Journal of The Energy Institute最新文献

{"title":"Experimental study on pollutant emissions and fly ash characteristics in ammonia-bituminous coal co-firing under different ammonia injection modes in a swirl burner","authors":"Jingwen Liu ,&nbsp;Qiwei Wu ,&nbsp;Kunquan He ,&nbsp;Xiao Kang ,&nbsp;Xiaobei Shi ,&nbsp;Hao Zhou","doi":"10.1016/j.joei.2025.102265","DOIUrl":"10.1016/j.joei.2025.102265","url":null,"abstract":"<div><div>This study investigates ammonia-bituminous coal co-firing using a 200 kW down-fired combustion system, examining three ammonia co-firing methods—premixed (PM) and staged modes (SM(A)/SM(B))—at 0–30 % ratios. The research systematically analyzes their effects on combustion characteristics, flue gas emissions, and fly ash properties within a swirl burner configuration. The results demonstrate that the premixed ammonia injection method exhibits minimal impact on flame temperature distribution, while staged ammonia injection shifts the peak temperature location downward within the flame structure. CO/CO₂ decreased after ammonia co-firing due to the carbon-free property of ammonia. NO_x generation exhibited mode-dependent behavior: under PM mode, it followed an initial increase then a decreasing trend, recovering to pure coal levels at 30 % ammonia blending ratio. SM(A) mode achieved minimum NO_x at a 20 % co-firing ratio, while SM(B) mode showed a monotonic rise with increasing ammonia fraction. Under PM mode operation at 10 % ammonia co-firing, the NO_x was reduced by 63.3 % when the OFA ratio was increased from 10 % to 30 %, which verified the effectiveness of the hierarchically optimized ammonia-coal co-firing process for NO_x control. After ammonia co-firing, the unburned carbon content of fly ash was reduced, the average particle size Dv₅₀ decreased, the proportion of 2–10 μm fine particles increased, ammonia doping promoted the generation of spherical Al/Si/Fe oxides, and the porous flocculent decreased. This study provides a key design basis for the efficient and clean combustion of ammonia-coal in swirl burners.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102265"},"PeriodicalIF":6.2,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competition mechanism between Na release and Hg form evolution in high-temperature gasification condition revealed from bond distribution of coal slag","authors":"Ziying Li ,&nbsp;Keke Zhao ,&nbsp;Caixia Yue ,&nbsp;Chong He ,&nbsp;Ping Li ,&nbsp;Xingjun Wang ,&nbsp;Longfei Gao ,&nbsp;Liping Chang ,&nbsp;Weiren Bao ,&nbsp;Jiancheng Wang","doi":"10.1016/j.joei.2025.102269","DOIUrl":"10.1016/j.joei.2025.102269","url":null,"abstract":"<div><div>The entrained-flow coal gasification is a key technology to realize to the largescale and high-efficient utilization of coal in China. The Hg in the coal is readily released to the gas phase at high temperature, posing significant risks to human health and the environment. However, the evolution of the gaseous Hg in the entrained-flow coal gasification condition is scarcely investigated due to its extremely high operation temperature (&gt;1500 °C) which failed the experimental characterization. Further, some alkali elements in coal slag are readily released to the gas phase, possibly influencing the Hg evolution mechanism. The relationship between these two processes remains unknown. In this study, the evolution behavior of the trace gaseous Hg in an entrained-flow coal gasifier was revealed by thermodynamic modelling. Results demonstrated that the HgCl (g) is the relatively thermodynamically stable form in the entrained-flow coal gasifer compared to the HgCl₂(g). The high water vapor content in the Texaco gasifier favored HgO (g) formation. The increases of the Cl content and H₂S content advantaged the generation of HgCl (g) or HgCl₂(g) and HgS (g), respectively. Further, the evolution mechanism of HgCl(g) was influenced by the Na release which is intrinsically determined by the slag structure. The increasing Na₂O content or the decreasing the SiO₂ content of coal ash improved the formation of the structure units Si-O-Al and Si-O-NaAl, inhibiting the Na release. Due to its stronger affinity for gaseous Cl compared to Na, Hg exhibits enhanced formation of both HgCl(g) and HgCl₂ (g) under such conditions. The findings of this study provided the theoretical guide for the adjuring the trace Hg evolution behavior based on the gasification parameter and the coal ash composition.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102269"},"PeriodicalIF":6.2,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144918102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of diesel components on ignition and combustion characteristics of the diesel engine under different oxygen concentrations","authors":"Sai Wang,&nbsp;Xinsheng Jiang,&nbsp;Yunxiong Cai,&nbsp;Dongliang Zhou,&nbsp;Keyu Lin,&nbsp;Run Li","doi":"10.1016/j.joei.2025.102268","DOIUrl":"10.1016/j.joei.2025.102268","url":null,"abstract":"<div><div>The plateau environment would cause a series of problems, such as difficult cold start, incomplete combustion, decreased thermal efficiency and insufficient power. Although many methods have been used to solve these problems, the most critical is to start from the fuel itself, there is a necessity to investigate the design of diesel fuel composition in high altitude and oxygen-deficient environment. Therefore, this study aims to reveal the effects of different diesel components on the ignition and combustion characteristics at low oxygen concentration, and to provide a theoretical basis on fuel design strategy. An optimized DPCS model was used to develop a six-component diesel surrogate capable of reproducing the physicochemical properties of diesel fuels. Then, the KIVA-3V code coupled with CHEMKIN was established to model the ignition and combustion process and verified with the experimental results. Furthermore, the effects of different diesel components of the diesel surrogate on ignition and combustion behaviors were investigated. The results indicated that the incomplete combustion loss increased at low oxygen concentration, and the effect on IMEP was dominant. In addition, at low oxygen concentration, CA10 was delayed and affected the combustion efficiency more significantly, the combustion duration was prolonged, and the pressure rise rate was nearly linear with CA10. In addition, HMN and n-hexadecane were the predominate components affecting CA10, combustion duration, pressure rise rate and IMEP, thus it was particularly critical to adjust the proportion of these two components when designing the fuel.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102268"},"PeriodicalIF":6.2,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced steam gasification of lignin to generate H2-enriched syngas over a (Ni-Ce)/CaO catalyst","authors":"Wenzhe Zhang ,&nbsp;Shanshan Dai ,&nbsp;Yong Liu ,&nbsp;Jie Li ,&nbsp;Guozhang Chang ,&nbsp;Cuiping Wang ,&nbsp;Jian Zhang","doi":"10.1016/j.joei.2025.102264","DOIUrl":"10.1016/j.joei.2025.102264","url":null,"abstract":"<div><div>The utilization of industrially generated lignin is an important aspect of achieving worldwide carbon neutrality. In this study, Ni/CaO, Ce/CaO and (Ni-Ce)/CaO catalysts were prepared using an impregnation method to improve the production of H₂-enriched syngas from lignin steam gasification. Results show that the Ni/CaO and Ce/CaO exhibited different effects when applied to steam gasification, the former improved the conversion of solid lignin whereas the latter promoted decomposition of the resulting volatiles. The (Ni-Ce)/CaO catalyst provided a remarkable synergistic effect on production of H₂-enriched syngas. The mass-based yield of gaseous products and the volume-based proportion of H₂ in these products were respectively 70.8 % and 61.1 % in the presence of the (Ni-Ce)/CaO catalyst with a Ni-to-Ce molar ratio of 1:0.9. The H₂ yields obtained from this material were found to gradually decrease from 763 to 681 mL/(g lignin) during five repeated uses. This gradual deactivation of the (Ni-Ce)/CaO catalyst was ascribed to both carbon deposition and the formation of CaSO₄ by reactions between sulfur in the lignin ash and the CaO component.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102264"},"PeriodicalIF":6.2,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the interaction mechanism of components in bio-oil catalytic reforming for hydrogen production","authors":"Tingting Liu,&nbsp;Andong Zhang,&nbsp;Zhihe Li,&nbsp;Mingze Gao,&nbsp;Shengqi Wang,&nbsp;Ning Li,&nbsp;Shaoqing Wang,&nbsp;Tianhao Li","doi":"10.1016/j.joei.2025.102266","DOIUrl":"10.1016/j.joei.2025.102266","url":null,"abstract":"<div><div>To elucidate the complex reaction mechanism of hydrogen production by catalytic reforming of bio-oil and reveal the interactions between the various components, this study selected four minimal model compounds (formic acid, methanol, acetone, and phenol) as typical representatives of acids, alcohols, ketones, and phenols, respectively, to avoid interference from multiple functional groups. Experiments were conducted using an in-situ gasification fixed-bed reactor (800 °C, WCR = 15, Ni/Al₂O₃ catalyst). The results show that methanol exhibits the best hydrogen production performance due to its high H/C ratio (4:1) and [-OH] with 75 mol% H₂ concentration and &gt;97 % selectivity. When blended with formic acid, acetone, or phenol, methanol's hydrogen yield increased by 25 %, 8 %, 8 %, respectively. Formic acid-acetone mixtures enhanced H₂ concentration. However, [-C=O] promoted carbon chain elongation, resulting in fibrous carbon deposition and accelerated catalyst deactivation. Despite the presence of [-OH] in phenol, the stability of its aromatic ring structure limited reforming efficiency, yielding H₂ concentrations of 60–64 mol%. TG-DTG, SEM and FTIR analyses revealed that fibrous carbon deposition was predominantly driven by [-C=O], whereas [-OH] effectively suppressed carbon growth. This study elucidates the mechanistic role of bio-oil component interactions in hydrogen production, providing a theoretical foundation for optimizing catalyst design and feedstock formulations to advance sustainable hydrogen production from bio-oil.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102266"},"PeriodicalIF":6.2,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive evaluation of kinetic reaction mechanisms for NO and N2O emissions during NH3/H2 combustion across multi-temperature regimes","authors":"Shangkun Quan ,&nbsp;Jiakun Mei ,&nbsp;Dongfang Li ,&nbsp;Yulian Huang ,&nbsp;Zhouhang Li ,&nbsp;Xing Zhu ,&nbsp;Hua Wang ,&nbsp;Xi Yang ,&nbsp;Mingyu Zhang ,&nbsp;Ryang-Gyoon Kim","doi":"10.1016/j.joei.2025.102260","DOIUrl":"10.1016/j.joei.2025.102260","url":null,"abstract":"<div><div>Ammonia is an alternative green fuel to achieve carbon neutrality. However, the emissions of N₂O and NO_x are the major challenges for broad applications. Understanding N₂O and NO_x formation and reduction at various temperatures is crucial for developing ammonia combustion technologies in equipment across multi-temperature regimes. This study comprehensively investigates the performance of 12 kinetic reaction mechanisms in predicting N₂O and NO emissions at various temperatures. A significant variation is observed among different kinetic reaction mechanisms in the prediction of N₂O and NO emissions across temperatures. The kinetic reaction mechanisms proposed by Zhang, Nakamura and Okafor exhibit the highest predictive accuracy at low, medium and high temperatures, respectively. Based on sensitivity analysis, under all conditions and kinetic reaction mechanisms, the reaction H + O₂&lt;=&gt;O + OH consistently exhibits high positive sensitivity coefficients for the mole fractions of N₂O and NO. Meanwhile, the reactions N₂O + H&lt;=&gt;N₂+OH and NH₂+NO&lt;=&gt;N₂+H₂O exhibit large negative sensitivity coefficients for the mole fractions of N₂O and NO, respectively. In addition, N₂O and NO are primarily produced by NO and HNO via the reactions NH + NO&lt;=&gt;N₂O + H and HNO + OH&lt;=&gt;NO + H₂O, HNO + O₂&lt;=&gt;NO + HO₂, respectively, while N₂O is primarily consumed via reactions with O and H radicals. Notably, the radicals NH and NH₂ play critical roles in the emissions of N₂O and NO. Furthermore, the sensitivity coefficients of key reactions vary significantly across different kinetic reaction mechanisms, highlighting the need for further investigation. This study provides valuable insights and a foundation for future development and refinement of ammonia combustion kinetic mechanisms.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102260"},"PeriodicalIF":6.2,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing syngas production from biogas: Combined steam and CO2 reforming over mechanochemically synthesized Ru/CeO2-Al2O3 catalysts","authors":"Jingyu Fu ,&nbsp;Yanrui Si ,&nbsp;Wei Huang ,&nbsp;Zhichao Zhao ,&nbsp;Zetao Huang ,&nbsp;Cai Zeng ,&nbsp;Xueqi Lian ,&nbsp;Zuhao Li","doi":"10.1016/j.joei.2025.102261","DOIUrl":"10.1016/j.joei.2025.102261","url":null,"abstract":"<div><div>Bi-reforming of biogas offers a sustainable pathway for producing syngas, a crucial precursor for fuels and chemicals. In this work, we demonstrate the efficacy of a scalable and environmentally friendly mechanochemical approach to synthesize Ru catalysts supported on CeO₂-Al₂O₃ mixed oxides. The catalysts' performance was evaluated in a fixed-bed reactor at 800 °C using a model biogas feed. Among the prepared catalysts, the 0.5Ru/CeO₂-Al₂O₃ variant demonstrated outstanding catalytic performance, achieving an initial CH₄ conversion of approximately 86 % and maintaining remarkable stability over 100 h of continuous operation. A comprehensive characterization campaign, including XRD, H₂-TPR, XPS, SEM, and HRTEM revealed that the mechanochemical synthesis promoted a strong metal-support interaction. This was evidenced by the formation of well-dispersed Ru nanoparticles in close contact with the support, leading to an increased concentration of Ce³⁺ species and enhanced catalyst reducibility. These properties are critical for facilitating the gasification of carbon deposits, thereby mitigating deactivation. Post-reaction analysis confirmed that coking was the primary cause of deactivation, with the more stable 0.5Ru catalyst showing a greater resistance to the formation of graphitic carbon. This research demonstrates the efficacy of the mechanochemically prepared Ru/CeO₂-Al₂O₃ catalysts for biogas bi-reforming and highlights carbon deposition as a critical challenge, underscoring the need for mitigation strategies to prolong catalyst performance.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102261"},"PeriodicalIF":6.2,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of the generation technology, combustion modulation and reaction mechanism of O2(a1Δg) non-thermal plasma","authors":"Qing Wang ,&nbsp;Yan Pan ,&nbsp;Xinmin Wang ,&nbsp;Huaiyu Zhou ,&nbsp;Shuang Wu ,&nbsp;Zhongyuan Hu ,&nbsp;Chunxia Jia ,&nbsp;Da Cui ,&nbsp;Jingru Bai ,&nbsp;Shuo Pan","doi":"10.1016/j.joei.2025.102256","DOIUrl":"10.1016/j.joei.2025.102256","url":null,"abstract":"<div><div>Singlet oxygen (O₂(a¹Δg)), the first electronically excited singlet state of molecular oxygen, exhibits high reactivity due to its unique electron spin configuration. Its ability to introduce high-energy electron states into fuel combustion reactions makes it a promising technology in combustion science. In this paper, the research progress of O₂(a¹Δg) combustion assisted technology is comprehensively reviewed. Firstly, the basic physicochemical properties of O₂(a¹Δg) and the respective advantages and disadvantages of various excitation device production and detection methods are introduced. Then, the impact of how O₂(a¹Δg) affects the optimisation of various parameters of ignition and combustion assistance during the combustion process is highlighted. The kinetic mechanisms and molecular simulation studies of the involvement of O₂(a¹Δg) in chain reactions and chain initiation are investigated. Finally, gaps in O₂(a¹Δg) fuelled combustion are presented to provide ideas for the direction of future efforts in research. Although the concentration and stability of O₂(a¹Δg) are potentially risky, it can be effectively controlled by improving the coupling of novel combustion devices adapted to O₂(a¹Δg) with new technologies and researching new chemical catalysts. Therefore, O₂(a¹Δg)-assisted combustion is a key technology for solving combustion problems in the future. Using O₂(a¹Δg) as a novel oxidant for combustion, further catalytic combustion assisting and new reaction pathways are formed to solve the problems of ignition, steady combustion and burnout of fuels, with a view to wider technological applications, maturation and expansion of O₂(a¹Δg) in the future in the field of promoting the combustion science of different fuels.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102256"},"PeriodicalIF":6.2,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145018515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing catalytic activity and sulfur resistance of Fe- or Ce-modified Cu-SSZ-13 catalysts for NH3-SCR in diesel exhaust system","authors":"Junheng Liu ,&nbsp;Shengyue Xiong ,&nbsp;Jianyu Du ,&nbsp;Zhancheng Dou ,&nbsp;Feng Chen ,&nbsp;Chengcheng Ao ,&nbsp;Qian Ji","doi":"10.1016/j.joei.2025.102262","DOIUrl":"10.1016/j.joei.2025.102262","url":null,"abstract":"<div><div>The Cu-SSZ-13 zeolite catalyst was synthesized via ion-exchange method, followed by Fe or Ce incorporation to improve catalytic activity and sulfur resistance for NH₃-SCR. The synthesized catalysts were evaluated by the tests of NH₃-SCR activity before and after sulfur poisoning process, along with various characterizations, including XRD, ICP-OES, BET, XPS, H₂-TPR and <em>in</em>-<em>situ</em> DRIFTS. The results demonstrate that the modified catalysts exhibit a broadened operation temperature window and superior sulfur resistance compared to Cu-SSZ-13, especially Fe-modified catalyst. The introduction of Fe or Ce can reduce the structural stability of Cu-SSZ-13 catalyst, which leads to the substitution of some weakly adsorbed Cu²⁺ ions with Fe or Ce ions in the CHA framework. The charge transfer between Fe/Ce and Cu ions effectively enhances the redox performance of the catalyst, but the partial substitution of Cu²⁺ ions in the 8 MR of Cu-SSZ-13 catalyst with Fe or Ce ions results in a slight decline in low-temperature activity. The incorporation of Fe mitigates sulfur poisoning on Cu active sites by modifying the composition of sulfate species, thereby improving the sulfur resistance of the Fe-modified catalyst. Ce modification promotes Cu⁺ reduction at lower temperatures, enhancing high-temperature activity. Compared with Fe/Cu-F, the content of Cu ions in Ce/Cu-F is 11.9 % higher, indicating Ce/Cu-F contains more active Cu. In addition, <em>in</em>-<em>situ</em> DRIFTS shows that the prepared Fe/Cu-SSZ-13 follows mechanisms of Eley-Rideal to undergo NH₃-SCR reaction. In the Fe-modified catalyst system, synergetic Cu-Fe dual active sites are identified to enhance surface Lewis acidity, while Cu sites exhibit higher activity.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102262"},"PeriodicalIF":6.2,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relations between MILD combustion and LTC strategies in diluted compression ignition conditions","authors":"Michał T. Lewandowski ,&nbsp;Zhongye Xue ,&nbsp;Corinna Schulze-Netzer ,&nbsp;Terese Løvås","doi":"10.1016/j.joei.2025.102206","DOIUrl":"10.1016/j.joei.2025.102206","url":null,"abstract":"<div><div>This study investigates the applicability of the classical Moderate and Intense Low Oxygen Dilution (MILD) combustion definition to identify combustion regimes under high-pressure conditions relevant to compression ignition (CI) engines. Using <em>n</em>-heptane as a diesel surrogate fuel, a novel methodology has been developed that combines an experimental campaign, Stochastic Reactor Model (SRM) simulations, and well-stirred reactor (WSR) modeling to analyze Low-Temperature Combustion (LTC) strategies under both idealized and engine-relevant conditions. Initially, WSR simulations with detailed chemistry were used to generate <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>in</mi></mrow></msub><mo>−</mo><msub><mrow><mi>X</mi></mrow><mrow><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msub></mrow></math></span> maps, analyzing the effects of pressure, dilution, and equivalence ratio on combustion regimes. The results show that elevated pressure lowers self-ignition temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>si</mi></mrow></msub></math></span>), while increased dilution and lean mixtures promote flattening of the S-curve, facilitating the transition to the MILD regime. However, satisfying the MILD criterion <span><math><mrow><mi>Δ</mi><mi>T</mi><mo>&lt;</mo><msub><mrow><mi>T</mi></mrow><mrow><mi>si</mi></mrow></msub></mrow></math></span> becomes increasingly difficult under high-pressure conditions, requiring higher levels of dilution and inlet temperature. Low-temperature oxidation (LTO) was found to enhance pre-ignition behavior when <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>si</mi></mrow></msub></math></span> exceeded approximately 525 K, with a more pronounced effect at elevated pressures. The SRM, calibrated against CFD-supported experimental data of the PCCI regime, was then used to replicate realistic in-cylinder conditions of both PCCI and HCCI, and to refine WSR input parameters. The comparative analysis revealed that HCCI enables LTC at lower oxygen dilution levels compared to PCCI, emphasizing the importance of mixture homogeneity and pre-ignition chemistry. The observed reduction in <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>WSR</mi></mrow></msub></math></span> at high pressures across varying oxygen concentrations is consistent with the primary goal of LTC strategies-minimizing NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> emissions. Overall, this work demonstrates the limitations of idealized homogeneous reactors in identifying MILD regimes under realistic conditions and highlights the value of incorporating advanced yet computationally feasible reactor models, such as SRM, for regime mapping and emissions analysis in practical engine applications.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"123 ","pages":"Article 102206"},"PeriodicalIF":6.2,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893538","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}