of 96 mV at 10 mA cm⁻² in acid electrolyte, showing a slight improvement over the initial CoP/CC (114 mV). Remarkably, it shows exceptional durability, maintaining excellent stability over 150 h of testing in acid solution. The incorporation of sulfur serves a dual role: it enhances electronic conductivity and increases the electrochemical surface area, thereby improving catalytic activity, while simultaneously strengthening the CoP bond energy, leading to outstanding acid stability. Furthermore, when employed as the cathode in a PEM electrolyzer, S-CoP/CC achieves a current density of 500 mA cm⁻² at 1.70 V, demonstrating excellent stability over 140 h at 60 °C. Our findings present a new approach for enhancing both the stability and activity of acidic HER by incorporating higher-electronegativity anions into the CoP lattice. This strategy is applicable not only to Co-based phosphides but also to other non-precious metal-based transition metal compounds, paving the way for the development of high-performance PEM electrolyzers.

{"title":"Enhanced acidic hydrogen evolution stability and activity in CoP through S doping for proton exchange membrane electrolyzers","authors":"Shiqing Zhang , Shaokai Ma , Zihao Wang , Zihang Cao , Fang Liu , Ying Li , Xuewen Xu , Yuanhui Ma , Yanming Xue , Chengchun Tang , Jun Zhang","doi":"10.1016/j.fuel.2025.135436","DOIUrl":"10.1016/j.fuel.2025.135436","url":null,"abstract":"<div><div>The development of cost-effective, highly efficient, and stable electrocatalysts for the acidic hydrogen evolution reaction (HER) is essential for advancing clean and renewable hydrogen energy technologies. This is particularly critical for proton exchange membrane (PEM) electrolyzers powered by renewable energy sources. Among various candidates, cobalt-based phosphide (CoP) has emerged as a promising catalyst for the HER in acidic media, owing to the synergistic interaction between Co and P, as well as its inherent stability. Despite significant efforts to enhance its catalytic activity, the critical issue of stability has often been overlooked. Herein, sulfur (S), which has a higher electronegativity than P, is selectively incorporated into CoP nanowire arrays through a simple vulcanization method. This strategy aims to enhance stability without altering catalytic activity. The optimized S-CoP/CC electrocatalyst shows an overpotential of 96 mV at 10 mA cm<sup>−2</sup> in acid electrolyte, showing a slight improvement over the initial CoP/CC (114 mV). Remarkably, it shows exceptional durability, maintaining excellent stability over 150 h of testing in acid solution. The incorporation of sulfur serves a dual role: it enhances electronic conductivity and increases the electrochemical surface area, thereby improving catalytic activity, while simultaneously strengthening the CoP bond energy, leading to outstanding acid stability. Furthermore, when employed as the cathode in a PEM electrolyzer, S-CoP/CC achieves a current density of 500 mA cm<sup>−2</sup> at 1.70 V, demonstrating excellent stability over 140 h at 60 °C. Our findings present a new approach for enhancing both the stability and activity of acidic HER by incorporating higher-electronegativity anions into the CoP lattice. This strategy is applicable not only to Co-based phosphides but also to other non-precious metal-based transition metal compounds, paving the way for the development of high-performance PEM electrolyzers.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135436"},"PeriodicalIF":6.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850765","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}

引用次数: 0

Transportation fuel production by catalytic co-pyrolysis of pinewood biomass and used engine oil over HZSM-5@MCM-41 catalysts

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-18 DOI: 10.1016/j.fuel.2025.135406

Mokhtar A. Babatabar , Ahmad Tavasoli , Reyhaneh Kaveh

In this study, the performance of HZSM-5@MCM-41 core–shell catalysts was evaluated for the co-pyrolysis of pinewood (as a biomass source) and used engine oil (as hydrogen-rich waste) to enhance bio-oil quality. The results indicated that the use of catalysts increased biogas yield while reducing bio-oil yield, attributed to the removal of oxygenated functional groups. The investigation demonstrated that the catalytic co-pyrolysis process’s effectiveness in improving bio-oil quality depended significantly on the ratio of micro- and mesoporous structures. Among the catalysts examined, HZ/MC-1.5 (CTAB/HZSM-5 = 1.5) exhibited superior performance in terms of crystallinity, acidity, and surface properties. The incorporation of MCM-41 shells on the HZSM-5 core reduced coke formation from 4.2 % in the HZSM-5 catalyst to 1.5 % in the HZ/MC-1.5 catalyst, thereby enhancing catalytic activity during the co-pyrolysis process. The HZ/MC-1.5 core–shell catalyst achieved the highest degree of deoxygenation (78.1 %) and produced biofuels with improved quality, characterized by the highest H/C_eff ratio (1.65), the highest HHV (42.56 MJ/kg), and the lowest O/C ratio (0.05). In the presence of the HZ/MC-1.5 catalyst, the highest yields of aromatic (30.12 %) and naphthenic (21.13 %) compounds were obtained. Furthermore, the catalyst improved the yield of gasoline-, kerosene-, and diesel-range hydrocarbons compared to HZSM-5, with minimal impact on the yield of heavy components (>C20). The biofuel produced via catalytic co-pyrolysis in this study exhibited significantly improved properties compared to commercial heavy fuel and was comparable to commercial diesel and gasoline fuels.

{"title":"Transportation fuel production by catalytic co-pyrolysis of pinewood biomass and used engine oil over HZSM-5@MCM-41 catalysts","authors":"Mokhtar A. Babatabar , Ahmad Tavasoli , Reyhaneh Kaveh","doi":"10.1016/j.fuel.2025.135406","DOIUrl":"10.1016/j.fuel.2025.135406","url":null,"abstract":"<div><div>In this study, the performance of HZSM-5@MCM-41 core–shell catalysts was evaluated for the co-pyrolysis of pinewood (as a biomass source) and used engine oil (as hydrogen-rich waste) to enhance bio-oil quality. The results indicated that the use of catalysts increased biogas yield while reducing bio-oil yield, attributed to the removal of oxygenated functional groups. The investigation demonstrated that the catalytic co-pyrolysis process’s effectiveness in improving bio-oil quality depended significantly on the ratio of micro- and mesoporous structures. Among the catalysts examined, HZ/MC-1.5 (CTAB/HZSM-5 = 1.5) exhibited superior performance in terms of crystallinity, acidity, and surface properties. The incorporation of MCM-41 shells on the HZSM-5 core reduced coke formation from 4.2 % in the HZSM-5 catalyst to 1.5 % in the HZ/MC-1.5 catalyst, thereby enhancing catalytic activity during the co-pyrolysis process. The HZ/MC-1.5 core–shell catalyst achieved the highest degree of deoxygenation (78.1 %) and produced biofuels with improved quality, characterized by the highest H/C<sub>eff</sub> ratio (1.65), the highest HHV (42.56 MJ/kg), and the lowest O/C ratio (0.05). In the presence of the HZ/MC-1.5 catalyst, the highest yields of aromatic (30.12 %) and naphthenic (21.13 %) compounds were obtained. Furthermore, the catalyst improved the yield of gasoline-, kerosene-, and diesel-range hydrocarbons compared to HZSM-5, with minimal impact on the yield of heavy components (>C20). The biofuel produced via catalytic co-pyrolysis in this study exhibited significantly improved properties compared to commercial heavy fuel and was comparable to commercial diesel and gasoline fuels.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135406"},"PeriodicalIF":6.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848691","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}

引用次数: 0

Breaking the temperature barrier: Unveiling the potential of ceria nanorods for low temperature thermochemical water splitting

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-18 DOI: 10.1016/j.fuel.2025.135251

Dhanaji R.Naikwadi , Vaishnavi Ganesh , Hesham Sharaf , Michele Offidani , Stefania Albonetti , Nikolaos Dimitratos , Atul Bansode

Thermochemical Water-Splitting (TCWS) is a promising approach for generating clean hydrogen (H₂) by employing the waste heat originating from different sources. High-temperature requirements and temperature swing approach hinder the widespread adoption of TCWS for clean hydrogen production. This study explores ceria nanorods (CeNRs) as a potential solution for overcoming these limitations. Herein, we report, the TCWS in a fixed bed reactor using CeNRs at low and constant temperature of 400 °C. We systematically explore the influence of synthesis parameters on the resulting CeNRs, including the selection of ceria precursor, effect of calcination, and their impact in TCWS. It was found that CeNRs prepared using cerium chloride as the precursor exhibited enhanced TCWS activity, resulting significantly higher total H₂ yield 4.74 mL/g, at a constant temperature of 400 °C in three redox cycles. Moreover, X-ray Photoelectron Spectroscopy (XPS) analysis confirms the presence of both Ce³⁺ and Ce⁴⁺ states within the structure, with Ce³⁺ constituting approximately 30 % and Ce⁴⁺ accounting for approximately 70 % of the total cerium content. Additionally, Raman spectroscopy corroborates the presence of a higher concentration of oxygen vacancy which are beneficial for increasing the hydrogen production. We demonstrate that ceria in its nanorod structure having exposed higher proportions of (110) and (100) planes and higher concentration of oxygen vacancies is beneficial for lowering TCWS temperature as well as increasing the hydrogen yield.

{"title":"Breaking the temperature barrier: Unveiling the potential of ceria nanorods for low temperature thermochemical water splitting","authors":"Dhanaji R.Naikwadi , Vaishnavi Ganesh , Hesham Sharaf , Michele Offidani , Stefania Albonetti , Nikolaos Dimitratos , Atul Bansode","doi":"10.1016/j.fuel.2025.135251","DOIUrl":"10.1016/j.fuel.2025.135251","url":null,"abstract":"<div><div>Thermochemical Water-Splitting (TCWS) is a promising approach for generating clean hydrogen (H<sub>2</sub>) by employing the waste heat originating from different sources. High-temperature requirements and temperature swing approach hinder the widespread adoption of TCWS for clean hydrogen production. This study explores ceria nanorods (CeNRs) as a potential solution for overcoming these limitations. Herein, we report, the TCWS in a fixed bed reactor using CeNRs at low and constant temperature of 400 °C. We systematically explore the influence of synthesis parameters on the resulting CeNRs, including the selection of ceria precursor, effect of calcination, and their impact in TCWS. It was found that CeNRs prepared using cerium chloride as the precursor exhibited enhanced TCWS activity, resulting significantly higher total H<sub>2</sub> yield 4.74 mL/g, at a constant temperature of 400 °C in three redox cycles. Moreover, X-ray Photoelectron Spectroscopy (XPS) analysis confirms the presence of both Ce<sup>3+</sup> and Ce<sup>4+</sup> states within the structure, with Ce<sup>3+</sup> constituting approximately 30 % and Ce<sup>4+</sup> accounting for approximately 70 % of the total cerium content. Additionally, Raman spectroscopy corroborates the presence of a higher concentration of oxygen vacancy which are beneficial for increasing the hydrogen production. We demonstrate that ceria in its nanorod structure having exposed higher proportions of (110) and (100) planes and higher concentration of oxygen vacancies is beneficial for lowering TCWS temperature as well as increasing the hydrogen yield.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135251"},"PeriodicalIF":6.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848708","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}

引用次数: 0

The stable combustion and blowout characteristics investigation of the water injection pre-cooling on the afterburners

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-18 DOI: 10.1016/j.fuel.2025.135422

Pengyu He, Chen Yue, Yuxin Fan

Mass Injection and Pre-compressor Cooling (MIPCC) technology is a promising approach to improve thrust performance, through extending the turbine mode upper operating limit in Turbine-Based Combined Cycle (TBCC) engines. However, The introduction of cooling media results in a lowered flame temperature inside the afterburner and a reduced oxygen content at its inlet, which might result in combustion instability and blowout. Employing both numerical simulations and experimental testing methods, the influences of water injection on the stable combustion characteristics and blowout behavior of the afterburner in the turbine mode of TBCC engine were investigated in this study. The numerical results indicated that the introduction of water injection reduced velocity and turbulence fluctuations within the recirculation zone behind the V-shaped blunt body flame stabilizer. The experimental results indicate that the combustion stability of the flame remains almost unaffected, with the maximal fluctuation rate increasing by about 2 % within the water injection range of up to 5 %. Moreover, the combustion stability is significantly enhanced and the flame combustion area is increased by 16.6 % at the water injection ratio of approximately 2 %, compared with the case without water injection under the incoming flow temperature condition of 900 K. Flame blowout behavior revealed the existence of an optimal water injection ratio (less than 2 %) that enhanced the flame’s resistance to disturbances near-blowout stage, and thereby improved the afterburner’s blowout performance. This study provides crucial theoretical support for the application of MIPCC technology in TBCC engines, offering significant implications for improving the combustion reliability of afterburners.

{"title":"The stable combustion and blowout characteristics investigation of the water injection pre-cooling on the afterburners","authors":"Pengyu He, Chen Yue, Yuxin Fan","doi":"10.1016/j.fuel.2025.135422","DOIUrl":"10.1016/j.fuel.2025.135422","url":null,"abstract":"<div><div>Mass Injection and Pre-compressor Cooling (MIPCC) technology is a promising approach to improve thrust performance, through extending the turbine mode upper operating limit in Turbine-Based Combined Cycle (TBCC) engines. However, The introduction of cooling media results in a lowered flame temperature inside the afterburner and a reduced oxygen content at its inlet, which might result in combustion instability and blowout. Employing both numerical simulations and experimental testing methods, the influences of water injection on the stable combustion characteristics and blowout behavior of the afterburner in the turbine mode of TBCC engine were investigated in this study. The numerical results indicated that the introduction of water injection reduced velocity and turbulence fluctuations within the recirculation zone behind the V-shaped blunt body flame stabilizer. The experimental results indicate that the combustion stability of the flame remains almost unaffected, with the maximal fluctuation rate increasing by about 2 % within the water injection range of up to 5 %. Moreover, the combustion stability is significantly enhanced and the flame combustion area is increased by 16.6 % at the water injection ratio of approximately 2 %, compared with the case without water injection under the incoming flow temperature condition of 900 K. Flame blowout behavior revealed the existence of an optimal water injection ratio (less than 2 %) that enhanced the flame’s resistance to disturbances near-blowout stage, and thereby improved the afterburner’s blowout performance. This study provides crucial theoretical support for the application of MIPCC technology in TBCC engines, offering significant implications for improving the combustion reliability of afterburners.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135422"},"PeriodicalIF":6.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848092","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}

引用次数: 0

Dual-defect-driven triple built-in electric fields to facilitate charge rapid separation of ZnIn2S4-Vs/TMC-Vo core-shell S-scheme heterojunction for boosting machine vision-assisted photothermal H2 evolution 双缺陷驱动的三重内置电场促进 ZnIn2S4-Vs/TMC-Vo 核壳 S 型异质结的电荷快速分离，从而提高机器视觉辅助光热 H2 演化的效率

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-18 DOI: 10.1016/j.fuel.2025.135423

Yueyue Xu , Yanfei Lu , Lianqing Chen , Jinsi Lei , Shiwei Jin , Dingguo Tang , Benjun Xi , Hua Zhou , Yu Cai

Built-in electric fields play a crucial role in enhancing the charge separation efficiency. The ZIS-R/TMC-Vo core–shell S-scheme heterostructures with different vacancy concentrations were prepared by NaBH₄ reduction and TAA content adjustment. The presence of S, O dual-defect was confirmed by HRTEM, EPR, and XPS characterization. The unique structure enables catalysts to fully utilize the visible light and convert it into thermal energy, with a high center temperature of 116.9 °C in 90 s. Dual defects can be used as electron traps, efficiently promoting charge separation. The high vacancy concentration resulted in a highly uneven distribution of electrons, which contributed to the formation of inner electric fields within the semiconductors, expanding the Fermi energy level (E_f) and increasing the interfacial electric field strength, thereby constructing the triple built-in electric fields and greatly enhancing the driving force of charge separation. The catalysts exhibited excellent water purification and hydrogen evolution performance under visible light, and the photothermal catalytic degradation was assisted by machine vision to improve the accuracy of the degradation process. 20ZT-R degraded RhB up to 99.7 % in 40.4 min, and the removal of Cr(Ⅵ) by 20ZT-R reached 99.6 % in 20.3 min. Meanwhile, hydrogen evolution up to 44,500 μmol g-1 in 6 h, the PHE rate of 20ZT-R was 7420 μmol g^-1h⁻¹ of 20ZT-R, which was 157.9 and 24.4 times more than TMC and ZIS-P, respectively. It is shown that higher vacancy concentration can significantly improve the rapid charge separation. This work provides new insights into the modulation of vacancy concentration to construct and enhance built-in electric fields in S-scheme heterojunction for water purification and H₂ evolution.

{"title":"Dual-defect-driven triple built-in electric fields to facilitate charge rapid separation of ZnIn2S4-Vs/TMC-Vo core-shell S-scheme heterojunction for boosting machine vision-assisted photothermal H2 evolution","authors":"Yueyue Xu , Yanfei Lu , Lianqing Chen , Jinsi Lei , Shiwei Jin , Dingguo Tang , Benjun Xi , Hua Zhou , Yu Cai","doi":"10.1016/j.fuel.2025.135423","DOIUrl":"10.1016/j.fuel.2025.135423","url":null,"abstract":"<div><div>Built-in electric fields play a crucial role in enhancing the charge separation efficiency. The ZIS-R/TMC-Vo core–shell S-scheme heterostructures with different vacancy concentrations were prepared by NaBH<sub>4</sub> reduction and TAA content adjustment. The presence of S, O dual-defect was confirmed by HRTEM, EPR, and XPS characterization. The unique structure enables catalysts to fully utilize the visible light and convert it into thermal energy, with a high center temperature of 116.9 °C in 90 s. Dual defects can be used as electron traps, efficiently promoting charge separation. The high vacancy concentration resulted in a highly uneven distribution of electrons, which contributed to the formation of inner electric fields within the semiconductors, expanding the Fermi energy level (E<sub>f</sub>) and increasing the interfacial electric field strength, thereby constructing the triple built-in electric fields and greatly enhancing the driving force of charge separation. The catalysts exhibited excellent water purification and hydrogen evolution performance under visible light, and the photothermal catalytic degradation was assisted by machine vision to improve the accuracy of the degradation process. 20ZT-R degraded RhB up to 99.7 % in 40.4 min, and the removal of Cr(Ⅵ) by 20ZT-R reached 99.6 % in 20.3 min. Meanwhile, hydrogen evolution up to 44,500 μmol g-1 in 6 h, the PHE rate of 20ZT-R was 7420 μmol g<sup>-1</sup>h<sup>−1</sup> of 20ZT-R, which was 157.9 and 24.4 times more than TMC and ZIS-P, respectively. It is shown that higher vacancy concentration can significantly improve the rapid charge separation. This work provides new insights into the modulation of vacancy concentration to construct and enhance built-in electric fields in S-scheme heterojunction for water purification and H<sub>2</sub> evolution.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135423"},"PeriodicalIF":6.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848091","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}

引用次数: 0

Transformation of waste cooking oil into biodiesel in a microwave reactor using nickel-loaded graphitic biochar catalyst 使用镍负载石墨生物炭催化剂在微波反应器中将废食用油转化为生物柴油

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel

Pub Date : 2025-04-18 DOI: 10.1016/j.fuel.2025.135369

Rahul Mishra , Chi-Min Shu , Anjani R.K. Gollakota

This study focuses on the catalytic efficiency of synthesized metal-loaded graphitic biochar catalyst for one-step production of biodiesel from waste cooking oil (WCO). Biomass waste was a precursor for synthesizing nickel-loaded graphitic biochar (Ni-Ca-GBC). The artificial neural networks (ANN) modeling and response surface methodology (RSM) were applied to assess the reaction parameters and biodiesel conversion. The Box-Behnken Design (BBD) method was utilized to optimize reaction parameters for the transesterification reaction. The maximum fatty acid methyl esters (FAMEs) conversion was ca. 94.6 % at a catalyst loading of 6 wt.%, a reaction temperature of 80 °C, a methanol-oil molar ratio of 12:1, and a reaction time of 35 min. The maximum product yield was roughly 89.3 % using the same reaction parameters. Using optimized parameters of RSM, the maximum conversion (approximately 97.3 %) was achieved. Furthermore, Ni-Ca-GBC was compared with Ni-BC, Ni-Al-Fe-BC, and pristine biochar and showed maximum biodiesel conversion. The catalyst reusability was studied six times, and it was observed that the biodiesel conversion started to reduce after three times catalyst reuse. A comparative analysis of microwave (ca. 94.3 % conversion at 80 °C) and conventional heating (ca. 80.3 % at 80 °C) found that microwave heating was more efficient. ANN predictions appeared to be slightly more aligned with experimental results than RSM. Moreover, all the physicochemical properties of the biodiesel produced in this study were compatible with European norms (EN–14214) and American Society for Testing and Materials (ASTM D–6751) standards. This paper demonstrated the perspective of catalysts obtained from biomass to generate green fuels, which can help promote sustainable energy production.

{"title":"Transformation of waste cooking oil into biodiesel in a microwave reactor using nickel-loaded graphitic biochar catalyst","authors":"Rahul Mishra , Chi-Min Shu , Anjani R.K. Gollakota","doi":"10.1016/j.fuel.2025.135369","DOIUrl":"10.1016/j.fuel.2025.135369","url":null,"abstract":"<div><div>This study focuses on the catalytic efficiency of synthesized metal-loaded graphitic biochar catalyst for one-step production of biodiesel from waste cooking oil (WCO). Biomass waste was a precursor for synthesizing nickel-loaded graphitic biochar (Ni-Ca-GBC). The artificial neural networks (ANN) modeling and response surface methodology (RSM) were applied to assess the reaction parameters and biodiesel conversion. The Box-Behnken Design (BBD) method was utilized to optimize reaction parameters for thetransesterification reaction. The maximum fatty acid methyl esters (FAMEs) conversion was ca. 94.6 % at a catalyst loading of 6 wt.%, a reaction temperature of 80 °C, a methanol-oil molar ratio of 12:1, and a reaction time of 35 min. The maximum product yield was roughly 89.3 % using the same reaction parameters. Using optimized parameters of RSM, the maximum conversion (approximately 97.3 %) was achieved. Furthermore, Ni-Ca-GBC was compared with Ni-BC, Ni-Al-Fe-BC, and pristine biochar and showed maximum biodiesel conversion. The catalyst reusability was studied six times, and it wasobserved that the biodiesel conversion started to reduce after three times catalyst reuse. A comparative analysis of microwave (ca. 94.3 % conversion at 80 °C) and conventional heating (ca. 80.3 % at 80 °C) found that microwave heating was more efficient. ANN predictions appeared to be slightly more aligned with experimental results than RSM. Moreover, all the physicochemical properties of the biodiesel produced in this study were compatible with European norms (EN–14214) and American Society for Testing and Materials (ASTM D–6751) standards. This paper demonstrated the perspective of catalysts obtained from biomass to generate green fuels, which can helppromote sustainable energy production.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"397 ","pages":"Article 135369"},"PeriodicalIF":6.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848094","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}

引用次数: 0

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