Processes

11 pages, 3070 KB

Open AccessArticle

Scale Deposits from Drinking-Water Pipelines as a Sustainable Heterogeneous Catalyst for Biodiesel Production

by Kaoutar Kara, Siham Bouzekri, Mohammed Zine, Fatiha Ouanji, Latifa Tajounte, Abdellah Benzaouak, Abdelilah Lahmar, Mohammed El Mahi, Mohamed Kacimi, El Mostapha Lotfi and Noureddine Touach

Processes 2026, 14(18), 2918; https://doi.org/10.3390/pr14182918 - 14 Sep 2026

Abstract

Biodiesel has attracted considerable attention as a promising renewable fuel because it burns cleaner than conventional diesel and produces lower pollutant emissions. In this work, a CaO-based heterogeneous catalyst was prepared by calcining drinking water pipeline scale deposits at 900 °C for 2 [...] Read more.

Biodiesel has attracted considerable attention as a promising renewable fuel because it burns cleaner than conventional diesel and produces lower pollutant emissions. In this work, a CaO-based heterogeneous catalyst was prepared by calcining drinking water pipeline scale deposits at 900 °C for 2 h. X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, thermogravimetric analysis (TG-DTA), atomic emission spectrometry ICP-AES, and scanning electron microscopy SEM were used to analyze all the solids. Characterization results revealed that the raw scale deposits mainly consisted of calcite (CaCO₃) containing trace amounts of metallic impurities. Catalytic activity was performed on a high-temperature calcined scale material. The effect of catalysts quantities, methanol to oil molar ratios, and reaction periods were researched in order to enhance the biodiesel’s quality. The obtained results showed that at 60 °C, the methyl ester content was 96% under transesterification conditions utilizing a catalyst concentration of 3%, a methanol/oil molar ratio of 12, and a reaction duration of 120 min. The produced biodiesel was also analyzed using FT-IR and NMR. Their properties were recorded according to the ASTM D6751 specifications of biodiesel and were discovered to be within the parameters. Full article

(This article belongs to the Special Issue High-Effective Energy Conversion for Sustainable Environment)

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35 pages, 12317 KB

Open AccessSystematic Review

Agentic Artificial Intelligence in Chemical Engineering, Process Systems Engineering, and Process Control: A Systematic Review of Emerging Perspectives and Challenges

by Anibal Alviz-Meza, Alejandro Valencia-Arias, Segundo Rojas-Flores and Félix Díaz

Processes 2026, 14(18), 2917; https://doi.org/10.3390/pr14182917 - 14 Sep 2026

Abstract

Agentic artificial intelligence is gaining significance in chemical engineering. Many process decisions involve coordinated actions rather than isolated predictions. These decisions are constrained by physical limitations, uncertain measurements, safety protocols, and human supervision. This PRISMA-guided systematic review asked where AI agents are applied [...] Read more.

Agentic artificial intelligence is gaining significance in chemical engineering. Many process decisions involve coordinated actions rather than isolated predictions. These decisions are constrained by physical limitations, uncertain measurements, safety protocols, and human supervision. This PRISMA-guided systematic review asked where AI agents are applied in chemical engineering and process control-related problems. It also asked which agent families are used, what evidence supports their contributions, and what limitations condition deployment. Scopus was searched in the title, abstract, and keyword fields on 20 April 2026. Eligible records were peer-reviewed articles published from 2022 to 2026, indexed in the Chemical Engineering subject area, and explicitly relevant to AI agents. Evidence maturity, reported limitations, and risk of overinterpretation were extracted for each study. The included studies were synthesized into four domains. These are safety and risk; digitalization and process systems engineering workflows; control, scheduling, and operations; and molecular, reaction, and materials design. Most evidence still comes from simulations, computational studies, or prototypes rather than from plants in operation. The review therefore identifies six conditions for deployment backed by auditable engineering evidence. These are industrial validation, safety guarantees, digital twins grounded in ontologies, reproducible evaluation of LLM agents, governance of the interaction between engineers and agents, and integration across scales. Full article

(This article belongs to the Special Issue Modeling and Optimization for Green Energy Materials: Machine Learning, Conventional, and Hybrid Approaches)

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19 pages, 12027 KB

Open AccessArticle

Mechanism of Ammonia Stripping Intensification via Jet Impact Under Vacuum: A Multi-Scale CFD Study on Vortex Evolution and Energy Dissipation

by Lingxing Hu, Zhongjun Li, Kuangbu Xiao, Lanfeng Guo and Facheng Qiu

Processes 2026, 14(18), 2916; https://doi.org/10.3390/pr14182916 - 14 Sep 2026

Abstract

Conventional air stripping for ammonia–nitrogen wastewater is often hampered by packing clogging and low mass transfer efficiency. To address these limitations, this study proposes a jet impact negative pressure reactor (JI-NPR) featuring an optimized scatter-pattern (D7) multi-orifice configuration. Computational Fluid Dynamics (CFD) simulations [...] Read more.

Conventional air stripping for ammonia–nitrogen wastewater is often hampered by packing clogging and low mass transfer efficiency. To address these limitations, this study proposes a jet impact negative pressure reactor (JI-NPR) featuring an optimized scatter-pattern (D7) multi-orifice configuration. Computational Fluid Dynamics (CFD) simulations were employed to systematically investigate the effects of Reynolds number (Re = 5503.4~9651.0, corresponding to 2.76~4.84 m/s) on the hydrodynamic characteristics and deamination performance. Results indicate that increasing jet velocity significantly enhances the water volume fraction, resultant velocity, and pressure core intensity within the impact zone. Notably, these enhancements are maximized at the second row (z = 146 mm), attributed to reduced interference from the negative-pressure flash evaporation region. While a higher Re promotes interfacial renewal and vortex evolution, thereby enhancing mass transfer, it also intensifies energy dissipation and reduces the uniformity of the turbulent kinetic energy distribution. This work elucidates a critical trade-off between mass transfer enhancement and energy consumption, establishing a quantitative structure: the Re–flow field-performance relationship. The findings provide a theoretical foundation for the design and optimization of energy-efficient, high-performance wastewater treatment systems. Full article

(This article belongs to the Topic Advanced Heat and Mass Transfer Technologies, 2nd Edition)

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20 pages, 2863 KB

Open AccessArticle

WF-MobileNet: A Lightweight Wavelet–Fusion Network for Classifying Defects in 3D Surface Morphology Images of Seamless Steel Pipes

by Xueyuan Wang, Xiaochen Wang, Quan Yang and Anrui He

Processes 2026, 14(18), 2915; https://doi.org/10.3390/pr14182915 - 14 Sep 2026

Abstract

Seamless steel pipes require reliable classification of outer-surface anomalies, yet class imbalance, scale variation, and visual overlap between defects and production interference complicate automated inspection. We propose WF-MobileNet for classifying two-dimensional RGB pseudo-colour surface morphology images derived from line-structured-light profiling. The model retains [...] Read more.

Seamless steel pipes require reliable classification of outer-surface anomalies, yet class imbalance, scale variation, and visual overlap between defects and production interference complicate automated inspection. We propose WF-MobileNet for classifying two-dimensional RGB pseudo-colour surface morphology images derived from line-structured-light profiling. The model retains MobileNetV3-Small as its primary descriptor path, applies Selective WTConv to selected middle- and late-stage depthwise operations, and aggregates features at three spatial resolutions through Lite-BiFPN. A gated residual connection adds the multiscale descriptor to the terminal backbone descriptor. Evaluation used 15,463 images covering 12 defect classes and 4 production interference classes, with five training seeds on one fixed partition. WF-MobileNet achieved the highest observed mean macro-F1 and interference F1 among the six evaluated architectures, reaching (82.17 ± 0.36)% and (80.50 ± 0.96)%, respectively (mean ± sample standard deviation). The corresponding gains over MobileNetV3-Small were 4.20 and 6.84 percentage points. With 1.811 million parameters and 65.8 million multiply–accumulate operations (MACs), WF-MobileNet ranked second lowest on both complexity measures. Controlled ablation revealed larger mean macro-F1 gains from the joint configuration than from either component alone. Within the evaluated archive, WF-MobileNet improved class-balanced recognition and defect–interference discrimination while retaining low parameter and MAC counts. Full article

(This article belongs to the Section AI-Enabled Process Engineering)

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20 pages, 8112 KB

Open AccessArticle

Geothermal Field Distribution Characteristics and Controlling Factors in the Moliqing Fault Depression, Yitong Basin

by Yihe Li, Yue Sun, Huanlai Zhu and Jiangping Gong

Processes 2026, 14(18), 2914; https://doi.org/10.3390/pr14182914 - 14 Sep 2026

Abstract

The Moliqing Fault Depression, located in the southwestern part of the Yitong Basin, is a Cenozoic strike–slip pull-apart basin controlled by the northern segment of the Tan-Lu Fault Zone. Based on measured formation temperature data from 41 wells and rock thermophysical property data [...] Read more.

The Moliqing Fault Depression, located in the southwestern part of the Yitong Basin, is a Cenozoic strike–slip pull-apart basin controlled by the northern segment of the Tan-Lu Fault Zone. Based on measured formation temperature data from 41 wells and rock thermophysical property data from 41 wells in the study area, terrestrial heat flow values were calculated using a one-dimensional steady-state heat conduction model. On this basis, temperature distribution maps at different depths, a terrestrial heat flow contour map, a formation temperature distribution map of the Shuangyang Formation, and well-to-well geothermal profiles were systematically constructed. The principal factors controlling the geothermal field were further investigated in terms of basement relief, basement lithology, and the spatial distribution of volcanic vents. The results indicate that the geothermal field in the study area exhibits pronounced lateral heterogeneity. Subsurface temperatures range from 39 to 66 °C at a depth of 1000 m, from 65 to 133 °C at 2000 m, and from 91 to 182 °C at 3000 m. The geothermal gradient ranges from 3.0 to 4.9 °C/100 m, with an average of approximately 3.6 °C/100 m. Terrestrial heat flow values range from 58 to 122 mW/m², averaging approximately 84 mW/m². Measurements of rock thermophysical properties show that thermal conductivity ranges from 1.9 to 2.7 W/(m·K), with an average of 2.3 W/(m·K). Radiogenic heat production ranges from 0.985 to 1.3 μW/m³, averaging 1.1 μW/m³. Well-to-well geothermal profiles indicate that basement relief exerts a strong control on the distribution of isotherms. The relatively high radiogenic heat production of the basement granites provides an important internal heat source for the geothermal field. Geothermal gradients increase markedly near volcanic vents, reflecting the perturbing effects of deep-seated thermal activity. These findings provide a scientific basis for hydrocarbon exploration and geothermal resource assessment in the Moliqing Fault Depression. Full article

(This article belongs to the Section Energy Systems)

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15 pages, 879 KB

Open AccessArticle

Multidimensional Analysis of Ore Spontaneous Combustion Tendency Based on IAHP and Improved Interval Approximation

by Huiling Xiong, Daobing Zhang, Ling Yan, Yang Zhang and Huadong Yin

Processes 2026, 14(18), 2913; https://doi.org/10.3390/pr14182913 - 14 Sep 2026

Abstract

To conduct a scientific and comprehensive analysis of the spontaneous combustion tendency of sulfide ores and improve the safety production level of sulfur mines, an indicator system for determining the spontaneous combustion tendency of sulfide ores and a comprehensive classification standard for the [...] Read more.

To conduct a scientific and comprehensive analysis of the spontaneous combustion tendency of sulfide ores and improve the safety production level of sulfur mines, an indicator system for determining the spontaneous combustion tendency of sulfide ores and a comprehensive classification standard for the spontaneous combustion tendency of sulfide ores were constructed. Based on this, a multidimensional information comprehensive analysis model for ore spontaneous combustion tendency was constructed by combining the interval analytic hierarchy process (IAHP) and the improved interval approximation analysis method. The interval judgment matrix was constructed by the interval analytic hierarchy process, and the weight of the spontaneous combustion tendency for evaluation indicators was calculated. By improving the interval approximation analysis, the indicators of the ore spontaneous combustion tendency were analyzed in the form of interval numbers, and the information potential was deeply explored to obtain multidimensional information such as the grade of the ore spontaneous combustion tendency and the reliability of the ore spontaneous combustion tendency, and then the comprehensive grade of the ore spontaneous combustion tendency was determined. By using this model, a multidimensional information analysis was conducted on the spontaneous combustion tendency of each ore layer in a certain sulfur iron mine, with the indicators of the ore spontaneous combustion tendency as the interval number. It was found that the 30-day oxidation weight gain rate exerts the most significant influence on ore spontaneous combustion. The ore in ore layer no. 1 was prone to spontaneous combustion with relatively reliable results, while the ores in ore layers no. 2 and 3 were susceptible to self-heating with highly reliable results. This study provides a reference and guidance for the targeted prevention of ore spontaneous combustion in the mine. Full article

(This article belongs to the Section Process Safety and Risk Management)

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16 pages, 3723 KB

Open AccessArticle

Mineralogical and Surface Responses During CO₂–Synthetic Formation Water–Granitic Gneiss Interaction in Bohai Buried-Hill Reservoirs

by Guangyu Shi, Jiacheng Dai, Yanzun Li, Yuqing Ma, Yujia Liu and Yiwen Guo

Processes 2026, 14(18), 2912; https://doi.org/10.3390/pr14182912 - 14 Sep 2026

Abstract

Offshore buried-hill reservoirs are potential targets for integrated CO₂-enhanced oil recovery and geological storage. However, the early-stage response of clay-rich granitic gneiss under reservoir conditions remains poorly constrained. We conducted 7-day static experiments with an illite-rich mineral powder assemblage at 125 [...] Read more.

Offshore buried-hill reservoirs are potential targets for integrated CO₂-enhanced oil recovery and geological storage. However, the early-stage response of clay-rich granitic gneiss under reservoir conditions remains poorly constrained. We conducted 7-day static experiments with an illite-rich mineral powder assemblage at 125 °C and 35 or 50 MPa using synthetic formation water. Complementary granitic gneiss discs were reacted at 50 MPa for surface observations. The powders were characterized by XRD, FTIR, and XPS and the discs by SEM–EDS. XRD indicated lower relative abundances of illite after reaction and more pronounced changes in several carbonate and clay phases at 50 MPa. FTIR showed the attenuation of structural O–H, carbonate, and aluminosilicate-related bands, while XPS indicated surface elemental redistribution. SEM–EDS revealed mineral-selective surface alteration and localized particle accumulation. Quartz appeared less reactive than clay minerals and calcite over the experimental duration. The particles may include redeposited fines or secondary products, but their phase identity remains unresolved. Together, the observations characterize early-stage mineralogical and surface responses relevant to evaluating CO₂–rock interactions in clay-rich buried-hill reservoirs. Their consequences for injectivity and long-term storage require direct petrophysical and geomechanical evaluation. Full article

(This article belongs to the Section Petroleum and Low-Carbon Energy Process Engineering)

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31 pages, 3257 KB

Open AccessArticle

Investigation on the Influence Mechanisms of Temperature and SARA Composition on the Wax Precipitation and Wax Crystal Micromorphology in Condensate Systems

by Xiaoying Yang, Hongjun Wu, Jianxin Shen, Yuanwu Dong, Wenming Yang, Haixia Xu, Chunhai Gao, Yuzhuang Liu and Chao Zhang

Processes 2026, 14(18), 2911; https://doi.org/10.3390/pr14182911 - 13 Sep 2026

Abstract

In this study, three compositionally distinct condensate systems were tested to explore wax precipitation behaviors under variable temperature conditions. Multiple experimental approaches, including isothermal centrifugation for solid–liquid separation, gas chromatographic component quantification, SARA fractionation, and microscopic morphological observation, were comprehensively employed to investigate [...] Read more.

In this study, three compositionally distinct condensate systems were tested to explore wax precipitation behaviors under variable temperature conditions. Multiple experimental approaches, including isothermal centrifugation for solid–liquid separation, gas chromatographic component quantification, SARA fractionation, and microscopic morphological observation, were comprehensively employed to investigate the temperature-dependent evolution of wax-precipitation mass fraction, precipitation rate, precipitate composition, and crystal microstructure. On this basis, the coupled effects of temperature and fluid composition on wax-dominated precipitation behaviors were systematically analyzed. The results indicate that temperature decline can reduce system internal energy and decrease the nucleation energy barrier of wax crystals. Such variations facilitate the precipitation of wax components and weaken the Brownian motion of newly formed solid particles, thereby simultaneously increasing the waxy precipitate mass fraction and precipitation rate. The compositional characterization of wax precipitates formed at different temperatures confirms that saturated hydrocarbons may serve as the predominant wax-forming component, and their abundance governs the final precipitation yield of the system in this study. Statistical analysis of the experimental data indicates that the proportion of precipitated-wax mass to the total wax content in the system rises with the increase in the asphaltene-to-resin content ratio. This indicates that asphaltenes may provide nucleation sites for wax-crystal growth and thereby facilitate wax precipitation, whereas resins could encapsulate crystal nuclei and produce a steric-hindrance effect to exert a certain inhibitory effect on wax-crystal precipitation. Furthermore, owing to differences in the solubilities of components with varying carbon numbers, low-carbon-number alkanes become prone to precipitate gradually as their precipitation conditions are satisfied during cooling. This corresponds to an increase in their proportion within precipitates, shifting the peak of the carbon-number-distribution curve of precipitates toward the low-carbon-number region and altering the SARA composition of systems. At the microscopic scale, the proportion of macrocrystalline wax crystals in precipitates increases as the temperature decreases, accompanied by an enlargement in the average wax-crystal size, which is consistent with the aforementioned rise in low-carbon-number-alkane content. This study aims at providing experimental data and theoretical support for evaluating the development and composition of wax precipitates at different wellbore conditions to a certain extent. Full article

(This article belongs to the Special Issue Advanced Strategies in Enhanced Oil Recovery: Theory and Technology)

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25 pages, 6885 KB

Open AccessArticle

Reagent-Assisted Phytoextraction Potential for Heavy and Critical Metals on a Contaminated Post-Mining Substrate as NBS

by Petar Petrov, Veneta Stefanova, Yana Daskalova, Ekaterina Todorova, Iva Miteva and Elitsa Mihailova

Processes 2026, 14(18), 2910; https://doi.org/10.3390/pr14182910 - 13 Sep 2026

Abstract

Restoring contaminated and degraded land, including post-mining sites, industrial areas, and urban brownfields, is central to sustainable land management, and nature-based solutions (NBSs) such as phytoextraction can combine soil remediation with wider landscape-restoration goals. This screening-stage pot study evaluated how three mobilising agents, [...] Read more.

Restoring contaminated and degraded land, including post-mining sites, industrial areas, and urban brownfields, is central to sustainable land management, and nature-based solutions (NBSs) such as phytoextraction can combine soil remediation with wider landscape-restoration goals. This screening-stage pot study evaluated how three mobilising agents, potassium iodide (KI), calcium chloride (CaCl₂), and ammonium chloride (NH₄Cl), applied at 20, 50, and 80 mg kg⁻¹ against a common citric-acid background, affect the uptake and translocation of 27 potentially toxic elements and critical raw materials in Brassica juncea and Cichorium intybus grown on a met-al-contaminated post-mining substrate from Srednogorie, Bulgaria, which is used as a model of severely degraded technogenic material relevant to industrial and urban brownfield conditions. Bioconcentration and translocation factors were calculated from XRF measurements of the substrate, root, and leaf tissue and examined descriptively with exploratory principal component analysis and clustering, since each combination was one composite sample. Plant species identity, rather than reagent, was the strongest determinant of accumulation: Brassica juncea more often retained Y, Sr, Th, and Zn in roots, whereas C. intybus translocated Rb, Sr, Pb, and Cu more readily to leaves. KI produced the most distinct profile, increasing root and, at the highest dose, shoot enrichment of V, whereas CaCl₂ and NH₄Cl mainly enhanced root retention with limited, non-monotonic effects on shoot transfer. These species- and element-specific strategies indicate screening-stage potential for phytoextraction, pending validation with replicated biomass and yield data. Full article

(This article belongs to the Special Issue Advances in Heavy Metal Contaminated Soil and Water Remediation)

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21 pages, 3677 KB

Open AccessArticle

Axial Stress Prediction and Collapse Resistance Calculation of Tubing in CCUS Injection Wells

by Wei Luo, Lixue Guo, Xueqiang Wang, Jinlong Wang, Zichen Zou, Zihan Ma, Wei Xiong and Wei Yan

Processes 2026, 14(18), 2909; https://doi.org/10.3390/pr14182909 - 13 Sep 2026

Abstract

This study investigates tubing collapse resistance during low-temperature dense-phase CO₂ injection in carbon capture, utilization, and storage (CCUS) wells. A coupled temperature–pressure–tubing mechanics–collapse model was developed. CO₂ density, specific enthalpy, isobaric heat capacity, and the Joule–Thomson coefficient were calculated using the [...] Read more.

This study investigates tubing collapse resistance during low-temperature dense-phase CO₂ injection in carbon capture, utilization, and storage (CCUS) wells. A coupled temperature–pressure–tubing mechanics–collapse model was developed. CO₂ density, specific enthalpy, isobaric heat capacity, and the Joule–Thomson coefficient were calculated using the Span–Wagner equation of state, while wellbore temperature and pressure profiles were obtained from mass, momentum, and energy conservation equations. Tubing axial stress and triaxial collapse resistance were evaluated considering self-weight, thermal effects, ballooning, and fluid friction. Comparison with multi-depth measurements from one injection well produced bottomhole temperature and pressure errors of 0.99% and 0.71%, respectively. Sensitivity analysis showed that each 5 °C decrease in injection temperature reduced collapse resistance by approximately 2% on average. Each 5 MPa increase in injection pressure reduced it by only approximately 0.3% because the resulting combined-stress change was small relative to the tubing yield strength and the thermal contribution remained nearly unchanged. Increasing injection rate shortened heat-exchange time, lowered fluid temperature, and increased tubing loads, but had a weaker influence than injection temperature. The model provides a basis for optimizing injection parameters and verifying tubing strength. Full article

(This article belongs to the Topic Carbon Capture, Storage and Utilisation Technologies (CCS/CCU)—3rd Edition)

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23 pages, 10455 KB

Open AccessArticle

From Agricultural Waste to Food Safeguard: Coffee Shell-Derived Carbon Dots with Antibacterial Activity for Fruit Freshness Extension

by Ziyu Tang, Hanyan Shi, Wenjie Huang, Zhunjie Li, Ling Wang, Mengxi Cao and Fang Ji

Processes 2026, 14(18), 2908; https://doi.org/10.3390/pr14182908 - 13 Sep 2026

Abstract

Postharvest bacterial spoilage poses a major threat to global food safety, which is particularly prominent for fruits with high moisture and nutrient contents. Hence, environmentally friendly and efficient antibacterial solutions are urgently needed. Carbon dots (CDs) exhibit promising antibacterial potential in fruit preservation. [...] Read more.

Postharvest bacterial spoilage poses a major threat to global food safety, which is particularly prominent for fruits with high moisture and nutrient contents. Hence, environmentally friendly and efficient antibacterial solutions are urgently needed. Carbon dots (CDs) exhibit promising antibacterial potential in fruit preservation. Upon screening, coffee-husk-derived carbon dots (CS-CDs) were identified to possess highly efficient antibacterial activity. In this work, CS-CDs were synthesized via a one-step hydrothermal method. The as-prepared CS-CDs have an average particle size of 2.0 nm, and their surfaces are rich in carboxyl, hydroxyl and amino groups, delivering distinct photoresponsive capacity. Antibacterial assays reveal that the inhibitory rates of CS-CDs against Escherichia coli and Staphylococcus aureus both exceed 95%. The bactericidal effect is mainly realized by reactive oxygen species and physical contact, which disrupt bacterial cell membranes and trigger cellular damage. Meanwhile, CS-CDs are verified to possess favorable biosafety for practical application. Finally, CS-CDs were successfully incorporated into carboxymethyl cellulose (CMC) to fabricate CS-CDs/CMC composite films with superior mechanical properties compared with pure CMC films. Film-property analyses demonstrate their suitability for fresh-fruit preservation packaging. Continuous monitoring and analysis of fruit quality during litchi and mango storage confirm the preservation and anti-spoilage performance of the composite film. This study provides a promising alternative to conventional synthetic preservatives and metal-ion-based antibacterial agents, offering advantages of environmental friendliness, high antibacterial efficiency, favorable biocompatibility, and reliable biosafety. Meanwhile, it provides a feasible strategy for the design and application of biomass-based antibacterial preservation-packaging materials. Full article

(This article belongs to the Section Food Process Engineering)

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20 pages, 6205 KB

Open AccessArticle

Numerical Simulation Study on the Combustion of Coal Powder in Swirl Burners with Different Ammonia Blending Ratios

by Jiaqi Li and Hao Lu

Processes 2026, 14(18), 2907; https://doi.org/10.3390/pr14182907 - 13 Sep 2026

Abstract

To promote carbon reduction in existing coal-fired power units while ensuring stable operation, ammonia–coal co-firing has attracted increasing attention as a promising low-carbon combustion technology. This study developed a three-dimensional numerical model for a single swirl-stabilized pulverized-coal burner to investigate ammonia–coal co-firing under [...] Read more.

To promote carbon reduction in existing coal-fired power units while ensuring stable operation, ammonia–coal co-firing has attracted increasing attention as a promising low-carbon combustion technology. This study developed a three-dimensional numerical model for a single swirl-stabilized pulverized-coal burner to investigate ammonia–coal co-firing under a constant total fuel heating input. The model was validated against reference measurements, with relative deviations of 2.97% for nitrogen oxide concentration and 2.92% for burnout rate. The effects of ammonia co-firing on flame characteristics, combustion performance, and species distribution were then evaluated. As the ammonia blending ratio increased from 0% to 20%, the peak furnace temperature decreased from 1597.35 to 1389.82 K, while the high-temperature region contracted. At the centerline end, the carbon dioxide molar fraction decreased from 16.46% to 12.03%, corresponding to a 26.9% reduction. Nitrogen oxide concentrations were lower near the burner but increased downstream after secondary-air mixing; the highest downstream concentration was 544.86 mg/Nm³ under a 15% ammonia blending condition. The present study clarifies how co-firing of ammonia with pulverized coal affects in-furnace temperature and combustion-species distributions in a swirl pulverized-coal burner, providing an engineering basis for low-carbon retrofits of existing coal-fired power units. Full article

(This article belongs to the Section Energy Systems)

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20 pages, 3844 KB

Open AccessArticle

Improving the Active Function of Polylactic Acid (PLA) Packaging Films Coated by Pectin Layers Enhanced with Gallic Acid

by Anna Łyczak, Anna Pakulska and Sabina Galus

Processes 2026, 14(18), 2906; https://doi.org/10.3390/pr14182906 - 13 Sep 2026

Abstract

This study investigated the feasibility of imparting active functions to commercial polylactic acid (PLA) packaging films through a coating process and the resulting impact on pasteurized milk quality. PLA films were coated with citrus or apple pectin film-forming solutions, plasticized with glycerol, and [...] Read more.

This study investigated the feasibility of imparting active functions to commercial polylactic acid (PLA) packaging films through a coating process and the resulting impact on pasteurized milk quality. PLA films were coated with citrus or apple pectin film-forming solutions, plasticized with glycerol, and enriched with gallic acid. The effects of this coating on the thickness, optical, barrier, structural, wetting, and antioxidant properties of the PLA films were examined. The thickness of the coated films increased from 30.0 to 61.3 µm and their visual surface roughness increased, while the addition of gallic acid significantly improved their UV-VIS light-barrier capacity and antioxidant activity against ABTS and DPPH radicals. Color analysis revealed a decrease in film lightness (the L* parameter decreased from 91.0 to 90.2 after modification with apple pectin-based coatings) and a color shift toward green (negative a* parameter) and yellow (positive b* parameter). The total color difference measured using the control PLA film (uncoated PLA) as a reference was significantly lower for coated samples based on citrus pectin (0.3–0.5) than those based on apple pectin (1.6–1.7), with no significant effect of the addition of phenolic acid. The water vapor permeability of the PLA films increased from 6.8 ∙ 10⁻¹¹ g∙m⁻¹∙s⁻¹∙Pa⁻¹ to 8.2–9.4 ∙ 10⁻¹¹ g∙m⁻¹∙s⁻¹∙Pa⁻¹ and 10.1–10.6 ∙ 10⁻¹¹ g∙m⁻¹∙s⁻¹∙Pa⁻¹ for samples coated with apple and citrus pectin without and with gallic acid, respectively. However, the oxygen permeability of PLA films significantly decreased from 30.7 ∙ 10⁻¹⁶ g∙m⁻¹∙s⁻¹∙Pa⁻¹ to 0.4–0.8 ∙ 10⁻¹⁶ g∙m⁻¹∙s⁻¹∙Pa⁻¹ for coated samples. This tendency aligned with the results of carbon dioxide permeability, which was reduced from 39.1 ∙ 10⁻¹⁶ g∙m⁻¹∙s⁻¹∙Pa⁻¹ to 0.7–0.9 ∙ 10⁻¹⁶ g∙m⁻¹∙s⁻¹∙Pa⁻¹ for coated films. Water contact angle measurement showed the hydrophilic nature of all PLA samples (contact angles less than 90°). The application of analyzed control and coated PLA packaging films slowed milk souring during storage, as evidenced by reduced quality changes and delayed curd formation. The application of PLA coated with apple pectin containing gallic acid, as well as citrus pectin with or without gallic acid, resulted in the lowest pH changes after 8 days of storage (6.6 and 6.7), demonstrating the superior efficacy of these films in maintaining milk quality. Full article

(This article belongs to the Special Issue Towards Advanced and Sustainable Bio-Based Materials for Green Technologies)

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35 pages, 11017 KB

Open AccessArticle

Dynamic Calibration of the Wellbore Temperature Field Based on Nonlinear Moving Horizon Estimation

by Zhuoran Meng, Zhen Wang, Shixuan Yin, Shuo Yang, Baochang Xu and Qingfeng Guo

Processes 2026, 14(18), 2905; https://doi.org/10.3390/pr14182905 - 12 Sep 2026

Abstract

During drilling circulation, the wellbore temperature field changes in response to drilling-fluid rheology, borehole geometry, drillstring eccentricity, and cuttings concentration. Conventional wellbore temperature models use fixed heat-transfer parameters and therefore cannot accurately represent real-time heat-transfer conditions. To address this limitation, a transient temperature [...] Read more.

During drilling circulation, the wellbore temperature field changes in response to drilling-fluid rheology, borehole geometry, drillstring eccentricity, and cuttings concentration. Conventional wellbore temperature models use fixed heat-transfer parameters and therefore cannot accurately represent real-time heat-transfer conditions. To address this limitation, a transient temperature model was developed. Bottomhole annular-fluid temperatures generated by OLGA were used as synthetic observations for MHE calibration. An MHE-based calibration method was developed to estimate the equivalent heat-transfer correction factor. The temperature model was first benchmarked against the Kabir analytical model and the commercial simulator OLGA. The estimated correction factor was then used by the mechanistic model to update the wellbore temperature field. The results showed that, under different initial values of the correction factor and assumed measurement-noise standard deviations, the equivalent heat-transfer correction factor converged to a steady-state value of approximately 0.941. Additional sensitivity tests showed generally stable calibration performance under moderate parameter settings, whereas stronger observation noise reduced calibration stability and accuracy. Under varying operating conditions, the calibrated bottomhole temperature yielded a mean absolute error of 0.033–0.332 °C, representing a reduction of 45.97–98.73% relative to the corresponding uncalibrated results. When the observation delay was extended to 2400 s (d = 8), the MAE was still reduced by 26.50–68.20% across different operating stages. These numerical results show that the proposed method can use bottomhole temperature observations to dynamically compensate for equivalent heat-transfer model mismatch under the investigated simulation conditions. The method reduces model-prediction errors and improves bottomhole temperature prediction under the tested varying operating conditions. The proposed method has potential applications in wellbore temperature prediction and high-temperature risk assessment for deep-well drilling. Full article

(This article belongs to the Special Issue Advances in Cutting-Edge Drilling Technology)

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32 pages, 432 KB

Open AccessFeature PaperArticle

Interpretable Evidence Fusion for Controlled Fraud-Episode Screening in Advanced Metering Infrastructure

by Javier E. Duarte, Rodolfo Garcia Sierra and Javier Rosero-Garcia

Processes 2026, 14(18), 2904; https://doi.org/10.3390/pr14182904 - 12 Sep 2026

Abstract

Non-technical losses are difficult to identify from Advanced Metering Infrastructure (AMI) data because fraud has different physical signatures, communication failures can resemble manipulation, and field-confirmed labels are scarce. This paper proposes an evidence-fusion methodology that transforms hourly consumption into traceable inspection events. The [...] Read more.

Non-technical losses are difficult to identify from Advanced Metering Infrastructure (AMI) data because fraud has different physical signatures, communication failures can resemble manipulation, and field-confirmed labels are scarce. This paper proposes an evidence-fusion methodology that transforms hourly consumption into traceable inspection events. The method verifies reading provenance, estimates expected profiles from previous observations, evaluates mechanism-specific experts, and consolidates persistent detections under fixed inspection capacity. Because no open hourly AMI dataset with field-confirmed fraud dates was identified, evaluation used controlled episodes on real consumption backgrounds and TDD2022, an open benchmark with synthetic theft events. In a user-disjoint controlled cohort, the policy detected 108 of 150 episodes within seven days (recall 0.720), 17 more than the reference workflow (exact McNemar

p = 0.0115

). On TDD2022, evidence fusion obtained a recall of 0.689, a precision of 0.998, an F1 score of 0.816, and an area under the precision–recall curve (PR–AUC) of 0.928, with two false alerts among 2455 normal days. The results show that causal and mechanism-specific evidence can produce a capacity-aware inspection list across two controlled benchmarks. Field inspections remain necessary to estimate diagnostic accuracy. Full article

(This article belongs to the Special Issue Design and Optimisation of Solar Energy Systems)

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25 pages, 2390 KB

Open AccessArticle

Evaluation of Lithium-Ion Battery Effectiveness Using a Novel Hybrid Multi-Criteria Decision-Making Approach

by Hakan Ayhan Dağıstanlı, Alpaslan Atmanli and Nadir Yilmaz

Processes 2026, 14(18), 2903; https://doi.org/10.3390/pr14182903 - 12 Sep 2026

Abstract

The most important factor affecting the power and efficiency of electric vehicles is the configuration of the cathode active materials in lithium-ion batteries (LIBs). Selecting this configuration chemistry requires a comprehensive evaluation of the effectiveness of LIB technologies and the establishment of a [...] Read more.

The most important factor affecting the power and efficiency of electric vehicles is the configuration of the cathode active materials in lithium-ion batteries (LIBs). Selecting this configuration chemistry requires a comprehensive evaluation of the effectiveness of LIB technologies and the establishment of a decision-making framework. For this purpose, this study examines eight different battery technologies using six criteria that influence the selection of batteries currently in use. In this context, the criteria were weighted using the simple weight calculation (SIWEC) method. Alternative technologies were then ranked using the Alternative Ranking Technique based on Adaptive Standardized Intervals (ARTASI) method. The robustness of the results was then investigated by conducting parameter analyses and comparisons with other multi-criteria decision-making (MCDM) techniques to determine the effectiveness of this new MCDM integration. A compromise solution was proposed by using swap calculations using the Dodgson method to aggregate the different results. Consequently, Lithium Iron Phosphate (LFP) was determined as the most superior battery chemistries, followed by Lithium Nickel Manganese Cobalt Oxide (NMC) and Lithium Titanate (LTO)-based LIB, and Lithium Cobalt Oxide (LCO) ranked last. The proposed methodology aims to minimize the uncertainty arising from subjective expert evaluations and to integrate different ranking outcomes within a unified decision-making framework. This integration enables the alternatives to be evaluated from both criterion-based and majority-based perspectives, allowing different aspects of the decision outcomes to be considered simultaneously. Full article

(This article belongs to the Special Issue Recent Advances in Energy and Dynamical Systems)

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18 pages, 3302 KB

Open AccessArticle

Optimization of the Quenching Process in Insoluble Sulfur Production Based on Steady-State Process Simulation and Orthogonal Design

by Haibo Liu, Weizhao Yu, Kai Chen and Weiwei Xu

Processes 2026, 14(18), 2902; https://doi.org/10.3390/pr14182902 - 12 Sep 2026

Abstract

This study focuses on optimizing the quenching process for insoluble sulfur (IS) production, addressing the issues of high energy consumption and poor safety associated with the existing vaporization method. A process simulation model for a pilot-scale reactor was established using Aspen Plus V11. [...] Read more.

This study focuses on optimizing the quenching process for insoluble sulfur (IS) production, addressing the issues of high energy consumption and poor safety associated with the existing vaporization method. A process simulation model for a pilot-scale reactor was established using Aspen Plus V11. The research specifically investigated the influence patterns of three key parameters—the inlet temperature of the circulating liquid, the carbon-disulfide-to-sulfur (CS₂/S) mass ratio, and the mass ratio of circulating liquid to sulfur vapor—on the quenching effectiveness. Unlike previous Aspen Plus studies mainly directed toward overall IS production and recovery processes, the present work focuses specifically on the pilot-scale quenching stage and integrates single-factor thermodynamic analysis with a simulation-based orthogonal design to quantitatively rank the effects of the circulating liquid operating parameters. The orthogonal analysis showed that the mass feed ratio of circulating liquid to sulfur vapor was the dominant factor affecting the mixed temperature, followed by the circulating liquid inlet temperature, whereas the CS₂/S mass ratio had a comparatively smaller influence. Based on the simulated quenching behavior and thermodynamic constraints, the proposed process-level operating conditions were a CS₂:S mass ratio of 86:14–88:12, a circulating liquid inlet temperature of 50–56 °C, and a circulating liquid-to-sulfur vapor mass ratio of no less than 260:1. These results provide quantitative guidance for the steady-state optimization of the pilot-scale quenching process. Full article

(This article belongs to the Special Issue Process Engineering: Process Design, Control, and Optimization)

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23 pages, 4957 KB

Open AccessFeature PaperArticle

Crystallographic Fingerprints of Thermal Textile Residues: Insights into Material Origin and Thermal Treatment Conditions from X-Ray Powder Diffraction and SEM–EDX

by Domenica Marabello, Federica Pau and Paola Benzi

Processes 2026, 14(18), 2901; https://doi.org/10.3390/pr14182901 - 12 Sep 2026

Abstract

Thermal degradation of textile materials produces complex residues whose characterization can provide information on both the original material and the conditions experienced during heating. This study investigates the potential of X-ray Powder Diffraction (XRPD) as a complementary approach for the characterization of textile [...] Read more.

Thermal degradation of textile materials produces complex residues whose characterization can provide information on both the original material and the conditions experienced during heating. This study investigates the potential of X-ray Powder Diffraction (XRPD) as a complementary approach for the characterization of textile thermal residues and for evaluating whether crystallographic features can retain information on textile composition and thermal exposure conditions. Twenty-five commercial textile samples, including natural fibres (cotton and silk) and synthetic polyester-based fabrics, were characterized before and after controlled thermal treatments at 400 and 800 °C under air and a modified atmosphere containing 10% O₂. The untreated fabrics exhibited characteristic diffraction patterns related to their fibre composition, whereas the residues showed significant changes depending on both the original textile and the treatment conditions. Higher-temperature treatments produced more crystalline residues, allowing improved discrimination among different textile categories. Differences between air and oxygen-limited conditions were also reflected in the diffraction patterns, indicating that oxygen availability influences the evolution of crystalline phases during thermal degradation. SEM–EDX analyses supported the interpretation of the diffraction data, although several residues showed complex patterns that prevented unambiguous phase identification. Overall, the results indicate that XRPD can provide valuable complementary information on the crystallographic evolution of textile thermal residues and may contribute to the characterization of textile composition and thermal exposure conditions. Full article

(This article belongs to the Special Issue Women’s Special Issue Series: Processes)

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13 pages, 2809 KB

Open AccessArticle

Hydrothermal Synthesis of a Nickel(II) Phosphinate Coordination Material and Its Integration into a PVC Membrane for Potentiometric Naloxone Detection

by Diana Anghel, Dana Vlascici, Bianca-Denisa Cernușcă, Vlad Chiriac and Gheorghe Ilia

Processes 2026, 14(18), 2900; https://doi.org/10.3390/pr14182900 - 12 Sep 2026

Abstract

A nickel(II) coordination material derived from 2-carboxyethyl(phenyl)phosphinic acid (CEPPA) was obtained under hydrothermal conditions and investigated by elemental analysis, Fourier-Transform Infrared spectroscopy (FT-IR), Scanning Electron Microscopy coupled with Energy-Dispersive X-ray analysis (SEM/EDX), Thermogravimetric Analysis (TGA), and Powder X-ray Diffraction (PXRD). Indexing and powder-profile [...] Read more.

A nickel(II) coordination material derived from 2-carboxyethyl(phenyl)phosphinic acid (CEPPA) was obtained under hydrothermal conditions and investigated by elemental analysis, Fourier-Transform Infrared spectroscopy (FT-IR), Scanning Electron Microscopy coupled with Energy-Dispersive X-ray analysis (SEM/EDX), Thermogravimetric Analysis (TGA), and Powder X-ray Diffraction (PXRD). Indexing and powder-profile refinement of the PXRD data support a monoclinic crystalline phase. FT-IR data are consistent with ligand deprotonation and changes in the phosphinate/carboxylate environments upon reaction with Ni(II), without assigning a unique coordination mode from vibrational data alone. The material was incorporated into a PVC/o-NPOE membrane containing NaTPB and evaluated for potentiometric naloxone detection. A linear response was obtained over 10⁻²–10⁻⁵ M with a slope of 52.67 mV decade⁻¹ and an experimental detection limit of 8.5 × 10⁻⁶ M. The results demonstrate the feasibility of integrating the Ni(II)–CEPPA material into a polymeric sensing membrane, while definitive atomic-level structural assignment and specific recognition interactions require additional structural and mechanistic evidence. Full article

(This article belongs to the Section Materials Processes)

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