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Processes, Volume 12, Issue 6 (June 2024) – 217 articles

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15 pages, 5303 KiB  
Article
Image Analysis Techniques Applied in the Drilling of a Carbon Fibre Reinforced Polymer and Aluminium Multi-Material to Assess the Delamination Damage
by Rúben Daniel Fernandes de Sousa Costa, Marta Luísa Sousa Barbosa, Filipe Gonçalo Andrade da Silva, Tiago Emanuel Fraga Silva, Abílio Manuel Pinho de Jesus, Francisco José Gomes da Silva, Luís Miguel Pereira Durão and João Manuel R. S. Tavares
Processes 2024, 12(6), 1258; https://doi.org/10.3390/pr12061258 (registering DOI) - 19 Jun 2024
Abstract
Due to the high abrasiveness and anisotropic nature of composites, along with the need to machine different materials at the same time, drilling multi-materials is a difficult task, and usually results in material damage, such as uncut fibres and delamination, hindering hole functionality [...] Read more.
Due to the high abrasiveness and anisotropic nature of composites, along with the need to machine different materials at the same time, drilling multi-materials is a difficult task, and usually results in material damage, such as uncut fibres and delamination, hindering hole functionality and reliability. Image processing and analysis algorithms can be developed to effectively assess such damage, allowing for the calculation of delamination factors essential to the quality control of hole inspection in composite materials. In this study, a digital image processing and analysis algorithm was developed in Python to perform the delamination evaluation of drilled holes on a carbon fibre reinforced polymer (CFRP) and aluminium (Al) multi-material. This algorithm was designed to overcome several limitations often found in other algorithms developed with similar purposes, which frequently lead to user mistakes and incorrect results. The new algorithm is easy to use and, without requiring manual pre-editing of the input images, is fully automatic, provides more complete and reliable results (such as the delamination factor), and is a free-of-charge software. For example, the delamination factors of two drilled holes were calculated using the new algorithm and one previously developed in Matlab. Using the previous Matlab algorithm, the delamination factors of the two holes were 1.380 and 2.563, respectively, and using the new Python algorithm, the results were equal to 3.957 and 3.383, respectively. The Python results were more trustworthy, as the first hole had a higher delamination area, so its factor should be higher than that of the second one. Full article
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21 pages, 2072 KiB  
Article
Study on Activation and Restructuring of Key Strata in Shallowly Buried Coal Seam Bearing Structure and Load Characteristics
by Yifeng He, Jie Zhang, Hui Liu, Tao Yang and Jianping Sun
Processes 2024, 12(6), 1257; https://doi.org/10.3390/pr12061257 (registering DOI) - 18 Jun 2024
Abstract
The mining of shallow coal seam groups triggers the activation of overlying strata, leading to increased pressure and support difficulties, thereby posing a threat to the safe extraction of underlying coal seams. Against the backdrop of Longhua Coal Mine, this study utilized physical [...] Read more.
The mining of shallow coal seam groups triggers the activation of overlying strata, leading to increased pressure and support difficulties, thereby posing a threat to the safe extraction of underlying coal seams. Against the backdrop of Longhua Coal Mine, this study utilized physical similarity simulation experiments to obtain the activated, restructured load-bearing structure and the migration characteristics of overlying strata. Theoretical calculations were employed to establish both a rolling friction mechanics model for the activated load-bearing structure and a mechanical model for the combined load-bearing structure of key strata. The research indicates that during the initial activation phase, the load-bearing structure exhibits a V-shaped hinged arch, with directly collapsed rock masses transitioning towards spherical shapes, resulting in the sub-key strata shifting from sliding friction to rolling friction. Based on the rolling friction mechanics model of the activated load-bearing structure, we derived the rolling friction coefficient of key blocks in the sub-key strata and the instability criterion of the load-bearing structure under rolling friction conditions. Considering the migration characteristics of the activated restructured load-bearing structure, four types of combined load-bearing structures were identified, and the load calculation formulas in the mechanical model were derived, with the rationality of these formulas verified through case analysis. Full article
(This article belongs to the Section Energy Systems)
28 pages, 836 KiB  
Review
Advancing Wastewater Treatment: A Comparative Study of Photocatalysis, Sonophotolysis, and Sonophotocatalysis for Organics Removal
by Szabolcs Bognár, Dušica Jovanović, Vesna Despotović, Nina Finčur, Predrag Putnik and Daniela Šojić Merkulov
Processes 2024, 12(6), 1256; https://doi.org/10.3390/pr12061256 (registering DOI) - 18 Jun 2024
Viewed by 62
Abstract
Clear and sanitarily adequate water scarcity is one of the greatest problems of modern society. Continuous population growth, rising organics concentrations, and common non-efficient wastewater treatment technologies add to the seriousness of this issue. The employment of various advanced oxidation processes (AOPs) in [...] Read more.
Clear and sanitarily adequate water scarcity is one of the greatest problems of modern society. Continuous population growth, rising organics concentrations, and common non-efficient wastewater treatment technologies add to the seriousness of this issue. The employment of various advanced oxidation processes (AOPs) in water treatment is becoming more widespread. In this review, the state-of-the-art application of three AOPs is discussed in detail: photocatalysis, sonophotolysis, and sonophotocatalysis. Photocatalysis utilizes semiconductor photocatalysts to degrade organic pollutants under light irradiation. Sonophotolysis combines ultrasound and photolysis to generate reactive radicals, enhancing the degradation of organic pollutants. Sonophotocatalysis synergistically combines ultrasound with photocatalysis, resulting in improved degradation efficiency compared to individual processes. By studying this paper, readers will get an insight into the latest published data regarding the above-mentioned processes from the last 10 years. Different factors are compared and discussed, such as degradation efficiency, reaction kinetics, catalyst type, ultrasound frequency, or water matrix effects on process performance. In addition, the economic aspects of sonophotolysis, photocatalysis, and sonophotocatalysis will be also analyzed and compared to other processes. Also, the future research directions and potential applications of these AOPs in wastewater treatment will be highlighted. This review offers invaluable insights into the selection and optimization of AOPs. Full article
(This article belongs to the Special Issue 2nd Edition of Innovation in Chemical Plant Design)
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15 pages, 1978 KiB  
Article
Hydrophobic Deep Eutectic Solvents for Ethanol, Propan-1-ol, and Propan-2-ol Recovery from Aqueous Solutions
by Dalal J. S. A. Audeh, Adriano Carniel, Cristiano Piacsek Borges, Maria Alice Zarur Coelho, Filipe Smith Buarque and Bernardo Dias Ribeiro
Processes 2024, 12(6), 1255; https://doi.org/10.3390/pr12061255 (registering DOI) - 18 Jun 2024
Abstract
Separating hydroalcoholic mixtures remains a significant challenge in engineering. Liquid–liquid extraction has emerged as an appealing alternative method, because it avoids the need for the large energy inputs, volatile organic compounds, and high pressures that are typically required by other separation processes. This [...] Read more.
Separating hydroalcoholic mixtures remains a significant challenge in engineering. Liquid–liquid extraction has emerged as an appealing alternative method, because it avoids the need for the large energy inputs, volatile organic compounds, and high pressures that are typically required by other separation processes. This study explores the use of hydrophobic deep eutectic solvents (HDESs) composed of terpenes and 10-undecenoic acid as extraction agents for the liquid–liquid separation of hydroalcoholic mixtures composed of alcohols (ethanol, propan-1-ol, and propan-2-ol) and water. The water content in the solvents studied was notably low, reflecting their hydrophobic nature. For the dried HDES samples, the water content ranged from 553 to 4901 ppm. In contrast, the water-saturated samples exhibited higher water contents, ranging from 7250 to 20,864 ppm. The HDES based on thymol, DL-menthol, and L-menthol displayed a eutectic point at an xterpenes of approximately 0.67. These mixtures maintained a liquid state up to a mole fraction of terpenes around 0.75. In contrast, the HDES composed of carvacrol, fenchyl alcohol, and α-terpineol exhibited their eutectic point at an xterpenes near 0.5. Notably, these mixtures remained in a liquid state across the entire composition range studied. The 2:1 molar ratio (HBA:HBD) presented the best values for extracting alcohols, reaching 34.04%, 36.59%, and 39.78% for ethanol, propan-2-ol, and propan-1-ol, respectively. These results show that HDES can be applied to overcome issues with existing extraction solvents, increasing the separation efficiency and making the process eco-friendly. Full article
(This article belongs to the Special Issue Green Separation and Purification Processes)
23 pages, 9966 KiB  
Article
Rapid Classification and Diagnosis of Gas Wells Driven by Production Data
by Zhiyong Zhu, Guoqing Han, Xingyuan Liang, Shuping Chang, Boke Yang and Dingding Yang
Processes 2024, 12(6), 1254; https://doi.org/10.3390/pr12061254 (registering DOI) - 18 Jun 2024
Viewed by 93
Abstract
Conventional gas well classification methods cannot provide effective support for gas well routine management, and suffer from poor timeliness. In order to guide the on-site operation in liquid loading gas wells and improve the timeliness of gas well classification, this paper proposes a [...] Read more.
Conventional gas well classification methods cannot provide effective support for gas well routine management, and suffer from poor timeliness. In order to guide the on-site operation in liquid loading gas wells and improve the timeliness of gas well classification, this paper proposes a production data-driven gas well classification method based on the LDA-DA (Linear Discriminant Analysis–Discriminant Analysis) combination model. In this method, considering the requirements of routine management, gas wells are evaluated from two aspects: liquid drainage capacity (LDC) and liquid production intensity (LPI), and are classified into six types. Domain knowledge is used to perform the feature engineering on the on-site production data, and five features are set up to quantitatively evaluate the gas well and to create classification samples. On this basis, in order to specify the optimal data processing flow to establish the gas well classification map, four linear dimensionality reduction techniques, LDA, PCA, LPP, and ICA, are used to reduce the dimensionality of original classification samples, and then, four classical classification algorithms, NB, DA, KNN, and SVM, are trained and evaluated on the low-dimensional samples, respectively. The results show that the LDA space achieves the optimal sample separation and is chosen as the decision space for gas well classification. The DA algorithm obtains the top performance, i.e., the highest Average Macro F1-score of 95.619%, in the chosen decision space, and is employed to determine the classification boundaries in the decision space. At this point, the LDA-DA combination model for sample data processing is developed. Based on this model, gas well classification maps can be established by data mining, and the rapid evaluation and diagnosis of gas wells can be achieved. This method realizes instant and efficient production data-driven gas well classification, and can provide timely decision-making support for gas well routine management. It introduces new ideas for performing gas well classification, expanding the content and scope of the classification work, and presenting valuable insights for further research in this field. Full article
(This article belongs to the Section Energy Systems)
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18 pages, 14278 KiB  
Article
Research on Thread Seal Failure Mechanism of Casing Hanger in Shale Gas Wells and Prevention Measures
by Yisheng Mou, Yonggang Xie, Fengqi Wei, Han Zhao and Lihong Han
Processes 2024, 12(6), 1253; https://doi.org/10.3390/pr12061253 (registering DOI) - 18 Jun 2024
Viewed by 88
Abstract
The strength and sealing failure of the connecting thread of the casing head mandrel hanger causes huge economic losses. One of the major challenges is the thread seal failure mechanism of the casing hanger in the wellhead during pressure testing in shale gas [...] Read more.
The strength and sealing failure of the connecting thread of the casing head mandrel hanger causes huge economic losses. One of the major challenges is the thread seal failure mechanism of the casing hanger in the wellhead during pressure testing in shale gas wells. In order to analyze the failure causes of connecting threads and put forward improvement measures, a typical case of a well accompanied by a hanger seal failure is analyzed in this paper, and a series of material tests are carried out. The microstructure and mechanical properties of casing materials and hanger materials could meet the field requirements. It is concluded that both the hanger material and casing material are characterized with significant ductile fracture. A three-dimensional model of the hanger and casing system is established, and the mechanical behavior is calculated for the connecting thread under different working conditions. The results showed that the connection degree of the hanger–casing is insufficient at the torque recommended by the manufacturer because of the difference in wall thickness between the box thread of the hanger and the box thread of the joint according to the connection degree of the coupling casing. It is seen that the high contact pressure ring of zone three on the sealing surface plays an effective sealing role under the manufacturer’s recommended torque (20,465 N·m). Finally, when the torque is increased by 25%, the maximum contact pressure between the pin thread of the casing and the box thread of the hanger can fully meet the internal pressure from the wellbore pressure test and the internal pressure strength required for subsequent operations. Full article
(This article belongs to the Special Issue Risk Assessment and Reliability Engineering of Process Operations)
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14 pages, 1652 KiB  
Article
Demand Management for Manufacturing Loads Considering Temperature Control under Dynamic Electricity Prices
by Yan Yang, Junhui Yu and Hengrui Ma
Processes 2024, 12(6), 1252; https://doi.org/10.3390/pr12061252 (registering DOI) - 18 Jun 2024
Viewed by 83
Abstract
Demand response (DR) can provide extra scheduling flexibility for power systems. Different from industrial and residential loads, the production process of manufacturing loads includes multiple production links, and complex material flow and energy flow are closely coupled, which can be seen as a [...] Read more.
Demand response (DR) can provide extra scheduling flexibility for power systems. Different from industrial and residential loads, the production process of manufacturing loads includes multiple production links, and complex material flow and energy flow are closely coupled, which can be seen as a typical nondeterministic polynomial-time (NP) hard problem. In addition, there is a coupling effect between the temperature-controlled loads (TCLs) and the manufacturing loads, which has often been ignored in previous research, resulting in conservative electricity consumption planning. This paper proposes an optimal demand management for the manufacturing industry. Firstly, the power consumption characteristics of manufacturing loads are analyzed in detail. A state task network (STN) is introduced to decouple the relationship between energy and material flow in each production link. Combining STN and production equipment parameters, a general MILP model is constructed to describe the whole production process of the manufacturing industry. Then, a mathematical model of the TCLs considering a comfortable human degree is established. Fully considering the electricity consumption behavior of equipment and TCLs, the model predictive control (MPC) method is adopted to generate the optimal scheduling plan. Finally, an actual seat production enterprise is used to verify the feasibility and effectiveness of the proposed demand management strategy. Full article
(This article belongs to the Section Energy Systems)
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21 pages, 3509 KiB  
Article
An Efficient Real-Time Vehicle Classification from a Complex Image Dataset Using eXtreme Gradient Boosting and the Multi-Objective Genetic Algorithm
by Pemila Mani, Pongiannan Rakkiya Goundar Komarasamy, Narayanamoorthi Rajamanickam, Roobaea Alroobaea, Majed Alsafyani and Abdulkareem Afandi
Processes 2024, 12(6), 1251; https://doi.org/10.3390/pr12061251 (registering DOI) - 18 Jun 2024
Viewed by 95
Abstract
Recent advancements in image processing and machine-learning technologies have significantly improved vehicle monitoring and identification in road transportation systems. Vehicle classification (VC) is essential for effective monitoring and identification within large datasets. Detecting and classifying vehicles from surveillance videos into various categories is [...] Read more.
Recent advancements in image processing and machine-learning technologies have significantly improved vehicle monitoring and identification in road transportation systems. Vehicle classification (VC) is essential for effective monitoring and identification within large datasets. Detecting and classifying vehicles from surveillance videos into various categories is a complex challenge in current information acquisition and self-processing technology. In this paper, we implement a dual-phase procedure for vehicle selection by merging eXtreme Gradient Boosting (XGBoost) and the Multi-Objective Optimization Genetic Algorithm (Mob-GA) for VC in vehicle image datasets. In the initial phase, vehicle images are aligned using XGBoost to effectively eliminate insignificant images. In the final phase, the hybrid form of XGBoost and Mob-GA provides optimal vehicle classification with a pioneering attribute-selection technique applied by a prominent classifier on 10 publicly accessible vehicle datasets. Extensive experiments on publicly available large vehicle datasets have been conducted to demonstrate and compare the proposed approach. The experimental analysis was carried out using a myRIO FPGA board and HUSKY Lens for real-time measurements, achieving a faster execution time of 0.16 ns. The investigation results show that this hybrid algorithm offers improved evaluation measures compared to using XGBoost and Mob-GA individually for vehicle classification. Full article
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9 pages, 2682 KiB  
Article
Practice of Improving Saline–Alkali Soil with Bio-Humic Acid
by Chuyan Zhang, Yingyun Qiao and Qiang Song
Processes 2024, 12(6), 1250; https://doi.org/10.3390/pr12061250 (registering DOI) - 18 Jun 2024
Viewed by 100
Abstract
The improvement and exploitation of saline–alkali soil is a hot topic worldwide. Analysis of soil aggregate structure and water and of the salt transport law, a new technology that uses humic acid as a saline–alkali soil amendment has been proposed. These advancements may [...] Read more.
The improvement and exploitation of saline–alkali soil is a hot topic worldwide. Analysis of soil aggregate structure and water and of the salt transport law, a new technology that uses humic acid as a saline–alkali soil amendment has been proposed. These advancements may effectively improve the soil aggregate structure of saline–alkali soil at the source. In this study, biological pyrolysis liquid was modified to produce soil modifier for saline–alkali land, and this soil modifier was used in a rice planting experiment. The results show that the application of a bio-humic acid soil amendment in the amount of 3000 kg/ha and its combination with humic acid fertilizer produced rice yields as high as 9750 kg/ha. At the same time, the pH of the soil was reduced from 10.81 to 8.95 (with bio-humic acid soil amendment content of 3000 kg/ha), and the soil organic matter demonstrated a trend of increasing with an increased amount of bio-humic acid soil amendment. The content of calcium, magnesium, and trace elements in the soil were clearly increased with the use of the amended soil in comparison with the normal group. With this amendment, saline–alkali land could be transformed and planted in the same year, increasing the potential yearly income for the land. This may be efficient and environmentally friendly, encouraging the agricultural circular economy. Full article
(This article belongs to the Section Environmental and Green Processes)
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15 pages, 1224 KiB  
Article
Evaluation and Simulation of the Adsorption Capacity of Octocrylene Sunscreen on Commercial Carbon and Biochar from Spent Coffee Beans
by Sandra Andreola Franco da Rocha, Bianca Caroline da Silva Rocha, Luiz Eduardo Zani de Moraes, João Marcos Pires Villaça, Diane Scapin, Diego Espirito Santo, Regiane da Silva Gonzalez, Osvaldo Valarini Junior and Ana Paula Peron
Processes 2024, 12(6), 1249; https://doi.org/10.3390/pr12061249 (registering DOI) - 18 Jun 2024
Viewed by 126
Abstract
The emerging pollutant octocrylene is not efficiently removed from effluents by conventional treatment and is recurrently found in rivers. This study evaluated the adsorption of octocrylene using commercial carbon and biochar from spent coffee grounds activated with ZnCl2. The two adsorbents [...] Read more.
The emerging pollutant octocrylene is not efficiently removed from effluents by conventional treatment and is recurrently found in rivers. This study evaluated the adsorption of octocrylene using commercial carbon and biochar from spent coffee grounds activated with ZnCl2. The two adsorbents had an efficiency of approximately 100% in pollutant removal throughout the experimental design. The kinetics and equilibrium isotherms showed a good correlation with the experimental data. The kinetics showed adsorption of the contaminant in 40 min for both adsorbents. The model equilibrium isotherms with the best fit and adsorption capacity was Langmuir for biochar, with a capacity of 37.822 ± 0.005 µg∙mg−1 compared to 33.602 ± 0.202 µg∙mg−1 for commercial carbon. Furthermore, a toxicity analysis of a 600 µg∙L−1 octocrylene solution was carried out before and after adsorption with the two charcoals separately, using Allium cepa roots. Before adsorption, the solution was phytotoxic and cytogenotoxic. After adsorption, the solution obtained for each charcoal no longer caused toxicity to the roots. The charcoals tested had high removal efficiency and adsorption capacity, a condition reiterated by the toxicity results. However, biochar better represented the Langmuir model in the adsorption process when removing octocrylene from the aqueous medium. Full article
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18 pages, 7698 KiB  
Article
Bird Droppings Defects Detection in Photovoltaic Modules Based on CA-YOLOv5
by Linjun Liu, Qiong Li, Xu Liao and Wenbao Wu
Processes 2024, 12(6), 1248; https://doi.org/10.3390/pr12061248 (registering DOI) - 18 Jun 2024
Viewed by 115
Abstract
Due to the characteristics of different forms and small bird droppings-related defects in photovoltaic modules, problems of missing detection, wrong detection, and low detection accuracy often exist in the bird droppings covering the detection of photovoltaic modules. In this paper, a defect identification [...] Read more.
Due to the characteristics of different forms and small bird droppings-related defects in photovoltaic modules, problems of missing detection, wrong detection, and low detection accuracy often exist in the bird droppings covering the detection of photovoltaic modules. In this paper, a defect identification method based on the improved Coordinate Attention—You Only Look Once (CA-YOLOv5) network is proposed. Firstly, a layer of the Coordinate Attention module is added between the Backbone and Neck network, which takes into account channel and location information to enhance the feature extraction ability of the network model. Secondly, the small target detection layer is added to fuse different feature information from shallow networks and deep networks so as to improve the multi-scale feature detection ability of the network structure and effectively improve the detection effect of small targets. Finally, the experimental results show that, compared with the original algorithm, the proposed improved algorithm based on YOLOv5s has a mean average precision (mAP) value of 92%, an increase of 5.2%, and the model volume is also reduced in different degrees compared with other mainstream algorithms, achieving a good balance between detection accuracy and model volume. The results show that the model has a more accurate detection result for the bird droppings-related defect detection of photovoltaic modules and can provide a reference for the detection of photovoltaic modules in real life. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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14 pages, 2965 KiB  
Article
Study on the Inner Mechanisms of Gas Transport in Matrix for Shale Gas Recovery with In Situ Heating Technology
by Zhongkang Li, Zantong Hu, Ying Li, Xiaojun Wu, Junqiang Tian and Wenjing Zhou
Processes 2024, 12(6), 1247; https://doi.org/10.3390/pr12061247 - 18 Jun 2024
Viewed by 201
Abstract
In order to improve the productivity of shale gas, in situ heating technology has been applied generally. However, this technology is limited by unknown properties in heated matrix, e.g., permeability. Therefore, a method for measuring the permeability of heated shale matrix particles was [...] Read more.
In order to improve the productivity of shale gas, in situ heating technology has been applied generally. However, this technology is limited by unknown properties in heated matrix, e.g., permeability. Therefore, a method for measuring the permeability of heated shale matrix particles was designed, and transport tests were conducted on the shale matrix at heating temperatures of 100~600 degrees centigrade. Through fitting the experimental data with numerical simulation results, pore structures and permeabilities at different heating temperature conditions were obtained and the corresponding transport properties were determined. The porosity and pore radius were positively correlated with the heating temperature, while the tortuosity was negatively correlated with the temperature of the heat treatment. Despite the weakening effect of Knudsen diffusion transport, slippage transport played a critical role in the transport function of the heated shale matrix, and the domination became stronger at higher heating temperatures. The study of gas transport in heated shale matrix provides a guarantee for the effective combination of in situ heating technology. Full article
(This article belongs to the Section Energy Systems)
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15 pages, 1698 KiB  
Article
Flow Properties of Coarse Powders Used in Food Extrusion as a Function of Moisture Content
by Cameron McGuire, Kaliramesh Siliveru, Snehasis Chakraborty, Kingsly Ambrose and Sajid Alavi
Processes 2024, 12(6), 1246; https://doi.org/10.3390/pr12061246 - 18 Jun 2024
Viewed by 206
Abstract
The extrusion processing of food powder relies heavily on its moisture content to aid in flow and proper cooking, shaping, and/or puffing. This study focused on the impact of the moisture content on the dynamic flow and shear properties of coarse food powders [...] Read more.
The extrusion processing of food powder relies heavily on its moisture content to aid in flow and proper cooking, shaping, and/or puffing. This study focused on the impact of the moisture content on the dynamic flow and shear properties of coarse food powders (corn meal, wheat farina, and granulated sugar). The dynamic flow properties explored were the specific basic flowability energy (SBFE), specific energy, stability index, and flow rate index. The shear properties were the angle of internal friction, unconfined yield strength, major principal stress, wall friction angle, flow factor (FF), and compressibility. Corn meal exhibited an increase in SBFE as the moisture content increased (6.70 mJ/g at 13.13% to 9.14 mJ/g at 19.61%) but no change in FF (4.94 to 5.11); wheat farina also showed an increase in energy requirement as the moisture increased (5.81 mJ/g at 13.73% to 9.47 mJ/g 19.57%) but a marked decrease in FF ratings (18.47 to 6.1); granulated sugar showed a decrease in energy requirements as the moisture increased (51.73 mJ/g at 0.06% moisture content to 13.58 mJ/g at 0.78% moisture content) and a decrease in FF ratings (8.53 to 3.47). Overall, upon the addition of moisture, corn meal became cohesive yet free-flowing; wheat farina became less compressible and more cohesive; and granulated sugar became more cohesive and compressible and less free-flowing. Full article
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10 pages, 1434 KiB  
Article
Properties of Binderless Insulating Boards Made from Canary Island Date Palm and Cork Particles
by Berta Elena Ferrandez-Garcia, Teresa Garcia-Ortuño, Manuel Ferrandez-Villena and Maria Teresa Ferrandez-Garcia
Processes 2024, 12(6), 1245; https://doi.org/10.3390/pr12061245 - 18 Jun 2024
Viewed by 229
Abstract
Agglomerated cork is a natural cork that has gone through a process of crushing and pressing using heat and binders. One of its applications is thermal insulator in construction. The design of these materials is becoming an essential part of building. The raw [...] Read more.
Agglomerated cork is a natural cork that has gone through a process of crushing and pressing using heat and binders. One of its applications is thermal insulator in construction. The design of these materials is becoming an essential part of building. The raw materials currently used to make insulators consume a large amount of energy, which has created the need to increase the use of renewable and ecological resources such as plant fibers to reduce the environmental problems generated. The objective of this study was to determine the different properties of experimental particleboard panels made from cork and Canary Island date palms without using any binder at minimum energy consumption. The produced cork–palm boards (density of 850 kg/m3, reached a MOR 8.83 N/mm2, MOE 794.5 N/mm2, and IB 0.38 N/mm2) are higher values than the traditional cork particleboards with UF made from cork. The thermal conductivity values obtained 0.069 to 0.096 W/m·K are higher than cork boards with UF. Ecological boards that can be used as rigid thermal insulators in the construction industry have been achieved to improve the mechanical properties of the traditional agglomerated cork. Full article
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16 pages, 1938 KiB  
Article
Electrochemical Characteristics of Microbial Fuel Cells Operating with Various Food Industry Wastewaters
by Georgios Bampos, Zoe Gargala, Ilias Apostolopoulos and Georgia Antonopoulou
Processes 2024, 12(6), 1244; https://doi.org/10.3390/pr12061244 - 18 Jun 2024
Viewed by 219
Abstract
In the present work, four different wastewaters from the food industry were used in parallel, in four identical dual-chamber MFCs, with graphite granules as anodic electrodes. Specifically, a mixture of hydrogenogenic reactor effluents (effluents from a dark fermentation reactor fed with cheese whey [...] Read more.
In the present work, four different wastewaters from the food industry were used in parallel, in four identical dual-chamber MFCs, with graphite granules as anodic electrodes. Specifically, a mixture of hydrogenogenic reactor effluents (effluents from a dark fermentation reactor fed with cheese whey (CW), for hydrogen production), CW, and a mixture of expired fruit juices and wastewater from the confectionery industry were simultaneously used in MFCs to evaluate the effect of the type of effluent/wastewater on their efficiency. An electrochemical characterization was performed using electrochemical impedance spectroscopy measurements under open- (OCP) and closed-circuit conditions, at the beginning and end of the operating cycle, and the internal resistances were determined and compared. The results showed that the highest OCP value, as well as the highest power density (Pmax) and Coulombic efficiency (εcb) at the beginning of the operating cycle, was exhibited by the MFC, using a sugar-rich wastewater from the confectionery industry as substrate (sugar accounts for almost 92% of the organic content). This can be correlated with the low internal resistance extracted from the Nyquist plot at OCP. In contrast, the use of CW resulted in a lower performance in terms of OCP, εcb and Pmax, which could be correlated to the high internal resistance and the composition of CW, a substrate rich in lactose (disaccharide), and which also contains other substances (sugars account for almost 72% of its organic content, while the remaining 28% is made up of other soluble compounds). Full article
(This article belongs to the Special Issue Evaluation and Optimization of Fuel Cell Performance)
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15 pages, 1014 KiB  
Article
Application of Multi-Dimensional Hill Chart in the Condition Monitoring and Cost Estimation of the Francis Turbine Unit
by Bin Jian, Weiqiang Zhao, Rongfu Guo, Shuping Chen, Ming Xia and Zhengwei Wang
Processes 2024, 12(6), 1243; https://doi.org/10.3390/pr12061243 - 17 Jun 2024
Viewed by 150
Abstract
With a large-range-operation head, the Francis turbine unit is the most widely used type of hydraulic turbine in the world. The general range of the Francis turbine is 20–700 m. Because of this, the operating stability of the Francis turbine needs to be [...] Read more.
With a large-range-operation head, the Francis turbine unit is the most widely used type of hydraulic turbine in the world. The general range of the Francis turbine is 20–700 m. Because of this, the operating stability of the Francis turbine needs to be focused on. In this paper, a multi-dimensional hill chart is applied to a low-head Francis turbine unit to describe its vibration characteristics. Firstly, a field test was conducted on the unit in order to obtain vibration data under different operating conditions. Secondly, the condition indicators were calculated and extracted from the experimental data. Then, the condition indicators under different head values and outputs were fitted to form a multi-dimensional hill chart. In the end, the vibration characteristics of the researched low-head Francis turbine unit were analyzed based on the multi-dimensional hill chart. Full article
(This article belongs to the Section Process Control and Monitoring)
33 pages, 1225 KiB  
Review
Nirmatrelvir: From Discovery to Modern and Alternative Synthetic Approaches
by Michela Galli, Francesco Migliano, Valerio Fasano, Alessandra Silvani, Daniele Passarella and Andrea Citarella
Processes 2024, 12(6), 1242; https://doi.org/10.3390/pr12061242 - 17 Jun 2024
Viewed by 204
Abstract
The global urgency in response to the COVID-19 pandemic has catalyzed extensive research into discovering efficacious antiviral compounds against SARS-CoV-2. Among these, Nirmatrelvir (PF-07321332) has emerged as a promising candidate, exhibiting potent antiviral activity by targeting the main protease of SARS-CoV-2, and has [...] Read more.
The global urgency in response to the COVID-19 pandemic has catalyzed extensive research into discovering efficacious antiviral compounds against SARS-CoV-2. Among these, Nirmatrelvir (PF-07321332) has emerged as a promising candidate, exhibiting potent antiviral activity by targeting the main protease of SARS-CoV-2, and has been marketed in combination with ritonavir as the first oral treatment for COVID-19 with the name of PaxlovidTM. This review outlines the synthetic approaches to Nirmatrelvir, ranging from Pfizer’s original method to newer, more sustainable strategies, such as flow chemistry strategies and multicomponent reactions. Each approach’s novelty and contributions to yield and purification processes are highlighted. Additionally, the synthesis of key fragments comprising Nirmatrelvir and innovative optimization strategies are discussed. Full article
(This article belongs to the Special Issue Novel Methodologies for the Synthesis of Bioactive Molecules)
18 pages, 1044 KiB  
Review
A Review of Fracturing and Enhanced Recovery Integration Working Fluids in Tight Reservoirs
by Jianping Shang, Zhengliang Dong, Wenyuan Tan, Yanjun Zhang, Tuo Liang, Liang Xing and Zhaohuan Wang
Processes 2024, 12(6), 1241; https://doi.org/10.3390/pr12061241 - 17 Jun 2024
Viewed by 175
Abstract
Tight reservoirs, characterized by low porosity, low permeability, and difficulty in fluid flow, rely on horizontal wells and large-scale hydraulic fracturing for development. During fracturing, a significant volume of fracturing fluid is injected into the reservoir at a rate far exceeding its absorption [...] Read more.
Tight reservoirs, characterized by low porosity, low permeability, and difficulty in fluid flow, rely on horizontal wells and large-scale hydraulic fracturing for development. During fracturing, a significant volume of fracturing fluid is injected into the reservoir at a rate far exceeding its absorption capacity. This not only serves to create fractures but also impacts the recovery efficiency of tight reservoirs. Therefore, achieving the integration of fracturing and enhanced recovery functions within the working fluid (fracturing-enhanced recovery integration) becomes particularly crucial. This study describes the concept and characteristics of fracturing-enhanced recovery integration and analyzes the types and features of working fluids. We also discuss the challenges and prospects faced by these fluids. Working fluids for fracturing-enhanced recovery integration need to consider the synergistic effects of fracturing and recovery; meet the performance requirements during fracturing stages such as fracture creation, proppant suspension, and flowback; and also address the demand for increased recovery. The main mechanisms include (1) enlarging the effective pore radius, (2) super-hydrophobic effects, and (3) anti-swelling properties. Fracturing fluids are pumped into fractures through pipelines, where they undergo complex flow in multi-scale fractures, ultimately seeping through capillary bundles. Flow resistance is influenced by the external environment, and the sources of flow resistance in fractures of different scales vary. Surfactants with polymerization capabilities, biodegradable and environmentally friendly bio-based surfactants, crosslinking agents, and amino acid-based green surfactants with outstanding properties will unleash their application potential, providing crucial support for the effectiveness of fracturing-enhanced recovery integration working fluids. This article provides important references for the green, efficient, and sustainable development of tight oil reservoirs. Full article
(This article belongs to the Section Energy Systems)
16 pages, 5525 KiB  
Article
Analysis of Fault Influence on Geostress Perturbation Based on Fault Model Test
by Shuang Tian, Yan Qiao, Yang Zhang, Dawei Hu, Hui Zhou and Sayed Muhammad Iqbal
Processes 2024, 12(6), 1240; https://doi.org/10.3390/pr12061240 - 17 Jun 2024
Viewed by 197
Abstract
The distribution of the geostress field in reservoirs holds significant implications for the precise exploration and efficient development and utilization of oil and gas resources, especially in deep strata regions where faults are prevalent. Geological structural movements in these deep strata regions exacerbate [...] Read more.
The distribution of the geostress field in reservoirs holds significant implications for the precise exploration and efficient development and utilization of oil and gas resources, especially in deep strata regions where faults are prevalent. Geological structural movements in these deep strata regions exacerbate the complexity of geostress field distributions. To elucidate the perturbation of the geostress field in deep reservoirs caused by faults, this study initially conducted a series of physical model tests on single fault dislocation, employing digital image correlation techniques to capture the displacement fields of various types of fault dislocations. Subsequently, a numerical model of the fault interface element was established, and fault element parameters were determined through sensitivity analysis and trial calculation. This study further analyzed the perturbation of the geostress field using this numerical model. Finally, a multi-fault numerical simulation model was constructed to clarify the perturbations in the regional geostress field under the influence of multiple faults. The results indicate that the geostress perturbation range under the action of multiple faults spans from 183.06 to 310.06 m. Full article
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31 pages, 13784 KiB  
Article
Numerical Simulation and Experimental Study of Gas–Solid Two-Phase Spraying of Dry Powder Fire-Extinguishing System Based on Fire-Extinguishing Inspection Robot
by Shengli Chu, Tao Chen, Yifan Gan, Yixin Liu, Wenpei Zheng, Yan Tang and Wendong Zhou
Processes 2024, 12(6), 1239; https://doi.org/10.3390/pr12061239 - 17 Jun 2024
Viewed by 214
Abstract
In order to solve the problem where the traditional intelligent inspection robot only has a single inspection function, we studied the use of a dry powder (including an ultra-fine dry powder) as a fire-extinguishing medium for the first time. In fire-extinguishing robots, the [...] Read more.
In order to solve the problem where the traditional intelligent inspection robot only has a single inspection function, we studied the use of a dry powder (including an ultra-fine dry powder) as a fire-extinguishing medium for the first time. In fire-extinguishing robots, the spray pressure is difficult to control, and there are several other issues. For integrated inspection, an intelligent, nitrogen-driven fire-extinguishing robot using a dry powder in a pressure-controlled spray was developed. On this basis, in order to investigate nitrogen-driven dry powder particle spraying as a gas–solid two-phase mechanism, as well as the flow characteristics and the influence of relevant parameters on the spraying effect, a nitrogen-driven dry powder particle spraying system was established as part of a gas–solid two-phase computational fluid dynamics model. The flow field of the spraying system and the particle motion characteristics were analyzed to explore the micro-mechanisms of the influence of different driving pressures, pipe diameters, and nozzle configurations on the spraying of the dry powder. In order to investigate the macroscopic effect of dry powder spraying where the gas–solid two-phase micro-mechanisms could not be revealed, an experimental platform was set up, and the experiments verified the accuracy of the numerical simulation results. We also investigated the dry powder spraying effect under different driving pressures, pipe diameters, nozzle configurations, and loading ratios. Finally, an orthogonal test was designed based on the results of the single-factor experiments to find the best combination of parameters required to achieve the optimal spraying effect. The research results can provide a theoretical and technical reference for the design and development of nitrogen-driven dry powder spraying systems. Full article
(This article belongs to the Section Automation Control Systems)
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15 pages, 1294 KiB  
Review
A Review of Supercritical CO2 Fracturing Technology in Shale Gas Reservoirs
by Zhaokai Hou, Yuan Yuan, Ye Chen, Jinyu Feng, Huaishan Wang and Xu Zhang
Processes 2024, 12(6), 1238; https://doi.org/10.3390/pr12061238 - 16 Jun 2024
Viewed by 364
Abstract
Shale gas reservoirs generally exhibit characteristics such as low porosity, permeability, and pore throat radius, with high airflow resistance. Currently, hydraulic fracturing is a commonly used method for commercial shale gas extraction; however, the hydraulic fracturing method has exhibited a series of issues, [...] Read more.
Shale gas reservoirs generally exhibit characteristics such as low porosity, permeability, and pore throat radius, with high airflow resistance. Currently, hydraulic fracturing is a commonly used method for commercial shale gas extraction; however, the hydraulic fracturing method has exhibited a series of issues, including water sensitivity and reservoir pollution in shale reservoirs. Therefore, the development of anhydrous fracturing technology suitable for shale gas reservoirs has become an urgent requirement. The supercritical carbon dioxide fracturing technique has the merits of reducing reservoir damage, improving recovery and backflow rates, and saving water resources. Moreover, this technique has broad application prospects and can achieve the effective extraction of shale gas. To enhance the understanding of the supercritical carbon dioxide fracturing technique, this review summarizes the progress of current research on this technique. Furthermore, this study analyzes the stage control technology of supercritical carbon dioxide during the fracturing process, the interaction characteristics between supercritical carbon dioxide and rocks, and the laws of rock initiation and crack growth in supercritical carbon dioxide fracturing. The outcomes indicate that after SC-CO2 enters the reservoir, CO2 water–rock interaction occurs, which alters the mineral composition and pore throat framework, weakens the mechanical characteristics of shale, reduces the rock fracturing pressure, and increases the complexity of the fracturing network. This article provides a reference for research related to supercritical carbon dioxide fracturing technology and is greatly significant for the development of shale gas reservoirs. Full article
(This article belongs to the Section Particle Processes)
13 pages, 7230 KiB  
Article
Effects of Ti/Al Ratio on Formation of Ti-Al Intermetallics/TiB2 Composites by SHS from Ti-Al-B Powder Mixtures
by Chun-Liang Yeh and Yi-Cheng Chan
Processes 2024, 12(6), 1237; https://doi.org/10.3390/pr12061237 - 16 Jun 2024
Viewed by 305
Abstract
Ti-Al intermetallics/TiB2 composites were prepared from elemental powder mixtures by the method of self-propagating high-temperature synthesis (SHS). Reactant mixtures were formulated to contain two parts; one group was (2Ti + 4B) to form 2TiB2 and the other group was (Ti + [...] Read more.
Ti-Al intermetallics/TiB2 composites were prepared from elemental powder mixtures by the method of self-propagating high-temperature synthesis (SHS). Reactant mixtures were formulated to contain two parts; one group was (2Ti + 4B) to form 2TiB2 and the other group was (Ti + xAl) to produce Ti-Al intermetallic compounds. The content of Al ranged between x = 0.33 and 3.0, which was equivalent to the Ti/Al atomic ratio from Ti-25% Al to Ti-75% Al in the (Ti + xAl) group. The results showed that the increase of Al percentage reduced the overall combustion exothermicity and led to a slower self-sustaining combustion wave speed and a lower combustion temperature. Apparent activation energy of the Ti-Al-B solid-state combustion reaction was determined to be 114.7 kJ/mol by this study. Based on the XRD analysis, Ti-Al intermetallics/TiB2 composites featuring Ti3Al, TiAl, TiAl2, and TiAl3 as the dominant aluminide phase were respectively synthesized from the samples of Ti-25%~40% Al, Ti-50%~60% Al, Ti-71.4% Al, and Ti-75% Al. For the samples of Ti-25% Al and Ti-30% Al, Ti3Al was the only aluminide formed. The microstructure of the composites exhibited that TiB2 grains with a columnar shape of 2‒3 μm in length were well distributed and embedded in the aluminide matrix. This study demonstrated an effective and energy-saving fabrication route for producing Ti-Al intermetallics/TiB2 composites with different dominant aluminide phases. Full article
(This article belongs to the Special Issue Composites by Metallurgy and Combustion Synthesis)
20 pages, 2434 KiB  
Article
Ibuprofen Formulations: Permeability and Biodegradability Comparison Depending on the Type of Formulation
by Edyta Kucharska, Berin Ok, Anna Nowak, Łukasz Kucharski, Anna Muzykiewicz-Szymańska and Paula Ossowicz-Rupniewska
Processes 2024, 12(6), 1236; https://doi.org/10.3390/pr12061236 - 16 Jun 2024
Viewed by 324
Abstract
This study assesses ibuprofen’s permeability to different formulations and their biodegradation. Hydrogel, organogel, Eucerin ointment, silicone ointment, and zinc ointment were investigated. The objective was to comprehensively evaluate the therapeutic efficacy and environmental implications of these formulations. Diverse formulations were examined through the [...] Read more.
This study assesses ibuprofen’s permeability to different formulations and their biodegradation. Hydrogel, organogel, Eucerin ointment, silicone ointment, and zinc ointment were investigated. The objective was to comprehensively evaluate the therapeutic efficacy and environmental implications of these formulations. Diverse formulations were examined through the utilisation of Franz diffusion chambers to evaluate the in vitro permeability of both ibuprofen and ibuprofenate sodium. Moreover, biodegradation studies of the obtained formulations were carried out with activated sludge. The activity of the inoculum was confirmed by using SDS as a reference compound. The experimental settings used (carbon content and inoculum volume) were selected based on the criteria set by the OECD guidelines. Relevant parameters pertaining to the biodegradation process were estimated, including biodegradation values (%B) at specific time points, half-lives of initial compounds and API-containing formulations, and degradation phases (lag phase I; degradation phase II, and plate phase III). For comparison purposes, biodegradation studies were also carried out for the initial IBU and IBUNa compounds under the same conditions. The environmental implications of these findings underscore the need for a balanced consideration of therapeutic efficacy and environmental sustainability in pharmaceutical formulation design. This study provides valuable insights for pharmaceutical researchers, environmental scientists, and regulatory bodies involved in the development and assessment of drug formulations. The proposed method of removing NSAIDs from aquatic ecosystems is a cheaper alternative to techniques such as reverse osmosis, oxidation, UV degradation, or photolysis, which have not found practical use owing to the generation of toxic sludge or high capital and operating costs. Full article
(This article belongs to the Special Issue Advanced Biodegradation Technologies for Environmental Pollutants)
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42 pages, 4200 KiB  
Review
Review of Methods for Obtaining Rare Earth Elements from Recycling and Their Impact on the Environment and Human Health
by Despina A. Gkika, Michail Chalaris and George Z. Kyzas
Processes 2024, 12(6), 1235; https://doi.org/10.3390/pr12061235 - 16 Jun 2024
Viewed by 324
Abstract
Rare earth elements (REEs) are at the forefront of discussions, given their crucial role in cutting-edge and eco-friendly innovations that propel the industrial revolution towards a green economy. These elements have become indispensable to various modern technologies, such as smartphones, electronic devices, and [...] Read more.
Rare earth elements (REEs) are at the forefront of discussions, given their crucial role in cutting-edge and eco-friendly innovations that propel the industrial revolution towards a green economy. These elements have become indispensable to various modern technologies, such as smartphones, electronic devices, and renewable energy sources. Many different concepts and analyses have been introduced, such as the chemical similarities among REEs, health risks and ecological damages, the negative environmental impacts of current recovery processes, and strategies for advancing REE recovery towards a circular economy. Although these elements have been widely used in various applications over the last 20 years, the literature on these aspects is fragmented and spread across different research areas, shared by multiple branches and application fields. These fields include safety concerns, economic challenges, and technology. Summarizing and classifying this literature is challenging due to its fragmented nature, the variety of topics, and the different approaches used. The quest for cleaner recycling strategies necessitates a comprehensive assessment covering economic, technological, and environmental aspects. The primary goal of this review is to provide a holistic perspective on REEs, with a central focus on their economic, technological, and environmental dimensions, particularly emphasizing reuse, recycling, and occupational safety. The review begins by addressing complexities of REEs, highlighting the associated technologies, environmental concerns, and economic considerations. It further explores the aspects of reuse and recycling of REEs, shedding light on the advantages, drawbacks, hazards, and costs associated with recycling technologies for REE recovery. Additionally, the review summarizes occupational exposure and safety considerations related to REEs. Full article
(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))
15 pages, 6157 KiB  
Article
Investigation of the Dominant Effects of Non-Spherical Particles on Particle–Wall Collisions
by Zhoutao Cen, Yuxin Wu, Jingyu Wang, Jie Liu, Minmin Zhou, Shukuan Chen and Dongqiang Zhao
Processes 2024, 12(6), 1234; https://doi.org/10.3390/pr12061234 - 16 Jun 2024
Viewed by 220
Abstract
A deep understanding of the particle–wall collision (PWC) behaviors of non-spherical particles is important for managing gas–solid flows in industrial applications. It is important to identify the dominant parameters and to develop the common PWC prediction models for typical non-spherical particles. In this [...] Read more.
A deep understanding of the particle–wall collision (PWC) behaviors of non-spherical particles is important for managing gas–solid flows in industrial applications. It is important to identify the dominant parameters and to develop the common PWC prediction models for typical non-spherical particles. In this paper, different types of non-spherical particles were used to conduct the fundamental experiments. The effects of key parameters such as particle size, non-sphericity, wall roughness, and impact angle were analyzed. The results show that the trends of the collision coefficients with the impact angle for all non-spherical particles are similar. The dominant factors of particle–wall collisions are particle sphericity and wall roughness. A model with four parameters was fitted from the experimental data. The model can predict the collisions of non-spherical particles on rough steel walls with sizes ranging from 50 to 550 microns. Full article
(This article belongs to the Special Issue Separation Processes for Environmental Preservation)
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15 pages, 490 KiB  
Article
Reaction–Thin Film Evaporation Coupling Technology for Highly Efficient Synthesis of Higher Alkyl Methacrylate
by Lele Liu, Yao Zhang, Shuo Su, Kun Yu, Fengmin Nie and Yong Li
Processes 2024, 12(6), 1233; https://doi.org/10.3390/pr12061233 - 15 Jun 2024
Viewed by 356
Abstract
The traditional methacrylic esterification process, which couples reaction–distillation/rectification, suffers from issues such as prolonged reaction time, high risk of self-polymerization, and low utilization rate of methacrylic acid. By optimizing the esterification reaction of methacrylic acid through reaction–thin film evaporation coupling, compared to the [...] Read more.
The traditional methacrylic esterification process, which couples reaction–distillation/rectification, suffers from issues such as prolonged reaction time, high risk of self-polymerization, and low utilization rate of methacrylic acid. By optimizing the esterification reaction of methacrylic acid through reaction–thin film evaporation coupling, compared to the reaction–distillation coupling process, the reaction time could be reduced by 37.50%, the reaction temperature could be lowered by over 15 °C, and the yield of etherification of dodecanol could be decreased by 81.25%, which significantly mitigates the risk of self-aggregation and reduces energy consumption. Furthermore, the feasibility of recovery of methacrylic acid from aqueous phase through extraction with higher aliphatic alcohol was verified, the recovery rate of methacrylic acid could reach above 96.95%, and the extracted phase could be directly utilized for preparing raw material for esterification reaction without requiring further separation steps, which effectively enhances the process economy and atomic utilization. Full article
(This article belongs to the Special Issue Process Intensification in Chemical Reaction Engineering (Volume II))
17 pages, 5729 KiB  
Article
Optimization Design of Injection Mold Conformal Cooling Channel for Improving Cooling Rate
by Jinyi Li, Yung Chieh Ong and Wan Mansor Wan Muhamad
Processes 2024, 12(6), 1232; https://doi.org/10.3390/pr12061232 - 15 Jun 2024
Viewed by 295
Abstract
Optimizing the design of the conformal cooling channel can increase the cooling rate of injection mold. The aim of this study was the problem of low cooling efficiency of injection mold for deep-cavity plastic parts under the conventional cooling channel. Based on the [...] Read more.
Optimizing the design of the conformal cooling channel can increase the cooling rate of injection mold. The aim of this study was the problem of low cooling efficiency of injection mold for deep-cavity plastic parts under the conventional cooling channel. Based on the analysis of the heat transfer principle of the injection mold, a mathematical description of the cooling time of the conformal cooling channel was made. By designing orthogonal experiments and using simulation methods in the Autodesk Moldflow 2019 software, with the minimum cooling time of the mold as the optimization goal, experimental optimization was carried out for the three design variables of the channel, thereby obtaining the optimal combination of design variables for the conformal cooling channel. The conformal cooling channel layout was innovatively designed, and through computer simulation experiments, it was concluded that the conformal cooling channel adopted a series flat-head layout, which has the shortest cooling time and the fastest cooling rate. Metal additive manufacturing technology was used to complete the manufacturing of the mold insert with the conformal cooling channel. After the trial production of the conformal cooling injection mold, the molding cycle was obviously shortened, and the injection molding production efficiency was significantly improved. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
18 pages, 11511 KiB  
Article
Simulation of Elbow Erosion of Gas–Liquid–Solid Three-Phase Shale Gas Gathering Pipeline Based on CFD-DEM
by Yixuan Wang, Rui Tan, Bei Chang, Bin Chen, Junxiang Li, Qianli Lu and Tao Zhang
Processes 2024, 12(6), 1231; https://doi.org/10.3390/pr12061231 - 15 Jun 2024
Viewed by 207
Abstract
Shale gas gathering pipelines often contain liquid water and solid sand in the early stage of production, which leads to the failure of pipeline components easily under the action of gas–liquid–solid three phases. A computational fluid dynamics (CFD) model based on the fluid [...] Read more.
Shale gas gathering pipelines often contain liquid water and solid sand in the early stage of production, which leads to the failure of pipeline components easily under the action of gas–liquid–solid three phases. A computational fluid dynamics (CFD) model based on the fluid volume method (VOF) and discrete element method (DEM) was established to study the flow law of gas–liquid–solid three-phase flow in the elbow of shale gas gathering pipeline and the erosion law of the inner surface of the elbow was studied by coupling the Oka erosion prediction model. By comparing the experimental results of erosion damage of the elbow, it is found that the model established can well predict the erosion characteristics and erosion amount under the action of three phases. Combined with the field pipeline parameters and operating conditions, the paper further simulates the elbow erosion behavior under relevant working conditions. The results show that the particles rotate clockwise from the outer wall of the pipe through the bottom of the pipe when passing through the elbow under the action of gas and water phases. When the gas velocity increases, the particles at the elbow mainly gather at the bottom of the elbow and the wall of the outer arch. When the water content increases gradually, the particles gathered on the outer arch wall of the elbow move along the outer arch wall of the elbow and face the inner arch surface gradually, and the erosion area is mainly concentrated on the outer arch wall of the elbow and the outlet horizontal pipe. Under the condition of the liquid phase, the movement characteristics of the water phase and particles in the elbow of the gas gathering pipeline and the erosion characteristics of the pipeline surface are obviously different from those under the condition of the gas–solid two-phase. The model and simulation results established in this paper provide a reference for the erosion damage protection of shale gas gathering pipeline elbow. Full article
(This article belongs to the Section Energy Systems)
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19 pages, 934 KiB  
Article
Pricing Strategies for Distribution Network Electric Vehicle Operators Considering the Uncertainty of Renewable Energy
by Xiaodong Yuan, Xize Jiao, Mingshen Wang, Huachun Han, Shukang Lv and Fei Zeng
Processes 2024, 12(6), 1230; https://doi.org/10.3390/pr12061230 - 15 Jun 2024
Viewed by 163
Abstract
In the future, the active load of the distribution network side will be dominated by electric vehicles (EVs), showing that the charging power demand of electric vehicles will change with the change in charging electricity price. With the popularity of electric vehicles in [...] Read more.
In the future, the active load of the distribution network side will be dominated by electric vehicles (EVs), showing that the charging power demand of electric vehicles will change with the change in charging electricity price. With the popularity of electric vehicles in the distribution network, their aggregation operators will play a more prominent role in pricing management and charging behavior, and setting an appropriate charging price can achieve a win–win situation for operators and electric vehicle users. At the same time, the proportion of scenery in the distribution network is relatively high, and the uncertainty of self-output has a certain impact on the pricing strategy of operators and the charging behavior of electric vehicle users, which has become an important research topic. Based on the above background, an EV operator pricing strategy considering the landscape uncertainty is proposed, a Stackelberg game model is established to maximize the respective benefits of operators and EV users, and the two-layer model is further transformed into a single-layer model through the Karush–Kuhn–Tucker (KKT) condition and duality theorem. Finally, the IEEE 33 system is simulated with the CPLEX solver, and the global optimal pricing strategy is obtained. Simulation results prove that electric vehicle operators experience a maximum profit increase of 2.6% due to the impact of maximum capacity of energy storage equipment and the uncertainty of renewable energy output can result in electric vehicle operators losing approximately 20% of their profits at most. Full article
12 pages, 5966 KiB  
Article
Study on the Thermal Expansion Characteristics of Coal during CO2 Adsorption
by Jinxing Song, Yajie Sun and Yufang Liu
Processes 2024, 12(6), 1229; https://doi.org/10.3390/pr12061229 - 15 Jun 2024
Viewed by 165
Abstract
The adsorption of CO2 fracturing fluid into coal reservoirs causes the expansion of the coal matrix volume, resulting in changes in the fracture opening, which alters the permeability of the coal reservoir. However, it is not yet clear whether thermal expansion during [...] Read more.
The adsorption of CO2 fracturing fluid into coal reservoirs causes the expansion of the coal matrix volume, resulting in changes in the fracture opening, which alters the permeability of the coal reservoir. However, it is not yet clear whether thermal expansion during CO2 adsorption on coal is the main cause of coal adsorption expansion. Therefore, by testing the thermal properties, expansion coefficient, and adsorption heat of the three coal samples, the adsorption thermal expansion characteristics of coal and their impact on the permeability of coal reservoirs are clarified. The results reveal the following: (1) Under the same conditions, the adsorption heat increases with increasing pressure, while it decreases with increasing temperature. The relationship between adsorption heat and pressure conforms to the Langmuir equation before 40 °C, and it follows a second-order equation beyond 40 °C. At 100 °C, the adsorption heat of coal samples to CO2 is primarily determined by temperature. (2) The maximum temperature variation in coal samples from Xinjiang, Liulin, and Zhaozhuang during CO2 adsorption is 95.767 °C, 87.463 °C, and 97.8 °C, respectively. The maximum thermal expansion rates are 12.66%, 5.74%, and 14.37%, and the maximum permeability loss rates are 16.16%, 7.51%, and 18.24%, respectively, indicating that thermal expansion is the main reason for coal adsorption expansion. (3) This research can elucidate the impact of CO2 fracturing fluid on coal reservoirs and its potential application value, thus providing theoretical support for coalbed methane development and CO2 geological storage. Full article
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