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Processes, Volume 12, Issue 5 (May 2024) – 196 articles

Cover Story (view full-size image): The increasing global population and the climate crisis both highlight the need for sustainable solutions, such as microalgae, which offer high-quality proteins and bioactive compounds for food, feed, and biofuel. However, the water-intensive nature of microalgae cultivation poses challenges. This study explores a water reuse strategy for cultivating two Chlorophyta microalgae, Pseudococcomyxa simplex and Chlorella vulgaris, in batch mode. The results show that P. simplex can maintain growth and chlorophyll content with 70% medium reuse across three cycles, whereas C. vulgaris exhibits a significant decline in growth under similar conditions. View this paper
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25 pages, 5299 KiB  
Article
Supercritical CO2-Based Extraction and Detection of Phenolic Compounds and Saponins from the Leaves of Three Medicago varia Mart. Varieties by Tandem Mass Spectrometry
by Mayya P. Razgonova, Muhammad Amjad Nawaz, Elena P. Ivanova, Elena I. Cherevach and Kirill S. Golokhvast
Processes 2024, 12(5), 1041; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051041 - 20 May 2024
Viewed by 533
Abstract
A comparative metabolomic study of three varieties of alfalfa (Medicago varia Mart.) was performed via extraction with supercritical carbon dioxide modified with ethanol (EtOH) and the detection of bioactive compounds via tandem mass spectrometry. Several experimental conditions were investigated in the pressure [...] Read more.
A comparative metabolomic study of three varieties of alfalfa (Medicago varia Mart.) was performed via extraction with supercritical carbon dioxide modified with ethanol (EtOH) and the detection of bioactive compounds via tandem mass spectrometry. Several experimental conditions were investigated in the pressure range of 50–250 bar, with ethanol used as a co-solvent in an amount of 1% of the total volume in the liquid phase at a temperature in the range of 31–70 °C. The most effective extraction conditions were as follows: a pressure of 250 Bar and a temperature of 60 °C for M. varia. M. varia contains various phenolic compounds and sulfated polyphenols with valuable biological activity. Tandem mass spectrometry (HPLC-ESI–ion trap) was applied to detect the target analytes. A total of 103 bioactive compounds (59 polyphenols and 44 compounds belonging to other chemical groups) were tentatively identified in extracts from aerial parts of alfalfa. For the first time, twenty-one chemical constituents from the polyphenol group (flavones: Formononetin, Chrysoeriol, Cirsimaritin, Cirsiliol, Cirsilineol, tricin-O-hexoside, Apigenin C-glucose C-deoxyhexoside, Apigenin 7-O-diglucuronide, 2′-Hydroxygenistein 4′,7-O-diglucoside, etc.) and six from other chemical groups (saponins: Soyasaponin II, Soyasaponin gamma g, Soyasaponin I, Soyasaponin Bd, Soyaysaponin beta g, etc.) were identified in the aerial parts of M. varia. Full article
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17 pages, 5750 KiB  
Article
Research on the Interaction Mechanism of Multi-Fracture Propagation in Hydraulic Fracturing
by Lin-Peng Zhang, Tuan Gu, Bin Li and Peng Zheng
Processes 2024, 12(5), 1040; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051040 - 20 May 2024
Viewed by 626
Abstract
During the hydraulic-fracturing process, stress interference occurs among multiple wells and fractures, potentially affecting the trajectory of hydraulic fracture propagation. Previous studies have largely overlooked the influence of proppant support stresses on the trajectories of fracture propagation. This paper establishes a mathematical model, [...] Read more.
During the hydraulic-fracturing process, stress interference occurs among multiple wells and fractures, potentially affecting the trajectory of hydraulic fracture propagation. Previous studies have largely overlooked the influence of proppant support stresses on the trajectories of fracture propagation. This paper establishes a mathematical model, grounded in the boundary element method, designed to compute the propagation of multiple fractures, considering both proppant support on the fracture surface and dynamic perturbations within the local stress field. The findings of this research reveal that the stress field induced by hydraulic fracturing exhibits dynamic evolution characteristics, necessitating a comprehensive study of the fracture initiation and extension across the entire fracturing time domain. The effect of the residual fracture width under proppant action on the in situ stress field cannot be ignored. During simultaneous fracturing, hydraulic fractures are inclined to propagate in the direction of the maximum horizontal principal stress, particularly as the in situ differential stress escalates. Staggered fracturing between wells has been proven to be more effective than head-to-head fracturing. Simply increasing the well spacing cannot solve the problem of inter-well fracture interference. In zipper fracturing, adjusting the fracturing sequence can inhibit the fracture intersections between wells, thereby controlling the trajectory of fracture propagation. The aforementioned research has considerable significance in guiding the control of fracture morphology during hydraulic-fracturing processes. Full article
(This article belongs to the Special Issue Numerical Simulations of Fracturing in Petroleum Engineering)
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18 pages, 10994 KiB  
Article
Robust Forest Fire Detection Method for Surveillance Systems Based on You Only Look Once Version 8 and Transfer Learning Approaches
by Nodir Yunusov, Bappy MD Siful Islam, Akmalbek Abdusalomov and Wooseong Kim
Processes 2024, 12(5), 1039; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051039 - 20 May 2024
Viewed by 715
Abstract
Forest fires have emerged as a significant global concern, exacerbated by both global warming and the expanding human population. Several adverse outcomes can result from this, including climatic shifts and greenhouse effects. The ramifications of fire incidents extend widely, impacting human communities, financial [...] Read more.
Forest fires have emerged as a significant global concern, exacerbated by both global warming and the expanding human population. Several adverse outcomes can result from this, including climatic shifts and greenhouse effects. The ramifications of fire incidents extend widely, impacting human communities, financial resources, the natural environment, and global warming. Therefore, timely fire detection is essential for quick and effective response and not to endanger forest resources, animal life, and the human economy. This study introduces a forest fire detection approach utilizing transfer learning with the YOLOv8 (You Only Look Once version 8) pretraining model and the TranSDet model, which integrates an improved deep learning algorithm. Transfer Learning based on pre-trained YoloV8 enhances a fast and accurate object detection aggregate with the TranSDet structure to detect small fires. Furthermore, to train the model, we collected 5200 images and performed augmentation techniques for data, such as rotation, scaling, and changing due and saturation. Small fires can be detected from a distance by our suggested model both during the day and at night. Objects with similarities can lead to false predictions. However, the dataset augmentation technique reduces the feasibility. The experimental results prove that our proposed model can successfully achieve 98% accuracy to minimize catastrophic incidents. In recent years, the advancement of deep learning techniques has enhanced safety and secure environments. Lastly, we conducted a comparative analysis of our method’s performance based on widely used evaluation metrics to validate the achieved results. Full article
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16 pages, 9384 KiB  
Article
Structural Analysis of Thermal Diffusion and Non-Uniform Temperature Distribution along the Sidewall Thickness of STS316L during Gas Tungsten Arc Butt Welding
by Taehyung Na, Gwang-Ho Jeong, Kiyoung Kim, Yongdeog Kim, Junsung Bae, Seonmin Kim, Sang-Hyun Ahn, Seung-Hoon Bae, Sang-Kyo Kim and Dae-Won Cho
Processes 2024, 12(5), 1038; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051038 - 20 May 2024
Viewed by 523
Abstract
This study investigated how welding affects the thermal deformation of square cells produced for casks, which are dry storage containers for spent nuclear fuel. We aimed to minimize structural deformation by utilizing STS316L as the material for the square cells. We explored a [...] Read more.
This study investigated how welding affects the thermal deformation of square cells produced for casks, which are dry storage containers for spent nuclear fuel. We aimed to minimize structural deformation by utilizing STS316L as the material for the square cells. We explored a method of subdividing the square cells and joining them through butt welding. Keeping the upper plate thickness constant, GTA butt welding was conducted while varying the column’s wall thickness, followed by measurement with a laser vision sensor. The heat conduction and thermal strain were then calculated using a finite element analysis (FEM). Both experimental and analytical results confirmed that there was significant thermal deformation in the cases of thick-walled columns due to variations in heat conduction distribution, with the resulting deformation patterns depending on thickness. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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18 pages, 7534 KiB  
Article
Design Method of Cam Steering Mechanism Based on Path Fitting
by Xiaofei Zheng, Hantao Zhao, Songhui Zhang, Dan Liu and Binrui Wang
Processes 2024, 12(5), 1037; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051037 - 20 May 2024
Viewed by 487
Abstract
In order to improve the accuracy of a solar-powered punch card car’s movement on a designated route and reduce positional deviations during its operation, a solar-powered punch card car with a single cam as the steering guidance mechanism was designed. The car adopts [...] Read more.
In order to improve the accuracy of a solar-powered punch card car’s movement on a designated route and reduce positional deviations during its operation, a solar-powered punch card car with a single cam as the steering guidance mechanism was designed. The car adopts a three-wheel structure. The transmission mechanism, steering mechanism, driving mechanism, and regulating mechanism of the car were analyzed. The kinematics model of the car was established and the motion characteristics of the car were obtained. By analyzing the relationship between the steering angle of the car and the curvature radius of its travel route, the front wheel angle of the car at each position was calculated using MATLAB R2020a. This allowed us to establish the relationship between the front wheel angle and the displacement of the steering push rod, which was further converted into the theoretical contour line of the cam. Subsequently, the theoretical contour line of the cam was completed and envelope correction was performed. Finally, through mechanical analysis and experimental verification using a prototype, the results indicated that the single-cam steering guidance mechanism calculated using this fast path fitting method exhibited excellent mechanical performance and a smooth and accurate trajectory, and the traveling path of the theoretical cam contour curve was basically consistent with the actual trajectory route. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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19 pages, 3365 KiB  
Article
Optimizing Accumulator Performance in Hydraulic Systems through Support Vector Regression and Rotational Factors
by Zilong Xu, Juan Zhou, Hu Chen, Bo Xu and Zhengxiang Shen
Processes 2024, 12(5), 1036; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051036 - 20 May 2024
Viewed by 423
Abstract
The piston-type accumulator is an energy storage device in hydraulic–pneumatic systems, playing a significant role in industries such as petrochemicals, heavy machinery, and steel metallurgy. The displacement parameters of the piston-type accumulator are vitally important for fault diagnosis and early warning in hydraulic [...] Read more.
The piston-type accumulator is an energy storage device in hydraulic–pneumatic systems, playing a significant role in industries such as petrochemicals, heavy machinery, and steel metallurgy. The displacement parameters of the piston-type accumulator are vitally important for fault diagnosis and early warning in hydraulic systems. Traditional displacement measurement methods cannot meet the requirements of the internal testing environment of the accumulator. Therefore, this paper proposes an accumulator piston displacement signal compensation method based on rotational factors and support vector regression. Firstly, empirical mode decomposition is utilized to denoise the signal. Then, rotational factors are used to generate a delay compensation module to compensate for the signal attenuation and time delay caused by metallic reflection and scattering within the cylinder of the radar signal. The support vector regression model is improved based on a hash table to enhance its computational efficiency and achieve radar displacement signal compensation. Finally, a simulation experiment is designed to verify the effectiveness of the proposed method. Full article
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13 pages, 1493 KiB  
Article
Impact of TEMPO-Oxidation Pretreatment of Red Ginseng Residual on Nanofibrillation
by Audrey Zahra, Virginia Ghita Firsty and Soo-Jeong Shin
Processes 2024, 12(5), 1035; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051035 - 20 May 2024
Viewed by 496
Abstract
Red ginseng extract is one of the most widely used herbal medicines to prevent and cure various diseases. Among the processed products derived from red ginseng, the water-insoluble part as red ginseng residual (RGR) becomes waste, even though it contains important ingredients. TEMPO-oxidation [...] Read more.
Red ginseng extract is one of the most widely used herbal medicines to prevent and cure various diseases. Among the processed products derived from red ginseng, the water-insoluble part as red ginseng residual (RGR) becomes waste, even though it contains important ingredients. TEMPO-oxidation (TO) can be used as a pre-treatment with different degrees of oxidation (DO) (0 to 0.4) in red ginseng residual (RGR-TO) by introducing chemical oxidation and high-pressure homogenizer (HPH) as a nanofibrillation process. 1H NMR was used to determine the carbohydrate composition and calculate DO, size was examined using a nanoparticle analyzer, and the zeta potential was used to determine surface charge density. RGR-TO with different concentrations had different compositions; glucose and uronic acid were the main ingredients. All treated RGR-TO showed higher oxidant levels than the untreated counterpart (RGR-TO 0). As the oxidant levels increased, the zeta potential and uronic acid increased, but the size of the nanofibril from RGR-TO decreased. The results of this study showed that TEMPO-oxidation pretreatment was effective in producing RGR cellulose nanofibril (CNF) with a variety of properties by adjusting the level of oxidation pretreatment and the number of HPH passes. Full article
(This article belongs to the Special Issue Advances in Value-Added Products from Waste)
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8 pages, 182 KiB  
Editorial
Oil and Gas Well Engineering Measurement and Control
by Tianshou Ma and Yuqiang Xu
Processes 2024, 12(5), 1034; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051034 - 20 May 2024
Viewed by 574
Abstract
Oil and gas wells represent a unique channel in regard to oil and gas exploration and production [...] Full article
(This article belongs to the Special Issue Oil and Gas Well Engineering Measurement and Control)
16 pages, 1348 KiB  
Article
Integration of Chemical Looping Combustion to a Gasified Stream with Low Hydrogen Content
by Guadalupe S. Fraga-Cruz, Mario A. Pérez-Méndez, Gladys Jiménez-García, Rafael Huirache-Acuña, Fabricio Nápoles-Rivera, Jaime Espino-Valencia and Rafael Maya-Yescas
Processes 2024, 12(5), 1033; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051033 - 19 May 2024
Viewed by 500
Abstract
Global population growth requires the use of various natural resources to satisfy the basic needs of humanity. Fossil fuels are mainly used to produce electricity, transportation and the artificial air conditioning of habitats. Nevertheless, countries around the world are looking for alternative energy [...] Read more.
Global population growth requires the use of various natural resources to satisfy the basic needs of humanity. Fossil fuels are mainly used to produce electricity, transportation and the artificial air conditioning of habitats. Nevertheless, countries around the world are looking for alternative energy sources due to the decrease in the availability of these fuels and their high environmental impact. The mixture of hydrogen and carbon monoxide (H2 + CO), commonly called syngas, is a high-value feedstock for various industrial applications. By varying the composition of syngas, especially the H2/CO molar ratio, it can be used to produce methanol, fuels or synthetic natural gas. However, when this ratio is very low, the separation of this gas usually represents a great problem when making the energy balance, which is why it is proposed to adapt a combustion process in chemical cycles, taking advantage of the energy of this gas, reducing the energy impact of the process. During the present project, mass and energy balances were developed for combustion in chemical cycles, using ilmenite as a carrier, integrating heat exchangers to take advantage of the residual energy at the output of the process, to preheat the inlet current in the regenerator. Here, a comparative was made at different temperatures of the air stream and evaluating the mechanism of the ilmenite when a syngas stream is used as fuel. Full article
(This article belongs to the Special Issue Technological Processes for Chemical and Related Industries)
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22 pages, 5413 KiB  
Article
Adsorbent Biomaterials Based on Natural Clays and Orange Peel Waste for the Removal of Anionic Dyes from Water
by Sonia Mihai, Andreea Bondarev, Cătalina Călin and Elena-Emilia Sȋrbu
Processes 2024, 12(5), 1032; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051032 - 19 May 2024
Viewed by 552
Abstract
This study demonstrates the efficient removal of Alizarin Yellow R anionic dye (AY) from aqueous solutions using green adsorbents. Natural kaolin clay (A1), acid-modified natural clay (A2), chemically treated orange peel (C1) and biochar produced by the thermal treatment of orange peel (C2) [...] Read more.
This study demonstrates the efficient removal of Alizarin Yellow R anionic dye (AY) from aqueous solutions using green adsorbents. Natural kaolin clay (A1), acid-modified natural clay (A2), chemically treated orange peel (C1) and biochar produced by the thermal treatment of orange peel (C2) were tested for the adsorption of AY. The characteristics of the sorbents were determined by instrumental methods: SEM, EDS, FTIR, BET and TGA. The adsorption experiments were performed under different conditions, including the initial AY dye concentration, adsorbent weight, pH, temperature and contact time. The maximum adsorption capacities had values between 15.72 and 74.62 mg/g at 298 K and the optimal pH of 6.5 at initial concentrations ranging from 30 to 70 mg/L for all adsorbents. The equilibrium data were used for the adsorption isotherm models: Freundlich, Langmuir and Temkin. The Freundlich model fit best for the adsorbents A2, C1 and C2, and the Langmuir isotherm had the highest regression value for the adsorbent A1 (R2 = 0.9935). Thermodynamic parameters indicated the spontaneous and favorable adsorption process of AY. A study of the adsorption kinetics proved that they best fit the pseudo-second-order model, with the highest coefficients of determination (R2), outperforming the pseudo-first-order model. The results of this study indicate the potential for the valorization of locally available clays and orange peel waste in the purification processes of water. Full article
(This article belongs to the Section Environmental and Green Processes)
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12 pages, 880 KiB  
Article
Response Surface Methodology: An Optimal Design for Maximising the Efficiency of Microwave-Assisted Extraction of Total Phenolic Compounds from Coriandrum sativum Leaves
by Soraya Hihat, Noureddine Touati, Abdelhakim Sellal and Khodir Madani
Processes 2024, 12(5), 1031; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051031 - 19 May 2024
Viewed by 774
Abstract
The optimization of total phenolic compounds (TPC) extraction yield and maximization of total antioxidant capacity (TAC) from coriander leaves were investigated using response surface methodology. The extraction of TPC was carried out using microwave-assisted extraction. A Box-Behnken design was used to study the [...] Read more.
The optimization of total phenolic compounds (TPC) extraction yield and maximization of total antioxidant capacity (TAC) from coriander leaves were investigated using response surface methodology. The extraction of TPC was carried out using microwave-assisted extraction. A Box-Behnken design was used to study the effects of the three independent variables, solvent concentration (ethanol/water 20–80%), microwave power (100–500 watt) and irradiation time (30–150 s) on the response. A second-order polynomial model was used to predict the reaction. The regression analysis showed that about 99% of the variations could be explained by the models. The predicted values were 50.97 GAE/g dw and 5.75 mg GAE/g dw for TPC and TAC, respectively. The reaction surface analysis showed that the optimum extraction parameters that maximized the extraction of antioxidants yield were 52.62% ethanol, 452.12 watt and 150 s. Under optimal conditions, the experimental values for TPC and TAC were 49.63 ± 0.93 mg GAE/g dw and 5.55 ± 0.07 mg GAE/g dw, respectively. The experimental values are in agreement with the predicted values, indicating the suitability of the model used and the success of the response surface methodology in optimizing the extraction conditions. Full article
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21 pages, 1816 KiB  
Article
Improving Polyp Segmentation with Boundary-Assisted Guidance and Cross-Scale Interaction Fusion Transformer Network
by Lincen Jiang, Yan Hui, Yuan Fei, Yimu Ji and Tao Zeng
Processes 2024, 12(5), 1030; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051030 - 19 May 2024
Viewed by 400
Abstract
Efficient and precise colorectal polyp segmentation has significant implications for screening colorectal polyps. Although network variants derived from the Transformer network have high accuracy in segmenting colorectal polyps with complex shapes, they have two main shortcomings: (1) multi-level semantic information at the output [...] Read more.
Efficient and precise colorectal polyp segmentation has significant implications for screening colorectal polyps. Although network variants derived from the Transformer network have high accuracy in segmenting colorectal polyps with complex shapes, they have two main shortcomings: (1) multi-level semantic information at the output of the encoder may result in information loss during the fusion process and (2) failure to adequately suppress background noise during segmentation. To address these challenges, we propose a cross-scale interaction fusion transformer for polyp segmentation (CIFFormer). Firstly, a novel feature supplement module (FSM) supplements the missing details and explores potential features to enhance the feature representations. Additionally, to mitigate the interference of background noise, we designed a cross-scale interactive fusion module (CIFM) that combines feature information between different layers to obtain more multi-scale and discriminative representative features. Furthermore, a boundary-assisted guidance module (BGM) is proposed to help the segmentation network obtain boundary-enhanced details. Extensive experiments on five typical datasets have demonstrated that CIFFormer has an obvious advantage in segmenting polyps. Specifically, CIFFormer achieved an mDice of 0.925 and an mIoU of 0.875 on the Kvasir-SEG dataset, achieving superior segmentation accuracy to competing methods. Full article
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12 pages, 2152 KiB  
Article
Improving Microalgae Feasibility Cultivation: Preliminary Results on Exhausted Medium Reuse Strategy
by Luigi Marra, Elena Aurino, Francesca Raganati, Antonino Pollio and Antonio Marzocchella
Processes 2024, 12(5), 1029; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051029 - 19 May 2024
Viewed by 581
Abstract
Although microalgae exploitation is very promising, process sustainability is undermined by biomass production and harvesting. Among the various bottlenecks of the production process, particular attention should be paid to the water footprint. Indeed, a huge volume of water is required in microalgae production. [...] Read more.
Although microalgae exploitation is very promising, process sustainability is undermined by biomass production and harvesting. Among the various bottlenecks of the production process, particular attention should be paid to the water footprint. Indeed, a huge volume of water is required in microalgae production. Water reuse can support both the water footprint and medium cost reduction, saving water and unconverted substrates. The present study reports preliminary results regarding the utilization of a water reuse strategy for two Chlorophyta microalgae under batch conditions. Growth parameters and chlorophyll content are monitored and the optimal amount of reused medium is assessed. The results show that 70% of the medium can be reused with no loss of specific growth rate and chlorophyll fraction for Pseudococcomyxa simplex in three consecutive batch cultivations. By contrast, a significant decline in Chlorella vulgaris growth was observed after the first cultivation in reused medium, across all tested conditions. Full article
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22 pages, 7400 KiB  
Article
Predictive Modeling for Microchannel Flow Boiling Heat Transfer under the Dual Effect of Gravity and Surface Modification
by Haoxian Wu, Shengnan Zhou, Dongwei Wang, Yunbo Yang, Linglin Liu, Huijie Mao and Bifen Shu
Processes 2024, 12(5), 1028; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051028 - 19 May 2024
Viewed by 431
Abstract
This paper investigates the heat transfer performance of flow boiling in microchannels under the dual effect of gravity and surface modification through both experimental studies and mechanistic analysis. Utilizing a test bench with microchannels featuring surfaces of varying wettability levels and adjustable flow [...] Read more.
This paper investigates the heat transfer performance of flow boiling in microchannels under the dual effect of gravity and surface modification through both experimental studies and mechanistic analysis. Utilizing a test bench with microchannels featuring surfaces of varying wettability levels and adjustable flow directions, multiple experiments on R134-a flow boiling heat transfer under the effects of gravity and surface modification were conducted, resulting in 1220 sets of experimental data. The mass flux ranged from 735 kg/m2s to 1271 kg/m2s, and the heating heat flux density ranged from 9 × 103 W/m2 to 46 × 103 W/m2. The experimental results revealed the differences in the influence of different gravity and surface modification conditions on heat transfer performance. It was found that the heat transfer performance of super-hydrophilic surfaces in horizontal flow is optimal and more stable heat transfer performance is observed when gravity is aligned with the flow direction. And the impact of gravity and surface modification on heat transfer has been explained through mechanistic analysis. Therefore, two new dimensionless numbers, Fa and Conew, were introduced to characterize the dual effects of gravity and surface modification on heat transfer. A new heat transfer model was developed based on these effects, and the prediction error of the heat transfer coefficient was reduced by 12–15% compared to existing models, significantly improving the prediction accuracy and expanding its application scope. The applicability and accuracy of the new model were also validated with other experimental data. Full article
(This article belongs to the Section Energy Systems)
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26 pages, 12228 KiB  
Article
The Inversion Method of Shale Gas Effective Fracture Network Volume Based on Flow Back Data—A Case Study of Southern Sichuan Basin Shale
by Dengji Tang, Jianfa Wu, Jinzhou Zhao, Bo Zeng, Yi Song, Cheng Shen, Lan Ren, Yongzhi Huang and Zhenhua Wang
Processes 2024, 12(5), 1027; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051027 - 18 May 2024
Viewed by 527
Abstract
Fracture network fracturing is pivotal for achieving the economical and efficient development of shale gas, with the connectivity among fracture networks playing a crucial role in reservoir stimulation effectiveness. However, flow back data that reflect fracture network connectivity information are often ignored, resulting [...] Read more.
Fracture network fracturing is pivotal for achieving the economical and efficient development of shale gas, with the connectivity among fracture networks playing a crucial role in reservoir stimulation effectiveness. However, flow back data that reflect fracture network connectivity information are often ignored, resulting in an inaccurate prediction of the effective fracture network volume (EFNV). The accurate calculation of the EFNV has become a key and difficult issue in the field of shale fracturing. For this reason, the accurate shale gas effective fracture network volume inversion method needs to be improved. Based on the flow back characteristics of fracturing fluids, a tree-shaped fractal fracture flow back mathematical model for inversion of EFNV was established and combined with fractal theory. A genetic algorithm workflow suitable for EFNV inversion of shale gas was constructed based on the flow back data after fracturing, and the fracture wells in southern Sichuan were used as an example to carry out the EFNV inversion. The reliability of the inversion model was verified by testing production, cumulative gas production, and microseismic results. The field application showed that the inversion method proposed in this paper can obtain tree-shaped fractal fracture network structure parameters, fracture system original pressure, matrix gas breakthrough pressure, fracture compressibility coefficient, reverse imbibition index, equivalent main fracture half length, and effective initial fracture volume (EIFV). The calculated results of the model belong to the same order of magnitude as those of the HD model and Alkouh model, and the model has stronger applicability. This research has important theoretical guiding significance and field application value for improving the accuracy of the EFNV calculation. Full article
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24 pages, 6228 KiB  
Article
Optimizing Microwave-Assisted Extraction from Levisticum officinale WDJ Koch Roots Using Pareto Optimal Solutions
by Michał Plawgo, Sławomir Kocira and Andrea Bohata
Processes 2024, 12(5), 1026; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051026 - 18 May 2024
Viewed by 408
Abstract
The current research trend is not only focused on advanced techniques to intensify the extraction of bioactive compounds from plants, but also on the optimization process. The objective of this work was the implementation of the multiple criteria analysis using navigation on Pareto [...] Read more.
The current research trend is not only focused on advanced techniques to intensify the extraction of bioactive compounds from plants, but also on the optimization process. The objective of this work was the implementation of the multiple criteria analysis using navigation on Pareto sets to determine the optimal parameters for the microwave-assisted extraction of Levisticum officinale WDJ Koch roots in order to obtain the maximum efficiency of the antioxidant potential of the extracts. The optimized parameters were extraction time, microwave power, and plant biomass/solvent ratio, while the evaluation criteria were based on the total phenols, flavonoids, reducing sugars, and antioxidant capacity. It was shown that the process parameters analyzed, i.e., biomass/solvent ratio, process time, and microwave power, determined the extraction efficiency of total phenolic content (TPC). A different observation was made for the analysis of total flavonoid content (TFC) and total antioxidant potential (TAA). Compared to the assessment of TFC and TAA, a completely different trend was observed for the analysis of total reducing sugars (RSC). Sets of Pareto optimal, compromise, and preferred solutions were identified that will maximize the efficiency of the extraction of bioactive compounds from biomass. Due to the determined number of Pareto optimal solutions, an approach related to the introduction of preferences in the optimization procedure was applied. It was shown that for a satisfactory level of bioactive compounds, extraction should be carried out at a maximum microwave power of 750 W. Preferred solutions were obtained for root biomass to water ratios ranging from 0.0536 g/mL to 0.0679 g/mL. The preferred optimal time for microwave-assisted water extraction ranged from 64.2857 to 85.7143 s. Full article
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12 pages, 3210 KiB  
Article
Improving Ammonia Emission Model of Urea Fertilizer Fluidized Bed Granulation System Using Particle Swarm Optimization for Sustainable Fertilizer Manufacturing Practice
by Norhidayah Mohamad, Nor Azlina Ab. Aziz, Anith Khairunnisa Ghazali and Mohd Rizal Salleh
Processes 2024, 12(5), 1025; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051025 - 18 May 2024
Viewed by 565
Abstract
Granulation is an important class of production processes in food, chemical and pharmaceutical manufacturing industries. In urea fertilizer manufacturing, fluidized beds are often used for the granulation system. However, the granulation processes release ammonia to the environment. Ammonia gas can contribute to eutrophication, [...] Read more.
Granulation is an important class of production processes in food, chemical and pharmaceutical manufacturing industries. In urea fertilizer manufacturing, fluidized beds are often used for the granulation system. However, the granulation processes release ammonia to the environment. Ammonia gas can contribute to eutrophication, which is an oversupply of nitrogen and acidification to the ecosystems. Eutrophication may cause major disruptions of aquatic ecosystems. It is estimated that global ammonia emissions from urea fertilizer processes are approximately at 10 to 12 Tg N/year, which represents 23% of overall ammonia released globally. Therefore, accurate modeling of the ammonia emission by the urea fertilizer fluidized bed granulation system is important. It allows for the system to be operated efficiently and within sustainable condition. This research attempts to optimize the model of the system using the particle swarm optimization (PSO) algorithm. The model takes pressure (Mpa), binder feed rate (rpm) and inlet temperature (°C) as the manipulated variables. The PSO searches for the model’s optimal coefficients. The accuracy of the model is measured using mean square error (MSE) between the model’s simulated value and the actual data of ammonia released which is collected from an experiment. The proposed method reduces the MSE to 0.09727, indicating that the model can accurately simulate the actual system. Full article
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16 pages, 1608 KiB  
Article
The Storage Process of Electric Energy Produced from Renewable Sources from Hydrogen to Domestic Hot Water Heating
by Dorel Stoica, Lucian Mihăescu, Gheorghe Lăzăroiu and George Cristian Lăzăroiu
Processes 2024, 12(5), 1024; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051024 - 17 May 2024
Viewed by 496
Abstract
The expansion of renewable electricity storage technologies, including green hydrogen storage, is spurred by the need to address the high costs associated with hydrogen storage and the imperative to increase storage capacity. The initial section of the paper examines the intricacies of storing [...] Read more.
The expansion of renewable electricity storage technologies, including green hydrogen storage, is spurred by the need to address the high costs associated with hydrogen storage and the imperative to increase storage capacity. The initial section of the paper examines the intricacies of storing electricity generated from renewable sources, particularly during peak periods, through green hydrogen. Two primary challenges arise: firstly, the complexity inherent in the storage technology and its adaptation for electricity reproduction; and secondly, the cost implications throughout the technological chain, resulting in a significant increase in the price of the reproduced energy. Electric energy storage emerges as a pivotal solution to accommodate the growing proportion of renewable energy within contemporary energy systems, which were previously characterized by high stability. During the transition to renewable-based energy systems, optimizing energy storage technology to manage power fluctuations is crucial, considering both initial capital investment and ongoing operational expenses. The economic analysis primarily focuses on scenarios where electricity generated from renewable sources is integrated into existing power grids. The subsequent part of this paper explores the possibility of localizing excess electricity storage within a specific system, illustrated by domestic hot water. Full article
(This article belongs to the Section Energy Systems)
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15 pages, 7114 KiB  
Article
The Application of Rotary Twist Collecting Actuator Systems for Camellia oleifera Flower Bud Collection
by Qing Zhao, Lijun Li and Zhifeng Yang
Processes 2024, 12(5), 1023; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051023 - 17 May 2024
Viewed by 443
Abstract
Pollen transmission of Camellia oleifera is affected by climate and environment, and the quality of natural pollination is not high, which seriously affects the yield of Camellia oleifera. Artificial pollination is an effective way to solve the low fruit setting rate of [...] Read more.
Pollen transmission of Camellia oleifera is affected by climate and environment, and the quality of natural pollination is not high, which seriously affects the yield of Camellia oleifera. Artificial pollination is an effective way to solve the low fruit setting rate of natural pollination, but the problem to be solved urgently in artificial pollination is the collection of a large amount of pollen. At present, there is no mechanized equipment for Camellia oleifera flower bud collection, so developing an efficient pollen collection device has become a key problem that restricts the high-quality development of Camellia oleifera. In this paper, on the basis of measuring the tensile force, the shearing force, and the torsional moment required to remove Camellia Oleifera flower bud from the branch, which are 8.968 N, 13.94 N, and 0.0178 N·m, respectively, three types of Camellia oleifera flower bud collecting actuators were designed. According to the results of parameter design, feasibility analysis, and dynamic simulation, the power parameters of three types of Camellia oleifera flower bud collecting actuators were obtained. The experiment of collecting Camellia oleifera flower bud was designed, and the collection time, collection rate, and bud breakage rate of the three collecting actuators were compared. The experimental results show that the collection time of the rotary twist-type collecting actuator was 1.57 s, the collection rate was 91%, and the breakage rate was 4.9%, which can realize the efficient and low-loss collection of Camellia oleifera flowers bud, providing a theoretical basis for subsequent research on a Camellia oleifera flower bud collection robot. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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17 pages, 2722 KiB  
Article
Combustion Characteristics, Kinetics and Thermodynamics of Peanut Shell for Its Bioenergy Valorization
by Jialiu Lei, Xiaoyu Liu, Biao Xu, Zicong Liu and Yongjun Fu
Processes 2024, 12(5), 1022; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051022 - 17 May 2024
Viewed by 411
Abstract
To realize the utilization of peanut shell, this study investigates the combustion behavior, chemical kinetics and thermodynamic parameters of peanut shell using TGA under atmospheric air at the heating rates of 10, 20, and 30 K/min. Results indicate that increasing the heating rate [...] Read more.
To realize the utilization of peanut shell, this study investigates the combustion behavior, chemical kinetics and thermodynamic parameters of peanut shell using TGA under atmospheric air at the heating rates of 10, 20, and 30 K/min. Results indicate that increasing the heating rate leads to higher ignition, burnout, and peak temperatures, as observed in the TG/DTG curves shifting to the right. Analysis of combustion performance parameters suggest that higher heating rates can enhance combustion performances. Kinetic analysis using two model-free methods, KAS and FWO, shows that the activation energy (Eα) ranges from 93.30 to 109.65 kJ/mol for FWO and 89.72 to 103.88 kJ/mol for KAS. The data fit well with coefficient of determination values (R2) close to 1 and the mean squared error values (MSE) less than 0.006. Pre-exponential factors using FWO range from 2.19 × 106 to 8.08 × 107 s−1, and for KAS range from 9.72 × 105 to 2.25 × 107 s−1. Thermodynamic analysis indicates a low-energy barrier (≤±6 kJ/mol) between activation energy and enthalpy changes, suggesting easy reaction initiation. Furthermore, variations in enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) upon conversion (α) suggest that peanut shell combustion is endothermic and non-spontaneous, with the generation of more homogeneous or well-ordered products as combustion progresses. These findings offer a theoretical basis and data support for the further utilization of agricultural biomass. Full article
(This article belongs to the Topic Advances in Biomass Conversion)
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15 pages, 6342 KiB  
Article
High-Performance Porous pSi/Ag@C Anode for Lithium-Ion Batteries
by Kefan Li, Xiang Li, Liang Yuan, Zewen Han, Mengkui Li, Rui Ji, Yixin Zhan and Kai Tang
Processes 2024, 12(5), 1021; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051021 - 17 May 2024
Viewed by 465
Abstract
Silicon represents one of the most attractive anode materials in lithium-ion batteries (LIBs) due to its highest theoretical specific capacity. Thus, there is a most urgent need to prepare Si-based nano materials in a very efficient way and develop some reasonable approaches for [...] Read more.
Silicon represents one of the most attractive anode materials in lithium-ion batteries (LIBs) due to its highest theoretical specific capacity. Thus, there is a most urgent need to prepare Si-based nano materials in a very efficient way and develop some reasonable approaches for their modification in order to resolve the short-falls of Si anodes, which include both low conductivity and huge volume changes during intercalation of lithium ions. In this work, the kerf loss silicon (KL Si) from the photovoltaic industry has been used as an inexpensive Si source for the preparation of a porous silicon/silver/carbon composite (pSi/Ag@C) as an anode material. Porous silicon was embedded with Ag particles via the Ag-catalyzed chemical etching process, providing additional space to accommodate the large volume expansion of silicon. After carbon coating from polymerization of tannic acid on the surface of pSi/Ag, a high-speed conductive network over the surface of silicon was built and contributed to enhancing the electrochemical performance of the anode. The pSi/Ag@C electrode discharge capacity maintained at a stable value of 665.3 mAh g−1 after 100 cycles under 0.5 A g−1 and exhibited good rate performance. Therefore, this study recommends that the method is very promising for producing a silicon anode material for LIBs from KL Si. Full article
(This article belongs to the Section Materials Processes)
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18 pages, 1628 KiB  
Article
Comparative Study of the Stilbenes and Other Phenolic Compounds in Cabernet Sauvignon Wines Obtained from Two Different Vinifications: Traditional and Co-Inoculation
by Aleksandar Petrović, Nikolina Živković, Ljilja Torović, Ana Bukarica, Vladan Nikolić, Jelena Cvejić and Ljiljana Gojković-Bukarica
Processes 2024, 12(5), 1020; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051020 - 17 May 2024
Viewed by 597
Abstract
From grape cultivation to ripening and harvest timing to processing, each step of the winemaking process can be a critical point when it comes to wine quality and phenolic composition. In this study, the influence of winemaking technology on resveratrol and quercetin content, [...] Read more.
From grape cultivation to ripening and harvest timing to processing, each step of the winemaking process can be a critical point when it comes to wine quality and phenolic composition. In this study, the influence of winemaking technology on resveratrol and quercetin content, as well as other polyphenolic compounds, was investigated. Resveratrol is a non-flavonoid polyphenolic stilbene synthesized by grape skin when damaged by infectious diseases or ionizing radiation. Quercetin is a phenol found in grape skins and stems and is produced to protect grapes from UV light damage. Trans-resveratrol and quercetin are known to act as antioxidants, reduce the risk of atherosclerosis and type 2 diabetes, inhibit the growth of cancer cells, and prevent the release of allergic and inflammatory molecules. However, the question was whether red wine could be enriched with these phenols using a co-inoculation winemaking technology. The main new idea was to completely replace the cold maceration process with maceration with the addition of wild yeast (Torulaspora delbrueckii, Td). Maceration with the addition of wild yeast (Td) offers the following advantages over traditional cold maceration: (1) higher concentrations of trans-resveratrol (>35–40%) and quercetin (>35–40%) in the final wine, (2) the new wine has a higher potential for human health, (3) the wine has better aroma and stability due to the higher mannoprotein content, and (4) better energy efficiency in the production process. The study of stability during storage and aging also included derivatives of benzoic acid and hydroxycinnamic acid, piceid, catechin, naringenin, rutin, kaempherol, hesperetin, and anthocyanins. This study found that younger wines had higher phenolic content, while storage of the wine resulted in a decrease in total phenolic content, especially monomeric stilbenes and quercetin. This study represents a small part of the investigation of the influence of non-Saccharomyces yeasts on the phenolic profile of wine, which still requires extensive research with practical application. In addition, non-Saccharomyces yeasts such as Kluyveromyces thermotolerans, Candida stellata, and Metschnikowia pulcherrima could also be used in future studies. Full article
(This article belongs to the Special Issue Research and Optimization of Food Processing Technology)
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13 pages, 3982 KiB  
Article
Study on the Mechanism of Carbon Dioxide Miscible Fracturing Fluid Huff and Puff in Enhanced Oil Recovery
by Shijing Xu, Changquan Wang, Bin Gao and Tiezheng Wang
Processes 2024, 12(5), 1019; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051019 - 17 May 2024
Viewed by 446
Abstract
Carbon dioxide (CO2) miscible fracturing huff-and-puff technology now plays a pivotal role in enhancing crude oil recovery rates, particularly in reservoirs with challenging physical properties, strong water sensitivity, high injection pressure, and complex water-injection dynamics. In this study, the oil-increasing mechanism [...] Read more.
Carbon dioxide (CO2) miscible fracturing huff-and-puff technology now plays a pivotal role in enhancing crude oil recovery rates, particularly in reservoirs with challenging physical properties, strong water sensitivity, high injection pressure, and complex water-injection dynamics. In this study, the oil-increasing mechanism and huff-and-puff effect of CO2 miscible fracturing fluid are investigated through a comprehensive experimental approach. Specifically, experiments on PVT gas injection expansion, minimum miscible pressure, and CO2 miscible fracturing fluid huff and puff are conducted on the G fault block reservoir of the J Oilfield. The experimental findings demonstrate that injecting CO2 into reservoirs leads to an expansion in oil volume, a reduction in viscosity, and an increase in saturation pressure. Crude oil extraction is further enhanced by the addition of solubilizers and viscosity reducers. The use of solubilizers not only increases oil recovery rates but also reduces the minimum miscible pressure required for effective CO2 dispersion. We also found that shut-in times, permeability, and the huff-and-puff method used all have considerable impacts on huff-and-puff recovery rates. This study offers valuable technical insights, supporting the application of CO2 miscible fracturing huff-and-puff technology to enhance oil recovery rates in low-permeability reservoirs. Full article
(This article belongs to the Section Energy Systems)
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12 pages, 292 KiB  
Article
Fungal Isolation, Detection, and Quantification of Aflatoxins in Nuts Sold in the Lebanese Market
by Heba Hellany, Jean Claude Assaf, Joseph Matta and Mahmoud I. Khalil
Processes 2024, 12(5), 1018; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051018 - 17 May 2024
Viewed by 593
Abstract
This study examines the prevalence of aflatoxin contamination in 160 nut samples, both shelled and unshelled (including pistachios, peanuts, and walnuts), from the Lebanese market, focusing on their fungal contamination and specific toxigenic strains. Aflatoxin B1 (AFB1), known for its potent carcinogenic and [...] Read more.
This study examines the prevalence of aflatoxin contamination in 160 nut samples, both shelled and unshelled (including pistachios, peanuts, and walnuts), from the Lebanese market, focusing on their fungal contamination and specific toxigenic strains. Aflatoxin B1 (AFB1), known for its potent carcinogenic and immunosuppressive properties, was detected in various samples. Moisture content analysis showed that unshelled nuts often exceeded maximum moisture limits more frequently than shelled nuts, with levels ranging from 1.9 to 9.5%. The predominant fungal genus identified through cultivation on potato dextrose agar (PDA) plates was Aspergillus. In total, 55% of samples were contaminated with A. flavus and 45% with A. niger. All toxigenic strains isolated were identified as Aspergillus flavus. The aflatoxins, particularly AFB1, were quantified using the enzyme-linked immunosorbent assay (ELISA) and reversed-phase high-performance liquid chromatography (HPLC), revealing contamination in 43.8% of the samples, with concentrations ranging from 0.4 to 25 µg/kg. Some samples notably exceeded the established maximum tolerable limits (MTLs) for AFB1, set between 2 and 8 µg/kg. Shelled pistachios showed the highest contamination rate at 52% and were the most frequent to surpass the MTL of 8 µg/kg for pistachios, whereas walnuts displayed the lowest contamination levels, with only 15.4% exceeding the MTL for aflatoxins. Full article
(This article belongs to the Special Issue Food Safety Management and Quality Control Techniques)
13 pages, 1509 KiB  
Article
Development of New Series of Certified Reference Materials for Ferrosilicon Magnesium Alloys
by Justyna Kostrzewa, Jacek Anyszkiewicz, Tadeusz Gorewoda, Ewa Jamroz, Kjell Blandhol, Alf Yngve Guldhav, Magdalena Knapik, Jadwiga Charasińska and Agata Jakóbik-Kolon
Processes 2024, 12(5), 1017; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051017 - 17 May 2024
Viewed by 497
Abstract
This paper presents a practical approach to the production of certified reference materials (CRMs) for ferrosilicon magnesium alloys. These new CRMs are predicted to be used in fast X-ray fluorescence spectrometry (XRF) analysis, which does not require sample digestion and does not result [...] Read more.
This paper presents a practical approach to the production of certified reference materials (CRMs) for ferrosilicon magnesium alloys. These new CRMs are predicted to be used in fast X-ray fluorescence spectrometry (XRF) analysis, which does not require sample digestion and does not result in the production of acidic sewage and emissions, contrary to the classical and instrumental techniques currently used in laboratories. Four new certified reference materials (CRMs) were developed to fill the gap in the reference materials market and ensure fast and traceable analyses. The materials were produced with an industrial process and then homogenized and mixed to achieve the required compositions and level of homogeneity. The homogeneity was determined using specially developed analytical methods and confirmed statistically by ANOVA. Additionally, the results of the tests show the short- and long-term stabilities of the new materials. The certified values for specific element contents were determined in interlaboratory tests. All results were assessed statistically for outliers. The results from three or more independent and different analytical methods were used for the calculations. In parallel homogeneity, the stability, and characterization standard uncertainties were calculated and used in the estimation of the final expanded uncertainties of the certified values. Finally, four new CRMs were assisted with the proper certificates according to ISO standards. Full article
(This article belongs to the Section Materials Processes)
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18 pages, 19763 KiB  
Article
Thermal Stress Mechanism of Thermochemical Reactor of 5 kW Solar Simulator with Temperature Distribution as the Load Condition
by Xing Huang, Yan Lin, Xin Yao, Yang Liu, Fanglin Gao and Hao Zhang
Processes 2024, 12(5), 1016; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051016 - 16 May 2024
Viewed by 508
Abstract
In this paper, a solar thermochemical reactor is designed based on a 5 kW non-coaxial concentrating solar simulator, and a mathematical model is established for thermal calculations. The calculated temperature distribution is used as a load condition for thermal stress analyses. The model [...] Read more.
In this paper, a solar thermochemical reactor is designed based on a 5 kW non-coaxial concentrating solar simulator, and a mathematical model is established for thermal calculations. The calculated temperature distribution is used as a load condition for thermal stress analyses. The model is used to study the influence of the solar simulator power, solar reactor inner wall material’s emissivity, working pressure, gas inlet velocity, and thermocouple opening diameter on the thermal stress of the solar reactor. The results show that thermal stress increases with the increase in solar simulator power and the emissivity of the inner wall material in the solar reactor. The inlet velocity and working pressure have little effect on the thermal stress of the reactor and cannot prevent damage to the reactor. In the case of maintaining the diameter of the thermocouple at the front end of the reactor, increasing the diameter of the thermocouple inside the reactor leads to an increase in thermal stress around the reactor. Meanwhile, using a finer thermocouple can reduce the thermal stress inside the reactor and extend its service life, which will provide a foundation for designing practical industrial applications in the future. Full article
(This article belongs to the Section Energy Systems)
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18 pages, 4777 KiB  
Article
Plateau-Adapted Single-Pump, Single-Bed Vacuum Pressure Swing Adsorption Oxygen Generation Process Simulation and Optimization
by Yingying Zhang, Yanbin Li, Zhenxing Song, Hongyun Sun, Bolun Wen, Junming Su, Jun Ma and Yanjun Zhang
Processes 2024, 12(5), 1015; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051015 - 16 May 2024
Viewed by 509
Abstract
To enhance the oxygen guarantee capacity in high altitude areas and address the challenges of traditional pressure swing adsorption oxygen generation fixed equipment with large volume and multiple device modules, a novel single-reversible-pump single-bed vacuum pressure swing adsorption (VPSA) oxygen generation process was [...] Read more.
To enhance the oxygen guarantee capacity in high altitude areas and address the challenges of traditional pressure swing adsorption oxygen generation fixed equipment with large volume and multiple device modules, a novel single-reversible-pump single-bed vacuum pressure swing adsorption (VPSA) oxygen generation process was proposed and simulated. This study investigated the effects of purge on oxygen productivity, purity, recovery, and energy consumption, determining that the optimum ratio of total oxygen in the purge gas to the total oxygen in the feed gas (P/F) was 0.176. A set of principle prototypes was developed and validated in plains. The process performance was then simulated and studied at altitudes of 3000 m, 4000 m, and 5000 m. Finally, the optimization was carried out by adjusting the product flow rate and feed flow rate, revealing that the best performance can be achieved when the oxygen purity exceeded 90% with lower energy consumption or larger productivity than the optimization goal. This study serves as a valuable reference for the optimization of the VPSA oxygen generation process in a plateau environment. Full article
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17 pages, 5657 KiB  
Article
Performance Improvement of an Electric Vehicle Charging Station Using Brain Emotional Learning-Based Intelligent Control
by Sherif A. Zaid, Hani Albalawi, Aadel M. Alatwi and Atef Elemary
Processes 2024, 12(5), 1014; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051014 - 16 May 2024
Viewed by 492
Abstract
Electric vehicle (EV) charging facilities are essential to their development and deployment. These days, autonomous microgrids that use renewable energy resources to energize charging stations for electric vehicles alleviate pressure on the public electricity grid. Nevertheless, controlling and managing such charging stations’ energy [...] Read more.
Electric vehicle (EV) charging facilities are essential to their development and deployment. These days, autonomous microgrids that use renewable energy resources to energize charging stations for electric vehicles alleviate pressure on the public electricity grid. Nevertheless, controlling and managing such charging stations’ energy is difficult due to the nonlinearity and irregular character of renewable energy sources. The current research recommends using a Brain Emotional Learning Intelligent Control (BELBIC) controller to enhance an autonomous EV charging station’s performance and power management. The charging station uses a battery to store energy and is primarily powered by photovoltaic (PV) solar energy. The principles of BELBIC are dependent on emotional cues and sensory inputs, and they are based on an emotion processing system in the brain. Noise and parameter variations do not affect this kind of controller. In this study, the performance of a conventional proportional–integral (PI) controller and the suggested BELBIC controller is evaluated for variations in solar insolation. The various parts of an EV charging station are simulated and modelled by the MATLAB/Simulink framework. The findings show that, in comparison to the conventional PI controller, the suggested BELBIC controller greatly enhances the transient responsiveness of the EV charging station’s performance. The EV keeps charging while the storage battery perfectly saves and keeps steady variations in PV power, even in the face of any PV insolation disturbances. The suggested system’s simulation results are provided and scrutinized to confirm the concept’s suitability. The findings validate the robustness of the suggested BELBIC control versus parameter variations. Full article
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20 pages, 9150 KiB  
Article
Propagation Mechanism and Suppression Strategy of DC Faults in AC/DC Hybrid Microgrid
by Chun Xiao, Yulu Ren, Qiong Cao, Ruifen Cheng and Lei Wang
Processes 2024, 12(5), 1013; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051013 - 16 May 2024
Viewed by 386
Abstract
Due to their efficient renewable energy consumption performance, AC/DC hybrid microgrids have become an important development form for future power grids. However, the fault response will be more complex due to the interconnected structure of AC/DC hybrid microgrids, which may have a serious [...] Read more.
Due to their efficient renewable energy consumption performance, AC/DC hybrid microgrids have become an important development form for future power grids. However, the fault response will be more complex due to the interconnected structure of AC/DC hybrid microgrids, which may have a serious influence on the safe operation of the system. Based on an AC/DC hybrid microgrid with an integrated bidirectional power converter, research on the interaction impact of faults was carried out with the purpose of enhancing the safe operation capability of the microgrid. The typical fault types of the DC sub-grid were selected to analyze the transient processes of fault circuits. Then, AC current expressions under the consideration of system interconnection structure were derived and, on this basis, we obtained the response results of non-fault subnets under the fault process, in order to reveal the mechanism of DC fault propagation. Subsequently, a current limitation control strategy based on virtual impedance control is proposed to address the rapid increase in the DC fault current. On the basis of constant DC voltage control in AC/DC hybrid microgrids, a virtual impedance control link was added. The proposed control strategy only needs to activate the control based on the change rate of the DC current, without additional fault detection systems. During normal operations, virtual impedance has a relatively small impact on the steady-state characteristics of the system. In the case of a fault, the virtual impedance resistance value is automatically adjusted to limit the change rate and amplitude of the fault current. Finally, a DC fault model of the AC/DC hybrid microgrid was built on the RTDS platform. The simulation and experimental results show that the control strategy proposed in this paper can reduce the instantaneous change rate of the fault state current from 19.1 kA/s to 2.73 kA/s, and the error between the calculated results of equivalent modeling and simulation results was within 5%. The obtained results verify the accuracy of the mathematical equivalent model and the effectiveness of the proposed current limitation control strategy. Full article
(This article belongs to the Section Energy Systems)
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13 pages, 5541 KiB  
Article
Solid–Liquid Two-Phase Flowmeter Flow-Passage Wall Erosion Evolution Characteristics and Calibration of Measurement Accuracy
by Wei Han, Lumin Yan, Rennian Li, Jing Zhang, Xiang Yang, Lei Ji and Yan Qiang
Processes 2024, 12(5), 1012; https://0-doi-org.brum.beds.ac.uk/10.3390/pr12051012 - 16 May 2024
Viewed by 499
Abstract
Solid–liquid two-phase flowmeters are widely used in critical sectors, such as petrochemicals, energy, manufacturing, the environment, and various other fields. They are indispensable devices for measuring flow. Currently, research has primarily focused on gas–liquid two-phase flow within the flowmeter, giving limited attention to [...] Read more.
Solid–liquid two-phase flowmeters are widely used in critical sectors, such as petrochemicals, energy, manufacturing, the environment, and various other fields. They are indispensable devices for measuring flow. Currently, research has primarily focused on gas–liquid two-phase flow within the flowmeter, giving limited attention to the impact of solid phases. In practical applications, crude oil frequently contains solid particles and other impurities, leading to equipment deformation and a subsequent reduction in measuring accuracy. This paper investigates how particle dynamic parameters affect the erosion evolution characteristics of flowmeters operating in solid–liquid two-phase conditions, employing the dynamic boundary erosion prediction method. The results indicate that the erosion range and peak erosion position on the overcurrent wall of the solid–liquid two-phase flowmeter vary with different particle dynamic parameters. Erosion mainly occurs at the contraction section of the solid–liquid two-phase flowmeter. When the particle inflow velocity increases, the erosion range shows no significant change, but the peak erosion position shifts to the right, primarily due to the evolution of the erosion process. With an increase in particle diameter, the erosion range expands along the inlet direction due to turbulent diffusion, as particles with lower kinetic energy exhibit better followability. There is no significant change in the erosion range and peak erosion position with an increase in particle volume fraction and particle sphericity. With a particle inflow velocity of 8.4 m/s, the maximum erosion depth reaches 750 μm. In contrast, at a particle sphericity of 0.58, the minimum erosion depth is 251 μm. Furthermore, a particle volume fraction of 0.5 results in a maximum flow coefficient increase of 1.99 × 10−3. Full article
(This article belongs to the Special Issue New Research on Oil and Gas Equipment and Technology)
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