ChemEngineering

13 pages, 816 KB

Open AccessArticle

Catalytic Activity of Multi-Boron-Doped Graphene from First Principles

by Rita Maji and Joydev De

ChemEngineering 2026, 10(3), 42; https://doi.org/10.3390/chemengineering10030042 - 17 Mar 2026

Viewed by 357

Metal-free electrodes are essential to promote electrochemical reactions, the core of sustainable energy resources. In search of better carbon-based electrode materials, we have explored several spatial arrangements of boron (B) within proximity in the graphene lattice, as evident in recent experimental observations. Multi-boron [...] Read more.

Metal-free electrodes are essential to promote electrochemical reactions, the core of sustainable energy resources. In search of better carbon-based electrode materials, we have explored several spatial arrangements of boron (B) within proximity in the graphene lattice, as evident in recent experimental observations. Multi-boron substitution enriches sites by tuning electronic structure and strengthens binding of key intermediates of oxygen reduction, oxygen evolution, and hydrogen evolution reactions facilitating electrocatalytic performance. Our optimal B-doped site shows near thermo-neutral H adsorption (

Δ G_{H^{*}}

∼

\pm 0.4 eV

), consistent with experiments. The overpotentials are highly sensitive to the dopant motifs and the spread among configurations shows that experimentally accessible multi-B doping can serve as a practical active site engineering knob to achieve optimized multi-functional performance. In parallel, we find that specific multi-B configurations selectively capture and pre-activate NO_x (NO/NO₂) under ambient conditions while retaining weak affinity for NH₃. These sites also interact with SO₂ and related hazardous species, enabling selective air filtration and targeted NO_x control within the electrocatalytic scope of this study. Full article

(This article belongs to the Special Issue Development of Devices for Electrochemical Energy Storage and Generation)

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19 pages, 1390 KB

Open AccessArticle

Particle Swarm Optimization of Pressure Swing Adsorption for Hydrogen Purification from Depleted Gas Fields

by Viktor Kalman and Michael Harasek

ChemEngineering 2026, 10(3), 41; https://doi.org/10.3390/chemengineering10030041 - 13 Mar 2026

Viewed by 291

Abstract

Pressure swing adsorption (PSA) is a viable method for separating hydrogen from gas mixtures, an important aspect of long-term hydrogen storage in depleted gas fields. This study explores optimizing a 12-step PSA process for recovering high-purity hydrogen from varying compositions of hydrogen–methane mixtures, [...] Read more.

Pressure swing adsorption (PSA) is a viable method for separating hydrogen from gas mixtures, an important aspect of long-term hydrogen storage in depleted gas fields. This study explores optimizing a 12-step PSA process for recovering high-purity hydrogen from varying compositions of hydrogen–methane mixtures, simulating the conditions likely encountered during hydrogen storage and recovery. Step-time optimization was performed on four different hydrogen–methane mixtures using the toPSAil simulation package—an open-source dynamic PSA simulator developed by researchers at the Georgia Institute of Technology—integrated with a particle swarm optimization (PSO) algorithm. The goal was to develop an optimization framework that can reliably identify PSA step times for different operating scenarios and satisfy specified purity and recovery constraints under fluctuating wellhead feed conditions. The optimization converged within 25–30 iterations, even in high-contaminant, low-pressure scenarios, where PSA performance is traditionally weak. The product purity in the optimized cycles was above 99.1% with more than 80% recovery for all cases, while fuel cell quality (99.7%) hydrogen was achieved in two out of the four scenarios. The purge-to-feed ratio of the best-performing cycles was between 0.07 and 0.32. These findings show the potential of the proposed approach in overcoming the difficulty of designing PSA cycles for non-constant gas compositions and achieving a hydrogen purification process suitable for variable feed conditions. The workflow generates a large synthetic dataset that can support surrogate or hybrid modeling. The results can help advance research in other gas separation areas with non-constant conditions, like flue gas or biogas purification. Full article

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55 pages, 13041 KB

Open AccessReview

Application, Challenges and Perspectives of Catalysts Applied in Power-to-X Technology to Produce Hydrogen-Derived Vectors for Energy Transition

by María Lorena Malagón-Quinto, Hilda Elizabeth Reynel-Ávila, Didilia Ileana Mendoza-Castillo, Adrián Bonilla-Petriciolet, Norma Aurea Rangel-Vázquez, Gloria Sandoval-Flores and Sarah Essam

ChemEngineering 2026, 10(3), 40; https://doi.org/10.3390/chemengineering10030040 - 12 Mar 2026

Viewed by 624

Abstract

This review analyzes the catalytic routes for the Power-to-X (PtX) conversion of hydrogen to methane, methanol, ammonia, formic acid, and synthetic hydrocarbon fuels. The key reactive synthesis technologies and catalysts for each vector are described. Recent studies and pilot projects summarizing the reaction [...] Read more.

This review analyzes the catalytic routes for the Power-to-X (PtX) conversion of hydrogen to methane, methanol, ammonia, formic acid, and synthetic hydrocarbon fuels. The key reactive synthesis technologies and catalysts for each vector are described. Recent studies and pilot projects summarizing the reaction pathways of each vector and the associated catalyst technologies are also discussed. The analysis indicates that catalyst selection critically influences the efficiency and selectivity of these reactive systems. Some catalyst synthesis routes rely on expensive critical minerals (e.g., Ru and Rh), which raise technical and economic challenges for their industrial application. Catalyst deactivation and scale-up limitations are also relevant issues to be resolved. Emerging catalysts (e.g., Fe–Co or Co–Ni bimetallics, core–shell materials, metal-organic frameworks (MOFs), electrides, covalent-organic frameworks (COFs), and perovskites) are being explored to enhance stability, selectivity, and deactivation. Europe leads PtX development to consolidate the industrial production of hydrogen-based vectors with strong policy support, while the industrial initiatives in Latin America are limited (for instance, Chile’s green methanol and ammonia projects are examples) despite its great potential to generate renewable energy. In summary, Power-to-X can store renewable energy and close the carbon loop; however, its industrial consolidation demands catalyst innovation and supportive regulatory frameworks to overcome the challenges highlighted in this review. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Derivatives)

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14 pages, 2814 KB

Open AccessArticle

Numerical Study on the Staged SCR Catalyst for Marine Exhaust After-Treatment

by Kyungbin Park, Hyeonseok Im, Gyu Ryeol Baek and Mino Woo

ChemEngineering 2026, 10(3), 39; https://doi.org/10.3390/chemengineering10030039 - 9 Mar 2026

Viewed by 293

Abstract

This study numerically investigates the NO removal performance of a staged catalyst substrate employed in an industrial marine after-treatment system. The computational domain is based on the lab-scale experimental device used for measuring pressure drop, serving as a digital twin to accurately reproduce [...] Read more.

This study numerically investigates the NO removal performance of a staged catalyst substrate employed in an industrial marine after-treatment system. The computational domain is based on the lab-scale experimental device used for measuring pressure drop, serving as a digital twin to accurately reproduce the staged catalyst configuration prior to its application in full-scale industrial reactors. Experiments were conducted to estimate the parameters for a porous model, employed for efficient computation of flow and reactive mass transfer inside the catalyst substrate without needing a complex computational mesh of the monolith structure. A reaction mechanism from the literature was modified and verified for marine SCR reactors. The three-dimensional numerical simulations in this study indicate that the NO removal in the staged catalyst substrate varies depending on the catalyst configuration, primarily due to differences in the upstream flow uniformity. This study demonstrates that relocating a single catalyst substrate to the downstream position improved conversion by 6.5 percentage points, while a two-stage catalyst configuration yielded a 15.5 percentage-point increase under identical exhaust conditions. In addition, the residence time exhibited significant variations depending on the catalyst arrangement and inlet velocity, highlighting it as a critical parameter governing NO reduction performance. The findings in the present study can serve as a reference for future analyses conducted under practical conditions in industrial-scale marine SCR systems. Full article

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22 pages, 5226 KB

Open AccessArticle

Sequential Anaerobic–Aerobic Treatment of Paint Wastewater: Performance and LC–MS Pollutant Transformation

by E. S. Manju and Basavaraju Manu

ChemEngineering 2026, 10(3), 38; https://doi.org/10.3390/chemengineering10030038 - 5 Mar 2026

Viewed by 425

Abstract

Paint manufacturing wastewater contains complex mixtures of solvents, resins, surfactants, pigments, and polymeric additives that result in high chemical oxygen demand (COD), toxicity, and poor biodegradability. Conventional physicochemical treatment provides limited removal of dissolved organics, and the pollutant-level behavior of paint effluents during [...] Read more.

Paint manufacturing wastewater contains complex mixtures of solvents, resins, surfactants, pigments, and polymeric additives that result in high chemical oxygen demand (COD), toxicity, and poor biodegradability. Conventional physicochemical treatment provides limited removal of dissolved organics, and the pollutant-level behavior of paint effluents during biological treatment remains insufficiently characterized. This study addresses this gap by evaluating a sequential anaerobic–aerobic batch process treating three distinct synthetic paint wastewater samples. This study is a comparative investigation of sequential biological treatment across multiple paint wastewater variants, combined with high-resolution LC–MS to track compound-level transformations. Treatment performance was assessed through COD removal, biogas generation, pH and redox behavior, and LC–MS profiling of organic contaminants. The anaerobic stage achieved 70–95% COD removal depending on wastewater type. Aerobic polishing increased overall removal efficiencies, while PWW3 exhibited reduced stability during extended operation. LC–MS analysis showed substantial decreases in the number and intensity of chromatographic peaks and demonstrated degradation of phthalates, glycol ethers, organophosphate plasticizers, and solvent-derived compounds. The study provides integrated performance- and pollutant-level assessment of sequential anaerobic–aerobic treatment of paint wastewater and demonstrates the influences of wastewater heterogeneity in biological degradation pathways. Full article

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14 pages, 6687 KB

Open AccessArticle

Investigation on the Influence of Chemical Compounds in the Failure Mechanism Puncture Zones in Reinforced Rubber

by Vasile Gheorghe, Dan Cristian Cuculea and Eliza Chircan

ChemEngineering 2026, 10(3), 37; https://doi.org/10.3390/chemengineering10030037 - 4 Mar 2026

Viewed by 289

Abstract

This study investigates the fatigue failure of fiber-reinforced rubber used in automotive shock-absorbing elements subjected to cyclic loads. A quantitative simulation model integrated with material analysis to predict the service life and performance decay of these viscoelastic dampers was introduced. Failure is governed [...] Read more.

This study investigates the fatigue failure of fiber-reinforced rubber used in automotive shock-absorbing elements subjected to cyclic loads. A quantitative simulation model integrated with material analysis to predict the service life and performance decay of these viscoelastic dampers was introduced. Failure is governed by a degradation factor that models accumulating fatigue damage and results in a predictable, cyclic loss of maximum force capacity; specifically, the model accurately predicts a 36.3% reduction in peak force (from 111.44 N to 70.97 N) over the first 10 fatigue cycles. Crucially, the model incorporates the non-linear stiffness behavior caused by a fiber pull-out mechanism, which transitions load resistance from high elastic integrity to lower frictional forces post-critical displacement. These findings establish a direct, quantitative link between microstructural failure (verified via SEM) and observed performance decay, offering key insights for maintenance planning and material selection. Full article

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25 pages, 1792 KB

Open AccessReview

Friedel–Crafts: A Key Step in the Synthesis of Pharmaceutical Compounds

by Konstantinos Anthopoulos, Stefanos Michailidis, Zafeiro Thomaidou, Lydia Vogiatzaki and Nikolaos C. Kokkinos

ChemEngineering 2026, 10(3), 36; https://doi.org/10.3390/chemengineering10030036 - 4 Mar 2026

Viewed by 924

Abstract

This comprehensive review provides a consolidated and practically oriented overview of the Friedel–Crafts reaction in pharmaceutical synthesis, bringing together data from 93 peer-reviewed studies published between 1962 and 2025. Through a structured and comparative analysis of the literature retrieved from the Scopus and [...] Read more.

This comprehensive review provides a consolidated and practically oriented overview of the Friedel–Crafts reaction in pharmaceutical synthesis, bringing together data from 93 peer-reviewed studies published between 1962 and 2025. Through a structured and comparative analysis of the literature retrieved from the Scopus and PubMed databases, this work integrates scattered information into a single, accessible resource, designed to guide researchers in drug discovery and development. The findings identify alkylation and acylation as the dominant Friedel–Crafts transformations, often enabling the synthesis of pharmacologically relevant scaffolds depending on substrate structure and the efficiency and selectivity of the catalytic system. These include compounds with anticancer, anti-inflammatory, and antimicrobial potential. Trends in catalyst and solvent selection highlight both the persistent reliance on classical Lewis acids in chlorinated media and a gradual interest in more sustainable alternatives, although their adoption remains system-dependent. By consolidating 63 years of research into a unified reference, this review underscores the versatility and enduring relevance of Friedel–Crafts methodologies in medicinal chemistry but also offers a data-driven foundation for their optimized and more sustainable application in future pharmaceutical development. Full article

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16 pages, 1347 KB

Open AccessArticle

Machine Learning (ML) Modeling of CO₂ Liquid–Vapour Equilibrium (LVE) Absorption in Amine Aqueous Solutions

by Timur-Vasile Chis, Monica Tegledi, Laurentiu Prodea, Alina Maria Faladau, Sadigov Murat, Mammadov Elmir, Anamaria Niculescu, Iolanda Popa and Tiberiu Sandu

ChemEngineering 2026, 10(3), 35; https://doi.org/10.3390/chemengineering10030035 - 3 Mar 2026

Viewed by 424

Abstract

Predicting CO₂ absorption behavior in aqueous amine systems is a critical challenge for optimizing carbon capture technologies. This research develops a high-precision Artificial Neural Network (ANN) to simulate equilibrium data across various amine classes, including primary (MEA, DGA), secondary (DEA, DPA), and [...] Read more.

Predicting CO₂ absorption behavior in aqueous amine systems is a critical challenge for optimizing carbon capture technologies. This research develops a high-precision Artificial Neural Network (ANN) to simulate equilibrium data across various amine classes, including primary (MEA, DGA), secondary (DEA, DPA), and tertiary (MDEA) amines. The model architecture utilizes a Multi-Layer Perceptron (MLP) trained on a dataset split into 70% training, 15% validation, and 15% testing segments to prevent overfitting and ensure reliable generalization. By employing a Sigmoid activation function, the network achieved a coefficient of determination (R²) exceeding 0.98 and an absolute average relative deviation (AARD) below 5%. Furthermore, this study evaluates the efficacy of classical isotherms (Langmuir, Freundlich, and Temkin) strictly as empirical curve-fitting correlations for liquid-phase behavior. Results indicate that while these models are traditionally surface-adsorption based, the Langmuir form provides a mathematically robust fit for the tertiary amine MDEA (R² = 0.9673). Experimental observations indicate that Monoethanolamine (MEA) maintains the highest capacity for CO₂ uptake. Since the model relies on categorical descriptors for amine types, it offers a rapid and efficient framework for assessing specific solvents in post-combustion capture infrastructure. Full article

(This article belongs to the Special Issue AI-Driven Digital Twin for Process Safety in Chemical Engineering)

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36 pages, 2532 KB

Open AccessReview

Material-Based Hydrogen Storage Technologies: A Frontier Overview of Systems, Challenges, and Machine Learning Integration

by Haval Kukha Hawez, Jaidon Jibi Kurisinkal and Taimoor Asim

ChemEngineering 2026, 10(3), 34; https://doi.org/10.3390/chemengineering10030034 - 3 Mar 2026

Cited by 1 | Viewed by 983

Abstract

The intermittency of renewable-based power is a major barrier for long-term supply of clean energy, which necessitates the development of reliable solutions for clean energy storage and transition towards a carbon-neutral economy. Although hydrogen has emerged as a promising clean energy carrier to [...] Read more.

The intermittency of renewable-based power is a major barrier for long-term supply of clean energy, which necessitates the development of reliable solutions for clean energy storage and transition towards a carbon-neutral economy. Although hydrogen has emerged as a promising clean energy carrier to address this, its high compressibility requires safe, efficient and practical storage technologies for widespread deployment. Surface storage technologies for hydrogen have garnered attention due to their mobile and stationary applications, paving the way for a future hydrogen-based economy. This review provides a comprehensive review of surface hydrogen storage technologies, covering metal hydrides, metal-organic frameworks (MOFs), liquid organic hydrogen carriers (LOHCs), glass microspheres, capillary arrays, etc. Where previous reviews mostly address the chemistry behind these storage technologies, this study highlights practical integration and techno-economic assessment. Comparative analysis reveals that while LOHC and hydrides dominate in Technology Readiness Level, MOFs and carbohydrate-based systems offer high gravimetric potential, though they are currently quite costly. Other challenges like thermal management and large-scale regeneration remain critical for practical deployment. Moreover, recent advancements in Artificial Intelligence and Machine Learning offer unique insights, demonstrating their growing role in material screening, performance prediction, and the optimization of storage system designs. This review outlines the key challenges and research pathways required to support future deployment. Full article

(This article belongs to the Special Issue Development of Devices for Electrochemical Energy Storage and Generation)

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26 pages, 13990 KB

Open AccessArticle

From Baker’s Yeast to Skin Rejuvenation: Insights into the Anti-Wrinkle Properties of Chitin–Glucans Extracted from Saccharomyces cerevisiae

by Xiaosong Wang, Mojtaba Koosha, Tianduo Li, Yinghua Gong and Vladimir A. Vinokurov

ChemEngineering 2026, 10(3), 33; https://doi.org/10.3390/chemengineering10030033 - 2 Mar 2026

Cited by 1 | Viewed by 552

Abstract

While Saccharomyces cerevisiae (baker’s yeast) offers a safe, non-animal source of chitin-glucan (CG), its potential as a functional cosmetic ingredient has been overshadowed by industrial sources like Aspergillus niger. This study advances the existing literature by establishing a critical structure–function relationship for [...] Read more.

While Saccharomyces cerevisiae (baker’s yeast) offers a safe, non-animal source of chitin-glucan (CG), its potential as a functional cosmetic ingredient has been overshadowed by industrial sources like Aspergillus niger. This study advances the existing literature by establishing a critical structure–function relationship for CG micro/nano particles extracted via three physical disruption methods: ultrasonic bath, ultrasonic probe, and autoclaving. The obtained CG was systematically characterized by physicochemical and biological tests. A significant trade-off was identified: while autoclaving (40 min) resulted in lower mass yield compared to ultrasonication, it produced particles with the highest crystallinity, an enriched chitin/glucan ratio, and the smallest particle size (~70% of particles with mean diameter of 480 ± 33 nm). Structurally, these sub-micron particles demonstrated superior colloidal stability and a physical “barrier effect” for sustained hydration, outperforming the amorphous structures typically associated with mild extraction. The anti-wrinkle efficacy was validated through a specific “triad” mechanism: (1) the insoluble 3D network ensures prolonged water retention, (2) the particles exhibit robust free radical scavenging activity (~67%), and (3) most notably, the specific nano-structure significantly upregulated Collagen Type I-α1 expression in human dermal fibroblasts (HDF) and human skin fibroblasts (HSF), surpassing commercial chitin controls. These findings prove that the extraction-induced nano-structure, rather than mass yield, is the determinant factor for bioactivity, positioning S. cerevisiae CG as a high-performance, multi-target ingredient for anti-aging formulations. Full article

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16 pages, 1945 KB

Open AccessArticle

Frequencies, Velocities, and Spacing of Interfacial Waves of Falling Liquid Films in a Large Diameter Vertical Pipe

by Abbas H Hasan, Shara K Mohammed, Buddhika Hewakandamby, Faiza Saidj, Abdelwahid Azzi and Barry James Azzopardi

ChemEngineering 2026, 10(3), 32; https://doi.org/10.3390/chemengineering10030032 - 24 Feb 2026

Viewed by 461

Abstract

Many of the film thickness measurements that have been reported in the literature tend to focus on small pipe diameters, which may not be practical for a variety of industrial applications. Additionally, single-point measurements are unable to provide the necessary film thickness data [...] Read more.

Many of the film thickness measurements that have been reported in the literature tend to focus on small pipe diameters, which may not be practical for a variety of industrial applications. Additionally, single-point measurements are unable to provide the necessary film thickness data around the circumference of the pipe as well as in the axial direction. This paper aims to experimentally study the behaviour of wavy liquid films, including wave frequency, wave velocity, wave width, and wave spacing. A Multi-Pin Film Sensor (MPFS) was used to extract the thickness of a free-falling liquid film in axial, circumferential, and temporal coordinates. The range of liquid Reynolds number Re_L used was 618–1670. It was found that the power spectral density of the disturbance waves showed a pronounced peak at the modal frequency of 6–8 Hz. The number of disturbance waves was found to be almost independent of Re_L. The axial interfacial wave seemed to travel at a constant velocity while the mean velocity in circumferential direction was negligible. The mean width of the disturbance waves was approximately 17.7% of the pipe diameter. Full article

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ChemEngineering, Volume 10, Issue 3 (March 2026) – 11 articles

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