Pub Date : 2025-12-10DOI: 10.1016/j.joei.2025.102414
Tianxing Zhou, Dongliang Wei, Huaan Li, Hao Zhou
As environmental pollution issues become increasingly severe, controlling nitrogen oxide (NOx) emissions during combustion has emerged as a key research focus. This study investigates the effects of air-staging strategies on methane-ammonia blended combustion flames and NOx emission mechanisms through a combination of experimental and simulation approaches. Results indicate that staged air combustion effectively reduces NO emissions, particularly at a staging ratio of 30 %, where NO emissions decrease by 85.4 %. However, staging ratios exceeding 30 % may compromise flame stability and even increase NO emissions. NO emissions are effectively controlled by maintaining an enriched combustion state in the primary combustion zone, thereby reducing NO formation via the HNO pathway and enhancing NO consumption via the NHi pathway. The optimised staged ratio is 36 %; exceeding this value may cause significant NO production in the secondary combustion zone. Furthermore, the chemical reactor network model further reveals the primary reaction pathways for NO emissions, confirming the positive effect of increasing primary combustion zone residence time on reducing NO emissions.
{"title":"Study on NO emission mechanism of CH4-NH3 blended combustion based on air-classification strategy","authors":"Tianxing Zhou, Dongliang Wei, Huaan Li, Hao Zhou","doi":"10.1016/j.joei.2025.102414","DOIUrl":"10.1016/j.joei.2025.102414","url":null,"abstract":"<div><div>As environmental pollution issues become increasingly severe, controlling nitrogen oxide (NOx) emissions during combustion has emerged as a key research focus. This study investigates the effects of air-staging strategies on methane-ammonia blended combustion flames and NOx emission mechanisms through a combination of experimental and simulation approaches. Results indicate that staged air combustion effectively reduces NO emissions, particularly at a staging ratio of 30 %, where NO emissions decrease by 85.4 %. However, staging ratios exceeding 30 % may compromise flame stability and even increase NO emissions. NO emissions are effectively controlled by maintaining an enriched combustion state in the primary combustion zone, thereby reducing NO formation via the HNO pathway and enhancing NO consumption via the NHi pathway. The optimised staged ratio is 36 %; exceeding this value may cause significant NO production in the secondary combustion zone. Furthermore, the chemical reactor network model further reveals the primary reaction pathways for NO emissions, confirming the positive effect of increasing primary combustion zone residence time on reducing NO emissions.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102414"},"PeriodicalIF":6.2,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786496","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 : 2025-12-10DOI: 10.1016/j.joei.2025.102419
Md Rajib Hossain , Rendong Zheng , Yuyang Long , Yuxuan Ying , Mi Yan
The environmental risks posed by heavy metals in municipal solid waste incineration fly ash are a critical concern, requiring effective safety training and disposal strategies. This study examined the combination of pre-washing with hydrothermal treatment to remove heavy metals and recover salts from fly ash. The samples were analyzed using XRF, XRD, SEM, BET, and ICP-MS to assess the effect of combined treatment on heavy-metal stabilization. Hydrothermal conditions were varied in terms of temperature, liquid-to-solid (L/S) ratio, duration, and additives (H2O2 and HCl) to enhance metal immobilization and reduce the leachability of As, Pb, Cr, Cd, Ni, and Zn. Pre-washing removed up to 85 % of salts, reducing dissolved solids. After hydrothermal treatment, inorganic reagents Na2S and Na3PO4 were used to separate heavy metals from the highly toxic, high-salt wastewater phase. The experimental results demonstrate that pre-washing combined with hydrothermal treatment (210 °C, 15min, 5:1 L/S ratio, and 2 mol/L HCl) is suitable for leaching heavy metals from fly ash by forming zeolites that stabilize them. Na2S and HCl treatments optimized salt recovery, indicated by increased sodium salt extraction. Multivariate analyses, including correlation heatmaps, PCA, and cluster analysis, were performed after hydrothermal treatment to explore relationships among heavy metals. Overall, this combined process offers a promising approach for removing heavy metals, enhancing resource recovery, and reducing environmental risks associated with fly ash disposal.
{"title":"Optimization of heavy metal removal and salt recovery from MSWI fly ash through pre-washing combined with hydrothermal treatment","authors":"Md Rajib Hossain , Rendong Zheng , Yuyang Long , Yuxuan Ying , Mi Yan","doi":"10.1016/j.joei.2025.102419","DOIUrl":"10.1016/j.joei.2025.102419","url":null,"abstract":"<div><div>The environmental risks posed by heavy metals in municipal solid waste incineration fly ash are a critical concern, requiring effective safety training and disposal strategies. This study examined the combination of pre-washing with hydrothermal treatment to remove heavy metals and recover salts from fly ash. The samples were analyzed using XRF, XRD, SEM, BET, and ICP-MS to assess the effect of combined treatment on heavy-metal stabilization. Hydrothermal conditions were varied in terms of temperature, liquid-to-solid (L/S) ratio, duration, and additives (H<sub>2</sub>O<sub>2</sub> and HCl) to enhance metal immobilization and reduce the leachability of As, Pb, Cr, Cd, Ni, and Zn. Pre-washing removed up to 85 % of salts, reducing dissolved solids. After hydrothermal treatment, inorganic reagents Na<sub>2</sub>S and Na<sub>3</sub>PO<sub>4</sub> were used to separate heavy metals from the highly toxic, high-salt wastewater phase. The experimental results demonstrate that pre-washing combined with hydrothermal treatment (210 °C, 15min, 5:1 L/S ratio, and 2 mol/L HCl) is suitable for leaching heavy metals from fly ash by forming zeolites that stabilize them. Na<sub>2</sub>S and HCl treatments optimized salt recovery, indicated by increased sodium salt extraction. Multivariate analyses, including correlation heatmaps, PCA, and cluster analysis, were performed after hydrothermal treatment to explore relationships among heavy metals. Overall, this combined process offers a promising approach for removing heavy metals, enhancing resource recovery, and reducing environmental risks associated with fly ash disposal.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102419"},"PeriodicalIF":6.2,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733334","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 : 2025-12-09DOI: 10.1016/j.joei.2025.102405
Yuzheng Gao , Zhijie Liu , Youping Li , Shixuan Yang , Han Jiang , Huayang Zhao , Yiran Zhang , He Lin
During the co-combustion of ammonia and carbon-containing fuels, toxic nitrogenous species such as N2O and NO are formed. However, the formation and conversion mechanisms of these pollutants in ammonia co-combustion processes remain insufficiently understood, hindering the advancement and practical application of ammonia-fueled energy systems. In this study, ReaxFF molecular dynamics simulations combined with chemical kinetic analysis were employed to investigate the formation and conversion mechanisms of NO and N2O over the temperature range of 700K–1400K. This study highlights the critical role of NH in the conversion processes of NO and N2O. Three primary pathways for the conversion of NO and N2O are proposed: (i) direct interconversion between NO and N2O; (ii) conversion driven by precursor concentrations; (iii) competition between oxidation pathways regulated by C-N interactions. All of these pathways are facilitated by the reaction NH + CO2 = HNO + CO. Additionally, different fuel types inhibit the formation and conversion of NO and N2O through distinct mechanistic pathways. In pure ammonia combustion, direct NO and N2O conversion is primarily suppressed under high-pressure conditions; in NH3-DME combustion, suppression occurs mainly via water addition; in NH3-CH4 combustion, inhibition is predominantly achieved by limiting precursor formation under oxygen-rich conditions; and in NH3-CH3OH combustion, direct NO and N2O conversion is primarily restrained under the synergistic effects of high temperature and high pressure. It provides a theoretical foundation for achieving synergistic pollutant inhibition across temperature domains in ammonia-based combustion systems operating under variable loads and with multiple fuels.
氨与含碳燃料共燃烧时，会形成N2O、NO等有毒含氮物质。然而，这些污染物在氨共燃过程中的形成和转化机制尚不清楚，阻碍了氨燃料能源系统的发展和实际应用。本研究采用ReaxFF分子动力学模拟和化学动力学分析相结合的方法，研究了在700K-1400K温度范围内NO和N2O的形成和转化机理。本研究强调了NH在NO和N2O转化过程中的关键作用。本文提出了NO和N2O转化的三种主要途径：(i) NO和N2O之间的直接相互转化；由前体浓度驱动的转化；（iii）由碳氮相互作用调控的氧化途径之间的竞争。NH + CO2 = HNO + CO的反应促进了这些途径的形成，不同的燃料类型通过不同的机制途径抑制NO和N2O的形成和转化。在纯氨燃烧中，高压条件下主要抑制NO和N2O的直接转化；NH3-DME燃烧主要通过加水抑制；在NH3-CH4燃烧过程中，抑制作用主要通过富氧条件下限制前驱体的形成来实现；在NH3-CH3OH燃烧过程中，高温高压的协同作用主要抑制NO和N2O的直接转化。它为在变负荷和多种燃料下运行的氨基燃烧系统中实现跨温度域的协同污染物抑制提供了理论基础。
{"title":"Unveiling the conversion mechanisms of NO and N2O in ammonia blending combustion under high pressure, oxygen enrichment, and H2O addition conditions","authors":"Yuzheng Gao , Zhijie Liu , Youping Li , Shixuan Yang , Han Jiang , Huayang Zhao , Yiran Zhang , He Lin","doi":"10.1016/j.joei.2025.102405","DOIUrl":"10.1016/j.joei.2025.102405","url":null,"abstract":"<div><div>During the co-combustion of ammonia and carbon-containing fuels, toxic nitrogenous species such as N<sub>2</sub>O and NO are formed. However, the formation and conversion mechanisms of these pollutants in ammonia co-combustion processes remain insufficiently understood, hindering the advancement and practical application of ammonia-fueled energy systems. In this study, ReaxFF molecular dynamics simulations combined with chemical kinetic analysis were employed to investigate the formation and conversion mechanisms of NO and N<sub>2</sub>O over the temperature range of 700K–1400K. This study highlights the critical role of NH in the conversion processes of NO and N<sub>2</sub>O. Three primary pathways for the conversion of NO and N<sub>2</sub>O are proposed: (i) direct interconversion between NO and N<sub>2</sub>O; (ii) conversion driven by precursor concentrations; (iii) competition between oxidation pathways regulated by C-N interactions. All of these pathways are facilitated by the reaction NH + CO<sub>2</sub> = HNO + CO. Additionally, different fuel types inhibit the formation and conversion of NO and N<sub>2</sub>O through distinct mechanistic pathways. In pure ammonia combustion, direct NO and N<sub>2</sub>O conversion is primarily suppressed under high-pressure conditions; in NH<sub>3</sub>-DME combustion, suppression occurs mainly via water addition; in NH<sub>3</sub>-CH<sub>4</sub> combustion, inhibition is predominantly achieved by limiting precursor formation under oxygen-rich conditions; and in NH<sub>3</sub>-CH<sub>3</sub>OH combustion, direct NO and N<sub>2</sub>O conversion is primarily restrained under the synergistic effects of high temperature and high pressure. It provides a theoretical foundation for achieving synergistic pollutant inhibition across temperature domains in ammonia-based combustion systems operating under variable loads and with multiple fuels.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102405"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733439","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 : 2025-12-09DOI: 10.1016/j.joei.2025.102409
Chunxu Ma , Bang Cui , Yanfei Du , Zhou Yu , Jianguo Du , Yu Wang
Co-firing hydrogen or ammonia with coal offers a viable pathway for reducing carbon emissions in pulverized coal combustion, yet strategies for achieving low-NOx emissions remain insufficiently understood. This study investigates the effects of fuel properties and air-staging on NOx formation during ammonia–coal and hydrogen–coal co-firing in a 50-kW wall-temperature-controlled drop-tube furnace, supported by chemical reactor network (CRN) modeling. Results show contrasting behaviors: in ammonia–coal co-firing, NO emission increases monotonically with higher ammonia blending ratios, whereas in hydrogen–coal co-firing, NO decreases initially and become stabilizing when the hydrogen fraction exceeds 20 %. Air staging significantly suppresses NO formation in both systems, but the two carbon-free fuels display distinct sensitivities to the primary combustion zone's excess air ratio (α1). Ammonia–coal co-firing requires precise control of α1 to minimize emissions, while hydrogen–coal co-firing only demands maintenance of a fuel-rich primary zone (α1 < 1). Reaction pathway analysis reveals that NO formation predominantly originates from the NHi pathway, with competitive reactions among HNO, NH2, NH, and N determining whether nitrogen converts to N2 or NO. These findings clarify the mechanisms by which air staging mitigates NO and provide critical guidance for tailoring low-NOx strategies in industrial ammonia–coal and hydrogen–coal co-firing applications.
{"title":"NOx formation in pulverized coal co-firing with ammonia and hydrogen: effects of fuel properties and air-staging","authors":"Chunxu Ma , Bang Cui , Yanfei Du , Zhou Yu , Jianguo Du , Yu Wang","doi":"10.1016/j.joei.2025.102409","DOIUrl":"10.1016/j.joei.2025.102409","url":null,"abstract":"<div><div>Co-firing hydrogen or ammonia with coal offers a viable pathway for reducing carbon emissions in pulverized coal combustion, yet strategies for achieving low-NOx emissions remain insufficiently understood. This study investigates the effects of fuel properties and air-staging on NOx formation during ammonia–coal and hydrogen–coal co-firing in a 50-kW wall-temperature-controlled drop-tube furnace, supported by chemical reactor network (CRN) modeling. Results show contrasting behaviors: in ammonia–coal co-firing, NO emission increases monotonically with higher ammonia blending ratios, whereas in hydrogen–coal co-firing, NO decreases initially and become stabilizing when the hydrogen fraction exceeds 20 %. Air staging significantly suppresses NO formation in both systems, but the two carbon-free fuels display distinct sensitivities to the primary combustion zone's excess air ratio (α<sub>1</sub>). Ammonia–coal co-firing requires precise control of α<sub>1</sub> to minimize emissions, while hydrogen–coal co-firing only demands maintenance of a fuel-rich primary zone (α<sub>1</sub> < 1). Reaction pathway analysis reveals that NO formation predominantly originates from the NH<sub><em>i</em></sub> pathway, with competitive reactions among HNO, NH<sub>2</sub>, NH, and N determining whether nitrogen converts to N<sub>2</sub> or NO. These findings clarify the mechanisms by which air staging mitigates NO and provide critical guidance for tailoring low-NOx strategies in industrial ammonia–coal and hydrogen–coal co-firing applications.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102409"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733430","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 comprehensively investigates the source, distribution, emission, and control of n-alkanes (C16 ∼ C34) and priority phthalate esters (PAEs) within condensable particulate matter (CPM) from an ultralow emission coal-fired power plant. Systematic sampling across the sequential air pollution control devices (APCDs) system (SCR, LLT-ESP, WFGD, WESP) elucidated the migration mechanism of complex pollutants: significant overall removal (69.18 % n-alkanes, 69.92 % PAEs) was achieved, driven primarily by the LLT-ESP (75.46 % and 70.42 %, respectively) benefiting from MGGH-induced cooling. However, pollutant secondary formation occurred in the SCR (2.09 % n-alkanes, 11.66 % PAEs). Co-firing 10 % municipal sewage sludge (MSS) increased stack n-alkanes (491.62–510.55 μg/m3) and PAEs (147.53–154.03 μg/m3) emissions due to altered combustion and inherent sludge organics. Adsorbent injection (coconut-shell based activated carbon abbreviated as ACY, wood-based activated carbon abbreviated as ACM) upstream of the LLT-ESP significantly enhanced removal performance under harsh conditions (high SO2/dust, 101 ± 4 °C). ACY at 150 mg/Nm3 yielded optimal performance (31.03 % n-alkanes, 23.88 % PAEs removal), attributed to superior textural properties (1282 m2/g surface area) and surface oxygen functionality. This work provides critical insights and engineering data for controlling organic pollutants in CPM.
{"title":"Emission and control of n-alkanes and phthalate esters in condensable particulate matter from an ultralow emission coal-fired power plant","authors":"Zhenyao Xu , Yueqiong Wu , Yujia Wu , Jinchao Zhao , Yunlong Zhao , Shengyong Lu , Hongbo Xu","doi":"10.1016/j.joei.2025.102408","DOIUrl":"10.1016/j.joei.2025.102408","url":null,"abstract":"<div><div>This study comprehensively investigates the source, distribution, emission, and control of n-alkanes (C<sub>16</sub> ∼ C<sub>34</sub>) and priority phthalate esters (PAEs) within condensable particulate matter (CPM) from an ultralow emission coal-fired power plant. Systematic sampling across the sequential air pollution control devices (APCDs) system (SCR, LLT-ESP, WFGD, WESP) elucidated the migration mechanism of complex pollutants: significant overall removal (69.18 % n-alkanes, 69.92 % PAEs) was achieved, driven primarily by the LLT-ESP (75.46 % and 70.42 %, respectively) benefiting from MGGH-induced cooling. However, pollutant secondary formation occurred in the SCR (2.09 % n-alkanes, 11.66 % PAEs). Co-firing 10 % municipal sewage sludge (MSS) increased stack n-alkanes (491.62–510.55 μg/m<sup>3</sup>) and PAEs (147.53–154.03 μg/m<sup>3</sup>) emissions due to altered combustion and inherent sludge organics. Adsorbent injection (coconut-shell based activated carbon abbreviated as ACY, wood-based activated carbon abbreviated as ACM) upstream of the LLT-ESP significantly enhanced removal performance under harsh conditions (high SO<sub>2</sub>/dust, 101 ± 4 °C). ACY at 150 mg/Nm<sup>3</sup> yielded optimal performance (31.03 % n-alkanes, 23.88 % PAEs removal), attributed to superior textural properties (1282 m<sup>2</sup>/g surface area) and surface oxygen functionality. This work provides critical insights and engineering data for controlling organic pollutants in CPM.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102408"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733431","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}
In the context of energy demand, green hydrogen energy is a significant trend, playing a crucial role in various applications due to its pollution-free nature, improved efficiency, and superior fuel economy compared to fossil fuels. Here, the study involves producing the hydrogen syngas from food/kitchen waste water via supercritical water gasification (SCWG) methods. The experimentation is conducted with different gasification pressures (10–25 MPa) at a constant gasification temperature (550 °C) and residence time (30 min) using both Ru-based catalysts (1 wt% Ru) and Ru/Al2O3-supported catalysts. The experimentation results show that the improved pressure of gasification leads to a progressive enhancement in hydrogen syngas yield, better carbon conversion efficiency, gasification efficiency, and reduced tar formation. Furthermore, the setup configured with Ru/Al2O3-supported catalysts achieves 27.1 % of hydrogen yield, increases carbon conversion efficiency (5.2 %), optimizes gasification efficiency (7.8 %), and reduces tar formation by 21.2 % compared to the supercritical water gasification setup without a catalyst. This combination of an operated supercritical gasification system with higher gasification pressure is a trade-off for hydrogen syngas production from food/kitchen waste water, resulting in reduced tar and improved hydrogen gas formation.
{"title":"Extraction of sustainable green hydrogen energy through supercritical water gasification activated with Ru/alumina","authors":"Gopal Kaliyaperumal , Nagabhooshanam Nagarajan , Yogendra Thakur , Abhilasha Jadhav , Ramesh Kumar Chandrasekhar , Guddati Vijaya Lakshmi , Ramya Maranan , R. Venkatesh , S. Sathiyamurthy , Senthil Kumar Vishnu","doi":"10.1016/j.joei.2025.102411","DOIUrl":"10.1016/j.joei.2025.102411","url":null,"abstract":"<div><div>In the context of energy demand, green hydrogen energy is a significant trend, playing a crucial role in various applications due to its pollution-free nature, improved efficiency, and superior fuel economy compared to fossil fuels. Here, the study involves producing the hydrogen syngas from food/kitchen waste water via supercritical water gasification (SCWG) methods. The experimentation is conducted with different gasification pressures (10–25 MPa) at a constant gasification temperature (550 °C) and residence time (30 min) using both Ru-based catalysts (1 wt% Ru) and Ru/Al<sub>2</sub>O<sub>3</sub>-supported catalysts. The experimentation results show that the improved pressure of gasification leads to a progressive enhancement in hydrogen syngas yield, better carbon conversion efficiency, gasification efficiency, and reduced tar formation. Furthermore, the setup configured with Ru/Al<sub>2</sub>O<sub>3</sub>-supported catalysts achieves 27.1 % of hydrogen yield, increases carbon conversion efficiency (5.2 %), optimizes gasification efficiency (7.8 %), and reduces tar formation by 21.2 % compared to the supercritical water gasification setup without a catalyst. This combination of an operated supercritical gasification system with higher gasification pressure is a trade-off for hydrogen syngas production from food/kitchen waste water, resulting in reduced tar and improved hydrogen gas formation.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102411"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733432","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 : 2025-12-09DOI: 10.1016/j.joei.2025.102406
Yawei Song , Qifu Lin , Sheng Su , Longwei Chen , Chengzhou Liu , Weiye Chen , Zhenyang Li , Yiman Jiang , Dianwu Wu , Hansheng Feng , Yangjiong Liu , Guangnan Luo , Jun Xiang
Ammonia injection location and ammonia-coal blending method significantly affect boiler combustion performance and pollutant emissions, yet their synergistic effects remain unclear. To investigate this synergistic effect, six cases of 20 % ammonia co-firing with coal were simulated in a 330 MW tangentially fired boiler, including pure coal and ammonia-coal co-injection through four-layer burners, as well as in-burner and in-boiler blending using burners at two different heights. The temperature distribution, coal burnout behaviors, and NOx generation characteristics were obtained. The results showed that the ammonia injection location and fuel blending method jointly influence the high-temperature distribution in the main combustion zone. With upper ammonia injection, the in-burner blending shifts the high-temperature zone to the upper of main combustion zone and its downstream regions, whereas in-boiler blending confines it to the bottom. However, bottom injection exhibits the opposite trend. These higher-temperature areas corresponded to increased concentrations of H2O and CO2, enhancing thermal radiation and heat transfer. Ammonia injection through either the upper or bottom burner using the in-boiler blending method increased the peak coal burnout rate and narrowed the half-peak width in the main combustion zone. However, compared with upper injection, bottom ammonia injection shifted the burnout peak toward the reduction zone, likely due to lower temperatures from pure ammonia combustion that hinder coal ignition. Although the NO concentrations were comparable between the two fuel blending methods regardless of injection location, the NO formation and reduction rates varied with combination of injection position and blending method. Specifically, with bottom ammonia injection, in-boiler blending yielded a higher NO reduction rate by NH3, while in-burner blending led to greater fuel-NO formation. For upper injection, however, the NO formation and reduction rates were similar between the two blending methods, likely due to comparable global equivalence ratios.
{"title":"Numerical investigation of combustion behaviors and NOx emissions in a 20 % ammonia co-firing tangential fired boiler: Synergistic effects of blending method and injection location","authors":"Yawei Song , Qifu Lin , Sheng Su , Longwei Chen , Chengzhou Liu , Weiye Chen , Zhenyang Li , Yiman Jiang , Dianwu Wu , Hansheng Feng , Yangjiong Liu , Guangnan Luo , Jun Xiang","doi":"10.1016/j.joei.2025.102406","DOIUrl":"10.1016/j.joei.2025.102406","url":null,"abstract":"<div><div>Ammonia injection location and ammonia-coal blending method significantly affect boiler combustion performance and pollutant emissions, yet their synergistic effects remain unclear. To investigate this synergistic effect, six cases of 20 % ammonia co-firing with coal were simulated in a 330 MW tangentially fired boiler, including pure coal and ammonia-coal co-injection through four-layer burners, as well as in-burner and in-boiler blending using burners at two different heights. The temperature distribution, coal burnout behaviors, and NO<sub>x</sub> generation characteristics were obtained. The results showed that the ammonia injection location and fuel blending method jointly influence the high-temperature distribution in the main combustion zone. With upper ammonia injection, the in-burner blending shifts the high-temperature zone to the upper of main combustion zone and its downstream regions, whereas in-boiler blending confines it to the bottom. However, bottom injection exhibits the opposite trend. These higher-temperature areas corresponded to increased concentrations of H<sub>2</sub>O and CO<sub>2</sub>, enhancing thermal radiation and heat transfer. Ammonia injection through either the upper or bottom burner using the in-boiler blending method increased the peak coal burnout rate and narrowed the half-peak width in the main combustion zone. However, compared with upper injection, bottom ammonia injection shifted the burnout peak toward the reduction zone, likely due to lower temperatures from pure ammonia combustion that hinder coal ignition. Although the NO concentrations were comparable between the two fuel blending methods regardless of injection location, the NO formation and reduction rates varied with combination of injection position and blending method. Specifically, with bottom ammonia injection, in-boiler blending yielded a higher NO reduction rate by NH<sub>3</sub>, while in-burner blending led to greater fuel-NO formation. For upper injection, however, the NO formation and reduction rates were similar between the two blending methods, likely due to comparable global equivalence ratios.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102406"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733341","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}
Formic acid dehydrogenation is a promising method for clean hydrogen production. However, its economic feasibility is largely limited by catalyst selectivity and cost. In this study, biomass-derived carbon supported Ni–Co alloy catalysts were synthesized via an in-situ pyrolysis strategy using soybean as a renewable carbon source. Various characterization results confirmed the homogeneous dispersion of Ni–Co alloy nanoparticles within the carbon matrix and revealed that the intimate contact between Ni and Co created abundant interfacial sites, where the incorporation of Co effectively modified the binding energy of Ni, promoted hydrogen release, and simultaneously suppressed CO formation, thereby accelerating the dehydrogenation reaction. In addition to alloy formation, the Ni/Co ratio also regulated the evolution of K species on the carbon surface, thereby influencing the generation of basic sites. These basic sites subsequently enhanced formic acid adsorption and facilitated its initial decomposition through strengthened interactions with formate intermediates. On this basis, the synergistic Ni–Co alloy structure further strengthened electronic interactions with intermediates and stabilized the active phase at high temperatures, thereby facilitating the dehydrogenation pathway. Benefiting from these combined effects, the optimized Ni0.2Co0.8–Soy catalyst delivered excellent activity with CO2 selectivity up to 98 % and a turnover frequency (TOF) of 0.069 s−1 at 523 K, while maintaining remarkable durability over ten consecutive cycles. This work highlights the dual contribution of endogenous heteroatoms and the cooperative functionality of the Ni–Co alloy, providing new insights into the design of efficient and sustainable non-noble metal systems for hydrogen production.
{"title":"Synergistic effect of intrinsic heteroatoms and Ni–Co alloy in biomass-derived carbon catalysts for efficient formic acid dehydrogenation","authors":"Xiucong Wang, Yuchun Zhang, Peng Fu, Haoran An, Zhiyu Li, Chunyan Tian","doi":"10.1016/j.joei.2025.102417","DOIUrl":"10.1016/j.joei.2025.102417","url":null,"abstract":"<div><div>Formic acid dehydrogenation is a promising method for clean hydrogen production. However, its economic feasibility is largely limited by catalyst selectivity and cost. In this study, biomass-derived carbon supported Ni–Co alloy catalysts were synthesized via an in-situ pyrolysis strategy using soybean as a renewable carbon source. Various characterization results confirmed the homogeneous dispersion of Ni–Co alloy nanoparticles within the carbon matrix and revealed that the intimate contact between Ni and Co created abundant interfacial sites, where the incorporation of Co effectively modified the binding energy of Ni, promoted hydrogen release, and simultaneously suppressed CO formation, thereby accelerating the dehydrogenation reaction. In addition to alloy formation, the Ni/Co ratio also regulated the evolution of K species on the carbon surface, thereby influencing the generation of basic sites. These basic sites subsequently enhanced formic acid adsorption and facilitated its initial decomposition through strengthened interactions with formate intermediates. On this basis, the synergistic Ni–Co alloy structure further strengthened electronic interactions with intermediates and stabilized the active phase at high temperatures, thereby facilitating the dehydrogenation pathway. Benefiting from these combined effects, the optimized Ni<sub>0</sub>.<sub>2</sub>Co<sub>0</sub>.<sub>8</sub>–Soy catalyst delivered excellent activity with CO<sub>2</sub> selectivity up to 98 % and a turnover frequency (TOF) of 0.069 s<sup>−1</sup> at 523 K, while maintaining remarkable durability over ten consecutive cycles. This work highlights the dual contribution of endogenous heteroatoms and the cooperative functionality of the Ni–Co alloy, providing new insights into the design of efficient and sustainable non-noble metal systems for hydrogen production.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102417"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733344","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 : 2025-12-09DOI: 10.1016/j.joei.2025.102412
Shuai Liu , Yanhui Liu , Ruina Li , Guangju Xu , Xinchang Zhu , Xiaona Yan
A small amount of lubricating oil additives are involved in combustion and undergo reactions during the operation of a diesel engine. The elements such as Mg, Ca, and Zn contained in them will oxidize to form metallic ash, thereby affecting the oxidation properties of particulate matter. To study the influence of metallic ash on the oxidation activity of particulate matter, lubricating oil additives with different blending ratios were used for tests and the generated particulate matter was collected. The physical and chemical properties of particulate matter were studied and analyzed by using scanning electron microscopy, Fourier transform infrared spectroscopy and other instruments. Based on the molecular dynamics simulation method, the research and analysis further reveal the influence mechanism of ash content on the oxidation of particulate matter. Research shows that with the blending of lubricating oil additives, all lubricating oil additives have increased the oxidation activity of particulate matter, shortened the oxidation time and reduced the initial oxidation temperature. At the molecular level, there is an adsorption trend with electron transfer between metallic ash and particulate matter. The specific order of the oxidation effect on particulate matter is MoO3 > CaSO4 > MgSO4≈Zn3(PO4)2.
{"title":"Research on the influence of lubricating oil derived ash on the oxidation characteristics of diesel engine particulate matter","authors":"Shuai Liu , Yanhui Liu , Ruina Li , Guangju Xu , Xinchang Zhu , Xiaona Yan","doi":"10.1016/j.joei.2025.102412","DOIUrl":"10.1016/j.joei.2025.102412","url":null,"abstract":"<div><div>A small amount of lubricating oil additives are involved in combustion and undergo reactions during the operation of a diesel engine. The elements such as Mg, Ca, and Zn contained in them will oxidize to form metallic ash, thereby affecting the oxidation properties of particulate matter. To study the influence of metallic ash on the oxidation activity of particulate matter, lubricating oil additives with different blending ratios were used for tests and the generated particulate matter was collected. The physical and chemical properties of particulate matter were studied and analyzed by using scanning electron microscopy, Fourier transform infrared spectroscopy and other instruments. Based on the molecular dynamics simulation method, the research and analysis further reveal the influence mechanism of ash content on the oxidation of particulate matter. Research shows that with the blending of lubricating oil additives, all lubricating oil additives have increased the oxidation activity of particulate matter, shortened the oxidation time and reduced the initial oxidation temperature. At the molecular level, there is an adsorption trend with electron transfer between metallic ash and particulate matter. The specific order of the oxidation effect on particulate matter is MoO<sub>3</sub> > CaSO<sub>4</sub> > MgSO<sub>4</sub>≈Zn<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102412"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733433","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 : 2025-12-09DOI: 10.1016/j.joei.2025.102413
Hu Chen, Tilun Shan, Sicheng Liu, Ting Liu, Huawei Zhang
The continuous accumulation of waste plastics and chromium-containing slag (CCS) poses a significant threat to the ecological environment, making the development of efficient co-processing technologies extremely urgent. This study innovatively proposes a co-pyrolysis strategy for plastics and CCS to achieve simultaneous resource recovery and detoxification. CCS, rich in metal oxides such as MgO, Fe2O3/Al2O3, serves as an efficient catalyst for plastic pyrolysis. Experimental results demonstrate that the introduction of CCS significantly enhances plastic pyrolysis efficiency: the gas yield increased by up to 12.44 wt%, the oil yield by up to 3.51 wt%, while significantly reducing the reaction activation energy and lowering the characteristic pyrolysis temperature by a maximum of 27 °C. Py-GC/MS and GC analyses further revealed that CCS directs the pyrolysis products toward a lower carbon number distribution, with light oil content increasing by 18.68 % and olefin yield rising by over 9.17 %. Conversely, the highly toxic and strongly oxidizing Cr (VI) present in CCS was effectively reduced during co-pyrolysis. EPA 3060a tests showed that the reduction rates of Cr (VI) by LDPE, HDPE, PP, PS, PVC, and PET reached 71.79 %, 59.61 %, 48.56 %, 74.29 %, 82.86 %, and 77.15 %, respectively. Notably, PVC contains chlorine elements, while PET contains oxygen elements, both can provide a stronger reducing environment, so they have better detoxification performance. Based on TG-FTIR functional group analysis, this study elucidates the synergistic mechanism involved in the co-pyrolysis process, demonstrating the feasibility and potential of this “waste-treats-waste” strategy for synergistic detoxification.
{"title":"The effect of plastic type on the product distribution and Cr (VI) removal in the co-pyrolysis of plastics and chromium-containing slag","authors":"Hu Chen, Tilun Shan, Sicheng Liu, Ting Liu, Huawei Zhang","doi":"10.1016/j.joei.2025.102413","DOIUrl":"10.1016/j.joei.2025.102413","url":null,"abstract":"<div><div>The continuous accumulation of waste plastics and chromium-containing slag (CCS) poses a significant threat to the ecological environment, making the development of efficient co-processing technologies extremely urgent. This study innovatively proposes a co-pyrolysis strategy for plastics and CCS to achieve simultaneous resource recovery and detoxification. CCS, rich in metal oxides such as MgO, Fe<sub>2</sub>O<sub>3</sub>/Al<sub>2</sub>O<sub>3</sub>, serves as an efficient catalyst for plastic pyrolysis. Experimental results demonstrate that the introduction of CCS significantly enhances plastic pyrolysis efficiency: the gas yield increased by up to 12.44 wt%, the oil yield by up to 3.51 wt%, while significantly reducing the reaction activation energy and lowering the characteristic pyrolysis temperature by a maximum of 27 °C. Py-GC/MS and GC analyses further revealed that CCS directs the pyrolysis products toward a lower carbon number distribution, with light oil content increasing by 18.68 % and olefin yield rising by over 9.17 %. Conversely, the highly toxic and strongly oxidizing Cr (VI) present in CCS was effectively reduced during co-pyrolysis. EPA 3060a tests showed that the reduction rates of Cr (VI) by LDPE, HDPE, PP, PS, PVC, and PET reached 71.79 %, 59.61 %, 48.56 %, 74.29 %, 82.86 %, and 77.15 %, respectively. Notably, PVC contains chlorine elements, while PET contains oxygen elements, both can provide a stronger reducing environment, so they have better detoxification performance. Based on TG-FTIR functional group analysis, this study elucidates the synergistic mechanism involved in the co-pyrolysis process, demonstrating the feasibility and potential of this “waste-treats-waste” strategy for synergistic detoxification.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102413"},"PeriodicalIF":6.2,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733350","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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