Industrial control system oscillations pose significant operational challenges, causing economic losses through energy waste, equipment degradation, and reduced product quality. Traditional detection methods rely heavily on manual expert analysis, creating scalability constraints in facilities with thousands of control loops. This paper presents a novel framework integrating Large Language Models (LLMs) with specialized oscillation detection toolboxes through Retrieval-Augmented Generation (RAG). The system features a command-line interface enabling seamless programmatic interaction between LLMs and analytical tools, eliminating GUI dependencies. A domain-specific RAG architecture combines real-time analytical outputs with technical knowledge repositories, while natural language processing capabilities allow industrial personnel to query systems using everyday language. The framework incorporates triangle-like shape detection algorithms enhanced by intelligent LLM interpretation. Validation using industrial datasets from refinery operations, the International Stiction Database, and the Tennessee Eastman Process benchmark demonstrates substantial performance improvements, achieving excellent classification accuracy and correlation values exceeding 0.96, effectively democratizing access to advanced oscillation analysis capabilities.
{"title":"Oscillation analysis using Retrieval-Augmented Generation","authors":"Abhijeet Singh , Mohammadhossein Modir Rousta , Biao Huang","doi":"10.1016/j.compchemeng.2025.109489","DOIUrl":"10.1016/j.compchemeng.2025.109489","url":null,"abstract":"<div><div>Industrial control system oscillations pose significant operational challenges, causing economic losses through energy waste, equipment degradation, and reduced product quality. Traditional detection methods rely heavily on manual expert analysis, creating scalability constraints in facilities with thousands of control loops. This paper presents a novel framework integrating Large Language Models (LLMs) with specialized oscillation detection toolboxes through Retrieval-Augmented Generation (RAG). The system features a command-line interface enabling seamless programmatic interaction between LLMs and analytical tools, eliminating GUI dependencies. A domain-specific RAG architecture combines real-time analytical outputs with technical knowledge repositories, while natural language processing capabilities allow industrial personnel to query systems using everyday language. The framework incorporates triangle-like shape detection algorithms enhanced by intelligent LLM interpretation. Validation using industrial datasets from refinery operations, the International Stiction Database, and the Tennessee Eastman Process benchmark demonstrates substantial performance improvements, achieving excellent classification accuracy and correlation values exceeding 0.96, effectively democratizing access to advanced oscillation analysis capabilities.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"206 ","pages":"Article 109489"},"PeriodicalIF":3.9,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145594796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-18DOI: 10.1016/j.compchemeng.2025.109484
Elia Arnese-Feffin , Nidhish Sagar , Luis A. Briceno-Mena , Birgit Braun , Ivan Castillo , Caterina Rizzo , Linh Bui , Jinsuo Xu , Leo H. Chiang , Richard D. Braatz
Data-driven modeling enables the pursuit of model-based solutions when no or partial knowledge is available on the process of interest. The typically poor generalization performance of data-driven models can be improved by incorporating all available knowledge into the model development workflow, i.e. by hybrid modeling. However, how to incorporate this knowledge and what kind of knowledge to use have been strictly problem-dependent questions: whether a general framework for hybrid modeling can be devised remains an open research topic. In this article, we make the first step towards such an objective: we propose a method relying on theoretically sound modification of the objective function of data-driven models by incorporation of constraints derived from process knowledge, an approach that can be readily implemented in existing software packages with minimal overhead. We focus on an underutilized source of knowledge, i.e. qualitative knowledge. The proposed approach is demonstrated in two case studies, where we employ qualitative and quantitative process knowledge with varying degrees of complexity and discuss their effectiveness. Results show promising performance, paving the way for a truly general hybrid modeling framework.
{"title":"The incorporation of qualitative knowledge in hybrid modeling","authors":"Elia Arnese-Feffin , Nidhish Sagar , Luis A. Briceno-Mena , Birgit Braun , Ivan Castillo , Caterina Rizzo , Linh Bui , Jinsuo Xu , Leo H. Chiang , Richard D. Braatz","doi":"10.1016/j.compchemeng.2025.109484","DOIUrl":"10.1016/j.compchemeng.2025.109484","url":null,"abstract":"<div><div>Data-driven modeling enables the pursuit of model-based solutions when no or partial knowledge is available on the process of interest. The typically poor generalization performance of data-driven models can be improved by incorporating all available knowledge into the model development workflow, i.e. by hybrid modeling. However, how to incorporate this knowledge and what kind of knowledge to use have been strictly problem-dependent questions: whether a general framework for hybrid modeling can be devised remains an open research topic. In this article, we make the first step towards such an objective: we propose a method relying on theoretically sound modification of the objective function of data-driven models by incorporation of constraints derived from process knowledge, an approach that can be readily implemented in existing software packages with minimal overhead. We focus on an underutilized source of knowledge, i.e. <em>qualitative</em> knowledge. The proposed approach is demonstrated in two case studies, where we employ qualitative and quantitative process knowledge with varying degrees of complexity and discuss their effectiveness. Results show promising performance, paving the way for a truly general hybrid modeling framework.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109484"},"PeriodicalIF":3.9,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-17DOI: 10.1016/j.compchemeng.2025.109482
Youqiang Chen , Ridong Zhang , Furong Gao
Traditional fault diagnosis has limitations in dynamic condition adaptation and multimodal feature decoupling, while existing deep learning methods are limited by the localization of time series modeling, noise sensitivity and insufficient efficiency of multiscale feature fusion. Aiming at the above challenges, this paper proposes a multi-scale residual attention fault diagnosis network (MRAFDN) through hierarchical dynamic feature enhancement and spatio-temporal attention co-optimization mechanism. The innovation of this study lies in constructing a dual fusion framework integrating Dynamic Multi-Scale Channel Attention (MSCA) and Dilated Spatial Attention (DSA). Employing a 1D Residual Network (1D-ResNet) as the backbone architecture, residual connections preserve low-level information from raw signals, while cascaded optimization with dual attention mechanisms forms a comprehensive lifecycle fault characterization system spanning from micro fluctuations to macro drifts. This methodology theoretically addresses fundamental challenges including noise-feature coupling, coexistence of multiple fault modes and adaptability to dynamic operational conditions. The proposed method demonstrates significant robustness under strong noise for multi-class fault modes in TE chemical processes and industrial coke furnaces.
{"title":"Multi-scale residual attention networks with spatio-temporal attention co-optimization for industrial fault diagnosis","authors":"Youqiang Chen , Ridong Zhang , Furong Gao","doi":"10.1016/j.compchemeng.2025.109482","DOIUrl":"10.1016/j.compchemeng.2025.109482","url":null,"abstract":"<div><div>Traditional fault diagnosis has limitations in dynamic condition adaptation and multimodal feature decoupling, while existing deep learning methods are limited by the localization of time series modeling, noise sensitivity and insufficient efficiency of multiscale feature fusion. Aiming at the above challenges, this paper proposes a multi-scale residual attention fault diagnosis network (MRAFDN) through hierarchical dynamic feature enhancement and spatio-temporal attention co-optimization mechanism. The innovation of this study lies in constructing a dual fusion framework integrating Dynamic Multi-Scale Channel Attention (MSCA) and Dilated Spatial Attention (DSA). Employing a 1D Residual Network (1D-ResNet) as the backbone architecture, residual connections preserve low-level information from raw signals, while cascaded optimization with dual attention mechanisms forms a comprehensive lifecycle fault characterization system spanning from micro fluctuations to macro drifts. This methodology theoretically addresses fundamental challenges including noise-feature coupling, coexistence of multiple fault modes and adaptability to dynamic operational conditions. The proposed method demonstrates significant robustness under strong noise for multi-class fault modes in TE chemical processes and industrial coke furnaces.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109482"},"PeriodicalIF":3.9,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-17DOI: 10.1016/j.compchemeng.2025.109487
Ching-Mei Wen, Marianthi Ierapetritou
This study focuses the multi-objective optimization and multi-criteria decision-making (MCDM) framework for designing a sustainable bio-based isopropanol (bio-IPA) supply chain under uncertainty, using sugar beet as the primary feedstock. By applying a two-stage stochastic programming model, the research optimizes the five-tier supply chain from sugar beet farms through storage, sugar plants, IPA production, and retail distribution across Minnesota. The study addresses economic, environmental, and supply chain performance objectives while accounting for uncertainties in biomass yield and market demand fluctuations. Results shows a cost-optimal supply chain configuration that can adapt to demand surges, achieving up to 94 % service levels when a $2.5/kg penalty for unsatisfied demand is applied. The analysis highlights the dominant influence of biomass cost, which accounts for approximately 65 % of total production costs, underscoring its critical role in supply chain economics. As environmental constraints tighten (e.g., greenhouse gas emission caps), the system experiences rising unsatisfied demand penalties and operational challenges. Furthermore, the study applies MCDM techniques, including the Weighted Product Method and data-driven weighting methods such as the coefficient of variation and interval entropy, to rank alternative configurations. Ternary plots, reflect the economic, environmental, and operational (performance-based) dimensions, are proposed as a tool to visualize trade-offs across economic, environmental, and operational dimensions, enhancing informed decision-making by exploring a diverse range of weight distributions that reflect varying stakeholder values.
{"title":"Multi-criteria decision-making and multi-objective optimization of a sustainable bio-based isopropanol supply chain","authors":"Ching-Mei Wen, Marianthi Ierapetritou","doi":"10.1016/j.compchemeng.2025.109487","DOIUrl":"10.1016/j.compchemeng.2025.109487","url":null,"abstract":"<div><div>This study focuses the multi-objective optimization and multi-criteria decision-making (MCDM) framework for designing a sustainable bio-based isopropanol (bio-IPA) supply chain under uncertainty, using sugar beet as the primary feedstock. By applying a two-stage stochastic programming model, the research optimizes the five-tier supply chain from sugar beet farms through storage, sugar plants, IPA production, and retail distribution across Minnesota. The study addresses economic, environmental, and supply chain performance objectives while accounting for uncertainties in biomass yield and market demand fluctuations. Results shows a cost-optimal supply chain configuration that can adapt to demand surges, achieving up to 94 % service levels when a $2.5/kg penalty for unsatisfied demand is applied. The analysis highlights the dominant influence of biomass cost, which accounts for approximately 65 % of total production costs, underscoring its critical role in supply chain economics. As environmental constraints tighten (e.g., greenhouse gas emission caps), the system experiences rising unsatisfied demand penalties and operational challenges. Furthermore, the study applies MCDM techniques, including the Weighted Product Method and data-driven weighting methods such as the coefficient of variation and interval entropy, to rank alternative configurations. Ternary plots, reflect the economic, environmental, and operational (performance-based) dimensions, are proposed as a tool to visualize trade-offs across economic, environmental, and operational dimensions, enhancing informed decision-making by exploring a diverse range of weight distributions that reflect varying stakeholder values.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109487"},"PeriodicalIF":3.9,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.compchemeng.2025.109483
Mengze Zheng, Tao Zhang, Jing Cao, Zhong Chen, Jian Zou
Given the challenges associated with resource depletion and market volatility, accurate oil production forecasting has become a critical component for optimizing oilfield development and enhancing decision-making processes. In recent years, various machine learning and deep learning methods have been widely adopted. However, these approaches still exhibit significant limitations in terms of accuracy and generalizability, often failing to fully capture the complexities of dynamic reservoir environments and multivariate datasets. To address these challenges, we propose the temporal Kolmogorov–Arnold networks (TKAN), a novel deep learning architecture specifically designed for multivariate time-series forecasting in the context of oil production. TKAN integrates Kolmogorov–Arnold decomposition with adaptive spline-enhanced activation functions, enabling the model to effectively capture nonlinear relationships and temporal dependencies. This leads to substantial improvements over conventional techniques when dealing with noisy and dynamic datasets. In the experimental section, the proposed TKAN model is utilized to predict oil production in the Volve Field. A comparative analysis with benchmark models, such as random forest, long short-term memory networks (LSTM), temporal fusion transformer (TFT), and Kolmogorov–Arnold Networks (KAN) demonstrates the superiority of TKAN. These results confirm that TKAN not only retains the lightweight advantages of KAN but also significantly improves predictive accuracy by incorporating temporal modeling, underscoring its potential for time series prediction in the oil and gas industry.
{"title":"Oil production forecasting using temporal Kolmogorov–Arnold networks","authors":"Mengze Zheng, Tao Zhang, Jing Cao, Zhong Chen, Jian Zou","doi":"10.1016/j.compchemeng.2025.109483","DOIUrl":"10.1016/j.compchemeng.2025.109483","url":null,"abstract":"<div><div>Given the challenges associated with resource depletion and market volatility, accurate oil production forecasting has become a critical component for optimizing oilfield development and enhancing decision-making processes. In recent years, various machine learning and deep learning methods have been widely adopted. However, these approaches still exhibit significant limitations in terms of accuracy and generalizability, often failing to fully capture the complexities of dynamic reservoir environments and multivariate datasets. To address these challenges, we propose the temporal Kolmogorov–Arnold networks (TKAN), a novel deep learning architecture specifically designed for multivariate time-series forecasting in the context of oil production. TKAN integrates Kolmogorov–Arnold decomposition with adaptive spline-enhanced activation functions, enabling the model to effectively capture nonlinear relationships and temporal dependencies. This leads to substantial improvements over conventional techniques when dealing with noisy and dynamic datasets. In the experimental section, the proposed TKAN model is utilized to predict oil production in the Volve Field. A comparative analysis with benchmark models, such as random forest, long short-term memory networks (LSTM), temporal fusion transformer (TFT), and Kolmogorov–Arnold Networks (KAN) demonstrates the superiority of TKAN. These results confirm that TKAN not only retains the lightweight advantages of KAN but also significantly improves predictive accuracy by incorporating temporal modeling, underscoring its potential for time series prediction in the oil and gas industry.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109483"},"PeriodicalIF":3.9,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-13DOI: 10.1016/j.compchemeng.2025.109480
Zhineng Tao , Haoran Li , Tong Qiu
Crude oil scheduling is a critical but highly complex sequential decision-making problem in refinery operations. Traditional mathematical programming methods suffer from exponential computational complexity with increasing scale, while traditional reinforcement learning approaches struggle to guarantee the satisfaction of numerous process and product quality constraints. This highlights a critical issue in the current field of scheduling: the lack of an optimization methodology that can simultaneously achieve high computational efficiency and robust constraint satisfaction. To bridge this gap, we propose a novel hybrid framework based on constraint stratification. The framework embeds critical hard constraints, such as entity connectivity limit, directly into the scheduling environment for intrinsic satisfaction through action masking and shaping. Concurrently, it employs safe reinforcement learning algorithms to manage soft constraints, such as tank inventory levels and product quality specifications, by optimizing a primary objective while keeping constraint violations below a predefined threshold. Through comparative experiments on scheduling cases, the Constrained Policy Optimization algorithm was identified as the most effective safe reinforcement learning method. The results demonstrate that our proposed framework significantly outperforms traditional methods. It achieves the high computational efficiency and scalability of reinforcement learning while providing a much stronger safety guarantee than penalty-based approaches, offering a robust and practical solution for complex industrial scheduling problems.
{"title":"A hybrid framework of intrinsic constraint handling and safe reinforcement learning for crude oil scheduling","authors":"Zhineng Tao , Haoran Li , Tong Qiu","doi":"10.1016/j.compchemeng.2025.109480","DOIUrl":"10.1016/j.compchemeng.2025.109480","url":null,"abstract":"<div><div>Crude oil scheduling is a critical but highly complex sequential decision-making problem in refinery operations. Traditional mathematical programming methods suffer from exponential computational complexity with increasing scale, while traditional reinforcement learning approaches struggle to guarantee the satisfaction of numerous process and product quality constraints. This highlights a critical issue in the current field of scheduling: the lack of an optimization methodology that can simultaneously achieve high computational efficiency and robust constraint satisfaction. To bridge this gap, we propose a novel hybrid framework based on constraint stratification. The framework embeds critical hard constraints, such as entity connectivity limit, directly into the scheduling environment for intrinsic satisfaction through action masking and shaping. Concurrently, it employs safe reinforcement learning algorithms to manage soft constraints, such as tank inventory levels and product quality specifications, by optimizing a primary objective while keeping constraint violations below a predefined threshold. Through comparative experiments on scheduling cases, the Constrained Policy Optimization algorithm was identified as the most effective safe reinforcement learning method. The results demonstrate that our proposed framework significantly outperforms traditional methods. It achieves the high computational efficiency and scalability of reinforcement learning while providing a much stronger safety guarantee than penalty-based approaches, offering a robust and practical solution for complex industrial scheduling problems.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109480"},"PeriodicalIF":3.9,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-13DOI: 10.1016/j.compchemeng.2025.109481
Larissa Thaís Bruschi, Luiz Kulay, Moisés Teles dos Santos
Renewable Liquefied Gas (RLG) is emerging as a viable alternative to Liquefied Petroleum Gas (LPG), providing environmental benefits and strengthening energy security. However, the implementation of biofuels faces challenges such as long-term feedstock availability, technology scalability, facility site selection, and tax policies. This study proposes a Mixed Integer Linear Programming optimization model to support strategic and tactical RLG supply chain decisions in Brazil. The model determines the optimal feedstock purchasing, facility locations, processing capacities, material flows, and product distribution to maximize the Net Present Value (NPV), in a case study that explores the production of RLG from glycerol. For the economic feasibility of the supply chain the RLG selling price must be 80 % higher than that of LPG. The optimal network favors a centralized system, where transportation costs minimally impact NPV, while economies of scale lower investment and production costs. A decentralized approach is evaluated by limiting the installed production capacity. Although a decentralized network requires an RLG selling price 220 % higher than LPG, it allows smaller stakeholders to enter the market and achieves the same payback period as the centralized system. Sensitivity analysis on conversion yield shows that a 5 % efficiency increase shortens the payback period by four years and triples the NPV. The study highlights the importance of supply chain integration, cost reduction strategies, and policy incentives in enhancing RLG competitiveness, thereby contributing to its deployment despite facing economic and logistical challenges.
{"title":"An optimization framework for renewable liquefied gas supply chain: A case study on glycerol-based production","authors":"Larissa Thaís Bruschi, Luiz Kulay, Moisés Teles dos Santos","doi":"10.1016/j.compchemeng.2025.109481","DOIUrl":"10.1016/j.compchemeng.2025.109481","url":null,"abstract":"<div><div>Renewable Liquefied Gas (RLG) is emerging as a viable alternative to Liquefied Petroleum Gas (LPG), providing environmental benefits and strengthening energy security. However, the implementation of biofuels faces challenges such as long-term feedstock availability, technology scalability, facility site selection, and tax policies. This study proposes a Mixed Integer Linear Programming optimization model to support strategic and tactical RLG supply chain decisions in Brazil. The model determines the optimal feedstock purchasing, facility locations, processing capacities, material flows, and product distribution to maximize the Net Present Value (NPV), in a case study that explores the production of RLG from glycerol. For the economic feasibility of the supply chain the RLG selling price must be 80 % higher than that of LPG. The optimal network favors a centralized system, where transportation costs minimally impact NPV, while economies of scale lower investment and production costs. A decentralized approach is evaluated by limiting the installed production capacity. Although a decentralized network requires an RLG selling price 220 % higher than LPG, it allows smaller stakeholders to enter the market and achieves the same payback period as the centralized system. Sensitivity analysis on conversion yield shows that a 5 % efficiency increase shortens the payback period by four years and triples the NPV. The study highlights the importance of supply chain integration, cost reduction strategies, and policy incentives in enhancing RLG competitiveness, thereby contributing to its deployment despite facing economic and logistical challenges.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109481"},"PeriodicalIF":3.9,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-12DOI: 10.1016/j.compchemeng.2025.109479
Rui Chen , Husnain Ali , Shu Liang , Yuanqiang Zhou , Furong Gao
Dealing with non-stationary characteristics and revealing the symbol properties of causalities remain obstacles to performing fault root cause diagnosis (RCD) in industrial processes. Existing methods overlook these problems, leading to reduced RCD accuracy and a limited understanding of the dynamic characteristics of fault propagation. To address the above-mentioned problems, this paper proposes a correction symbol Granger causality (CSGC) approach. Firstly, to infer significant Granger causality (GC) from non-stationary processes, the cointegration relationships among variables are utilized to differentiate them and construct an error correction term, enabling the regression model to capture the long-term dependencies among fault variables better. Secondly, the self-explaining neural network is employed to further reveal the symbol properties of the fault variable from the fitted generalized coefficient matrix. Furthermore, two causal criteria of CSGC are established to test the significance level of GC and eliminate bidirectional causalities. Based on CSGC, a causal graph construction strategy containing information on symbol properties is developed for fault RCD and analysis of fault propagation paths. The analysis results of the numerical simulation system indicate that the various metrics of CSGC perform well, demonstrating its potential for accurate RCD and in-depth fault propagation analysis (Accuracy: 0.96, Sensitivity: 1.00, Specificity: 0.95, F1 score: 0.91). Finally, the effectiveness of RCD is validated through its application to the numerical simulation, the Tennessee Eastman process (TEP) and a real-world motor soft-foot fault.
{"title":"A correction symbol Granger causality approach to root cause diagnosis of non-stationary industrial processes","authors":"Rui Chen , Husnain Ali , Shu Liang , Yuanqiang Zhou , Furong Gao","doi":"10.1016/j.compchemeng.2025.109479","DOIUrl":"10.1016/j.compchemeng.2025.109479","url":null,"abstract":"<div><div>Dealing with non-stationary characteristics and revealing the symbol properties of causalities remain obstacles to performing fault root cause diagnosis (RCD) in industrial processes. Existing methods overlook these problems, leading to reduced RCD accuracy and a limited understanding of the dynamic characteristics of fault propagation. To address the above-mentioned problems, this paper proposes a correction symbol Granger causality (CSGC) approach. Firstly, to infer significant Granger causality (GC) from non-stationary processes, the cointegration relationships among variables are utilized to differentiate them and construct an error correction term, enabling the regression model to capture the long-term dependencies among fault variables better. Secondly, the self-explaining neural network is employed to further reveal the symbol properties of the fault variable from the fitted generalized coefficient matrix. Furthermore, two causal criteria of CSGC are established to test the significance level of GC and eliminate bidirectional causalities. Based on CSGC, a causal graph construction strategy containing information on symbol properties is developed for fault RCD and analysis of fault propagation paths. The analysis results of the numerical simulation system indicate that the various metrics of CSGC perform well, demonstrating its potential for accurate RCD and in-depth fault propagation analysis (Accuracy: 0.96, Sensitivity: 1.00, Specificity: 0.95, F1 score: 0.91). Finally, the effectiveness of RCD is validated through its application to the numerical simulation, the Tennessee Eastman process (TEP) and a real-world motor soft-foot fault.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109479"},"PeriodicalIF":3.9,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-10DOI: 10.1016/j.compchemeng.2025.109478
Zhiqiang Liu , Chong Kuai , Gang Wu , Ashun Zang
Traditional SOC estimation methods are susceptible to temperature variations and external disturbances, while conventional data-driven methods can effectively deal with these issues but struggle with nonlinear issues. The Kolmogorov–Arnold Network (KAN), a novel network configuration, demonstrates excellent performance in handling nonlinear problems. Nevertheless, the use of B-spline functions in KAN results in slow training speed. This paper proposes a novel neural architecture network, L-TKAN, by replacing the B-spline function (RMSE1.41%,MAE1.12%,R20.997444) with the Laplacian radial basis function (Laplacian RBF) (RMSE1.25%,MAE0.92%,R20.997988) to address this issue. The corresponding 300-epoch training times of these two configurations were 288 min and 375 min, respectively. The results demonstrate that the use of the Laplacian RBF not only significantly accelerates the training speed but also improves the model performance. Moreover, compared to the traditional Gaussian RBF, the Laplacian RBF also exhibits these two advantages (RMSE 1.35% and 1.39%; MAE 1% and 1.04%; R2 0.997657 and 0.997524, the shortest training time of 288 min and 294 min, respectively). During the experiments, we discovered the relationship between two key parameters (the number of center points and the decay factor ) of the Laplacian RBF. Based on this finding, we further improved the performance of the model-When the number of center points was 2, the RMSE decreased 0.06%. Furthermore, the best performance was achieved with 1 center point, yielding an RMSE of 1.25%, MAE of 0.92%, and R2 of 0.997988. The proposed model also outperforms other models, such as KAN, MLP, LSTM, GRU, TCN, CNNLSTM, CNNGRU, transformer, CNNtransformer.
{"title":"L-TKAN:A fast and accurate Laplacian radial basis function-Based Temporal Kolmogorov–Arnold Network for state of charge estimation of lithium-ion batteries","authors":"Zhiqiang Liu , Chong Kuai , Gang Wu , Ashun Zang","doi":"10.1016/j.compchemeng.2025.109478","DOIUrl":"10.1016/j.compchemeng.2025.109478","url":null,"abstract":"<div><div>Traditional SOC estimation methods are susceptible to temperature variations and external disturbances, while conventional data-driven methods can effectively deal with these issues but struggle with nonlinear issues. The Kolmogorov–Arnold Network (KAN), a novel network configuration, demonstrates excellent performance in handling nonlinear problems. Nevertheless, the use of B-spline functions in KAN results in slow training speed. This paper proposes a novel neural architecture network, L-TKAN, by replacing the B-spline function (RMSE1.41%,MAE1.12%,R<sup>2</sup>0.997444) with the Laplacian radial basis function (Laplacian RBF) (RMSE1.25%,MAE0.92%,R<sup>2</sup>0.997988) to address this issue. The corresponding 300-epoch training times of these two configurations were 288 min and 375 min, respectively. The results demonstrate that the use of the Laplacian RBF not only significantly accelerates the training speed but also improves the model performance. Moreover, compared to the traditional Gaussian RBF, the Laplacian RBF also exhibits these two advantages (RMSE 1.35% and 1.39%; MAE 1% and 1.04%; R<sup>2</sup> 0.997657 and 0.997524, the shortest training time of 288 min and 294 min, respectively). During the experiments, we discovered the relationship between two key parameters (the number of center points and the decay factor <span><math><mi>σ</mi></math></span>) of the Laplacian RBF. Based on this finding, we further improved the performance of the model-When the number of center points was 2, the RMSE decreased 0.06%. Furthermore, the best performance was achieved with 1 center point, yielding an RMSE of 1.25%, MAE of 0.92%, and R<sup>2</sup> of 0.997988. The proposed model also outperforms other models, such as KAN, MLP, LSTM, GRU, TCN, CNNLSTM, CNNGRU, transformer, CNNtransformer.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109478"},"PeriodicalIF":3.9,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-31DOI: 10.1016/j.compchemeng.2025.109477
Ahmed Bichri , Yousra Jbari , Souad Abderafi
The attack and maturation unit represents the key step in the wet phosphoric acid production process. It must ensure optimal conversion of natural phosphate into phosphoric acid, while minimizing P₂O₅ losses, to improve the overall efficiency of the process. The aim of this study consists to reduce the three P₂O₅ losses (water-soluble, co-crystallized and non-attacked), in the phosphoric acid production attack and maturation unit. An industrial database, relating to the three losses of filters A and B as a function of the operating variables of the wet phosphoric acid production process, was analyzed. After processing, it was used for the development of an appropriate model, using the artificial neural network to predict the three P₂O₅ losses. The developed model with an optimal structure (5–3–6) presented good statistical performance. After validation of the model, it was used as an objective function for the NSGA-III algorithm to perform a multi-objective optimization, to minimize P₂O₅ losses. The results obtained lead to an improvement in the overall efficiency, which reaches 95.56 %, i.e. a gain of 0.34 % compared to the average observed efficiency.
{"title":"Multi-objective optimization of phosphoric acid production unit, to minimize P2O5 losses","authors":"Ahmed Bichri , Yousra Jbari , Souad Abderafi","doi":"10.1016/j.compchemeng.2025.109477","DOIUrl":"10.1016/j.compchemeng.2025.109477","url":null,"abstract":"<div><div>The attack and maturation unit represents the key step in the wet phosphoric acid production process. It must ensure optimal conversion of natural phosphate into phosphoric acid, while minimizing P₂O₅ losses, to improve the overall efficiency of the process. The aim of this study consists to reduce the three P₂O₅ losses (water-soluble, co-crystallized and non-attacked), in the phosphoric acid production attack and maturation unit. An industrial database, relating to the three losses of filters A and B as a function of the operating variables of the wet phosphoric acid production process, was analyzed. After processing, it was used for the development of an appropriate model, using the artificial neural network to predict the three P₂O₅ losses. The developed model with an optimal structure (5–3–6) presented good statistical performance. After validation of the model, it was used as an objective function for the NSGA-III algorithm to perform a multi-objective optimization, to minimize P₂O₅ losses. The results obtained lead to an improvement in the overall efficiency, which reaches 95.56 %, i.e. a gain of 0.34 % compared to the average observed efficiency.</div></div>","PeriodicalId":286,"journal":{"name":"Computers & Chemical Engineering","volume":"205 ","pages":"Article 109477"},"PeriodicalIF":3.9,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}