Processes

19 pages, 8220 KB

Open AccessArticle

Separation of Glycerides from Algal Lipid Extract Using Preparative Chromatography

by Costas Tsioptsias, Fotios Safarikas, Konstantina Triantafyllou, Maja Berden Zrimec, Sotirios Kalamaras and Petros Samaras

Processes 2026, 14(17), 2854; https://doi.org/10.3390/pr14172854 (registering DOI) - 6 Sep 2026

Abstract

Crude vegetable oils contain, in addition to glycerides, a range of co-extracted compounds whose composition depends strongly on the biological source. Their removal typically requires multi-stage refining, increasing process complexity as well as solvent and energy demands. In this study, a simple preparative [...] Read more.

Crude vegetable oils contain, in addition to glycerides, a range of co-extracted compounds whose composition depends strongly on the biological source. Their removal typically requires multi-stage refining, increasing process complexity as well as solvent and energy demands. In this study, a simple preparative chromatographic method was developed to purify crude algal lipid extracts and recover a glyceride-rich fraction. The process employed hexane as the mobile phase and cellulose-based materials as the stationary phase. The underlying separation mechanism was investigated experimentally using paper chromatography, thin-layer chromatography (TLC), and Fourier transform infrared spectroscopy (FTIR), and was further interpreted using Hansen solubility parameters (HSPs). Approximately 50% of the crude lipid extract was recovered as a glyceride-rich, colorless fraction. A secondary fraction enriched in sterols, chlorophylls, and carotenoids were also recovered, highlighting the potential for simultaneous purification and recovery of valuable lipid-associated compounds. To support potential process scale-up, regeneration of the stationary phase was evaluated, with each cycle required 0.225 L of fresh hexane and 0.1 L of fresh methanol. In addition, low-cost cellulose-rich residues, including used paperboard and wood dust, were successfully validated as alternative stationary phase materials. Overall, the proposed process provides a straightforward and potentially scalable approach to refining algal lipid extracts while enabling the recovery of additional value-added fractions and the use of inexpensive cellulose-based materials. Full article

(This article belongs to the Special Issue Advanced Biofuel Production Processes and Technologies)

16 pages, 12760 KB

Open AccessArticle

Molecular Dynamics Study on the Effect of Calcite Deposition on the Interfacial Bonding Performance Between Shotcrete and Surrounding Rock

by Qian Weng, Sipeng Liao, Biao Huang, Shiyang Liu, Liang Cheng and Yugang Cheng

Processes 2026, 14(17), 2853; https://doi.org/10.3390/pr14172853 (registering DOI) - 6 Sep 2026

Abstract

During the service life of karst tunnels, groundwater containing Ca²⁺ and CO₃²⁻ can migrate along the shotcrete–surrounding rock interface and induce calcite deposition, thereby changing the interfacial material composition and load transfer path. To clarify the effect of this process [...] Read more.

During the service life of karst tunnels, groundwater containing Ca²⁺ and CO₃²⁻ can migrate along the shotcrete–surrounding rock interface and induce calcite deposition, thereby changing the interfacial material composition and load transfer path. To clarify the effect of this process on interfacial bonding performance, this study used molecular dynamics simulations to construct CSH–SiO₂, SiO₂–calcite, CSH–calcite, and CSH–calcite–SiO₂ interface models. The interfacial density distribution, radial distribution function, number of hydrogen bonds, interaction energy, and normal tensile failure behavior were analyzed. The results show that all four models reached stable energy plateaus after relaxation, and clear atomic density overlap and short-range RDF peaks appeared in the interfacial regions. These descriptors indicate short-range contact and possible Ca–O electrostatic attraction, hydroxyl-related hydrogen bonding, and carbonate-associated interactions between calcite and both SiO₂ and CSH surfaces. Approximately 80 hydrogen bonds were formed at the SiO₂–calcite interface, approximately 32 at the CSH–calcite interface, and approximately 59 in total for the two hydrogen bond subtypes at the SiO₂–CSH interface, indicating that the hydroxyl state of different substrate surfaces controls the interfacial hydrogen bond network. Interaction energy analysis shows that the single CSH–calcite interface has the strongest interaction (−51,753.6 kcal/mol), approximately 1.90 times that of the SiO₂–CSH interface and 16.43 times that of the SiO₂–calcite interface. However, in the three-layer composite model, the interaction energy on the CSH–calcite side is only approximately 28.0% of that on the SiO₂–calcite side, suggesting that a continuous calcite interlayer introduces asymmetric interfacial constraints. Tensile simulations further show that the SiO₂–calcite model has the highest peak stress (approximately 3.23 GPa) and exhibits brittle failure, whereas failure in CSH-containing systems is more likely to transfer into the CSH layer or weakly connected regions. These results indicate that calcite deposition does not simply strengthen or weaken the interface. Instead, within the two idealized endpoint configurations tested here, its effect depends on deposition continuity, the surface chemistry of the two substrates, and the weak links within the serial interface. This study provides a nanoscale theoretical basis for evaluating relative trends in the long-term service performance of shotcrete–surrounding rock interfaces, and for guiding future multiscale validations of drainage and waterproofing measures in karst tunnels. Full article

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

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24 pages, 1617 KB

Open AccessArticle

Tailored Nutrient Feeding Strategies for mcl-PHA Production and Molecular Weight Regulation in Pseudomonas putida

by Giannis Penloglou, Alexandros Pavlou, Katerina Foka, Evangelos Topakas and Christos Chatzidoukas

Processes 2026, 14(17), 2852; https://doi.org/10.3390/pr14172852 (registering DOI) - 5 Sep 2026

Abstract

Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) are biodegradable microbial polyesters with attractive elastomeric properties and considerable potential as sustainable alternatives to fossil-derived polymers. Their industrial production requires not only efficient biomass and biopolymer productivity but also consistent material quality. In this study, Pseudomonas putida KT2442 was [...] Read more.

Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) are biodegradable microbial polyesters with attractive elastomeric properties and considerable potential as sustainable alternatives to fossil-derived polymers. Their industrial production requires not only efficient biomass and biopolymer productivity but also consistent material quality. In this study, Pseudomonas putida KT2442 was cultivated under different nutrient conditions to evaluate the effects of carbon, nitrogen, phosphorus and magnesium supplementation on biomass growth, poly(3-hydroxyoctanoate) (PHO) accumulation and its properties. Flask-scale experiments identified octanoic acid as an effective precursor for PHO biosynthesis, whereas excessive substrate loadings negatively affected culture performance. Continuous feeding of carbon and nitrogen sources in a fed-batch bioreactor increased biomass concentration to approximately 20 g/L while maintaining a PHO content of about 50% w/w of dry cell weight. Phosphorus limitation did not improve PHO accumulation and instead reduced biomass formation. Continuous magnesium feeding increased biomass concentration to approximately 26 g/L while maintaining intracellular PHO content. The produced PHO exhibited condition-dependent differences in selected molecular weight characteristics, while its thermal transition temperatures showed only small absolute variations. Overall, the proposed nutrient feeding strategies can provide a robust basis for improving process productivity while maintaining consistent biopolymer quality. Full article

(This article belongs to the Special Issue Innovative Bioreactor Design and Advanced Optimization Strategies for Biorefineries and Bioprocessing)

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16 pages, 5968 KB

Open AccessArticle

Hydrochemical Characteristics of the Suzhou Mining Area and Their Correlation with Drainage Water from Coalbed Methane Wells

by Mingyang Du, Caifang Wu, Xiaoqi Wang and Yu Wang

Processes 2026, 14(17), 2851; https://doi.org/10.3390/pr14172851 (registering DOI) - 5 Sep 2026

Abstract

The Suzhou mining area contains abundant coalbed methane resources. Analyzing the hydrochemical characteristics of formation and drainage water from coalbed methane wells is of considerable importance for the efficient extraction of coalbed methane. Using hydrochemical test data from formation water, produced water, and [...] Read more.

The Suzhou mining area contains abundant coalbed methane resources. Analyzing the hydrochemical characteristics of formation and drainage water from coalbed methane wells is of considerable importance for the efficient extraction of coalbed methane. Using hydrochemical test data from formation water, produced water, and the main coal seam of four coalbed methane wells, this study systematically investigated the relationship between hydrogeochemical characteristics and drainage water from coalbed methane wells. The results indicate that the trace elements in the main coal seam were similar to those in the water samples from the coal-bearing Permian sandstone aquifer (CPSA), both of which showed elevated levels of Ba. The water samples from the fourth aquifer of the Cenozoic Era (Q4 aquifer) primarily underwent ion exchange between Na⁺ and K⁺ in the water and Ca²⁺ and Mg²⁺ in the formation minerals. The water samples from coalbed methane wells, CPSA, Carboniferous Taiyuan Formation limestone aquifer (CTFLA), and Ordovician limestone aquifer (OLA) primarily underwent ion exchange between Ca²⁺ and Mg²⁺ in the water and Na⁺ and K⁺ in the formation minerals. Full article

(This article belongs to the Special Issue Exploration, Exploitation and Utilization of Coal and Gas Resources, 3rd Edition)

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27 pages, 10293 KB

Open AccessFeature PaperArticle

Natural Deep Eutectic Solvents as Innovative Multifunctional Ingredients in Cosmetic Formulations: Scaling up from Lab to Industry

by Justyna Werner, Ewa Kilian-Pięta, Kornelia Rzepczyk, Mateusz Szczygiełda, Agnieszka Duczmal, Daria Mysiak and Damian Krystian Kaczmarek

Processes 2026, 14(17), 2850; https://doi.org/10.3390/pr14172850 - 4 Sep 2026

Abstract

In recent years, the cosmetic and dermo-cosmetic industries have experienced a shift driven by the principles of green chemistry and the growing consumer demand for clean-beauty platforms. Conventional personal care formulations heavily rely on synthetic glycols, petroleum-derived penetration enhancers, and heavy chemical preservatives [...] Read more.

In recent years, the cosmetic and dermo-cosmetic industries have experienced a shift driven by the principles of green chemistry and the growing consumer demand for clean-beauty platforms. Conventional personal care formulations heavily rely on synthetic glycols, petroleum-derived penetration enhancers, and heavy chemical preservatives to stabilize active ingredients and optimize topical application. However, these ingredients are increasingly scrutinized due to their associated carbon footprints and processing inefficiencies. Consequently, the development of multi-functional, bio-based, and ecologically sustainable solvents has emerged as a primary frontier in modern cosmetic engineering. For the first time, this study focused on determining the physicochemical properties and direct cosmetic application potential of Natural Deep Eutectic Solvents (NADESs) based on 1,3-propanediol (PDO) and glycerin (GLY) paired with organic acids (citric, succinic, malic, and lactic) at a 6:1 molar ratio. Unlike traditional, highly viscous eutectic mixtures, the engineered NADESs successfully optimized liquid dynamic viscosities, overcoming a major barrier for topical application. The new NADESs and, for comparison, a physical mixture of their substrates were incorporated into aqueous serums and O/W emulsions. Accelerated stability trials (40 °C/4 °C, 3 months) combined with pH monitoring revealed that while liquid serums maintained exceptional stability, the emulsion formulations were highly dependent on the specific acid structures. All formulations of cosmetics demonstrated very good radical scavenging activity (up to 89% DPPH inhibition) and microbiological purity, complying with the ISO 17516:2014 standard. Furthermore, in vivo sensory evaluations visualized via heatmaps confirmed that NADESs effectively eliminated the characteristic “sticky effect” of polyols, significantly enhancing product ease of application on skin. This study provides the first systematic evidence that these NADESs offer seamless cold-process compounding, reduced homogenization times, and simplified single-pot operations. Consequently, this work establishes a novel, clean-beauty-compliant platform for advanced dermo-cosmetic manufacturing. Full article

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

23 pages, 743 KB

Open AccessArticle

Comparative Removal of Pharmaceutically Active Compounds Using Membrane Filtration Processes

by Ramy M. Al-Alawy, Mudhar A. Al-Obaidi, Alhassan H. Ismail and Iqbal M. Mujtaba

Processes 2026, 14(17), 2849; https://doi.org/10.3390/pr14172849 - 4 Sep 2026

Abstract

For the purpose of removing pharmaceutically active chemicals (PhACs) from wastewater, this study experimentally assesses the removal efficiency of four membrane filtration technologies: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) using four model pharmaceuticals, including nicotine (NCT), diclofenac sodium (DCF), [...] Read more.

For the purpose of removing pharmaceutically active chemicals (PhACs) from wastewater, this study experimentally assesses the removal efficiency of four membrane filtration technologies: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) using four model pharmaceuticals, including nicotine (NCT), diclofenac sodium (DCF), 4-acetamidoantipyrine (4AAA), and ranitidine hydrochloride (RNT), spiked in a controlled synthetic wastewater matrix under identical operating conditions. Furthermore, this study investigates how steric and electrostatic interactions, along with membrane physicochemical characteristics would control the separation behavior. The influence of operating pressure is also evaluated to signify its role in controlling removal efficacy. The experimental results demonstrate limited removal efficiency for MF and UF membranes (rejection below 20% and 30%, respectively, across the tested operating pressures), particularly for low-molecular-weight PhACs, which is attributed to their relatively large transport pathways that permit dissolved solutes to penetrate with minimal retention. In contrast, NF and RO membranes achieved significantly higher rejection rates of more than 75% and more than 95%, respectively (one-way ANOVA, p < 0.05), for the tested PhACs. Generally, these results have ascertained the dominance of size, electrostatic, and charge mechanisms for NF and the effective removal of PhACs with RO due to strong solute transport inhibition through the dense barrier. Furthermore, an insignificant effect of operating pressure on the performance of MF and UF is noticed if compared to a stronger influence on NF and RO, where increased pressure initially enhances removal rate but may ultimately plateau as rejection mechanisms stabilize under polarization and fouling impacts. Full article

(This article belongs to the Section Separation Processes)

29 pages, 29216 KB

Open AccessArticle

Numerical Simulation Analysis of the Impact of Forest Wildfire on Buried Pipelines

by Xiran Cheng, Jiang Meng, Panfeng Hu, Xue Min, Hang Yang and Qian Huang

Processes 2026, 14(17), 2848; https://doi.org/10.3390/pr14172848 - 4 Sep 2026

Abstract

In recent years, forest fires have occurred frequently, and extremely high temperatures can easily cause plastic deformation of buried pipelines. To clarify the temperature-stress variation law of natural gas pipelines under wildfire action, this study, based on heat transfer theory and using the [...] Read more.

In recent years, forest fires have occurred frequently, and extremely high temperatures can easily cause plastic deformation of buried pipelines. To clarify the temperature-stress variation law of natural gas pipelines under wildfire action, this study, based on heat transfer theory and using the finite element method, constructs a numerical model of a buried pipeline and analyzes the thermo-mechanical sequential coupling behavior of the pipe–soil system. It elucidates the influence patterns of key factors such as burial depth, outer diameter, internal fluid pressure, soil thermal conductivity, and fire duration on the temperature-stress fields of the pipe and surrounding soil and investigates pipeline deformation under fire. The results show that burial depth is the most sensitive factor: when it increases from 0.2 m to 0.8 m, the maximum pipe temperature decreases from 291.4 °C to 32.4 °C, and the maximum von Mises stress decreases from 507 MPa to 236 MPa. Furthermore, increasing pipe outer diameter and soil thermal conductivity both exacerbate pipe temperature rise and stress accumulation. Meanwhile, the longer the duration, the more pronounced the soil heat storage lag. Additionally, when internal pressure increases from 2 MPa to 8 MPa, the pipe’s maximum stress increases by up to 10.8%. The analysis results can provide a theoretical basis for identifying high-risk pipeline sections and guiding route selection and protective measure optimization for pipelines crossing forested areas. Full article

(This article belongs to the Section Materials Processes)

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20 pages, 1280 KB

Open AccessFeature PaperArticle

Data-Driven Optimization of Coagulant Dosing and Cost Control in a Full-Scale Drinking Water Treatment Plant: A Case Study in Xiangtan, China

by Yizhou Long, Haiquan Fang, Baolin Hou, Guocheng Zhu and Andrew S. Hursthouse

Processes 2026, 14(17), 2847; https://doi.org/10.3390/pr14172847 - 4 Sep 2026

Abstract

Water treatment plants are essential urban infrastructure with direct implications for public health and everyday life. Data-driven management has received growing attention in drinking water treatment, particularly for optimizing chemical dosing to improve operational efficiency, reduce costs, and ease operator workload. AI-based prediction [...] Read more.

Water treatment plants are essential urban infrastructure with direct implications for public health and everyday life. Data-driven management has received growing attention in drinking water treatment, particularly for optimizing chemical dosing to improve operational efficiency, reduce costs, and ease operator workload. AI-based prediction of coagulant dosage has therefore become an active research topic. Existing studies, however, have focused mainly on model architecture, with less attention to data validity and cost control. In practice, many plants face data-quality problems, including inconsistent dosing records under similar water-quality conditions. Conventional data cleaning may also remove large portions of the dataset, which can weaken model reliability. This study proposes an artificial intelligence (AI) modeling framework for coagulation dosing that handles anomalous data, emphasizes data quality assurance, and combines cost-oriented feedforward prediction with feedback control. A genetic algorithm-optimized backpropagation (GA-BP) neural network was first evaluated on controlled laboratory data and full-scale plant data using the same core model architecture, allowing the effects of model configuration to be separated from those of data quality. Historical plant records were subsequently cleaned through expert-guided validation, approximate time-delay alignment, and turbidity-based classification of operating conditions. Settled-water turbidity was then used as a feedback signal to dynamically adjust subsequent coagulant dosage and assess the resulting chemical savings. Changes in the input structure produced only modest improvements in full-scale prediction performance (R² = 0.53–0.72). In contrast, data cleaning and process-based data organization markedly improved predictive performance, with R² values increasing to 0.927–0.969. Standalone AI models achieved only moderate dosage reductions, while their integration with real-time turbidity feedback provided the best cost-control performance. The model-based control strategy reduced average coagulant consumption by 10.37%, with a maximum reduction of 21.33% at a settled-water turbidity target of 1.9 nephelometric turbidity units (NTU). Across the evaluated feedback-control scenarios, manual dosing was up to 32.83% higher than the corresponding feedback-controlled dosage. Overall, AI models can fit coagulation-dosing data and predict coagulant dosage with sufficient accuracy, but data quality assurance remains the main factor determining model performance. Effective cost control also requires real-time turbidity-based feedback regulation rather than model outputs alone. Full article

(This article belongs to the Section Environmental and Green Processes)

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22 pages, 1734 KB

Open AccessArticle

Assessing the Sustainability Transition of Mexico’s Electricity System: Life-Cycle Impacts, Energy Indices, and Resource Use

by Diana Karen Zavala-Vega, Edgar Geovanni Mora-Jacobo, Carlos Antonio Padilla-Esquivel, César Ramírez-Márquez and José María Ponce-Ortega

Processes 2026, 14(17), 2846; https://doi.org/10.3390/pr14172846 - 4 Sep 2026

Abstract

The global energy transition is driving power systems toward lower-carbon electricity generation, requiring sustainability assessments that consider environmental burdens beyond direct carbon emissions. This study evaluates Mexico’s electricity system using life cycle assessment, resource analysis, and energy sustainability indices. The main novelty of [...] Read more.

The global energy transition is driving power systems toward lower-carbon electricity generation, requiring sustainability assessments that consider environmental burdens beyond direct carbon emissions. This study evaluates Mexico’s electricity system using life cycle assessment, resource analysis, and energy sustainability indices. The main novelty of this study is the development of four energy sustainability indices derived from EI99H damage results: the Index of Environmental Change per Energy Unit, Relative Environmental Change Index, Per Capita Environmental Impact, and Environmental Intensity Metric. These indices capture temporal environmental change, generation-related variation, population-related burden, and environmental impact per unit of electricity. Results show improvements in fuel oil, water, and biomass performance between 2013 and 2023, whereas natural gas and coal impacts increased. Mexico exhibits a lower per capita environmental burden than Germany and Spain, while France shows the lowest value, largely due to its nuclear-based electricity mix. Human Health damage is 55% higher than Ecosystem Quality, mainly due to fossil fuel combustion. Hydroelectric generation shows substantial water demand, while solar and wind have negligible requirements. Rising natural gas costs constrain competitiveness, whereas renewables maintain low operating costs. Full article

(This article belongs to the Section Energy Systems)

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35 pages, 3527 KB

Open AccessArticle

A Data–Physics Dual-Driven Intelligent Diagnostic Method for Downhole Drilling Risks

by Kun Shao, Lizhi Xiao, Yue Liu, Huihui Wang, Zhengzhi Zhou, Zhanjun Jia and Qichen Sun

Processes 2026, 14(17), 2845; https://doi.org/10.3390/pr14172845 - 4 Sep 2026

Abstract

Safe drilling in hydrate-bearing sediments is essential for environmentally responsible natural gas hydrate development. Complex pressure variations, fluid migration, and mechanical disturbances during drilling may increase the risks of gas influx, lost circulation, pipe sticking, and wellbore instability. To improve diagnostic robustness under [...] Read more.

Safe drilling in hydrate-bearing sediments is essential for environmentally responsible natural gas hydrate development. Complex pressure variations, fluid migration, and mechanical disturbances during drilling may increase the risks of gas influx, lost circulation, pipe sticking, and wellbore instability. To improve diagnostic robustness under heterogeneous and noisy drilling conditions while reducing dependence on large-scale manually labeled datasets, this study develops an adaptively coupled data–physics dual-driven diagnostic framework based on a self-organizing map (SOM) and a competitive classifier. Unlike a conventional one-way SOM–classifier cascade, changes in the downstream classification loss are fed back to adjust the SOM neighborhood radius, thereby coupling unsupervised feature mapping with supervised risk classification. In addition, class-conditional pressure-window and torque–drag consistency penalties are linked to the predicted class probabilities so that physical information directly participates in the optimization of applicable fluid-related and pipe-sticking risk predictions. Risk categories without an explicitly available physical residual remain primarily data-driven. Experiments on a hybrid measured–simulated dataset show that the proposed model achieves a test-set accuracy of 97.67%, outperforming representative baseline models. When 20% Gaussian noise is added, the accuracy decreases by only 4.20 percentage points. A three-layer data acquisition–edge-computing–cloud-monitoring early-warning system is implemented through MATLAB/VC integration. In a pilot field trial, a representative well-kick risk was identified 12 min earlier than by a conventional threshold-based alarm, and the missed-alarm rate decreased from 15% to 3%. The proposed method provides an engineering-oriented framework for improving drilling safety and environmental risk control during natural gas hydrate development. Full article

(This article belongs to the Special Issue Environmentally Friendly Production of Energy from Natural Gas Hydrates, 2nd Edition)

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15 pages, 1307 KB

Open AccessArticle

The Volatile Profile and Seasonal Shifts of Greek-Grown Yuzu (Citrus junos) Peels and Leaves

by Georgia Xenikaki, Evgenia Panou, Vasileios Ziogas and Ioanna Chinou

Processes 2026, 14(17), 2844; https://doi.org/10.3390/pr14172844 - 4 Sep 2026

Abstract

This study presents the first characterization of peel and leaf essential oils (EOs) from Citrus junos Sieb. ex Tanaka (yuzu) cultivated in Greece, evaluating seasonal maturation effects on their chemical profiles. EOs were extracted through hydrodistillation from samples harvested between September and November [...] Read more.

This study presents the first characterization of peel and leaf essential oils (EOs) from Citrus junos Sieb. ex Tanaka (yuzu) cultivated in Greece, evaluating seasonal maturation effects on their chemical profiles. EOs were extracted through hydrodistillation from samples harvested between September and November (stages H1–H3) and analyzed via GC-MS, identifying 32 and 38 volatile compounds in peel and leaf EOs, respectively. High yields were recorded for both peels (1.00–1.27%, peaking in H2) and leaves (0.28–0.39%, peaking in H1), exceeding values reported for East Asian and Mediterranean cultivars extracted through conventional methods (0.09–0.27% for peels; 0.04% for leaves). Peel EO matched the traditional yuzu chemotype, dominated by limonene (62.62–67.32%) and γ-terpinene (10.95–14.24%), but lacked β-phellandrene and contained higher amounts of thymol and sesquiterpenes. Early-stage peels (H1) were characterized by linoleic acid (2.26%), which cleared in subsequent months, indicating a marker for fruit immaturity. In contrast, leaf EO displayed a distinct profile dominated by β-phellandrene (27.92–29.60%), γ-terpinene (20.43–24.06%) and p-cymenene (8.95–10.86%) alongside 2,5-dimethoxy-p-cymene (2.92–3.54%). Late-stage harvests (H2 and H3) showed a more than three-fold increase in linalool (1.35% to 4.82%), enriching the oxygenated fraction and aroma quality. These results confirm that Mediterranean-grown yuzu maintains its aromatic identity while developing a high-yield regional profile, providing practical guidance for optimizing harvest timing across flavor, fragrance, and cosmetic applications. Full article

(This article belongs to the Special Issue From Plant to Product: Process-Centric Advances in Essential Oils—Extraction, Modeling, Standardization, and Use)

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16 pages, 11742 KB

Open AccessArticle

The Role of Photoelectric and Dense-Medium Cyclone Separation as a Precursor to Flotation in the Beneficiation of a Phosphate Ore

by Zhili Li, Dongsheng He, Wei Xu, Zongyu Zheng, Hua Liu, Yun Tang, Hongsheng Shao, Lianjun Shi, Yuan Tang, Yanhong Fu and Wanqing Li

Processes 2026, 14(17), 2843; https://doi.org/10.3390/pr14172843 - 4 Sep 2026

Abstract

To satisfy the industrial standards for phosphate products, phosphate ore must undergo beneficiation for the removal of gangue minerals such as carbonate minerals, silicate minerals, and clay minerals. Reverse flotation is commonly used to remove carbonate minerals from apatite. However, reverse flotation removes [...] Read more.

To satisfy the industrial standards for phosphate products, phosphate ore must undergo beneficiation for the removal of gangue minerals such as carbonate minerals, silicate minerals, and clay minerals. Reverse flotation is commonly used to remove carbonate minerals from apatite. However, reverse flotation removes carbonate gangue minerals but fails to eliminate silicate and clay minerals. The use of pre-concentration (such as dense-medium cyclones and photoelectric sorting) in phosphate ore beneficiation enables the early rejection of gangue before the ore enters the fine-grinding and complex flotation circuits, thereby providing a range of technical and economic benefits. In addition, pre-concentration holds the potential to reject silicate and clay minerals in the beneficiation of phosphate ore. The phosphate ore investigated in this study was obtained from Hubei, China. It is characterized by well-defined gangue banding, which facilitates the liberation of some gangue minerals at relatively coarse comminution sizes (−15 + 0.5 mm). Based on these characteristics, photoelectric separation and dense-medium cyclone separation were employed as pre-concentration methods prior to reverse flotation, with the aim of achieving economically viable recoveries and marketable product grades. The results indicate that the combined dense-medium cyclone separation–reverse flotation process was the most effective for this phosphate ore, producing a final concentrate with a P₂O₅ grade of 31.08% and a recovery of 81.91%. Comparative evaluation reveals notable differences in gangue removal efficiency among the tested processes. While both reverse flotation and the combined photoelectric separation–reverse flotation process effectively removed dolomite, the dense-medium cyclone separation–reverse flotation process demonstrated superior overall performance by enabling the simultaneous removal of both silicate and dolomite impurities. Full article

(This article belongs to the Section Separation Processes)

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20 pages, 850 KB

Open AccessArticle

Influence of Cultivar and Press-Extraction Temperature on Antioxidants, Quality and Stability of Avocado (Persea americana Mill.) Oil

by Liliana Llaure-Huingo, Fabio Citti, Elza Aguirre, Lorenzo Estivi, Arianna Cervi, Gilbert Rodriguez, Jasmin Zotelo-Villanueva, Andrea Brandolini and Alyssa Hidalgo

Processes 2026, 14(17), 2842; https://doi.org/10.3390/pr14172842 - 4 Sep 2026

Abstract

Avocado fruits unsuitable for consumption are often used to produce oil, prized by food and cosmetic industries. This research assessed how press-extraction temperatures (20 °C and 80 °C) and cultivars affected avocado oil color, antioxidants, fatty acids composition, physico-chemical parameters, saponification value, nutritional [...] Read more.

Avocado fruits unsuitable for consumption are often used to produce oil, prized by food and cosmetic industries. This research assessed how press-extraction temperatures (20 °C and 80 °C) and cultivars affected avocado oil color, antioxidants, fatty acids composition, physico-chemical parameters, saponification value, nutritional and health-related indices and stability. Fruits and oils from cultivars Fuerte, Gween, Hass, Topa Topa, and Zutano were evaluated, and significant differences (p ≤ 0.05) among varieties as well as between extraction temperatures were detected for most traits. Fresh avocado pulp contained 13.6–15.7 g/100 g lipids; the extraction yield was 36.5% at 20 °C and 49.8% at 80 °C. In general, 20 °C better preserved chlorophyll (61.5 mg/kg) than 80 °C (43.8 mg/kg). The carotenoid β-cryptoxanthin was lower in the samples extracted at 80 °C. Gween oil had the highest tocopherol content (on average, 229.8 mg/kg); β-tocopherol (susceptible to extraction temperature) was the most abundant (49.10%), followed by α-tocopherol (38.15%) and γ-tocopherol (12.75%). The oils extracted at 80 °C showed higher density, viscosity and acidity but inferior refractive index, peroxide and iodine than those extracted at 20 °C. The oxidative stability index at 110 °C, measured by Rancimat, decreased in oils extracted at 80 °C compared to those extracted at 20 °C (9.1 vs. 10.4 h). Pressure-extracted avocado oil maintained excellent qualitative and technological properties at both extraction temperatures, thus suggesting its suitability for several food uses, including salad dressing and, thanks to its thermal stability, cooking. Full article

(This article belongs to the Special Issue Chemical Insights into Food Antioxidants)

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15 pages, 6415 KB

Open AccessArticle

Corrosion Behavior of 304 Stainless Steel in Mixed Amine Absorbents

by Shuifei Li, Pengfei Zhu, Yongping Liu, Lang Wang, Jun Li, Qinglin Niu, Hao Chen and Yubin Zeng

Processes 2026, 14(17), 2841; https://doi.org/10.3390/pr14172841 - 4 Sep 2026

Abstract

Against the backdrop of global warming, carbon dioxide capture technologies are advancing rapidly. The chemical absorption method using organic amines as absorbents is one of the most widely used technologies in industry. Mixed organic amine absorbents show great promise for practical application; however, [...] Read more.

Against the backdrop of global warming, carbon dioxide capture technologies are advancing rapidly. The chemical absorption method using organic amines as absorbents is one of the most widely used technologies in industry. Mixed organic amine absorbents show great promise for practical application; however, few studies have investigated their corrosion behavior on 304 stainless steel. This paper studied the corrosion behavior of 304 stainless steel in mixed amine solutions through immersion coupon tests, electrochemical tests, and long-term corrosion tests. The results showed that in the mixed amine solution under CO₂ saturated load, the corrosion rate of 304 stainless steel increased from 0.0016 mm/a to 0.0065 mm/a (at 30 wt% amine concentration) as the temperature rose from 40 to 60 °C. With increasing amine concentration in the range of 15 to 30 wt%, the corrosion rate first increased and then decreased, reaching a maximum value of 0.0065 mm/a. As the chloride ion concentration increased from 0 to 200 mg/L, the corrosion rate increased from 0.0065 mm/a to 0.0099 mm/a, while the susceptibility to pitting corrosion remained extremely low. Calculated E_a, ΔH^‡, and ΔS^‡ values jointly demonstrated that the corrosion process under the experimental conditions was predominantly controlled by the interfacial electrochemical charge transfer reaction. After 72 h of immersion, the surface of 304 stainless steel remained in a stable passive state, resulting in very low corrosion rates under all tested conditions and no visible corrosion on the coupon surfaces. Long-term corrosion tests indicated that corrosion predominantly occurred during the initial immersion stage, and the material exhibited good self-passivation performance during long-term service. Full article

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

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24 pages, 2443 KB

Open AccessFeature PaperArticle

Rapid Fault Restoration Strategy of Power System Based on Mobile Operation and Maintenance Base

by Junjie Zhang, Ziping Peng, Gang Chen, Junting Liu and Na Cao

Processes 2026, 14(17), 2840; https://doi.org/10.3390/pr14172840 - 4 Sep 2026

Abstract

In recent years, power grids have grown increasingly complicated, and the rising penetration of new energy sources poses prominent risks to the secure and stable operation of power systems. As a critical technology for improving grid resilience and power supply reliability, mobile operation [...] Read more.

In recent years, power grids have grown increasingly complicated, and the rising penetration of new energy sources poses prominent risks to the secure and stable operation of power systems. As a critical technology for improving grid resilience and power supply reliability, mobile operation and maintenance bases are investigated in this paper, which proposes an optimal configuration method tailored to multi-scenario emergency power guarantee requirements of power systems. Monte Carlo sampling is adopted to simulate various fault scenarios, and a multi-index resilience evaluation system consisting of load loss rate, power shortage ratio and recovery indicators is established. On this basis, a pre-positioning optimization model is formulated to minimize the space–time scheduling cost of mobile operation and maintenance bases. To tackle the model complexity, nonlinear convergence factors and dynamic adaptive weight strategies are embedded into the conventional whale optimization algorithm, which improves the global search capability and convergence stability of the algorithm. Simulation results show that the proposed method outperforms the baseline case without mobile operation maintenance bases: system load curtailment drops from 1.27 MWh to 0.65 MWh, and the overall resilience index reaches 0.831, greatly boosting distribution network power recovery performance. In addition, the improved algorithm converges within 126 iterations. Compared with standard algorithms, it improves solving efficiency by 29.2% and cuts total scheduling cost by 15.8%, achieving a good trade-off between calculation precision and convergence speed. Full article

(This article belongs to the Special Issue Modeling, Optimization, and Control of Distributed Energy Systems, 2nd Edition)

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15 pages, 32262 KB

Open AccessArticle

Fabrication of Omega-3 Fatty Acid Oil-Loaded Microcapsule Powders Using Gum Arabic and β-Cyclodextrin

by Yeon-Joo Jeong, Jeong-Tae Kim, Si-Bin Lee, Hee-Chan Roh, Sang-Hyub Oh and Seong-Ho Choi

Processes 2026, 14(17), 2839; https://doi.org/10.3390/pr14172839 - 4 Sep 2026

Abstract

Microcapsule powders containing omega-3 fatty acid oils were prepared using gum arabic through an emulsion and spray-drying process and β-cyclodextrin through a filtration/drying process. The prepared powder samples were characterized by OM, SEM, TGA, DSC, and GC analysis. In the gum arabic formulation, [...] Read more.

Microcapsule powders containing omega-3 fatty acid oils were prepared using gum arabic through an emulsion and spray-drying process and β-cyclodextrin through a filtration/drying process. The prepared powder samples were characterized by OM, SEM, TGA, DSC, and GC analysis. In the gum arabic formulation, the EPA and DHA contents could not be determined after the spray-drying process by GC analysis. In the β-cyclodextrin formulation, GC analysis showed that the total EPA + DHA content changed from 661.41 mg/g in the original omega-3 fatty acid oil sample to 117.44 mg/g in the microcapsule powder sample. In the time-dependent peroxide value (PV) analysis, the oil recovered from the β-cyclodextrin powder showed a slightly higher mean PV than the process-matched original oil at Day 0, but lower mean PV values at Days 7 and 14. These results describe the preparation and characterization of omega-3 fatty acid oil-loaded microcapsule powder samples under the investigated conditions. Full article

(This article belongs to the Special Issue Advanced Processing and Integration of Functional Ingredients in Sustainable Food Systems)

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18 pages, 1630 KB

Open AccessArticle

Chickpea Aquafaba as a Functional Ingredient for Improving Coconut-Based Probiotic Beverage Stability

by Antonia Yvina Silva dos Santos, Fernanda Elaine Barros Souza, Sueli Rodrigues, Maria de Fátima Dantas Linhares and Thatyane Vidal Fonteles

Processes 2026, 14(17), 2838; https://doi.org/10.3390/pr14172838 - 4 Sep 2026

Abstract

Developing stable plant-based probiotic beverages requires innovative formulation strategies. While chickpea aquafaba, a protein-containing by-product, shows promise for the development of functional foods, its specific application in probiotic matrices remains underexplored. This study evaluated a coconut-based probiotic beverage supplemented with aquafaba by monitoring [...] Read more.

Developing stable plant-based probiotic beverages requires innovative formulation strategies. While chickpea aquafaba, a protein-containing by-product, shows promise for the development of functional foods, its specific application in probiotic matrices remains underexplored. This study evaluated a coconut-based probiotic beverage supplemented with aquafaba by monitoring viable cell counts, pH, sugar and organic acid profiles, and antioxidant activity during 30 days of refrigerated storage. A 2² full factorial experimental design was used to investigate the effects of aquafaba and sucrose concentrations on the viability of Lacticaseibacillus casei NRRL B-442. The selected formulation (30% aquafaba and 50 g/L sucrose) achieved the highest viable cell count after fermentation (9.88 ± 0.09 log CFU/mL), compared with 8.40 ± 0.07 log CFU/mL in the control (coconut). During 30 days of refrigerated storage, the formulation R4 maintained probiotic viability above the recommended functional threshold (>7.0 log CFU/mL), reaching 7.40 log CFU/mL at day 30, whereas the control (coconut) declined to 6.77 log CFU/mL. R4 formulation also exhibited a slower decline in pH (4.50 vs. 3.20 in the control (coconut) at day 30) and higher lactate concentration after fermentation (2.04 vs. 0.79 g/L). Carbohydrate profiling revealed sustained sucrose utilization during storage, while the control (coconut) showed early metabolic stabilization. Monte Carlo simulation estimated an 87.9% probability for R4 and 24.8% for the coconut control of meeting the predefined viability criterion of 7.0 log CFU/mL under the modeled storage conditions. R4 beverage maintained viable cell counts above the predefined criterion of 7.0 log CFU/mL throughout storage, unlike the control (coconut). These results emphasize that integrating formulation optimization with predictive microbiology and stochastic modeling is a key component for developing robust probiotic plant-based beverages. This approach provides a complementary framework for evaluating uncertainty in predicted probiotic viability under the evaluated storage conditions. Full article

(This article belongs to the Section Food Process Engineering)

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23 pages, 2638 KB

Open AccessArticle

Experimental Study on Temperature–Pressure Coupling Sensitivity and Burial Depth Response of Coal Permeability

by Yunxun Wei, Xuehai Fu, Aisong Wang, Zeqing Lei and Junqiang Kang

Processes 2026, 14(17), 2837; https://doi.org/10.3390/pr14172837 - 4 Sep 2026

Abstract

The coupled effect of in situ temperature and stress complicates the permeability evolution of coal reservoirs, which restricts the exploration and evaluation of deep coalbed methane (CBM). Two high-rank coal samples were collected from the Sihe (SH) and Zhaozhuang (ZZ) mining areas, and [...] Read more.

The coupled effect of in situ temperature and stress complicates the permeability evolution of coal reservoirs, which restricts the exploration and evaluation of deep coalbed methane (CBM). Two high-rank coal samples were collected from the Sihe (SH) and Zhaozhuang (ZZ) mining areas, and multi-gradient coupled temperature–stress seepage experiments (20–50 °C, 8–32 MPa) as well as supporting triaxial mechanical tests were carried out to investigate the temperature and stress sensitivity of coal permeability. Combined with coal mechanical deformation characteristics, the transition depth mechanism of permeability evolution with burial depth was revealed. Experimental results indicate that coal permeability follows a negative exponential decay trend with increasing effective stress, and the evolution process can be divided into three stages: rapid attenuation, slow decline and stabilization. Temperature rise can weaken the stress attenuation degree of coal permeability under continuous effective stress loading and effectively reduce the stress sensitivity of coal reservoirs. Under constant confining pressure, permeability decreases linearly with rising temperature; the temperature-induced damage effect is prominent at low effective stress, while the regulatory effect of temperature is greatly weakened when fractures are compacted under high effective stress. An exponential function between permeability and burial depth was established based on coupled temperature–stress experimental data, and the critical burial depth of permeability transition depth in the study area was determined to be 550–600 m. The abrupt change interval of elastic modulus against confining pressure is consistent with the burial depth of permeability transition depth, which acts as the key mechanical factor dominating the nonlinear transition of reservoir permeability. This study provides experimental and theoretical support for the development of deep CBM in the study area. The results represent non-adsorbing gas (nitrogen) permeability under the investigated temperature–stress window (20–50 °C, 8–32 MPa) and should not be extrapolated to methane-bearing CBM reservoirs without adsorption–swelling corrections. The transition depth of approximately 550–600 m is a laboratory-derived estimate rather than a field-verified reservoir threshold. Full article

(This article belongs to the Special Issue Exploration, Exploitation and Utilization of Coal and Gas Resources, 3rd Edition)

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17 pages, 3762 KB

Open AccessArticle

Conceptual Design and Characteristic Analysis of Thorium-Based Long-Life Reactor Core

by Haoming Chen, Ling Chen, Yongfa Zhang and Cong Zhang

Processes 2026, 14(17), 2836; https://doi.org/10.3390/pr14172836 - 3 Sep 2026

Abstract

The design of a long-life reactor must not only achieve high burnup and closed fuel cycle utilization but also account for system heat transfer efficiency and inherent safety characteristics, thereby enhancing the long-term operational reliability of the reactor. To address these requirements, this [...] Read more.

The design of a long-life reactor must not only achieve high burnup and closed fuel cycle utilization but also account for system heat transfer efficiency and inherent safety characteristics, thereby enhancing the long-term operational reliability of the reactor. To address these requirements, this paper proposes a long-life core design scheme based on spent-fuel plutonium-thorium nitride fuel and lead-bismuth eutectic coolant. This scheme exploits the excellent breeding and burnup performance of thorium-based fuel under a fast neutron spectrum and employs the neutronics calculation code DRAGON and the subchannel code COBRA-PB to carry out corresponding core physics analysis and safety characteristic assessment. The results show that the core can achieve a 25-year long refueling cycle, with mild reactivity swing over the entire lifetime and low control difficulty; the core radial power gradually shifts inward with increasing burnup, achieving power flattening and thereby mitigating safety risks caused by localized deep burnup; both the control assembly and shutdown assembly possess sufficient reactivity margins, with a single set of control mechanisms capable of achieving effective shutdown upon independent insertion; all key reactivity coefficients of the core are negative, demonstrating negative-feedback regulation capability and inherent safety characteristics. Calculations indicate that the cladding temperatures of both the average channel and the hottest channel remain within limits, leaving ample safety margins, ensuring long-term cladding mechanical integrity, and effectively preventing high-temperature nitride fuel from melting through the cladding, resulting in outstanding overall core safety performance. This core design scheme can provide a theoretical basis and design reference for the engineering application of long-life reactors. It should be noted that this study is an exploratory investigation at the conceptual design stage of the core. The analysis is conducted on the basis that the fuel supply remains stable, that steady-state calculation models are adopted, and that the performance data of key materials are taken from published literature. Accordingly, the conclusions drawn still require further support from experimental verification and detailed design. Nevertheless, the proposed core design can provide a theoretical basis and design reference for the engineering application of long-life reactors. Full article

(This article belongs to the Section Energy Systems)

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