Pub Date : 2025-03-06DOI: 10.1016/j.powtec.2025.120858
Gislane Pinho de Oliveira , Iñaki Adánez-Rubio , Juan Adánez , Dulce Maria de Araújo Melo , Renata Martins Braga
Finding a suitable oxygen carrier that is both cost-effective and highly reactive across multiple cycles in chemical looping processes remains a challenge. Consequently, this research focuses on the assessment of Fe-, Mn-, and Ni-based ores and mine residues as low-cost and sustainable oxygen carriers. Chemical composition, crushing strength, and attrition rate were determined. Their reactivity was evaluated in a thermobalance with CH4, H2, and CO, followed by assessment in a batch fluidized bed reactor with the same gases. All materials exhibited good mechanical properties at the outset, except MinMnT, which lacked the required mechanical strength and was subjected to thermal treatment. MinFeC, MinFeF, and MinMnT1000 demonstrated effective oxygen transport capacity and high reactivity both in thermobalance and FBR, with no agglomeration and a lifetime ranging between 3000 and 10,500 h. Given the outstanding performance of MinMnT1000 with CO and H2, it is considered an excellent candidate for further evaluation in iG-CLC with biomass.
{"title":"Screening of Fe-, Mn-, and Ni-based ores and mine residues as sustainable, environmentally friendly, and cost-effective oxygen carriers for chemical looping processes","authors":"Gislane Pinho de Oliveira , Iñaki Adánez-Rubio , Juan Adánez , Dulce Maria de Araújo Melo , Renata Martins Braga","doi":"10.1016/j.powtec.2025.120858","DOIUrl":"10.1016/j.powtec.2025.120858","url":null,"abstract":"<div><div>Finding a suitable oxygen carrier that is both cost-effective and highly reactive across multiple cycles in chemical looping processes remains a challenge. Consequently, this research focuses on the assessment of Fe-, Mn-, and Ni-based ores and mine residues as low-cost and sustainable oxygen carriers. Chemical composition, crushing strength, and attrition rate were determined. Their reactivity was evaluated in a thermobalance with CH<sub>4</sub>, H<sub>2</sub>, and CO, followed by assessment in a batch fluidized bed reactor with the same gases. All materials exhibited good mechanical properties at the outset, except MinMnT, which lacked the required mechanical strength and was subjected to thermal treatment. MinFeC, MinFeF, and MinMnT1000 demonstrated effective oxygen transport capacity and high reactivity both in thermobalance and FBR, with no agglomeration and a lifetime ranging between 3000 and 10,500 h. Given the outstanding performance of MinMnT1000 with CO and H<sub>2</sub>, it is considered an excellent candidate for further evaluation in <em>i</em>G-CLC with biomass.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120858"},"PeriodicalIF":4.5,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.powtec.2025.120879
Zihua Li , Qiang Jin , Chong Shi , Di Hu
Microbial-induced calcite precipitation (MICP) is an eco-friendly soil stabilization technology widely applied to the solidification of aeolian sand. To further enhance the effectiveness of MICP in cementing aeolian sand, this study introduced wheat straw powder (WSP) as a reinforcing material and conducted experimental research on WSP-enhanced microbial cemented aeolian sand. By combining macroscopic physical and mechanical tests with discrete element method (DEM) simulations, this study systematically investigated the mechanisms by which WSP enhances microbial cementation and the mesoscopic failure characteristics of the material. The results indicated that adding WSP significantly increased the calcium carbonate content, resulting in uniform calcite deposition and encapsulation of sand particles. This enhancement increased the compressive strength and deformation resistance of the cemented sand columns, with a notable increase in strain at failure. DEM simulations further revealed that as the calcium carbonate content increased, macroscopic cracks within the sand columns evolved from single to multiple pathways, eventually penetrating the entire sand column along the loading direction. The internal bonding failure process could be divided into compaction, expansion, and rapid growth stages. Additionally, the uniformity of particle bonding in WSP-reinforced sand columns significantly impacted their macroscopic mechanical behavior, with uneven interparticle bonding likely inducing microcrack accumulation, leading to severe fracture patterns. These findings provide valuable insights for optimizing microbial cementation techniques for aeolian sand.
{"title":"Synergistic mechanisms and mesoscopic failure characteristics of wheat straw powder-enhanced microbial cemented aeolian sand","authors":"Zihua Li , Qiang Jin , Chong Shi , Di Hu","doi":"10.1016/j.powtec.2025.120879","DOIUrl":"10.1016/j.powtec.2025.120879","url":null,"abstract":"<div><div>Microbial-induced calcite precipitation (MICP) is an eco-friendly soil stabilization technology widely applied to the solidification of aeolian sand. To further enhance the effectiveness of MICP in cementing aeolian sand, this study introduced wheat straw powder (WSP) as a reinforcing material and conducted experimental research on WSP-enhanced microbial cemented aeolian sand. By combining macroscopic physical and mechanical tests with discrete element method (DEM) simulations, this study systematically investigated the mechanisms by which WSP enhances microbial cementation and the mesoscopic failure characteristics of the material. The results indicated that adding WSP significantly increased the calcium carbonate content, resulting in uniform calcite deposition and encapsulation of sand particles. This enhancement increased the compressive strength and deformation resistance of the cemented sand columns, with a notable increase in strain at failure. DEM simulations further revealed that as the calcium carbonate content increased, macroscopic cracks within the sand columns evolved from single to multiple pathways, eventually penetrating the entire sand column along the loading direction. The internal bonding failure process could be divided into compaction, expansion, and rapid growth stages. Additionally, the uniformity of particle bonding in WSP-reinforced sand columns significantly impacted their macroscopic mechanical behavior, with uneven interparticle bonding likely inducing microcrack accumulation, leading to severe fracture patterns. These findings provide valuable insights for optimizing microbial cementation techniques for aeolian sand.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120879"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578097","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}
Powder beds are widely utilized in various industrial fields. However, the inherent properties of the particles limit their heat transfer performance. One of the most promising solutions to enhance heat transfer is the addition of periodic open cellular structure (POCS) to form packed POCS. However, the effective thermal conductivity (ETC) of packed POCS has been rarely explored. This study aims to enhance the heat transfer performance of powder beds by integrating POCS and establish a predictive framework for their ETC. In this study, the ETC of the powder beds, POCS, and packed POCS was measured. The modified Zehner–Schlünder–Damköhler (ZSD) model was adopted to predict the ETC of the powder beds. A prediction formula for ETC of packed POCS was developed based on the ZSD model. The effects of particle properties on the thermal conductivity of both powder beds and packed POCS were investigated. Results revealed that an increase in solid thermal conductivity (ks) enhanced heat transfer within both powder beds and packed POCS. Reductions in porosity (ε) and packing density (εpacking) enhanced heat transfer within powder beds and packed POCS, respectively. Particle diameter (Dp) had a negligible impact on ETC. POCS has the potential to significantly enhance heat transfer in the powder beds, and the incorporation of POCS into powder beds increased ETC by 2–5 times. In addition, the ETC of packed POCS was accurately predicted using the prediction formula (maximum relative error ≤ 5.7 %).
{"title":"Measurement, prediction, and analysis of effective thermal conductivity of powder beds enhanced by periodic open cellular structure","authors":"Wei Zhou , Xiaofeng Mou , Penghui Feng , Zewei Bao","doi":"10.1016/j.powtec.2025.120883","DOIUrl":"10.1016/j.powtec.2025.120883","url":null,"abstract":"<div><div>Powder beds are widely utilized in various industrial fields. However, the inherent properties of the particles limit their heat transfer performance. One of the most promising solutions to enhance heat transfer is the addition of periodic open cellular structure (POCS) to form packed POCS. However, the effective thermal conductivity (ETC) of packed POCS has been rarely explored. This study aims to enhance the heat transfer performance of powder beds by integrating POCS and establish a predictive framework for their ETC. In this study, the ETC of the powder beds, POCS, and packed POCS was measured. The modified Zehner–Schlünder–Damköhler (ZSD) model was adopted to predict the ETC of the powder beds. A prediction formula for ETC of packed POCS was developed based on the ZSD model. The effects of particle properties on the thermal conductivity of both powder beds and packed POCS were investigated. Results revealed that an increase in solid thermal conductivity (<em>k</em><sub>s</sub>) enhanced heat transfer within both powder beds and packed POCS. Reductions in porosity (<em>ε</em>) and packing density (<em>ε</em><sub>packing</sub>) enhanced heat transfer within powder beds and packed POCS, respectively. Particle diameter (<em>D</em><sub>p</sub>) had a negligible impact on ETC. POCS has the potential to significantly enhance heat transfer in the powder beds, and the incorporation of POCS into powder beds increased ETC by 2–5 times. In addition, the ETC of packed POCS was accurately predicted using the prediction formula (maximum relative error ≤ 5.7 %).</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120883"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.powtec.2025.120882
Hecong Liu , Guannan Liu , Torsten Endres , Christof Schulz
Microwave plasma synthesis of iron nanoparticles is a complex process involving nucleation and growth of particles, and phase transitions. Accurate diagnostics are essential for understanding this process. In this study, we employ optical in situ diagnostics, including line-of-sight attenuation, optical emission spectroscopy, and two-color thermometry, to investigate the synthesis process. We evaluate the effects of different nanoparticle sizes and phases on the diagnostics. Our results demonstrate that while the nanoparticle phase has a limited effect on pyrometric temperature measurements, size variations can introduce significant errors in volume fraction measurements. We observe that an increase in precursor flow rate yields a higher nanoparticle count but results in smaller nanoparticle size, lower nanoparticle temperature, and a more strongly focused nanoparticle stream. The observed thermal radiation indicates successful nanoparticle generation within the plasma zone. This research contributes valuable insight into the process of iron nanoparticle formation and the associated diagnostics.
{"title":"Optical in situ diagnostics of iron nanoparticle aerosols in microwave plasma","authors":"Hecong Liu , Guannan Liu , Torsten Endres , Christof Schulz","doi":"10.1016/j.powtec.2025.120882","DOIUrl":"10.1016/j.powtec.2025.120882","url":null,"abstract":"<div><div>Microwave plasma synthesis of iron nanoparticles is a complex process involving nucleation and growth of particles, and phase transitions. Accurate diagnostics are essential for understanding this process. In this study, we employ optical in situ diagnostics, including line-of-sight attenuation, optical emission spectroscopy, and two-color thermometry, to investigate the synthesis process. We evaluate the effects of different nanoparticle sizes and phases on the diagnostics. Our results demonstrate that while the nanoparticle phase has a limited effect on pyrometric temperature measurements, size variations can introduce significant errors in volume fraction measurements. We observe that an increase in precursor flow rate yields a higher nanoparticle count but results in smaller nanoparticle size, lower nanoparticle temperature, and a more strongly focused nanoparticle stream. The observed thermal radiation indicates successful nanoparticle generation within the plasma zone. This research contributes valuable insight into the process of iron nanoparticle formation and the associated diagnostics.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120882"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.powtec.2025.120881
Lixing Zhang , Gang Guo , Zhenbo Tong , Ya Zhang , Aibing Yu
Inhaled administration is essential for treating asthma, lung cancer and chronic obstructive pulmonary disease (COPD). Breezhaler®, as a low-resistance dry powder inhaler device, has shown excellent performance. Investigating the impact of different airway structures on the deposition mechanisms of Breezhaler® drugs in various characteristic zones is essential for improving inhaler designs and predicting the particle deposition distribution. The primary aim of this study is to systematically examine how individual differences impact the particle distribution and deposition mechanisms in different areas within the inhaler-airways. CFD was conducted to analyze the airflow pattern within these models. DPM was utilized to track the deposition paths of particles. Fourteen realistic airway models with inhalation devices were reconstructed, and the effects of three distinct inhalation airflow rates and particle sizes were analyzed. The results showed that the curvature of the airway and the length of the pharynx increased the likelihood of particle deposition. When the glottis structure had small cross-sectional tips, it caused uneven velocity distribution, but increasing the circularity and equivalent diameter of the glottis could mitigate this effect. For treating deep lung diseases like COPD, a lower inhalation flow rate makes particle size less critical, while higher flow rates require smaller particle sizes for optimal treatment. For bronchiectasis treatment targeting the tracheobronchial region, users with lower inhalation flow rates should use 4 μm particles, and those with higher flow rates should use 2 μm particles. Model 1 shows potential as a representative model for predicting deposition distribution.
{"title":"Numerical study on the effect of individual variations on inhaled drug particle deposition distribution in grouped realistic inhaler-airway models","authors":"Lixing Zhang , Gang Guo , Zhenbo Tong , Ya Zhang , Aibing Yu","doi":"10.1016/j.powtec.2025.120881","DOIUrl":"10.1016/j.powtec.2025.120881","url":null,"abstract":"<div><div>Inhaled administration is essential for treating asthma, lung cancer and chronic obstructive pulmonary disease (COPD). Breezhaler®, as a low-resistance dry powder inhaler device, has shown excellent performance. Investigating the impact of different airway structures on the deposition mechanisms of Breezhaler® drugs in various characteristic zones is essential for improving inhaler designs and predicting the particle deposition distribution. The primary aim of this study is to systematically examine how individual differences impact the particle distribution and deposition mechanisms in different areas within the inhaler-airways. CFD was conducted to analyze the airflow pattern within these models. DPM was utilized to track the deposition paths of particles. Fourteen realistic airway models with inhalation devices were reconstructed, and the effects of three distinct inhalation airflow rates and particle sizes were analyzed. The results showed that the curvature of the airway and the length of the pharynx increased the likelihood of particle deposition. When the glottis structure had small cross-sectional tips, it caused uneven velocity distribution, but increasing the circularity and equivalent diameter of the glottis could mitigate this effect. For treating deep lung diseases like COPD, a lower inhalation flow rate makes particle size less critical, while higher flow rates require smaller particle sizes for optimal treatment. For bronchiectasis treatment targeting the tracheobronchial region, users with lower inhalation flow rates should use 4 μm particles, and those with higher flow rates should use 2 μm particles. Model 1 shows potential as a representative model for predicting deposition distribution.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120881"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.powtec.2025.120862
Yongqi Tong, Jie Cheng, Xi Chen, Haibo Zhao
The chemical looping combustion (CLC) technology, known for its capability to achieve in-situ CO2 separation during fuel combustion, is recognized as one of the most promising carbon capture technologies currently available. CLC technology has recently transitioned from laboratory research to engineering demonstration. To explore the characteristics of the CLC process, an engineering design methodology is established, leading to the design of a 10 MWth CLC unit. A comprehensive computational particle fluid dynamics (CPFD) simulation of this 10 MWth CLC reactor is conducted at full scale, offering detailed hydrodynamic information on gas-solid two-phase reactive flow within the reactor. Pressure balance, flow patterns, and the distribution of various gas components are sequentially analyzed. Crucial multiphase-flow parameters, including gas phase distribution, solid phase distribution, and pressure distribution within the reactor, are acquired, supplementing important details that are usually challenging to obtain in experiments. The results reveal that an automatically-established pressure balance within the system, with the solid circulation rate at the air reactor outlet of 113 kg/s, is attained. The methane conversion fluctuates between 80 and 90 %, achieving a carbon capture efficiency of over 95 %. The lower loop-seal effectively isolates the atmospheres between the air reactor and fuel reactor. The simulation results align well with these of the engineering design, validating the reliability of the engineering design.
{"title":"Engineering design and computational particle fluid dynamics simulation of a 10 MWth CH4-fueled chemical looping combustion reactor","authors":"Yongqi Tong, Jie Cheng, Xi Chen, Haibo Zhao","doi":"10.1016/j.powtec.2025.120862","DOIUrl":"10.1016/j.powtec.2025.120862","url":null,"abstract":"<div><div>The chemical looping combustion (CLC) technology, known for its capability to achieve in-situ CO<sub>2</sub> separation during fuel combustion, is recognized as one of the most promising carbon capture technologies currently available. CLC technology has recently transitioned from laboratory research to engineering demonstration. To explore the characteristics of the CLC process, an engineering design methodology is established, leading to the design of a 10 MW<sub>th</sub> CLC unit. A comprehensive computational particle fluid dynamics (CPFD) simulation of this 10 MW<sub>th</sub> CLC reactor is conducted at full scale, offering detailed hydrodynamic information on gas-solid two-phase reactive flow within the reactor. Pressure balance, flow patterns, and the distribution of various gas components are sequentially analyzed. Crucial multiphase-flow parameters, including gas phase distribution, solid phase distribution, and pressure distribution within the reactor, are acquired, supplementing important details that are usually challenging to obtain in experiments. The results reveal that an automatically-established pressure balance within the system, with the solid circulation rate at the air reactor outlet of 113 kg/s, is attained. The methane conversion fluctuates between 80 and 90 %, achieving a carbon capture efficiency of over 95 %. The lower loop-seal effectively isolates the atmospheres between the air reactor and fuel reactor. The simulation results align well with these of the engineering design, validating the reliability of the engineering design.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120862"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In fluidized bed systems, accurately predicting drag forces is essential for understanding particle-fluid interactions, and the drag force model should be applicable across a wide range of parameters for particles with varying material properties, such as Geldart A, B, and D types. Using fine-grid two-fluid simulation data from periodic sedimentation systems, this study examines the influence of Stokes number St, density ratio DR, dimensionless filter size, and filtered solid volume fraction on the heterogeneous index . For the same St but different DR, decreases as DR increases. Conversely, for the same DR but different St, a critical solid volume fraction of approximately 0.32 is observed: when , increases with larger St, while when , increases with smaller St. Furthermore, approaches unity at high St (St > 20,000) for Geldart D particles. Based on these findings, a unified filtered drag model was developed by incorporating St to capture the impact of material properties. The proposed model demonstrates favorable performance in a posteriori tests across various fluidized beds.
{"title":"A Stokes number-dependent filtered drag model for fluidized gas-particle beds with varying material properties","authors":"Yiming Zhao , Shouzheng Yuan , Xiao Chen , Qiang Zhou","doi":"10.1016/j.powtec.2025.120860","DOIUrl":"10.1016/j.powtec.2025.120860","url":null,"abstract":"<div><div>In fluidized bed systems, accurately predicting drag forces is essential for understanding particle-fluid interactions, and the drag force model should be applicable across a wide range of parameters for particles with varying material properties, such as Geldart A, B, and D types. Using fine-grid two-fluid simulation data from periodic sedimentation systems, this study examines the influence of Stokes number <em>St</em>, density ratio <em>DR</em>, dimensionless filter size, and filtered solid volume fraction <span><math><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mi>s</mi></msub></math></span> on the heterogeneous index <span><math><msub><mi>H</mi><mi>d</mi></msub></math></span>. For the same <em>St</em> but different <em>DR</em>, <span><math><msub><mi>H</mi><mi>d</mi></msub></math></span> decreases as <em>DR</em> increases. Conversely, for the same <em>DR</em> but different <em>St</em>, a critical solid volume fraction <span><math><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mrow><mi>s</mi><mo>,</mo><mi>c</mi></mrow></msub></math></span> of approximately 0.32 is observed: when <span><math><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mi>s</mi></msub><mo><</mo><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mrow><mi>s</mi><mo>,</mo><mi>c</mi></mrow></msub></math></span>, <span><math><msub><mi>H</mi><mi>d</mi></msub></math></span> increases with larger <em>St</em>, while when <span><math><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mi>s</mi></msub><mo>></mo><msub><mover><mi>ϕ</mi><mo>¯</mo></mover><mrow><mi>s</mi><mo>,</mo><mi>c</mi></mrow></msub></math></span>, <span><math><msub><mi>H</mi><mi>d</mi></msub></math></span> increases with smaller <em>St</em>. Furthermore, <span><math><msub><mi>H</mi><mi>d</mi></msub></math></span> approaches unity at high <em>St</em> (<em>St</em> > 20,000) for Geldart D particles. Based on these findings, a unified filtered drag model was developed by incorporating <em>St</em> to capture the impact of material properties. The proposed model demonstrates favorable performance in <em>a posteriori</em> tests across various fluidized beds.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120860"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.powtec.2025.120880
Chunyang Hua , Zongxing Zou , Maolin Fan , Haojie Duan , Yikai Niu , Zhekai Jiang
The mesoscopic parameters of the discrete element model play a vital role in the precise simulation of the shear mechanical behavior exhibited by sliding zone soil. Presently, discrete element simulations of shear behavior in slip belt soils are mainly conducted via triaxial compression tests for the calibration of fine-scale parameters. It has not been found that the parameters are calibrated directly from the results of ring shear tests which are becoming increasingly widely used to study shear mechanical behavior. This study introduces a novel approach for the calibration of discrete element parameters, employing Genetic Algorithm- Back Propagation to effectively simulate the strain softening behavior of sliding zone soil in ring shear tests. The samples utilized in this research are generated through orthogonal design and three-dimensional particle flow code. The Genetic Algorithm- Back Propagation neural network training data were used to establish a nonlinear mapping relationship between the macro and fine mechanical parameters of slip belt soils, and the genetic algorithm was used to find the fine optimal parameters. The indoor ring shear tests were conducted and then compared with the Genetic Algorithm- Back Propagation model inversion results. The findings indicate that the calibration method proposed in this study is capable of rapidly and accurately inverting the meso-mechanical parameters. Building on this, it has been demonstrated that this method is capable of effectively representing the strain softening behavior of rock and soil, thereby enhancing both the efficiency and accuracy of parameter calibration.
{"title":"DEM parameter calibration strategy applied to the strain-softening characteristics of sliding zone soil with the support of GA-BP","authors":"Chunyang Hua , Zongxing Zou , Maolin Fan , Haojie Duan , Yikai Niu , Zhekai Jiang","doi":"10.1016/j.powtec.2025.120880","DOIUrl":"10.1016/j.powtec.2025.120880","url":null,"abstract":"<div><div>The mesoscopic parameters of the discrete element model play a vital role in the precise simulation of the shear mechanical behavior exhibited by sliding zone soil. Presently, discrete element simulations of shear behavior in slip belt soils are mainly conducted via triaxial compression tests for the calibration of fine-scale parameters. It has not been found that the parameters are calibrated directly from the results of ring shear tests which are becoming increasingly widely used to study shear mechanical behavior. This study introduces a novel approach for the calibration of discrete element parameters, employing Genetic Algorithm- Back Propagation to effectively simulate the strain softening behavior of sliding zone soil in ring shear tests. The samples utilized in this research are generated through orthogonal design and three-dimensional particle flow code. The Genetic Algorithm- Back Propagation neural network training data were used to establish a nonlinear mapping relationship between the macro and fine mechanical parameters of slip belt soils, and the genetic algorithm was used to find the fine optimal parameters. The indoor ring shear tests were conducted and then compared with the Genetic Algorithm- Back Propagation model inversion results. The findings indicate that the calibration method proposed in this study is capable of rapidly and accurately inverting the meso-mechanical parameters. Building on this, it has been demonstrated that this method is capable of effectively representing the strain softening behavior of rock and soil, thereby enhancing both the efficiency and accuracy of parameter calibration.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120880"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.powtec.2025.120804
Haile Jose, Swapna Singha Rabha
Multistage fluidized bed reactors (MFBR) offer enhanced gas–solid interactions, longer residence times, and reduced bubble growth compared to conventional fluidized bed reactors, making them promising candidates for carbon capture applications. Understanding the hydrodynamics is crucial for optimizing the reactor design. This study presents a 2D numerical investigation of the hydrodynamics in a two-stage MFBR using the Euler–Euler Two-Fluid model, with the Syamlal O’Brien drag model tuned to experimental minimum fluidization conditions. The predicted pressure drops across the reactor stages closely matched experimental data, validating the model’s accuracy. Key parameters such as clearance height, gas velocity, and particle size were analyzed for their effects on pressure drop, solid holdup, velocity profiles, and solid entrainment flux. Additionally, the power consumption of the MFBR, based on pressure drop, was evaluated and compared to that of a conventional fluidized bed reactor. The results provide critical insights into the hydrodynamic behavior of MFBRs under various operating conditions, offering valuable guidance for optimizing reactor design, particularly for carbon capture using solid sorbents.
{"title":"Optimizing multistage fluidized bed reactor performance: Computational insights and design modifications","authors":"Haile Jose, Swapna Singha Rabha","doi":"10.1016/j.powtec.2025.120804","DOIUrl":"10.1016/j.powtec.2025.120804","url":null,"abstract":"<div><div>Multistage fluidized bed reactors (MFBR) offer enhanced gas–solid interactions, longer residence times, and reduced bubble growth compared to conventional fluidized bed reactors, making them promising candidates for carbon capture applications. Understanding the hydrodynamics is crucial for optimizing the reactor design. This study presents a 2D numerical investigation of the hydrodynamics in a two-stage MFBR using the Euler–Euler Two-Fluid model, with the Syamlal O’Brien drag model tuned to experimental minimum fluidization conditions. The predicted pressure drops across the reactor stages closely matched experimental data, validating the model’s accuracy. Key parameters such as clearance height, gas velocity, and particle size were analyzed for their effects on pressure drop, solid holdup, velocity profiles, and solid entrainment flux. Additionally, the power consumption of the MFBR, based on pressure drop, was evaluated and compared to that of a conventional fluidized bed reactor. The results provide critical insights into the hydrodynamic behavior of MFBRs under various operating conditions, offering valuable guidance for optimizing reactor design, particularly for carbon capture using solid sorbents.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120804"},"PeriodicalIF":4.5,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.powtec.2025.120876
Wenhui Yang , Xianhui Qiu , Chunlong Liu , Guanfei Zhao , Huashan Yan , Xiaomin He , Kaiwei Ding , Qinghao Jiao , Tingsheng Qiu
In this paper, the flotation performance and mechanism of chalcopyrite and molybdenite in persulfate/Fe2+ systems were evaluated for the first time. The flotation results showed that the recovery difference between chalcopyrite and molybdenite was 63.41 % when PS/Fe2+ were used as depressants. Radicals ·OH and SO4-· can be observed in electron paramagnetic resonance analysis, indicating that the addition of PS/Fe2+ constitutes an advanced oxidation process in minerals systems. The free radical quenching experiments further verified that the free radicals depressed chalcopyrite. To explore the mechanism of free radicals, the contact angle, Fourier transform infrared spectroscopy, Cyclic voltammetry curves and X-ray photoelectron spectroscopy measurements were carried out. The results showed that after PS/Fe2+ treatment, the surface of chalcopyrite was covered by oxides/hydroxides, while the surface of molybdenite had little change and still maintained good hydrophobicity. Finally, a possible model for reacting PS/Fe2+ with chalcopyrite was proposed.
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