A reinforcement learning (RL) approach is developed in this work for nonlinear systems under stochastic uncertainty. A stochastic control Lyapunov function (SCLF) candidate is first constructed using neural networks (NNs) as an approximator to the value function, and then a control policy designed using this SCLF is developed to ensure the stability in probability of the stochastic nonlinear system. An RL algorithm is proposed for stochastic nonlinear systems to iteratively update the value function and control policy, driving them toward optimal values. We further extend its feasibility under the sample-and-hold implementation of control actions, and demonstrate its application to two chemical reactor examples to show its practical advantages and efficiency.
{"title":"Reinforcement learning for optimal control of stochastic nonlinear systems","authors":"Xinji Zhu, Yujia Wang, Zhe Wu","doi":"10.1002/aic.18840","DOIUrl":"https://doi.org/10.1002/aic.18840","url":null,"abstract":"A reinforcement learning (RL) approach is developed in this work for nonlinear systems under stochastic uncertainty. A stochastic control Lyapunov function (SCLF) candidate is first constructed using neural networks (NNs) as an approximator to the value function, and then a control policy designed using this SCLF is developed to ensure the stability in probability of the stochastic nonlinear system. An RL algorithm is proposed for stochastic nonlinear systems to iteratively update the value function and control policy, driving them toward optimal values. We further extend its feasibility under the sample-and-hold implementation of control actions, and demonstrate its application to two chemical reactor examples to show its practical advantages and efficiency.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"72 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723831","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}
Upgrading biomass-derived fatty acids through the H2-free and solvent-free catalytic deoxygenation process is both safe and eco-friendly. Herein, we used modified rice husk-derived biochar with ultra-high specific surface area and abundant surface groups as a support to design a homologous bimetallic site catalyst containing Ni single atoms (Ni1) and Ni nanoclusters (Nin), the synergy between which is dedicated to excellent catalytic performance. The designed catalyst, Ni1+n/A-bio-AC, demonstrated an impressive 89.8% selectivity for odd-numbered long-chain alkanes during the H2-free and solvent-free deoxygenation of stearic acid, with a turnover frequency value over 18 times higher than conventional Ni/AC. Multiple characterizations revealed the coexistence of Ni1 and Nin on the catalyst support. Experimental and theoretical calculations showed that Nin facilitates the adsorption of fatty acid substrates. While Ni1 serves as highly dispersed Lewis acid sites, enhancing the dehydrogenation of fatty alcohol intermediates during the in situ hydrodeoxygenation and lowering the decarboxylation pathway energy barriers via electronic synergy with Nin, thus remarkably boosting the catalytic deoxygenation activity. This work provides a novel Ni dual-site catalyst for developing biomass resource conversion technologies.
通过无h2和无溶剂催化脱氧工艺升级生物质衍生脂肪酸既安全又环保。本文以具有超高比表面积和丰富表面基团的改性稻壳生物炭为载体，设计了含Ni单原子（Ni1）和Ni纳米团簇（Nin）的同源双金属位点催化剂，二者协同作用具有优异的催化性能。所设计的催化剂Ni1+n/ a -bio-AC在硬脂酸无h2和无溶剂脱氧过程中对奇数长链烷烃的选择性高达89.8%，其转换频率值比传统Ni/AC高18倍以上。多次表征表明Ni1和Nin在催化剂载体上共存。实验和理论计算表明，Nin有利于脂肪酸底物的吸附。而Ni1作为高度分散的Lewis酸位点，通过与Nin的电子协同作用，增强了原位加氢脱氧过程中脂肪醇中间体的脱氢反应，降低了脱羧途径的能垒，从而显著提高了催化脱氧活性。本研究为开发生物质资源转化技术提供了一种新型镍双位点催化剂。
{"title":"Biochar assembled Ni atom-clusters for hydrogen-free and solvent-free deoxygenation of fatty acids","authors":"Bin Chen, Xingwen Cha, Xuexue Dong, Juanjuan Bian, Jiale Huang, Qingbiao Li, Xiaoqing Huang, Guowu Zhan","doi":"10.1002/aic.18821","DOIUrl":"https://doi.org/10.1002/aic.18821","url":null,"abstract":"Upgrading biomass-derived fatty acids through the H<sub>2</sub>-free and solvent-free catalytic deoxygenation process is both safe and eco-friendly. Herein, we used modified rice husk-derived biochar with ultra-high specific surface area and abundant surface groups as a support to design a homologous bimetallic site catalyst containing Ni single atoms (Ni<sub>1</sub>) and Ni nanoclusters (Ni<sub>n</sub>), the synergy between which is dedicated to excellent catalytic performance. The designed catalyst, Ni<sub>1+n</sub>/A-bio-AC, demonstrated an impressive 89.8% selectivity for odd-numbered long-chain alkanes during the H<sub>2</sub>-free and solvent-free deoxygenation of stearic acid, with a turnover frequency value over 18 times higher than conventional Ni/AC. Multiple characterizations revealed the coexistence of Ni<sub>1</sub> and Ni<sub>n</sub> on the catalyst support. Experimental and theoretical calculations showed that Ni<sub>n</sub> facilitates the adsorption of fatty acid substrates. While Ni<sub>1</sub> serves as highly dispersed Lewis acid sites, enhancing the dehydrogenation of fatty alcohol intermediates during the <i>in situ</i> hydrodeoxygenation and lowering the decarboxylation pathway energy barriers via electronic synergy with Ni<sub>n</sub>, thus remarkably boosting the catalytic deoxygenation activity. This work provides a novel Ni dual-site catalyst for developing biomass resource conversion technologies.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"36 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723834","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}
Ahmed Hamdy El-Kady, Md. Tanjin Amin, Faisal Khan, Mahmoud M. El-Halwagi
The offshore wind-integrated hydrogen production system is a novel approach to producing green energy carriers and chemicals. Even with the significant environmental benefits of this approach, there are major questions and concerns regarding its safety. Understanding better how operational parameters can promote safer operations is necessary. This paper overcomes key aspects of this gap by developing a novel method to quantify the influence of operational parameters on the formation of hazardous operational environments. Focus is given to the risks associated with gas crossover. The critical operational parameters (e.g., membrane thickness, cathodic pressure, supplied power, and H2/O2 recombination constant) have been identified, and their contribution to leading a potential accident scenario is assessed. The proposed method enables monitoring the unsafe operational space—the combination of parameters and their synergistic effect is causing a potential scenario. The proposed method would be an important tool that facilitates remote process control and safe operation.
{"title":"A novel methodology to determine the safe operating regime for an offshore wind-integrated electrolysis system","authors":"Ahmed Hamdy El-Kady, Md. Tanjin Amin, Faisal Khan, Mahmoud M. El-Halwagi","doi":"10.1002/aic.18807","DOIUrl":"https://doi.org/10.1002/aic.18807","url":null,"abstract":"The offshore wind-integrated hydrogen production system is a novel approach to producing green energy carriers and chemicals. Even with the significant environmental benefits of this approach, there are major questions and concerns regarding its safety. Understanding better how operational parameters can promote safer operations is necessary. This paper overcomes key aspects of this gap by developing a novel method to quantify the influence of operational parameters on the formation of hazardous operational environments. Focus is given to the risks associated with gas crossover. The critical operational parameters (e.g., membrane thickness, cathodic pressure, supplied power, and H<sub>2</sub>/O<sub>2</sub> recombination constant) have been identified, and their contribution to leading a potential accident scenario is assessed. The proposed method enables monitoring the unsafe operational space—the combination of parameters and their synergistic effect is causing a potential scenario. The proposed method would be an important tool that facilitates remote process control and safe operation.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"59 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723832","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}
Rachel E. Pollard, Nouha El Amri, Parker K. Lewis, Jacques Zacharie Thaddeus P. Ponce, Ashley Han, Xiuxian Li, Nathalie M. Pinkerton
Biomedical applications of colloidal nanocrystals (NC) have focused on nanoscale theranostics, that is, composite nanoparticles (CNP) that function as bioimaging probes while simultaneously delivering therapeutic payloads. Thus, there is a need for controlled CNP manufacturing methods that sufficiently decouple vehicle and cargo properties. Here, we investigate the assembly of poly(ethylene glycol)-b-poly(lactic acid) (PEG–PLA)-based CNPs loaded with PLA co-excipient, NCs of various sizes, and model drug molecule rubrene. We compare the established flash nanoprecipitation (FNP), a single-step method, with the emergent sequential nanoprecipitation (SNaP), a two-step method in which component addition can be temporally modulated. We find that using FNP to co-encapsulate cargo with mismatched assembly timescales yields poor CNP size control and nonuniform populations. In contrast, by delaying the CNP stabilizer addition by a few milliseconds via SNaP, we enable CNP size control, a 3-fold increase in cargo uniformity, and a 10-fold increase in co-encapsulation efficiency with rubrene.
{"title":"Sequential nanoprecipitation for theranostics: Resolving assembly timescale mismatch in composite nanoparticle synthesis","authors":"Rachel E. Pollard, Nouha El Amri, Parker K. Lewis, Jacques Zacharie Thaddeus P. Ponce, Ashley Han, Xiuxian Li, Nathalie M. Pinkerton","doi":"10.1002/aic.18817","DOIUrl":"https://doi.org/10.1002/aic.18817","url":null,"abstract":"Biomedical applications of colloidal nanocrystals (NC) have focused on nanoscale theranostics, that is, composite nanoparticles (CNP) that function as bioimaging probes while simultaneously delivering therapeutic payloads. Thus, there is a need for controlled CNP manufacturing methods that sufficiently decouple vehicle and cargo properties. Here, we investigate the assembly of poly(ethylene glycol)-b-poly(lactic acid) (PEG–PLA)-based CNPs loaded with PLA co-excipient, NCs of various sizes, and model drug molecule rubrene. We compare the established flash nanoprecipitation (FNP), a single-step method, with the emergent sequential nanoprecipitation (SNaP), a two-step method in which component addition can be temporally modulated. We find that using FNP to co-encapsulate cargo with mismatched assembly timescales yields poor CNP size control and nonuniform populations. In contrast, by delaying the CNP stabilizer addition by a few milliseconds via SNaP, we enable CNP size control, a 3-fold increase in cargo uniformity, and a 10-fold increase in co-encapsulation efficiency with rubrene.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"49 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703508","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}
Min Yu, Guangji Zhang, Kai Li, Feiying Tang, Liqiang Wang, You-Nian Liu
It is highly desired but still challenging to engineer single-atom catalysts featuring an M–N–C configuration for efficient catalytic hydrogenation. Herein, Ni nanoparticles (Ni NPs) modified Ni–N–C (termed as Ni1+NPs/NSPC) were fabricated to demonstrate the feasibility of enhancing the catalytic hydrogenation performance of M–N–C by introducing metallic NPs sites. NiNPs sites and Ni1 sites displayed a synergistic effect: NiNPs promote the dissociation of H2 in a homolytic manner with a lower barrier energy than the heterolytic one that occurred on Ni1 sites, whereas Ni1 could burden the activation of substrates. The active H atoms generated at NiNPs migrate to Ni1 sites to complete hydrogenation. Consequently, Ni1+NPs/NSPC catalysts were empowered with excellent hydrogenation performance; they can be applied to a series of hydrogenation substrates (e.g., nitro compounds, furfural, quinine, and cyanophenyl) affording high conversion (95.1%–99.9%) and selectivity (96.8%–99.9%).
设计具有M-N-C结构的单原子催化剂用于高效的催化加氢是非常需要的，但仍然具有挑战性。本文制备了Ni纳米粒子（Ni NPs）修饰Ni - n - c（称为Ni1+NPs/NSPC），以证明通过引入金属NPs位点提高M-N-C催化加氢性能的可行性。NiNPs位点和Ni1位点表现出协同效应：NiNPs促进H2的均解离解，其势垒能低于Ni1位点的异解离解，而Ni1则会加重底物的活化。在NiNPs上产生的活性氢原子迁移到Ni1位点完成氢化。结果表明，Ni1+NPs/NSPC催化剂具有优异的加氢性能；它们可以应用于一系列加氢底物（例如，硝基化合物，糠醛，奎宁和氰苯），提供高转化率（95.1%-99.9%）和选择性（96.8%-99.9%）。
{"title":"Ni nanoparticles decorated Ni–N–C catalyst: Dual-site synergy for enhanced catalytic hydrogenation","authors":"Min Yu, Guangji Zhang, Kai Li, Feiying Tang, Liqiang Wang, You-Nian Liu","doi":"10.1002/aic.18830","DOIUrl":"https://doi.org/10.1002/aic.18830","url":null,"abstract":"It is highly desired but still challenging to engineer single-atom catalysts featuring an M–N–C configuration for efficient catalytic hydrogenation. Herein, Ni nanoparticles (Ni NPs) modified Ni–N–C (termed as Ni<sub>1+NPs</sub>/NSPC) were fabricated to demonstrate the feasibility of enhancing the catalytic hydrogenation performance of M–N–C by introducing metallic NPs sites. Ni<sub>NPs</sub> sites and Ni<sub>1</sub> sites displayed a synergistic effect: Ni<sub>NPs</sub> promote the dissociation of H<sub>2</sub> in a homolytic manner with a lower barrier energy than the heterolytic one that occurred on Ni<sub>1</sub> sites, whereas Ni<sub>1</sub> could burden the activation of substrates. The active H atoms generated at Ni<sub>NPs</sub> migrate to Ni<sub>1</sub> sites to complete hydrogenation. Consequently, Ni<sub>1+NPs</sub>/NSPC catalysts were empowered with excellent hydrogenation performance; they can be applied to a series of hydrogenation substrates (e.g., nitro compounds, furfural, quinine, and cyanophenyl) affording high conversion (95.1%–99.9%) and selectivity (96.8%–99.9%).","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"21 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703591","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}
In this work, an investigation of the transition from fixed to fluidized state of initially homogeneous binary-solid mixtures due to an upward liquid flux was carried out. Like for analogous gas systems, it was confirmed that the full transition occurs over a range of fluid velocities, from the initial to the final fluidization velocity. Based on fluid dynamic equilibrium considerations, we proposed a simple model that quantitatively predicts the different bed configurations as a function of fluid velocity. Thanks to the model, all the mixtures were categorized into four regions, which determined their behavior during the transition process. Extensive experimental investigations supported model predictions, offering insights that had not been reported in previous studies.
{"title":"The transition from the fixed to the fluidized state of well-mixed binary-solid mixtures in a liquid upflow","authors":"Renzo Di Felice, Filippo Marchelli","doi":"10.1002/aic.18831","DOIUrl":"https://doi.org/10.1002/aic.18831","url":null,"abstract":"In this work, an investigation of the transition from fixed to fluidized state of initially homogeneous binary-solid mixtures due to an upward liquid flux was carried out. Like for analogous gas systems, it was confirmed that the full transition occurs over a range of fluid velocities, from the initial to the final fluidization velocity. Based on fluid dynamic equilibrium considerations, we proposed a simple model that quantitatively predicts the different bed configurations as a function of fluid velocity. Thanks to the model, all the mixtures were categorized into four regions, which determined their behavior during the transition process. Extensive experimental investigations supported model predictions, offering insights that had not been reported in previous studies.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"62 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695088","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}
To accelerate the applied research pace for the continuous synthesis of high value-added rufinamide aiming at industrial applications, this work proposes a two-stage adjustable robust optimization framework with mixed-integer recourse to identify the optimal one from more than 500 possible alternative continuous synthetic routes. The overall rufinamide manufacturing process can be divided into three major processing steps, namely the halogenation of the precursor, azidation, and cycloaddition. A mixed-integer nonlinear programming (MINLP) model is formulated under multiple uncertainties. Considering the numbering-up of micro-reactors for adjusting the production capacity, the mixed-integer recourse leads to an intractable optimization problem. Hence, a tailored solution strategy based on the nested column-and-constraint generation (C&CG) is established to efficiently solve the resulting adjustable robust counterpart. Compared to the deterministic model, the benefits of implementing adjustable robust optimization (ARO) are fully demonstrated by evaluating the objective among sampled scenarios, where a cost reduction of up to 3% can be achieved.
{"title":"Adjustable robust superstructure optimization with mixed-integer recourse for the continuous rufinamide manufacturing","authors":"Taoyu Qiu, Wenhui Yang, Congqin Ge, Lifeng Zhang, Zhihong Yuan","doi":"10.1002/aic.18832","DOIUrl":"https://doi.org/10.1002/aic.18832","url":null,"abstract":"To accelerate the applied research pace for the continuous synthesis of high value-added rufinamide aiming at industrial applications, this work proposes a two-stage adjustable robust optimization framework with mixed-integer recourse to identify the optimal one from more than 500 possible alternative continuous synthetic routes. The overall rufinamide manufacturing process can be divided into three major processing steps, namely the halogenation of the precursor, azidation, and cycloaddition. A mixed-integer nonlinear programming (MINLP) model is formulated under multiple uncertainties. Considering the numbering-up of micro-reactors for adjusting the production capacity, the mixed-integer recourse leads to an intractable optimization problem. Hence, a tailored solution strategy based on the nested column-and-constraint generation (C&CG) is established to efficiently solve the resulting adjustable robust counterpart. Compared to the deterministic model, the benefits of implementing adjustable robust optimization (ARO) are fully demonstrated by evaluating the objective among sampled scenarios, where a cost reduction of up to 3% can be achieved.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"96 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695110","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}
Regulating the concentration of low-coordinated oxygen species on certain exposed crystal facets of oxides still remains a challenge. Herein, we developed a facile facet-engineering method to construct regulable ratios of (100), (110), and (111) facets on the MgO by modulating the surface curvature. As revealed by in situ CO2 diffused reflectance infrared Fourier transform spectroscopy and kinetic studies, it is found that MgO with a high density of active facets (i.e., [111] and [110] facets) exhibits ca. two times higher CO2 adsorption capacity. Based on the results of the density functional theory calculation, the activation of CO2 by MgO is enhanced with the increase in low-coordinated oxygen on active facets. Notably, the trapezoidal MgO with high-density active facets shows an increase in propylene epoxide conversion by ca. 33% without halogens, while maintaining a high propylene carbonate selectivity of 97.9%. This work will pave the way for the rational design of high-performance oxide catalysts by the facet-regulating strategy.
{"title":"Facet-regulated local coordination of oxygen species on MgO for efficient cycloaddition of CO2 with propylene oxide","authors":"Ranfei Fu, Juncong Yuan, Yaqian Li, Zeping Wang, Jianlin Cao, Jiaxu Wang, Jiali Dai, Baoyang Zhang, De Chen, Chaohe Yang, Xiang Feng","doi":"10.1002/aic.18826","DOIUrl":"https://doi.org/10.1002/aic.18826","url":null,"abstract":"Regulating the concentration of low-coordinated oxygen species on certain exposed crystal facets of oxides still remains a challenge. Herein, we developed a facile facet-engineering method to construct regulable ratios of (100), (110), and (111) facets on the MgO by modulating the surface curvature. As revealed by <i>in situ</i> CO<sub>2</sub> diffused reflectance infrared Fourier transform spectroscopy and kinetic studies, it is found that MgO with a high density of active facets (i.e., [111] and [110] facets) exhibits ca. two times higher CO<sub>2</sub> adsorption capacity. Based on the results of the density functional theory calculation, the activation of CO<sub>2</sub> by MgO is enhanced with the increase in low-coordinated oxygen on active facets. Notably, the trapezoidal MgO with high-density active facets shows an increase in propylene epoxide conversion by ca. 33% without halogens, while maintaining a high propylene carbonate selectivity of 97.9%. This work will pave the way for the rational design of high-performance oxide catalysts by the facet-regulating strategy.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695112","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}
In this study, an apparent reaction kinetic model is established for high-gravity intensified Fe-MnOX/AC-catalyzed ozonation of phenol in a rotating packed bed (PRB). It is found that this model can accurately predict the removal rate of phenol, with the deviations between experimental and theoretical values being less than 8%. The rate constants of the direct reaction of ozone and the indirect reaction of ·OH and the parameter RCT are obtained, based on which their contributions to the removal of phenol can be more accurately estimated. The contribution factor is 77.5% for the direct reaction (fO3) and 22.5% for the indirect reaction (f•OH), respectively. This study provides a feasible method to establish the kinetic model for heterogeneous catalytic ozonation of organic matter, as well as new insights into the direct and indirect reaction mechanism of ozone with phenol.
{"title":"A kinetic model for high-gravity intensified Fe-MnOX/AC-catalyzed ozonation of phenol: Direct and indirect reaction","authors":"Zhiwei Zhao, Youzhi Liu, Weizhou Jiao","doi":"10.1002/aic.18812","DOIUrl":"https://doi.org/10.1002/aic.18812","url":null,"abstract":"In this study, an apparent reaction kinetic model is established for high-gravity intensified Fe-MnO<sub>X</sub>/AC-catalyzed ozonation of phenol in a rotating packed bed (PRB). It is found that this model can accurately predict the removal rate of phenol, with the deviations between experimental and theoretical values being less than 8%. The rate constants of the direct reaction of ozone and the indirect reaction of ·OH and the parameter <i>R</i><sub>CT</sub> are obtained, based on which their contributions to the removal of phenol can be more accurately estimated. The contribution factor is 77.5% for the direct reaction (<i>f</i><sub><i>O</i>3</sub>) and 22.5% for the indirect reaction (<i>f</i><sub><i>•OH</i></sub>), respectively. This study provides a feasible method to establish the kinetic model for heterogeneous catalytic ozonation of organic matter, as well as new insights into the direct and indirect reaction mechanism of ozone with phenol.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"40 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695111","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}
High-efficiency reduction of the microbubble size is important for bubble-based microflow processes but has hitherto required high-energy-consumption methods. This study designed a new T-junction microchannel with a flexible interaction region exhibiting apparent superiority in producing smaller bubbles with high energy-utilization efficiency, and for the first time breaks the limitation of the flow pattern in the ordinary T-junction microchannel. The results indicate that under the given two-phase working conditions, the microbubble size was greatly reduced in the new T-junction microchannel compared to that in the ordinary one. The microbubble formation mechanism in the new microdevice is analyzed via a simulated liquid velocity field. Importantly, the bubbly flow pattern appeared rapidly under a higher gas flow rate, which is totally opposite to the expectations in the ordinary T-junction. Finally, via interface analysis, the importance of the gas velocity on the viscous shearing force was clarified, and a new bubble size-prediction model was developed.
{"title":"Remarkable reduction of microbubble size by constructing a flexible interaction region in a T-junction microchannel","authors":"Lin Sheng, Junjie Wang, Jian Deng, Guangsheng Luo","doi":"10.1002/aic.18834","DOIUrl":"https://doi.org/10.1002/aic.18834","url":null,"abstract":"High-efficiency reduction of the microbubble size is important for bubble-based microflow processes but has hitherto required high-energy-consumption methods. This study designed a new T-junction microchannel with a flexible interaction region exhibiting apparent superiority in producing smaller bubbles with high energy-utilization efficiency, and for the first time breaks the limitation of the flow pattern in the ordinary T-junction microchannel. The results indicate that under the given two-phase working conditions, the microbubble size was greatly reduced in the new T-junction microchannel compared to that in the ordinary one. The microbubble formation mechanism in the new microdevice is analyzed via a simulated liquid velocity field. Importantly, the bubbly flow pattern appeared rapidly under a higher gas flow rate, which is totally opposite to the expectations in the ordinary T-junction. Finally, via interface analysis, the importance of the gas velocity on the viscous shearing force was clarified, and a new bubble size-prediction model was developed.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"57 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678316","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}
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