Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133667
Mingjun Chen , Xueni Chen , Yili Kang , Zheng Cheng , Lijun You , Gang Xiong , Dongsheng Yang , Chaozhong Qin
A normal-pressure shale gas reservoir generally exhibits a low formation pressure coefficient, making fracturing fluid flow-back difficult and leading to severe water blocking. Formation heat treatment (FHT) can effectively remove water and induce new fractures to prevent such formation damage and increase shale permeability. However, the range of the heat treatment in shale gas reservoir remains unclear, as does its effectiveness in mitigating water blocking. Laboratory experiments and numerical simulation are conducted in this paper. The experimental results indicate that shale permeability is significantly improved by FHT. A mathematical model coupling heat transfer and shale permeability is established, considering the initial reservoir permeability and heat treatment time. The heat transfer range around a shale gas well after injection of 800℃ gas at a pressure difference of 5 MPa is simulated. The results indicate that (1) the heat transfer range can extend over 1.0 m within a heat treatment time longer than 48 h for a shale formation with the permeability more than 0.1mD after hydraulic fracturing; (2) a one order of magnitude increase in permeability enhances the heat transfer range by 40 %-100 %; (3) with each 24 h increase in heat treatment time, the heat transfer range expands by 27 %- 40 %; (4) the primary factors controlling the heat transfer range are initial reservoir permeability and heat treatment time; (5) an autocatalytic effect in actual FHT suggests the treatment range may exceed simulation estimates. This study illuminates the stimulation effect of FHT technology, which is beneficial for further understanding the increase of productivity of a normal-pressure shale gas well.
{"title":"Investigation of water blocking mitigation in a normal-pressure shale gas reservoir by high-temperature treatment: Insights from heat transfer range","authors":"Mingjun Chen , Xueni Chen , Yili Kang , Zheng Cheng , Lijun You , Gang Xiong , Dongsheng Yang , Chaozhong Qin","doi":"10.1016/j.fuel.2024.133667","DOIUrl":"10.1016/j.fuel.2024.133667","url":null,"abstract":"<div><div>A normal-pressure shale gas reservoir generally exhibits a low formation pressure coefficient, making fracturing fluid flow-back difficult and leading to severe water blocking. Formation heat treatment (FHT) can effectively remove water and induce new fractures to prevent such formation damage and increase shale permeability. However, the range of the heat treatment in shale gas reservoir remains unclear, as does its effectiveness in mitigating water blocking. Laboratory experiments and numerical simulation are conducted in this paper. The experimental results indicate that shale permeability is significantly improved by FHT. A mathematical model coupling heat transfer and shale permeability is established, considering the initial reservoir permeability and heat treatment time. The heat transfer range around a shale gas well after injection of 800℃ gas at a pressure difference of 5 MPa is simulated. The results indicate that (1) the heat transfer range can extend over 1.0 m within a heat treatment time longer than 48 h for a shale formation with the permeability more than 0.1mD after hydraulic fracturing; (2) a one order of magnitude increase in permeability enhances the heat transfer range by 40 %-100 %; (3) with each 24 h increase in heat treatment time, the heat transfer range expands by 27 %- 40 %; (4) the primary factors controlling the heat transfer range are initial reservoir permeability and heat treatment time; (5) an autocatalytic effect in actual FHT suggests the treatment range may exceed simulation estimates. This study illuminates the stimulation effect of FHT technology, which is beneficial for further understanding the increase of productivity of a normal-pressure shale gas well.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133667"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133294
Ziqi Zhao , Jirui Jin , Qian Du , Dun Li , Jianmin Gao , Heming Dong , Yu Zhang , Di Wu , Xiao Yang
Fossil fuels are wasteful, and they pollute the environment when utilized as energy sources. Soot from the incomplete combustion of fossil fuels has received considerable attention due to its harmful effects on the environment and the human body, and its utilization value in terms of materials. In this study, experiments on the pyrolysis of coal mixed with sodium carbonate (NaNO3) at different carbon dioxide (CO2) concentrations were conducted on a drop tube furnace. Experimental results were explained using density functional theory (DFT) calculation by constructing structural models of the oxidation of naphthalene with and without sodium (Na) involvement. The results showed that the average particle size of soot decreased from 29.7 nm to 21.44 nm with an increase in CO2 concentration before the addition of Na. After the addition of Na, particle size exhibited a tendency of decreasing and then increasing, indicating that CO2 exerted oxidizing and adducting effects on soot. In an atmosphere with a high concentration of CO2, Na promoted the adducting effect, and particle size increased to 34.86 nm. Moreover, the addition of Na significantly increased oxygen content on the surface of soot, indicating that the participation of Na enhanced the oxidation reaction of soot. The results of the DFT calculations also proved that Na facilitated the occurrence of oxidation reaction by decreasing the energy barrier required for oxidation reaction from 9.28 kcal/mol to −64.62 kcal/mol through the transfer of electrons and the formation of active centers.
化石燃料是一种浪费性能源，在用作能源时会对环境造成污染。化石燃料不完全燃烧产生的烟尘，由于其对环境和人体的危害，以及在材料方面的利用价值，受到了广泛关注。本研究在滴管炉上进行了不同二氧化碳（CO2）浓度下煤与碳酸钠（NaNO3）混合热解的实验。通过构建有钠（Na）参与和无钠（Na）参与的萘氧化结构模型，利用密度泛函理论（DFT）计算解释了实验结果。结果表明，在添加 Na 之前，随着二氧化碳浓度的增加，烟尘的平均粒径从 29.7 nm 减小到 21.44 nm。加入 Na 后，粒度呈现出先减小后增大的趋势，表明 CO2 对烟尘产生了氧化和加成效应。在高浓度 CO2 的大气中，Na 促进了加成效应，粒径增加到 34.86 nm。此外，Na 的加入明显增加了烟尘表面的氧含量，表明 Na 的参与增强了烟尘的氧化反应。DFT 计算的结果也证明，Na 通过电子转移和活性中心的形成，将氧化反应所需的能量势垒从 9.28 kcal/mol 降低到 -64.62 kcal/mol，从而促进了氧化反应的发生。
{"title":"The synergistic influence mechanism of the alkali metal sodium and CO2 on coal rapid pyrolysis soot: Experiments and DFT calculations","authors":"Ziqi Zhao , Jirui Jin , Qian Du , Dun Li , Jianmin Gao , Heming Dong , Yu Zhang , Di Wu , Xiao Yang","doi":"10.1016/j.fuel.2024.133294","DOIUrl":"10.1016/j.fuel.2024.133294","url":null,"abstract":"<div><div>Fossil fuels are wasteful, and they pollute the environment when utilized as energy sources. Soot from the incomplete combustion of fossil fuels has received considerable attention due to its harmful effects on the environment and the human body, and its utilization value in terms of materials. In this study, experiments on the pyrolysis of coal mixed with sodium carbonate (NaNO<sub>3</sub>) at different carbon dioxide (CO<sub>2</sub>) concentrations were conducted on a drop tube furnace. Experimental results were explained using density functional theory (DFT) calculation by constructing structural models of the oxidation of naphthalene with and without sodium (Na) involvement. The results showed that the average particle size of soot decreased from 29.7 nm to 21.44 nm with an increase in CO<sub>2</sub> concentration before the addition of Na. After the addition of Na, particle size exhibited a tendency of decreasing and then increasing, indicating that CO<sub>2</sub> exerted oxidizing and adducting effects on soot. In an atmosphere with a high concentration of CO<sub>2</sub>, Na promoted the adducting effect, and particle size increased to 34.86 nm. Moreover, the addition of Na significantly increased oxygen content on the surface of soot, indicating that the participation of Na enhanced the oxidation reaction of soot. The results of the DFT calculations also proved that Na facilitated the occurrence of oxidation reaction by decreasing the energy barrier required for oxidation reaction from 9.28 kcal/mol to −64.62 kcal/mol through the transfer of electrons and the formation of active centers.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133294"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133723
Pengjie Kong , Hewen Li , Rongyue Sun , Jian Sun
Calcium Looping (CaL) holds great promise for high-temperature CO2 capture in the post-combustion phase. In this work, impregnated layer solution combustion (ILSC) was employed to synthesize the highly efficient Al-stabilized CaO-based CO2 sorbents. A comparative investigation was conducted on the dry and wet ILSC modes with discarded cigarette butts as the impregnated layer. The research delved into the impact of precursor solution concentration on the micromorphology, porosity, and CO2 capture capacity of the synthesized Al-stabilized CaO-based sorbent, shedding light on the associated mechanisms. Research reveals that CaO-based sorbents made via the ILSC process with lower precursor solution concentrations (i.e., liquid-to-solid ratios of 3.0 and 3.75) outperform those made with higher concentrations (i.e., liquid-to-solid ratios of 1.0 and 1.5). Notably, the sorbent produced via the wet ILSC mode with a low concentration precursor solution at a liquid-to-solid ratio of 3.0 shows remarkable cyclic CO2 capture capabilities. It maintains a capture capacity of 0.383 g CO2/g calcined sorbent in the 17th cycle, which is 70.8 % of its initial capacity. The dilute precursor solution is capable of sustaining the initial fibrous integrity of cigarette butts, unlike its concentrated counterpart, which destroys the fiber structure. This solution also enhances the uniform dispersion of Ca and Al and suppresses the high-temperature agglomeration of CaO grains.
钙循环（CaL）在燃烧后阶段的高温二氧化碳捕集方面前景广阔。本研究采用浸渍层溶液燃烧（ILSC）技术合成了高效的铝稳定氧化钙基二氧化碳吸附剂。以废弃烟头为浸渍层，对干法和湿法 ILSC 模式进行了比较研究。研究深入探讨了前驱体溶液浓度对合成的铝稳定氧化钙基吸附剂的微观形貌、孔隙率和二氧化碳捕获能力的影响，并揭示了相关机理。研究发现，通过 ILSC 工艺制作的前驱体溶液浓度较低（即液固比为 3.0 和 3.75）的氧化钙基吸附剂优于浓度较高（即液固比为 1.0 和 1.5）的吸附剂。值得注意的是，在液固比为 3.0 的低浓度前驱体溶液中，通过湿法 ILSC 模式制得的吸附剂显示出卓越的二氧化碳循环捕获能力。在第 17 个循环中，它的捕集能力保持在 0.383 克 CO2/克煅烧吸附剂，是其初始捕集能力的 70.8%。稀释的前驱体溶液能够保持烟头最初的纤维完整性，而不像浓缩的前驱体溶液会破坏纤维结构。这种溶液还能提高 Ca 和 Al 的均匀分散性，抑制 CaO 晶粒的高温团聚。
{"title":"Inert stabilizer enhanced CaO sorbents for CO2 capture: Insights through impregnated layer solution combustion synthesis","authors":"Pengjie Kong , Hewen Li , Rongyue Sun , Jian Sun","doi":"10.1016/j.fuel.2024.133723","DOIUrl":"10.1016/j.fuel.2024.133723","url":null,"abstract":"<div><div>Calcium Looping (CaL) holds great promise for high-temperature CO<sub>2</sub> capture in the post-combustion phase. In this work, impregnated layer solution combustion (ILSC) was employed to synthesize the highly efficient Al-stabilized CaO-based CO<sub>2</sub> sorbents. A comparative investigation was conducted on the dry and wet ILSC modes with discarded cigarette butts as the impregnated layer. The research delved into the impact of precursor solution concentration on the micromorphology, porosity, and CO<sub>2</sub> capture capacity of the synthesized Al-stabilized CaO-based sorbent, shedding light on the associated mechanisms. Research reveals that CaO-based sorbents made via the ILSC process with lower precursor solution concentrations (i.e., liquid-to-solid ratios of 3.0 and 3.75) outperform those made with higher concentrations (i.e., liquid-to-solid ratios of 1.0 and 1.5). Notably, the sorbent produced via the wet ILSC mode with a low concentration precursor solution at a liquid-to-solid ratio of 3.0 shows remarkable cyclic CO<sub>2</sub> capture capabilities. It maintains a capture capacity of 0.383 g CO<sub>2</sub>/g calcined sorbent in the 17th cycle, which is 70.8 % of its initial capacity. The dilute precursor solution is capable of sustaining the initial fibrous integrity of cigarette butts, unlike its concentrated counterpart, which destroys the fiber structure. This solution also enhances the uniform dispersion of Ca and Al and suppresses the high-temperature agglomeration of CaO grains.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133723"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of efficient and environmentally-friendly catalysts for the catalytic conversion of carbon dioxide (CO2) has been extensively investigated over a prolonged period. In this work, we successfully performed a cycloaddition reaction between CO2 and epoxides using metal- and halogen-free Lewis pairs as catalysts. Mechanistic investigations have revealed that Lewis acid-base pairs (LPs), a combination of Lewis acids (LAs) and Lewis bases (LBs), act in concert to activate epoxide and CO2, resulting in the efficient synthesis of various cyclic carbonates with high yields. Various epoxides are converted into cyclic carbonates with yields as high as 99% under cocatalyst-free and solvent-free conditions. Moreover, this homogeneous Lewis pair was incorporated into hypercrosslinked polymers through the Friedel-Crafts reaction, enabling the convenient recovery and reuse of the catalysts.
{"title":"Conversion of CO2 to cyclic carbonates using metal- and halogen-free Lewis pairs","authors":"Jialong Ou, Ziyang Xu, Quanlan Liao, Tianxiang Zhao","doi":"10.1016/j.fuel.2024.133651","DOIUrl":"10.1016/j.fuel.2024.133651","url":null,"abstract":"<div><div>The development of efficient and environmentally-friendly catalysts for the catalytic conversion of carbon dioxide (CO<sub>2</sub>) has been extensively investigated over a prolonged period. In this work, we successfully performed a cycloaddition reaction between CO<sub>2</sub> and epoxides using metal- and halogen-free Lewis pairs as catalysts. Mechanistic investigations have revealed that Lewis acid-base pairs (LPs), a combination of Lewis acids (LAs) and Lewis bases (LBs), act in concert to activate epoxide and CO<sub>2</sub>, resulting in the efficient synthesis of various cyclic carbonates with high yields. Various epoxides are converted into cyclic carbonates with yields as high as 99% under cocatalyst-free and solvent-free conditions. Moreover, this homogeneous Lewis pair was incorporated into hypercrosslinked polymers through the Friedel-Crafts reaction, enabling the convenient recovery and reuse of the catalysts.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133651"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133683
Jinhui Song , Tianfu Zhang , Mengjiao Xing , Junfeng Zhou , Lu Tang , Jiaxin Xie , Zimin Peng , Wenyao Gu , Jianyu Tang , Suyao Liu , Tong Chang , Yi Liu , Yiwen Fang
With the potential application of biomass-derived feedstock upgradation to sustainable aviation fuels, it is essential to enhance the hydroisomerization performance of ZSM-22 zeolite while improving its resistance to residual oxygen-containing compounds. As the defect sites in the ZSM-22 zeolite, the abundant Si-OH groups are closely related to the catalytic performance and stability, serving as the main attack sites for the generated water. In this work, liquid-mediated defect-healing treatment is performed to heal Si-OH to Si-O-Si, leading to the enhancement of the crystallinity and pore connectivity without affecting the Si/Al, micropore volume, and morphology and preventing the micropores blockage and dealumination caused by conventional silylation and silication procedures. The outcome of the declined Si-OH groups is the reduction of the Lewis acid site without altering the Brønsted acidity. In the n-dodecane hydroisomerization, the catalyst obtained by the liquid-mediated defect-healing treatment route shows an increased conversion and isomer yield compared to the parent and healed catalysts prepared by other healing methods. This is mainly due to enhanced confinement of the micropore void, resulting in decreased apparent activation energy and reduced yield to multi-branched isomers prone to cracking. Furthermore, the healed catalyst exhibits improved resistance and structure stability in the hydroisomerization of feedstocks containing butanol. The work provides a prospective application of ZSM-22 zeolite in the hydroisomerization for complex and severe reactants through the essential Si-OH healing method.
{"title":"Si-OH defect healing treatments of ZSM-22 zeolites for enhanced performance and alcohol resistance in n-alkanes hydroisomerization","authors":"Jinhui Song , Tianfu Zhang , Mengjiao Xing , Junfeng Zhou , Lu Tang , Jiaxin Xie , Zimin Peng , Wenyao Gu , Jianyu Tang , Suyao Liu , Tong Chang , Yi Liu , Yiwen Fang","doi":"10.1016/j.fuel.2024.133683","DOIUrl":"10.1016/j.fuel.2024.133683","url":null,"abstract":"<div><div>With the potential application of biomass-derived feedstock upgradation to sustainable aviation fuels, it is essential to enhance the hydroisomerization performance of ZSM-22 zeolite while improving its resistance to residual oxygen-containing compounds. As the defect sites in the ZSM-22 zeolite, the abundant Si-OH groups are closely related to the catalytic performance and stability, serving as the main attack sites for the generated water. In this work, liquid-mediated defect-healing treatment is performed to heal Si-OH to Si-O-Si, leading to the enhancement of the crystallinity and pore connectivity without affecting the Si/Al, micropore volume, and morphology and preventing the micropores blockage and dealumination caused by conventional silylation and silication procedures. The outcome of the declined Si-OH groups is the reduction of the Lewis acid site without altering the Brønsted acidity. In the n-dodecane hydroisomerization, the catalyst obtained by the liquid-mediated defect-healing treatment route shows an increased conversion and isomer yield compared to the parent and healed catalysts prepared by other healing methods. This is mainly due to enhanced confinement of the micropore void, resulting in decreased apparent activation energy and reduced yield to multi-branched isomers prone to cracking. Furthermore, the healed catalyst exhibits improved resistance and structure stability in the hydroisomerization of feedstocks containing butanol. The work provides a prospective application of ZSM-22 zeolite in the hydroisomerization for complex and severe reactants through the essential Si-OH healing method.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133683"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133724
Jingyue Wang , Liu Wu , Fanfan Huang , Jie Liang
Co-pyrolysis of biomass and plastic was conducive to aromatics-rich bio-oil production, though the significance of zeolite mesopores in co-pyrolysis was still lacking and required further investigation. Herein, a conventional ZSM-5 and its two mesoporous deviants (hollow HS-ZSM-5 and core–shell hierarchical ZSM-5@SBA-15) were synthesized and utilized as catalysts in the co-pyrolysis of neem sawdust (NS) and high-density polyethylene (HDPE). Results showed that compared to ZSM-5, both the mesoporous zeolites enhanced aromatics production. And HS-ZSM-5 with an interior mesoporous cavity performed better in improving the monocyclic aromatic hydrocarbons (MAHs) fraction. An optimization of co-pyrolysis conditions (e.g., HDPE percentage, catalyst loading, co-pyrolysis temperature) further improved the MAHs selectivity to 33.8 area%. The synergy between NS and HDPE over mesoporous zeolites was also compared. While the aromatization between short-chain olefins was dominant in aromatics production over ZSM-5@SBA-15, the Diels–Alder reaction between NS-derived furans and HDPE-derived olefins contributed more in that over HS-ZSM-5.
{"title":"Co-pyrolysis of neem sawdust and high-density polyethylene towards aromatic-rich bio-oil: Significance of zeolite mesopores","authors":"Jingyue Wang , Liu Wu , Fanfan Huang , Jie Liang","doi":"10.1016/j.fuel.2024.133724","DOIUrl":"10.1016/j.fuel.2024.133724","url":null,"abstract":"<div><div>Co-pyrolysis of biomass and plastic was conducive to aromatics-rich bio-oil production, though the significance of zeolite mesopores in co-pyrolysis was still lacking and required further investigation. Herein, a conventional ZSM-5 and its two mesoporous deviants (hollow HS-ZSM-5 and core–shell hierarchical ZSM-5@SBA-15) were synthesized and utilized as catalysts in the co-pyrolysis of neem sawdust (NS) and high-density polyethylene (HDPE). Results showed that compared to ZSM-5, both the mesoporous zeolites enhanced aromatics production. And HS-ZSM-5 with an interior mesoporous cavity performed better in improving the monocyclic aromatic hydrocarbons (MAHs) fraction. An optimization of co-pyrolysis conditions (<em>e.g.</em>, HDPE percentage, catalyst loading, co-pyrolysis temperature) further improved the MAHs selectivity to 33.8 area%. The synergy between NS and HDPE over mesoporous zeolites was also compared. While the aromatization between short-chain olefins was dominant in aromatics production over ZSM-5@SBA-15, the Diels–Alder reaction between NS-derived furans and HDPE-derived olefins contributed more in that over HS-ZSM-5.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133724"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solid rocket motors (SRM) are essential for national defense, satellite launch vehicles for placing spacecraft for communications, resource management, and space exploration. Numerical modeling of composite solid propellants is very helpful for optimizing performance, ensuring safety, and complementing experimental testing. It provides insights into combustion dynamics and allows for precise customization to meet specific mission needs, so modeling composite propellants will stay important. AP (Ammonium Perchlorate), as a synthetic oxidizer, has been widely utilized in modern composite solid propellants. Therefore, it is crucial to understand the physicochemical processes such as condensed-phase heating and reaction kinetics, the interactions between the condensed and gas phases, and gas-phase combustion. A steady-state numerical simulation model is presented to study the combustion of AP. Zonal modeling is employed to treat the solid phase, melt layer, and gas phase separately with conservation of mass, energy, and species, and the solutions are coupled with appropriate boundary conditions. A simple global reaction is developed, validated, and used for the condensed phase with better surface species profiles than those available in the literature. A detailed reaction mechanism is used in the gas phase combustion. This model considers only liquid as a condensed phase and uses a newly condensed phase mechanism and a premixed AP/HTPB (hydroxyl-terminated polybutadiene) gas phase reaction mechanism instead of AP monopropellant gas phase mechanism. This modeling is a prerequisite for a more sophisticated multi-modal composite propellant model with AP grains and AP/HTPB binder. The predicted burn rate and initial temperature sensitivities for different motor operating pressures match well with experimental and other theoretical data. Also, the simulated melt layer thickness of the present model agrees well with experimental observations. Sensitivity analysis is performed for the melt temperature and activation energy for the condensed phase reaction. The simulation also predicts surface temperature and species profile with reasonable accuracy.
固体火箭发动机（SRM）是国防、卫星运载火箭用于通信、资源管理和太空探索的关键。复合固体推进剂的数值建模非常有助于优化性能、确保安全和补充实验测试。它提供了对燃烧动力学的深入了解，并允许精确定制以满足特定任务的需求，因此复合推进剂建模将继续发挥重要作用。AP（高氯酸铵）作为一种合成氧化剂，已广泛应用于现代复合固体推进剂中。因此，了解凝聚相加热和反应动力学、凝聚相和气相之间的相互作用以及气相燃烧等物理化学过程至关重要。本文提出了一个稳态数值模拟模型来研究 AP 的燃烧。在质量、能量和物种守恒的前提下，采用分区建模法分别处理固相、熔融层和气相，并将解与适当的边界条件耦合。针对凝聚相开发、验证和使用了一种简单的全局反应，其表面物种剖面优于现有文献。气相燃烧采用了详细的反应机制。该模型仅将液体视为凝聚相，并使用了新的凝聚相机理和预混合 AP/HTPB（羟基封端聚丁二烯）气相反应机理，而不是 AP 单推进剂气相机理。该模型是建立包含 AP 粒子和 AP/HTPB 粘合剂的更复杂的多模式复合推进剂模型的先决条件。不同发动机工作压力下的预测燃烧速率和初始温度敏感性与实验数据和其他理论数据十分吻合。此外，本模型模拟的熔层厚度也与实验观测结果十分吻合。对熔体温度和凝聚相反应活化能进行了敏感性分析。模拟还以合理的精度预测了表面温度和物种分布。
{"title":"A multizonal numerical combustion model of ammonium perchlorate","authors":"Neeraj Kumar Pradhan , Jay Patel , Arindrajit Chowdhury , Debasis Chakraborty , Neeraj Kumbhakarna","doi":"10.1016/j.fuel.2024.133742","DOIUrl":"10.1016/j.fuel.2024.133742","url":null,"abstract":"<div><div>Solid rocket motors (SRM) are essential for national defense, satellite launch vehicles for placing spacecraft for communications, resource management, and space exploration. Numerical modeling of composite solid propellants is very helpful for optimizing performance, ensuring safety, and complementing experimental testing. It provides insights into combustion dynamics and allows for precise customization to meet specific mission needs, so modeling composite<!--> <!-->propellants will stay important. AP (Ammonium Perchlorate), as a synthetic oxidizer, has been widely utilized in modern composite solid propellants. Therefore, it is crucial to understand the physicochemical processes such as condensed-phase heating and reaction kinetics, the interactions between the condensed and gas phases, and gas-phase combustion. A steady-state numerical simulation model is presented to study the combustion of AP. Zonal modeling is employed to treat the solid phase, melt layer, and gas phase separately with conservation of mass, energy, and species, and the solutions are coupled with appropriate boundary conditions. A simple global reaction is developed, validated, and used for the condensed phase with better surface species profiles than those available in the literature. A detailed reaction mechanism is used in the gas phase combustion. This model considers only liquid as a condensed phase and uses a newly condensed phase mechanism and a premixed AP/HTPB (hydroxyl-terminated polybutadiene) gas phase reaction mechanism instead of AP monopropellant gas phase mechanism. This modeling is a prerequisite for a more sophisticated multi-modal composite propellant model with AP grains and AP/HTPB binder. The predicted burn rate and initial temperature sensitivities for different motor operating pressures match well with experimental and other theoretical data. Also, the simulated melt layer thickness of the present model agrees well with experimental observations. Sensitivity analysis is performed for the melt temperature and activation energy for the condensed phase reaction. The simulation also predicts surface temperature and species profile with reasonable accuracy.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133742"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.fuel.2024.133739
Natalia R.S. Araujo , Felipe S. Carvalho , Lucimar V. Amaral , João Pedro Braga , Fabrício J.P. Pujatti , Rita C.O. Sebastião
The comprehension of combustion mechanisms enables supervision of reaction rates. By adjusting factors such as heat transfer rates, combustion duration, self-ignition propensity, ignition delay and laminar flame speeds, it is possible to minimize emissions and enhance fuel conversion efficiency in internal combustion engines (ICE). The present study aims to develop and explore a methodology employing an Artificial Neural Network that uses Mass Burned Fraction data as a function of crankshaft angular position to determine combustion kinetics in ICE. The Artificial Neural Network was programmed in this work as a home-made code and produced accurate results. The kinetic triplet consisting of Activation Energy (Ea), Frequency Factor (A) and Reaction Model throughout the combustion process was determined to explore the combustion characteristics of different gasoline formulations and ICE operation conditions. The experimental data were obtained in a Single Cylinder Research Engine (SCRE) operating with gasoline formulations commercialized in Brazil. The methodology determines the kinetics of combustion along the process and recovers the values of Ea and A without resorting to mechanisms that describe each reaction individually, describing, instead, the global contribution of physical models. Because the kinetic models activate the neurons in the hidden layer, they accurately reproduce the experimental Mass Burned Fraction data and bring physical information to the network about the combustion process. The kinetic study showed that the samples with higher values of Ea also had higher ignition delay. The rate constant was also related to the consumption and combustion efficiency during the combustion process, i.e., the fuel with a higher rate constant presents greater combustion efficiency and smaller consumption.
对燃烧机理的了解有助于对反应速率进行监控。通过调整热传导率、燃烧持续时间、自燃倾向、点火延迟和层燃速度等因素，可以最大限度地减少内燃机（ICE）的排放并提高燃料转换效率。本研究旨在开发和探索一种采用人工神经网络的方法，利用质量燃烧分数数据作为曲轴角位置的函数来确定内燃机的燃烧动力学。在这项工作中，人工神经网络以自制代码的形式进行编程，并产生了准确的结果。在整个燃烧过程中，确定了由活化能（Ea）、频率因子（A）和反应模型组成的动力学三要素，以探索不同汽油配方和内燃机车运行条件下的燃烧特性。实验数据是在使用巴西商业化汽油配方的单缸研究发动机（SCRE）上获得的。该方法确定了整个过程中的燃烧动力学，并恢复了 Ea 和 A 值，而不依赖于单独描述每个反应的机制，而是描述了物理模型的整体贡献。由于动力学模型激活了隐藏层中的神经元，因此能准确再现实验中的燃烧质量分数数据，并为网络带来有关燃烧过程的物理信息。动力学研究表明，Ea 值越高的样品点火延迟也越高。速率常数也与燃烧过程中的消耗量和燃烧效率有关，即速率常数越高的燃料燃烧效率越高，消耗量越小。
{"title":"Kinetic study of the combustion process in internal combustion engines: A new methodological approach employing an artificial neural network","authors":"Natalia R.S. Araujo , Felipe S. Carvalho , Lucimar V. Amaral , João Pedro Braga , Fabrício J.P. Pujatti , Rita C.O. Sebastião","doi":"10.1016/j.fuel.2024.133739","DOIUrl":"10.1016/j.fuel.2024.133739","url":null,"abstract":"<div><div>The comprehension of combustion mechanisms enables supervision of reaction rates. By adjusting factors such as heat transfer rates, combustion duration, self-ignition propensity, ignition delay and laminar flame speeds, it is possible to minimize emissions and enhance fuel conversion efficiency in internal combustion engines (ICE). The present study aims to develop and explore a methodology employing an Artificial Neural Network that uses Mass Burned Fraction data as a function of crankshaft angular position to determine combustion kinetics in ICE. The Artificial Neural Network was programmed in this work as a home-made code and produced accurate results. The kinetic triplet consisting of Activation Energy (E<sub>a</sub>), Frequency Factor (A) and Reaction Model throughout the combustion process was determined to explore the combustion characteristics of different gasoline formulations and ICE operation conditions. The experimental data were obtained in a Single Cylinder Research Engine (SCRE) operating with gasoline formulations commercialized in Brazil. The methodology determines the kinetics of combustion along the process and recovers the values of E<sub>a</sub> and A without resorting to mechanisms that describe each reaction individually, describing, instead, the global contribution of physical models. Because the kinetic models activate the neurons in the hidden layer, they accurately reproduce the experimental Mass Burned Fraction data and bring physical information to the network about the combustion process. The kinetic study showed that the samples with higher values of E<sub>a</sub> also had higher ignition delay. The rate constant was also related to the consumption and combustion efficiency during the combustion process, i.e., the fuel with a higher rate constant presents greater combustion efficiency and smaller consumption.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133739"},"PeriodicalIF":6.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.fuel.2024.133700
Mengbin Wang , Suling Yao , Xianshu Dong , Yupin Fan , Xiangning Bu , Guichuan Ye , Zechen Liu , Yujin Sun , Ming Chang , Maoqing Yang
The presence of interfacial microbubbles (IMBs) transforms the particle-bubble interaction process into a more complex particle-microbubble-floatation bubble system. Additionally, the high-speed collisions between deformable gas–liquid interfaces of different scales led to a higher level of physical complexity. However, there has been limited research on the particle-microbubble-floatation bubble interaction process. A high-speed camera was used in this study to investigate the precipitation and growth of IMBs on the coal surface in situ and to explore the impact of IMBs on the dynamic collision and adhesion processes. Observations of IMBs precipitation revealed that it was related to the air saturation in water. The precipitation sites were selective, mainly occurring from the pores and cracks on coal surface. As the precipitation time increased (from 2 to 60 min), the quantity of IMBs remained nearly unchanged, but their diameter and coverage rate increased, and the contact angle () decreased. Based on the frame-by-frame analysis of the dynamic collisions and adhesion processes between bubbles and coal surface, it was found that the bubble rebound number, rebound time, induction time and adhesion time all decreased in the presence of IMBs. Meanwhile, the kinetic energy () of the bubble that the coal surface can capture, adhesion diameter, and adhesion contact angle increased. The presence of IMBs can enhance the foam film drainage rate and form gas capillary bridges once the foam film ruptures, which helps the coal surface capture bubbles with greater and allows the bubble to enter the spreading stage more quickly. Additionally, the curved foam film formed between bubble and IMBs provides extra surface tension for the spreading of the three-phase contact (TPC) line. IMBs increase the probability and stability of bubble-coal adhesion. Furthermore, it was revealed that the microbubble morphology (diameter and contact angle) could affect the bubble-coal dynamic collision and adhesion processes. IMBs with a precipitation time of 5 min (diameter of 134 μm and of 47.1°) exhibited the best performance. This is mainly determined by the difficulty of bubble-IMBs coalescence, the increase in diameter after coalescence, and the possibility of consecutive coalescence. The findings of this study can provide new insights into using interface microbubbles to enhance the flotation yield and rate of coal particles, as well as to innovate flotation processes.
{"title":"Effect of in-situ microbubbles precipitated at the solid–liquid interface on the bubble-coal dynamic collision and adhesion processes","authors":"Mengbin Wang , Suling Yao , Xianshu Dong , Yupin Fan , Xiangning Bu , Guichuan Ye , Zechen Liu , Yujin Sun , Ming Chang , Maoqing Yang","doi":"10.1016/j.fuel.2024.133700","DOIUrl":"10.1016/j.fuel.2024.133700","url":null,"abstract":"<div><div>The presence of interfacial microbubbles (IMBs) transforms the particle-bubble interaction process into a more complex particle-microbubble-floatation bubble system. Additionally, the high-speed collisions between deformable gas–liquid interfaces of different scales led to a higher level of physical complexity. However, there has been limited research on the particle-microbubble-floatation bubble interaction process. A high-speed camera was used in this study to investigate the precipitation and growth of IMBs on the coal surface in situ and to explore the impact of IMBs on the dynamic collision and adhesion processes. Observations of IMBs precipitation revealed that it was related to the air saturation in water. The precipitation sites were selective, mainly occurring from the pores and cracks on coal surface. As the precipitation time increased (from 2 to 60 min), the quantity of IMBs remained nearly unchanged, but their diameter and coverage rate increased, and the contact angle (<span><math><mrow><msub><mi>θ</mi><mi>m</mi></msub></mrow></math></span>) decreased. Based on the frame-by-frame analysis of the dynamic collisions and adhesion processes between bubbles and coal surface, it was found that the bubble rebound number, rebound time, induction time and adhesion time all decreased in the presence of IMBs. Meanwhile, the kinetic energy (<span><math><mrow><msub><mi>E</mi><mi>K</mi></msub></mrow></math></span>) of the bubble that the coal surface can capture, adhesion diameter, and adhesion contact angle increased. The presence of IMBs can enhance the foam film drainage rate and form gas capillary bridges once the foam film ruptures, which helps the coal surface capture bubbles with greater <span><math><mrow><msub><mi>E</mi><mi>K</mi></msub></mrow></math></span> and allows the bubble to enter the spreading stage more quickly. Additionally, the curved foam film formed between bubble and IMBs provides extra surface tension for the spreading of the three-phase contact (TPC) line. IMBs increase the probability and stability of bubble-coal adhesion. Furthermore, it was revealed that the microbubble morphology (diameter and contact angle) could affect the bubble-coal dynamic collision and adhesion processes. IMBs with a precipitation time of 5 min (diameter of 134 μm and <span><math><mrow><msub><mi>θ</mi><mi>m</mi></msub></mrow></math></span> of 47.1°) exhibited the best performance. This is mainly determined by the difficulty of bubble-IMBs coalescence, the increase in diameter after coalescence, and the possibility of consecutive coalescence. The findings of this study can provide new insights into using interface microbubbles to enhance the flotation yield and rate of coal particles, as well as to innovate flotation processes.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"382 ","pages":"Article 133700"},"PeriodicalIF":6.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The expansion of global population and industrialization has resulted in an increasing demand for energy in various sectors including petrochemicals, energy storage, pharmaceuticals, and electronics and electricals leads to several challenges such as environmental degradation, conventional resource depletion, and energy insecurity. As a result, for balancing daily energy needs efficient and sustainable energy storage solutions, such as supercapacitors are required that provide rapid energy storage and release, along with long cycle life and minimal environmental impact. While existing literature primarily discusses conventional materials for energy storage which lacks comprehensive analysis of fabrication strategies and morphological structures of biomass-based electrodes. Therefore, the present review comprehensively highlights the substantial potential of carbonized biomass precursors as a sustainable alternative. Several fabrication strategies for carbonized biomass concerning various morphological dimensions such as zero dimensional (0-D), one dimensional (1-D), two dimensional (2-D), and three dimensional (3-D) are comprehensively explored for enhanced electrode performance, along with recent advancements in biomass conversion and activation techniques. In addition, the influence of nanostructure-based dopants on the performance of biomass-derived carbon electrodes, especially focusing on the charge transfer efficiency, cycling stability, and energy storage capacity is thoroughly discussed. Furthermore, the review addresses current challenges and future directions for synthesizing nanostructure-doped carbonized biomass materials for large-scale supercapacitor applications. Thus, this review offers a valuable source for researchers and industries seeking to innovate in sustainable energy storage solutions by bridging the existing knowledge gaps.
{"title":"A critical review on nanostructure-doped carbonized biomass: A new Era in sustainable supercapacitor technology","authors":"Krishna Kumar , Uplabdhi Tyagi , Sidhharth Sirohi , Ritesh Kumar , Saurav Kumar Maity , Nikita , Shagun Singh , Gulshan Kumar","doi":"10.1016/j.fuel.2024.133707","DOIUrl":"10.1016/j.fuel.2024.133707","url":null,"abstract":"<div><div>The expansion of global population and industrialization has resulted in an increasing demand for energy in various sectors including petrochemicals, energy storage, pharmaceuticals, and electronics and electricals leads to several challenges such as environmental degradation, conventional resource depletion, and energy insecurity. As a result, for balancing daily energy needs efficient and sustainable energy storage solutions, such as supercapacitors are required that provide rapid energy storage and release, along with long cycle life and minimal environmental impact. While existing literature primarily discusses conventional materials for energy storage which lacks comprehensive analysis of fabrication strategies and morphological structures of biomass-based electrodes. Therefore, the present review comprehensively highlights the substantial potential of carbonized biomass precursors as a sustainable alternative. Several fabrication strategies for carbonized biomass concerning various morphological dimensions such as zero dimensional (0-D), one dimensional (1-D), two dimensional (2-D), and three dimensional (3-D) are comprehensively explored for enhanced electrode performance, along with recent advancements in biomass conversion and activation techniques. In addition, the influence of nanostructure-based dopants on the performance of biomass-derived carbon electrodes, especially focusing on the charge transfer efficiency, cycling stability, and energy storage capacity is thoroughly discussed. Furthermore, the review addresses current challenges and future directions for synthesizing nanostructure-doped carbonized biomass materials for large-scale supercapacitor applications. Thus, this review offers a valuable source for researchers and industries seeking to innovate in sustainable energy storage solutions by bridging the existing knowledge gaps.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"381 ","pages":"Article 133707"},"PeriodicalIF":6.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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