Pub Date : 2025-12-09DOI: 10.1016/j.joei.2025.102410
Zeru Gong , Chen Zhang , Anyao Jiao , Fang Wu , Jiaxun Liu , Junfu Lyu
Partial gasification is an available method for the efficient and clean utilization of pulverized coal. In this study, the homogeneous reduction mechanisms of NO during coal partial gasification were elucidated by the combination of experimental and molecular dynamics approaches. The effects of temperature and reburning gas composition on NO reduction efficiency were investigated in a one-dimensional furnace. Results indicate that the NO reduction efficiency increases with rising temperature, while H2 exerts a significant enhancing effect on this process. Reactive force field molecular dynamics (ReaxFF MD) was employed to emphatically evaluate the capacity of homogeneous reducing NO by CO and H2 under fuel-rich conditions, exploring the reaction mechanisms at the molecular level to further verify the experimental results. Thermodynamic analyses reveal that H2 exhibits a stronger reducing capability of NO with an optimal conversion temperature around 3200 K. CO reacts with NO at a lower rate and has an inhibitory effect in the presence of H2. The presence of O2 promotes the NO reduction reactions by generating radicals and increasing the N2 yield. These results contribute to the understanding of the NO homogeneous reduction mechanisms under coal partial gasification conditions, which provides theoretical support for clean coal combustion and low nitrogen emissions.
{"title":"Enhanced homogeneous reduction mechanisms of NO during the pulverized coal partial gasification process: Insight from experiments and ReaxFF MD","authors":"Zeru Gong , Chen Zhang , Anyao Jiao , Fang Wu , Jiaxun Liu , Junfu Lyu","doi":"10.1016/j.joei.2025.102410","DOIUrl":"10.1016/j.joei.2025.102410","url":null,"abstract":"<div><div>Partial gasification is an available method for the efficient and clean utilization of pulverized coal. In this study, the homogeneous reduction mechanisms of NO during coal partial gasification were elucidated by the combination of experimental and molecular dynamics approaches. The effects of temperature and reburning gas composition on NO reduction efficiency were investigated in a one-dimensional furnace. Results indicate that the NO reduction efficiency increases with rising temperature, while H<sub>2</sub> exerts a significant enhancing effect on this process. Reactive force field molecular dynamics (ReaxFF MD) was employed to emphatically evaluate the capacity of homogeneous reducing NO by CO and H<sub>2</sub> under fuel-rich conditions, exploring the reaction mechanisms at the molecular level to further verify the experimental results. Thermodynamic analyses reveal that H<sub>2</sub> exhibits a stronger reducing capability of NO with an optimal conversion temperature around 3200 K. CO reacts with NO at a lower rate and has an inhibitory effect in the presence of H<sub>2</sub>. The presence of O<sub>2</sub> promotes the NO reduction reactions by generating radicals and increasing the N<sub>2</sub> yield. These results contribute to the understanding of the NO homogeneous reduction mechanisms under coal partial gasification conditions, which provides theoretical support for clean coal combustion and low nitrogen emissions.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102410"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733429","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 : 2025-12-06DOI: 10.1016/j.joei.2025.102404
Shuman Guo , Jiaqi Wang , Dong Liu , Chen Hong , Lijun Wang , Haichao Liu , Yuguo Gao , Nannan Zhang , Zhenzhong Yang , Chunjian Zhou
Propane is regarded as a potential alternative fuel for internal combustion engines (ICEs) due to its high calorific value and cleanliness. However, its application is constrained by issues such as low laminar burning velocity (LBV) and combustion instability. Ozone, as a combustion enhancer, accelerates flame kernel formation, enhances flame propagation and stability, and thus holds promise for addressing the disadvantages of propane as an ICE fuel. Existing research on ozone-assisted propane combustion has primarily focused on atmospheric pressure conditions, while studies on combustion characteristics and reaction mechanisms under medium-to-low pressure conditions remain scarce. This gap prompts the initiation of this work. This study evaluates the effects of various ambient pressure (0.1–0.2 MPa) and ozone concentrations (0 ppm, 2500 ppm, 5000 ppm) on the laminar combustion characteristics of propane under ambient temperature. Research findings reveal that under varying pressure, the heat released by ozonolysis within the pre-ignition region consistently elevates the adiabatic flame temperature (AFT) and increases the concentrations of radicals H, OH, and O. This contributes to accelerating the LBV. Specifically, at an ambient pressure of 0.1 MPa and φ = 1, the LBV of the mixture increased by approximately 17.9 % when the ozone concentration rose from 0 to 5000 ppm. Notably, the elevated oxygen concentrations influenced the reaction pathways, resulting in a ‘bulge region’ for the O3 = O2 + O reaction within the pre-ignition region. Furthermore, the O2+ H = OH + O reaction exerts the greatest influence on the LBV. At atmospheric pressure, the sensitivity coefficient for this reaction is 0.407, gradually decreasing with increasing ozone concentration.
{"title":"Study on the mechanism of ozone's influence on the laminar combustion characteristics of propane under different ambient pressure","authors":"Shuman Guo , Jiaqi Wang , Dong Liu , Chen Hong , Lijun Wang , Haichao Liu , Yuguo Gao , Nannan Zhang , Zhenzhong Yang , Chunjian Zhou","doi":"10.1016/j.joei.2025.102404","DOIUrl":"10.1016/j.joei.2025.102404","url":null,"abstract":"<div><div>Propane is regarded as a potential alternative fuel for internal combustion engines (ICEs) due to its high calorific value and cleanliness. However, its application is constrained by issues such as low laminar burning velocity (LBV) and combustion instability. Ozone, as a combustion enhancer, accelerates flame kernel formation, enhances flame propagation and stability, and thus holds promise for addressing the disadvantages of propane as an ICE fuel. Existing research on ozone-assisted propane combustion has primarily focused on atmospheric pressure conditions, while studies on combustion characteristics and reaction mechanisms under medium-to-low pressure conditions remain scarce. This gap prompts the initiation of this work. This study evaluates the effects of various ambient pressure (0.1–0.2 MPa) and ozone concentrations (0 ppm, 2500 ppm, 5000 ppm) on the laminar combustion characteristics of propane under ambient temperature. Research findings reveal that under varying pressure, the heat released by ozonolysis within the pre-ignition region consistently elevates the adiabatic flame temperature (AFT) and increases the concentrations of radicals H, OH, and O. This contributes to accelerating the LBV. Specifically, at an ambient pressure of 0.1 MPa and φ = 1, the LBV of the mixture increased by approximately 17.9 % when the ozone concentration rose from 0 to 5000 ppm. Notably, the elevated oxygen concentrations influenced the reaction pathways, resulting in a ‘bulge region’ for the O<sub>3</sub> = O<sub>2</sub> + O reaction within the pre-ignition region. Furthermore, the O<sub>2</sub>+ H = OH + O reaction exerts the greatest influence on the LBV. At atmospheric pressure, the sensitivity coefficient for this reaction is 0.407, gradually decreasing with increasing ozone concentration.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102404"},"PeriodicalIF":6.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786495","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 : 2025-12-05DOI: 10.1016/j.joei.2025.102403
Zhengming Yi , Zihang Zhou , Zhuo Deng , Xiaolin Chen
Refuse-derived fuel (RDF), a promising alternative fuel for energy recovery and waste treatment, generates nitrogen oxides (NOx) during precalciner combustion. This study systematically investigates the interactive effects of three key operational parameters—combustion temperature, O2 concentration, and CaO mass ratio—on NOx generation characteristics during RDF combustion using Response Surface Methodology (RSM). A Box-Behnken experimental design was employed to develop a quadratic regression model for NOx emissions, followed by analysis of variance (ANOVA) and model validation. The results indicate that O2 concentration has the most significant impact on the peak NOx release (Peak-NOx), with a model F-statistic of 15.76 and a probability value P < 0.01. An increase in O2 concentration weakens the influence of combustion temperature on Peak-NOx, while an increase in the CaO mass ratio alters the trend of temperature's effect on Peak-NOx. On the other hand, combustion temperature exhibits the greatest influence on total NOx generation (Total-NOx), with parameter interactions being significant only within the 800 °C–900 °C range. The developed models show high goodness-of-fit, with R2 values of 0.9216 for Peak-NOx and 0.9835 for Total-NOx. Furthermore, multi-objective optimization identified the optimal combustion parameters (884 °C, 13 % O2, 6 % CaO), under which Peak-NOx and Total-NOx were reduced to 236 ppm and 0.87 mg, respectively. These findings provide a theoretical foundation and technical guidance for controlling NOx emissions during RDF combustion in precalciners.
{"title":"Study of NOx formation characteristics and influencing parameters in refuse derived fuel combustion using response surface methodology","authors":"Zhengming Yi , Zihang Zhou , Zhuo Deng , Xiaolin Chen","doi":"10.1016/j.joei.2025.102403","DOIUrl":"10.1016/j.joei.2025.102403","url":null,"abstract":"<div><div>Refuse-derived fuel (RDF), a promising alternative fuel for energy recovery and waste treatment, generates nitrogen oxides (NO<sub><em>x</em></sub>) during precalciner combustion. This study systematically investigates the interactive effects of three key operational parameters—combustion temperature, O<sub>2</sub> concentration, and CaO mass ratio—on NO<sub><em>x</em></sub> generation characteristics during RDF combustion using Response Surface Methodology (RSM). A Box-Behnken experimental design was employed to develop a quadratic regression model for NO<sub><em>x</em></sub> emissions, followed by analysis of variance (ANOVA) and model validation. The results indicate that O<sub>2</sub> concentration has the most significant impact on the peak NO<sub><em>x</em></sub> release (Peak-NO<sub><em>x</em></sub>), with a model F-statistic of 15.76 and a probability value P < 0.01. An increase in O<sub>2</sub> concentration weakens the influence of combustion temperature on Peak-NO<sub><em>x</em></sub>, while an increase in the CaO mass ratio alters the trend of temperature's effect on Peak-NO<sub><em>x</em></sub>. On the other hand, combustion temperature exhibits the greatest influence on total NO<sub><em>x</em></sub> generation (Total-NO<sub><em>x</em></sub>), with parameter interactions being significant only within the 800 °C–900 °C range. The developed models show high goodness-of-fit, with R<sup>2</sup> values of 0.9216 for Peak-NO<sub><em>x</em></sub> and 0.9835 for Total-NO<sub><em>x</em></sub>. Furthermore, multi-objective optimization identified the optimal combustion parameters (884 °C, 13 % O<sub>2</sub>, 6 % CaO), under which Peak-NO<sub><em>x</em></sub> and Total-NO<sub><em>x</em></sub> were reduced to 236 ppm and 0.87 mg, respectively. These findings provide a theoretical foundation and technical guidance for controlling NO<sub><em>x</em></sub> emissions during RDF combustion in precalciners.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102403"},"PeriodicalIF":6.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733438","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 : 2025-12-03DOI: 10.1016/j.joei.2025.102402
Orla Williams , Fatih Gulec , Ho Kwong Lau , Joseph Perkins , Graham O'Brien , Edward Lester
Despite the global push towards net zero, coal remains a dominant energy source in many economies. Biomass co-firing offers coal powered dependent economies a transitional decarbonization pathway, yet co-milling remains a critical barrier due to the contrasting fracture mechanics of coal and biomass and lack of understanding in the partitioning of milled blends. This study aims to overcome some of these challenges by investigating the co-milling behaviour of wood pellets and palm kernel shell (PKS), with 7 coals (5 Australian, 1 Indonesian and 1 Colombian) using a ball and race mill with pneumatic classification. These two biomasses were blended with each coal at 10 % and 40 % wt/wt. The milling performance was evaluated using particle size distribution (PSD) statistical analysis, novel application of thermal characterisation on the milled size fractions, and application of Von Rittinger's comminution theory to rank grindability. Results demonstrate that while PKS exhibits mill choking when milled alone, co-milling enables complete milling, indicating a synergistic effect. Thermogravimetric analysis of size fractions enables the first reported estimation of biomass and coal partitioning within co-milled products. The Von Rittinger constant ranking revealed that softer coals require disproportionately higher energy when blended with biomass, particularly at higher blend ratios. Predictive models based on parent material PSD and thermal composition were developed to estimate co-milled particle size and specific energy consumption, showing good agreement at low blend ratios and highlighting synergistic effects at higher biomass contents. This study provides new insights into the physical and thermal partitioning of co-milled biomass and coal blends, demonstrating that co-milling can mitigate biomass milling limitations and improve throughput. The findings support the development of predictive models for PSD and energy consumption based on the parent material properties, offering practical guidance for the transition towards lower-carbon energy systems.
{"title":"Biomass & coal co-milling: Old hat or the route to decarbonization for coal power dependent economies via novel particle size partitioning analysis","authors":"Orla Williams , Fatih Gulec , Ho Kwong Lau , Joseph Perkins , Graham O'Brien , Edward Lester","doi":"10.1016/j.joei.2025.102402","DOIUrl":"10.1016/j.joei.2025.102402","url":null,"abstract":"<div><div>Despite the global push towards net zero, coal remains a dominant energy source in many economies. Biomass co-firing offers coal powered dependent economies a transitional decarbonization pathway, yet co-milling remains a critical barrier due to the contrasting fracture mechanics of coal and biomass and lack of understanding in the partitioning of milled blends. This study aims to overcome some of these challenges by investigating the co-milling behaviour of wood pellets and palm kernel shell (PKS), with 7 coals (5 Australian, 1 Indonesian and 1 Colombian) using a ball and race mill with pneumatic classification. These two biomasses were blended with each coal at 10 % and 40 % wt/wt. The milling performance was evaluated using particle size distribution (PSD) statistical analysis, novel application of thermal characterisation on the milled size fractions, and application of Von Rittinger's comminution theory to rank grindability. Results demonstrate that while PKS exhibits mill choking when milled alone, co-milling enables complete milling, indicating a synergistic effect. Thermogravimetric analysis of size fractions enables the first reported estimation of biomass and coal partitioning within co-milled products. The Von Rittinger constant ranking revealed that softer coals require disproportionately higher energy when blended with biomass, particularly at higher blend ratios. Predictive models based on parent material PSD and thermal composition were developed to estimate co-milled particle size and specific energy consumption, showing good agreement at low blend ratios and highlighting synergistic effects at higher biomass contents. This study provides new insights into the physical and thermal partitioning of co-milled biomass and coal blends, demonstrating that co-milling can mitigate biomass milling limitations and improve throughput. The findings support the development of predictive models for PSD and energy consumption based on the parent material properties, offering practical guidance for the transition towards lower-carbon energy systems.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102402"},"PeriodicalIF":6.2,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839048","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 : 2025-12-01DOI: 10.1016/j.joei.2025.102400
Francisco Cepeda, Luke Di Liddo, Liam Mendoza, Murray J. Thomson
Microwave-driven methane pyrolysis is a promising pathway for low-GHG hydrogen production. In this process, carbon particles absorb microwave radiation, heat the gas phase, and promote the decomposition of methane. Previous studies hypothesize that localized microplasmas, formed by arcing between conductive particles, may enhance pyrolysis by creating non-thermal excitation of methane molecules. However, the role of microplasmas has not been systematically isolated or quantified. This study investigates the impact of non-thermal plasma discharges on methane conversion and hydrogen yield using a microwave-driven fluidized-bed reactor. Graphitized carbon particles and tungsten electrodes were used to generate intense controlled plasma discharges while maintaining constant microwave power and bulk temperature. Results show that microplasmas induced by graphite alone do not significantly affect methane conversion. In contrast, the addition of unpowered electrodes results in a marked increase in methane conversion (up to 20%) and hydrogen yield. Carbon products formed in the plasma region were characterized by SEM, Raman, and XPS, revealing nanostructured, disordered carbon distinct from thermal film deposits. These findings suggest that only intense, electrode-driven discharges substantially enhance pyrolysis and carbon black production, informing reactor design strategies for efficient hydrogen generation.
{"title":"Plasma-enhanced microwave-driven methane pyrolysis for hydrogen and carbon production","authors":"Francisco Cepeda, Luke Di Liddo, Liam Mendoza, Murray J. Thomson","doi":"10.1016/j.joei.2025.102400","DOIUrl":"10.1016/j.joei.2025.102400","url":null,"abstract":"<div><div>Microwave-driven methane pyrolysis is a promising pathway for low-GHG hydrogen production. In this process, carbon particles absorb microwave radiation, heat the gas phase, and promote the decomposition of methane. Previous studies hypothesize that localized microplasmas, formed by arcing between conductive particles, may enhance pyrolysis by creating non-thermal excitation of methane molecules. However, the role of microplasmas has not been systematically isolated or quantified. This study investigates the impact of non-thermal plasma discharges on methane conversion and hydrogen yield using a microwave-driven fluidized-bed reactor. Graphitized carbon particles and tungsten electrodes were used to generate intense controlled plasma discharges while maintaining constant microwave power and bulk temperature. Results show that microplasmas induced by graphite alone do not significantly affect methane conversion. In contrast, the addition of unpowered electrodes results in a marked increase in methane conversion (up to 20%) and hydrogen yield. Carbon products formed in the plasma region were characterized by SEM, Raman, and XPS, revealing nanostructured, disordered carbon distinct from thermal film deposits. These findings suggest that only intense, electrode-driven discharges substantially enhance pyrolysis and carbon black production, informing reactor design strategies for efficient hydrogen generation.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102400"},"PeriodicalIF":6.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681398","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 : 2025-11-28DOI: 10.1016/j.joei.2025.102384
Evans K. Quaye , Pan Jianfeng , Fan Baowei , Lu Qingbo , Zhang Yi , Jiang Chao , Li Zhongjia , Yang Wenming
The transition to clean fuels is essential for meeting global decarbonization objectives. However, the complex combustion modeling and optimization of these fuels pose significant challenges. Traditional modeling approaches like Computational Fluid Dynamics (CFD), although accurate and foundational, struggle with computational costs, limited scalability, and fidelity trade-offs in combustion systems. This review seeks to evaluate the challenges and transformative potential of combining CFD with Machine Learning (ML) to the combustion of three key candidate fuels in the transition towards a sustainable energy future namely; hydrogen, ammonia, and biofuels. ML techniques including Artificial Neural Network (ANN), Gaussian Processes and Reinforcement Learning, are shown to supplement CFD workflows by accelerating the combustion process and the characteristics of these fuels. Case studies show that CFD-ML hybrid can speed up computations by up to about two orders of magnitude without significantly compromising the accuracy. This enables the real-time optimization of the combustion, mitigate NOx formation, reduce unburned ammonia-slips and addresses the soot formation of biofuels. Despite these advances, unaddressed challenges like data scarcity for high-pressure regimes, interpretability of the so-called black-box ML models, and scalability gaps in industrial applications still exist. The review identifies physics-informed ML models, digital twins, and established critical algorithm selection criteria essential for successfully integrating ML into CFD combustion studies. This interdisciplinary convergence has proven to be an efficient tool in combustion studies while accelerating the design of carbon-neutral energy systems. The study therefore harnesses CFD-ML synergy for applications in modeling sustainable combustion technologies for power generation, aviation, and heavy industry.
{"title":"A review of hybrid computational fluid dynamics and machine learning approaches for the combustion of alternative fuels","authors":"Evans K. Quaye , Pan Jianfeng , Fan Baowei , Lu Qingbo , Zhang Yi , Jiang Chao , Li Zhongjia , Yang Wenming","doi":"10.1016/j.joei.2025.102384","DOIUrl":"10.1016/j.joei.2025.102384","url":null,"abstract":"<div><div>The transition to clean fuels is essential for meeting global decarbonization objectives. However, the complex combustion modeling and optimization of these fuels pose significant challenges. Traditional modeling approaches like Computational Fluid Dynamics (CFD), although accurate and foundational, struggle with computational costs, limited scalability, and fidelity trade-offs in combustion systems. This review seeks to evaluate the challenges and transformative potential of combining CFD with Machine Learning (ML) to the combustion of three key candidate fuels in the transition towards a sustainable energy future namely; hydrogen, ammonia, and biofuels. ML techniques including Artificial Neural Network (ANN), Gaussian Processes and Reinforcement Learning, are shown to supplement CFD workflows by accelerating the combustion process and the characteristics of these fuels. Case studies show that CFD-ML hybrid can speed up computations by up to about two orders of magnitude without significantly compromising the accuracy. This enables the real-time optimization of the combustion, mitigate NOx formation, reduce unburned ammonia-slips and addresses the soot formation of biofuels. Despite these advances, unaddressed challenges like data scarcity for high-pressure regimes, interpretability of the so-called black-box ML models, and scalability gaps in industrial applications still exist. The review identifies physics-informed ML models, digital twins, and established critical algorithm selection criteria essential for successfully integrating ML into CFD combustion studies. This interdisciplinary convergence has proven to be an efficient tool in combustion studies while accelerating the design of carbon-neutral energy systems. The study therefore harnesses CFD-ML synergy for applications in modeling sustainable combustion technologies for power generation, aviation, and heavy industry.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102384"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681415","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}
This study evaluates the performance of newly developed MnO2/CeO2-KIT-6 and MnO2/CeO2-SBA-15 catalysts for NO reduction via the NH3-SCR process. The catalysts were thoroughly characterized using a range of techniques, including Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. XRD analysis revealed a cubic phase structure in both CeO2 and MnO2. Among the two, the MnO2/CeO2-KIT-6 catalyst showed the highest contents of Ce3+ (54.0 %), Mn4+ (71.0 %), and surface adsorbed oxygen (75.4 %). Catalytic activity tests demonstrated that MnO2/CeO2-KIT-6 outperformed MnO2/CeO2-SBA-15 across a temperature range of 50–450 °C, achieving a maximum NO conversion of 75 % and N2 selectivity of 86 % at 250 °C. Furthermore, increasing the MnO2 loading in the (20 wt%) MnO2/CeO2-KIT-6 catalyst improved NO conversion and N2 selectivity, reaching 80 % and nearly 89 %, respectively.
{"title":"Study of mesoporous silica-supported catalysts for the selective catalytic reduction of NOx using NH3 as reducing agent","authors":"Shyam Sunder Rao, Rohit Kumar Yadav, Vivek Kumar Patel, Abhishek Anand, Sweta Sharma","doi":"10.1016/j.joei.2025.102386","DOIUrl":"10.1016/j.joei.2025.102386","url":null,"abstract":"<div><div>This study evaluates the performance of newly developed MnO<sub>2</sub>/CeO<sub>2</sub>-KIT-6 and MnO<sub>2</sub>/CeO<sub>2</sub>-SBA-15 catalysts for NO reduction via the NH<sub>3</sub>-SCR process. The catalysts were thoroughly characterized using a range of techniques, including Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. XRD analysis revealed a cubic phase structure in both CeO<sub>2</sub> and MnO<sub>2</sub>. Among the two, the MnO<sub>2</sub>/CeO<sub>2</sub>-KIT-6 catalyst showed the highest contents of Ce<sup>3+</sup> (54.0 %), Mn<sup>4+</sup> (71.0 %), and surface adsorbed oxygen (75.4 %). Catalytic activity tests demonstrated that MnO<sub>2</sub>/CeO<sub>2</sub>-KIT-6 outperformed MnO<sub>2</sub>/CeO<sub>2</sub>-SBA-15 across a temperature range of 50–450 °C, achieving a maximum NO conversion of 75 % and N<sub>2</sub> selectivity of 86 % at 250 °C. Furthermore, increasing the MnO<sub>2</sub> loading in the (20 wt%) MnO<sub>2</sub>/CeO<sub>2</sub>-KIT-6 catalyst improved NO conversion and N<sub>2</sub> selectivity, reaching 80 % and nearly 89 %, respectively.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102386"},"PeriodicalIF":6.2,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681403","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 : 2025-11-26DOI: 10.1016/j.joei.2025.102399
Birce Pekmezci Karaman , Nuray Oktar , Fatih Güleç
Achieving a net-zero carbon future necessitates the development of sustainable biofuels as alternatives to fossil-derived transportation fuels. However, the direct use of raw bio-oil is limited by its high oxygen content, chemical instability, and corrosiveness, making catalytic upgrading to hydrocarbon-rich fuels essential. Conventional catalysts for bio-oil upgrading often suffer from poor selectivity, rapid deactivation due to coke formation, or insufficient resistance to the complex oxygenates present in bio-oil. This study investigates the catalytic upgrading of biomass-derived bio-oil using novel mesoporous silica-based microsphere catalysts functionalized with manganese (Mn) and cerium (Ce) via a microencapsulation technique, which enhances metal dispersion and redox properties. Catalytic activity tests were carried out at 400 °C under atmospheric pressure using a model bio-oil mixture (furfural, formic acid, and hydroxypropanol) co-fed with ethanol at a 70:30 volumetric ratio. The results show that Mn-functionalized mesoporous silica microspheres (SMC) achieve 94 % conversion and high isoparaffin selectivity (71 %). Moreover, the synergistic incorporation of Ce introduces enhanced redox behavior and oxygen-vacancy sites in addition to drastically suppressing coke formation, which decreased from ∼22 wt% (unmodified SMC) to 1.4 wt% (5Ce@5Mn-SMC). These results indicate that Mn- and Ce-functionalized silica microspheres exhibit high catalytic activity and long-term stability, providing better performance in converting oxygen-rich bio-oil into high-quality hydrocarbon fuels.
{"title":"Synergistic Mn–Ce modification of mesoporous silica microspheres for deoxygenation of bio-oil to biofuel","authors":"Birce Pekmezci Karaman , Nuray Oktar , Fatih Güleç","doi":"10.1016/j.joei.2025.102399","DOIUrl":"10.1016/j.joei.2025.102399","url":null,"abstract":"<div><div>Achieving a net-zero carbon future necessitates the development of sustainable biofuels as alternatives to fossil-derived transportation fuels. However, the direct use of raw bio-oil is limited by its high oxygen content, chemical instability, and corrosiveness, making catalytic upgrading to hydrocarbon-rich fuels essential. Conventional catalysts for bio-oil upgrading often suffer from poor selectivity, rapid deactivation due to coke formation, or insufficient resistance to the complex oxygenates present in bio-oil. This study investigates the catalytic upgrading of biomass-derived bio-oil using novel mesoporous silica-based microsphere catalysts functionalized with manganese (Mn) and cerium (Ce) via a microencapsulation technique, which enhances metal dispersion and redox properties. Catalytic activity tests were carried out at 400 °C under atmospheric pressure using a model bio-oil mixture (furfural, formic acid, and hydroxypropanol) co-fed with ethanol at a 70:30 volumetric ratio. The results show that Mn-functionalized mesoporous silica microspheres (SMC) achieve 94 % conversion and high isoparaffin selectivity (71 %). Moreover, the synergistic incorporation of Ce introduces enhanced redox behavior and oxygen-vacancy sites in addition to drastically suppressing coke formation, which decreased from ∼22 wt% (unmodified SMC) to 1.4 wt% (5Ce@5Mn-SMC). These results indicate that Mn- and Ce-functionalized silica microspheres exhibit high catalytic activity and long-term stability, providing better performance in converting oxygen-rich bio-oil into high-quality hydrocarbon fuels.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102399"},"PeriodicalIF":6.2,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614597","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 : 2025-11-26DOI: 10.1016/j.joei.2025.102390
Yutong Hu, Hai Zhang, Wenyang Liu, Kai Wang, Chuanjin Zhao, Weidong Fan
Ammonia combustion is crucial due to its promise as a renewable energy source and its ability to curb greenhouse gas emissions in power generation sector. The pre-decomposition of NH3 is evidenced to be an important modification for the improvement of the NH3 combustion. However, the detailed mechanisms behind this improvement remains unclear. In this work, focus is directed on the enhancement mechanisms of the pre-decomposition of NH3 based on the application of the Reactive Force Field Molecular Dynamics (ReaxFF MD) modelling through comprehensive understanding on the effect of temperature (T = 2500–3500 K), excess air coefficient (λ = 1.0–1.3), staged ratio (α = 0.2–0.8), and decomposition ratio (β = 0.5–0.9) on the encompassed kinetics and mechanisms. The results show that pre-decomposition reduces combustion time (notably at β < 0.7) and lowers activation energy. A trade-off between H2O and NOx emissions emerges, where H2O suppresses NO via OH-mediated inhibition of N2+O→NO + N. Increasing β (0.5 → 0.9, α = 0.2) boosts HNO→NO but amplifies NO→N2 and H2N2→N2, yielding net NO reduction. Raising α to 0.5 suppresses HNO→NO while enhancing NH3→NH2 and NH2→N2, favoring N2 stability. Besides, pre-decomposed combustion effectively suppresses NOx emissions.The results from the present work will provide great support for the industrial adjustable strategies with efficient and low-NOx combustion of NH3.
{"title":"The effect of the pre-decomposition of NH3 on its combustion performance: A ReaxFF study","authors":"Yutong Hu, Hai Zhang, Wenyang Liu, Kai Wang, Chuanjin Zhao, Weidong Fan","doi":"10.1016/j.joei.2025.102390","DOIUrl":"10.1016/j.joei.2025.102390","url":null,"abstract":"<div><div>Ammonia combustion is crucial due to its promise as a renewable energy source and its ability to curb greenhouse gas emissions in power generation sector. The pre-decomposition of NH<sub>3</sub> is evidenced to be an important modification for the improvement of the NH<sub>3</sub> combustion. However, the detailed mechanisms behind this improvement remains unclear. In this work, focus is directed on the enhancement mechanisms of the pre-decomposition of NH<sub>3</sub> based on the application of the Reactive Force Field Molecular Dynamics (ReaxFF MD) modelling through comprehensive understanding on the effect of temperature (T = 2500–3500 K), excess air coefficient (λ = 1.0–1.3), staged ratio (α = 0.2–0.8), and decomposition ratio (β = 0.5–0.9) on the encompassed kinetics and mechanisms. The results show that pre-decomposition reduces combustion time (notably at β < 0.7) and lowers activation energy. A trade-off between H<sub>2</sub>O and NO<sub>x</sub> emissions emerges, where H<sub>2</sub>O suppresses NO via OH-mediated inhibition of N<sub>2</sub>+O→NO + N. Increasing β (0.5 → 0.9, α = 0.2) boosts HNO→NO but amplifies NO→N<sub>2</sub> and H<sub>2</sub>N<sub>2</sub>→N<sub>2</sub>, yielding net NO reduction. Raising α to 0.5 suppresses HNO→NO while enhancing NH<sub>3</sub>→NH<sub>2</sub> and NH<sub>2</sub>→N<sub>2</sub>, favoring N<sub>2</sub> stability. Besides, pre-decomposed combustion effectively suppresses NO<sub>x</sub> emissions.The results from the present work will provide great support for the industrial adjustable strategies with efficient and low-NO<sub>x</sub> combustion of NH<sub>3</sub>.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102390"},"PeriodicalIF":6.2,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614632","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 : 2025-11-26DOI: 10.1016/j.joei.2025.102385
Kaixuan Yang , Yaoyao Ying , Dandan Qi , Runtian Yu , Chen Chen , Mingxiao Chen , Jianhua Yan , Dong Liu
This study investigated the magnetic influence on soot characteristics in CO2/N2 diluted ethylene inverse diffusion flames (IDF). The response of flame structure and soot properties to various magnetic conditions, as well as the type of diluent (nitrogen and carbon dioxide) and oxygen concentration in oxidizer was examined in this work. High-resolution transmission electron microscopy analysis (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy analysis were employed to investigate the nanostructure and graphitic level of soot derived from the exhaust gas of CO2/N2 diluted flame under various magnetic conditions. The results illustrated that the CO2 diluted flame displayed a reduced yellow sooting regions in comparison to the flame with N2 dilution, suggesting a lower soot formation. Additionally, the soot particles produced by CO2-doped flames demonstrated lower graphitization level in contrast to those generated from N2 diluted flames. Notably, applying an upward magnetic gradient to the CO2-doped flame could facilitate the conversion of amorphous structures into fullerene-like structures within the soot nanostructure. In both CO2 and N2 diluted flames, as increasing magnetic flux density, the soot nanostructure exhibited lower fringe tortuosity, longer fringe lengths and more graphitic carbon content. These results suggested that regardless of whether N2 or CO2 was used as the diluent, the imposed upward magnetic gradient enhance the graphitic degree of soot. This enhancement might be caused by the magnetic force-induced redistribution of oxygen in the flame, which in turn resulted in longer residence time of soot within the flame and additional oxidation of soot particles.
{"title":"Regulation of soot properties via the combined effects of carbon dioxide and magnetic fields in ethylene inverse diffusion flames","authors":"Kaixuan Yang , Yaoyao Ying , Dandan Qi , Runtian Yu , Chen Chen , Mingxiao Chen , Jianhua Yan , Dong Liu","doi":"10.1016/j.joei.2025.102385","DOIUrl":"10.1016/j.joei.2025.102385","url":null,"abstract":"<div><div>This study investigated the magnetic influence on soot characteristics in CO<sub>2</sub>/N<sub>2</sub> diluted ethylene inverse diffusion flames (IDF). The response of flame structure and soot properties to various magnetic conditions, as well as the type of diluent (nitrogen and carbon dioxide) and oxygen concentration in oxidizer was examined in this work. High-resolution transmission electron microscopy analysis (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy analysis were employed to investigate the nanostructure and graphitic level of soot derived from the exhaust gas of CO<sub>2</sub>/N<sub>2</sub> diluted flame under various magnetic conditions. The results illustrated that the CO<sub>2</sub> diluted flame displayed a reduced yellow sooting regions in comparison to the flame with N<sub>2</sub> dilution, suggesting a lower soot formation. Additionally, the soot particles produced by CO<sub>2</sub>-doped flames demonstrated lower graphitization level in contrast to those generated from N<sub>2</sub> diluted flames. Notably, applying an upward magnetic gradient to the CO<sub>2</sub>-doped flame could facilitate the conversion of amorphous structures into fullerene-like structures within the soot nanostructure. In both CO<sub>2</sub> and N<sub>2</sub> diluted flames, as increasing magnetic flux density, the soot nanostructure exhibited lower fringe tortuosity, longer fringe lengths and more graphitic carbon content. These results suggested that regardless of whether N<sub>2</sub> or CO<sub>2</sub> was used as the diluent, the imposed upward magnetic gradient enhance the graphitic degree of soot. This enhancement might be caused by the magnetic force-induced redistribution of oxygen in the flame, which in turn resulted in longer residence time of soot within the flame and additional oxidation of soot particles.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102385"},"PeriodicalIF":6.2,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681400","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}
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