Processes

16 pages, 4425 KiB

Open AccessFeature PaperArticle

Effects of Fluidized Bed Coating with Carboxymethyl Cellulose and Pectin on the Physicochemical Properties of Fermented Black Bean Dregs

by Cheng Huang, Meng-I Kuo, Chun-Ping Lu, Bang-Yuan Chen, Chien-Cheng Yeh, Chia-I Chang, Cheng-Hsun Jao, Yi-Chung Lai and Jung-Feng Hsieh

Processes 2025, 13(4), 1066; https://doi.org/10.3390/pr13041066 (registering DOI) - 2 Apr 2025

Abstract

The changes in the physicochemical properties of fermented black bean dregs (FBBD) coated with carboxymethyl cellulose (CMC) solution (0–3%) and pectin solution (0–3%) on a fluidized bed were analyzed. The Carr index of the FBBD powder decreased from 55.4 ± 0.3% to 7.5 [...] Read more.

The changes in the physicochemical properties of fermented black bean dregs (FBBD) coated with carboxymethyl cellulose (CMC) solution (0–3%) and pectin solution (0–3%) on a fluidized bed were analyzed. The Carr index of the FBBD powder decreased from 55.4 ± 0.3% to 7.5 ± 0.4% after coating with CMC solution (3%) and to 11.3 ± 1.6% after coating with pectin solution (3%) for 120 min. After coating with CMC solution (3%) for 120 min, the proportion of medium-sized particles decreased significantly with the increased duration of the coating process, whereas the proportion of large-sized particles increased. Microstructural analysis by scanning electron microscopy showed that the particle size significantly increased and the surface changed from rough to smooth. The L* and b* values of the powder samples decreased from 45.5 ± 0.1 and 17.2 ± 0.1 to 32.9 ± 0.2 and 15.3 ± 0.1, respectively, whereas the a* value increased from 7.6 ± 0.1 to 8.9 ± 0.1; thus, the sample color changed from bright to dark and tended toward bluish and reddish colors. The wettability and solubility of the powder samples increased significantly with the increased duration of the coating process, but the water-holding capacity decreased. Moreover, FBBD coated with pectin solution (3%) and CMC solution (3%) on a fluidized bed for 120 min exhibited similar physicochemical properties. Thus, FBBD powder exhibited favorable flowability, wettability, and solubility after 120 min of coating with CMC solution (3%) or pectin solution (3%). Full article

(This article belongs to the Special Issue Development of Innovative Processes in Food Engineering)

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18 pages, 6145 KiB

Open AccessArticle

Classification and Analysis of Dominant Lithofacies of the Fengcheng Formation Shale Oil Reservoirs in the Mahu Sag, Junggar Basin, NW China

by An Xie, Heyuan Wu, Yong Tang, Wenjun He, Jingzhou Zhao, Weitao Wu, Jun Li, Yubin Bai and Liang Yue

Processes 2025, 13(4), 1065; https://doi.org/10.3390/pr13041065 (registering DOI) - 2 Apr 2025

Abstract

The exploration of the Fengcheng Formation has revealed the characteristic orderly coexistence of conventional reservoirs, tight reservoirs, and shale reservoirs, constituting a full spectrum of reservoir types, and is important for unconventional oil and gas exploration and development. Affected by frequent volcanic tectonic [...] Read more.

The exploration of the Fengcheng Formation has revealed the characteristic orderly coexistence of conventional reservoirs, tight reservoirs, and shale reservoirs, constituting a full spectrum of reservoir types, and is important for unconventional oil and gas exploration and development. Affected by frequent volcanic tectonic movement, hot and dry paleoclimate, and the close provenance supply distance, unique saline–alkaline lacustrine deposits formed during the depositional period of the Fengcheng Formation. The lithologies of the Fengcheng Formation are highly diverse, with endogenous rocks, volcanic rocks, terrigenous debris, and mixed rocks overlapping and forming vertical reservoir changes ranging from meters to centimeters. Owing to the complexity of rock types and scarcity of rock samples, the evaluation of reservoirs in mixed-rock has progressed slowly. Hence, we aimed to evaluate the characteristics of Fengcheng Formation shale oil reservoirs. Centimeter-level core characteristics were analyzed based on the lithological change and structural characteristics. To investigate the lithofacies of the Fengcheng Formation in the Mahu Sag and factors affecting reservoir development, high-frequency sedimentary structures were analyzed using sub-bio-buffering electron microscopy, energy spectrum testing, and fluorescence analysis. The results showed that the shale oil reservoirs in the study area can be divided into four categories: glutenite, volcanic rock, mixed rock, and endogenous rock. The reservoir capacity has improved and can be divided into eight subcategories. Mixed-rock reservoirs can be further divided into four subcategories based on differences in structure and composition. Differences in the bedding and dolomite content are the main factors controlling the differences in the physical properties of this type of reservoir. This study provides a reference for the classification and characteristic study of shale oil reservoirs in saline–alkali lake basins. Full article

(This article belongs to the Special Issue Theoretical Progress in the Exploration and Development of Deep Coal-Measure Gas)

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24 pages, 2685 KiB

Open AccessArticle

Characteristics of Pyrolysis Products of Tar-Rich Coal Under Cryogenic Pretreatment with Liquid Nitrogen

by Tao Xu, Lingyun Chen, Jie Chen, Yurui Lei, Xinxin Wang, Xinyu Yang and Zhifu Yang

Processes 2025, 13(4), 1064; https://doi.org/10.3390/pr13041064 (registering DOI) - 2 Apr 2025

Abstract

The conventional pyrolysis of tar-rich coals faces limitations in maximizing tar yield and optimizing tar composition, often resulting in inefficient resource utilization and elevated emissions of CO₂. This study investigates a novel cryogenic pretreatment method using liquid nitrogen to enhance pyrolysis [...] Read more.

The conventional pyrolysis of tar-rich coals faces limitations in maximizing tar yield and optimizing tar composition, often resulting in inefficient resource utilization and elevated emissions of CO₂. This study investigates a novel cryogenic pretreatment method using liquid nitrogen to enhance pyrolysis efficiency, aiming to improve tar yield and transform tar quality for sustainable coal utilization. Three tar-rich coals underwent cryogenic pretreatment at varying temperatures (0 to −90 °C) via liquid nitrogen, followed by pyrolysis. The product distribution (tar, gas) and quality were analyzed and compared to conventional pyrolysis and the Gray–King assay. The cryogenic pretreatment increased the tar yield by 25.8–44.6% compared to conventional methods, achieving a maximum yield of 7.8–16.0 wt% at −90 °C. The emissions of CO₂ decreased by 12.7–27.4%, while CH₄ and H₂ proportions rose by 15.1–60.2%, enhancing gas energy content. The pretreatment reduced benzene compounds by 4.4–13.9 wt% and increased aromatic derivatives by 13.9–20.5 wt%, indicating a shift toward higher-value chemicals. The cryogenic approach demonstrates the dual benefits of boosting tar productivity while reducing carbon emissions, offering a promising path for cleaner and more efficient coal pyrolysis. Full article

(This article belongs to the Special Issue Comprehensive Evaluation and Utilization of Coal Measure Mineral Resources)

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18 pages, 4469 KiB

Open AccessArticle

Optimized Extraction of Saponins from Camelia Oleifera Using Ultrasonic-Assisted Enzymes and Their Surface Performance Evaluation

by Na Zhang, Zaid Mohammed Sulaiman Ebrahim, Lei Tao, Wenyang Shi, Wenxin Li and Wenlong Lu

Processes 2025, 13(4), 1063; https://doi.org/10.3390/pr13041063 - 2 Apr 2025

Abstract

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results [...] Read more.

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results indicated that the maximum yield of tea saponin was 69.81 mg/g under the optimum conditions of an enzyme concentration of 0.67%, a solvent-to-material ratio of 16.82 mL/g, an extraction temperature of 58.14 °C and an extraction time of 1.89 h. The surface activity experimental study results indicated that the critical micelle concentration of tea saponin was 0.5 g/L at 30 °C, and the lowest surface tension was 39.61 mN/m. The surface tension and CMC of tea saponin remained basically unchanged between 30 °C to 60 °C. When the pH of the solution was slightly acidic, the surface tension of tea saponin decreased significantly, while the CMC remained almost unchanged. Tea saponin has good salt and hard water resistance, and its surface tension decreases to a certain extent in both saltwater and hard water. The foam volume of tea saponin can reach 490 mL, with a half-life of 2350 s, and the foam is relatively stable. The combination of tea saponin and other surfactants has a certain synergistic effect. The critical micelle concentration of its complex system with the natural surfactant rhamnolipids can increase by 69.23%, and the surface tension can be reduced to a minimum of 22.56 mN/m. Moreover, by using the proposed method, the foam performance and stability of the system have been improved to a certain extent. This has significant practical significance for fully utilizing and developing waste camellia dried cake resources. Full article

(This article belongs to the Section Chemical Processes and Systems)

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12 pages, 4596 KiB

Open AccessArticle

Numerical Simulation and Application of Coated Proppant Transport in Hydraulic Fracturing Systems

by Qiang Du, Hua Yang, Shipeng He, Pingxuan Deng, Xun Yang, Chen Lin, Zhiyun Sun, Lan Ren, Hanxiang Yin, Bencheng He and Ran Lin

Processes 2025, 13(4), 1062; https://doi.org/10.3390/pr13041062 - 2 Apr 2025

Abstract

The enhancement of proppant conductivity in shale gas fracturing can be effectively achieved through the implementation of coated proppants. After soaking, non-curable viscous resin-coated proppants exhibit progressive viscosity development and spontaneous agglomeration during the transportation phase. Furthermore, upon fracture closure, the formed proppant [...] Read more.

The enhancement of proppant conductivity in shale gas fracturing can be effectively achieved through the implementation of coated proppants. After soaking, non-curable viscous resin-coated proppants exhibit progressive viscosity development and spontaneous agglomeration during the transportation phase. Furthermore, upon fracture closure, the formed proppant agglomerates demonstrate significant stability and do not flow back with the fracturing fluid through the wellbore. While contemporary research has mostly focused on proppant coating methodologies, the transportation process of these proppants remains insufficiently investigated. To fill this knowledge gap, a sophisticated migration two-phase flow coupling model was developed utilizing the computational fluid dynamics–discrete element method (CFD-DEM) approach. This model incorporates the bond contact forces between film-coated proppant particles, accounting for their distinctive cementing characteristics during transport. Through comprehensive numerical simulations, the transport properties of film-coated proppants were systematically analyzed. Field application indicated that compared with conventional continuous sand fracturing, the amount of proppant after treatment with viscous resin film was reduced by 35% and the production was increased by about 25–30%. Additionally, the optimization of the field-scale coated proppant transport processes was achieved through the implementation of a lower fracturing displacement combined with staged sand addition. Full article

(This article belongs to the Section Chemical Processes and Systems)

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19 pages, 6348 KiB

Open AccessArticle

The Methane Adsorption Ability of Lacustrine Shale and Its Controlling Factors: A Case Study of Shale from the Jurassic Lianggaoshan Formation in the Sichuan Basin

by Pei Fu, Dazhi Zhang, Mingyi Hu, Gang Yang, Sile Wei and Fan Zeng

Processes 2025, 13(4), 1061; https://doi.org/10.3390/pr13041061 - 2 Apr 2025

Abstract

For lacustrine shale oil and gas reservoirs with coexisting hydrocarbon fluid properties, evaluating the adsorption capacity of shale is of significant importance for the exploration of lacustrine shale oil and gas. Taking the lacustrine shale from the Jurassic Lianggaoshan Formation in the northern [...] Read more.

For lacustrine shale oil and gas reservoirs with coexisting hydrocarbon fluid properties, evaluating the adsorption capacity of shale is of significant importance for the exploration of lacustrine shale oil and gas. Taking the lacustrine shale from the Jurassic Lianggaoshan Formation in the northern Sichuan Basin as an example, this study conducted pyrolysis, scanning electron microscopy (SEM), and high-pressure methane isotherm adsorption tests to investigate the methane adsorption capacity of lacustrine shale and its controlling factors. The research findings are as follows: (1) The organic matter content in the study area’s lacustrine shale is moderate, with organic types ranging from II to III, and it is within the oil generation window stage. The mineral composition exhibits characteristics of high clay and low silica content; (2) Both the TOC (total organic carbon) and clay minerals promote the methane adsorption capacity of lacustrine shale; however, due to the overall moderate–low TOC levels, the storage space is primarily composed of inorganic pores; (3) A high clay mineral content provides more surface area, becoming a primary factor influencing shale adsorption capacity. This indicates that semi-deep lake deposits also possess exploration potential. Full article

(This article belongs to the Section Energy Systems)

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15 pages, 2224 KiB

Open AccessArticle

Fe³⁺ and Mn²⁺ Removal from Water Solutions by Clinoptilolite Zeolites as a Potential Treatment for Groundwater Wells

by William D. Arenhardt, Felipe Ketzer, João H. C. Wancura, Janaina Seraglio, Fabio L. Carasek, Guilherme Zin, Jean F. F. Calisto, Clovis A. Rodrigues, Alessandra C. de Meneses, José Vladimir Oliveira and Jacir Dal Magro

Processes 2025, 13(4), 1060; https://doi.org/10.3390/pr13041060 - 2 Apr 2025

Abstract

This study presents data on the water quality of the Guarani Aquifer based on samples collected from distinct groundwater wells in the western region of Santa Catarina State, Brazil. Among the analyses performed, the results indicated the need for treatment to ensure suitability [...] Read more.

This study presents data on the water quality of the Guarani Aquifer based on samples collected from distinct groundwater wells in the western region of Santa Catarina State, Brazil. Among the analyses performed, the results indicated the need for treatment to ensure suitability for human consumption, particularly concerning Fe³⁺ and Mn²⁺ ions. Accordingly, natural (NCLIN) and activated clinoptilolite (ACLIN) zeolites were evaluated for ion removal from synthetic aqueous solutions through adsorption. NCLIN demonstrated excellent performance in adsorbing Fe³⁺ and Mn²⁺ ions, achieving removal efficiencies of over 98% and 95%, respectively, at a controlled pH of 6.0 (NCLIN) or 4.0 (ACLIN). A non-linear approach to modeling adsorption kinetics indicated that the pseudo-second-order model best represented the experimental data. This finding suggests that the interaction between the adsorbent and Fe³⁺ and Mn²⁺ ions occur through electron sharing and chemisorption. Equilibrium modeling analysis revealed that adsorption on NCLIN occurred in a monolayer, whereas adsorption on ACLIN followed a multilayer pattern. This behavior is attributed to the activation process with H₂SO₄, which led to dealumination and the formation of HSO₃⁻ groups on the adsorbent surface. Full article

(This article belongs to the Special Issue Advances in Wastewater and Solid Waste Treatment Processes)

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15 pages, 3579 KiB

Open AccessArticle

Mechanical, Morphological, and Electrical Characteristics of Cu-Loaded Acrylic Paint on a Fused Deposition Modeling Printed Polylactic Acid Surface

by Sudhir Kumar, Pulkit Tiwari and Seyed Saeid Rahimian Koloor

Processes 2025, 13(4), 1059; https://doi.org/10.3390/pr13041059 - 2 Apr 2025

Abstract

Fused deposition modeling (FDM) printing has become increasingly popular for exploring advanced material matrices with a polymeric base. This study uses a low-energy method to investigate the metallization process on a surface created by 3D printing. This involves using an acrylic-paint-based solution to [...] Read more.

Fused deposition modeling (FDM) printing has become increasingly popular for exploring advanced material matrices with a polymeric base. This study uses a low-energy method to investigate the metallization process on a surface created by 3D printing. This involves using an acrylic-paint-based solution to disperse the copper (Cu) powder on a polylactic acid (PLA) substrate, allowing for an evaluation of the fabricated samples’ mechanical, morphological, absorbance, and capacitance properties. The study findings indicate a gradual increase in tensile strength as the content of Cu in the acrylic paint layer on the PLA substrate increases. There was a clear and consistent increase in the tensile strength of the specimen, ranging from 13.5 MPa (sample 1) to 15.6 MPa (sample 5). Similarly, the percentage of strain at failure also showed a noticeable increase, ranging from 4.2% (sample 1) to 8.6% (sample 5). The scanning electron microscopy (SEM) investigation revealed the presence of completely enveloped Cu particles in acrylic paint on the FDM-printed surface of the PLA. The Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS) indicated a significant change in the absorbance pattern as the copper content in the layer increased. The augmented absorbance values serve as an advantage because they demonstrate enhanced UV light interaction, which correlates with the increase in capacitance measurements of 6 to 8 pF. This result suggests that the fabricated sample potentially leads to favorable alterations in material characteristics for applications that demand stable capacitance alongside improved mechanical properties. The SEM analysis supported the observed trends. Full article

(This article belongs to the Special Issue Development and Characterization of Advanced Polymer Nanocomposites)

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21 pages, 6227 KiB

Open AccessArticle

Study of the Optimization of Pressurization Timing and Parameters for Enhanced Well Production Based on an Integrated Wellbore-Gas Reservoir Coupling Dynamic Analysis Method for Shale Gas Wells

by Yusong Chen, Feng He, Yadong Yang, Qike Zheng, Junfu Zhang, Weiyi Luo, Haiji Ma, Zhenglan Li and Yu Peng

Processes 2025, 13(4), 1058; https://doi.org/10.3390/pr13041058 - 2 Apr 2025

Abstract

An integrated dynamic analysis and prediction method for shale gas reservoirs based on wellbore coupling has been developed, focusing on optimizing well production. This method integrates a three-dimensional geological model, a mechanical model, simulations of fracture propagation, and a numerical simulation in a [...] Read more.

An integrated dynamic analysis and prediction method for shale gas reservoirs based on wellbore coupling has been developed, focusing on optimizing well production. This method integrates a three-dimensional geological model, a mechanical model, simulations of fracture propagation, and a numerical simulation in a gas reservoir to establish a continuous-flow model that links the gas reservoir, fractures, and wellbore after hydraulic fracturing. It enables comprehensive integrated production dynamic analysis and predictions. The process begins by trajectory modeling and attribute assignment. Subsequently, based on the regional tectonic map, contour lines are drawn, regional tectonic surfaces are established, segmentation and clustering are performed, and appropriate fracturing fluids and proppants are selected to simulate fracture network expansion. Finally, the integrated dynamic simulation model of the gas reservoir and wellbore is constructed using the Petrel RE module, considering the combined effects of wellbore flow and reservoir seepage. The model was developed from a single well and through three-dimensional geological modeling, the simulation of fracture propagation in hydraulic fracturing, and a numerical simulation. An integrated dynamic licensing and prediction methodology was established for a shale gas integration model with wellbore-gas reservoir coupling. Additionally, this study analyzes and establishes the optimal pressurization timing and regime for the pressurizer to enhance gas well production. The model was successfully applied for historical matching and dynamic predictions in a block in the southern Sichuan region, producing results closely aligned with the actual data, thus providing a robust tool for predicting the future production profiles of shale gas wells. Full article

(This article belongs to the Section Energy Systems)

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19 pages, 4506 KiB

Open AccessArticle

A Novel Triethylammonium Tetrafluoroborate Electrolyte for Enhanced Supercapacitor Performance over a Wide Temperature Range

by Ezgi Yurttas, Yavuz Gokce, Nazife Isik Semerci, Emine Yagmur and Zeki Aktas

Processes 2025, 13(4), 1057; https://doi.org/10.3390/pr13041057 - 2 Apr 2025

Abstract

The wide operating temperature and voltage window are favourable properties that increase the practical applications of supercapacitors. Ionic liquids (IL) are suitable electrolytes that allow supercapacitors to be used in wide operating ranges. In this study, triethylammonium tetrafluoroborate (Et₃NHBF₄) [...] Read more.

The wide operating temperature and voltage window are favourable properties that increase the practical applications of supercapacitors. Ionic liquids (IL) are suitable electrolytes that allow supercapacitors to be used in wide operating ranges. In this study, triethylammonium tetrafluoroborate (Et₃NHBF₄) is tested as a new IL to operate supercapacitors in a wide temperature range (−40 °C, 25 °C, and 80 °C) in the presence of commercial activated carbon. The performance of Et₃NHBF₄ is compared to two different commercial ILs. This study also investigates the application of heat treatment to determine suitable activated carbon surface characteristics for ILs. The results indicate that heat treatment enhances the electrode–electrolyte interaction, and the electrochemical performances of the supercapacitors prepared from the heat-treated activated carbon are significantly higher than the original commercial activated carbon. Electrochemical tests show that the synthesised Et₃NHBF₄ (with propylene carbonate) can be used over a wide temperature range and has a better energy storage performance, especially at −40 °C (specific capacitance of 42.12 F/g at 2 A/g), compared to the other two commercial ionic liquids. Full article

(This article belongs to the Special Issue Recent Advances in Conductor Materials for Energy Storage and Electrocaloric Applications)

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15 pages, 1957 KiB

Open AccessArticle

Machine Learning-Based Sizing Model for Tapered Electrical Submersible Pumps Under Multiple Operating Conditions

by Jinsong Yao, Guoqing Han, Xingyuan Liang and Mengyu Wang

Processes 2025, 13(4), 1056; https://doi.org/10.3390/pr13041056 - 1 Apr 2025

Abstract

Dewatering gas wells typically exhibit a high gas–liquid ratio, making tapered electrical submersible pump (ESP) systems a common choice. However, the flow rate within the pump varies significantly along its length, and production parameters fluctuate considerably across different stages of operation for a [...] Read more.

Dewatering gas wells typically exhibit a high gas–liquid ratio, making tapered electrical submersible pump (ESP) systems a common choice. However, the flow rate within the pump varies significantly along its length, and production parameters fluctuate considerably across different stages of operation for a gas reservoir. Traditional ESP sizing methods typically consider one single operating case and one single pump model. In contrast, tapered ESP systems require the designer to manually select and combine pump models, stage numbers, and operating frequencies based largely on experience. This process can be cumbersome and time-consuming. To address the limitations of existing ESP sizing methods, this study develops a computational program for ESP operation parameters stage by stage and generates extensive training data. A fully connected neural network (FCNN) based on the backpropagation (BP) algorithm is then trained on these data. The model can predict key parameters such as gas volume fraction (GVF) and flow rate along the pump, operating frequency, and total pump efficiency, using input data such as fluid parameters at the pump’s intake and discharge, as well as pump stage numbers and performance curve data. The model demonstrates high accuracy, with a mean absolute error (MAE) of 0.3431, a mean squared error (MSE) of 0.3231, and a coefficient of determination (R²) of 0.9991. By integrating a wellbore two-phase flow model and leveraging industry experience in pump sizing, a hybrid model for automatic ESP sizing under multiple working conditions is proposed, with the objective of maximizing pump efficiency. This model enables optimal pump sizing, calculates the operating frequency corresponding to given working cases, significantly reduces the workload of designers, and enhances the overall design outcomes. Full article

(This article belongs to the Section Energy Systems)

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25 pages, 6535 KiB

Open AccessArticle

ANN-Based Prediction and RSM Optimization of Radiative Heat Transfer in Couple Stress Nanofluids with Thermodiffusion Effects

by Reima Daher Alsemiry, Sameh E. Ahmed, Mohamed R. Eid and Essam M. Elsaid

Processes 2025, 13(4), 1055; https://doi.org/10.3390/pr13041055 - 1 Apr 2025

Abstract

This research investigates the impact of second-order slip conditions, Stefan flow, and convective boundary constraints on the stagnation-point flow of couple stress nanofluids over a solid sphere. The nanofluid density is expressed as a nonlinear function of temperature, while the diffusion-thermo effect, chemical [...] Read more.

This research investigates the impact of second-order slip conditions, Stefan flow, and convective boundary constraints on the stagnation-point flow of couple stress nanofluids over a solid sphere. The nanofluid density is expressed as a nonlinear function of temperature, while the diffusion-thermo effect, chemical reaction, and thermal radiation are incorporated through linear models. The governing equations are transformed using appropriate non-similar transformations and solved numerically via the finite difference method (FDM). Key physical parameters, including the heat transfer rate, are analyzed in relation to the Dufour number, velocity, and slip parameters using an artificial neural network (ANN) framework. Furthermore, response surface methodology (RSM) is employed to optimize skin friction, heat transfer, and mass transfer by considering the influence of radiation, thermal slip, and chemical reaction rate. Results indicate that velocity slip enhances flow behavior while reducing temperature and concentration distributions. Additionally, an increase in the Dufour number leads to higher temperature profiles, ultimately lowering the overall heat transfer rate. The ANN-based predictive model exhibits high accuracy with minimal errors, offering a robust tool for analyzing and optimizing the thermal and transport characteristics of couple stress nanofluids. Full article

(This article belongs to the Special Issue Advances in Computational Fluid Dynamics (CFD) Simulation of Thermal Chemical Processes)

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21 pages, 6049 KiB

Open AccessArticle

Sustainable Treatment of Amoxicillin-Contaminated Wastewater Using Fe²⁺/H₂O₂/AC: Performance, Stability, and Environmental Impact

by Sumita, Jibran Ali Ghumro, Jingzhen Su, Cong Li, Zhengming He and Jieming Yuan

Processes 2025, 13(4), 1054; https://doi.org/10.3390/pr13041054 - 1 Apr 2025

Abstract

This study investigates the activation mechanisms of hydrogen peroxide (H₂O₂) using iron-activated carbon (Fe²⁺/H₂O₂/AC) for the efficient degradation of amoxicillin (AM) in wastewater. The system achieved a high degradation efficiency of 90% under [...] Read more.

This study investigates the activation mechanisms of hydrogen peroxide (H₂O₂) using iron-activated carbon (Fe²⁺/H₂O₂/AC) for the efficient degradation of amoxicillin (AM) in wastewater. The system achieved a high degradation efficiency of 90% under alkaline conditions (pH 9), with singlet oxygen (¹O₂) and hydroxyl radicals (^•OH) identified as the dominant reactive species through scavenger experiments. High-performance liquid chromatography–mass spectrometry (HPLC-MS) analysis revealed degradation by-products and proposed reaction pathways, including the loss of amine groups, ring-opening oxidation, and bond cleavage. The structural and morphological properties of Fe²⁺/H₂O₂/AC were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analysis. The BET surface area of Fe²⁺/H₂O₂/AC was determined to be 128.36 m²/g, with a mesoporous structure facilitating efficient mass transfer and adsorption. The system was systematically evaluated under varying conditions, including H₂O₂ concentration (25–250 mg/L), catalyst dosage (0.05–1.0 mg/L), and pH (3–10). Kinetic analysis revealed that the degradation process follows pseudo-second-order kinetics (R² = 0.966), while adsorption isotherms were best described by the Langmuir model (R² = 0.98). Ecotoxicity tests indicated that the degradation products are less harmful to aquatic organisms. The system demonstrated excellent stability over three consecutive cycles, highlighting its potential for long-term application in treating pharmaceutical-contaminated wastewater. Full article

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

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33 pages, 4777 KiB

Open AccessReview

Biomass-Derived Syngas Chemical Looping Combustion Using Fluidizable Oxygen Carriers: A Review

by Hugo de Lasa and Nicolas Torres Brauer

Processes 2025, 13(4), 1053; https://doi.org/10.3390/pr13041053 - 1 Apr 2025

Abstract

This critical review evaluates chemical looping combustion using a syngas derived from gasified biomass (BMD Syngas). It is anticipated that establishing such a process will open new opportunities for CO₂ sequestration and the use of highly concentrated CO₂ in the manufacturing [...] Read more.

This critical review evaluates chemical looping combustion using a syngas derived from gasified biomass (BMD Syngas). It is anticipated that establishing such a process will open new opportunities for CO₂ sequestration and the use of highly concentrated CO₂ in the manufacturing and synthesis of fuels from entirely renewable feedstocks. This review focuses on the process conducted through using two interconnected fluidized bed units: a nickel oxide reduction unit (an endothermic Fuel Reactor) and a nickel oxidation unit (an exothermic Air Reactor). In this respect, a high-performance OC (HPOC) with Ni on a γ-Al₂O₃ fluidizable support (20wt% Ni, 1wt% Co, 5wt% La/γ-Al₂O₃) was developed at the CREC (Chemical Reactor Engineering Centre) of the University of Western Ontario, Canada. The HPOC was studied in a CREC Riser Simulator. The benefits of this mini-fluidized unit are that it can be operated at 2–40 s reaction times, 550–650 °C temperatures, 1.3–2.5 H₂/CO ratios, and 0.5–1 biomass/syngas stoichiometric ratios, mimicking the conditions of industrial-scale CLC units. When using a syngas derived from biomass and the HPOC under these operating conditions, 90% CO, 92% H₂, and 88% CH4 conversions, together with a 91% CO₂ yield, were obtained. These results allowed the prediction of a 1.84–3.0 wt% (

g_{O_{2}} / g_{O_{C}}

) oxygen transport capacity, with a 40–70% nickel oxide conversion. The experimental data acquired with the CREC Riser Simulator permitted the development of realistic kinetic models. The resulting kinetics were used in combination with Computational Particle Fluid Dynamics (CPFD) to demonstrate the operability of a large-scale industrial syngas CLC process in a downer fuel unit. In addition, these CPFD simulations were employed to corroborate that high CO₂ yields are achievable in 12–15 m length downer fuel units. Full article

(This article belongs to the Special Issue Bioenergy Production from Biomass Feedstocks)

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19 pages, 3415 KiB

Open AccessArticle

Dynamic Modeling of Heat-Integrated Air Separation Column Based on Nonlinear Wave Theory and Mass Transfer Mechanism

by Hang Zhou, Xinlei Xia and Lin Cong

Processes 2025, 13(4), 1052; https://doi.org/10.3390/pr13041052 - 1 Apr 2025

Abstract

The air separation process is an important industrial process for the production of high-purity nitrogen and oxygen, representing the level of technological development in a country’s chemical industry. It has high energy consumption but very low energy utilization efficiency. In the overall environment [...] Read more.

The air separation process is an important industrial process for the production of high-purity nitrogen and oxygen, representing the level of technological development in a country’s chemical industry. It has high energy consumption but very low energy utilization efficiency. In the overall environment of increasingly scarce global energy, the application of internal heat coupling technology in the air separation process can effectively reduce energy consumption. However, due to the low-temperature characteristics, ultra-high purity characteristics, and the nature of multi-component systems of the heat-integrated air separation column (HIASC), its modeling process and dynamic characteristic analysis are complex. To solve the disadvantages of overly complex mechanistic models and insufficient accuracy of traditional simplified models, a concentration distribution curve description method based on the mass transfer mechanism is proposed, and combined with the traditional wave theory, a nonlinear wave model of the HIASC is established. Based on this model, static and dynamic analyses were carried out, and the research results prove that the newly established nonlinear wave model maintains high accuracy while simplifying the model complexity. It can not only accurately track the concentration changes of key products but also fully reflect various typical nonlinear characteristics of the system. Compared to the mechanism model, the wave model can reduce the running time by approximately 20%, thereby improving operational efficiency. This method explains various characteristics of the system from a perspective different from that of the mechanistic model. Full article

(This article belongs to the Special Issue Heat and Mass Transfer Phenomena in Energy Systems)

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18 pages, 4317 KiB

Open AccessArticle

Fluorescence-Based Detection of Picric Acid Using Vortex-Assisted Liquid–Liquid Microextraction: An Innovative Analytical Approach

by Sofia Kakalejčíková, Dominik Harenčár, Yaroslav Bazeľ and Maksym Fizer

Processes 2025, 13(4), 1051; https://doi.org/10.3390/pr13041051 - 1 Apr 2025

Abstract

A novel design for vortex-assisted liquid–liquid microextraction (VALLME), combined with spectrofluorimetric determination (FLD), was proposed and successfully tested for determining picric acid (PA) in water samples. This fluorescence method is based on the formation of an ion associate (IA) through electrostatic interactions, which [...] Read more.

A novel design for vortex-assisted liquid–liquid microextraction (VALLME), combined with spectrofluorimetric determination (FLD), was proposed and successfully tested for determining picric acid (PA) in water samples. This fluorescence method is based on the formation of an ion associate (IA) through electrostatic interactions, which serves as the analytical species for fluorescence measurement in the presence of the basic polymethine dye Astrafloksin (AF). The approach aims to minimize the volume of the extraction phase, aligning with the principles of green analytical chemistry. The calibration curve was linear from 0.92 to 11.45 µg L⁻¹, with an R² of 0.9930. LOD was 0.40 µg L⁻¹. Density functional theory (DFT) calculations, supported by analysis of van der Waals and electrostatic interionic attraction, helped explain the experimentally observed selectivity of the AF cation for picrate compared to other selected phenols. Theoretical solubility descriptors of the proposed IA provided insight into the extraction of IA from water to the n-amyl acetate phase. This VALLME-FLD method represents a significant advancement in PA determination, characterized by high sensitivity, selectivity, and procedural simplicity. It minimizes the use of organic solvents, facilitates direct sample preparation, and shortens analysis time. The developed method was successfully applied to real samples. Full article

(This article belongs to the Special Issue Advanced Green Analytical Chemistry for Environmental Pollutants Detection)

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14 pages, 2636 KiB

Open AccessArticle

by Jialei Liu, Yuqing Chen, Haifeng Gu, Yinxing Zhang, Wei Wang and Hongguang Xiao

Processes 2025, 13(4), 1050; https://doi.org/10.3390/pr13041050 - 1 Apr 2025

Abstract

To address the challenge of heat transfer enhancement in the condensation of steam with non-condensable gases on a vertical wall under natural convection conditions, an improved boundary layer model with coupled multi-physics field was proposed in this paper, and traditional theoretical limitations were [...] Read more.

To address the challenge of heat transfer enhancement in the condensation of steam with non-condensable gases on a vertical wall under natural convection conditions, an improved boundary layer model with coupled multi-physics field was proposed in this paper, and traditional theoretical limitations were broken through by innovations. The particle swarm optimization algorithm was first introduced into the solution of the condensation boundary layer, and the convergence difficulty in the laminar–turbulent transition region under infinite boundary conditions was overcome. A coupled momentum–energy–mass equation system that simultaneously considered temperature–concentration dual-driven gravity terms and liquid film drag–suction dual effects was established, and higher computational efficiency and accuracy were achieved. A new mechanism where the concentration boundary layer dominated heat transfer resistance under the coupled action of the Prandtl number (Pr) and Schmidt number (Sc) was revealed. Experimental validation demonstrated that a prediction error of less than 5% was exhibited by the model under typical operating conditions of passive containment cooling systems (pressures of 1.5–4.5 atm and subcooling temperatures of 14–36 °C), and a theoretical tool for high-precision condensation heat transfer design was provided. Full article

(This article belongs to the Section Chemical Processes and Systems)

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22 pages, 3878 KiB

Open AccessArticle

Precision Prediction Strategy for Renewable Energy Power in Power Systems—A Physical-Knowledge Integrated Model

by Shenbing Hua, Shuanglong Jin, Zongpeng Song, Xiaolin Liu, Shu Wang and Hengrui Ma

Processes 2025, 13(4), 1049; https://doi.org/10.3390/pr13041049 - 1 Apr 2025

Abstract

To promote energy transformation and upgrading and achieve the dual carbon strategic goals, the proportion of renewable energy generation in China has been increasing annually. Among them, wind and photovoltaic power generation play a significant role in renewable energy generation due to their [...] Read more.

To promote energy transformation and upgrading and achieve the dual carbon strategic goals, the proportion of renewable energy generation in China has been increasing annually. Among them, wind and photovoltaic power generation play a significant role in renewable energy generation due to their widely distributed energy sources, and their development has been particularly rapid. However, renewable energy generation exhibits strong volatility, and the integration of a large amount of renewable energy into the power grid poses a threat to the stable operation of the power system. Therefore, renewable energy power prediction is of great significance for the safe and stable operation of the power system. This paper proposes a physical-knowledge integrated renewable energy power prediction model. Firstly, the Fuzzy C-Means (FCM) method is used to handle missing data. Then, the variational mode decomposition (VMD) algorithm is applied to decompose the renewable energy power into high-frequency and low-frequency components. The high-frequency components are input into a Convolutional Neural Network (CNN) model, while the low-frequency components are input into a Long Short-Term Memory (LSTM) neural network for training and prediction. Finally, the effectiveness and feasibility of the proposed method in this paper are verified through real data from a certain actual power grid. After analysis, the proposed method demonstrates a prediction accuracy improvement of up to 5.71% compared to conventional approaches. Simultaneously, in high-noise interference environments, the prediction error can be reduced by up to 11.16%. Full article

(This article belongs to the Topic Advanced Operation, Control, and Planning of Intelligent Energy Systems)

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19 pages, 3736 KiB

Open AccessArticle

Radiation and Combustion Effects of Hydrogen Enrichment on Biomethane Flames

by Francisco Elmo Lima Uchoa Filho, Helton Carlos Marques Sampaio, Claudecir Fernandes de Freitas Moura Júnior, Mona Lisa Moura de Oliveira, Jesse Van Griensven Thé, Paulo Alexandre Costa Rocha and André Valente Bueno

Processes 2025, 13(4), 1048; https://doi.org/10.3390/pr13041048 - 1 Apr 2025

Abstract

Hydrogen has been presented as a promising energy vector in decarbonized economies. Its singular properties can affect important aspects of industrial flames, such as the temperature, emissions, and radiative/convective energy transfer balance, thus requiring in-depth studies to optimize combustion processes using this fuel [...] Read more.

Hydrogen has been presented as a promising energy vector in decarbonized economies. Its singular properties can affect important aspects of industrial flames, such as the temperature, emissions, and radiative/convective energy transfer balance, thus requiring in-depth studies to optimize combustion processes using this fuel isolate or in combination with other renewable alternatives. This work aims to conduct a detailed numerical analysis of temperatures and gas emissions in the combustion of biomethane enriched with different proportions of hydrogen, with the intent to contribute to the understanding of the impacts of this natural gas surrogate on practical combustion applications. RANS k-

ω

and k-

ϵ

turbulence models were combined with the GRI Mech 3.0, San Diego, and USC mechanisms using the ANSYS-Fluent 2024-R2 softwareto evaluate its performance regarding flame prediction. The Moss–Brookes model was adopted to predict soot formation for the methane flames by solving transport equations for normalized radical nuclei concentration and the soot mass fraction. The Discrete Ordinates (DOs) method with gray band model was applied to solve the Radiation Transfer Equation (RTE). The results of the experiments and numerical simulations highlight the importance of carefully selecting turbulence and chemical kinetics models for an accurate representation of real-scale industrial burners. Relative mean errors of 1.5% and 6.0% were registered for temperature and pollutants predictions, respectively, with the USD kinetics scheme and k-

o m e g a

turbulence model presenting the most accurate results. The operational impacts of hydrogen enrichment of biomethane flames were accessed for a practical combustion system. With 15% of hydrogen blending, the obtained results indicate a 73% penalty in CO emissions, an increase of 6% in NO emissions, and a 34 K flame temperature increase. Also, a reduction in flame radiation due to hydrogen enrichment was observed for hydrogen concentrations above 20%, a behavior that can affect practical combustion systems such as those in glass and other ceramics industries. Full article

(This article belongs to the Special Issue Biomass to Renewable Energy Processes, 2nd Edition)

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