Pub Date : 2024-09-26DOI: 10.1016/j.partic.2024.09.013
Cong Leng, Chengfeng Sun, Zhehan Liao, Jian Xu
Granular size segregation is an inevitable phenomenon in both natural and industrial processes. To understand the underlying mechanisms and develop effective optimization strategies, it is essential to employ robust methodologies that can quantitatively characterize and evaluate size segregation behaviors in granular systems. This review critically examines a wide variety of state-of-the-art methodologies from recent studies to quantify granular size segregation. The features of these methodologies are extracted and organized into a comprehensive framework. Four key questions are thoroughly discussed: evaluation criteria for identical segregation states, sensitivity to sample size, the influence of sampling division pattern, and the capability of handling multiple-component system. Finally, we provide an outlook on the future development of advanced and effective methodologies for granular size segregation characterization.
{"title":"Quantitative characterization of granular size segregation: A critical review","authors":"Cong Leng, Chengfeng Sun, Zhehan Liao, Jian Xu","doi":"10.1016/j.partic.2024.09.013","DOIUrl":"10.1016/j.partic.2024.09.013","url":null,"abstract":"<div><div>Granular size segregation is an inevitable phenomenon in both natural and industrial processes. To understand the underlying mechanisms and develop effective optimization strategies, it is essential to employ robust methodologies that can quantitatively characterize and evaluate size segregation behaviors in granular systems. This review critically examines a wide variety of state-of-the-art methodologies from recent studies to quantify granular size segregation. The features of these methodologies are extracted and organized into a comprehensive framework. Four key questions are thoroughly discussed: evaluation criteria for identical segregation states, sensitivity to sample size, the influence of sampling division pattern, and the capability of handling multiple-component system. Finally, we provide an outlook on the future development of advanced and effective methodologies for granular size segregation characterization.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 166-177"},"PeriodicalIF":4.1,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.partic.2024.09.014
Renbo Deng , Shiran Li , Qianqian Wang , Jiaying Liang , Xufeng Zang , Huiling Xia
Although a few studies reveal the reasons of poor charge-discharge abilities for lithium-ion batteries based on LiNixMnyCo1-x-yO2 at low temperature, there are still some practical issues worthy of further investigation. For instance, how the side reactions affect the cyclabilities of commercial LiCoO2/artificial graphite (LCO/AG) cells at different low temperatures, and are the synergistic effects between the side reactions similar to that at room temperature? To answer the issues, the performances of a ⁓3 Ah LCO/AG pouch cell at different temperatures and C-rates are studied. Results illustrate that the obvious increase in charge transferring impedance especially in AG anode at low temperature causes large polarization, then reducing charge-discharge ability and even yielding lithium deposition at −10 °C and 0.5C under 3−4.45 V. Different from at room temperature, the side reactions such as electrolyte decomposition and electrode structural evolution reduce significantly at low temperature, which contribute to an excellent cyclability after 500 cycles at 0 °C. Instead, a series of chain reactions cause a relative lower cyclability at 25 °C. Lithium deposition is slight after 5 cycles at −10 °C, but become considerably severe after 20 cycles and cause rollover failure of capacity. All these results deepen the understanding on mechanisms for different behaviors of LCO/AG cells at low temperature and provide optimization direction.
尽管一些研究揭示了基于镍钴锰酸锂-x-二氧化钛的锂离子电池在低温下充放电能力差的原因，但仍有一些实际问题值得进一步研究。例如，副反应如何影响商用钴酸锂/人造石墨（LCO/AG）电池在不同低温下的循环能力？为了回答这些问题，我们研究了⁓3 Ah LCO/AG 袋式电池在不同温度和 C 率下的性能。结果表明，在-10 °C和0.5 °C、3-4.45 V电压条件下，低温下电荷转移阻抗（尤其是 AG 阳极）明显增加，导致极化较大，进而降低充放电能力，甚至产生锂沉积。与室温下不同的是，低温下电解质分解和电极结构演变等副反应显著减少，这有助于在 0 °C 下循环 500 次后获得极佳的循环能力。相反，在 25 °C时，一系列连锁反应导致循环能力相对较低。在-10 °C下循环 5 次后，锂沉积轻微，但循环 20 次后，锂沉积变得相当严重，并导致容量翻转失效。所有这些结果加深了人们对 LCO/AG 电池在低温下的不同行为机理的理解，并为优化提供了方向。
{"title":"Mechanisms for different cyclabilities of commercial LiCoO2/artificial graphite pouch cells at −10, 0, and 25 °C","authors":"Renbo Deng , Shiran Li , Qianqian Wang , Jiaying Liang , Xufeng Zang , Huiling Xia","doi":"10.1016/j.partic.2024.09.014","DOIUrl":"10.1016/j.partic.2024.09.014","url":null,"abstract":"<div><div>Although a few studies reveal the reasons of poor charge-discharge abilities for lithium-ion batteries based on LiNi<sub>x</sub>Mn<sub>y</sub>Co<sub>1-x-y</sub>O<sub>2</sub> at low temperature, there are still some practical issues worthy of further investigation. For instance, how the side reactions affect the cyclabilities of commercial LiCoO<sub>2</sub>/artificial graphite (LCO/AG) cells at different low temperatures, and are the synergistic effects between the side reactions similar to that at room temperature? To answer the issues, the performances of a ⁓3 Ah LCO/AG pouch cell at different temperatures and C-rates are studied. Results illustrate that the obvious increase in charge transferring impedance especially in AG anode at low temperature causes large polarization, then reducing charge-discharge ability and even yielding lithium deposition at −10 °C and 0.5C under 3−4.45 V. Different from at room temperature, the side reactions such as electrolyte decomposition and electrode structural evolution reduce significantly at low temperature, which contribute to an excellent cyclability after 500 cycles at 0 °C. Instead, a series of chain reactions cause a relative lower cyclability at 25 °C. Lithium deposition is slight after 5 cycles at −10 °C, but become considerably severe after 20 cycles and cause rollover failure of capacity. All these results deepen the understanding on mechanisms for different behaviors of LCO/AG cells at low temperature and provide optimization direction.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 145-153"},"PeriodicalIF":4.1,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25DOI: 10.1016/j.partic.2024.09.011
Jiangkai Ma , Jingjing Meng , Yanhui Wang , Xuan Liu , Xiaoting Zhang , Kaiyue Yang , Qiang Liu , Zhanfang Hou
Oxalic acid (C2) is a significant tracer of secondary organic aerosols (SOA), yet its precursors, evolutionary processes, and formation mechanisms are not fully understood. This knowledge gap leads to uncertainties in evaluating the climate effect and global budget of SOA. Here we compared the size distribution, mixing fraction, and evolutionary mechanism of C2-containing particles between summer and winter. In summer, the number of C2 particles and their homologs decreased compared to winter. However, the proportion of C2 relative to the total number of determined particles increased, indicating that the summertime particles are more aged. Higher relative aerosol acidity (Rra) and lower in-situ pH (pHis) in summer suggest that particles are more acidic during this season. Correlation analysis and temporal variation characteristics suggest that from 9: 00 to 15: 00 in summer, C2 particles mostly originate from the photochemical decomposition of larger dicarboxylic aids, driven by O3 concentration. Conversely, from 16: 00 to 20: 00, C2 particles are predominantly formed through aqueous-phase oxidation, influenced by higher relative humidity (RH), aerosol liquid water content (ALWC), and acidity. Additionally, heavy metal particles were the predominant type of C2 particles, and C2 particles exhibited an opposite diurnal variation to Fe in summer, suggesting that the photolysis of iron oxalate complexes is an important sink of C2 particles during this period. In winter, biomass burning (BB) particles were the most abundant, and a robust correlation between levoglucosan and C2 particles indicated a substantial influence of BB on C2 particles. The aqueous generation of C2 particles from α-dicarbonyls driven by acidity was most effective when RH varied from 40% to 60% in the wintertime state of particles. These findings highlight the hourly and seasonal variations in the sources and evolutionary processes of SOA. Such variations must be considered in developing control measures and simulating the climate effect of SOA.
{"title":"Mixing state and evolutionary mechanism of oxalic acid homologs in Liaocheng, East China: Insights from seasonal and hourly observations","authors":"Jiangkai Ma , Jingjing Meng , Yanhui Wang , Xuan Liu , Xiaoting Zhang , Kaiyue Yang , Qiang Liu , Zhanfang Hou","doi":"10.1016/j.partic.2024.09.011","DOIUrl":"10.1016/j.partic.2024.09.011","url":null,"abstract":"<div><div>Oxalic acid (C<sub>2</sub>) is a significant tracer of secondary organic aerosols (SOA), yet its precursors, evolutionary processes, and formation mechanisms are not fully understood. This knowledge gap leads to uncertainties in evaluating the climate effect and global budget of SOA. Here we compared the size distribution, mixing fraction, and evolutionary mechanism of C<sub>2</sub>-containing particles between summer and winter. In summer, the number of C<sub>2</sub> particles and their homologs decreased compared to winter. However, the proportion of C<sub>2</sub> relative to the total number of determined particles increased, indicating that the summertime particles are more aged. Higher relative aerosol acidity (R<sub>ra</sub>) and lower in-situ pH (pH<sub>is</sub>) in summer suggest that particles are more acidic during this season. Correlation analysis and temporal variation characteristics suggest that from 9: 00 to 15: 00 in summer, C<sub>2</sub> particles mostly originate from the photochemical decomposition of larger dicarboxylic aids, driven by O<sub>3</sub> concentration. Conversely, from 16: 00 to 20: 00, C<sub>2</sub> particles are predominantly formed through aqueous-phase oxidation, influenced by higher relative humidity (RH), aerosol liquid water content (ALWC), and acidity. Additionally, heavy metal particles were the predominant type of C<sub>2</sub> particles, and C<sub>2</sub> particles exhibited an opposite diurnal variation to Fe in summer, suggesting that the photolysis of iron oxalate complexes is an important sink of C<sub>2</sub> particles during this period. In winter, biomass burning (BB) particles were the most abundant, and a robust correlation between levoglucosan and C<sub>2</sub> particles indicated a substantial influence of BB on C<sub>2</sub> particles. The aqueous generation of C<sub>2</sub> particles from α-dicarbonyls driven by acidity was most effective when RH varied from 40% to 60% in the wintertime state of particles. These findings highlight the hourly and seasonal variations in the sources and evolutionary processes of SOA. Such variations must be considered in developing control measures and simulating the climate effect of SOA.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 223-234"},"PeriodicalIF":4.1,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.partic.2024.09.009
Xiaoqian Sun , Yunhui Du , Weiyi Zhang , Mengjiao Jin , Ruiang Fan , Peng Zhang
Lithium-rich manganese-based (Li-rich Mn-based) cathode materials possess high specific capacity, low self-discharge rate and steady working voltage, but cycle performance and rate performance need to be further improved. In this study, cathode materials Li1.2Mn0.54Ni0.13Co0.13O2-xFx (x = 0, 0.02, 0.05, 0.08) are synthesized by the co-precipitation method with the two-step calcination process. And the F-doping effects on the microstructure and the electrochemical performance are investigated in the cathode materials Li1.2Mn0.54Ni0.13Co0.13O2. The results indicate that among all the F-doped cathode materials, the crystal lattice parameters are increased, order degree and stability of the layered structure are improved. As for x = 0.05, cathode material Li1.2Mn0.54Ni0.13Co0.13O1.95F0.05 (LMO-F0.05) shows the best cycle performance and rate performance with its capacity retention rate 87.7% after 100 cycles at 0.2 C and discharge capacity 117 mAh g−1 at 5 C high power. It can be seen that F doping is a simple and crucial strategy to promote the Li ion diffusion and develop high performance layered cathode materials.
富锂锰基（Li-rich Mn-based）正极材料具有高比容量、低自放电率和稳定的工作电压，但循环性能和速率性能有待进一步提高。本研究采用共沉淀法和两步煅烧法合成了 Li1.2Mn0.54Ni0.13Co0.13O2-xFx (x = 0, 0.02, 0.05, 0.08) 阴极材料。研究了掺杂 F 对正极材料 Li1.2Mn0.54Ni0.13Co0.13O2 的微观结构和电化学性能的影响。结果表明，在所有掺杂 F 的阴极材料中，晶格参数都得到了提高，层状结构的有序度和稳定性也得到了改善。当 x = 0.05 时，阴极材料 Li1.2Mn0.54Ni0.13Co0.13O1.95F0.05 （LMO-F0.05）的循环性能和速率性能最好，在 0.2 C 下循环 100 次后容量保持率为 87.7%，在 5 C 大功率下放电容量为 117 mAh g-1。由此可见，掺杂 F 是促进锂离子扩散和开发高性能层状阴极材料的一种简单而关键的策略。
{"title":"F-doping effects on microstructure and electrochemical performance of cathode material Li1.2Mn0.54Ni0.13Co0.13O2","authors":"Xiaoqian Sun , Yunhui Du , Weiyi Zhang , Mengjiao Jin , Ruiang Fan , Peng Zhang","doi":"10.1016/j.partic.2024.09.009","DOIUrl":"10.1016/j.partic.2024.09.009","url":null,"abstract":"<div><div>Lithium-rich manganese-based (Li-rich Mn-based) cathode materials possess high specific capacity, low self-discharge rate and steady working voltage, but cycle performance and rate performance need to be further improved. In this study, cathode materials Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2-x</sub>F<sub>x</sub> (x = 0, 0.02, 0.05, 0.08) are synthesized by the co-precipitation method with the two-step calcination process. And the F-doping effects on the microstructure and the electrochemical performance are investigated in the cathode materials Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub>. The results indicate that among all the F-doped cathode materials, the crystal lattice parameters are increased, order degree and stability of the layered structure are improved. As for x = 0.05, cathode material Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>1.95</sub>F<sub>0.05</sub> (LMO-F<sub>0.05</sub>) shows the best cycle performance and rate performance with its capacity retention rate 87.7% after 100 cycles at 0.2 C and discharge capacity 117 mAh g<sup>−1</sup> at 5 C high power. It can be seen that F doping is a simple and crucial strategy to promote the Li ion diffusion and develop high performance layered cathode materials.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 82-91"},"PeriodicalIF":4.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.partic.2024.09.010
Bojian Qi , Yong Yan , Wenbiao Zhang
Flow dynamics of binary particles are investigated to realize the monitoring and optimization of fluidized beds. It is a challenge to accurately classify the mass fraction of mixed biomass, considering the limitations of existing techniques. The data collected from an electrostatic sensor array is analyzed. Cross correlation, empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) are applied to process the signals. Under a higher mass fraction of the wood sawdust, the segregation behavior occurs, and the high energy region of HHT spectrum increases. Furthermore, two data-driven models are trained based on a hybrid wavelet scattering transform and bidirectional long short-term memory (ST-BiLSTM) network and a EMD and BiLSTM (EMD-BiLSTM) network to identify the mass fractions of the mixed biomass, with accuracies of 92% and 99%. The electrostatic sensing combined with the EMD-BiLSTM model is effective to classify the mass fraction of the mixed biomass.
{"title":"Investigations into the flow dynamics of mixed biomass particles in a fluidized bed through Hilbert-Huang transformation and data-driven modelling","authors":"Bojian Qi , Yong Yan , Wenbiao Zhang","doi":"10.1016/j.partic.2024.09.010","DOIUrl":"10.1016/j.partic.2024.09.010","url":null,"abstract":"<div><div>Flow dynamics of binary particles are investigated to realize the monitoring and optimization of fluidized beds. It is a challenge to accurately classify the mass fraction of mixed biomass, considering the limitations of existing techniques. The data collected from an electrostatic sensor array is analyzed. Cross correlation, empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) are applied to process the signals. Under a higher mass fraction of the wood sawdust, the segregation behavior occurs, and the high energy region of HHT spectrum increases. Furthermore, two data-driven models are trained based on a hybrid wavelet scattering transform and bidirectional long short-term memory (ST-BiLSTM) network and a EMD and BiLSTM (EMD-BiLSTM) network to identify the mass fractions of the mixed biomass, with accuracies of 92% and 99%. The electrostatic sensing combined with the EMD-BiLSTM model is effective to classify the mass fraction of the mixed biomass.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 115-123"},"PeriodicalIF":4.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.partic.2024.09.006
Chenglong Jiang , Yajing Liu , Lingling Zeng , Chengshun Xu , Peng Cao
An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method (DEM) under flexible boundary loading conditions. A series triaxial drainage shear test (DEM simulations), in conjunction with the flexible boundary technique, of were performed for sand samples subjected to various physical states and with different particle size distributions. After carefully investigating the critical status of the results of the numerical calculation, the macroscopic failure modes and shear band evolution of sand, as well as the velocity vector field due to different initial states, were explored and classified. Furthermore, the evaluation rules and discrepancies between overall void ratios of the specimen and local void ratios within the shear band under the critical state were recorded and analyzed. The results proved that a sample with a small void tends to form a shear band, and the rotation of the particles in the non-shear zone is negligible. Conversely, sandy soil with large initial void ratios exhibited limited development of significant shear bands, and the change in void ratios within the shear region and the non-shear area are not significant. Interestingly, the particle-size distribution exerts minimal influence on the evolution rule which the void ratio converges within the shear band and diverges outside the shear region for both multi-stage and single-stage specimens. The void ratio within the shear band and deviator stress ratio tend to exhibit consistently for the same specimen with different initial physical states, thereby distinguishing the critical state. There is a significantly higher change in void ratio within the shear band compared to outside of it, yet it remains stable within a relatively similar range. Additionally, the invariant of the fabric tensor used to describe the critical state characteristics also demonstrates a high degree of consistency within the shear band. These findings strongly indicate that the critical state exists within the shear failure surface and is highly likely to be unique.
{"title":"Critical state uniqueness of dense granular materials using discrete element method in conjunction with flexible membrane boundary","authors":"Chenglong Jiang , Yajing Liu , Lingling Zeng , Chengshun Xu , Peng Cao","doi":"10.1016/j.partic.2024.09.006","DOIUrl":"10.1016/j.partic.2024.09.006","url":null,"abstract":"<div><div>An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method (DEM) under flexible boundary loading conditions. A series triaxial drainage shear test (DEM simulations), in conjunction with the flexible boundary technique, of were performed for sand samples subjected to various physical states and with different particle size distributions. After carefully investigating the critical status of the results of the numerical calculation, the macroscopic failure modes and shear band evolution of sand, as well as the velocity vector field due to different initial states, were explored and classified. Furthermore, the evaluation rules and discrepancies between overall void ratios of the specimen and local void ratios within the shear band under the critical state were recorded and analyzed. The results proved that a sample with a small void tends to form a shear band, and the rotation of the particles in the non-shear zone is negligible. Conversely, sandy soil with large initial void ratios exhibited limited development of significant shear bands, and the change in void ratios within the shear region and the non-shear area are not significant. Interestingly, the particle-size distribution exerts minimal influence on the evolution rule which the void ratio converges within the shear band and diverges outside the shear region for both multi-stage and single-stage specimens. The void ratio within the shear band and deviator stress ratio tend to exhibit consistently for the same specimen with different initial physical states, thereby distinguishing the critical state. There is a significantly higher change in void ratio within the shear band compared to outside of it, yet it remains stable within a relatively similar range. Additionally, the invariant of the fabric tensor used to describe the critical state characteristics also demonstrates a high degree of consistency within the shear band. These findings strongly indicate that the critical state exists within the shear failure surface and is highly likely to be unique.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 124-144"},"PeriodicalIF":4.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.partic.2024.09.007
Weijian Song , Zihua Tang , Guoliang Song , Jianguo Zhu , Jingzhang Liu , Haiyang Wang , Yinjiang Zhang
The circulating fluidized bed (CFB) boiler is an essential option, serving as a flexible power source. However, it is notable that CFB boilers exhibit noticeable limitations in rapid load changes. This study delved into the impact of fuel characteristics on CFB load change rate, combustion efficiency, and original NOx emissions using a 2 MW CFB experimental platform. The findings revealed that blending pulverized coal or modified fuel positively influenced the improvement of CFB load change rate, with blending modified fuel showing a more significant effect. Blending the modified fuel and pulverized coal increased the load change rate within the 50%–100% range by 164.4% and 57.3%, respectively. Additionally, blending pulverized coal and modified fuel significantly reduced NOx emissions, although there remained room for improvement in combustion efficiency. Compared to conventional combustion, blending pulverized coal and blending modified fuel decreased NOx emissions by 35.9% and 41.4% at 100% load, respectively.
{"title":"Experimental study on variable load regulation of circulating fluidized bed with high temperature preheated activated fuel","authors":"Weijian Song , Zihua Tang , Guoliang Song , Jianguo Zhu , Jingzhang Liu , Haiyang Wang , Yinjiang Zhang","doi":"10.1016/j.partic.2024.09.007","DOIUrl":"10.1016/j.partic.2024.09.007","url":null,"abstract":"<div><div>The circulating fluidized bed (CFB) boiler is an essential option, serving as a flexible power source. However, it is notable that CFB boilers exhibit noticeable limitations in rapid load changes. This study delved into the impact of fuel characteristics on CFB load change rate, combustion efficiency, and original NO<sub><em>x</em></sub> emissions using a 2 MW CFB experimental platform. The findings revealed that blending pulverized coal or modified fuel positively influenced the improvement of CFB load change rate, with blending modified fuel showing a more significant effect. Blending the modified fuel and pulverized coal increased the load change rate within the 50%–100% range by 164.4% and 57.3%, respectively. Additionally, blending pulverized coal and modified fuel significantly reduced NO<sub><em>x</em></sub> emissions, although there remained room for improvement in combustion efficiency. Compared to conventional combustion, blending pulverized coal and blending modified fuel decreased NO<sub><em>x</em></sub> emissions by 35.9% and 41.4% at 100% load, respectively.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 178-188"},"PeriodicalIF":4.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.partic.2024.09.005
Letícia Siqueira , Cristiano Augusto Ballus , Eduardo Hiromitsu Tanabe , Daniel Assumpção Bertuol
Vitamin E, a soluble antioxidant widely used in the food and pharmaceutical industries, is rich in tocopherols and phytosterols. Since vitamin E molecules are highly sensitive to oxidation, encapsulation is a viable and effective technique for preservation of the properties of Vitamin E and improving its stability during storage, maintaining the nutritional value. In this work, the aim was to encapsulate concentrated vitamin E using a combination of Ultra-Turrax and ultrasonication to achieve higher encapsulation efficiency in spray drying. In the first stage, the vitamin E oil was encapsulated employing only Ultra-Turrax homogenization, with subsequent optimization of spray drying. The coating materials used were maltodextrin and whey protein isolate. Optimization of the spray drying step evaluated the effects of the drying air temperature (T) and the feed flow rate (Q), to obtain better yields and a high-quality product. In the second stage, the use of ultrasonication in an additional homogenization step was evaluated, aiming to further improve the encapsulation process. The results showed that the best drying conditions (first stage) were T = 180 °C and Q = 0.6 L/h, which provided the highest yield (67.73%) and high encapsulation efficiency (73.73%). The microspheres produced had similar properties, with mean diameters ranging from 0.64 to 12.99 μm. In the second stage of the investigation, the application of ultrasonication immediately after the Ultra-Turrax homogenization enabled the encapsulation efficiency to be increased to 94.05%, with a yield of 57.54%, using an ultrasonication time of only 7 min. This showed that addition of the ultrasonic homogenization step to the process greatly improved the encapsulation efficiency and could be used to produce vitamin E-enriched powder microcapsules by spray drying, with application in the food industry.
维生素 E 是一种广泛应用于食品和制药行业的可溶性抗氧化剂，富含生育酚和植物甾醇。由于维生素 E 分子对氧化非常敏感，因此封装是一种可行且有效的技术，可以保存维生素 E 的特性，提高其在储存过程中的稳定性，保持其营养价值。在这项工作中，目的是利用 Ultra-Turrax 和超声波相结合的方法封装浓缩维生素 E，从而在喷雾干燥中实现更高的封装效率。在第一阶段，仅使用 Ultra-Turrax 均质法封装维生素 E 油，随后对喷雾干燥进行了优化。使用的包衣材料是麦芽糊精和分离乳清蛋白。喷雾干燥步骤的优化评估了干燥空气温度（T）和进料流速（Q）的影响，以获得更好的产量和高质量的产品。在第二阶段，评估了在额外的均质化步骤中使用超声波的情况，目的是进一步改进封装过程。结果表明，最佳干燥条件（第一阶段）为 T = 180 °C 和 Q = 0.6 L/h，产量最高（67.73%），封装效率高（73.73%）。生产的微球具有相似的特性，平均直径在 0.64 至 12.99 μm 之间。在第二阶段的研究中，Ultra-Turrax 均质化后立即使用超声波处理，使封装效率提高到 94.05%，产量为 57.54%，超声波处理时间仅为 7 分钟。这表明，在工艺中加入超声波均质步骤大大提高了封装效率，可用于通过喷雾干燥法生产富含维生素 E 的粉末微胶囊，并可应用于食品工业。
{"title":"Combining Ultra-Turrax and ultrasonic homogenization to achieve higher vitamin E encapsulation efficiency in spray drying","authors":"Letícia Siqueira , Cristiano Augusto Ballus , Eduardo Hiromitsu Tanabe , Daniel Assumpção Bertuol","doi":"10.1016/j.partic.2024.09.005","DOIUrl":"10.1016/j.partic.2024.09.005","url":null,"abstract":"<div><div>Vitamin E, a soluble antioxidant widely used in the food and pharmaceutical industries, is rich in tocopherols and phytosterols. Since vitamin E molecules are highly sensitive to oxidation, encapsulation is a viable and effective technique for preservation of the properties of Vitamin E and improving its stability during storage, maintaining the nutritional value. In this work, the aim was to encapsulate concentrated vitamin E using a combination of Ultra-Turrax and ultrasonication to achieve higher encapsulation efficiency in spray drying. In the first stage, the vitamin E oil was encapsulated employing only Ultra-Turrax homogenization, with subsequent optimization of spray drying. The coating materials used were maltodextrin and whey protein isolate. Optimization of the spray drying step evaluated the effects of the drying air temperature (<em>T</em>) and the feed flow rate (<em>Q</em>), to obtain better yields and a high-quality product. In the second stage, the use of ultrasonication in an additional homogenization step was evaluated, aiming to further improve the encapsulation process. The results showed that the best drying conditions (first stage) were <em>T</em> = 180 °C and <em>Q</em> = 0.6 L/h, which provided the highest yield (67.73%) and high encapsulation efficiency (73.73%). The microspheres produced had similar properties, with mean diameters ranging from 0.64 to 12.99 μm. In the second stage of the investigation, the application of ultrasonication immediately after the Ultra-Turrax homogenization enabled the encapsulation efficiency to be increased to 94.05%, with a yield of 57.54%, using an ultrasonication time of only 7 min. This showed that addition of the ultrasonic homogenization step to the process greatly improved the encapsulation efficiency and could be used to produce vitamin E-enriched powder microcapsules by spray drying, with application in the food industry.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 28-35"},"PeriodicalIF":4.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1016/j.partic.2024.09.004
Yan Zhang , Xinyu Li , Gai Zhang , Mingyang Fan , Jianxin Xu , Hua Wang
Efficient fluid mixing is essential for process intensification. This study proposes a new method in which gas-rigid-flexible composite blades are coupled to enhance chaotic mixing in multiphase flow systems. The rigidity and flexibility of the blades were adjusted by intermittent gas injection, which increased the effectiveness of mixing of the liquid-liquid two-phase fluid. This study investigates the influence of different process parameters on the mixing efficiency and quantifies the chaotic characteristics of fluid mixing through pressure-time series analysis of multiscale entropy and the 0–1 test. A high-speed camera recorded the bubble movement in the flow field, while particle image velocimetry (PIV) revealed the enhancement of the properties of the flow field in the system due to the suspended motion of the particles. Using suitable process parameters, gas-rigid-flexible composite blade coupling significantly enhanced the mixing effect, where the mixing time of the G-RFCP system was reduced by 1.42 times compared to that of the CP system. Bubble motion, deformation, and rupture enhanced the mechanical agitation, increasing the intensity of the turbulence and chaotic behaviour. Flow-field analysis indicated a three-fold increase in the vorticity and a 1.04-fold increase in the velocity difference for the G-RFCP system compared with those of the CP system. This study provides theoretical and experimental foundations for understanding chaotic mixing in liquid-liquid two-phase fluids.
{"title":"Gas-rigid-flexible compound blade coupling enhanced experimental study on chaotic mixing of multiphase flow","authors":"Yan Zhang , Xinyu Li , Gai Zhang , Mingyang Fan , Jianxin Xu , Hua Wang","doi":"10.1016/j.partic.2024.09.004","DOIUrl":"10.1016/j.partic.2024.09.004","url":null,"abstract":"<div><div>Efficient fluid mixing is essential for process intensification. This study proposes a new method in which gas-rigid-flexible composite blades are coupled to enhance chaotic mixing in multiphase flow systems. The rigidity and flexibility of the blades were adjusted by intermittent gas injection, which increased the effectiveness of mixing of the liquid-liquid two-phase fluid. This study investigates the influence of different process parameters on the mixing efficiency and quantifies the chaotic characteristics of fluid mixing through pressure-time series analysis of multiscale entropy and the 0–1 test. A high-speed camera recorded the bubble movement in the flow field, while particle image velocimetry (PIV) revealed the enhancement of the properties of the flow field in the system due to the suspended motion of the particles. Using suitable process parameters, gas-rigid-flexible composite blade coupling significantly enhanced the mixing effect, where the mixing time of the G-RFCP system was reduced by 1.42 times compared to that of the CP system. Bubble motion, deformation, and rupture enhanced the mechanical agitation, increasing the intensity of the turbulence and chaotic behaviour. Flow-field analysis indicated a three-fold increase in the vorticity and a 1.04-fold increase in the velocity difference for the G-RFCP system compared with those of the CP system. This study provides theoretical and experimental foundations for understanding chaotic mixing in liquid-liquid two-phase fluids.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"94 ","pages":"Pages 356-372"},"PeriodicalIF":4.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1016/j.partic.2024.09.002
Christian C. Milioli, Fernando E. Milioli
Sub-grid effective drag, filtered and residual stresses in the meso-scale of gas-particle fluidized flows are intrinsically affected by underlying micro-scale conditions as well as non-local effects related to macro-scale conditions. In this work we applied microscopic two-fluid modeling to experiment with particle Froude number in order to evaluate the impact of this micro-scale condition over the concerning meso-scale derived sub-grid parameters. We performed highly resolved simulations in periodic domains for particle Froude numbers from 12.21 to 799.22, for a wide range of macro-scale conditions. Results were filtered and classified by ranges of meso-scale markers for the various particle Froude numbers. The particle Froude number was found to considerably affect the structural refinement of the heterogeneous flow fields thereby directly impacting effective drag, filtered and residual stresses. All of those parameters showed systematic behaviors in relation to particle Froude number, thereby providing sound data for new sub-grid modeling propositions.
{"title":"Effect of particle Froude number on sub-grid effective drag, filtered and residual stresses in fluidized gas-particle flows","authors":"Christian C. Milioli, Fernando E. Milioli","doi":"10.1016/j.partic.2024.09.002","DOIUrl":"10.1016/j.partic.2024.09.002","url":null,"abstract":"<div><div>Sub-grid effective drag, filtered and residual stresses in the meso-scale of gas-particle fluidized flows are intrinsically affected by underlying micro-scale conditions as well as non-local effects related to macro-scale conditions. In this work we applied microscopic two-fluid modeling to experiment with particle Froude number in order to evaluate the impact of this micro-scale condition over the concerning meso-scale derived sub-grid parameters. We performed highly resolved simulations in periodic domains for particle Froude numbers from 12.21 to 799.22, for a wide range of macro-scale conditions. Results were filtered and classified by ranges of meso-scale markers for the various particle Froude numbers. The particle Froude number was found to considerably affect the structural refinement of the heterogeneous flow fields thereby directly impacting effective drag, filtered and residual stresses. All of those parameters showed systematic behaviors in relation to particle Froude number, thereby providing sound data for new sub-grid modeling propositions.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"95 ","pages":"Pages 36-48"},"PeriodicalIF":4.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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