Processes

36 pages, 21140 KB

Open AccessReview

Performance Evolution and Regulation of Bentonite-Based Drilling Fluids Under Representative Complex Conditions: A Review

by Yundong Zheng, Shuya Wu, Lei Pu, Guochuan Qin, Yunxiao Cai, Yuhao Xu and Peng Xu

Processes 2026, 14(18), 3007; https://doi.org/10.3390/pr14183007 (registering DOI) - 20 Sep 2026

Abstract

As a core functional component of water-based drilling fluids, bentonite plays a critical role in regulating rheology, suspension capacity, filtration performance, and wellbore stability through its hydration, dispersion, and structure-building behavior. With drilling extending into deep, ultra-deep, and complex formations, harsh conditions such [...] Read more.

As a core functional component of water-based drilling fluids, bentonite plays a critical role in regulating rheology, suspension capacity, filtration performance, and wellbore stability through its hydration, dispersion, and structure-building behavior. With drilling extending into deep, ultra-deep, and complex formations, harsh conditions such as high temperature, salt contamination, pH fluctuation, and variations in solids content can significantly alter bentonite behavior, resulting in rheological instability, weakened suspension capacity, increased fluid loss, and deterioration of filter-cake quality. However, existing studies have often focused on individual additives or specific operating conditions, while a systematic understanding of bentonite performance evolution and corresponding regulation strategies remains limited. This review summarizes the types, basic characteristics, and engineering functions of bentonite in water-based drilling fluids, and discusses the performance changes in bentonite-based systems under high-temperature conditions, salt contamination, pH variation, and changes in bentonite solids content. On this basis, the main regulation approaches are categorized into fluid-chemistry regulation, functional-additive regulation, and solid-phase composition regulation, with emphasis on their effects on rheological behavior, suspension stability, fluid-loss control, and filter-cake quality. Relevant performance evaluation and characterization methods are also summarized. This review provides a systematic framework for understanding and regulating bentonite-based drilling-fluid performance under complex operating conditions and offers guidance for formulation design and engineering optimization. Full article

(This article belongs to the Special Issue Whole Petroleum System Theory and Multi-Scale Modeling of Hydrocarbon Generation, Migration and Enrichment)

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21 pages, 2172 KB

Open AccessArticle

Mitigating Defrosting in a Hybrid Air Conditioner Using a Ground Heat Exchanger Placed Downstream from an Outdoor Unit: Numerical Simulation and a Preliminary Experimental Demonstration

by Shumpei Funatani, Toshiya Yokose, Yusaku Tsukamoto and Koji Toriyama

Processes 2026, 14(18), 3006; https://doi.org/10.3390/pr14183006 (registering DOI) - 20 Sep 2026

Abstract

Air-source heat pumps suffer from the formation of frost on their outdoor coils while operating under cold and humid conditions, and the resulting periodic defrost cycles interrupt the heat supply and degrade both thermal comfort and efficiency. This study extends the hybrid air [...] Read more.

Air-source heat pumps suffer from the formation of frost on their outdoor coils while operating under cold and humid conditions, and the resulting periodic defrost cycles interrupt the heat supply and degrade both thermal comfort and efficiency. This study extends the hybrid air conditioner previously proposed by the authors, in which a ground heat exchanger is placed downstream of the outdoor heat exchanger, employing a shallow-buried water tank as a supplementary ground heat source to mitigate defrosting. A quasi-steady R32 vapor-compression cycle model was developed, coupled with lumped-capacitance thermal models of the room, the water tank, and the ground, including a frosting/defrosting model. Considering 2.2 kW heating at an outdoor temperature of +3.5 °C (with a relative humidity of 80%), the simulation predicted that the cumulative defrost time over 6 h would be reduced from 35 min (five events) to 0, the time required to reach the 20 °C set point would be shortened from 120 to 72 min, and the integrated coefficient of performance (COP) over 6 h would improve from 5.4 to 7.1. A preliminary one-hour winter heating experiment on a minimally modified commercial unit—one run per operating mode—showed that no defrosting occurred during hybrid operation, despite a higher outdoor relative humidity (74% vs. 46%), whereas two defrost events (inferred from the indoor outlet air velocity) totaling 12% of the run occurred in conventional operation, and the average COP increased from 1.8 to 3.0. An additional simulation with the as-built parameters of the prototype (300 L tank, tank-side conductance of about 60 W/K) reproduced this qualitative pattern under the hybrid-run weather, although with a small, nonzero predicted frost accumulation that remained below the defrost threshold. Because the two runs were conducted under different ambient conditions and the model was not calibrated against the tested system, the experiment provides qualitative rather than quantitative support for the simulated behavior; nevertheless, the simulation and the experiment consistently indicated the same relative advantage of the hybrid system, namely, the absence of defrosting and a higher COP. Future work will address repeated and extended experiments under matched conditions, model calibration, the optimization of the tank’s geometry and capacity, and the necessity of water agitation inside the tank. Full article

(This article belongs to the Special Issue Energy Storage Systems and Thermal Management (2nd Edition))

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25 pages, 10153 KB

Open AccessArticle

Long-Term Conductivity Evolution of Propped Fractures in Interbedded Highly Plastic Shale Reservoirs: Effects of Lithology and Proppant Parameters

by Junjie Liu, Wenjun Xu, Zhenwei Bai, Shun Qiu and Feng Jiang

Processes 2026, 14(18), 3005; https://doi.org/10.3390/pr14183005 (registering DOI) - 20 Sep 2026

Abstract

Interbedded shale reservoirs commonly contain multiple lithologies, such as shale and limestone, resulting in heterogeneous long-term fracture conductivity under identical proppant conditions. This lithological heterogeneity introduces uncertainty into proppant design and may lead to uneven stimulation effectiveness. This study investigates the effects of [...] Read more.

Interbedded shale reservoirs commonly contain multiple lithologies, such as shale and limestone, resulting in heterogeneous long-term fracture conductivity under identical proppant conditions. This lithological heterogeneity introduces uncertainty into proppant design and may lead to uneven stimulation effectiveness. This study investigates the effects of lithology, proppant size, and proppant areal concentration on the evolution of propped fracture conductivity and develops lithology-dependent empirical correlations to quantitatively describe long-term conductivity evolution within the tested parameter ranges. Conductivity experiments were performed using shale and limestone rock plates under simulated reservoir conditions of 80 °C and 40 MPa closure stress, with a long-term loading duration of 50 h. The results indicate that propped fracture conductivity exhibits strong stress sensitivity and time-dependent degradation. Continuous compaction of the proppant pack and reduction in effective flow channels are considered possible mechanisms contributing to conductivity loss during long-term loading. Under identical proppant parameters, limestone fractures generally exhibit higher long-term conductivity, while the difference in conductivity retention depends on proppant conditions rather than shale fractures, with the lithological difference becoming more pronounced under low-proppant-concentration and small-proppant-size conditions. Within the directly comparable conditions of 5 and 7.5 kg/m², increasing proppant size and areal concentration generally reduced the conductivity difference observed between shale and limestone fractures. For shale fractures, the experiments covering 5, 7.5, and 10 kg/m² further showed that the effect of areal concentration depended on proppant size. Based on the experimental data, lithology-dependent empirical correlations were established for shale and limestone fractures and evaluated using leave-one-condition-out cross-validation. The correlations provide a quantitative description of conductivity evolution within the tested parameter ranges. This study identifies lithology-dependent conductivity responses within the investigated proppant conditions and provides experimental evidence for adapting proppant design to heterogeneous interbedded shale reservoirs. Full article

(This article belongs to the Special Issue Process Engineering Innovations for a Transitioning Energy Landscape: From Fossil Fuels to a Low-Carbon Future)

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19 pages, 2319 KB

Open AccessArticle

Nonlinear Wave Modeling of Internally Heat-Integrated Air Separation Columns via Local Mechanism-Based Optimization

by Lin Cong and Hang Zhou

Processes 2026, 14(18), 3004; https://doi.org/10.3390/pr14183004 (registering DOI) - 20 Sep 2026

Abstract

Compared with conventional air separation columns, the internally heat-integrated air separation column (HIASC) offers superior energy efficiency. However, its structural complexity poses significant challenges for model-based online optimization and control. This study proposes a nonlinear wave model based on a model updating strategy, [...] Read more.

Compared with conventional air separation columns, the internally heat-integrated air separation column (HIASC) offers superior energy efficiency. However, its structural complexity poses significant challenges for model-based online optimization and control. This study proposes a nonlinear wave model based on a model updating strategy, which substantially reduces modeling complexity. First, wave propagation theory is employed to characterize the concentration distribution profiles and their propagation velocities within the HIASC. Subsequently, a localized analytical method based on the distributed wave velocity is developed from local mechanistic insights to evaluate waveform distortion. Furthermore, a model updating strategy is introduced, which determines the optimal updating frequency according to the degree of waveform deformation, thereby mitigating computational redundancy caused by excessive updates. Finally, the proposed strategy is integrated into the nonlinear wave model to achieve an optimal balance between accuracy and computational efficiency. Simulation results validate the effectiveness and robustness of the proposed modeling approach. Full article

(This article belongs to the Section Separation Processes)

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18 pages, 2134 KB

Open AccessArticle

Two-Stage Environmental Response of Sporosarcina pasteurii: Stepwise Alkaline–Low-NaCl Exposure and Subsequent Temperature Challenge

by Jianxin Wang, Haotian Zhang, Zhuo Li and Yusheng Li

Processes 2026, 14(18), 3003; https://doi.org/10.3390/pr14183003 (registering DOI) - 20 Sep 2026

Abstract

Microbially induced calcium carbonate precipitation (MICP) is influenced by the physiological response of ureolytic bacteria to local environmental backgrounds. This liquid-culture process-screening study examined responses of Sporosarcina pasteurii ATCC 11859 under combined alkaline–low-NaCl backgrounds and elevated temperatures relevant to inland aeolian-sand environments. Cultures [...] Read more.

Microbially induced calcium carbonate precipitation (MICP) is influenced by the physiological response of ureolytic bacteria to local environmental backgrounds. This liquid-culture process-screening study examined responses of Sporosarcina pasteurii ATCC 11859 under combined alkaline–low-NaCl backgrounds and elevated temperatures relevant to inland aeolian-sand environments. Cultures were sequentially exposed to five pH-NaCl backgrounds at 30 °C, followed by temperature treatments (35–41 °C) under three selected backgrounds. Cell density (OD₆₀₀), urease activity, and apparent dry precipitate mass (ADPM), used as an operational dry-residue endpoint, were measured. Temperature, pH–NaCl background, and their interaction significantly affected urease activity and OD₆₀₀, whereas ADPM showed a significant temperature effect but was not interpreted as quantitative CaCO₃ production. A composite analysis indicated that pH 9.3, 1.4‰ NaCl and 35–37 °C represented a coordinated liquid-culture response range. At pH 9.3, 1.4‰ NaCl, and 37 °C, urease activity, OD₆₀₀, and ADPM were 1.155 mM urea min⁻¹, 1.662, and 1.14 g, respectively. Overall, the identified range provides a practical liquid-culture basis for subsequent sand-tray stabilization tests under aeolian-sand conditions. Full article

(This article belongs to the Special Issue Advances in Bioprocess Technology, 2nd Edition)

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20 pages, 5012 KB

Open AccessArticle

Bridging the Gap Between MP-PIC CPFD Hydrodynamic Simulations and CREC-GS-Optiprobes Data in a Sand Fluidized Bed for Biomass Gasification

by Marcos Navarro Salazar, Nicolas Torres Brauer and Hugo de Lasa

Processes 2026, 14(18), 3002; https://doi.org/10.3390/pr14183002 (registering DOI) - 20 Sep 2026

Abstract

This study examines a sand bubbling fluidized bed containing cylindrical biomass pellets. It demonstrates the advantages of integrating fiber-optic measurements—such as those obtained with CREC-GS-Optiprobes—with CPFD Barracuda VR^® 25.0.1 computational modeling. Experimental data collected by using CREC fiber-optic probes in a 43.8 [...] Read more.

This study examines a sand bubbling fluidized bed containing cylindrical biomass pellets. It demonstrates the advantages of integrating fiber-optic measurements—such as those obtained with CREC-GS-Optiprobes—with CPFD Barracuda VR^® 25.0.1 computational modeling. Experimental data collected by using CREC fiber-optic probes in a 43.8 cm diameter, laboratory-scale cold gasifier unit are used to validate the radial phase distributions predicted by CPFD Barracuda VR^® simulations for the gas, emulsion, and biomass pellet phases. In addition, it is shown that the bubble rise velocity measurements provided by the CREC probes offer complementary insights into the limitations of CPFD Barracuda VR^® simulations. These measurements highlight the importance of bubble–bubble interactions, including the “push” exerted by neighboring bubbles on a target bubble. Based on this approach, a combined experimental–computational methodology is proposed, leading to the development of a bubble rise velocity equation. This equation is expressed as a function of the isolated bubble’s axial chord and as a function of the superficial gas velocity in excess present at minimum fluidization conditions. It is anticipated that this equation will be beneficial for the design and optimization of sand fluidized bed gasifiers operating with biomass pellets, particularly by improving the prediction and capture of bubble dynamics. Full article

(This article belongs to the Special Issue Multiphase and Continuous Flow Reactor Technologies for Biomass Conversion)

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25 pages, 1908 KB

Open AccessArticle

Novel Approaches to Spontaneous and Controlled Fermentation of Romanian Small Autumn Watermelon (Citrullus lanatus)

by Silviu Măntăilă, Oana-Viorela Nistor, Corina Neagu, Nicoleta Balan, Ioana-Otilia Ghinea and Doina-Georgeta Andronoiu

Processes 2026, 14(18), 3001; https://doi.org/10.3390/pr14183001 (registering DOI) - 20 Sep 2026

Abstract

Romanian small autumn watermelon (Citrullus lanatus), late-harvested at the end of October, is a valuable vegetal source of natural carbohydrates, carotenoids, vitamins (especially A and C), fibers, and minerals, and, above all, it provides hydration while being low in calories. To [...] Read more.

Romanian small autumn watermelon (Citrullus lanatus), late-harvested at the end of October, is a valuable vegetal source of natural carbohydrates, carotenoids, vitamins (especially A and C), fibers, and minerals, and, above all, it provides hydration while being low in calories. To extend the period during which Romanian small autumn watermelon can be consumed and its associated health benefits, the present study aims to preserve these fruits through spontaneous and controlled fermentation. The conditions were identical in both fermentation routes: a room temperature of 21 ± 1 °C for 4 days, followed by 17–18 °C in the dark thereafter. Several physical, chemical, and microbiological investigations were conducted at 7-day intervals over the 63 days of storage. The study revealed several advantages of controlled fermentation: a rapid decrease in pH, a uniform lactic acid concentration, an improved phytochemical profile, and better preservation of color and texture. Controlled fermentation of vegetables offers greater predictability, safety, and consistency than spontaneous fermentation, making it suitable for industrial application. Full article

(This article belongs to the Special Issue Applications of Non-Thermal and Thermal Technologies in Food Processing, 2nd Edition)

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27 pages, 23727 KB

Open AccessArticle

Multiscale Surface Characterization of LPBF-Fabricated 17-4 PH Stainless Steel TPMS and Flat Plates After Aging, Shot Blasting, and Hydrophobic Coating

by Fatema Tuz Zohra, Hribhu Chowdhury and Bahram Asiabanpour

Processes 2026, 14(18), 3000; https://doi.org/10.3390/pr14183000 (registering DOI) - 20 Sep 2026

Abstract

Multiscale surface characterization is essential for understanding the surface condition of laser powder bed fusion (LPBF)-fabricated metallic structures and regions subjected to different post-processing conditions. This study examines LPBF-fabricated 17-4 PH stainless steel (SS) triply periodic minimal surface (TPMS) prototypes to characterize geometry-dependent [...] Read more.

Multiscale surface characterization is essential for understanding the surface condition of laser powder bed fusion (LPBF)-fabricated metallic structures and regions subjected to different post-processing conditions. This study examines LPBF-fabricated 17-4 PH stainless steel (SS) triply periodic minimal surface (TPMS) prototypes to characterize geometry-dependent manufacturing features and representative flat plate regions associated with aging, shot blasting, hydrophobic coating, and combined blasting-coating conditions. Hirox digital microscopy was used to examine macro- to microscale surface features on the TPMS prototypes and flat plates, while Hirox 3D profiling was used to evaluate the roughness response of the flat plate treatment regions. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) provided higher-resolution surface morphology and elemental composition from selected flat plate regions. Hirox imaging revealed anisotropic surface textures aligned with LPBF scan paths, pore presence, and staircase-like features on curved TPMS surfaces. Three-dimensional profiling identified different geometric mean Rz values among the examined flat plate regions; the blasted-plus-coated regions on the untreated baseline plate, U-BC, and the aged plate, A-BC, had the smallest reported values within their respective plate sets. SEM observations identified LPBF-related features, including balling, pores, particle adhesion, localized surface irregularities, and coating cracks. Localized EDS analysis showed Fe-, Cr-, Ni-, Cu-, and Si-containing elemental profiles in the examined U-0 and A-0 regions, whereas the analyzed U-C region exhibited strong Si and O signals, coating-associated elemental features, and reduced substrate contribution. These results demonstrate the importance of combining surface morphology, profile roughness, coating condition, and localized elemental composition to document geometry-dependent TPMS features and regional surface condition differences across the examined flat plates. Full article

(This article belongs to the Special Issue Advanced Materials and Performance Characterization in Additive Manufacturing)

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17 pages, 4156 KB

Open AccessArticle

Research on the Effectiveness of Gas Control in Low-Permeability Coal Seams Based on Microbial Gas Dissolution

by Qingsong Li, Wei Zhang, Xianwei Heng, Shujin Zhang, Zhengpeng Duan, Dan Feng and Zhenhua Shen

Processes 2026, 14(18), 2999; https://doi.org/10.3390/pr14182999 (registering DOI) - 20 Sep 2026

Abstract

To shorten the gas control period in low-permeability coal seams, the effectiveness of microbial gas dissolution technology for gas control was investigated through a combination of field tests and numerical simulations. First, three groups of injection boreholes were constructed, and the microbial gas-dissolving [...] Read more.

To shorten the gas control period in low-permeability coal seams, the effectiveness of microbial gas dissolution technology for gas control was investigated through a combination of field tests and numerical simulations. First, three groups of injection boreholes were constructed, and the microbial gas-dissolving solution was injected into the coal seam, followed by an evaluation of the treatment effect after three days. Furthermore, based on a multiphysics-coupled modeling framework, the conventional borehole drainage process was simulated using the Partial Differential Equation (PDE) module of COMSOL Multiphysics to compare the evolution of coal seam gas pressure under conventional drainage with the field performance of the gas dissolution treatment. The results showed that the injected bioactive solution promoted methane oxidation and rapidly reduced the gas content and pressure in the treated region. After 3 days of gas dissolution treatment, the average gas content and gas pressure within the overlapping influence zones between the injection borehole groups decreased by 38.0% and 80.7%, respectively, relative to their initial values. However, the treatment effect gradually weakened with increasing distance from the injection zone, indicating spatial attenuation of the effective influence of the bioactive solution in the low-permeability coal seam. Comparatively, conventional drainage required approximately 68 days to reduce the gas pressure to the same level achieved by the gas dissolution treatment within 3 days, demonstrating that gas dissolution technology can drastically accelerate the gas control cycle. Nevertheless, further large-scale application requires consideration of economic feasibility and continued optimization of injection parameters and field implementation procedures. Full article

(This article belongs to the Special Issue Experimental and Numerical Simulation of Coal Mining)

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34 pages, 1356 KB

Open AccessArticle

FCC-Bench and Adaptive Multi-Scale Inference for Multivariate Forecasting Using Data from a Continuous FCC Unit

by Ye Tang, Nan Jiang, Hansheng Suo, Linghui Li, Zun Gu, Runping Qin and Haowei Hu

Processes 2026, 14(18), 2998; https://doi.org/10.3390/pr14182998 (registering DOI) - 20 Sep 2026

Abstract

Fluid catalytic cracking (FCC) units are central to modern oil refining. FCC operation is complex, with strong nonlinearity and high-dimensional spatiotemporal coupling, making process monitoring, soft sensing, and operational optimization difficult. Multivariate forecasting supports these tasks. Public datasets and forecasting benchmarks provide limited [...] Read more.

Fluid catalytic cracking (FCC) units are central to modern oil refining. FCC operation is complex, with strong nonlinearity and high-dimensional spatiotemporal coupling, making process monitoring, soft sensing, and operational optimization difficult. Multivariate forecasting supports these tasks. Public datasets and forecasting benchmarks provide limited data for one continuous FCC process, and forecasters transferred to FCC operation often need retraining to maintain accuracy as operation changes. To address these issues, we construct the Fluid Catalytic Cracking Benchmark (FCC-Bench) and propose Adaptive Multi-Scale Inference (AMSI). FCC-Bench focuses on one continuous FCC process, with 129 variables over 62.5 days, capturing operating changes and supporting traceable saved-array metric calculation. AMSI runs a frozen forecaster at three context lengths and fuses forecasts with adaptive per-variable weights, so short contexts respond quickly to sudden changes while long contexts reduce noise during slow changes. In the FCC-Bench last-20% rolling comparison, AMSI reaches the lowest mean MSE and MAE among the evaluated methods of 1.2909 and 0.8101. The same settings still give the lowest error on another period from the same unit and on another unit. Full article

(This article belongs to the Special Issue Application of Artificial Intelligence in Oil and Gas Engineering)

11 pages, 2962 KB

Open AccessArticle

Relationship Between Pore-Throat and Pressure in Oil Charging in Tight Conglomerate Reservoirs of the Xiazijie Formation in Manan Area, Junggar Basin: Proved from NMR Experiment

by Xincai You, Lei Zhang, Hailong Chen, Rui Yuan, Zhiwen Zou, Fangpeng Dou and Na Xiao

Processes 2026, 14(18), 2997; https://doi.org/10.3390/pr14182997 (registering DOI) - 20 Sep 2026

Abstract

The Xiazijie Formation in the Manan Area, Junggar Basin, is an extra-low- to ultra-low-porosity and -permeability deep conglomerate reservoir. The relationship between pore-throat and pressure in oil charging in this tight reservoir is undefined at the initial exploration stage. By combining high-pressure Hg [...] Read more.

The Xiazijie Formation in the Manan Area, Junggar Basin, is an extra-low- to ultra-low-porosity and -permeability deep conglomerate reservoir. The relationship between pore-throat and pressure in oil charging in this tight reservoir is undefined at the initial exploration stage. By combining high-pressure Hg injection with one-dimensional nuclear magnetic resonance (NMR) experiments, a conversion relationship between relaxation time in NMR and pore-throat radius during high-pressure Hg injection was established. Online NMR displacement experiments were conducted at pressures of 2, 5, 15, 25, 35, and 45 MPa. The variation patterns of reservoir oil saturation and the lower limit of the oil-charged pore-throat radius were investigated. The results show that the oil saturation of conglomerate reservoirs ranges from 8% to 32% at a charging pressure of 2 MPa, and from 19% to 52% at a pressure of 45 MPa. The average oil saturation follows a monotonically increasing power function with charging pressure. Oil saturation rapidly increases as charging pressure increases at low pressures, while it gradually increases at high pressures. The lower limit of the oil-charged pore-throat radius ranges from 12 to 82 nm at a charging pressure of 2 MPa, and from 8 to 20 nm at 45 MPa. This lower limit follows a monotonically decreasing power function with charging pressure. The lower limit of the oil-charged pore-throat radius rapidly decreases as charging pressure increases at low values, whereas it gradually decreases with a further increase in charging pressure. Understanding the relationship between oil saturation and the oil-charged pore-throat radius lower limit at different charging pressures could improve the understanding of the reservoir-forming rules and liquid-injection development in the tight conglomerate reservoir of the Xiazijie Formation in the Manan Area. Full article

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

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21 pages, 3431 KB

Open AccessArticle

Rhamnolipid-Based Nanosized Dispersed Formulation for Enhanced Fracturing-Fluid Flowback: Phase Behavior, Interfacial Properties, and Porous-Media Performance

by Juan Wu, Junwei Fu, Qixiang Mei, Lu Lai and Ping Mei

Processes 2026, 14(18), 2996; https://doi.org/10.3390/pr14182996 (registering DOI) - 20 Sep 2026

Abstract

Fracturing-fluid retention caused by capillary trapping and surfactant loss during transport through porous media can impair post-fracturing productivity in tight reservoirs. In this study, a rhamnolipid/isopropanol/limonene/water nanosized dispersed formulation was developed as a biosurfactant-based flowback aid. Pseudo-ternary phase diagrams, dynamic light scattering, surface- [...] Read more.

Fracturing-fluid retention caused by capillary trapping and surfactant loss during transport through porous media can impair post-fracturing productivity in tight reservoirs. In this study, a rhamnolipid/isopropanol/limonene/water nanosized dispersed formulation was developed as a biosurfactant-based flowback aid. Pseudo-ternary phase diagrams, dynamic light scattering, surface- and interfacial-tension measurements, contact-angle measurements, porous-medium transport experiments, and sand-packed drainage tests were employed to evaluate the formulation behavior and flowback-aiding performance. The largest optically clear single-phase region was obtained at a rhamnolipid/isopropanol mass ratio of 3:1. The formulation maintained nanoscale hydrodynamic dimensions at NaCl or CaCl₂ concentrations up to 10 g/L, while systems containing ≤80 wt.% water exhibited comparatively stable hydrodynamic sizes during 7 d of aging at 70 °C. The equilibrium surface tension reached 25.87 mN/m at 200 mg/L. After passage through the proppant/rock-powder-packed medium, the formulation retained a surface tension of 32.02 mN/m and produced a water contact angle of 95°, compared with 51.20 mN/m and 67°, respectively, for the rhamnolipid aqueous solution. The maximum relative aiding-drainage enhancement approached 89.2% at 2000 mg/L. These results indicate an association among formulation characteristics, interfacial properties, porous-medium transport behavior, and drainage performance, and support the potential of the rhamnolipid-based dispersed formulation as a flowback-aid candidate under the investigated laboratory conditions. Full article

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

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34 pages, 6013 KB

Open AccessArticle

RAPO-RL-TAC: Risk-Aware Partial-Order Reinforcement Learning with Timed Automata Completion for the Interval Job Shop Problem

by Pujie Han, Yiheng Liu and Min Huang

Processes 2026, 14(18), 2995; https://doi.org/10.3390/pr14182995 (registering DOI) - 20 Sep 2026

Abstract

In the Interval Job Shop Problem (IJSP), operation processing times are represented by intervals, making machine-sequencing decisions sensitive to temporal uncertainty. We propose Risk-Aware Partial-Order Reinforcement Learning with Timed Automata Completion (RAPO-RL-TAC), which couples Risk-Aware Partial-Order Reinforcement Learning (RAPO-RL) for machine-order construction with [...] Read more.

In the Interval Job Shop Problem (IJSP), operation processing times are represented by intervals, making machine-sequencing decisions sensitive to temporal uncertainty. We propose Risk-Aware Partial-Order Reinforcement Learning with Timed Automata Completion (RAPO-RL-TAC), which couples Risk-Aware Partial-Order Reinforcement Learning (RAPO-RL) for machine-order construction with Timed Automata Completion (TAC) for execution-time resolution of deferred sequencing decisions. Risk awareness focuses on preserving temporal flexibility in machine-order relations whose preferred ordering is sensitive to interval uncertainty. RAPO-RL selectively commits comparatively determinate machine conflicts while retaining a bounded set of timing-sensitive relations. TAC completes unresolved relations as execution evolves, while statistical model checking characterises completion-time variability across timed executions. On 14 ORB and LA benchmark instances, RAPO-RL-TAC achieves mean midpoint makespans 2.92% and 1.63% lower than population-based neighbourhood search (PNS) and genetic algorithm (GA), respectively. Compared with reproduced Fast Elitist Artificial Bee Colony (fEABC) variants, RAPO-RL-TAC achieves a lower midpoint than at least one variant on 7 of 14 instances. In the controlled ablation study, RAPO-RL-TAC achieves a 13.85% lower mean midpoint makespan than hard enforcement of the learned relations. These results indicate that risk-aware selective commitment preserves temporal flexibility while maintaining competitive nominal schedule quality under interval uncertainty. Full article

(This article belongs to the Special Issue Simulation, Modeling, and Decision-Making Processes in Manufacturing Systems and Industrial Engineering, 2nd Edition)

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26 pages, 3654 KB

Open AccessArticle

Collaborative Optimization of Ladle Furnace Operating Parameters Using Prediction Models and Case-Guided Genetic–Tabu Search

by Yuhong Du, Xiaolong Li and Dongfeng He

Processes 2026, 14(18), 2994; https://doi.org/10.3390/pr14182994 (registering DOI) - 19 Sep 2026

Abstract

Intelligent control of the ladle furnace (LF) process and its endpoint is essential for product quality and stable continuous casting. Existing studies mainly address endpoint prediction or operating-parameter recommendation. Prediction models rarely provide multivariable operating schemes directly, whereas recommendation models often suffer from [...] Read more.

Intelligent control of the ladle furnace (LF) process and its endpoint is essential for product quality and stable continuous casting. Existing studies mainly address endpoint prediction or operating-parameter recommendation. Prediction models rarely provide multivariable operating schemes directly, whereas recommendation models often suffer from insufficient coordination among modules and complex commissioning. This study proposes a collaborative LF operating-parameter optimization method combining endpoint prediction with case-guided genetic–tabu search. Given the initial heat state and target endpoint temperature, the method treats electric energy input, power-on duration, and key material additions as decision variables, evaluates each candidate using temperature and composition prediction models, and coordinates the variables through a unified objective. A dynamic weighting mechanism coupling generational annealing with feasible-population temperature-error feedback balances endpoint quality against resource input. Case-based reasoning guides population initialization, while a real-coded genetic algorithm and tabu search strengthen global exploration and local exploitation. For 400 independent historical heats, the method obtained a recommendation satisfying all model constraints for every heat. Relative to the corresponding historical operations, the mean recommended quantities of lime, slag agent, aluminum granules, high-carbon ferromanganese, electric energy input, and power-on duration were reduced by 6.98%, 12.79%, 9.34%, 8.85%, 7.89%, and 8.95%, respectively. Case-guided initialization improved first-generation solution quality and early convergence, whereas tabu search enhanced mid-to-late local refinement. The method converts existing endpoint-prediction capability into coordinated multivariable operating recommendations. Full article

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

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33 pages, 11029 KB

Open AccessArticle

Development and Characterization of Blended Açaí-Sunflower Oil Emulsions Stabilized with Modified Starch and Maltodextrin for Incorporation into Yogurte

by Nayla P. B. G. Souki, Matheus A. Chaves and Samantha C. Pinho

Processes 2026, 14(18), 2993; https://doi.org/10.3390/pr14182993 (registering DOI) - 19 Sep 2026

Abstract

Açaí oil (AO) is extracted from the pulp of the açaí fruit (Euterpe oleracea Mart.), a species native to the Brazilian Amazon region. The oil is recognized for its bioactive compounds and antioxidant properties, making it promising for functional foods. In this [...] Read more.

Açaí oil (AO) is extracted from the pulp of the açaí fruit (Euterpe oleracea Mart.), a species native to the Brazilian Amazon region. The oil is recognized for its bioactive compounds and antioxidant properties, making it promising for functional foods. In this study, a commercial lipid blend containing 40% açaí oil and 60% sunflower oil (SO) was emulsified using modified dextrin (Capsul^®), maltodextrin, and xanthan gum. The selected formulation, containing 8% of the oil blend, exhibited satisfactory physical stability over 30 days of refrigerated storage, with a mean droplet diameter of 7.3 µm on day 1, remaining within 7–8 µm throughout storage. The peroxide value increased from 2.09 to 3.95 mEq/L emulsion, whereas TBARS decreased from 1.86 to 1.51 mmol MDA/L emulsion. DPPH and ABTS apparent antioxidant activities remained relatively stable over the storage time. Yogurts containing 8%, 10%, and 12% of the oil-blend emulsion and 5% inulin were evaluated for physicochemical, antioxidant, rheological, microbiological, and sensory acceptance. Emulsion incorporation modified yogurt structure and rheological behavior while maintaining microbiological safety. Sensory acceptance scores ranged from approximately 6.0 to 7.4 on the nine-point hedonic scale. Overall, the emulsions effectively incorporated the blended oil into yogurt, providing desirable technological, antioxidant, and sensory properties. Full article

(This article belongs to the Special Issue Advances in Interactions of Polymers in Emulsion Systems)

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18 pages, 1201 KB

Open AccessArticle

Analysis of Interlayer Stress Transfer Mechanism of Bimetallic Composite Pipes

by Hong Pan, Yang Ren, Yang Wang, Jianwei Lin, Qiongyu Zhou, Huirong Huang, Xueyuan Long, Qian Huang, Yuan Tian, Yanhui Ren and Jie Zhong

Processes 2026, 14(18), 2992; https://doi.org/10.3390/pr14182992 (registering DOI) - 19 Sep 2026

Abstract

Addressing the ill-defined interlayer stress transfer mechanisms and the risk of stress exceeding material limits in bimetallic composite pipes under landslide hazards in high-steep mountainous regions, this study establishes a refined pipe–soil interaction finite element (FE) framework. Built upon a previously validated coupled [...] Read more.

Addressing the ill-defined interlayer stress transfer mechanisms and the risk of stress exceeding material limits in bimetallic composite pipes under landslide hazards in high-steep mountainous regions, this study establishes a refined pipe–soil interaction finite element (FE) framework. Built upon a previously validated coupled model, interlayer interfacial contact formulations were enhanced, and valid operating regimes were systematically screened using the ultimate tensile strength (UTS) as the structural failure criterion. The regulatory impacts of soil displacement, internal operating pressure, and base pipe wall thickness on interlayer stress transfer efficiency were quantitatively mapped. The results demonstrate that within the valid service window, the interlayer stress transfer coefficient continuously escalates with soil displacement, identifying 3 m as the critical displacement threshold for base pipe yielding. Elevating internal pressure increases the stress transfer coefficient, which is mainly dominated by the high sensitivity of the thin liner’s membrane stress to internal pressure, and is secondarily promoted by the enhancement of interfacial shear capacity caused by increased contact pressure. Crucially, increasing the base pipe wall thickness from 12 mm to 15 mm effectively reduces the peak stress of the base pipe from 440.5 MPa to 310.2 MPa within the safe operational regime (1 m displacement) while systematically lowering the interlayer stress transfer coefficient η from 0.84 to 0.78 at the 3 m critical yielding threshold. This structural shielding effect is fundamentally driven by the enhanced structural stiffness (flexural rigidity) of the outer base pipe, which directly absorbs the primary geotechnical bending load and consequently lowers the deformation demand transmitted across the interface. Ultimately, this work unveils the core interlayer transfer mechanism characterized by “base-pipe stiffness dominance, interfacial shear transmission, elastic modulus mismatch governing stress allocation, and deformation compatibility steering load pathways,” providing a robust theoretical foundation for the interfacial integrity design of bimetallic composite pipelines in landslide-prone mountainous environments. Full article

(This article belongs to the Section Energy Systems)

56 pages, 9299 KB

Open AccessReview

Research Progress on Intelligent Color-Sorting Equipment for Post-Harvest Chili Peppers: Machine Vision, Pneumatic Actuation, and System Integration

by Junhao Cao, Yapeng Wu, Liming Zhang, Yu Zhang and Zhong Tang

Processes 2026, 14(18), 2991; https://doi.org/10.3390/pr14182991 (registering DOI) - 19 Sep 2026

Abstract

Post-harvest sorting is essential for converting the biological variability of chili peppers into consistent commercial grades, efficient processing, and higher market value. Rapid advances in machine vision, multimodal sensing, deep learning, and intelligent actuation are transforming sorting equipment from rule-based classifiers into integrated [...] Read more.

Post-harvest sorting is essential for converting the biological variability of chili peppers into consistent commercial grades, efficient processing, and higher market value. Rapid advances in machine vision, multimodal sensing, deep learning, and intelligent actuation are transforming sorting equipment from rule-based classifiers into integrated perception-to-execution systems. However, existing studies often evaluate isolated algorithms or components, leaving limited evidence that recognition accuracy translates into reliable sorting during continuous operation. We conducted a structured narrative review of English-language studies published from January 2008 to July 2026 using Web of Science, Scopus, AESC, and PubMed. Evidence was synthesized along a perception-to-execution chain, distinguishing pepper-specific sorting systems and component studies from cross-crop engineering evidence. Direct system-level evidence was concentrated in a small number of chili and bell pepper studies, whereas much of the technical discussion drew on apple, tomato, potato, sweet potato, and onion research. Visible, spectral, fluorescence, and multimodal features can distinguish ripeness, color grades, and surface defects, although performance remains sensitive to cultivar, illumination, pose, and dataset design. A small number of pepper sorting studies support the feasibility of integrating vision, conveying, and physical separation under specific operating conditions. Cross-crop studies inform the discussion of localization, pneumatic actuation, and system integration, but do not establish the performance of these approaches in chili pepper sorting. Reported performance is difficult to compare because studies rarely standardize latency, target association, false and missed rejections, product damage, energy use, and long-term reliability. Robust deployment therefore requires cross-batch datasets, synchronized target-level traceability, and evaluation protocols linking perception outputs to final physical destinations. This review identifies the boundaries of current pepper-specific evidence and proposes a system-level evaluation framework and research priorities for testing the transferability of cross-crop engineering approaches to pepper sorting. Full article

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

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14 pages, 7662 KB

Open AccessArticle

Toxic Efficacy of Nerium oleander Extracts as a Precise Strategy for Managing Pomacea canaliculata (Gastropoda) Eggs

by Qiulan Luo, Fei Zhou, Xinni Cai, Hui Zhu and Xiaoshan Cai

Processes 2026, 14(18), 2990; https://doi.org/10.3390/pr14182990 (registering DOI) - 19 Sep 2026

Abstract

The golden apple snail (Pomacea canaliculata) is a globally destructive invasive species. Existing control strategies primarily target adult snails, yet these approaches often fail due to the snails’ robust shells and lack of effective toxicity. To address this problem, extracts from [...] Read more.

The golden apple snail (Pomacea canaliculata) is a globally destructive invasive species. Existing control strategies primarily target adult snails, yet these approaches often fail due to the snails’ robust shells and lack of effective toxicity. To address this problem, extracts from Nerium oleander, Alocasia macrorrhiza, Euphorbia tirucalli and Aconitum carmichaelii were tested on the snail eggs. All four extracts exhibited toxicity at a 75% concentration, with N. oleander being the most potent. Specifically, this extract achieved a 95.42% mortality rate at 75% concentration and induced complete embryonic death at the 50% concentration. All four extracts induced significant oxidative stress-related physiological alterations in the eggs. Notably, N. oleander extract reduced the soluble protein content by 12% and altered key antioxidant enzyme activities (a 1.29-fold increase in SOD and CAT; a 48% decrease in ALT; a 3.52-fold and 5.67-fold increase in AST and POD, respectively). Field trials showed that fresh and dried N. oleander leaf extracts inhibited egg hatching by 96% and 93%, while embryonic observations confirmed developmental impairment. Further, to identify the bioactive components of N. oleander leaf extracts and lay a foundation for subsequent pesticide development, HPLC-MS analysis was performed, and 27 compounds belonging to 7 groups were identified. Collectively, N. oleander treatment induced oxidative stress-related physiological alterations and embryonic developmental impairment, which contributes to its ovicidal outcome. These findings lay a theoretical foundation for plant-derived ovicide development, inform eco-friendly pest management policies, and guide field control practices, highlighting N. oleander as a promising candidate for targeted P. canaliculata egg control. Full article

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

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45 pages, 1387 KB

Open AccessReview

Agro-Industrial Wastewaters as Feedstocks for Microbial Lipase Production: Integrating Enzyme Bioprocessing, Effluent Valorization and Wastewater Management

by Amina Laribi, Doria Naila Bouchedja and Bartłomiej Zieniuk

Processes 2026, 14(18), 2989; https://doi.org/10.3390/pr14182989 (registering DOI) - 19 Sep 2026

Abstract

Agro-industrial wastewaters contain substantial organic and lipid loads that pose environmental challenges but may also provide potentially low-cost substrates for microbial bioprocessing. This scoping review evaluated the use of agro-industrial wastewaters as fermentation feedstocks for microbial lipase production and their potential integration with [...] Read more.

Agro-industrial wastewaters contain substantial organic and lipid loads that pose environmental challenges but may also provide potentially low-cost substrates for microbial bioprocessing. This scoping review evaluated the use of agro-industrial wastewaters as fermentation feedstocks for microbial lipase production and their potential integration with wastewater treatment and resource recovery. Previous reviews have largely treated microbial lipase production, waste-derived fermentation substrates, and lipase-based wastewater treatment as separate topics. This review bridges these areas by focusing on liquid agro-industrial wastewaters as fermentation feedstocks and jointly evaluating lipase production, changes in wastewater quality, process conditions, analytical comparability, and technological readiness. Following PRISMA-ScR guidance, Scopus and the Web of Science were searched for studies published from 2016 to 2026, yielding 20 eligible articles. The evidence was heavily concentrated on olive mill wastewater and palm oil mill effluent, whereas other agro-industrial effluents were scarcely investigated. Yeasts, bacteria, filamentous fungi, mixed cultures, and recombinant whole-cell systems were employed, although cultivation strategies, wastewater conditioning, supplementation, and lipase assays varied substantially. Several studies combined lipase production with reductions in chemical oxygen demand, oil and grease, phenolic compounds, or other wastewater constituents. However, most processes remained at the shake-flask scale, while downstream recovery, detailed enzyme characterization, storage stability, catalyst reuse, and controlled scale-up were infrequently investigated. Wastewater-based lipase production therefore represents a promising circular-bioeconomy strategy, but further development requires standardized performance reporting, minimal-input cultivation, integrated final-effluent assessment, scale-up, and formal techno-economic and life-cycle assessment. Full article

(This article belongs to the Special Issue Applications of Microorganisms in Wastewater Treatment)

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