Pub Date : 2025-02-12DOI: 10.1016/j.cherd.2025.02.005
Ahmet Kececi , Huseyin Topal
This study investigates a circulating fluidized bed steam boiler fueled by biomass from forest wastes in the Marmara Region, Turkey. The gas–solid hydrodynamic structure was investigated both experimentally and numerically to identify existing or potential issues using the MFiX-PIC CFD model. The circulation, facilitated by u-beams acting as impact separators, is governed by pseudo-combustion boundary conditions. The flow direction of secondary air supply nozzles is found to cause problems with water walls and circulation, with gas velocities exceeding 10 m/s. This leads to damage to the water walls and insufficient circulation. Improved hydrodynamics are achieved by adjusting the angles of horizontally positioned secondary air nozzles downward by -20°. This modification results in a slight decrease (-3.77%) in solid particle concentration in the dense phase and a significant increase (+202.69%) in the dilute phase region. Additionally, a discretization scheme study demonstrates that the hybrid composition of the van Leer and Superbee schemes yields a 55.11% faster solution than using Superbee alone and 21.03% faster than using only van Leer. The findings highlight the suitability of the MFiX-PIC model and cost-reducing modeling approaches for industrial-scale steam boiler simulations.
{"title":"Enhancing circulation of particles and gases in a biomass-fueled circulating fluidized bed boiler: A pseudo-combustion case study using MFiX-PIC modeling","authors":"Ahmet Kececi , Huseyin Topal","doi":"10.1016/j.cherd.2025.02.005","DOIUrl":"10.1016/j.cherd.2025.02.005","url":null,"abstract":"<div><div>This study investigates a circulating fluidized bed steam boiler fueled by biomass from forest wastes in the Marmara Region, Turkey. The gas–solid hydrodynamic structure was investigated both experimentally and numerically to identify existing or potential issues using the MFiX-PIC CFD model. The circulation, facilitated by u-beams acting as impact separators, is governed by pseudo-combustion boundary conditions. The flow direction of secondary air supply nozzles is found to cause problems with water walls and circulation, with gas velocities exceeding 10 m/s. This leads to damage to the water walls and insufficient circulation. Improved hydrodynamics are achieved by adjusting the angles of horizontally positioned secondary air nozzles downward by -20°. This modification results in a slight decrease (-3.77%) in solid particle concentration in the dense phase and a significant increase (+202.69%) in the dilute phase region. Additionally, a discretization scheme study demonstrates that the hybrid composition of the van Leer and Superbee schemes yields a 55.11% faster solution than using Superbee alone and 21.03% faster than using only van Leer. The findings highlight the suitability of the MFiX-PIC model and cost-reducing modeling approaches for industrial-scale steam boiler simulations.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 476-493"},"PeriodicalIF":3.7,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-11DOI: 10.1016/j.cherd.2025.02.012
Maria Klippert, Werner Pauer
A non-intrusive method for fouling monitoring using DOFS (Distributed Optical Fiber Sensors) in tubular reactors is presented. The hot spot, caused by the exothermal emulsion polymerization reaction of vinyl acetate and vinyl neodecanoate, was used as a marker to track the fouling progression during the reaction. Due to fouling, the reactor volume was constricted, causing the hot spot to migrate further downstream. This migration was spatially and temporally resolved as a hot spot position-time plot and used describe the time of clogging using mathematical models. From these models, it could be deduced, that the fouling influencing the hot spot is best described by an even constriction of the entire tubular reactor. The mathematical model was able to determine the time of clogging with an accuracy of 0.89–1.28 (with 1 being in perfect agreement with the measured clogging time), starting from 30 min of reaction time. This time is equivalent to 12 % of the entire time of reaction from start to clogging.
{"title":"Determination of the clogging time for continuous emulsion copolymerization in a tubular reactor using distributed optical fiber sensors","authors":"Maria Klippert, Werner Pauer","doi":"10.1016/j.cherd.2025.02.012","DOIUrl":"10.1016/j.cherd.2025.02.012","url":null,"abstract":"<div><div>A non-intrusive method for fouling monitoring using DOFS (Distributed Optical Fiber Sensors) in tubular reactors is presented. The hot spot, caused by the exothermal emulsion polymerization reaction of vinyl acetate and vinyl neodecanoate, was used as a marker to track the fouling progression during the reaction. Due to fouling, the reactor volume was constricted, causing the hot spot to migrate further downstream. This migration was spatially and temporally resolved as a hot spot position-time plot and used describe the time of clogging using mathematical models. From these models, it could be deduced, that the fouling influencing the hot spot is best described by an even constriction of the entire tubular reactor. The mathematical model was able to determine the time of clogging with an accuracy of 0.89–1.28 (with 1 being in perfect agreement with the measured clogging time), starting from 30 min of reaction time. This time is equivalent to 12 % of the entire time of reaction from start to clogging.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 465-475"},"PeriodicalIF":3.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-11DOI: 10.1016/j.cherd.2025.02.011
Yuhang Feng, Jinzhi Gao, Meiling Jiang, Zenan Zhu, Xianghong Lu
The selection of green reaction media with excellent thermal and chemical stability, along with superior heat transfer and dispersion capabilities, is crucial for high-temperature reactions. In this study, various solid powders, including graphite, stainless steel powder, aluminum oxide, and silicon carbide, were evaluated as reaction media for the cyclization-based synthesis of cyclopentane-1,2-dicarboximude at temperatures above 250°C. The relationship between key properties of the solid media—such as thermal conductivity, specific heat capacity, density, and grain size—and their performance in heat transfer and dispersion was systematically investigated. Solid media with high thermal conductivity and specific heat capacity, small grain size, and a density comparable to that of the reactant were found to rapidly bring the system to the target temperature, ensure uniform temperature distribution, and facilitate efficient reactant dispersion, ultimately enhancing the reaction yield and product purity. Based on these findings, graphite with a grain size of 2.6 µm was selected as the optimal reaction medium for the synthesis of cyclopentane-1,2-dicarboximude. The influence of key reaction parameters, such as the reactant-to-media ratio, cyclization temperature, rotational speed and reaction time, was further investigated. Specifically, 4 g of cyclopentane-1,2-dicarboxamide was added to 50 mL of 2.6 µm graphite, and cyclization was conducted at 270°C for 2.5 hours with stirring at 600 rpm. The product was obtained with a 90 % yield and a purity of 99.5 %, which was achievable by simply extracting the product from graphite using room-temperature water. Further recrystallization with acetonitrile can increase the purity of the product to 99.9 %. This study introduces a novel approach to high-temperature reactions and opens new avenues for future research.
{"title":"Selection of reaction media and process optimization for the synthesis of cyclopentane-1,2-dicarboximude in pure solid media: Temperature, concentration distribution and multi-factor analysis","authors":"Yuhang Feng, Jinzhi Gao, Meiling Jiang, Zenan Zhu, Xianghong Lu","doi":"10.1016/j.cherd.2025.02.011","DOIUrl":"10.1016/j.cherd.2025.02.011","url":null,"abstract":"<div><div>The selection of green reaction media with excellent thermal and chemical stability, along with superior heat transfer and dispersion capabilities, is crucial for high-temperature reactions. In this study, various solid powders, including graphite, stainless steel powder, aluminum oxide, and silicon carbide, were evaluated as reaction media for the cyclization-based synthesis of cyclopentane-1,2-dicarboximude at temperatures above 250°C. The relationship between key properties of the solid media—such as thermal conductivity, specific heat capacity, density, and grain size—and their performance in heat transfer and dispersion was systematically investigated. Solid media with high thermal conductivity and specific heat capacity, small grain size, and a density comparable to that of the reactant were found to rapidly bring the system to the target temperature, ensure uniform temperature distribution, and facilitate efficient reactant dispersion, ultimately enhancing the reaction yield and product purity. Based on these findings, graphite with a grain size of 2.6 µm was selected as the optimal reaction medium for the synthesis of cyclopentane-1,2-dicarboximude. The influence of key reaction parameters, such as the reactant-to-media ratio, cyclization temperature, rotational speed and reaction time, was further investigated. Specifically, 4 g of cyclopentane-1,2-dicarboxamide was added to 50 mL of 2.6 µm graphite, and cyclization was conducted at 270°C for 2.5 hours with stirring at 600 rpm. The product was obtained with a 90 % yield and a purity of 99.5 %, which was achievable by simply extracting the product from graphite using room-temperature water. Further recrystallization with acetonitrile can increase the purity of the product to 99.9 %. This study introduces a novel approach to high-temperature reactions and opens new avenues for future research.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 568-579"},"PeriodicalIF":3.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-10DOI: 10.1016/j.cherd.2025.02.007
Raden Tina Rosmalina , Nurrahmi Handayani , Diana Rahayuning Wulan , Ee Ling Yong , Shamila Azman
This study developed and evaluated magnetic molecularly imprinted polymers (MMIPs) for detecting and identifying 4-nonylphenol (NP). The MMIPs were engineered by synthesizing magnetic Fe3O4 particles via co-precipitation, resulting in particles with an average size of approximately 204.7 nm. These particles were subsequently modified with silica using a sol-gel process to form Fe3O4.SiO2. The molecular imprinting process involved polymerizing Fe3O4.SiO2 with a mixture that included NP (template molecule), methacrylic acid (functional monomer), azo(bis)isobutyronitrile (initiator), and ethylene glycol dimethacrylate (cross-linker). Characterization techniques, such as FTIR spectroscopy, confirmed the presence of functional groups, indicating successful modification and imprinting. TGA demonstrated thermal stability up to 250°C, validating the robustness of the synthesized MMIPs. The optimal adsorption capacity was identified at pH 9.989, with a maximum adsorption capacity of 5 mg/g, which shows an enhancement over non-imprinted polymers. Isotherm adsorption studies indicated a better fit for the Freundlich model, with an R squared value of 0.98 for MMIPs, suggesting the occurrence of a multilayer adsorption process. Kinetic studies revealed that the MMIPs adhered to the pseudo-second-order kinetic model, confirming their efficiency in NP adsorption. The reusability test demonstrated that the MMIPs maintained a consistent adsorption capacity over three cycles, with a minimal decrease of 5 %.
{"title":"Removal of 4-nonylphenol using magnetite modified with silica based molecularly imprinted polymers","authors":"Raden Tina Rosmalina , Nurrahmi Handayani , Diana Rahayuning Wulan , Ee Ling Yong , Shamila Azman","doi":"10.1016/j.cherd.2025.02.007","DOIUrl":"10.1016/j.cherd.2025.02.007","url":null,"abstract":"<div><div>This study developed and evaluated magnetic molecularly imprinted polymers (MMIPs) for detecting and identifying 4-nonylphenol (NP). The MMIPs were engineered by synthesizing magnetic Fe<sub>3</sub>O<sub>4</sub> particles via co-precipitation, resulting in particles with an average size of approximately 204.7 nm. These particles were subsequently modified with silica using a sol-gel process to form Fe<sub>3</sub>O<sub>4</sub>.SiO<sub>2</sub>. The molecular imprinting process involved polymerizing Fe<sub>3</sub>O<sub>4</sub>.SiO<sub>2</sub> with a mixture that included NP (template molecule), methacrylic acid (functional monomer), azo(bis)isobutyronitrile (initiator), and ethylene glycol dimethacrylate (cross-linker). Characterization techniques, such as FTIR spectroscopy, confirmed the presence of functional groups, indicating successful modification and imprinting. TGA demonstrated thermal stability up to 250°C, validating the robustness of the synthesized MMIPs. The optimal adsorption capacity was identified at pH 9.989, with a maximum adsorption capacity of 5 mg/g, which shows an enhancement over non-imprinted polymers. Isotherm adsorption studies indicated a better fit for the Freundlich model, with an R squared value of 0.98 for MMIPs, suggesting the occurrence of a multilayer adsorption process. Kinetic studies revealed that the MMIPs adhered to the pseudo-second-order kinetic model, confirming their efficiency in NP adsorption. The reusability test demonstrated that the MMIPs maintained a consistent adsorption capacity over three cycles, with a minimal decrease of 5 %.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 361-373"},"PeriodicalIF":3.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work presents numerical and experimental studies on the turbulent flow in a stirred tank reactor equipped with a two-finger baffle and a retreat blade impeller at Re = 43,200. Numerical results were obtained from Large Eddy Simulation (LES) combined with an Immersed Boundary Method (IBM) for the impeller and baffle representation. The experimental data consists in a set of PIV measurements in a vertical plane containing the shaft axis. The numerical results are compared with experimental data in terms of the flow field, mean velocity components, and kinetic energy. Proper Orthogonal Decomposition (POD) is applied to the IBM-LES results to extract the dominant modes and their time coefficients. The POD analysis suggests that the high energy level found in the upper part of the tank results from an energy transfer from the coherent structures created downstream the two-finger baffle. Finally, the trailing vortices behind the impeller blades and the baffle were detected and visualized using Jeong and Hussain's technique. The results show that IBM-LES is a reliable tool for studying the unsteady characteristics of turbulent flow in agitated tanks with complex geometry.
{"title":"Hydrodynamics in a stirred tank with a retreat blade impeller: Evaluating the potential of IBM-LES through comparison with PIV data","authors":"Seyed Salar Hoseini , Ali Hamieh , Carole Coufort-Saudejaud , Christine Frances , Alain Liné , Jérôme Morchain","doi":"10.1016/j.cherd.2025.02.009","DOIUrl":"10.1016/j.cherd.2025.02.009","url":null,"abstract":"<div><div>This work presents numerical and experimental studies on the turbulent flow in a stirred tank reactor equipped with a two-finger baffle and a retreat blade impeller at Re = 43,200. Numerical results were obtained from Large Eddy Simulation (LES) combined with an Immersed Boundary Method (IBM) for the impeller and baffle representation. The experimental data consists in a set of PIV measurements in a vertical plane containing the shaft axis. The numerical results are compared with experimental data in terms of the flow field, mean velocity components, and kinetic energy. Proper Orthogonal Decomposition (POD) is applied to the IBM-LES results to extract the dominant modes and their time coefficients. The POD analysis suggests that the high energy level found in the upper part of the tank results from an energy transfer from the coherent structures created downstream the two-finger baffle. Finally, the trailing vortices behind the impeller blades and the baffle were detected and visualized using Jeong and Hussain's technique. The results show that IBM-LES is a reliable tool for studying the unsteady characteristics of turbulent flow in agitated tanks with complex geometry.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 419-429"},"PeriodicalIF":3.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-09DOI: 10.1016/j.cherd.2025.02.003
Victor Osvaldo Vega-Muratalla, César Ramírez-Márquez, Luis Fernando Lira-Barragán, José María Ponce-Ortega
This paper presents a mathematical programming approach for designing and operating a sustainable supply chain for value-added lithium compounds. The model optimizes the utilization of lithium-rich brine and clay deposits using technologies tailored to market demands, aiming to maximize profitability while minimizing environmental impacts. By integrating a multi-objective framework, the study evaluates two scenarios: one with desalination units and one without them, highlighting environmental and economic trade-offs. Results demonstrate the critical role of desalination technologies in the lithium industry, enabling 92 % of the water in brine to be recovered and reducing freshwater consumption by 93 %, with only a 0.23 % reduction in profits. This methodology addresses dual objectives (economic profitability and environmental sustainability) offering a novel approach that aligns with global efforts for cleaner energy and sustainable lithium production. By bridging a significant research gap, the study integrates advanced optimization techniques with practical supply chain considerations, providing a robust solution for the evolving lithium market. This work underscores the importance of balancing profitability with sustainability, contributing to the development of environmentally responsible processes that support the transition to electromobility and a sustainable energy future.
{"title":"Optimal evaluation of brine desalination in the lithium supply chain: Balancing multi-objective strategies with global clean energy and electric vehicle initiatives","authors":"Victor Osvaldo Vega-Muratalla, César Ramírez-Márquez, Luis Fernando Lira-Barragán, José María Ponce-Ortega","doi":"10.1016/j.cherd.2025.02.003","DOIUrl":"10.1016/j.cherd.2025.02.003","url":null,"abstract":"<div><div>This paper presents a mathematical programming approach for designing and operating a sustainable supply chain for value-added lithium compounds. The model optimizes the utilization of lithium-rich brine and clay deposits using technologies tailored to market demands, aiming to maximize profitability while minimizing environmental impacts. By integrating a multi-objective framework, the study evaluates two scenarios: one with desalination units and one without them, highlighting environmental and economic trade-offs. Results demonstrate the critical role of desalination technologies in the lithium industry, enabling 92 % of the water in brine to be recovered and reducing freshwater consumption by 93 %, with only a 0.23 % reduction in profits. This methodology addresses dual objectives (economic profitability and environmental sustainability) offering a novel approach that aligns with global efforts for cleaner energy and sustainable lithium production. By bridging a significant research gap, the study integrates advanced optimization techniques with practical supply chain considerations, providing a robust solution for the evolving lithium market. This work underscores the importance of balancing profitability with sustainability, contributing to the development of environmentally responsible processes that support the transition to electromobility and a sustainable energy future.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 547-567"},"PeriodicalIF":3.7,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mismatch between the adsorption rate and the photocatalytic rate in the degradation of cyclohexane severely limits the degradation efficiency of cyclohexane. In order to improve the performance of adsorption-photocatalysis, this study significantly improved the photocatalytic performance by iron modification and application of uniform electric field. The kinetic equations of adsorption and photocatalysis were fitted by conducting cyclohexane degradation experiments, and then a theoretical model for rate adjustment was constructed. The results show that the surface iron doping in TiO2 has a high degree of dispersion; the Fe-TiO2 with ACF as the support has the best homogeneity at 180 ℃; and the Fe-modified TiO2 has a higher photocurrent, which is about four times the value of the unmodified TiO2. The pore structure of ACF remained good after the addition of Fe-TiO2; the optimum uniform electric field applied voltage was 2.0 V. In addition, the rate constants could be expressed in terms of the gas process variables, and the state points with the smallest difference between the adsorption rate and the photocatalytic rate were 68.58 %, 0.31 m/s and 42.44 ppm. This study provides a new avenue of research to improve the performance of adsorption photocatalysis in the degradation of cyclohexane.
{"title":"Study on the matching of adsorption rate and photocatalytic rate under electric field synergy to enhance the degradation performance of cyclohexane","authors":"Wei Xu , Cong Zhang , Jiahao Wan , Xinghui Zhang , Yuanda Cheng , Jiaqing Jin , Huimin Zhang , Chengchuan Duan , Yuhao Fang","doi":"10.1016/j.cherd.2025.02.006","DOIUrl":"10.1016/j.cherd.2025.02.006","url":null,"abstract":"<div><div>The mismatch between the adsorption rate and the photocatalytic rate in the degradation of cyclohexane severely limits the degradation efficiency of cyclohexane. In order to improve the performance of adsorption-photocatalysis, this study significantly improved the photocatalytic performance by iron modification and application of uniform electric field. The kinetic equations of adsorption and photocatalysis were fitted by conducting cyclohexane degradation experiments, and then a theoretical model for rate adjustment was constructed. The results show that the surface iron doping in TiO<sub>2</sub> has a high degree of dispersion; the Fe-TiO<sub>2</sub> with ACF as the support has the best homogeneity at 180 ℃; and the Fe-modified TiO<sub>2</sub> has a higher photocurrent, which is about four times the value of the unmodified TiO<sub>2</sub>. The pore structure of ACF remained good after the addition of Fe-TiO<sub>2</sub>; the optimum uniform electric field applied voltage was 2.0 V. In addition, the rate constants could be expressed in terms of the gas process variables, and the state points with the smallest difference between the adsorption rate and the photocatalytic rate were 68.58 %, 0.31 m/s and 42.44 ppm. This study provides a new avenue of research to improve the performance of adsorption photocatalysis in the degradation of cyclohexane.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 386-397"},"PeriodicalIF":3.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-06DOI: 10.1016/j.cherd.2025.01.045
Zhengyuan Song , Guogang Sun , Chenhao Xi , Shiwei Yuan , Gang Cao
The swirl plate is a simple, high-performance, and widely used demister structure. However, due to droplets re-entrainment, the separation efficiency of swirl plate demisters significantly decreases at high gas velocities, limiting their application. To address this issue, this paper has conducted an experimental study to investigate the performance of single swirl plate, two-stage series swirl plate demister and swirl plate demister with slits on cylinder wall. Results indicated that the two-stage structure could achieve a higher separation efficiency than the single swirl plate, while both the two structures failed to maintain high efficiency with rising gas velocity. Furthermore, compared to other structures, The demister with slits exhibited the ability to keep high efficiency at high gas velocities, and the gas velocity corresponding to high efficiency increased with length of the drainage slits. Especially, the demister that combined two-stage swirl plate and swirl plate with slits possesses the advantage of both two structures. At gas velocities ranging from 6 m/s to 12 m/s, The combined demister achieved an efficiency of at least 97 %, with a maximum reaching 98.8 %. Additionally, it is capable of completely removing droplets with diameters larger than 5.9μm within the gas velocity range of 6 m/s to 10 m/s. This design provides a solution to the challenge of maintaining high efficiency for swirl plate demisters at high superficial gas velocities.
{"title":"Enhancing the separation efficiency of the swirl plate demister operating at high gas velocities","authors":"Zhengyuan Song , Guogang Sun , Chenhao Xi , Shiwei Yuan , Gang Cao","doi":"10.1016/j.cherd.2025.01.045","DOIUrl":"10.1016/j.cherd.2025.01.045","url":null,"abstract":"<div><div>The swirl plate is a simple, high-performance, and widely used demister structure. However, due to droplets re-entrainment, the separation efficiency of swirl plate demisters significantly decreases at high gas velocities, limiting their application. To address this issue, this paper has conducted an experimental study to investigate the performance of single swirl plate, two-stage series swirl plate demister and swirl plate demister with slits on cylinder wall. Results indicated that the two-stage structure could achieve a higher separation efficiency than the single swirl plate, while both the two structures failed to maintain high efficiency with rising gas velocity. Furthermore, compared to other structures, The demister with slits exhibited the ability to keep high efficiency at high gas velocities, and the gas velocity corresponding to high efficiency increased with length of the drainage slits. Especially, the demister that combined two-stage swirl plate and swirl plate with slits possesses the advantage of both two structures. At gas velocities ranging from 6 m/s to 12 m/s, The combined demister achieved an efficiency of at least 97 %, with a maximum reaching 98.8 %. Additionally, it is capable of completely removing droplets with diameters larger than 5.9μm within the gas velocity range of 6 m/s to 10 m/s. This design provides a solution to the challenge of maintaining high efficiency for swirl plate demisters at high superficial gas velocities.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 522-530"},"PeriodicalIF":3.7,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-05DOI: 10.1016/j.cherd.2025.01.042
Ferdinand Breit, Christina Zipp, Christian Weibel, Erik von Harbou
The objective of this study was to evaluate the efficacy of a one-dimensional multifluid population balance model (1D-MPB) in predicting the axial variation of the bubble size distribution (BSD), gas phase velocity, and gas volume fraction in a bubble column. The bubble column was operated in either a semi-batch mode, without liquid feed, or a continuous mode, with co-current liquid and gas feed. The model’s predictions were compared with experimental data obtained through minimal invasive fiber optic needle probes. The experiments were carried out with different spargers and varying gas and liquid fluxes. The model parameters were previously determined in a different study. The findings indicate that the model accurately predicts the BSD, Sauter mean diameter and local gas volume fractions, particularly at medium gas fluxes in semi-batch mode. The application of a modified sparger model to predict inlet BSDs demonstrated potential, although limitations were observed at higher fluxes. In continuous co-current mode, the model (parameterized with data from semi-batch experiments), exhibited robust prediction performance without the need for recalibration, indicating the soundness of the underlying physical principles and the value of the method for scale-up. The mean absolute percentage error for the Sauter mean diameter and for the local gas volume fraction was about 10 %, depending on the mode of operation, type of sparger, fluid inlet flux and source of the inlet BSD (experimental or from the sparger model), and in many cases significantly less. Future work will focus on refining the turbulent energy dissipation model to enhance the model’s accuracy and applicability for industrial bubble column design and optimization.
{"title":"A quantitative evaluation of the prediction performance of a one-dimensional multifluid population balance model in continuous and semi-batch bubble columns","authors":"Ferdinand Breit, Christina Zipp, Christian Weibel, Erik von Harbou","doi":"10.1016/j.cherd.2025.01.042","DOIUrl":"10.1016/j.cherd.2025.01.042","url":null,"abstract":"<div><div>The objective of this study was to evaluate the efficacy of a one-dimensional multifluid population balance model (1D-MPB) in predicting the axial variation of the bubble size distribution (BSD), gas phase velocity, and gas volume fraction in a bubble column. The bubble column was operated in either a semi-batch mode, without liquid feed, or a continuous mode, with co-current liquid and gas feed. The model’s predictions were compared with experimental data obtained through minimal invasive fiber optic needle probes. The experiments were carried out with different spargers and varying gas and liquid fluxes. The model parameters were previously determined in a different study. The findings indicate that the model accurately predicts the BSD, Sauter mean diameter and local gas volume fractions, particularly at medium gas fluxes in semi-batch mode. The application of a modified sparger model to predict inlet BSDs demonstrated potential, although limitations were observed at higher fluxes. In continuous co-current mode, the model (parameterized with data from semi-batch experiments), exhibited robust prediction performance without the need for recalibration, indicating the soundness of the underlying physical principles and the value of the method for scale-up. The mean absolute percentage error for the Sauter mean diameter and for the local gas volume fraction was about 10 %, depending on the mode of operation, type of sparger, fluid inlet flux and source of the inlet BSD (experimental or from the sparger model), and in many cases significantly less. Future work will focus on refining the turbulent energy dissipation model to enhance the model’s accuracy and applicability for industrial bubble column design and optimization.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 430-442"},"PeriodicalIF":3.7,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-02-05DOI: 10.1016/j.cherd.2025.01.039
Michael Mansour , Dominique Thévenin
This study investigates the impact of different inducer designs on centrifugal pump performance during air–water two-phase flow pumping. A semi-open impeller with elliptical blades was tested with three configurations: no inducer, a traditional industrial inducer, and a novel optimized inducer. Experiments were conducted at a relevant rotational speed of 1450 rpm. The experimental analysis explores the performance for constant gas volume fraction, constant air flow rate, performance degradation, surging (flow instabilities), and two-phase flow regimes. High-speed cameras captured flow behavior to identify and categorize the flow regimes present during operation for each configuration. The results reveal that the industrial inducer could only provide limited performance improvements at part-load for the gas volume fraction range of 5%–6%. In contrary, the optimized inducer effectively delayed the sharp performance degradation to 7% gas volume fraction. Additionally, it provided almost constant performance near optimal flow conditions, showing a flat behavior up to 7% gas volume fraction. Performance improvements are still noticeable up to 11% air content. While the industrial inducer negatively advanced the onset of pump surging and increased its intensity, the optimized inducer strongly delays pump surging and maintains it at low intensity. The use of the industrial inducer leads to unstable curves for a wide range of flow rates for the performance with constant air flow rate at the inlet. However, the optimized inducer could improve that performance along the entire flow range, with almost no reduction near the optimal flow up to 100 L/min flow of air. The recorded flow regimes show the improved two-phase mixing and higher gas accumulation resistance when using the optimized inducer. Accordingly, the use of such an optimized inducer is highly recommended to keep robust two-phase pumping with minimal flow instabilities. the optimized inducer demonstrates remarkable effectiveness in enhancing pump performance. Based on our own experimental comparisons and findings, these improvements strongly outperform the capabilities of other traditional techniques commonly used to transport two-phase flows, including impeller modifications, tip clearance adjustments, and the use of a standard inducer.
{"title":"Optimized inducer design for transporting air–water two-phase flows in centrifugal pumps: Outperforming traditional inducers","authors":"Michael Mansour , Dominique Thévenin","doi":"10.1016/j.cherd.2025.01.039","DOIUrl":"10.1016/j.cherd.2025.01.039","url":null,"abstract":"<div><div>This study investigates the impact of different inducer designs on centrifugal pump performance during air–water two-phase flow pumping. A semi-open impeller with elliptical blades was tested with three configurations: no inducer, a traditional industrial inducer, and a novel optimized inducer. Experiments were conducted at a relevant rotational speed of 1450 rpm. The experimental analysis explores the performance for constant gas volume fraction, constant air flow rate, performance degradation, surging (flow instabilities), and two-phase flow regimes. High-speed cameras captured flow behavior to identify and categorize the flow regimes present during operation for each configuration. The results reveal that the industrial inducer could only provide limited performance improvements at part-load for the gas volume fraction range of 5%–6%. In contrary, the optimized inducer effectively delayed the sharp performance degradation to 7% gas volume fraction. Additionally, it provided almost constant performance near optimal flow conditions, showing a flat behavior up to 7% gas volume fraction. Performance improvements are still noticeable up to 11% air content. While the industrial inducer negatively advanced the onset of pump surging and increased its intensity, the optimized inducer strongly delays pump surging and maintains it at low intensity. The use of the industrial inducer leads to unstable curves for a wide range of flow rates for the performance with constant air flow rate at the inlet. However, the optimized inducer could improve that performance along the entire flow range, with almost no reduction near the optimal flow up to 100 L/min flow of air. The recorded flow regimes show the improved two-phase mixing and higher gas accumulation resistance when using the optimized inducer. Accordingly, the use of such an optimized inducer is highly recommended to keep robust two-phase pumping with minimal flow instabilities. the optimized inducer demonstrates remarkable effectiveness in enhancing pump performance. Based on our own experimental comparisons and findings, these improvements strongly outperform the capabilities of other traditional techniques commonly used to transport two-phase flows, including impeller modifications, tip clearance adjustments, and the use of a standard inducer.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"215 ","pages":"Pages 342-360"},"PeriodicalIF":3.7,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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