{"title":"Decarbonizing the chemical industry through digital technologies","authors":"Kathleen B. Aviso","doi":"10.1016/j.dche.2025.100250","DOIUrl":"10.1016/j.dche.2025.100250","url":null,"abstract":"<div><div>There are several challenges to decarbonizing the chemical industry as it utilizes significant amounts of fossil fuels as feedstock and as source of energy. As a result, the industry contributes about 5 % to global CO<sub>2</sub> emissions. Various strategies and technologies which include the use of alternative feedstock, electrification, and negative emissions technologies are available to aid in the industry’s decarbonization. These strategies can be implemented at different stages of the chemical production life cycle. The adoption of digital technologies has reported improvements in the economic, environmental, and societal performance of manufacturing industries. This review intends to investigate how available digital technologies can be utilized to accelerate the decarbonization of the chemical industry.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100250"},"PeriodicalIF":3.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AutoRL framework for bioprocess control: Optimizing reward function, architecture, and hyperparameters","authors":"D.A. Goulart , R.D. Pereira , F.V. Silva","doi":"10.1016/j.dche.2025.100261","DOIUrl":"10.1016/j.dche.2025.100261","url":null,"abstract":"<div><div>This study proposes a structured AutoRL framework for the development of deep reinforcement learning (DRL) controllers in chemical process systems. Focusing on the control of a 3<span><math><mo>×</mo></math></span> 3 MIMO yeast fermentation bioreactor, the methodology jointly optimizes three key internal components of the DRL agent: the reward function, the neural network architecture, and the hyperparameters of the algorithm. A parameterizable logistic reward formulation is introduced to encode control objectives, such as steady-state accuracy, minimalization of actuation effort, and control smoothness, into a flexible and tunable structure. A dual loop optimization strategy combines grid search and Bayesian optimization to systematically explore and refine the agent’s design space. The resulting controller achieved average steady-state errors of 0.009 °C for reactor temperature and 0.19 g/L for ethanol concentration, while maintaining smooth and stable behavior under diverse operational scenarios. By formalizing reward design and integrating it with hyperparameter and architecture optimization, this work delivers a AutoRL methodology for DRL-based control, reducing reliance on expert heuristics and enhancing reproducibility in complex bioprocess applications.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100261"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temporal PFD-guided graph convolutional networks: a novel approach to process modeling","authors":"Hiroki Horiuchi, Yoshiyuki Yamashita","doi":"10.1016/j.dche.2025.100260","DOIUrl":"10.1016/j.dche.2025.100260","url":null,"abstract":"<div><div>The present study proposes a novel methodology to construct a regression model of process systems, namely, temporal PFD-guided graph convolutional networks (GCN). The approach integrates domain knowledge derived from process flow diagrams (PFDs) and controller configurations into a GCN framework, enabling enhanced state estimation in chemical processes. We introduce a process topology with temporal propagation derived from PFDs to construct robust graph structures for GCNs. The proposed method integrates causal relationships among process variables and their time-series dependencies, enhancing prediction accuracy and adaptability. A case study of a concentration estimation on the Tennessee Eastman Process (TEP) demonstrates the effectiveness of the PFD-guided GCN. The results indicate significant improvements in prediction accuracy compared to 1D-CNN, especially under abnormal operating conditions and when limited training data is available. This approach provides a practical and generalizable solution for process state estimation and soft sensor applications in dynamic and data-sparse industrial environments.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100260"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hybrid neural networks for improved chemical process modeling: Bridging data-driven insights with physical consistency","authors":"Jana Mousa, Stéphane Negny, Rachid Ouaret","doi":"10.1016/j.dche.2025.100256","DOIUrl":"10.1016/j.dche.2025.100256","url":null,"abstract":"<div><div>The increasing reliance on neural networks (NN) in chemical process modeling highlights their capability for accurate predictions, yet their standalone application often struggles to adhere to fundamental physical laws such as equilibrium constraints and mass balance. Addressing this limitation, hybrid methods that integrate data-driven insights with physical consistency have gained prominence. This study systematically explores the integration of NNs with nonlinear data reconciliation (NDR) across multiple testing dimensions, including a Gibbs reactor, data robustness evaluations, and reactor-distillation system integration. Hybrid methodologies such as NN + NDR, NN + KKT (Karush-Kuhn-Tucker), and KKT + PINN (Physics-Informed Neural Networks with KKT conditions) are comparatively assessed. The proposed NN + NDR framework demonstrates superior performance in minimizing errors and enforcing physical laws, with minimal computational overhead. This work emphasizes the scalability, robustness, and transformative potential of modular hybrid strategies in advancing reliable, physically consistent chemical process modeling.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100256"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arthur Khodaverdian , Dhruv Gohil , Panagiotis D. Christofides
{"title":"Neural network implementation of model predictive control with stability guarantees","authors":"Arthur Khodaverdian , Dhruv Gohil , Panagiotis D. Christofides","doi":"10.1016/j.dche.2025.100262","DOIUrl":"10.1016/j.dche.2025.100262","url":null,"abstract":"<div><div>This work explores the use of supervised learning on data generated by a model predictive controller (MPC) to train a neural network (NN). The goal is to create an approximate control policy that can replace the MPC, offering reduced computational complexity while maintaining stability guarantees. Through the use of Lyapunov-based stability constraints, an MPC can be designed to guarantee stability. Once designed, this MPC can be used to generate a dataset of various state-space points and their resulting immediate optimal control actions. With the MPC dataset representing an optimal control policy, an NN is trained to function as a direct substitute for the MPC. The resulting approximate control policy can then be applied in real-time to the process, with stability guarantees being enforced through post-inference validation. If, for a given set of sensor readings, the NN yields control actions that violate the Lyapunov stability constraints used in the MPC, the control action is discarded and replaced with stabilizing control from a fallback stabilizing controller. This control architecture is applied to a benchmark chemical reactor model. Using this model, a comprehensive study of the stability, performance, robustness, and computational burden of the approach is carried out.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100262"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rei Tamaki , Yusuke Hayashi , Yuki Uno , Masahiro Kino-oka , Hirokazu Sugiyama
{"title":"A circular exploration of cryoprotective agents for stem cells using computer-aided molecular design approaches","authors":"Rei Tamaki , Yusuke Hayashi , Yuki Uno , Masahiro Kino-oka , Hirokazu Sugiyama","doi":"10.1016/j.dche.2025.100248","DOIUrl":"10.1016/j.dche.2025.100248","url":null,"abstract":"<div><div>This work presents a circular exploration of cryoprotective agents (CPAs) for stem cells using computer-aided molecular design approaches that can comprehensively consider compounds. An exploration cycle was developed that consists of the following five steps: setting conditions, computational evaluation, experimental evaluation, verification experiments, and discussions with experts in biotechnology. It aims to discover promising CPA candidate compounds by incorporating domain knowledge through discussions with the experts. The developed cycle can be applied to fields where the required physical properties have not been clearly known. As a result, 1-methylimidazole and pyridazine were selected as promising CPA candidate compounds, which were both heterocyclic amines. Hence, heterocyclic amines could be a stepping-stone toward the future development of CPAs for stem cells. By repeatedly using the exploration cycle, CPA candidate compounds with better cryoprotective effects could be discovered.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100248"},"PeriodicalIF":3.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oktorifo Gardiola , Abdulhalim Shah Maulud , Muhammad Nawaz , Nabila Farhana Jamaludin
{"title":"Fault detection using multiscale recursive principal component analysis for chemical process systems","authors":"Oktorifo Gardiola , Abdulhalim Shah Maulud , Muhammad Nawaz , Nabila Farhana Jamaludin","doi":"10.1016/j.dche.2025.100264","DOIUrl":"10.1016/j.dche.2025.100264","url":null,"abstract":"<div><div>Process monitoring is essential for maintaining operational safety and product quality in chemical industries. Although conventional fault detection techniques are widely used, their static nature often leads to high false alarm rates (FAR) and missed detection rates (MDR) under dynamic conditions. To address these limitations, this study proposes a Multiscale Recursive Principal Component Analysis (MSRPCA)-based fault detection framework that combines multiscale signal decomposition with the adaptive capabilities of Recursive PCA (RPCA). The MSRPCA approach isolates process variations across different frequency bands while continuously updating the Principal Component Analysis (PCA) model using a moving window mechanism. This enables real-time adaptability and enhanced noise resistance. The proposed method is validated using the Tennessee Eastman Process (TEP), a widely used benchmark for chemical process monitoring under a range of fault types, including step, drift, and random variation disturbances. Fault detection performance is quantitatively assessed using FAR and MDR metrics across 20 distinct fault scenarios. The results demonstrate that MSRPCA consistently outperforms traditional techniques, significantly reducing false alarms while improving fault detection accuracy. For instance, in Fault 16, the MDR in the Hotelling’s <em>T</em><sup><em>2</em></sup> (<em>T</em><sup><em>2</em></sup>) chart decreased from 70.5 % (PCA) to 10.5 % (MSRPCA), while the FAR in the Squared Prediction Error (SPE) chart dropped from 21.3 % to 0 %. These findings underscore the robustness and effectiveness of MSRPCA for real-time fault detection in complex, time-varying, and noisy industrial environments.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100264"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Isabela Fons Moreno-Palancas, Rubén Ruiz Femenia, Raquel Salcedo Díaz, José A. Caballero
{"title":"Solving bilevel problems under uncertainty with embedded neural networks: Incorporating scenario sets as inputs","authors":"Isabela Fons Moreno-Palancas, Rubén Ruiz Femenia, Raquel Salcedo Díaz, José A. Caballero","doi":"10.1016/j.dche.2025.100253","DOIUrl":"10.1016/j.dche.2025.100253","url":null,"abstract":"<div><div>Bilevel optimization is a sub-field of optimization widely valued both in academia and business due to its suitability to identify the best solutions for hierarchical decision-making processes. The predominant approach to solving bilevel problems involves reformulating them as single-level equivalents that can be solved with commercial solvers. However, traditional reformulation techniques are often constrained by the complexity of the lower-level problem, particularly when the number of variables or constraints is large, or uncertain parameters are present.</div><div>Given the intrinsic presence of uncertainty in most real-world applications of bilevel optimization, this work proposes a metamodeling approach that approximates the lower level using a neural network. Although this strategy has been satisfactorily applied to deterministic bilevel models, we extend its use to stochastic bilevel problems by training a neural network that learns over a set of realizations of the uncertain parameters. Our methodology is tested on the short-term scheduling of a batch chemical process, a context where classical reformulation approaches become unmanageable due to the presence of differential equations. The results indicate that our approach successfully achieves a single-level reformulation that is computationally tractable and can be solved efficiently even in complex bilevel settings, provided that the lower-level remains manageable and the main complexity arises from its integration into the upper level.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100253"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cheick Dosso , Hector A. Pedrozo , Thien Tran , Lingxiang Zhu , Victor Kusuma , David Hopkinson , Lorenz T. Biegler , Grigorios Panagakos
{"title":"A computational investigation of high-flux, plate-and-frame membrane modules for industrial carbon capture","authors":"Cheick Dosso , Hector A. Pedrozo , Thien Tran , Lingxiang Zhu , Victor Kusuma , David Hopkinson , Lorenz T. Biegler , Grigorios Panagakos","doi":"10.1016/j.dche.2025.100246","DOIUrl":"10.1016/j.dche.2025.100246","url":null,"abstract":"<div><div>In this work, we study the application of membrane-based separation systems for carbon capture, considering plate-and-frame membrane modules. The successful deployment of membrane CO<sub>2</sub> capture systems relies on high-performing membranes, as well as on effective membrane modules that can fully exploit the developed membranes. A plate-and-frame membrane module is especially attractive for CO<sub>2</sub> capture from industrial flue gas, due to its reduced pressure drop compared to its counterparts such as spiral wound modules and hollow fiber modules. To design better plate-and-frame modules, we investigate their basic unit - a single membrane stack - through a combination of computational modeling and experimental investigations. The modeling approach is based on computational fluid dynamics (CFD) to represent the multiphysics problem, including the fluid flow and diffusion processes within the membrane stack. We use experimental data collected under different operating conditions to validate the CFD model. Numerical results suggest good agreement between experiments and model outputs for CO<sub>2</sub> recovery, CO<sub>2</sub> mole fractions in the retentate and permeate, and stage-cut. The CFD model is able to predict accurately the flow behavior, providing valuable insights into the effects of fluid dynamics on the mass transfer of CO<sub>2</sub>. CFD models achieve high accuracy by capturing complex permeate-side flow patterns exhibiting a 4.5 % maximum relative error compared to experiments. Results suggest that deviations of 1D models, assuming ideal flow patterns, from the CFD increase as separation properties improve with material advancements, and can be as high as 21 % for some cases. We also carry out a sensitivity analysis to identify the effect of key parameters on the CO<sub>2</sub> recovery and the CO<sub>2</sub> purity of the outlet streams.</div></div>","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100246"},"PeriodicalIF":3.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Editorial: Special issue on Emerging Stars in Digital Chemical Engineering","authors":"Jin Xuan , Jinfeng Liu","doi":"10.1016/j.dche.2025.100247","DOIUrl":"10.1016/j.dche.2025.100247","url":null,"abstract":"","PeriodicalId":72815,"journal":{"name":"Digital Chemical Engineering","volume":"16 ","pages":"Article 100247"},"PeriodicalIF":4.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}