The recent advancement in mechanically and chemically robust membranes has led to the capabilities of both reverse osmosis (RO) and pervaporation (PV) for separation of water/organic solvent and organic solvent mixtures. However, their performances are evaluated in different permeation formulas. To address this, we have conducted an analysis using a unified parameter: activity-based permeance. The present study evaluated RO and PV using the same organosilica membrane for the separation of both non-aqueous solvents (methanol/ethanol, methanol/iso-propanol [IPA], and methanol/dimethyl carbonate) and organic solvent-aqueous mixtures (including water with methanol, ethanol, IPA, tert-butanol, and glucose), at concentrations ranging from 0% to 100%. With the use of activity-based permeance, we achieved a consistent evaluation of both PV and RO processes. Moreover, this approach provides prediction of separation performance even in RO and PV.
{"title":"Analysis of reverse osmosis and pervaporation using activity-based permeance: Aqueous and nonaqueous systems","authors":"Norihiro Moriyama, Shun-ichi Shiozaki, Hiroki Nagasawa, Masakoto Kanezashi, Toshinori Tsuru","doi":"10.1002/aic.18585","DOIUrl":"https://doi.org/10.1002/aic.18585","url":null,"abstract":"The recent advancement in mechanically and chemically robust membranes has led to the capabilities of both reverse osmosis (RO) and pervaporation (PV) for separation of water/organic solvent and organic solvent mixtures. However, their performances are evaluated in different permeation formulas. To address this, we have conducted an analysis using a unified parameter: activity-based permeance. The present study evaluated RO and PV using the same organosilica membrane for the separation of both non-aqueous solvents (methanol/ethanol, methanol/iso-propanol [IPA], and methanol/dimethyl carbonate) and organic solvent-aqueous mixtures (including water with methanol, ethanol, IPA, tert-butanol, and glucose), at concentrations ranging from 0% to 100%. With the use of activity-based permeance, we achieved a consistent evaluation of both PV and RO processes. Moreover, this approach provides prediction of separation performance even in RO and PV.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"138 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142142819","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}
William Collins Keith, Farnaz Hemmati, Ravi Sureshbhai Vaghasiya, Farshad Amiri, Panagiotis Mistriotis
In vivo, migrating cells often encounter microenvironments that impose spatial constraints, leading to cell and nuclear deformation. As confinement-induced DNA damage has been linked to the accumulation of reactive oxygen species (ROS), we sought to investigate the impact of oxidative stress on cell behavior within confined spaces. Using microchannel devices that enable control of the degree and duration of cell confinement, we demonstrate that confined migration increases ROS levels in both HT-1080 fibrosarcoma cells and human dermal fibroblasts. Treatment with the antioxidant N-Acetyl-L-cysteine (NAC) counteracts confinement-induced ROS accumulation, suppressing p53 activation and supporting cell survival in both cell lines. This intervention preferentially reduces dorsal perinuclear actin fibers in confined cancer cells. Loss of these fibers is associated with reduced nuclear rupture frequency and increased confined migration speed. Collectively, this work provides insights into the differential effects of ROS on cancerous and non-cancerous cells and suggests that antioxidants may support tumor progression.
{"title":"Differential effects of confinement-induced reactive oxygen species accumulation on highly motile cancerous and non-cancerous cells","authors":"William Collins Keith, Farnaz Hemmati, Ravi Sureshbhai Vaghasiya, Farshad Amiri, Panagiotis Mistriotis","doi":"10.1002/aic.18598","DOIUrl":"10.1002/aic.18598","url":null,"abstract":"<p>In vivo, migrating cells often encounter microenvironments that impose spatial constraints, leading to cell and nuclear deformation. As confinement-induced DNA damage has been linked to the accumulation of reactive oxygen species (ROS), we sought to investigate the impact of oxidative stress on cell behavior within confined spaces. Using microchannel devices that enable control of the degree and duration of cell confinement, we demonstrate that confined migration increases ROS levels in both HT-1080 fibrosarcoma cells and human dermal fibroblasts. Treatment with the antioxidant <i>N</i>-Acetyl-L-cysteine (NAC) counteracts confinement-induced ROS accumulation, suppressing p53 activation and supporting cell survival in both cell lines. This intervention preferentially reduces dorsal perinuclear actin fibers in confined cancer cells. Loss of these fibers is associated with reduced nuclear rupture frequency and increased confined migration speed. Collectively, this work provides insights into the differential effects of ROS on cancerous and non-cancerous cells and suggests that antioxidants may support tumor progression.</p>","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"70 12","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131055","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}
An optimal process plant layout needs to ensure that the associated piping and land costs are minimized, while the overall safety is maximized. Although various approaches to optimizing plant layout exists in the literature, none considers the essential need for simultaneous compliance with local risk regulations. Employing mixed-integer nonlinear programming, this article presents a methodology to enable design of layout of a major hazard plant, while simultaneously achieving conformity with both applicable individual and societal risk acceptance criteria. The algorithm is applied to a model plant which poses hazards of toxic gas releases, fires, and explosions. Additional risks of domino effects due to fires and explosions are also incorporated. The results of the article suggest that the approach can be employed to automate any plant layout optimization exercise while ensuring regulatory compliance concurrently. The proposed approach can help substitute the iterative, manual process that is presently applied in practice.
{"title":"Optimization of process plant layout using critical risk metrics","authors":"Abhi Manjunath Dasari, Nisarg Ashish Kothari, Gaurav Reddy, Kushal Dhinoja, Sandip Roy","doi":"10.1002/aic.18596","DOIUrl":"https://doi.org/10.1002/aic.18596","url":null,"abstract":"An optimal process plant layout needs to ensure that the associated piping and land costs are minimized, while the overall safety is maximized. Although various approaches to optimizing plant layout exists in the literature, none considers the essential need for simultaneous compliance with local risk regulations. Employing mixed-integer nonlinear programming, this article presents a methodology to enable design of layout of a major hazard plant, while simultaneously achieving conformity with both applicable individual and societal risk acceptance criteria. The algorithm is applied to a model plant which poses hazards of toxic gas releases, fires, and explosions. Additional risks of domino effects due to fires and explosions are also incorporated. The results of the article suggest that the approach can be employed to automate any plant layout optimization exercise while ensuring regulatory compliance concurrently. The proposed approach can help substitute the iterative, manual process that is presently applied in practice.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"42 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131054","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}
Cedric Devos, Saikat Mukherjee, Pavan Inguva, Shalini Singh, Yi Wei, Sandip Mondal, Huiwen Yu, George Barbastathis, Torsten Stelzer, Richard D. Braatz, Allan S. Myerson
Optimal control over fast chemical processes hinges on the achievement of rapid and effective mixing. Impinging jet mixers are a unique class of passive mixing devices renowned for their exceptional ability to achieve rapid mixing at micro‐length scales, whilst offering the possibility of a high throughput. Comprising of two co‐linear jets flowing in opposite directions and colliding with each other within a small (usually confined) volume, these devices effectively intensify various mixing‐controlled processes in a reproducible manner. Impinging jet mixers find extensive use in both the chemical and pharmaceutical industry for a plethora of applications, such as reaction injection molding and precipitation processes. This review provides an overview of research related to impinging jet mixers, with an emphasis on the mixing characteristics and the influence of design and process parameters on the mixing performance. Lastly, specific applications for which these devices are exceptionally suited are discussed.
{"title":"Impinging jet mixers: A review of their mixing characteristics, performance considerations, and applications","authors":"Cedric Devos, Saikat Mukherjee, Pavan Inguva, Shalini Singh, Yi Wei, Sandip Mondal, Huiwen Yu, George Barbastathis, Torsten Stelzer, Richard D. Braatz, Allan S. Myerson","doi":"10.1002/aic.18595","DOIUrl":"https://doi.org/10.1002/aic.18595","url":null,"abstract":"Optimal control over fast chemical processes hinges on the achievement of rapid and effective mixing. Impinging jet mixers are a unique class of passive mixing devices renowned for their exceptional ability to achieve rapid mixing at micro‐length scales, whilst offering the possibility of a high throughput. Comprising of two co‐linear jets flowing in opposite directions and colliding with each other within a small (usually confined) volume, these devices effectively intensify various mixing‐controlled processes in a reproducible manner. Impinging jet mixers find extensive use in both the chemical and pharmaceutical industry for a plethora of applications, such as reaction injection molding and precipitation processes. This review provides an overview of research related to impinging jet mixers, with an emphasis on the mixing characteristics and the influence of design and process parameters on the mixing performance. Lastly, specific applications for which these devices are exceptionally suited are discussed.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"101 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142138236","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}
Guangxia Jin, Yuxue Wu, Jiarong Sang, Feng Wei, Ning Kang
This work reported the application of a twin‐column recycling chromatography system for the separation of three minor impurities in crude aloe‐emodin. The whole process went through three steps, each using a different mobile phase to separate corresponding impurity, which were integrated and automatically operated in a single device. Despite these impurities peaked closely in high‐performance liquid chromatography, they were successfully purified to a content exceeding 97%. In addition, the lab‐scale separation could reach the yields at the mg‐level. The high efficacy should be mainly attributed to the introduction of a small step solvent gradient between the upstream and downstream columns, which helped to counterbalance the band broadening. This report suggested that such an automated chromatographic system could provide fast and accurate separation of multiple impurities, allow the process of high‐throughput samples, and reduce the time required for purification and recovery of minor impurities in drugs.
{"title":"Three‐step integrated process for isolation and purification of impurities in drug substance by recycling chromatography","authors":"Guangxia Jin, Yuxue Wu, Jiarong Sang, Feng Wei, Ning Kang","doi":"10.1002/aic.18597","DOIUrl":"https://doi.org/10.1002/aic.18597","url":null,"abstract":"This work reported the application of a twin‐column recycling chromatography system for the separation of three minor impurities in crude aloe‐emodin. The whole process went through three steps, each using a different mobile phase to separate corresponding impurity, which were integrated and automatically operated in a single device. Despite these impurities peaked closely in high‐performance liquid chromatography, they were successfully purified to a content exceeding 97%. In addition, the lab‐scale separation could reach the yields at the mg‐level. The high efficacy should be mainly attributed to the introduction of a small step solvent gradient between the upstream and downstream columns, which helped to counterbalance the band broadening. This report suggested that such an automated chromatographic system could provide fast and accurate separation of multiple impurities, allow the process of high‐throughput samples, and reduce the time required for purification and recovery of minor impurities in drugs.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130814","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}
Weitong Pan, Longfei Tang, Yunfei Gao, Lu Ding, Zhenghua Dai, Xueli Chen, Fuchen Wang
The flow distribution issue is of significance to the fuel cell stack performance and durability, which herein is studied from a theoretical and practical level. The manifold flow fundamentals are clarified and the pressure‐reconstruction‐based principle to regulate flow distribution is revealed. The prerequisite and corequisite lie in the ratio of pressure drop between headers and the entire manifold, and the pressure recovery in the inlet header. Accordingly, a step‐by‐step manifold design methodology is proposed and further quantified by detailed and organized simulations. A desirable effect on flow uniformity is validated in large‐scale stacks consisting of 300 and 400 cells, and the values of flow uniformity index represented by coefficient of variation (CV) are 3.32% and 2.95%, respectively. Moreover, a novel wedge‐shaped layout of the intake header is proposed for further optimization. The corresponding CV values have notably declined to 1.36% and 1.29%, nearly 60% lower than the conventional rectangular counterparts.
{"title":"A CFD‐based manifold design methodology for large‐scale PEM fuel cell stacks","authors":"Weitong Pan, Longfei Tang, Yunfei Gao, Lu Ding, Zhenghua Dai, Xueli Chen, Fuchen Wang","doi":"10.1002/aic.18601","DOIUrl":"https://doi.org/10.1002/aic.18601","url":null,"abstract":"The flow distribution issue is of significance to the fuel cell stack performance and durability, which herein is studied from a theoretical and practical level. The manifold flow fundamentals are clarified and the pressure‐reconstruction‐based principle to regulate flow distribution is revealed. The prerequisite and corequisite lie in the ratio of pressure drop between headers and the entire manifold, and the pressure recovery in the inlet header. Accordingly, a step‐by‐step manifold design methodology is proposed and further quantified by detailed and organized simulations. A desirable effect on flow uniformity is validated in large‐scale stacks consisting of 300 and 400 cells, and the values of flow uniformity index represented by coefficient of variation (<jats:italic>CV</jats:italic>) are 3.32% and 2.95%, respectively. Moreover, a novel wedge‐shaped layout of the intake header is proposed for further optimization. The corresponding <jats:italic>CV</jats:italic> values have notably declined to 1.36% and 1.29%, nearly 60% lower than the conventional rectangular counterparts.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123578","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}
Xinhui Tang, Chenchen Zhou, Hongxin Su, Yi Cao, Shuang‐Hua Yang
Numerous nonlinear distributed parameter systems (DPSs) operate within an extensive range due to process uncertainties. Their spatial distribution characteristic, combined with nonlinearity and uncertainty, poses challenges in optimal operation under two‐step real‐time optimization (RTO) and economic model predictive control (EMPC). Both methods necessitate substantial computational power for prompt online reoptimization. Recent local distributed parameter self‐optimizing control (DPSOC) achieves optimality without repetitive optimization. However, its effectiveness is confined to a narrow range around a nominal operation. Here, globalized DPSOC is introduced to surmount the limitation of the local DPSOC. A global loss functional concerning controlled variables (CVs) is formulated using linear operators and Fubini's theorem. Minimizing the loss with a numerical optimization procedure yields CVs exhibiting global optimality. Maintaining these CVs at constants ensures such a process has a minimal average loss in a large operating space. The effectiveness of the proposed method is substantiated through a transport reaction simulation.
{"title":"Globalization of distributed parameter self‐optimizing control","authors":"Xinhui Tang, Chenchen Zhou, Hongxin Su, Yi Cao, Shuang‐Hua Yang","doi":"10.1002/aic.18594","DOIUrl":"https://doi.org/10.1002/aic.18594","url":null,"abstract":"Numerous nonlinear distributed parameter systems (DPSs) operate within an extensive range due to process uncertainties. Their spatial distribution characteristic, combined with nonlinearity and uncertainty, poses challenges in optimal operation under two‐step real‐time optimization (RTO) and economic model predictive control (EMPC). Both methods necessitate substantial computational power for prompt online reoptimization. Recent local distributed parameter self‐optimizing control (DPSOC) achieves optimality without repetitive optimization. However, its effectiveness is confined to a narrow range around a nominal operation. Here, globalized DPSOC is introduced to surmount the limitation of the local DPSOC. A global loss functional concerning controlled variables (CVs) is formulated using linear operators and Fubini's theorem. Minimizing the loss with a numerical optimization procedure yields CVs exhibiting global optimality. Maintaining these CVs at constants ensures such a process has a minimal average loss in a large operating space. The effectiveness of the proposed method is substantiated through a transport reaction simulation.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"48 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123583","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}
Guoping Hu, Yalou Guo, Jinbiao Luo, Gongkui Xiao, Roman Weh, Kevin Gang Li, Tao Qi, Paul A. Webley, Eric F. May
Dual reflux pressure swing adsorption (DR‐PSA) has been regarded as a state‐of‐the‐art adsorption‐based process which can simultaneously obtain two streams of pure product gases with a narrow pressure window. However, the DR‐PSA has not yet been reported in industrial applications. Herein, a DR‐PSA and a heavy‐purge pressure vacuum swing adsorption (HP‐PVSA) were numerically investigated for the enrichment of 1%, 8% and 15% CH4 from N2 gas mixtures in pilot‐scale. Key separation indicators such as purity, recovery and energy cost of the two cycles were compared to analyze the limitations of the DR‐PSA process while scaling‐up. This study reveals the impact of heavy to feed (H/F) ratios on purity and recovery for both cycles and analyses the energy consumption of each process. For feed gas with 15% CH4, while DR‐PSA can achieve a slightly better purity and recovery (88.3% and 88.3%, respectively) compared to HP‐PVSA (87.5% and 80.3%, respectively), it also involves an order of magnitude higher energy consumption (181.6 versus 24.6 kJ/mol CH4 captured). DR‐PSA shows significantly superior performance than HP‐PVSA when the CH4 content in the raw feed gas is low. Under the investigated operating conditions, HP‐PVSA can only enrich 1% CH4 to 10% with 78.7% recovery while DR‐PSA can obtain 75.3% purity and 77.3% recovery. Results indicate that DR‐PSA exhibits superiority in enrichment of dilute gas, however, its high energy consumption, high capital expenditures and limitations in processing high throughput are the chief reasons hindering its industrial application.
{"title":"A numerical comparison of heavy‐purge and dual‐reflux strategies in pressure swing adsorption for methane enrichment","authors":"Guoping Hu, Yalou Guo, Jinbiao Luo, Gongkui Xiao, Roman Weh, Kevin Gang Li, Tao Qi, Paul A. Webley, Eric F. May","doi":"10.1002/aic.18573","DOIUrl":"https://doi.org/10.1002/aic.18573","url":null,"abstract":"Dual reflux pressure swing adsorption (DR‐PSA) has been regarded as a state‐of‐the‐art adsorption‐based process which can simultaneously obtain two streams of pure product gases with a narrow pressure window. However, the DR‐PSA has not yet been reported in industrial applications. Herein, a DR‐PSA and a heavy‐purge pressure vacuum swing adsorption (HP‐PVSA) were numerically investigated for the enrichment of 1%, 8% and 15% CH<jats:sub>4</jats:sub> from N<jats:sub>2</jats:sub> gas mixtures in pilot‐scale. Key separation indicators such as purity, recovery and energy cost of the two cycles were compared to analyze the limitations of the DR‐PSA process while scaling‐up. This study reveals the impact of heavy to feed (H/F) ratios on purity and recovery for both cycles and analyses the energy consumption of each process. For feed gas with 15% CH<jats:sub>4</jats:sub>, while DR‐PSA can achieve a slightly better purity and recovery (88.3% and 88.3%, respectively) compared to HP‐PVSA (87.5% and 80.3%, respectively), it also involves an order of magnitude higher energy consumption (181.6 versus 24.6 kJ/mol CH<jats:sub>4</jats:sub> captured). DR‐PSA shows significantly superior performance than HP‐PVSA when the CH<jats:sub>4</jats:sub> content in the raw feed gas is low. Under the investigated operating conditions, HP‐PVSA can only enrich 1% CH<jats:sub>4</jats:sub> to 10% with 78.7% recovery while DR‐PSA can obtain 75.3% purity and 77.3% recovery. Results indicate that DR‐PSA exhibits superiority in enrichment of dilute gas, however, its high energy consumption, high capital expenditures and limitations in processing high throughput are the chief reasons hindering its industrial application.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"24 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142101477","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}
Simone Reynoso‐Donzelli, Luis Alberto Ricardez‐Sandoval
This study introduces two novel Reinforcement Learning (RL) agents for the design and optimization of chemical process flowsheets (CPFs): a discrete masked Proximal Policy Optimization (mPPO) and a hybrid masked Proximal Policy Optimization (mHPPO). The novelty of this work lies in the use of masking within the hybrid framework, i.e., the incorporation of expert input or design rules that allows the exclusion of actions from the agent's decision spectrum. This work distinguishes from others by seamlessly integrating masked agents with rigorous unit operations (UOs) models, that is, advanced thermodynamic and conservation balance equations, in its simulation environment to design and optimize CPF. The efficacy of these agents, along with performance comparisons, is evaluated through case studies, including one that employs a chemical engineering simulator such as ASPEN Plus®. The results of these case studies reveal learning on the part of the agents, that is, the agent is able to find viable flowsheet designs that meet the stipulated process flowsheet design requirements, for example, achieve a user‐defined product quality.
{"title":"A reinforcement learning approach with masked agents for chemical process flowsheet design","authors":"Simone Reynoso‐Donzelli, Luis Alberto Ricardez‐Sandoval","doi":"10.1002/aic.18584","DOIUrl":"https://doi.org/10.1002/aic.18584","url":null,"abstract":"This study introduces two novel Reinforcement Learning (RL) agents for the design and optimization of chemical process flowsheets (CPFs): a discrete masked Proximal Policy Optimization (mPPO) and a hybrid masked Proximal Policy Optimization (mHPPO). The novelty of this work lies in the use of masking within the hybrid framework, i.e., the incorporation of expert input or design rules that allows the exclusion of actions from the agent's decision spectrum. This work distinguishes from others by seamlessly integrating masked agents with rigorous unit operations (UOs) models, that is, advanced thermodynamic and conservation balance equations, in its simulation environment to design and optimize CPF. The efficacy of these agents, along with performance comparisons, is evaluated through case studies, including one that employs a chemical engineering simulator such as ASPEN Plus®. The results of these case studies reveal learning on the part of the agents, that is, the agent is able to find viable flowsheet designs that meet the stipulated process flowsheet design requirements, for example, achieve a user‐defined product quality.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"2014 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142101522","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 Fe‐Pd bifunctional heterogeneous electro‐Fenton catalyst is an attractive option for the degradation of phenol wastewater. However, the catalyst faces issues such as inadequate yield of H2O2 on the Pd species and poor durability. In this study, we developed a bifunctional Fe‐Pd catalyst with Zn embedded into a mesh‐type γ‐Al2O3/Al support (ZnxFePd/γ‐Al2O3/Al). The characterization results indicate that the addition of Zn can improve the dispersion of the Pd component on the catalyst surface and promote the crystallization of Fe3O4. Density functional theory calculations reveal that Zn doping reduces the activation energy of the rate‐controlled step and promotes the desorption of products and intermediates in H2O2 synthesis. The reaction kinetics model was proposed. Furtherly, a possible reaction mechanism was proposed to explain the phenol degradation pathways. The selected Zn1.4FePd/γ‐Al2O3/Al catalyst achieved a degradation rate of 98.8% for phenol. The degradation rate remained above 85% after seven cycles.
{"title":"Development of Zn doping Fe‐Pd bifunctional mesh‐type catalyst for heterogeneous electro‐Fenton system","authors":"Wenwen Zhang, Wenbin Xie, Tianen Ma, Qi Zhang","doi":"10.1002/aic.18604","DOIUrl":"https://doi.org/10.1002/aic.18604","url":null,"abstract":"The Fe‐Pd bifunctional heterogeneous electro‐Fenton catalyst is an attractive option for the degradation of phenol wastewater. However, the catalyst faces issues such as inadequate yield of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> on the Pd species and poor durability. In this study, we developed a bifunctional Fe‐Pd catalyst with Zn embedded into a mesh‐type γ‐Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Al support (Zn<jats:sub><jats:italic>x</jats:italic></jats:sub>FePd/γ‐Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Al). The characterization results indicate that the addition of Zn can improve the dispersion of the Pd component on the catalyst surface and promote the crystallization of Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>. Density functional theory calculations reveal that Zn doping reduces the activation energy of the rate‐controlled step and promotes the desorption of products and intermediates in H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> synthesis. The reaction kinetics model was proposed. Furtherly, a possible reaction mechanism was proposed to explain the phenol degradation pathways. The selected Zn<jats:sub>1.4</jats:sub>FePd/γ‐Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Al catalyst achieved a degradation rate of 98.8% for phenol. The degradation rate remained above 85% after seven cycles.","PeriodicalId":120,"journal":{"name":"AIChE Journal","volume":"6 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142101557","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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