Journal Description
Processes
Processes
is an international, peer-reviewed, open access journal on processes/systems in chemistry, biology, material, energy, environment, food, pharmaceutical, manufacturing, automation control, catalysis, separation, particle and allied engineering fields published monthly online by MDPI. The Systems and Control Division of the Canadian Society for Chemical Engineering (CSChE S&C Division) and the Brazilian Association of Chemical Engineering (ABEQ) are affiliated with Processes and their members receive discounts on the article processing charges. Please visit Society Collaborations for more details.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), Ei Compendex, Inspec, AGRIS, and other databases.
- Journal Rank: JCR - Q2 (Engineering, Chemical) / CiteScore - Q2 (Chemical Engineering (miscellaneous))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 14.4 days after submission; acceptance to publication is undertaken in 2.6 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
2.8 (2023);
5-Year Impact Factor:
3.0 (2023)
Latest Articles
Deep Neural Network Optimization for Efficient Gas Detection Systems in Edge Intelligence Environments
Processes 2024, 12(12), 2638; https://doi.org/10.3390/pr12122638 - 22 Nov 2024
Abstract
This paper introduces an optimized deep neural network (DNN) framework for an efficient gas detection system applicable across various settings. The proposed optimized DNN model addresses key issues in conventional machine learning (ML), including slow computation times, convergence issues, and poor adaptability to
[...] Read more.
This paper introduces an optimized deep neural network (DNN) framework for an efficient gas detection system applicable across various settings. The proposed optimized DNN model addresses key issues in conventional machine learning (ML), including slow computation times, convergence issues, and poor adaptability to new data, which can result in increased prediction errors and reduced reliability. The proposed framework methodology comprises four phases: data collection, pre-processing, offline DNN training optimization, and online model testing and deployment. The training datasets are collected from seven classes of liquid beverages and environmental air samples using integrated gas sensor devices and an edge intelligence environment. The proposed DNN algorithm is trained on high-performance computing systems by fine-tuning multiple hyperparameter optimization techniques, resulting in an optimized DNN. This well-trained DNN model is validated using unseen new testing datasets in high-performance computing systems. Experimental results demonstrate that the optimized DNN can accurately recognize different beverages, achieving an impressive detection accuracy rate of 98.29%. The findings indicate that the proposed system significantly enhances gas identification capabilities and effectively addresses the slow computation and performance issues associated with traditional ML methods. This work highlights the potential of optimized DNNs to provide reliable and efficient contactless detection solutions across various industries, enhancing real-time gas detection applications.
Full article
(This article belongs to the Special Issue Research on Intelligent Fault Diagnosis Based on Neural Network)
Open AccessArticle
A Study on the Sustainability of Petrochemical Industrial Complexes Through Accident Data Analysis
by
Lee Su Kim, Cheolhee Yoon, Daeun Lee, Gwyam Shin and Seungho Jung
Processes 2024, 12(12), 2637; https://doi.org/10.3390/pr12122637 - 22 Nov 2024
Abstract
The increase in energy demand due to industrial development and urbanization has resulted in the development of large-scale energy facilities. Republic of Korea’s petrochemical industrial complexes serve as prime examples of this phenomenon. However, because of complex processes and aging facilities, many of
[...] Read more.
The increase in energy demand due to industrial development and urbanization has resulted in the development of large-scale energy facilities. Republic of Korea’s petrochemical industrial complexes serve as prime examples of this phenomenon. However, because of complex processes and aging facilities, many of which have been in operation for over a decade, these industrial complexes are prone to process-deviation-related accidents. Chemical accidents in energy facilities involving high-pressure liquids or gases are especially dangerous; therefore, proactive accident prevention is critical. This study is also relevant to corporate environment, social, and governance (ESG) management. Preventing chemical accidents to protect workers from injury is critical for business and preventing damage to surrounding areas from chemical accidents is a key component of ESG safety. In this study, we collected accident data, specifically injury-related incidents, from Republic of Korea’s petrochemical industrial complexes, which are the foundation of the energy industry. We analyzed the causes of accidents in a step-by-step manner. Furthermore, we conducted a risk analysis by categorizing accident data based on the level of risk associated with each analysis result; we identified the main causes of accidents and “high-risk process stages” that posed significant risk. The analysis reveals that the majority of accidents occur during general operations (50%, 167 cases) and process operations (39%, 128 cases). In terms of incident types, fire/explosion incidents accounted for the highest proportion (43%, 144 cases), followed by leakage incidents (24%, 78 cases). Furthermore, we propose a disaster safety artificial intelligence (AI) model to prevent major and fatal accidents during these high-risk process stages. A detailed analysis reveals that human factors such as accumulated worker fatigue, insufficient safety training, and non-compliance with operational procedures can significantly increase the likelihood of accidents in petrochemical facilities. This finding emphasizes the importance of introducing measurement sensors and AI convergence technologies to help humans predict and detect any issues. Therefore, we selected representative accident cases for implementing our disaster safety model.
Full article
(This article belongs to the Section Chemical Processes and Systems)
Open AccessArticle
Comparative Genomic Analysis of Extracellular Electron Transfer in Bacteria
by
Daniel Liu, Jimmy Kuo and Chorng-Horng Lin
Processes 2024, 12(12), 2636; https://doi.org/10.3390/pr12122636 - 22 Nov 2024
Abstract
Certain bacteria can transfer extracellular electrons and are applied in microbial fuel cells (MFCs). In this study, we compared the extracellular electron transfer characteristics of 85 genomes from nine genera, namely Blautia, Bradyrhizobium, Desulfuromonas, Dialister, Geobacter, Geothrix,
[...] Read more.
Certain bacteria can transfer extracellular electrons and are applied in microbial fuel cells (MFCs). In this study, we compared the extracellular electron transfer characteristics of 85 genomes from nine genera, namely Blautia, Bradyrhizobium, Desulfuromonas, Dialister, Geobacter, Geothrix, Shewanella, Sphingomonas, and Phascolarctobacterium, using the bioinformatic tools Prokka 1.14.6, Roary 3.13.0, Panaroo 1.3.4, PEPPAN 1.0.6, and Twilight. The unweighted pair-group method with arithmetic mean (UPGMA) clustering of genes related to extracellular electron transfer revealed a good genus-level structure. The relative abundance and hierarchical clustering analyses performed in this study suggest that the bacteria Desulfuromonas, Geobacter, Geothrix, and Shewanella have more extracellular electron transfer genes and cluster together. Further functional differences among the genomes showed that 66 genes in these bacteria were significantly higher in abundance than in the other five bacteria (p < 0.01) based on PEPPAN followed by a Twilight analysis. Our work provides new potential insights into extracellular electron transfer in microorganisms.
Full article
(This article belongs to the Special Issue Computational Biology Approaches to Genome and Protein Analyzes)
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<p>A workflow for data collection, pangenome, and post-processing analysis. Genomes were downloaded from NCBI with the ncbi-genome-download command and filtered using refseq, all formats, and complete assembly levels. For the <span class="html-italic">Geothrix</span> genus, the assembly levels filtered were “all”. Nine genera were selected for analysis, and the number in the bracket indicates the number of genomes (85 genomes in total). P represents phylum. The ANI was calculated using the pyani program. Protein-coding genes were annotated with the Prokka program followed by a pangenome analysis with the Roary, Panaroo, and PEPPAN programs. The gene_presence_absence matrices generated by Roary and Panaroo were further applied for genes related to the extracellular electron transfer analysis. The Twilight program was then employed for a post-processing analysis based on the trait of extracellular electron transfer followed by a STAMP statistical analysis.</p> Full article ">Figure 2
<p>A dendrogram of the average nucleotide identity (ANI) using percentage identity among genomes. The ANI was calculated using the pyani program with the ANIb command after blastn alignment. An ANI above 95% between two genomes indicated that they are the same species. Each bacterial genus is marked with a different color for visualization.</p> Full article ">Figure 3
<p>The unweighted pair-group mean arithmetic method (UPGMA) clustering of genes related to extracellular electron transfer profiles according to the Dice coefficient. Genes related to extracellular electron transfer were retrieved from the gene_presence_absence matrix of (<b>A</b>) Roary and (<b>B</b>) Panaroo. The binary data were further analyzed using the DGGEstat 1.0 software tool (Eric van Hannen, The Netherlands Institute for Ecological Research, Wageningen, The Netherlands). The bootstrap values (1000 trials) over 50 are shown for nodes. The results of cluster analysis were plotted in iTOL (Interactive Tree of Life) in unrooted mode. Each bacterial genus is marked with a different color for visualization.</p> Full article ">Figure 4
<p>The relative abundance and the hierarchical cluster analysis of genes related to extracellular electron transfer among bacteria. Genes related to extracellular electron transfer were retrieved from the gene_presence_absence matrix of (<b>A</b>) Roary and (<b>B</b>) Panaroo and further analyzed using the classify_genes. R command of the Twilight program based on genus grouping. The y-axis represents the average percentage. Hierarchical clustering was generated in R version 4.3.1 with the scale, dist, and hclust functions in the Euclidean and complete distance methods.</p> Full article ">Figure 5
<p>A heatmap of the genes of (<b>A</b>) Roary, (<b>B</b>) Panaroo, and (<b>C</b>) PEPPAN. The gene_presence_absence matrix from pangenome analyses was further analyzed using the classify_genes. R command of the Twilight program based on genus grouping. Significant genes were identified using the STAMP software package with Welch’s <span class="html-italic">t</span>-test between the E and non-E groups (<span class="html-italic">p</span> < 0.35 for Roary and Panaroo, <span class="html-italic">p</span> < 0.01 for PEPPAN). E represents the bacterial group capable of extracellular electron transfer, and non-E represents the bacterial group not capable of extracellular electron transfer. The abundance scale bar represents the percentage with a blue–white scale. The genes from PEPPAN analysis were obtained through a Blastx (search protein databases using a translated nucleotide query) search of NCBI. The genes were referred to the KEGG pathway maps into metabolism, genetic information processing, environmental information processing, and cellular process pathways with different color codes. Blank denotes that the protein is not classified.</p> Full article ">
<p>A workflow for data collection, pangenome, and post-processing analysis. Genomes were downloaded from NCBI with the ncbi-genome-download command and filtered using refseq, all formats, and complete assembly levels. For the <span class="html-italic">Geothrix</span> genus, the assembly levels filtered were “all”. Nine genera were selected for analysis, and the number in the bracket indicates the number of genomes (85 genomes in total). P represents phylum. The ANI was calculated using the pyani program. Protein-coding genes were annotated with the Prokka program followed by a pangenome analysis with the Roary, Panaroo, and PEPPAN programs. The gene_presence_absence matrices generated by Roary and Panaroo were further applied for genes related to the extracellular electron transfer analysis. The Twilight program was then employed for a post-processing analysis based on the trait of extracellular electron transfer followed by a STAMP statistical analysis.</p> Full article ">Figure 2
<p>A dendrogram of the average nucleotide identity (ANI) using percentage identity among genomes. The ANI was calculated using the pyani program with the ANIb command after blastn alignment. An ANI above 95% between two genomes indicated that they are the same species. Each bacterial genus is marked with a different color for visualization.</p> Full article ">Figure 3
<p>The unweighted pair-group mean arithmetic method (UPGMA) clustering of genes related to extracellular electron transfer profiles according to the Dice coefficient. Genes related to extracellular electron transfer were retrieved from the gene_presence_absence matrix of (<b>A</b>) Roary and (<b>B</b>) Panaroo. The binary data were further analyzed using the DGGEstat 1.0 software tool (Eric van Hannen, The Netherlands Institute for Ecological Research, Wageningen, The Netherlands). The bootstrap values (1000 trials) over 50 are shown for nodes. The results of cluster analysis were plotted in iTOL (Interactive Tree of Life) in unrooted mode. Each bacterial genus is marked with a different color for visualization.</p> Full article ">Figure 4
<p>The relative abundance and the hierarchical cluster analysis of genes related to extracellular electron transfer among bacteria. Genes related to extracellular electron transfer were retrieved from the gene_presence_absence matrix of (<b>A</b>) Roary and (<b>B</b>) Panaroo and further analyzed using the classify_genes. R command of the Twilight program based on genus grouping. The y-axis represents the average percentage. Hierarchical clustering was generated in R version 4.3.1 with the scale, dist, and hclust functions in the Euclidean and complete distance methods.</p> Full article ">Figure 5
<p>A heatmap of the genes of (<b>A</b>) Roary, (<b>B</b>) Panaroo, and (<b>C</b>) PEPPAN. The gene_presence_absence matrix from pangenome analyses was further analyzed using the classify_genes. R command of the Twilight program based on genus grouping. Significant genes were identified using the STAMP software package with Welch’s <span class="html-italic">t</span>-test between the E and non-E groups (<span class="html-italic">p</span> < 0.35 for Roary and Panaroo, <span class="html-italic">p</span> < 0.01 for PEPPAN). E represents the bacterial group capable of extracellular electron transfer, and non-E represents the bacterial group not capable of extracellular electron transfer. The abundance scale bar represents the percentage with a blue–white scale. The genes from PEPPAN analysis were obtained through a Blastx (search protein databases using a translated nucleotide query) search of NCBI. The genes were referred to the KEGG pathway maps into metabolism, genetic information processing, environmental information processing, and cellular process pathways with different color codes. Blank denotes that the protein is not classified.</p> Full article ">
Open AccessArticle
A Novel Approach to Predicting Critical Alternating Stall in a Centrifugal Pump Impeller with Even Blades Under Transient Conditions
by
Xiaojie Zhou, Xulai Chen, Di Yu, Yu Li and Xiaoping Chen
Processes 2024, 12(12), 2635; https://doi.org/10.3390/pr12122635 - 22 Nov 2024
Abstract
A novel approach is proposed to predict alternating stall in a centrifugal pump impeller with even blades by introducing a low-pressure ratio, which is defined as the ratio of the deviation of the low-pressure zones of adjacent impeller passages. The threshold of 2/3
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A novel approach is proposed to predict alternating stall in a centrifugal pump impeller with even blades by introducing a low-pressure ratio, which is defined as the ratio of the deviation of the low-pressure zones of adjacent impeller passages. The threshold of 2/3 is shown to be a good quantity with which to accurately and quantitatively predict alternating stall and even critical alternating stall (CAS). The effectiveness of this new approach is validated by comparison with previous findings obtained under quasi-steady conditions. Large eddy simulation data for a six-blade centrifugal pump impeller are used to predict the CAS under transient conditions, with the transient conditions corresponding to a sinusoidal flow rate with an equilibrium value of 0.5Qd (where Qd is the design load) and an initial phase of zero combined with different oscillation amplitudes. The low-pressure ratio frequency equals the flow rate frequency, approximately 2 Hz. The phase of the low-pressure ratio lags behind the flow rate. When the oscillation amplitude is larger than 0.15Qd, a non-stall state occurs during the dropping stage of the flow rate. The flow rates corresponding to the CAS during the dropping and rising stages, respectively, increase and decrease as the oscillation amplitude increases.
Full article
(This article belongs to the Section Process Control and Monitoring)
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<p>Geometric structure of the centrifugal pump impeller.</p> Full article ">Figure 2
<p>Grids of centrifugal pump impeller: (<b>a</b>) view of centrifugal pump impeller, (<b>b</b>) blade front view, (<b>c</b>) blade middle view.</p> Full article ">Figure 3
<p>Relationship between the flow rate and rotational time under transient conditions. T<sub>0</sub> represents the time of the flow rate for one period.</p> Full article ">Figure 4
<p>Pressure coefficient nephogram in the impeller mid-height plane under quasi-steady conditions at 0.25<span class="html-italic">Q<sub>d</sub></span>. The “a” and “b” represent the impeller passage in the stall state and non-stall state, respectively.</p> Full article ">Figure 5
<p>(<b>a</b>) Relationship between low-pressure ratio and rotational time (the light blue and white ranges represent the stall and non-stall states, respectively) and (<b>b</b>) the pressure coefficient nephogram in the impeller mid-height plane under quasi-steady conditions.</p> Full article ">Figure 6
<p>Pressure coefficient nephogram in the impeller mid-height plane at different rotational times at 0.25<span class="html-italic">Q<sub>d</sub></span>. <span class="html-italic">T</span> represents the time taken for the impeller to rotate 360 degrees.</p> Full article ">Figure 7
<p>Distributions of the pressure coefficients in the impeller mid-height plane at different instantaneous flow rates under transient conditions.</p> Full article ">Figure 8
<p>Distributions of the low-pressure ratio in an oscillation period. The light blue and white ranges represent stall and non-stall states, respectively.</p> Full article ">Figure 9
<p>Flow rates corresponding to critical alternating stall during the dropping stage (<b>left</b>) and rising stage (<b>right</b>).</p> Full article ">Figure 10
<p>Distributions of the pressure coefficient (<b>left</b>) and streamline (<b>right</b>) in the impeller mid-height plane approaching alternate stall. <span class="html-italic">t</span><sub>1</sub> denotes the time corresponding to <span class="html-italic">Q<sub>cd</sub></span>, and <span class="html-italic">t</span><sub>1<span class="html-italic">′</span></sub> equals t<sub>1</sub> − T<sub>0</sub>/36. <span class="html-italic">t</span><sub>2</sub> denotes the time corresponding to <span class="html-italic">Q<sub>cr</sub></span>, and t<sub>2′</sub> equals <span class="html-italic">t</span><sub>2</sub> + T<sub>0</sub>/36.</p> Full article ">Figure 11
<p>Distributions of the low-pressure ratio with an oscillation amplitude of 0.15<span class="html-italic">Q<sub>d</sub></span>. The light blue and white ranges represent the stall and non-stall states, respectively.</p> Full article ">Figure 12
<p>Statistical data of low-pressure ratio for different oscillation amplitude.</p> Full article ">Figure 13
<p>Flow rate corresponding to the critical alternating stall for different oscillation amplitudes.</p> Full article ">
<p>Geometric structure of the centrifugal pump impeller.</p> Full article ">Figure 2
<p>Grids of centrifugal pump impeller: (<b>a</b>) view of centrifugal pump impeller, (<b>b</b>) blade front view, (<b>c</b>) blade middle view.</p> Full article ">Figure 3
<p>Relationship between the flow rate and rotational time under transient conditions. T<sub>0</sub> represents the time of the flow rate for one period.</p> Full article ">Figure 4
<p>Pressure coefficient nephogram in the impeller mid-height plane under quasi-steady conditions at 0.25<span class="html-italic">Q<sub>d</sub></span>. The “a” and “b” represent the impeller passage in the stall state and non-stall state, respectively.</p> Full article ">Figure 5
<p>(<b>a</b>) Relationship between low-pressure ratio and rotational time (the light blue and white ranges represent the stall and non-stall states, respectively) and (<b>b</b>) the pressure coefficient nephogram in the impeller mid-height plane under quasi-steady conditions.</p> Full article ">Figure 6
<p>Pressure coefficient nephogram in the impeller mid-height plane at different rotational times at 0.25<span class="html-italic">Q<sub>d</sub></span>. <span class="html-italic">T</span> represents the time taken for the impeller to rotate 360 degrees.</p> Full article ">Figure 7
<p>Distributions of the pressure coefficients in the impeller mid-height plane at different instantaneous flow rates under transient conditions.</p> Full article ">Figure 8
<p>Distributions of the low-pressure ratio in an oscillation period. The light blue and white ranges represent stall and non-stall states, respectively.</p> Full article ">Figure 9
<p>Flow rates corresponding to critical alternating stall during the dropping stage (<b>left</b>) and rising stage (<b>right</b>).</p> Full article ">Figure 10
<p>Distributions of the pressure coefficient (<b>left</b>) and streamline (<b>right</b>) in the impeller mid-height plane approaching alternate stall. <span class="html-italic">t</span><sub>1</sub> denotes the time corresponding to <span class="html-italic">Q<sub>cd</sub></span>, and <span class="html-italic">t</span><sub>1<span class="html-italic">′</span></sub> equals t<sub>1</sub> − T<sub>0</sub>/36. <span class="html-italic">t</span><sub>2</sub> denotes the time corresponding to <span class="html-italic">Q<sub>cr</sub></span>, and t<sub>2′</sub> equals <span class="html-italic">t</span><sub>2</sub> + T<sub>0</sub>/36.</p> Full article ">Figure 11
<p>Distributions of the low-pressure ratio with an oscillation amplitude of 0.15<span class="html-italic">Q<sub>d</sub></span>. The light blue and white ranges represent the stall and non-stall states, respectively.</p> Full article ">Figure 12
<p>Statistical data of low-pressure ratio for different oscillation amplitude.</p> Full article ">Figure 13
<p>Flow rate corresponding to the critical alternating stall for different oscillation amplitudes.</p> Full article ">
Open AccessArticle
Automatic History Matching Method and Application of Artificial Intelligence for Fractured-Porous Carbonate Reservoirs
by
Kaijun Tong, Wentong Song, Han Chen, Sheng Guo, Xueyuan Li and Zhixue Sun
Processes 2024, 12(12), 2634; https://doi.org/10.3390/pr12122634 - 22 Nov 2024
Abstract
Fractured-porous carbonate reservoirs, mainly composed of dolomites and crystalline rocks with various rock types and extremely poor initial porosity and permeability, are dominated by tectonic fractures and exhibit extreme heterogeneity. The fracture system plays a predominant role in hydrocarbon fluid transport. Compared with
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Fractured-porous carbonate reservoirs, mainly composed of dolomites and crystalline rocks with various rock types and extremely poor initial porosity and permeability, are dominated by tectonic fractures and exhibit extreme heterogeneity. The fracture system plays a predominant role in hydrocarbon fluid transport. Compared with conventional sandstone reservoirs, fracture geometry and topological structure parameters are key factors for the accuracy and computational efficiency of numerical simulation history matching in fractured reservoirs. To address the matching issue, this paper introduces an artificial intelligence history matching method combining the Monte Carlo experimental planning method with an artificial neural network and a particle swarm optimization algorithm. Taking reservoir geological parameters and phase infiltration properties as the objective function, this method performs reservoir production history matching to correct the geological model. Through case studies, it is verified that this method can accurately correct the geological model of fractured-porous reservoirs and match the observed production data. This research represents a collaborative effort among multiple disciplines, integrating advanced algorithms and geological knowledge with the expertise of computer scientists, geologists, and engineers. Currently the world’s major oilfields history fitting is mainly based on reservoir engineers’ experience to fit; the method is applicable to major oilfields, but the fitting accuracy and fitting efficiency is severely limited, the fitting accuracy is less than 75%, while the artificial intelligence history fitting method shows a stronger applicability; intelligent history fitting is mainly based on the integrity of the field data, and as far as the theory is concerned, the accuracy of the intelligent history fitting can be up to 100%. Therefore, AI history fitting can provide a significant foundation for mine field research. Future research could further explore interdisciplinary collaboration to address other challenges in reservoir characterization and management.
Full article
(This article belongs to the Special Issue Quantitative Evaluation, Efficient Development, Seepage, and Simulation of Geo-Energy Resources)
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<p>Schematic diagram of fracture system optimization parameters. (<b>a</b>) Schematic of fractured geological outcrops. (<b>b</b>) Schematic diagram of fracture network system. (<b>c</b>) Simplified 2D fracture system diagram.</p> Full article ">Figure 2
<p>Classification of fracture strike. (<b>a</b>) Fault-fracture model; (<b>b</b>) fracture dip deviation; (<b>c</b>) imaging logging; (<b>d</b>) fracture path; (<b>e</b>) fracture inclination.</p> Full article ">Figure 3
<p>Schematic diagram of multi-superposition BP artificial neural network.</p> Full article ">Figure 4
<p>History matching flow chart of fractured-porous carbonate reservoir.</p> Full article ">Figure 5
<p>Location of the study area.</p> Full article ">Figure 6
<p>Part of the structural horizon and structural model of the well area A. (<b>a</b>) reservoir fracture profiles, (<b>b</b>) constructed (t1), (<b>c</b>) constructed (t2), (<b>d</b>) constructed (t4), (<b>e</b>) constructed (t5).</p> Full article ">Figure 7
<p>Diagram of phase permeability curve of well area A. (<b>a</b>) Facies permeability curve of bedrock system (multiple groups). (<b>b</b>) Phase permeability curve of fracture system.</p> Full article ">Figure 8
<p>Schematic diagram of Well A-9 structure and fracture distribution (prediction). (<b>a</b>) Well A-9 location and tectonic features; (<b>b</b>) randomized fracture system (RFS); (<b>c</b>) DFN model of Well A-9.</p> Full article ">Figure 9
<p>A-9 schematic of the permeability field of a typical well fracture system (part). (<b>a</b>–<b>c</b>) is the analysis of fracture density and width effects considering a constant length. (<b>d</b>–<b>f</b>) A is the analysis of the fracture density and length effects considering a constant width. (<b>g</b>–<b>i</b>) A is the analysis of fracture length and width effects considering constant density.</p> Full article ">Figure 10
<p>A-9 schematic diagram of preliminary matching of typical wells.</p> Full article ">Figure 11
<p>Monte Carlo preferred fracture system permeability modeling. (<b>a</b>–<b>d</b>) represents the effect of analysed crack length, width and density on permeability.</p> Full article ">Figure 12
<p>Parameter correlation diagram (A-9).</p> Full article ">Figure 13
<p>Schematic diagram of the optimal matching series (<b>a</b>) and optimal fracture system (<b>b</b>) in Well A-9.</p> Full article ">Figure 14
<p>Schematic diagram of fracture system permeability field in well area A (part). (<b>a</b>–<b>c</b>) is the analysis of fracture density and width effects considering a constant length. (<b>d</b>–<b>f</b>) A is the analysis of the fracture density and length effects considering a constant width. (<b>g</b>–<b>i</b>) A is the analysis of fracture length and width effects considering constant density.</p> Full article ">Figure 15
<p>Monte Carlo experimental planning for single-well matching curves (<b>a</b>–<b>f</b>) represents the historical fit of different producing wells in the well area.</p> Full article ">Figure 16
<p>Correlation diagram of matching parameters in well area A.</p> Full article ">Figure 17
<p>Typical well optimization history fit curve for well area A. (<b>a</b>–<b>f</b>) represents the historical fit of different producing wells in the well area.</p> Full article ">Figure 18
<p>Schematic diagram of the optimized fracture system model in Well A. (<b>a</b>) Permeability diagram of fracture system (X). (<b>b</b>) High precision matching diagram of well area A.</p> Full article ">
<p>Schematic diagram of fracture system optimization parameters. (<b>a</b>) Schematic of fractured geological outcrops. (<b>b</b>) Schematic diagram of fracture network system. (<b>c</b>) Simplified 2D fracture system diagram.</p> Full article ">Figure 2
<p>Classification of fracture strike. (<b>a</b>) Fault-fracture model; (<b>b</b>) fracture dip deviation; (<b>c</b>) imaging logging; (<b>d</b>) fracture path; (<b>e</b>) fracture inclination.</p> Full article ">Figure 3
<p>Schematic diagram of multi-superposition BP artificial neural network.</p> Full article ">Figure 4
<p>History matching flow chart of fractured-porous carbonate reservoir.</p> Full article ">Figure 5
<p>Location of the study area.</p> Full article ">Figure 6
<p>Part of the structural horizon and structural model of the well area A. (<b>a</b>) reservoir fracture profiles, (<b>b</b>) constructed (t1), (<b>c</b>) constructed (t2), (<b>d</b>) constructed (t4), (<b>e</b>) constructed (t5).</p> Full article ">Figure 7
<p>Diagram of phase permeability curve of well area A. (<b>a</b>) Facies permeability curve of bedrock system (multiple groups). (<b>b</b>) Phase permeability curve of fracture system.</p> Full article ">Figure 8
<p>Schematic diagram of Well A-9 structure and fracture distribution (prediction). (<b>a</b>) Well A-9 location and tectonic features; (<b>b</b>) randomized fracture system (RFS); (<b>c</b>) DFN model of Well A-9.</p> Full article ">Figure 9
<p>A-9 schematic of the permeability field of a typical well fracture system (part). (<b>a</b>–<b>c</b>) is the analysis of fracture density and width effects considering a constant length. (<b>d</b>–<b>f</b>) A is the analysis of the fracture density and length effects considering a constant width. (<b>g</b>–<b>i</b>) A is the analysis of fracture length and width effects considering constant density.</p> Full article ">Figure 10
<p>A-9 schematic diagram of preliminary matching of typical wells.</p> Full article ">Figure 11
<p>Monte Carlo preferred fracture system permeability modeling. (<b>a</b>–<b>d</b>) represents the effect of analysed crack length, width and density on permeability.</p> Full article ">Figure 12
<p>Parameter correlation diagram (A-9).</p> Full article ">Figure 13
<p>Schematic diagram of the optimal matching series (<b>a</b>) and optimal fracture system (<b>b</b>) in Well A-9.</p> Full article ">Figure 14
<p>Schematic diagram of fracture system permeability field in well area A (part). (<b>a</b>–<b>c</b>) is the analysis of fracture density and width effects considering a constant length. (<b>d</b>–<b>f</b>) A is the analysis of the fracture density and length effects considering a constant width. (<b>g</b>–<b>i</b>) A is the analysis of fracture length and width effects considering constant density.</p> Full article ">Figure 15
<p>Monte Carlo experimental planning for single-well matching curves (<b>a</b>–<b>f</b>) represents the historical fit of different producing wells in the well area.</p> Full article ">Figure 16
<p>Correlation diagram of matching parameters in well area A.</p> Full article ">Figure 17
<p>Typical well optimization history fit curve for well area A. (<b>a</b>–<b>f</b>) represents the historical fit of different producing wells in the well area.</p> Full article ">Figure 18
<p>Schematic diagram of the optimized fracture system model in Well A. (<b>a</b>) Permeability diagram of fracture system (X). (<b>b</b>) High precision matching diagram of well area A.</p> Full article ">
Open AccessArticle
Experimental Investigation into Atmospheric Microwave Plasma-Driven Nitrogen Fixation Using Metal–Organic Frameworks
by
Fang Zheng, Kai Feng, Shaokun Wu and Wei Xiao
Processes 2024, 12(12), 2633; https://doi.org/10.3390/pr12122633 - 22 Nov 2024
Abstract
Microwave plasma-driven nitrogen fixation can occur at atmospheric pressure without complex processing conditions. However, this method still faces the challenge of high energy consumption and low production. Combined plasma–catalyst systems are widely used to increase production and reduce energy consumption in nitrogen fixation.
[...] Read more.
Microwave plasma-driven nitrogen fixation can occur at atmospheric pressure without complex processing conditions. However, this method still faces the challenge of high energy consumption and low production. Combined plasma–catalyst systems are widely used to increase production and reduce energy consumption in nitrogen fixation. However, the efficacy of currently used catalysts remains limited. In this paper, the metal–organic framework materials (MOFs) copper benzene-1,3,5-tricarboxylate (Cu-BTC) and zeolitic imidazolate framework-8 (ZIF-8) are combined with atmospheric microwave plasma for nitrogen fixation. The experimental results show that they have a better catalytic effect than the ordinary catalyst zeolite socony mobil-5 (ZSM-5). The maximum nitrogen oxide concentration reaches 33,400 ppm, and the lowest energy consumption is 2.05 MJ/mol. Compared to no catalyst, the production of nitrogen oxides (NOx) can be increased by 17.1%, and the energy consumption can be reduced by 14.6%. The stability test carried out these catalysts demonstrates that they have a stable performance within one hour. To the knowledge of the authors, this is the first effort to study the synergistic effects of atmospheric microwave plasma and MOFs on nitrogen fixation. This study also introduces a potentially eco-friendly approach to nitrogen fixation, characterized by its low energy consumption and emissions.
Full article
(This article belongs to the Section Chemical Processes and Systems)
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Figure 1
<p>Photograph of the experimental system.</p> Full article ">Figure 2
<p>Photographs of three catalysts prior to usage.</p> Full article ">Figure 3
<p>The <span class="html-italic">x</span>-<span class="html-italic">z</span> plane of the 3D computational model of temperature distribution in plasma and its downstream area.</p> Full article ">Figure 4
<p>(<b>a</b>) Mesh diagram used in the simulation, and (<b>b</b>) the mesh sensitivity test.</p> Full article ">Figure 5
<p>Temperature distribution in (<b>a</b>) 3D model, (<b>b</b>) <span class="html-italic">x</span>-<span class="html-italic">z</span> plane and (<b>c</b>) <span class="html-italic">x</span>-<span class="html-italic">y</span> plane (unit: °C).</p> Full article ">Figure 6
<p>Gas temperature at the <span class="html-italic">z</span>-axis in the quartz tube.</p> Full article ">Figure 7
<p>The streamline chart for the inflow rate 7 L/min.</p> Full article ">Figure 8
<p>Infrared absorption spectrum of the gas generated using the atmospheric microwave plasma.</p> Full article ">Figure 9
<p>Infrared absorption spectra of (<b>a</b>) NO and (<b>c</b>) NO<sub>2</sub> with standard concentrations and the calibration curves of (<b>b</b>) NO and (<b>d</b>) NO<sub>2</sub>.</p> Full article ">Figure 10
<p>NO<sub>x</sub> concentration at different gas flow rates and microwave powers of (<b>a</b>) 450 W, (<b>b</b>) 550 W, (<b>c</b>) 650 W, and (<b>d</b>) 700 W.</p> Full article ">Figure 11
<p>Energy consumption with different gas flow rates and microwave powers of (<b>a</b>) 450 W, (<b>b</b>) 550 W, (<b>c</b>) 650 W, and (<b>d</b>) 700 W.</p> Full article ">Figure 12
<p>NO<sub>x</sub> concentration produced during a 60 min operation with these three catalysts.</p> Full article ">
<p>Photograph of the experimental system.</p> Full article ">Figure 2
<p>Photographs of three catalysts prior to usage.</p> Full article ">Figure 3
<p>The <span class="html-italic">x</span>-<span class="html-italic">z</span> plane of the 3D computational model of temperature distribution in plasma and its downstream area.</p> Full article ">Figure 4
<p>(<b>a</b>) Mesh diagram used in the simulation, and (<b>b</b>) the mesh sensitivity test.</p> Full article ">Figure 5
<p>Temperature distribution in (<b>a</b>) 3D model, (<b>b</b>) <span class="html-italic">x</span>-<span class="html-italic">z</span> plane and (<b>c</b>) <span class="html-italic">x</span>-<span class="html-italic">y</span> plane (unit: °C).</p> Full article ">Figure 6
<p>Gas temperature at the <span class="html-italic">z</span>-axis in the quartz tube.</p> Full article ">Figure 7
<p>The streamline chart for the inflow rate 7 L/min.</p> Full article ">Figure 8
<p>Infrared absorption spectrum of the gas generated using the atmospheric microwave plasma.</p> Full article ">Figure 9
<p>Infrared absorption spectra of (<b>a</b>) NO and (<b>c</b>) NO<sub>2</sub> with standard concentrations and the calibration curves of (<b>b</b>) NO and (<b>d</b>) NO<sub>2</sub>.</p> Full article ">Figure 10
<p>NO<sub>x</sub> concentration at different gas flow rates and microwave powers of (<b>a</b>) 450 W, (<b>b</b>) 550 W, (<b>c</b>) 650 W, and (<b>d</b>) 700 W.</p> Full article ">Figure 11
<p>Energy consumption with different gas flow rates and microwave powers of (<b>a</b>) 450 W, (<b>b</b>) 550 W, (<b>c</b>) 650 W, and (<b>d</b>) 700 W.</p> Full article ">Figure 12
<p>NO<sub>x</sub> concentration produced during a 60 min operation with these three catalysts.</p> Full article ">
Open AccessArticle
Design and Parametric Analysis of the Constant Force Characteristics of the Electromagnet for Hydraulic Valves
by
Wang Ren, Liujie Wu, Wei Zhang, Pengfei Jiang, Ziyue Wang, Chao Luo, Jichang Guo, Chang Liu, Yaozhong Wei, Zhiliang Chen, Zongke He, Yijie Liu, Ting Yu, Yanhe Song and Bin Yu
Processes 2024, 12(12), 2632; https://doi.org/10.3390/pr12122632 - 22 Nov 2024
Abstract
The electromagnet is the most used driving device for hydraulic valves; especially the proportional electromagnet with constant force characteristics is the basis for the excellent control performance of hydraulic valves. However, the constant force characteristics of the proportional electromagnet are related to many
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The electromagnet is the most used driving device for hydraulic valves; especially the proportional electromagnet with constant force characteristics is the basis for the excellent control performance of hydraulic valves. However, the constant force characteristics of the proportional electromagnet are related to many parameters and are difficult to obtain. In view of the above problems, this paper designs a proportional electromagnet for driving hydraulic valves with the goal of constant force characteristics, with the minimum variance of the output electromagnetic force in the working range as the condition. Firstly, this paper introduces the working principle of proportional electromagnets and establishes the model of electromagnetic force. Then, the influences of the basin bottom radius, the guide angle width and the basin mouth depth on the constant force characteristics of the electromagnet were studied by the finite element method (FEM). Their values are found respectively to give the electromagnet constant force characteristics. Finally, the test bench of the electromagnet was built, and its constant force characteristics and output characteristics were continuously tested. The results show that the test results of the output electromagnet force are highly consistent with the simulation results and have constant force characteristics. Related research deepens the understanding of how the key parameters affect the constant force characteristics, and helps designers optimize these parameters to develop new structures, which have certain practical engineering values.
Full article
(This article belongs to the Section Energy Systems)
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Figure 1
<p>Structure diagram of electromagnet. (<b>a</b>) Electromagnet structure plane diagram. (<b>b</b>) Electromagnet structure stereogram.</p> Full article ">Figure 2
<p>Magnetic circuit diagram of proportional electromagnets.</p> Full article ">Figure 3
<p>Electromagnetic force of proportional electromagnets.</p> Full article ">Figure 4
<p>The equivalent circuit of the coil.</p> Full article ">Figure 5
<p>Magnetic circuit analysis diagram of electromagnet.</p> Full article ">Figure 6
<p>Structural parameters of electromagnet.</p> Full article ">Figure 7
<p>Electromagnet finite element simulation model and meshing. (<b>a</b>) Electromagnet finite element simulation model. (<b>b</b>) Electromagnet meshing.</p> Full article ">Figure 8
<p>Influence of <span class="html-italic">r</span><sub>4</sub> on electromagnetic force.</p> Full article ">Figure 9
<p>Influence of <span class="html-italic">r</span><sub>4</sub> on the variance of electromagnetic force.</p> Full article ">Figure 10
<p>Influence of <span class="html-italic">l</span><sub>3</sub> on electromagnetic force.</p> Full article ">Figure 11
<p>Influence of <span class="html-italic">l</span><sub>3</sub> on the variance of electromagnetic force.</p> Full article ">Figure 12
<p>Influence of <span class="html-italic">l</span><sub>4</sub> on electromagnetic force.</p> Full article ">Figure 13
<p>Influence of <span class="html-italic">l</span><sub>4</sub> on the variance of electromagnetic force.</p> Full article ">Figure 14
<p>The distribution of magnetic field lines and magnetic induction intensity when different currents are input. (A stands for magnetic flux and B stands for magnetic induction).</p> Full article ">Figure 15
<p>Distribution of magnetic field line and magnetic induction intensity of armature at different positions.</p> Full article ">Figure 16
<p>Displacement–force characteristic simulation curve of electromagnet.</p> Full article ">Figure 17
<p>The current–force characteristic curve of electromagnet.</p> Full article ">Figure 18
<p>Electromagnetic force test bench.</p> Full article ">Figure 19
<p>Current waveform of the coil.</p> Full article ">Figure 20
<p>Displacement–force characteristic test curve of electromagnet.</p> Full article ">Figure 21
<p>The variance of electromagnetic force under different currents.</p> Full article ">Figure 22
<p>The curve of the average electromagnetic force under different currents.</p> Full article ">Figure 23
<p>Current–force characteristic test and simulation comparison curve of electromagnet.</p> Full article ">
<p>Structure diagram of electromagnet. (<b>a</b>) Electromagnet structure plane diagram. (<b>b</b>) Electromagnet structure stereogram.</p> Full article ">Figure 2
<p>Magnetic circuit diagram of proportional electromagnets.</p> Full article ">Figure 3
<p>Electromagnetic force of proportional electromagnets.</p> Full article ">Figure 4
<p>The equivalent circuit of the coil.</p> Full article ">Figure 5
<p>Magnetic circuit analysis diagram of electromagnet.</p> Full article ">Figure 6
<p>Structural parameters of electromagnet.</p> Full article ">Figure 7
<p>Electromagnet finite element simulation model and meshing. (<b>a</b>) Electromagnet finite element simulation model. (<b>b</b>) Electromagnet meshing.</p> Full article ">Figure 8
<p>Influence of <span class="html-italic">r</span><sub>4</sub> on electromagnetic force.</p> Full article ">Figure 9
<p>Influence of <span class="html-italic">r</span><sub>4</sub> on the variance of electromagnetic force.</p> Full article ">Figure 10
<p>Influence of <span class="html-italic">l</span><sub>3</sub> on electromagnetic force.</p> Full article ">Figure 11
<p>Influence of <span class="html-italic">l</span><sub>3</sub> on the variance of electromagnetic force.</p> Full article ">Figure 12
<p>Influence of <span class="html-italic">l</span><sub>4</sub> on electromagnetic force.</p> Full article ">Figure 13
<p>Influence of <span class="html-italic">l</span><sub>4</sub> on the variance of electromagnetic force.</p> Full article ">Figure 14
<p>The distribution of magnetic field lines and magnetic induction intensity when different currents are input. (A stands for magnetic flux and B stands for magnetic induction).</p> Full article ">Figure 15
<p>Distribution of magnetic field line and magnetic induction intensity of armature at different positions.</p> Full article ">Figure 16
<p>Displacement–force characteristic simulation curve of electromagnet.</p> Full article ">Figure 17
<p>The current–force characteristic curve of electromagnet.</p> Full article ">Figure 18
<p>Electromagnetic force test bench.</p> Full article ">Figure 19
<p>Current waveform of the coil.</p> Full article ">Figure 20
<p>Displacement–force characteristic test curve of electromagnet.</p> Full article ">Figure 21
<p>The variance of electromagnetic force under different currents.</p> Full article ">Figure 22
<p>The curve of the average electromagnetic force under different currents.</p> Full article ">Figure 23
<p>Current–force characteristic test and simulation comparison curve of electromagnet.</p> Full article ">
Open AccessArticle
Comprehensive Analysis of the Annulus Pressure Buildup in Wells with Sustained Gas Leakage Below the Liquid Level
by
Siqi Yang, Jianglong Fu, Nan Zhao, Changfeng Xu, Lihong Han, Jianjun Wang, Hailong Liu, Yuhang Zhang and Jun Liu
Processes 2024, 12(12), 2631; https://doi.org/10.3390/pr12122631 - 22 Nov 2024
Abstract
During the process of natural gas development, sustained casing pressure (SCP) frequently occurs within the annulus of the gas wells; we specifically referred to the “A” annular space located between the tubing and the production casing in this paper. SCP in an annulus
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During the process of natural gas development, sustained casing pressure (SCP) frequently occurs within the annulus of the gas wells; we specifically referred to the “A” annular space located between the tubing and the production casing in this paper. SCP in an annulus poses a paramount safety challenge, universally acknowledged as a significant threat to gas field development and production, jeopardizing well integrity, personnel safety, and environmental protection. There are multiple factors that contribute to this issue. Due to the multitude of factors contributing to SCP in an annulus and the unclear mechanisms underlying the pressure buildup in wells, an early assessment of downhole leakage risks remains challenging. Hence, this study focused on a comprehensive analysis of the SCP in the annulus of gas wells. A detailed experimental study on the pressure buildup in an annulus due to tubing leakage below the liquid level was conducted, and the variation patterns of the annulus pressure under various leakage conditions were explored. The findings indicated that the equilibrium attainment time of annulus pressure at the wellhead subsequent to tubing leakage decreases with the increase in the pressure difference between the tubing and the casing, the liquid level height, the leakage orifice diameter, and the quantity, while it increases with the increase in the leakage position and gas temperature. According to the theory of gas fluid dynamics, a predictive model of the annulus pressure buildup with sustained gas leakage below the liquid level was proposed, which was well-validated against experimental results, achieving a model accuracy of over 95%. This study provided a theoretical framework for diagnosing SCP in the annulus of gas wells and developing mitigation strategies, thereby contributing to the advancement of the research field and ensuring the safety of industrial operations.
Full article
(This article belongs to the Special Issue Risk Assessment and System Safety in the Process Industry)
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Figure 1
<p>Schematic diagram of SCP in the annulus of gas well.</p> Full article ">Figure 2
<p>Schematic diagram of the test apparatus for simulating the SCP in the annulus.</p> Full article ">Figure 3
<p>The variation in annular pressure at the wellhead under different pressure differences between the tubing and casing.</p> Full article ">Figure 4
<p>The variation in annular pressure at the wellhead under different liquid level heights.</p> Full article ">Figure 5
<p>The variation in annular pressure at the wellhead under different gas temperatures.</p> Full article ">Figure 6
<p>The variation in the annular pressure at the wellhead under different leakage positions.</p> Full article ">Figure 7
<p>The variation in the annular pressure at the wellhead under leakage orifice diameter.</p> Full article ">Figure 8
<p>The schematic diagram of the five leakage scenarios: (<b>a</b>) one leakage orifice (leakage position is 0.6 m), (<b>b</b>) two leakage orifices (leakage positions are 0.3 m and 0.6 m), (<b>c</b>) two leakage orifices (leakage positions are 0.3 m and 1.0 m), (<b>d</b>) two leakage orifices (leakage positions are 0.6 m and 1.0 m), (<b>e</b>) three leakage orifice (leakage positions are 0.3 m, 0.6 m, and 1.0 m).</p> Full article ">Figure 9
<p>The variation in the annular pressure at the wellhead under leakage orifice quantity.</p> Full article ">Figure 10
<p>Flow chart of the predictive model of the pressure buildup in the annulus.</p> Full article ">Figure 11
<p>Comparison of the variation in annular pressure at the wellhead after gas leakage. (Test conditions: liquid level height is 1.5 m, pressure difference between the tubing and casing is 300 KPa, gas temperature is 25 °C, position of the single leakage orifice is 0.6 m, and its diameter is 1 mm).</p> Full article ">Figure 12
<p>Comparison of the predictive model and experimental results in the (<b>a</b>) equilibrium attainment time and the (<b>b</b>) equilibrium value of the annular pressure at the wellhead.</p> Full article ">
<p>Schematic diagram of SCP in the annulus of gas well.</p> Full article ">Figure 2
<p>Schematic diagram of the test apparatus for simulating the SCP in the annulus.</p> Full article ">Figure 3
<p>The variation in annular pressure at the wellhead under different pressure differences between the tubing and casing.</p> Full article ">Figure 4
<p>The variation in annular pressure at the wellhead under different liquid level heights.</p> Full article ">Figure 5
<p>The variation in annular pressure at the wellhead under different gas temperatures.</p> Full article ">Figure 6
<p>The variation in the annular pressure at the wellhead under different leakage positions.</p> Full article ">Figure 7
<p>The variation in the annular pressure at the wellhead under leakage orifice diameter.</p> Full article ">Figure 8
<p>The schematic diagram of the five leakage scenarios: (<b>a</b>) one leakage orifice (leakage position is 0.6 m), (<b>b</b>) two leakage orifices (leakage positions are 0.3 m and 0.6 m), (<b>c</b>) two leakage orifices (leakage positions are 0.3 m and 1.0 m), (<b>d</b>) two leakage orifices (leakage positions are 0.6 m and 1.0 m), (<b>e</b>) three leakage orifice (leakage positions are 0.3 m, 0.6 m, and 1.0 m).</p> Full article ">Figure 9
<p>The variation in the annular pressure at the wellhead under leakage orifice quantity.</p> Full article ">Figure 10
<p>Flow chart of the predictive model of the pressure buildup in the annulus.</p> Full article ">Figure 11
<p>Comparison of the variation in annular pressure at the wellhead after gas leakage. (Test conditions: liquid level height is 1.5 m, pressure difference between the tubing and casing is 300 KPa, gas temperature is 25 °C, position of the single leakage orifice is 0.6 m, and its diameter is 1 mm).</p> Full article ">Figure 12
<p>Comparison of the predictive model and experimental results in the (<b>a</b>) equilibrium attainment time and the (<b>b</b>) equilibrium value of the annular pressure at the wellhead.</p> Full article ">
Open AccessArticle
Numerical Investigation of Complex Hydraulic Fracture Propagation in Shale Formation
by
Heng Zheng, Fengxia Li and Di Wang
Processes 2024, 12(12), 2630; https://doi.org/10.3390/pr12122630 - 22 Nov 2024
Abstract
Due to the high flow resistance of shale oil and gas, creating artificial flow channels with high conductivity in shale formation was the main challenge for the development of shale oil and gas resources. To further understand the fracture propagation mechanism in shale
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Due to the high flow resistance of shale oil and gas, creating artificial flow channels with high conductivity in shale formation was the main challenge for the development of shale oil and gas resources. To further understand the fracture propagation mechanism in shale formation, this paper proposed a global cohesive element method to simulate the hydraulic fracture propagation behavior in which natural fractures were distributed randomly, and the fracture geometry was quantitatively analyzed. From the simulation, it can be found that the horizontal stress difference was the determining factor affecting the generation of a complex fracture network. The simulation indicated that a low horizontal stress difference was beneficial for improving the stimulated volume. When the stress difference was below 5.0 MPa, numerous branch fractures were created which was the foundation of a complex fracture network. High injection rates with low-viscosity fracturing fluid were helpful for creating a complex fracture network, while high-viscosity fracturing fluid limited the fracture fluid flow into the deep formation.
Full article
(This article belongs to the Special Issue Advanced Fracturing Technology for Oil and Gas Reservoir Stimulation)
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Figure 1
Figure 1
<p>Traction-separation relationship for fracture initiation.</p> Full article ">Figure 2
<p>(<b>a</b>) Published numerical results. (<b>b</b>) Proposed model. (<b>c</b>) Injection comparison. Simulation results comparison between the published results and the proposed model.</p> Full article ">Figure 3
<p>(<b>a</b>) 8.0 m<sup>3</sup>·min<sup>−1</sup>. (<b>b</b>) 10.0 m<sup>3</sup>·min<sup>−1</sup>. (<b>c</b>) 12.0 m<sup>3</sup>·min<sup>−1</sup>. Distribution of hydraulic fracture under different injection rate.</p> Full article ">Figure 4
<p>(<b>a</b>) Comparison of the total length of fractures. (<b>b</b>) Injection pressure comparison. Changes of total fracture length and fracture pressure at different injection rate.</p> Full article ">Figure 5
<p>(<b>a</b>) 10 mPa·s. (<b>b</b>) 50 mPa·s. (<b>c</b>) 100 mPa·s. Distribution of hydraulic fracture under different fracturing fluid viscosity.</p> Full article ">Figure 6
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes of total fracture length and injection pressure under different fracturing fluid viscosity.</p> Full article ">Figure 7
<p>(<b>a</b>) 20 GPa. (<b>b</b>) 30 GPa. (<b>c</b>) 40 GPa. Distribution of hydraulic fracture under different elastic modulus.</p> Full article ">Figure 8
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes of total fracture length and injection pressure under different elastic modulus.</p> Full article ">Figure 9
<p>(<b>a</b>) 5 MPa. (<b>b</b>) 10 MPa. (<b>c</b>) 15 MPa. Distribution of hydraulic fractures under different stress differences.</p> Full article ">Figure 10
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes in total fracture length and fracture pressure under different horizontal stress differences.</p> Full article ">Figure 11
<p>(<b>a</b>) 20 m. (<b>b</b>) 40 m. (<b>c</b>) 60 m. Distribution of hydraulic fractures under different cluster spaces.</p> Full article ">Figure 12
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes in total fracture length and fracture pressure under different cluster spaces.</p> Full article ">
<p>Traction-separation relationship for fracture initiation.</p> Full article ">Figure 2
<p>(<b>a</b>) Published numerical results. (<b>b</b>) Proposed model. (<b>c</b>) Injection comparison. Simulation results comparison between the published results and the proposed model.</p> Full article ">Figure 3
<p>(<b>a</b>) 8.0 m<sup>3</sup>·min<sup>−1</sup>. (<b>b</b>) 10.0 m<sup>3</sup>·min<sup>−1</sup>. (<b>c</b>) 12.0 m<sup>3</sup>·min<sup>−1</sup>. Distribution of hydraulic fracture under different injection rate.</p> Full article ">Figure 4
<p>(<b>a</b>) Comparison of the total length of fractures. (<b>b</b>) Injection pressure comparison. Changes of total fracture length and fracture pressure at different injection rate.</p> Full article ">Figure 5
<p>(<b>a</b>) 10 mPa·s. (<b>b</b>) 50 mPa·s. (<b>c</b>) 100 mPa·s. Distribution of hydraulic fracture under different fracturing fluid viscosity.</p> Full article ">Figure 6
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes of total fracture length and injection pressure under different fracturing fluid viscosity.</p> Full article ">Figure 7
<p>(<b>a</b>) 20 GPa. (<b>b</b>) 30 GPa. (<b>c</b>) 40 GPa. Distribution of hydraulic fracture under different elastic modulus.</p> Full article ">Figure 8
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes of total fracture length and injection pressure under different elastic modulus.</p> Full article ">Figure 9
<p>(<b>a</b>) 5 MPa. (<b>b</b>) 10 MPa. (<b>c</b>) 15 MPa. Distribution of hydraulic fractures under different stress differences.</p> Full article ">Figure 10
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes in total fracture length and fracture pressure under different horizontal stress differences.</p> Full article ">Figure 11
<p>(<b>a</b>) 20 m. (<b>b</b>) 40 m. (<b>c</b>) 60 m. Distribution of hydraulic fractures under different cluster spaces.</p> Full article ">Figure 12
<p>(<b>a</b>) Comparison of the total length of cracks. (<b>b</b>) Rupture pressure comparison chart. Changes in total fracture length and fracture pressure under different cluster spaces.</p> Full article ">
Open AccessArticle
Assessment of the Influences of Numerical Models on Aerodynamic Performances in Hypersonic Nonequilibrium Flows
by
Wenqing Zhang, Zhijun Zhang and Hualin Yang
Processes 2024, 12(12), 2629; https://doi.org/10.3390/pr12122629 - 22 Nov 2024
Abstract
In this paper, the aerodynamic performances including shock wave standoff distance (SSD) and heat flux of ELECTRE vehicle at 53.3 km and 4230 m/s for several types of numerical models are investigated. The numerical models include thermal equilibrium/nonequilibrium (1T/2T) assumption, three surface boundary
[...] Read more.
In this paper, the aerodynamic performances including shock wave standoff distance (SSD) and heat flux of ELECTRE vehicle at 53.3 km and 4230 m/s for several types of numerical models are investigated. The numerical models include thermal equilibrium/nonequilibrium (1T/2T) assumption, three surface boundary conditions (no-slip/non-catalytic, slip/non-catalytic, slip/fully-catalytic), four chemical kinetic models (DK, Park, Gupta, and No Reaction (NR)) and two controlling temperatures (Ttr0.7Tve0.3, Ttr0.5Tve0.5). The results show that the chemical kinetic model significantly affects the SSD, and its value gradually decreases with the increase in chemical reaction rate. The SSD predicted by the NR model is 20.7% larger than that of the Park model. The SSD is also affected by the proportion of vibro-electronic temperature (Tve) in the controlling temperature, and the higher the proportion, the larger the SSD. Regarding the heat flux, the catalytic surface setting is crucial, where the value predicted by the fully-catalytic model is 62.2% higher than that by the non-catalytic model. As the chemical reaction rate of Gupta, DK, and Park models increases sequentially, the calculated heat flux decreases in turn. The heat flux predicted by the 2T model is lower than that by the 1T model, and the higher Tve proportion in the controlling temperature, the smaller the heat flux. The fundamental reason is that the trans-rotational convective heat flux of the 2T model is much lower than that of the 1T model, and the trans-rotational convective heat flux decreases with an increase in the Tve proportion.
Full article
(This article belongs to the Collection Modeling, Simulation and Computation on Dynamics of Complex Fluids)
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Figure 1
<p>Grid of axisymmetric model.</p> Full article ">Figure 2
<p>Trans-rotational temperatures along the axis for different grids.</p> Full article ">Figure 3
<p>Predictions and experiment data of wall heat flux.</p> Full article ">Figure 4
<p><span class="html-italic">Kn</span> of ELECTRE with 2T_Park_slip/non-catalytic model.</p> Full article ">Figure 5
<p>Flow fields of ELECTRE with <span class="html-italic">T<sub>tr</sub></span><sup>0.7</sup><span class="html-italic">T<sub>ve</sub></span><sup>0.3</sup>_Park_slip/non-catalytic model, (<b>a</b>) <span class="html-italic">T<sub>ve</sub></span>/<span class="html-italic">T<sub>tr</sub></span> and <span class="html-italic">T<sub>tr</sub></span>, (<b>b</b>) <span class="html-italic">Ma</span> and <span class="html-italic">P</span>, (<b>c</b>) <span class="html-italic">Y</span><sub>O2</sub> and <span class="html-italic">Y</span><sub>O</sub>, (<b>d</b>) <span class="html-italic">Y</span><sub>N2</sub> and <span class="html-italic">Y</span><sub>NO</sub>.</p> Full article ">Figure 6
<p>Mach numbers along axis of different numerical models, (<b>a</b>) different controlling temperatures, (<b>b</b>) different boundary conditions, (<b>c</b>) different chemical kinetic models.</p> Full article ">Figure 7
<p>Shock wave standoff distance of different numerical models.</p> Full article ">Figure 8
<p>Heat fluxes of different numerical models, (<b>a</b>) different controlling temperatures, (<b>b</b>) different boundary conditions, (<b>c</b>) different chemical kinetic models.</p> Full article ">Figure 9
<p>Stagnation point heat flux of different numerical models.</p> Full article ">Figure 10
<p>Heat flux of 1T and 2T models without reactions.</p> Full article ">Figure 11
<p>Trans-rotational and vibro-electronic convective heat fluxes.</p> Full article ">Figure 12
<p>Heat flux for fully-catalytic wall.</p> Full article ">Figure 13
<p>Forward rate coefficient of different chemical kinetic models.</p> Full article ">
<p>Grid of axisymmetric model.</p> Full article ">Figure 2
<p>Trans-rotational temperatures along the axis for different grids.</p> Full article ">Figure 3
<p>Predictions and experiment data of wall heat flux.</p> Full article ">Figure 4
<p><span class="html-italic">Kn</span> of ELECTRE with 2T_Park_slip/non-catalytic model.</p> Full article ">Figure 5
<p>Flow fields of ELECTRE with <span class="html-italic">T<sub>tr</sub></span><sup>0.7</sup><span class="html-italic">T<sub>ve</sub></span><sup>0.3</sup>_Park_slip/non-catalytic model, (<b>a</b>) <span class="html-italic">T<sub>ve</sub></span>/<span class="html-italic">T<sub>tr</sub></span> and <span class="html-italic">T<sub>tr</sub></span>, (<b>b</b>) <span class="html-italic">Ma</span> and <span class="html-italic">P</span>, (<b>c</b>) <span class="html-italic">Y</span><sub>O2</sub> and <span class="html-italic">Y</span><sub>O</sub>, (<b>d</b>) <span class="html-italic">Y</span><sub>N2</sub> and <span class="html-italic">Y</span><sub>NO</sub>.</p> Full article ">Figure 6
<p>Mach numbers along axis of different numerical models, (<b>a</b>) different controlling temperatures, (<b>b</b>) different boundary conditions, (<b>c</b>) different chemical kinetic models.</p> Full article ">Figure 7
<p>Shock wave standoff distance of different numerical models.</p> Full article ">Figure 8
<p>Heat fluxes of different numerical models, (<b>a</b>) different controlling temperatures, (<b>b</b>) different boundary conditions, (<b>c</b>) different chemical kinetic models.</p> Full article ">Figure 9
<p>Stagnation point heat flux of different numerical models.</p> Full article ">Figure 10
<p>Heat flux of 1T and 2T models without reactions.</p> Full article ">Figure 11
<p>Trans-rotational and vibro-electronic convective heat fluxes.</p> Full article ">Figure 12
<p>Heat flux for fully-catalytic wall.</p> Full article ">Figure 13
<p>Forward rate coefficient of different chemical kinetic models.</p> Full article ">
Open AccessArticle
Simulation and Experiment on Hull Lower Welding Deformation Using Heat Source Shape
by
Chung-Woo Lee, Suseong Woo and Jisun Kim
Processes 2024, 12(12), 2628; https://doi.org/10.3390/pr12122628 - 22 Nov 2024
Abstract
To effectively use aluminum, which is inherently weak under heat, as a material for hull construction, it is crucial to precisely predict the thermal deformation in the weld zone. Most studies employing finite element (FE) methods to predict thermal deformation due to welding
[...] Read more.
To effectively use aluminum, which is inherently weak under heat, as a material for hull construction, it is crucial to precisely predict the thermal deformation in the weld zone. Most studies employing finite element (FE) methods to predict thermal deformation due to welding typically use estimated heat source conditions based on the results of the weld. However, these estimated values can differ significantly from the actual welding conditions. In this study, we investigated whether using the actual shape of the heat source, rather than an estimated value, can serve as a reliable condition for analysis in predicting thermal deformation. This prediction is essential for minimizing deformation in the fillet welds of an aluminum hull. To compare deformation outcomes, Al 5083, commonly used in hull construction, was selected as the base material. The thermal deformation of aluminum hull fillet welds, welded using the Cold Metal Transfer (CMT) welding method, which reduces heat input, was measured. The simulation results demonstrated similar deformation trends, with discrepancies ranging from a minimum of 0.02 mm to a maximum of 1.4 mm when using actual welding conditions and heat source shapes. The results of this study confirm that the actual heat source shape can be utilized as a reliable condition for predicting thermal deformation in aluminum hull welds. The aim is to contribute to the improvement of aluminum hull manufacturing quality by providing essential data for establishing welding conditions and minimizing deformation.
Full article
(This article belongs to the Special Issue Features, Reviews and Perspectives for the 10th Anniversary of Processes)
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<p>Welding equipment configuration and welding location used in the experiment.</p> Full article ">Figure 2
<p>Welding jig and deformation measurement locations used in the experiment: (<b>a</b>) welding jig; (<b>b</b>) weld deformation measurement locations.</p> Full article ">Figure 3
<p>Mesh in FEM model.</p> Full article ">Figure 4
<p>Properties of Al 5083 as a function of temperature: (<b>a</b>) thermal conductivity; (<b>b</b>) expansion coefficient; (<b>c</b>) specific heat; (<b>d</b>) latent heat.</p> Full article ">Figure 5
<p>Bead dimensioning locations and welding results: (<b>a</b>) bead dimensioning locations; (<b>b</b>) fillet welding experiment results.</p> Full article ">Figure 6
<p>Bead geometry dimensioning results as a function of weld variables: (<b>a</b>) throat length; (<b>b</b>) penetration depth; (<b>c</b>) contact angle.</p> Full article ">Figure 7
<p>Heat source geometry of the weld bead.</p> Full article ">Figure 8
<p>Heat distribution of Goldak model. Reproduced with permission from [<a href="#B39-processes-12-02628" class="html-bibr">39</a>].</p> Full article ">Figure 9
<p>Simulation results by arc efficiency condition: (<b>a</b>) arc efficiency 80%; (<b>b</b>) 85%; (<b>c</b>) 90%.</p> Full article ">Figure 10
<p>Comparison of bead geometry results at 90% arc efficiency.</p> Full article ">Figure 11
<p>Deformation prediction results.</p> Full article ">Figure 12
<p>Comparison of simulation and experimental results: (<b>a</b>) line 1, (<b>b</b>) line 2, (<b>c</b>) line 3, (<b>d</b>) line 4, (<b>e</b>) line 5.</p> Full article ">Figure 13
<p>Standard deviation of measured and simulation deformation values.</p> Full article ">Figure 14
<p>Schematic diagram of deformation trend of fillet weld.</p> Full article ">
<p>Welding equipment configuration and welding location used in the experiment.</p> Full article ">Figure 2
<p>Welding jig and deformation measurement locations used in the experiment: (<b>a</b>) welding jig; (<b>b</b>) weld deformation measurement locations.</p> Full article ">Figure 3
<p>Mesh in FEM model.</p> Full article ">Figure 4
<p>Properties of Al 5083 as a function of temperature: (<b>a</b>) thermal conductivity; (<b>b</b>) expansion coefficient; (<b>c</b>) specific heat; (<b>d</b>) latent heat.</p> Full article ">Figure 5
<p>Bead dimensioning locations and welding results: (<b>a</b>) bead dimensioning locations; (<b>b</b>) fillet welding experiment results.</p> Full article ">Figure 6
<p>Bead geometry dimensioning results as a function of weld variables: (<b>a</b>) throat length; (<b>b</b>) penetration depth; (<b>c</b>) contact angle.</p> Full article ">Figure 7
<p>Heat source geometry of the weld bead.</p> Full article ">Figure 8
<p>Heat distribution of Goldak model. Reproduced with permission from [<a href="#B39-processes-12-02628" class="html-bibr">39</a>].</p> Full article ">Figure 9
<p>Simulation results by arc efficiency condition: (<b>a</b>) arc efficiency 80%; (<b>b</b>) 85%; (<b>c</b>) 90%.</p> Full article ">Figure 10
<p>Comparison of bead geometry results at 90% arc efficiency.</p> Full article ">Figure 11
<p>Deformation prediction results.</p> Full article ">Figure 12
<p>Comparison of simulation and experimental results: (<b>a</b>) line 1, (<b>b</b>) line 2, (<b>c</b>) line 3, (<b>d</b>) line 4, (<b>e</b>) line 5.</p> Full article ">Figure 13
<p>Standard deviation of measured and simulation deformation values.</p> Full article ">Figure 14
<p>Schematic diagram of deformation trend of fillet weld.</p> Full article ">
Open AccessReview
Suspended Particles in Water and Energetically Sustainable Solutions of Their Removal—A Review
by
Štěpán Zezulka, Blahoslav Maršálek, Eliška Maršálková, Klára Odehnalová, Marcela Pavlíková and Adéla Lamaczová
Processes 2024, 12(12), 2627; https://doi.org/10.3390/pr12122627 - 22 Nov 2024
Abstract
Solid particles (SP) suspended in water represent a common contamination that degrades the water quality, not only in drinking water sources. Particles differ in size, nature, and related features like surface charge. Thus, various methods can be utilized for their removal—physical approaches including
[...] Read more.
Solid particles (SP) suspended in water represent a common contamination that degrades the water quality, not only in drinking water sources. Particles differ in size, nature, and related features like surface charge. Thus, various methods can be utilized for their removal—physical approaches including settling or filtration, chemical coagulation/flocculation, biological microbial degradation, and others. This paper aims to summarize currently available methods for SP removal with special attention devoted to alternative, cost-effective, sustainable, and eco-friendly approaches with low energetic demands where the power of renewable energy sources can be utilized. Besides SP properties, the selection of the proper method (or a sequence of methods) for their separation also depends on the purpose of water treatment. Drinking water production demands technologies with immediate effect and high throughputs, like conventional filtration and coagulation/flocculation (electro- or chemical with alternative coagulant/flocculant agents) or some hybrid approaches to ensure quick and cost-effective decontamination. Such technologies usually imply heavy machinery with high electricity consumption, but current progress allows the construction of smaller facilities powered by solar or wind power plant systems. On the other hand, water decontamination in rivers or ponds can include slower processes based on phytoremediation, being long-term sustainable with minimal energy and cost investments.
Full article
(This article belongs to the Special Issue Energy and Water Treatment Processes)
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<p>Illustration of the number of scientific works focused on suspended solid particles in water and related topics according to the Core Collection database (September 2024, Web of Science, Clarivate).</p> Full article ">Figure 2
<p>Example of suspended solids from sediment; sand (S) and clay (C) particles on a scanning electron microscopy photograph.</p> Full article ">Figure 3
<p>General scheme of coagulation and flocculation processes using coagulant and flocculant agents to interact with suspended particles and other impurities. In alternative approaches, chemical coagulants and flocculants can be replaced by natural products (starch, ash, etc.) or produced in situ in an electrochemical way from electrode material.</p> Full article ">Figure 4
<p>Illustration of approaches based on phytoremediation, utilizing constructed wetlands, riparian vegetation stripes, and vegetated floating islands. Submersed parts of plants (especially roots or stems) can provide a place for microbial biofilm formation.</p> Full article ">
<p>Illustration of the number of scientific works focused on suspended solid particles in water and related topics according to the Core Collection database (September 2024, Web of Science, Clarivate).</p> Full article ">Figure 2
<p>Example of suspended solids from sediment; sand (S) and clay (C) particles on a scanning electron microscopy photograph.</p> Full article ">Figure 3
<p>General scheme of coagulation and flocculation processes using coagulant and flocculant agents to interact with suspended particles and other impurities. In alternative approaches, chemical coagulants and flocculants can be replaced by natural products (starch, ash, etc.) or produced in situ in an electrochemical way from electrode material.</p> Full article ">Figure 4
<p>Illustration of approaches based on phytoremediation, utilizing constructed wetlands, riparian vegetation stripes, and vegetated floating islands. Submersed parts of plants (especially roots or stems) can provide a place for microbial biofilm formation.</p> Full article ">
Open AccessArticle
Optimization of CO2 Capture Using a New Aqueous Hybrid Solvent (MDEA-[TBPA][TFA]) with a Low Heat Capacity: Integration of COSMO-RS and RSM Approaches
by
Fairuz Liyana Mohd Rasdi, Revathi Jeyaseelan, Mohd Faisal Taha and Mohamad Amirul Ashraf Mohd Razip
Processes 2024, 12(12), 2626; https://doi.org/10.3390/pr12122626 - 22 Nov 2024
Abstract
This study aims to evaluate the performance of a new hybrid solvent, comprising aqueous MDEA and tetrabutylphosphonium trifluoroacetate ([TBP][TFA]), for CO2 capture and to optimize its CO2 absorption efficiency. First, this study focused on predicting the thermodynamic properties of aqueous MDEAs
[...] Read more.
This study aims to evaluate the performance of a new hybrid solvent, comprising aqueous MDEA and tetrabutylphosphonium trifluoroacetate ([TBP][TFA]), for CO2 capture and to optimize its CO2 absorption efficiency. First, this study focused on predicting the thermodynamic properties of aqueous MDEAs and [TBP][TFA] and their interaction energy with CO2 using COSMO-RS. Based on the prediction, it aligns with the principle that CO2 solubility in the MDEA-[TBP][TFA] hybrid solvent decreases as the Henry’s Law constant increases, with the interactions primarily governed by van der Waals forces and hydrogen bonding. The aqueous MDEA-[TBP][TFA] hybrid solvent was prepared in two steps: synthesizing and blending [TBP][TFA] with aqueous MDEAs. The formation and purity of [TBP][TFA] were confirmed through NMR, FT-IR, and Karl Fischer. The heat capacity of the hybrid solvents was lower than their aqueous MDEA solutions. The performance and optimization of CO2 capture were studied using RSM-FC-CCD design, with the optimal value obtained at 50 wt.% MDEA, 20 wt.% [TBP][TFA], 30 °C, and 30 bar (12.14 mol/kg), aligning with COSMO-RS predictions. A 26% reduction in the heat capacity was achieved with the optimal ratio (wt.%) of the hybrid solvent. These findings suggest that the aqueous MDEA-[TBP][TFA] hybrid solvent is a promising alternative for CO2 capture, providing a high removal capacity and lower heat capacity for more efficient regeneration compared to commercial aqueous MDEA solutions.
Full article
(This article belongs to the Section Chemical Processes and Systems)
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Figure 1
<p>The schematic diagram of the CO<sub>2</sub> absorption system.</p> Full article ">Figure 2
<p>Solubility of CO<sub>2</sub> in ionic liquid [TBP][TFA], aqueous MDEA (10, 30, and 50 wt.%) at a CO<sub>2</sub> partial pressure range of 2–20 bar at 298.15 K.</p> Full article ">Figure 3
<p>The comparison of Henry’s Law constant value for ionic liquid [TBP][TFA] and aqueous MDEA (10, 30, and 50 wt.%) at 298.15 K.</p> Full article ">Figure 4
<p>Sigma profiles of aqueous MDEA, [TBP][TFA], and CO<sub>2</sub>.</p> Full article ">Figure 5
<p>Sigma potentials of aqueous MDEA, [TBP][TFA], and CO<sub>2</sub>.</p> Full article ">Figure 6
<p>Preparative scheme for [TBP][TFA] ionic liquid.</p> Full article ">Figure 7
<p>(<b>a</b>) <sup>1</sup>H NMR spectrum of [TBP][TFA] and (<b>b</b>) <sup>13</sup>C NMR spectrum of [TBP][TFA] ionic liquid. The letters correspond to their respective peaks, with each peak labeled using the same alphabet.</p> Full article ">Figure 8
<p>FT−IR spectrum of [TBP][TFA] ionic liquid.</p> Full article ">Figure 9
<p>Densities of (<b>a</b>) 10 wt.% aqueous MDEA–[TBP][TFA], (<b>b</b>) 30 wt.% aqueous MDEA–[TBP][TFA], and (<b>c</b>) 50 wt.% aqueous MDEA–[TBP][TFA] containing different [TBP][TFA] concentrations at the temperature range of 20–80 °C.</p> Full article ">Figure 10
<p>Viscosities of (<b>a</b>) 10 wt.% aqueous MDEA–[TBP][TFA], (<b>b</b>) 30 wt.% aqueous MDEA– [TBP][TFA], and (<b>c</b>) 50 wt.% aqueous MDEA–[TBP][TFA] containing different [TBP][TFA] concentrations at the temperature range of 20–80°C.</p> Full article ">Figure 11
<p>Three-dimensional RSM plots illustrating the impact of various parameters on the CO<sub>2</sub> removal capacity: (<b>a</b>) MDEA (wt.%) vs. IL (wt.%); (<b>b</b>) temperature (°C) vs. pressure (bar); (<b>c</b>) MDEA (wt.%) vs. pressure (bar); (<b>d</b>) IL (wt.%) vs. pressure (bar); (<b>e</b>) IL (wt.%) vs. temperature (°C); (<b>f</b>) MDEA (wt.%) vs. temperature (°C). The colors in the 3D RSM plot represent the response values, with colors like blue and green indicating lower values and red indicating higher values. The red and yellow dots in the 3D RSM plot represent specific experimental runs, highlighting critical and intermediate response values.</p> Full article ">Figure 11 Cont.
<p>Three-dimensional RSM plots illustrating the impact of various parameters on the CO<sub>2</sub> removal capacity: (<b>a</b>) MDEA (wt.%) vs. IL (wt.%); (<b>b</b>) temperature (°C) vs. pressure (bar); (<b>c</b>) MDEA (wt.%) vs. pressure (bar); (<b>d</b>) IL (wt.%) vs. pressure (bar); (<b>e</b>) IL (wt.%) vs. temperature (°C); (<b>f</b>) MDEA (wt.%) vs. temperature (°C). The colors in the 3D RSM plot represent the response values, with colors like blue and green indicating lower values and red indicating higher values. The red and yellow dots in the 3D RSM plot represent specific experimental runs, highlighting critical and intermediate response values.</p> Full article ">Figure 12
<p>Comparison of CO<sub>2</sub> removal capacity and heat capacity at optimum temperatures and pressures.</p> Full article ">
<p>The schematic diagram of the CO<sub>2</sub> absorption system.</p> Full article ">Figure 2
<p>Solubility of CO<sub>2</sub> in ionic liquid [TBP][TFA], aqueous MDEA (10, 30, and 50 wt.%) at a CO<sub>2</sub> partial pressure range of 2–20 bar at 298.15 K.</p> Full article ">Figure 3
<p>The comparison of Henry’s Law constant value for ionic liquid [TBP][TFA] and aqueous MDEA (10, 30, and 50 wt.%) at 298.15 K.</p> Full article ">Figure 4
<p>Sigma profiles of aqueous MDEA, [TBP][TFA], and CO<sub>2</sub>.</p> Full article ">Figure 5
<p>Sigma potentials of aqueous MDEA, [TBP][TFA], and CO<sub>2</sub>.</p> Full article ">Figure 6
<p>Preparative scheme for [TBP][TFA] ionic liquid.</p> Full article ">Figure 7
<p>(<b>a</b>) <sup>1</sup>H NMR spectrum of [TBP][TFA] and (<b>b</b>) <sup>13</sup>C NMR spectrum of [TBP][TFA] ionic liquid. The letters correspond to their respective peaks, with each peak labeled using the same alphabet.</p> Full article ">Figure 8
<p>FT−IR spectrum of [TBP][TFA] ionic liquid.</p> Full article ">Figure 9
<p>Densities of (<b>a</b>) 10 wt.% aqueous MDEA–[TBP][TFA], (<b>b</b>) 30 wt.% aqueous MDEA–[TBP][TFA], and (<b>c</b>) 50 wt.% aqueous MDEA–[TBP][TFA] containing different [TBP][TFA] concentrations at the temperature range of 20–80 °C.</p> Full article ">Figure 10
<p>Viscosities of (<b>a</b>) 10 wt.% aqueous MDEA–[TBP][TFA], (<b>b</b>) 30 wt.% aqueous MDEA– [TBP][TFA], and (<b>c</b>) 50 wt.% aqueous MDEA–[TBP][TFA] containing different [TBP][TFA] concentrations at the temperature range of 20–80°C.</p> Full article ">Figure 11
<p>Three-dimensional RSM plots illustrating the impact of various parameters on the CO<sub>2</sub> removal capacity: (<b>a</b>) MDEA (wt.%) vs. IL (wt.%); (<b>b</b>) temperature (°C) vs. pressure (bar); (<b>c</b>) MDEA (wt.%) vs. pressure (bar); (<b>d</b>) IL (wt.%) vs. pressure (bar); (<b>e</b>) IL (wt.%) vs. temperature (°C); (<b>f</b>) MDEA (wt.%) vs. temperature (°C). The colors in the 3D RSM plot represent the response values, with colors like blue and green indicating lower values and red indicating higher values. The red and yellow dots in the 3D RSM plot represent specific experimental runs, highlighting critical and intermediate response values.</p> Full article ">Figure 11 Cont.
<p>Three-dimensional RSM plots illustrating the impact of various parameters on the CO<sub>2</sub> removal capacity: (<b>a</b>) MDEA (wt.%) vs. IL (wt.%); (<b>b</b>) temperature (°C) vs. pressure (bar); (<b>c</b>) MDEA (wt.%) vs. pressure (bar); (<b>d</b>) IL (wt.%) vs. pressure (bar); (<b>e</b>) IL (wt.%) vs. temperature (°C); (<b>f</b>) MDEA (wt.%) vs. temperature (°C). The colors in the 3D RSM plot represent the response values, with colors like blue and green indicating lower values and red indicating higher values. The red and yellow dots in the 3D RSM plot represent specific experimental runs, highlighting critical and intermediate response values.</p> Full article ">Figure 12
<p>Comparison of CO<sub>2</sub> removal capacity and heat capacity at optimum temperatures and pressures.</p> Full article ">
Open AccessArticle
The Use of a Trichoderma reesei Culture for the Hydrolysis of Wheat Straw to Obtain Bioethanol
by
Maria Ciobanu, Carmen Otilia Rusănescu and Raluca Lucia Dinculoiu
Processes 2024, 12(12), 2625; https://doi.org/10.3390/pr12122625 - 22 Nov 2024
Abstract
To reduce environmental pollution, a renewable source of energy that we may utilize is bioethanol obtained from wheat straw. Wheat straw was ground to 40–50 mm in size and heat-treated with high-pressure steam to release lignocelluloses, making them accessible to enzymes during saccharification.
[...] Read more.
To reduce environmental pollution, a renewable source of energy that we may utilize is bioethanol obtained from wheat straw. Wheat straw was ground to 40–50 mm in size and heat-treated with high-pressure steam to release lignocelluloses, making them accessible to enzymes during saccharification. Through mechanical pretreatment, a substrate was obtained, which contains toxic components in concentrations that do not diminish the performance of the enzymes in the enzymatic hydrolysis phase. Through the thermal pretreatment of wheat straw, its acidity was improved, influencing the amounts of glucose, xylose, and other components emitted. Following enzymatic hydrolysis, very small concentrations of sugars were released. In order to increase the efficiency of the transformation of sugars into ethanol during the fermentation process, a strain of yeast, Trichoderma reesei multiplied in the laboratory, was added, under the conditions of temperature—28 degrees and stirring—800 rpm. Trichoderma reesei penetrated the wheat straw substrate, facilitating the subsequent hydrolysis process. The improved biodegradation of the pretreated straws was highlighted by the electron microscopy analysis.
Full article
(This article belongs to the Special Issue Bioethanol Production: Process, Technology and Sustainable Industrial Applications)
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<p>The process of obtaining bioethanol from lignocellulosic biomass (adapted from [<a href="#B14-processes-12-02625" class="html-bibr">14</a>]).</p> Full article ">Figure 2
<p>Map of straw supply localities.</p> Full article ">Figure 3
<p>Checking the quality of straw bales.</p> Full article ">Figure 4
<p>Knives for cutting wheat straw.</p> Full article ">Figure 5
<p>Sectioned straw sample.</p> Full article ">Figure 6
<p>Sample substrate.</p> Full article ">Figure 7
<p>Hydrolysate obtained after enzymatic hydrolysis.</p> Full article ">Figure 8
<p><span class="html-italic">Trichoderma reesei</span> multiplied in the laboratory.</p> Full article ">Figure 9
<p><span class="html-italic">Trichoderma reesei</span> transferred into production.</p> Full article ">Figure 10
<p><span class="html-italic">Trichoderma reesei</span> in the last fermentation reactor.</p> Full article ">Figure 11
<p>Scanning electron microscope (SEM) images (×1.00 kx magnification) indicating the inaccessible and packed structure of untreated and biotreated wheat straw. (<b>a</b>) Untreated wheat straw; (<b>b</b>) biotreated wheat straw (adapted from [<a href="#B2-processes-12-02625" class="html-bibr">2</a>]).</p> Full article ">
<p>The process of obtaining bioethanol from lignocellulosic biomass (adapted from [<a href="#B14-processes-12-02625" class="html-bibr">14</a>]).</p> Full article ">Figure 2
<p>Map of straw supply localities.</p> Full article ">Figure 3
<p>Checking the quality of straw bales.</p> Full article ">Figure 4
<p>Knives for cutting wheat straw.</p> Full article ">Figure 5
<p>Sectioned straw sample.</p> Full article ">Figure 6
<p>Sample substrate.</p> Full article ">Figure 7
<p>Hydrolysate obtained after enzymatic hydrolysis.</p> Full article ">Figure 8
<p><span class="html-italic">Trichoderma reesei</span> multiplied in the laboratory.</p> Full article ">Figure 9
<p><span class="html-italic">Trichoderma reesei</span> transferred into production.</p> Full article ">Figure 10
<p><span class="html-italic">Trichoderma reesei</span> in the last fermentation reactor.</p> Full article ">Figure 11
<p>Scanning electron microscope (SEM) images (×1.00 kx magnification) indicating the inaccessible and packed structure of untreated and biotreated wheat straw. (<b>a</b>) Untreated wheat straw; (<b>b</b>) biotreated wheat straw (adapted from [<a href="#B2-processes-12-02625" class="html-bibr">2</a>]).</p> Full article ">
Open AccessArticle
Fluid Phase Behavior of the Licuri (Syagrus coronata) Fatty Acid Ethyl Ester + Glycerol + Ethanol Mixtures at Different Temperatures—Experimental and Thermodynamic Modeling
by
Iza Estevam Pedrosa Toledo, Dayana de Gusmão Coêlho, Lucas Meili, Carlos Toshiyuki Hiranobe, Marcos Lúcio Corazza, Pedro Arce, Erivaldo Antônio da Silva, Sandra Helena Vieira de Carvalho, Renivaldo José dos Santos, João Inácio Soletti and Leandro Ferreira-Pinto
Processes 2024, 12(12), 2624; https://doi.org/10.3390/pr12122624 - 22 Nov 2024
Abstract
This study provides experimental insights into the liquid–liquid equilibrium (LLE) of a system consisting of fatty acid ethyl ester (FAEE) derived from licuri oil, glycerol, and ethanol, evaluated at various temperatures and standard atmospheric pressures. FAEE was synthesized through transesterification of licuri oil
[...] Read more.
This study provides experimental insights into the liquid–liquid equilibrium (LLE) of a system consisting of fatty acid ethyl ester (FAEE) derived from licuri oil, glycerol, and ethanol, evaluated at various temperatures and standard atmospheric pressures. FAEE was synthesized through transesterification of licuri oil using NaOH as a catalyst. The liquid phase compositions were assessed via titration, and the results were consistent with the solubility curves and overall compositions. Data reliability was confirmed using Hand and Othmer-Tobias correlations, with a determination coefficient (R2) of 1, validating the dependability of the results. The NRTL model was employed to correlate the LLE data, yielding a root-mean-square deviation (RMSD) of approximately 1.20%, signifying a strong correlation with experimental uncertainties. The selectivity (S) and distribution (D) parameters indicated the efficacy of glycerol in the system, with S values exceeding 1 under all conditions tested. This investigation is crucial for biodiesel production, highlighting the potential of licuri oil as a renewable feedstock and the importance of phase equilibrium studies in the separation processes of biodiesel production products.
Full article
(This article belongs to the Special Issue Studies on Chemical Processes Thermodynamics)
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<p>Schematic of the equilibrium cell setup: (1) equilibrium cell; (2) magnetic stirrer; and (3) Thermostatic Bath.</p> Full article ">Figure 2
<p>Graphical representation of (<b>A</b>) separation factor and (<b>B</b>) distribution coefficient for the ternary system {FAEE licuri (1) + glycerol (2) + ethanol (3)} at two temperatures (■, 303.15 K and ●, 318.15 K).</p> Full article ">Figure 3
<p>Experimental data and NRTL model predictions for the ternary system {FAEE licuri (1)/glycerol (2)/ethanol (3)} at (<b>A</b>) 303.15 K and (<b>B</b>) 318.15 K. Experimental (●, overall composition; <span class="html-fig-inline" id="processes-12-02624-i001"><img alt="Processes 12 02624 i001" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i001.png"/></span>, tie line; and ○, binodal points) and NRTL model (<span class="html-fig-inline" id="processes-12-02624-i002"><img alt="Processes 12 02624 i002" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i002.png"/></span>, tie line; and <span class="html-fig-inline" id="processes-12-02624-i003"><img alt="Processes 12 02624 i003" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i003.png"/></span>, binodal line).</p> Full article ">
<p>Schematic of the equilibrium cell setup: (1) equilibrium cell; (2) magnetic stirrer; and (3) Thermostatic Bath.</p> Full article ">Figure 2
<p>Graphical representation of (<b>A</b>) separation factor and (<b>B</b>) distribution coefficient for the ternary system {FAEE licuri (1) + glycerol (2) + ethanol (3)} at two temperatures (■, 303.15 K and ●, 318.15 K).</p> Full article ">Figure 3
<p>Experimental data and NRTL model predictions for the ternary system {FAEE licuri (1)/glycerol (2)/ethanol (3)} at (<b>A</b>) 303.15 K and (<b>B</b>) 318.15 K. Experimental (●, overall composition; <span class="html-fig-inline" id="processes-12-02624-i001"><img alt="Processes 12 02624 i001" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i001.png"/></span>, tie line; and ○, binodal points) and NRTL model (<span class="html-fig-inline" id="processes-12-02624-i002"><img alt="Processes 12 02624 i002" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i002.png"/></span>, tie line; and <span class="html-fig-inline" id="processes-12-02624-i003"><img alt="Processes 12 02624 i003" src="/processes/processes-12-02624/article_deploy/html/images/processes-12-02624-i003.png"/></span>, binodal line).</p> Full article ">
Open AccessArticle
Effects of Surface Treatment on Adhesive Performance of Composite-to-Composite and Composite-to-Metal Joints
by
Nikhil Paranjpe, Md. Nizam Uddin, Akm Samsur Rahman and Ramazan Asmatulu
Processes 2024, 12(12), 2623; https://doi.org/10.3390/pr12122623 - 21 Nov 2024
Abstract
This study deals with the long-running challenge of joining similar and dissimilar materials using composite-to-composite and composite-to-metal joints. This research was conducted to evaluate the effects of surface morphology and surface treatments on the mechanical performance of adhesively bonded joints used for the
[...] Read more.
This study deals with the long-running challenge of joining similar and dissimilar materials using composite-to-composite and composite-to-metal joints. This research was conducted to evaluate the effects of surface morphology and surface treatments on the mechanical performance of adhesively bonded joints used for the aircraft industry. A two-segment, commercially available, toughened epoxy was chosen as the adhesive. Unidirectional carbon fiber prepreg and aluminum 2021-T3 alloys were chosen for the composite and metal panels, respectively. Surface treatment of the metal included corrosion elimination followed by a passive surface coating of Alodine®. A combination of surface treatment methods was used for the composite and metal specimens, including detergent cleaning, plasma exposure, and sandblasting. The shear strength of the single-lap adhesive joint was evaluated according to the ASTM D1002. Ultraviolet (UV) and plasma exposure effects were studied by measuring the water contact angles. The test results showed that the aluminum adherent treated with sandblasting, detergent, and UV irradiation resulted in the strongest adhesive bonding of the composite-to-composite panels, while the composite-to-metal sample cleaned only with detergent resulted in the least bonding strength. The failure strain of the composite-to-composite bonding was reduced by approximately 50% with only sandblasting. However, extended treatment did not introduce additional brittleness in the adhesive joint. The bonding strength of the composite-to-composite panel improved by approximately 35% with plasma treatment alone because of the better surface functionalization and bonding strength. In the composite-to-aluminum bonding process, exposing the aluminum surface to UV resulted in 30% more joint strength compared to the Alodine® coating, which suggests the origination of higher orders of magnitude of covalent groups from the surface. A comparison with published results found that the joint strengths in both similar and dissimilar specimens are higher than most other results. Detailed observations and surface analysis studies showed that the composite-to-composite bonding mainly failed due to adhesive and cohesive failures; however, failure of the composite-to-aluminum bonding was heterogeneous, where adhesive failure occurred on the aluminum side and substrate failure occurred on the composite side.
Full article
(This article belongs to the Special Issue Development and Characterization of Advanced Polymer Nanocomposites)
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Show Figures
Figure 1
Figure 1
<p>Schematic for a plasma treatment process [<a href="#B24-processes-12-02623" class="html-bibr">24</a>].</p> Full article ">Figure 2
<p>Composite-to-composite and composite-to-aluminum single-lap joint process.</p> Full article ">Figure 3
<p>Effect of plasma treatment on wettability of composite surfaces before and after sandpapering.</p> Full article ">Figure 4
<p>Effects of various surface and plasma treatments on wettability of aluminum alloy surface.</p> Full article ">Figure 5
<p>Stress–strain diagram of composite-to-composite adhesive bonding with sandpaper at various plasma treatment times.</p> Full article ">Figure 6
<p>Joint strength of plasma-treated composite-to-composite surface with different surface preparations (CT—detergent cleaned, ST—sand treatment).</p> Full article ">Figure 7
<p>Joint strength of composite-to-aluminum surface with different surface preparations. (CT—detergent cleaned, ST—sand treatment, PT—plasma treatment, Coat—Alodine<sup>®</sup>-coated, UV—UV treatment).</p> Full article ">Figure 8
<p>Lap shear fracture surfaces: (<b>a</b>,<b>b</b>) composite-to-composite joints and (<b>c</b>,<b>d</b>) composite-to-aluminum joints.</p> Full article ">Figure 9
<p>Demonstration of lap joint failure modes under axial tensile load: (<b>a</b>–<b>c</b>) composite-to-aluminum and (<b>d</b>,<b>e</b>) composite-to-composite [<a href="#B43-processes-12-02623" class="html-bibr">43</a>,<a href="#B44-processes-12-02623" class="html-bibr">44</a>].</p> Full article ">
<p>Schematic for a plasma treatment process [<a href="#B24-processes-12-02623" class="html-bibr">24</a>].</p> Full article ">Figure 2
<p>Composite-to-composite and composite-to-aluminum single-lap joint process.</p> Full article ">Figure 3
<p>Effect of plasma treatment on wettability of composite surfaces before and after sandpapering.</p> Full article ">Figure 4
<p>Effects of various surface and plasma treatments on wettability of aluminum alloy surface.</p> Full article ">Figure 5
<p>Stress–strain diagram of composite-to-composite adhesive bonding with sandpaper at various plasma treatment times.</p> Full article ">Figure 6
<p>Joint strength of plasma-treated composite-to-composite surface with different surface preparations (CT—detergent cleaned, ST—sand treatment).</p> Full article ">Figure 7
<p>Joint strength of composite-to-aluminum surface with different surface preparations. (CT—detergent cleaned, ST—sand treatment, PT—plasma treatment, Coat—Alodine<sup>®</sup>-coated, UV—UV treatment).</p> Full article ">Figure 8
<p>Lap shear fracture surfaces: (<b>a</b>,<b>b</b>) composite-to-composite joints and (<b>c</b>,<b>d</b>) composite-to-aluminum joints.</p> Full article ">Figure 9
<p>Demonstration of lap joint failure modes under axial tensile load: (<b>a</b>–<b>c</b>) composite-to-aluminum and (<b>d</b>,<b>e</b>) composite-to-composite [<a href="#B43-processes-12-02623" class="html-bibr">43</a>,<a href="#B44-processes-12-02623" class="html-bibr">44</a>].</p> Full article ">
Open AccessArticle
Study on Real-Time Detection of Lightweight Tomato Plant Height Under Improved YOLOv5 and Visual Features
by
Ling Leng, Lin Wang, Jinhong Lv, Pengan Xie, Chao Zeng, Weibin Wu and Chaoyan Fan
Processes 2024, 12(12), 2622; https://doi.org/10.3390/pr12122622 - 21 Nov 2024
Abstract
Tomato cultivation is relatively dense, and the main stem is easily submerged in a background environment with small color difference. The semi-enclosed planting space and fast growth cycle are both limitations that cannot be ignored in detection technology. The accuracy and real-time performance
[...] Read more.
Tomato cultivation is relatively dense, and the main stem is easily submerged in a background environment with small color difference. The semi-enclosed planting space and fast growth cycle are both limitations that cannot be ignored in detection technology. The accuracy and real-time performance of plant height detection are of great practical significance. To this end, we are committed to improving YOLOv5 and proposing a lightweight real-time detection method for plant height by combining visual features of tomato main stems. Here, we improved the backbone, neck, head, and activation functions of YOLOv5, using CSP dark net53-s as the backbone structure and introducing a focus structure to reduce the number of GE modules. We replaced all CSP2_X structures in neck and head with GE modules, embedded interactive multi-head attention, and replaced YOLOv5’s framework function and attention activation function. We defined visual features such as the color of the main stem of tomato plants in the preprocessed image; input improved YOLOv5; and completed plant height detection through effective feature map fusion, main stem framing, and scale conversion. The experimental results show that the linear deviation between the plant height detection value and the actual value of the proposed method is always less than 3 cm, and the detection FPS can reach up to 67 frames per second, with superior timeliness, which can effectively achieve lightweight real-time detection.
Full article
(This article belongs to the Special Issue Intelligent Monitoring and Fault Diagnosis of Complex Industrial Processes or Equipment)
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Show Figures
Figure 1
Figure 1
<p>Improved YOLOv5 schematic.</p> Full article ">Figure 2
<p>Image acquisition and plant height detection site map.</p> Full article ">Figure 3
<p>Tomato image.</p> Full article ">Figure 4
<p>Schematic diagram of the improved YOLOv5 ablation experiment. (<b>a</b>) Parameter and computational quantities; (<b>b</b>) pixel granularity accuracy.</p> Full article ">Figure 5
<p>Schematic diagram of plant height detection performance of different methods. (<b>a</b>) Linearity deviation of the measured value; (<b>b</b>) FPS value.</p> Full article ">Figure 6
<p>Performance results of tomato plant height detection by different comparison methods. (<b>a</b>) Linearity deviation of the measured value; (<b>b</b>) FPS value.</p> Full article ">
<p>Improved YOLOv5 schematic.</p> Full article ">Figure 2
<p>Image acquisition and plant height detection site map.</p> Full article ">Figure 3
<p>Tomato image.</p> Full article ">Figure 4
<p>Schematic diagram of the improved YOLOv5 ablation experiment. (<b>a</b>) Parameter and computational quantities; (<b>b</b>) pixel granularity accuracy.</p> Full article ">Figure 5
<p>Schematic diagram of plant height detection performance of different methods. (<b>a</b>) Linearity deviation of the measured value; (<b>b</b>) FPS value.</p> Full article ">Figure 6
<p>Performance results of tomato plant height detection by different comparison methods. (<b>a</b>) Linearity deviation of the measured value; (<b>b</b>) FPS value.</p> Full article ">
Open AccessArticle
Molecular Energy of Metamorphic Coal and Methane Adsorption Based on Gaussian Simulation
by
Tao Yang, Jingyan Hu, Tao Li, Heng Min and Shuchao Zhang
Processes 2024, 12(12), 2621; https://doi.org/10.3390/pr12122621 - 21 Nov 2024
Abstract
Effectively controlling the adsorption and desorption of coal and mine gas is crucial to preventing harm to the environment. Therefore, this paper investigated the adsorption of coal and methane molecules from the perspective of microscopic energy through Gaussian simulation. Gaussian 09W and GaussView
[...] Read more.
Effectively controlling the adsorption and desorption of coal and mine gas is crucial to preventing harm to the environment. Therefore, this paper investigated the adsorption of coal and methane molecules from the perspective of microscopic energy through Gaussian simulation. Gaussian 09W and GaussView 5.0 software were used to construct and optimize the molecular model of four different metamorphic coals, namely lignite, sub-bituminous coal, bituminous coal, and anthracite, and their adsorption structure with methane as well as the energy, bond length, vibration frequency, infrared spectrum, and other data on the optimal structure were obtained. The binding energy of coal molecules and methane from large to small was as follows: sub-bituminous coal (7.3696 KJ/mol), lignite (6.6149 KJ/mol), bituminous coal (5.2170 KJ/mol), and anthracite (4.9510 KJ/mol). The equilibrium distance was negatively correlated with the binding energy, and the molecular structure and position of coal largely determined the binding energy. Additionally, adsorption was more likely to occur between methane molecules and hydroxyl groups. Many new vibration modes were observed during the adsorption of coal and methane molecules. This paper is of practical significance, as studying the adsorption of coal and mine gas can prevent and control mine gas outbursts and ensure safe production.
Full article
(This article belongs to the Topic Energy Extraction and Processing Science)
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Show Figures
Figure 1
Figure 1
<p>Gaussian simulation operation interface. (<b>a</b>) Energy change trend. (<b>b</b>) Vibration frequency.</p> Full article ">Figure 2
<p>Molecular structure diagram of different metamorphic coals: (<b>a</b>) lignite (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 3
<p>Optimal structure model of different metamorphic coal molecules: (<b>a</b>) lignite (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 4
<p>Molecular energy values of different metamorphic coals.</p> Full article ">Figure 5
<p>Infrared spectra of different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">Figure 5 Cont.
<p>Infrared spectra of different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">Figure 6
<p>Binding energy of different adsorption positions of lignite.</p> Full article ">Figure 7
<p>Binding energy of different adsorption positions of sub-bituminous coal.</p> Full article ">Figure 8
<p>Binding energy of different adsorption positions of bituminous coal.</p> Full article ">Figure 9
<p>Binding energy of different adsorption positions of anthracite.</p> Full article ">Figure 10
<p>Optimal structure model of methane molecules adsorbed by different metamorphic coal molecules. (<b>a</b>) lignite, (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 11
<p>Adsorption equilibrium distance of different metamorphic coal molecules.</p> Full article ">Figure 12
<p>Binding energy of different metamorphic coal molecules after adsorption.</p> Full article ">Figure 13
<p>Infrared spectra of the optimal configuration of methane adsorbed by different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">
<p>Gaussian simulation operation interface. (<b>a</b>) Energy change trend. (<b>b</b>) Vibration frequency.</p> Full article ">Figure 2
<p>Molecular structure diagram of different metamorphic coals: (<b>a</b>) lignite (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 3
<p>Optimal structure model of different metamorphic coal molecules: (<b>a</b>) lignite (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 4
<p>Molecular energy values of different metamorphic coals.</p> Full article ">Figure 5
<p>Infrared spectra of different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">Figure 5 Cont.
<p>Infrared spectra of different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">Figure 6
<p>Binding energy of different adsorption positions of lignite.</p> Full article ">Figure 7
<p>Binding energy of different adsorption positions of sub-bituminous coal.</p> Full article ">Figure 8
<p>Binding energy of different adsorption positions of bituminous coal.</p> Full article ">Figure 9
<p>Binding energy of different adsorption positions of anthracite.</p> Full article ">Figure 10
<p>Optimal structure model of methane molecules adsorbed by different metamorphic coal molecules. (<b>a</b>) lignite, (<b>b</b>) sub-bituminous coal, (<b>c</b>) bituminous coal, (<b>d</b>) anthracite.</p> Full article ">Figure 11
<p>Adsorption equilibrium distance of different metamorphic coal molecules.</p> Full article ">Figure 12
<p>Binding energy of different metamorphic coal molecules after adsorption.</p> Full article ">Figure 13
<p>Infrared spectra of the optimal configuration of methane adsorbed by different metamorphic coal molecules. (<b>a</b>) Lignite. (<b>b</b>) Sub-bituminous coal. (<b>c</b>) Bituminous coal. (<b>d</b>) Anthracite.</p> Full article ">
Open AccessArticle
Application of SPEA2-MMBB for Distributed Fault Diagnosis in Nuclear Power System
by
Ying Xu, Jie Ma and Jinxiao Yuan
Processes 2024, 12(12), 2620; https://doi.org/10.3390/pr12122620 - 21 Nov 2024
Abstract
Accurate fault diagnosis in nuclear power systems is essential for ensuring reactor stability, reducing the risk of potential faults, enhancing system reliability, and maintaining operational safety. Traditional diagnostic methods, especially those based on single-system approaches, struggle to address the complexities of composite faults
[...] Read more.
Accurate fault diagnosis in nuclear power systems is essential for ensuring reactor stability, reducing the risk of potential faults, enhancing system reliability, and maintaining operational safety. Traditional diagnostic methods, especially those based on single-system approaches, struggle to address the complexities of composite faults and highly coupled fault data. In this paper, we introduce a distributed fault diagnosis method for nuclear power systems that leverages the Strength Pareto Evolutionary Algorithm 2 (SPEA2) for multi-objective optimization and a modified MobileNetV3 neural network with a Bottleneck Attention Module (MMBB). The SPEA2 algorithm is used to optimize sensor feature selection, and the sensor data are then input into the MMBB model for training. The MMBB model outputs accuracy rates for each subsystem and the overall system, which are subsequently used as optimization targets to guide SPEA2 in refining the sensor selection process for distributed diagnosis. The experimental results demonstrate that this method significantly enhances subsystem accuracy, with an average accuracy of 98.73%, and achieves a comprehensive system accuracy of 95.22%, indicating its superior performance compared to traditional optimization and neural network-based approaches.
Full article
(This article belongs to the Special Issue Research on Intelligent Fault Diagnosis Based on Neural Network)
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Show Figures
Figure 1
Figure 1
<p>Flowchart of the SPEA2 algorithm.</p> Full article ">Figure 2
<p>Architecture of the MMBB model.</p> Full article ">Figure 3
<p>Structure of the inverted residual block.</p> Full article ">Figure 4
<p>Structure of the BAM module.</p> Full article ">Figure 5
<p>Flowchart of the structure of the optimization process.</p> Full article ">Figure 6
<p>The structure of the Reactor Coolant System and the locations of the faults.</p> Full article ">Figure 7
<p>(<b>a</b>) Add tags and segment_id to fault data according to subsystems. (<b>b</b>) Add time windows to fault data. (<b>c</b>) Splice data horizontally and remove transition sequences.</p> Full article ">Figure 8
<p>Subsystem accuracy and overall accuracy from the SPEA2-MMBB.</p> Full article ">Figure 9
<p>(<b>a</b>) Test set accuracy over epochs for the sixth elite individual. (<b>b</b>) Training set loss over epochs for the sixth elite individual.</p> Full article ">Figure 10
<p>(<b>a</b>) Confusion matrix of Subsystem 1. (<b>b</b>) Confusion matrix of Subsystem 2. (<b>c</b>) Confusion matrix of Subsystem 3. (<b>d</b>) Confusion matrix of Subsystem 4. (<b>e</b>) Confusion matrix of Subsystem 5. (<b>f</b>) Confusion matrix of Subsystem 6.</p> Full article ">
<p>Flowchart of the SPEA2 algorithm.</p> Full article ">Figure 2
<p>Architecture of the MMBB model.</p> Full article ">Figure 3
<p>Structure of the inverted residual block.</p> Full article ">Figure 4
<p>Structure of the BAM module.</p> Full article ">Figure 5
<p>Flowchart of the structure of the optimization process.</p> Full article ">Figure 6
<p>The structure of the Reactor Coolant System and the locations of the faults.</p> Full article ">Figure 7
<p>(<b>a</b>) Add tags and segment_id to fault data according to subsystems. (<b>b</b>) Add time windows to fault data. (<b>c</b>) Splice data horizontally and remove transition sequences.</p> Full article ">Figure 8
<p>Subsystem accuracy and overall accuracy from the SPEA2-MMBB.</p> Full article ">Figure 9
<p>(<b>a</b>) Test set accuracy over epochs for the sixth elite individual. (<b>b</b>) Training set loss over epochs for the sixth elite individual.</p> Full article ">Figure 10
<p>(<b>a</b>) Confusion matrix of Subsystem 1. (<b>b</b>) Confusion matrix of Subsystem 2. (<b>c</b>) Confusion matrix of Subsystem 3. (<b>d</b>) Confusion matrix of Subsystem 4. (<b>e</b>) Confusion matrix of Subsystem 5. (<b>f</b>) Confusion matrix of Subsystem 6.</p> Full article ">
Open AccessArticle
Investigation of Influence of High Pressure on the Design of Deep-Water Horizontal Separator and Droplet Evolution
by
Yuehong Cui, Ming Zhang, Haiyan Wang, Hualei Yi, Meng Yang, Lintong Hou, Shuo Liu and Jingyu Xu
Processes 2024, 12(12), 2619; https://doi.org/10.3390/pr12122619 - 21 Nov 2024
Abstract
Under deep-water high-pressure conditions, the multiphase flow characteristics within separators show significant differences compared to conventional separators. When designing subsea separators, it is crucial to consider the impact of pressure to ensure that the design meets the separation objectives while remaining cost effective.
[...] Read more.
Under deep-water high-pressure conditions, the multiphase flow characteristics within separators show significant differences compared to conventional separators. When designing subsea separators, it is crucial to consider the impact of pressure to ensure that the design meets the separation objectives while remaining cost effective. This study enhances the theoretical foundations of subsea separator design by analyzing droplet motion behaviors under high pressure and incorporating these influences into a rational design framework. A horizontal separator was designed and integrated into a laboratory-scale separation system for experimental validation. Through the comprehensive testing of separation efficiencies and process dynamics, it was found that increased pressures resulted in a decrease in oil droplet sizes; at pressures exceeding 6 MPa, droplet diameters were observed to drop below 100 μm. This reduction in droplet size extends the required separation time, necessitating larger separator dimensions at higher operational pressures to maintain adequate separation quality. Numerical simulations complement experimental findings by clarifying the underlying separation mechanisms under high-pressure conditions and offering design recommendations for separators deployed in deep-water environments.
Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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Show Figures
Figure 1
Figure 1
<p>Description of separator: (<b>a</b>) the schematic of the separator; (<b>b</b>) mesh of the separator.</p> Full article ">Figure 2
<p>Experimental system.</p> Full article ">Figure 3
<p>The samples at rest following the extraction process.</p> Full article ">Figure 4
<p>Test water samples. (Sampled from water out with pressure labeled).</p> Full article ">Figure 5
<p>Oil content in the samples.</p> Full article ">Figure 6
<p>Schematic illustration of changes in the water layer.</p> Full article ">Figure 7
<p>Variation in the volume of separated water: (<b>a</b>) <span class="html-italic">P</span> = 0.5 MPa; (<b>b</b>) <span class="html-italic">P</span> = 2.0 MPa; (<b>c</b>) <span class="html-italic">P</span> = 4.0 MPa; (<b>d</b>) <span class="html-italic">P</span> = 6.0 MPa.</p> Full article ">Figure 8
<p>Simulation of oil–water separation process: (<b>a</b>) <span class="html-italic">P</span> = 0.5 MPa; (<b>b</b>) <span class="html-italic">P</span> = 2.0 MPa; (<b>c</b>) <span class="html-italic">P</span> = 4.0 MPa; (<b>d</b>) <span class="html-italic">P</span> = 6.0 MPa.</p> Full article ">Figure 9
<p>Simulated water layer versus measured water layer.</p> Full article ">
<p>Description of separator: (<b>a</b>) the schematic of the separator; (<b>b</b>) mesh of the separator.</p> Full article ">Figure 2
<p>Experimental system.</p> Full article ">Figure 3
<p>The samples at rest following the extraction process.</p> Full article ">Figure 4
<p>Test water samples. (Sampled from water out with pressure labeled).</p> Full article ">Figure 5
<p>Oil content in the samples.</p> Full article ">Figure 6
<p>Schematic illustration of changes in the water layer.</p> Full article ">Figure 7
<p>Variation in the volume of separated water: (<b>a</b>) <span class="html-italic">P</span> = 0.5 MPa; (<b>b</b>) <span class="html-italic">P</span> = 2.0 MPa; (<b>c</b>) <span class="html-italic">P</span> = 4.0 MPa; (<b>d</b>) <span class="html-italic">P</span> = 6.0 MPa.</p> Full article ">Figure 8
<p>Simulation of oil–water separation process: (<b>a</b>) <span class="html-italic">P</span> = 0.5 MPa; (<b>b</b>) <span class="html-italic">P</span> = 2.0 MPa; (<b>c</b>) <span class="html-italic">P</span> = 4.0 MPa; (<b>d</b>) <span class="html-italic">P</span> = 6.0 MPa.</p> Full article ">Figure 9
<p>Simulated water layer versus measured water layer.</p> Full article ">
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