Processes

15 pages, 4865 KB

Open AccessFeature PaperArticle

Influence of Ultrasound Frequency as a Preliminary Treatment on the Physicochemical, Structural, and Sensory Properties of Fried Native Potato Chips

by Henry Palomino-Rincón, Betsy S. Ramos-Pacheco, Dianeth Buleje Campos, Rodrigo J. Guzmán Gutiérrez, Evelin M. Yauris-Navez and Elizabeth Alarcón-Quispe

Processes 2025, 13(8), 2668; https://doi.org/10.3390/pr13082668 - 21 Aug 2025

Cited by 1 | Viewed by 1071

Abstract

Frying native potato chips produces snacks that are widely accepted, although they are associated with high fat content and the formation of potentially undesirable compounds. This study evaluated the effect of pretreatment with ultrasound at 28 and 40 kHz on the physicochemical, structural, [...] Read more.

Frying native potato chips produces snacks that are widely accepted, although they are associated with high fat content and the formation of potentially undesirable compounds. This study evaluated the effect of pretreatment with ultrasound at 28 and 40 kHz on the physicochemical, structural, and sensory properties of chips made from the Sempal and Agustina varieties. The chips were immersed in water and treated with ultrasound for 10 min before frying at 175 °C. Parameters such as moisture, fat content, water activity, color, reducing sugars, FTIR spectroscopy, SEM microscopy, and sensory acceptance by consumers were analyzed. Treatment with 40 kHz significantly reduced fat content (up to 22.07%), improved crispness, and promoted a more porous microstructure. A lower concentration of reducing sugars, greater brightness, and less darkening were also observed. Sensory evaluation showed that chips treated with 40 kHz were the most preferred and best rated in terms of texture and flavor. Finally, it was demonstrated that pretreatment with ultrasound at 40 kHz improved the technological and sensory quality of native potato chips, which would promote the value of these resources in healthy products. Full article

(This article belongs to the Special Issue Emerging Technologies for the Valorization of Agro-Food Byproducts into Functional Ingredients and Foods)

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25 pages, 20084 KB

Open AccessArticle

Phase Evolution History of Deep-Seated Hydrocarbon Fluids in the Western Junggar Basin: Insights from Geochemistry, PVT, and Basin Modeling

by Maoguo Hou, Xiujian Ding, Chenglin Chu, Jie Wang, Jiwen Huang, Hailei Liu, Wenlong Jiang, Ming Zha, Gang Yue and Keshun Liu

Processes 2025, 13(8), 2667; https://doi.org/10.3390/pr13082667 - 21 Aug 2025

Viewed by 514

Abstract

Clarifying the phase evolution history of hydrocarbon fluids helps formulate exploration and development strategies. The discovery of the Xinguang Gas Field marks a significant breakthrough in the Western Junggar Basin. However, the phase evolution history of this gas field remains unclear, which hinders [...] Read more.

Clarifying the phase evolution history of hydrocarbon fluids helps formulate exploration and development strategies. The discovery of the Xinguang Gas Field marks a significant breakthrough in the Western Junggar Basin. However, the phase evolution history of this gas field remains unclear, which hinders the formulation of subsequent exploration strategies. This study employs a comprehensive approach, combining organic geochemistry, fluid inclusions, basin modeling, and PVT testing and simulation, to investigate the characteristics and phase behavior of deep-seated hydrocarbon fluids in this gas field. It also examines the charging history, compositional evolution, and temperature and pressure histories of the reservoir, thereby clarifying the phase transition process of hydrocarbon fluids in the Xinguang Gas Field. This study finds that the deep-seated reservoir fluids in the Jiamuhe Formation (Fm.) of the Xinguang Gas Field exhibit low densities of 0.77 to 0.83 g/cm³, high gas-to-oil ratios (GORs) of 1014.41 to 13,054.77 m³/m³, high methane contents of 91.16% to 92.74%, and retrograde condensation characteristics. Additionally, the reservoir temperature and pressure exceed the critical point and the saturation pressure at reservoir temperature, indicating a supercritical condensate gas phase. The present condensate gas in the Xinguang Gas Field is a mixed hydrocarbon from two charging events. Initially, during the Middle–Late Triassic period, both Block 1 and the Xinguang Gas Field were charged with mature oil. Later, from the Late Cretaceous to Early Neogene periods, a secondary charging of highly mature oil and gas occurred in the Xinguang Gas Field, while the reservoir in Block 1 remained largely unchanged. In the co-evolution of reservoir fluid composition, temperature, and pressure, the phase transitions of the hydrocarbon fluids in the Xinguang Gas Field passed through several stages, including liquid black oil (231.9–80.3 Ma), liquid volatile oil (80.3–79.1 Ma), vapor–liquid two-phase volatile oil (79.1–78.3 Ma), vapor–liquid two-phase condensate gas (78.3–69.1 Ma), and supercritical condensate gas (69.1 Ma–present). Full article

(This article belongs to the Section Energy Systems)

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21 pages, 7455 KB

Open AccessArticle

A Method for Predicting Gas Well Productivity in Non-Dominant Multi-Layer Tight Sandstone Reservoirs of the Sulige Gas Field Based on Multi-Task Learning

by Dawei Liu, Shiqing Cheng, Han Wang and Yang Wang

Processes 2025, 13(8), 2666; https://doi.org/10.3390/pr13082666 - 21 Aug 2025

Cited by 1 | Viewed by 562

Abstract

This study proposes a multi-task learning-based production capacity prediction model aimed at improving the prediction accuracy for gas wells in multi-layer tight sandstone reservoirs of the Sulige gas field under small-sample conditions. The model integrates mutation theory and progressive hierarchical feature extraction to [...] Read more.

This study proposes a multi-task learning-based production capacity prediction model aimed at improving the prediction accuracy for gas wells in multi-layer tight sandstone reservoirs of the Sulige gas field under small-sample conditions. The model integrates mutation theory and progressive hierarchical feature extraction to achieve adaptive nonlinear feature extraction and autonomous feature selection tailored to different prediction tasks. Using the daily average production of each gas-bearing layer during the first month after well commencement and the cumulative production of each gas-bearing layer over the first year as targets, the model was applied to predict the production capacity of 66 gas wells. Compared with single-task models and classical machine learning methods, the proposed multi-task model significantly improves prediction accuracy, reducing the root mean squared error (RMSE) by over 40% and increasing the coefficient of determination (R²) to 0.82. Experimental results demonstrate the model’s effectiveness in environments with limited training data, offering a reliable approach for productivity prediction in complex multi-layer tight sandstone reservoirs. Full article

(This article belongs to the Special Issue 2nd Edition of Artificial Intelligent Techniques in the Optimal Operation of Oil and Gas Production Systems)

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14 pages, 1781 KB

Open AccessArticle

Metal Phosphomolybdate-Catalyzed Condensation of Furfural with Glycerol

by Márcio José da Silva, Pedro Henrique da Silva Andrade and Luiza Diogo Miranda

Processes 2025, 13(8), 2665; https://doi.org/10.3390/pr13082665 - 21 Aug 2025

Viewed by 512

Abstract

In this work, metal salts of phosphomolybdic acid were prepared and evaluated as catalysts in acetalization reactions of glycerol with furfural. These substrates have a renewable origin and play a crucial role in synthesizing bioadditives, which can enhance the physicochemical properties of fossil [...] Read more.

In this work, metal salts of phosphomolybdic acid were prepared and evaluated as catalysts in acetalization reactions of glycerol with furfural. These substrates have a renewable origin and play a crucial role in synthesizing bioadditives, which can enhance the physicochemical properties of fossil fuels and mitigate greenhouse gas emissions. Moreover, the biodiesel industry has generated a surplus of glycerol, and its use as a reactant is welcome from both economic and environmental viewpoints. Keggin heteropolyacid salts are less corrosive than traditional Brønsted acid catalysts and are easier to handle. Herein, metal phosphomolybdates were easily obtained from the acid precursor and metal chloride metathesis. A series of metal phosphomolybdates with the general formulae M₃[PMo₁₂O₄₀]_x n H₂O (M^x+ = Al³⁺, Fe³⁺, Co²⁺, Cu²⁺, Ni²⁺) was prepared and tested as catalysts in furfural glycerol acetalization reactions. Full article

(This article belongs to the Special Issue Continuous Production and Catalysis Optimization of Chemical Industry Processes)

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18 pages, 5104 KB

Open AccessArticle

Analysis of the Effectiveness Mechanism and Research on Key Influencing Factors of High-Pressure Water Injection in Low-Permeability Reservoirs

by Yang Li, Hualei Xu, Shanshan Fu, Hongtao Zhao, Ziqi Chen, Xuejing Bai, Jianyu Li, Chunhong Xiu, Lianshe Zhang and Jie Wang

Processes 2025, 13(8), 2664; https://doi.org/10.3390/pr13082664 - 21 Aug 2025

Cited by 2 | Viewed by 707

Abstract

Low-permeability oil reservoirs, due to their weak seepage capacity and high start-up pressure, have limited yield-increasing effects through conventional water injection development methods. High-pressure water injection can significantly change the seepage environment around the well and within the reservoir, expand the effective swept [...] Read more.

Low-permeability oil reservoirs, due to their weak seepage capacity and high start-up pressure, have limited yield-increasing effects through conventional water injection development methods. High-pressure water injection can significantly change the seepage environment around the well and within the reservoir, expand the effective swept volume of injected water, and thereby greatly enhance the oil recovery rate of water flooding. However, there is still a relative lack of research on the mechanism of high-pressure water injection stimulation and its influencing factors. This paper systematically analyzes the effectiveness mechanism of high-pressure water injection technology in the exploitation of low-permeability reservoirs. The internal mechanism of high-pressure water injection for effective fluid drive and production increase is explained from the aspects of low-permeability reservoir seepage characteristics, capacity expansion and permeability enhancement by high-pressure water injection, and the dynamic induction of micro-fractures. Based on geological and engineering factors, the main factors affecting the efficiency enhancement of high-pressure water injection are studied, including formation deficit, reservoir heterogeneity, dominant channel development and fracturing stimulation measures, injection displacement and micro-fractures, etc. The results of numerical simulation showed the following: (1) formation depletion, reservoir heterogeneity, and the formation of dominant channels significantly affected the effect of water flooding development and (2) engineering factors such as the fracture direction of hydraulic fracturing, water injection rate, and the development of micro-fractures under high-pressure water injection directly determined the propagation path of reservoir pressure, the breakthrough speed of the water drive front, and the ultimate recovery factor. Therefore, during the actual development process, the construction design parameters of high-pressure water injection should be reasonably determined based on the geological reservoir conditions to maximize the oil production increase effect of high-pressure water injection. This study can successfully provide theoretical guidance and practical support for the development of low-permeability oil reservoirs. Full article

(This article belongs to the Special Issue Recent Advances in Hydrocarbon Production Processes from Geoenergy)

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17 pages, 3601 KB

Open AccessArticle

Relationship Between the Strength Parameters of Tectonic Soft Coal and the Fractal Dimension Number Based on Particle Size Grading

by Ying Han, Feifan Shan, Feiyan Zhang and Qingchao Li

Processes 2025, 13(8), 2663; https://doi.org/10.3390/pr13082663 - 21 Aug 2025

Viewed by 428

Abstract

Based on mechanical experiments conducted on bulk raw coal and coal of different types in order to explore the correlations between the fractal dimension and the grain size gradation and strength parameters of coal samples, the fractal statistics method was used to statistically [...] Read more.

Based on mechanical experiments conducted on bulk raw coal and coal of different types in order to explore the correlations between the fractal dimension and the grain size gradation and strength parameters of coal samples, the fractal statistics method was used to statistically analyze the grain size distribution characteristics of tectonic soft coal, while fractal theory was applied to study the grain size fractal characteristics of tectonic soft coals of categories III–V. The results of this study show that coal types III–V have increasing fractal dimension numbers, and the content of coarse particles decreases with an increasing fractal dimension number. Within this sampling range, the Class V coal is better graded, and the fractal dimension number decreases as the distance of the sampling point from the fault zone increases. In the direct shear experiments, the internal friction angle of the bulk raw coal decreased linearly with an increasing fractal dimension number, and the regularity of the cohesive force and the fractal dimension number was not strong, but the adhesion cohesion of the types of coal exhibited a positive exponential relationship with the fractal dimension, and the relationship between the internal friction angle and the fractal dimension was not strong. There was a positive exponential relationship, and the internal friction angle was relatively stable. The uniaxial compressive strength of the types of coal exhibited a good correlation with the coefficient of firmness of the coal samples and the fractal dimension, and the coefficient of firmness of the coal samples was the main factor influencing the uniaxial compressive strength of the types of coal compared with the particle size gradation. Full article

(This article belongs to the Special Issue Environmentally Friendly Production of Energy from Natural Gas Hydrates)

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20 pages, 1474 KB

Open AccessFeature PaperReview

Recent Advances in Moderate Electric Field (MEF) Systems for Sustainable Food Processing

by Tesfaye Bedane, Francesco Marra, Norman Maloney and James Lyng

Processes 2025, 13(8), 2662; https://doi.org/10.3390/pr13082662 - 21 Aug 2025

Viewed by 1081

Abstract

Moderate electric field (MEF) technology is an electro-heating technology that involves the application of electric fields less than 1000 V cm⁻¹, with or without the effect of heat, to induce heating and enhance mass transfer in food processing operations. The rapid [...] Read more.

Moderate electric field (MEF) technology is an electro-heating technology that involves the application of electric fields less than 1000 V cm⁻¹, with or without the effect of heat, to induce heating and enhance mass transfer in food processing operations. The rapid heating capabilities and higher energy efficiency make MEF a viable alternative to traditional processing methods in the food industry. Recent advancements in MEF processing of foods have focused on optimizing equipment design and process parameters and integrating digital tools to broaden their application across a wide range of food processes. This review provides a comprehensive overview of recent developments related to the design of MEF systems for various operations, including single and multicomponent food systems. The thermal efficiency and energy saving of MEF treatment in various food processing operations largely depend on the type and arrangement of the electrodes, and operating frequency and composition of the food matrix. A thorough understanding of the electrical properties of single and multicomponent food systems is crucial for analyzing their behavior and interactions with applied electric fields, and for designing an efficient MEF system. In addition, integrating digital tools and physics-based models could play a significant role in real-time monitoring, predictive process control, and process optimization to enhance productivity, reduce energy consumption, and ensure improved product quality and safety. This makes the MEF technology economically viable and sustainable, which also improves the scalability and integration into existing processing lines. Full article

(This article belongs to the Special Issue Emerging Thermal and Non-Thermal Technologies for Food Preservation and Sustainable Food Processing)

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14 pages, 1446 KB

Open AccessArticle

CFD-Based Analysis of Sound Wave Attenuation in Stratified Gas–Liquid Pipelines for Leak Detection Applications

by Birungi Joseph Kironde, Johnson Joachim Kasali and Yuxing Li

Processes 2025, 13(8), 2661; https://doi.org/10.3390/pr13082661 - 21 Aug 2025

Viewed by 505

Abstract

Sound wave attenuation in stratified gas–liquid flows is crucial for pipeline monitoring and leak detection. This study uses computational fluid dynamics (CFD) to investigate acoustic wave propagation in pipelines, employing the Volume of Fluid (VOF) model with interfacial tension and a pressure-based solver. [...] Read more.

Sound wave attenuation in stratified gas–liquid flows is crucial for pipeline monitoring and leak detection. This study uses computational fluid dynamics (CFD) to investigate acoustic wave propagation in pipelines, employing the Volume of Fluid (VOF) model with interfacial tension and a pressure-based solver. The effects of the gas volume fraction, pressure, frequency, and grid resolution are analyzed, with validation through mesh independence tests. The findings show that incorporating mesh refinement and boundary layer modeling improved attenuation prediction accuracy by approximately 25–30%. High-frequency waves (above 150 Hz) exhibited up to 30% greater attenuation when near-wall viscous effects were resolved, demonstrating the need for fine grid resolution in CFD-based multiphase diagnostic tools. This study highlights the importance of wave frequency, grid refinement, and boundary layer modeling for accurate attenuation predictions, offering insights for the improvement of CFD-based diagnostic tools in multiphase flow systems. Full article

(This article belongs to the Section Process Control and Monitoring)

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26 pages, 1505 KB

Open AccessReview

Application of Electrochemical Oxidation for Urea Removal: A Review

by Juwon Lee, Jeongbeen Park, Intae Shim, Jae-Wuk Koo, Sook-Hyun Nam, Eunju Kim, Seung-Min Park and Tae-Mun Hwang

Processes 2025, 13(8), 2660; https://doi.org/10.3390/pr13082660 - 21 Aug 2025

Cited by 1 | Viewed by 1498

Abstract

The consistent quality control of ultrapure water (UPW) in semiconductor manufacturing depends on removing trace organonitrogen compounds such as urea. Due to its high solubility, chemical stability, and neutral polarity, urea is inadequately removed by conventional processes. Even at low concentrations, it elevates [...] Read more.

The consistent quality control of ultrapure water (UPW) in semiconductor manufacturing depends on removing trace organonitrogen compounds such as urea. Due to its high solubility, chemical stability, and neutral polarity, urea is inadequately removed by conventional processes. Even at low concentrations, it elevates total organic carbon (TOC) and reduces electrical resistivity. The use of reclaimed water as a sustainable feed stream amplifies this challenge because its nitrogen content is variable and persistent. Conventional methods such as reverse osmosis, ultraviolet oxidation, and ion exchange remain limited in treating urea due to its uncharged, low-molecular-weight nature. This review examines the performance and limitations of these processes and explores electrochemical oxidation (EO) as an alternative. Advances in EO are analyzed with attention to degradation pathways, electrode design, reaction selectivity, and operational parameters. Integrated systems combining EO with membrane filtration, adsorption, or chemical oxidation are also reviewed. Although EO shows promise for selectively degrading urea, its application in UPW production is still in its early stages. Challenges such as low conductivity, byproduct formation, and energy efficiency must be addressed. The paper first discusses urea in reclaimed water and associated removal challenges, then examines both conventional and emerging treatment technologies. Subsequent sections delve into the mechanisms and optimization of EO, including electrode materials and operational parameters. The review concludes with a summary of main findings and a discussion of future research directions, aiming to provide a comprehensive foundation for validating EO as a viable technology for producing UPW from reclaimed water. Full article

(This article belongs to the Special Issue Addressing Environmental Issues with Advanced Oxidation Technologies)

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24 pages, 1866 KB

Open AccessReview

Overview of Topics in Electrocatalysis for Sustainability: Reactions, Electrocatalysts, Degradation, and Mitigation

by Varada Purohit and Avdhoot Datar

Processes 2025, 13(8), 2659; https://doi.org/10.3390/pr13082659 - 21 Aug 2025

Viewed by 688

Abstract

Electrocatalysis provides an avenue for transitioning the global energy dependence from fossil fuels to renewable energy sources. While electrocatalytic reactions have been used for several decades, recently, there is a growing interest in electrocatalytic reactions that are useful from a sustainability perspective. The [...] Read more.

Electrocatalysis provides an avenue for transitioning the global energy dependence from fossil fuels to renewable energy sources. While electrocatalytic reactions have been used for several decades, recently, there is a growing interest in electrocatalytic reactions that are useful from a sustainability perspective. The wide industrial applications of these sustainable electrocatalytic processes are largely limited by the degradation of the electrocatalysts. This review begins with an introduction to such reactions, followed by a detailed discussion of the electrocatalysts. Further, we describe the processes that are responsible for the degradation of electrocatalytic activity. Then, the strategies for reducing the degradation of electrocatalysts are discussed. This review also touches on the broader techno-economic and life-cycle considerations in catalyst development, linking fundamental research with practical sustainability. Full article

(This article belongs to the Special Issue Advances in Electrocatalysts for the OER, HER and Biomass Conversion)

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27 pages, 6026 KB

Open AccessFeature PaperArticle

Application of an Automated Machine Learning-Driven Grid Block Classification Framework to a Realistic Deep Saline Aquifer Model for Accelerating Numerical Simulations of CO₂ Geological Storage

by Eirini Maria Kanakaki, Sofianos Panagiotis Fotias and Vassilis Gaganis

Processes 2025, 13(8), 2658; https://doi.org/10.3390/pr13082658 - 21 Aug 2025

Cited by 1 | Viewed by 590

Abstract

Numerical simulations are essential for optimizing CO₂ geological storage in deep saline aquifers; however, their substantial computational demands pose a significant challenge. This study introduces an automated machine learning (ML)-driven grid block classification framework applied to a realistic deep saline aquifer model [...] Read more.

Numerical simulations are essential for optimizing CO₂ geological storage in deep saline aquifers; however, their substantial computational demands pose a significant challenge. This study introduces an automated machine learning (ML)-driven grid block classification framework applied to a realistic deep saline aquifer model to accelerate numerical simulations while maintaining accuracy. The methodology employs an ML and interquartile range-based classifier to distinguish grid blocks as either fast- or slow-varying. ML-based proxy models are applied exclusively to slow-varying regions, while traditional iterative methods handle dynamic, fast-varying regions. Results confirm a considerable reduction in computational costs without compromising predictive accuracy. Validated under realistic reservoir conditions, the approach demonstrates scalability and robustness, supporting efficient, accurate large-scale CO₂ storage simulations and advancing sustainable subsurface sequestration strategies. Full article

(This article belongs to the Special Issue 2nd Edition of Artificial Intelligent Techniques in the Optimal Operation of Oil and Gas Production Systems)

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22 pages, 6265 KB

Open AccessArticle

A Multi-Level Fusion Framework for Bearing Fault Diagnosis Using Multi-Source Information

by Xiaojun Deng, Yuanhao Sun, Lin Li and Xia Peng

Processes 2025, 13(8), 2657; https://doi.org/10.3390/pr13082657 - 21 Aug 2025

Cited by 2 | Viewed by 766

Abstract

Rotating machinery is essential to modern industrial systems, where rolling bearings play a critical role in ensuring mechanical stability and operational efficiency. Failures in bearings can result in serious safety risks and significant financial losses, which highlights the need for accurate and robust [...] Read more.

Rotating machinery is essential to modern industrial systems, where rolling bearings play a critical role in ensuring mechanical stability and operational efficiency. Failures in bearings can result in serious safety risks and significant financial losses, which highlights the need for accurate and robust methods for diagnosing bearing faults. Traditional diagnostic methods relying on single-source data often fail to fully leverage the rich information provided by multiple sensors and are more prone to performance degradation under noisy conditions. Therefore, this paper proposes a novel bearing fault diagnosis method based on a multi-level fusion framework. First, the Symmetrized Dot Pattern (SDP) method is applied to fuse multi-source signals into unified SDP images, enabling effective fusion at the data level. Then, a combination of RepLKNet and Bidirectional Gated Recurrent Unit (BiGRU) networks extracts multi-modal features, which are then fused through a cross-attention mechanism to enhance feature representation. Finally, information entropy is utilized to assess the reliability of each feature channel, enabling dynamic weighting to further strengthen model robustness. The experiments conducted on public datasets and noise-augmented datasets demonstrate that the proposed method significantly surpasses other single-source and multi-source data fusion models in terms of diagnostic accuracy and robustness to noise. Full article

(This article belongs to the Section Process Control and Monitoring)

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29 pages, 5893 KB

Open AccessFeature PaperReview

Solid Oxide Electrolyzers Process Integration: A Comprehensive Review

by Fernando Ferrete, Ana Molina, Gracia María Cabello González, Ángeles Moreno-Racero, Henar Olmedo and Alfredo Iranzo

Processes 2025, 13(8), 2656; https://doi.org/10.3390/pr13082656 - 21 Aug 2025

Cited by 1 | Viewed by 1988

Abstract

Solid oxide electrolysis (SOEL) has emerged as a promising technology for efficient hydrogen production. Its main advantages lie in the high operating temperatures, which enhance thermodynamic efficiency, and in the ability to supply part of the required energy in the form of heat. [...] Read more.

Solid oxide electrolysis (SOEL) has emerged as a promising technology for efficient hydrogen production. Its main advantages lie in the high operating temperatures, which enhance thermodynamic efficiency, and in the ability to supply part of the required energy in the form of heat. Nevertheless, improving the long-term durability of stack materials remains a key challenge. Thermal energy can be supplied by dedicated integration with different industrial processes, where the main challenge lies in the elevated stack operating temperature (700–900 °C). This review provides a comprehensive analysis of the integration of solid oxide electrolysis cells (SOECs) into different industrial applications. Main processes cover methanol production, methane production, Power-to-Hydrogen systems, or the use of reversible solid oxide electrolysis cell (rSOEC) stacks that can operate in both electrolysis and fuel cell mode. The potential of co-electrolysis to increase process flexibility and broaden application areas is also analyzed. The aim is to provide a comprehensive analysis of the integration strategies, identify the main technical and economic challenges, and highlight recent developments and future trends in the field. A detailed comparison assessment of the different processes is being discussed in terms of electrical and thermal efficiencies and operating parameters, as well as Key Performance Indicators (KPIs) for each process. Technical-economic challenges that are currently a barrier to their implementation in industry are also analyzed. Full article

(This article belongs to the Special Issue Sustainable and Intelligent Energy Systems and Processes: Recent Advances and Challenges (2nd Edition))

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16 pages, 1518 KB

Open AccessArticle

Comparative Simulation of Solar Adsorption and Absorption Cooling Systems with Latent Heat Storage with Erythritol and MgCl₂·6H₂O

by Rosenberg J. Romero, Fernando Lara, Eduardo Venegas-Reyes, Moisés Montiel-Gonzalez and Jesús Cerezo

Processes 2025, 13(8), 2655; https://doi.org/10.3390/pr13082655 - 21 Aug 2025

Viewed by 1320

Abstract

The energy requirements for conditioning spaces have been increasing primarily due to population growth and climate change. This paper shows a comparison between an adsorption (ADC) and absorption cooling (ABC) systems to keep a building below the 25 °C set-point in dynamic conditions, [...] Read more.

The energy requirements for conditioning spaces have been increasing primarily due to population growth and climate change. This paper shows a comparison between an adsorption (ADC) and absorption cooling (ABC) systems to keep a building below the 25 °C set-point in dynamic conditions, utilizing a latent heat storage tank with MgCl₂·6H₂O and erythritol, and employing evacuated tube and parabolic trough collectors. The storage tank geometry is a plate heat exchanger. An auxiliary system was incorporated to control the temperature range of the solar cooling systems. The results showed that the coefficient of performance was kept around 0.40–0.60 and 0.70 for adsorption and absorption cooling, respectively. The latent heat storage tank with erythritol captured more solar energy than MgCl₂·6H₂O. A maximum solar fraction of 0.96 was obtained with MgCl₂·6H₂O, a thickness of 0.15 m, 20 m² of parabolic trough collector area, and absorption cooling, while the energy supply was fully satisfied with a solar collector with erythritol, a thickness of 0.1 m, 13 m² of parabolic trough area, and absorption cooling. In general, erythritol obtained better results of solar collector fractions than MCHH; however, it has less thermal stability than MgCl₂·6H₂O, and the cost is higher. Full article

(This article belongs to the Special Issue Thermal Engineering: Energy Conversion, Numerical Simulation, and Advanced Control)

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31 pages, 1463 KB

Open AccessFeature PaperReview

Nuclear Energy as a Strategic Resource: A Historical and Technological Review

by Héctor Quiroga-Barriga, Fabricio Nápoles-Rivera, César Ramírez-Márquez and José María Ponce-Ortega

Processes 2025, 13(8), 2654; https://doi.org/10.3390/pr13082654 - 21 Aug 2025

Viewed by 2754

Abstract

Nuclear energy has undergone a significant transformation over the past decades, driven by technological innovation, shifting safety priorities, and the urgent need to mitigate climate change. This study presents a comprehensive review of the historical evolution, current developments, and future prospects of nuclear [...] Read more.

Nuclear energy has undergone a significant transformation over the past decades, driven by technological innovation, shifting safety priorities, and the urgent need to mitigate climate change. This study presents a comprehensive review of the historical evolution, current developments, and future prospects of nuclear energy as a strategic low-carbon resource. A structured literature review was conducted following Kitchenham’s methodology, covering peer-reviewed articles and institutional reports from 2000 to 2025. Key advances examined include the deployment of Small Modular Reactors, Generation IV technologies, and fusion systems, along with progress in safety protocols, waste management, and regulatory frameworks. Comparative environmental data confirm nuclear power’s low life-cycle CO₂ emissions and high energy density relative to other generation sources. However, major challenges remain, including high capital costs, long construction times, complex waste disposal, and issues of public acceptance. The analysis underscores that nuclear energy, while not a standalone solution, is a critical component of a diversified and sustainable energy mix. Its successful integration will depend on adaptive governance, international cooperation, and enhanced social engagement. Overall, the findings support the role of nuclear energy in achieving global decarbonization targets, provided that safety, equity, and environmental responsibility are upheld. Full article

(This article belongs to the Section Energy Systems)

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11 pages, 1111 KB

Open AccessArticle

Suppression of Sulphur-Reducing Bacteria in Formation Water by Sonoplasma Treatment

by Egor S. Mikhalev, Anna V. Kamler, Vadim M. Bayazitov, Roman V. Nikonov, Igor S. Fedulov, Irina O. Abramova and Giancarlo Cravotto

Processes 2025, 13(8), 2653; https://doi.org/10.3390/pr13082653 - 21 Aug 2025

Viewed by 711

Abstract

In petroleum production processes, the water used to maintain formation pressure often plays a key role and is pumped into injection wells to compensate for the pressure drop in the formation after oil extraction and displacement of the remaining petroleum products to the [...] Read more.

In petroleum production processes, the water used to maintain formation pressure often plays a key role and is pumped into injection wells to compensate for the pressure drop in the formation after oil extraction and displacement of the remaining petroleum products to the development well. The source of such water may be produced by waters extracted together with oil and previously purified from mechanical impurities and hydrocarbons. However, a significant disadvantage of using such water is the presence of pollutants such as sulphur-reducing bacteria (SRB) and a high content of hydrogen sulfide. Traditional purification methods against them show low efficiency. Hydrogen sulfide and SRB are not only a threat of environmental pollution, but they also pose a high risk to pipelines in the petroleum industry due to an increase in the rate of metal corrosion. In this paper, formation water was treated with a field deployment flow-mode plasma discharge unit. A significant decrease in the growth rate of SRB in treated water was achieved. Bacterial growth was suppressed for up to 14 days after three treatment cycles of treatment. The hydrogen sulfide content was reduced by 33% after one cycle of plasma discharge water treatment. Full article

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

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17 pages, 2659 KB

Open AccessArticle

Experimental Study on the Distribution of Boundary Shear Stress at an Overfall

by Zhangxin Qi, Zenghui Wang, Yue Pan and Pengbo Chu

Processes 2025, 13(8), 2652; https://doi.org/10.3390/pr13082652 - 21 Aug 2025

Viewed by 480

Abstract

Overfall flow, characterized by high Froude numbers and intense turbulence, generates boundary shear stress on vertical surfaces, which is considered the direct cause of headcut erosion. This study aims to analyze the hydraulic characteristics of nappe flow over a vertical or near-vertical overfall. [...] Read more.

Overfall flow, characterized by high Froude numbers and intense turbulence, generates boundary shear stress on vertical surfaces, which is considered the direct cause of headcut erosion. This study aims to analyze the hydraulic characteristics of nappe flow over a vertical or near-vertical overfall. Detailed experiments using hot-film anemometry were conducted in an indoor flume to examine the shear stress distribution on vertical surfaces under varying flow rates, overfall heights, and backwater depths. The results show that when the jet dynamic pressure head is less than the backwater depth, the dimensionless relative shear stress and relative depth relationship can be fitted with a beta probability density function. When the dynamic pressure head exceeds the backwater depth, the distribution follows a cubic polynomial form. Dimensional analysis and flow trajectory calculation methods were used to establish shear stress distribution formulas, with determination coefficients of 0.829 and 0.652, and the mean absolute percentage error (MAPE) between the measured and predicted values being 0.106 and 0.081, respectively. The findings provide valuable insights into the effects of complex flow structures on shear stress and offer essential support for the development of scour models for overfall structures. Full article

(This article belongs to the Special Issue Advances in Hydrodynamics, Pollution and Bioavailable Transfers)

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14 pages, 1111 KB

Open AccessArticle

Application of Tween 80 in the Remediation of Diesel-Contaminated Podzolic Soils Under Boreal Conditions

by Anastasiia M. Petrova, Guzel R. Farrahova, Artur V. Duryagin, Ruslan Ya. Bajbulatov and Oleg S. Sutormin

Processes 2025, 13(8), 2651; https://doi.org/10.3390/pr13082651 - 21 Aug 2025

Viewed by 647

Abstract

Surfactant-enhanced remediation is a promising approach for treating petroleum-contaminated soils, particularly in areas where conventional methods are limited by environmental constraints. This study investigates the application of Tween 80, a non-ionic surfactant, for remediating diesel-contaminated Albic Podzolic soils typical of boreal regions. Laboratory [...] Read more.

Surfactant-enhanced remediation is a promising approach for treating petroleum-contaminated soils, particularly in areas where conventional methods are limited by environmental constraints. This study investigates the application of Tween 80, a non-ionic surfactant, for remediating diesel-contaminated Albic Podzolic soils typical of boreal regions. Laboratory experiments were conducted over 90 days, using two surfactant concentrations (3.0 × 10⁻⁴ and 1.5 × 10⁻⁴ mol L⁻¹) and two temperature regimes (22–24 °C and 2–3 °C), simulating seasonal variability in cold-climate contaminated sites. The lower Tween 80 concentration—below the critical micelle concentration—proved more effective, achieving up to 21% total petroleum hydrocarbon (TPH) reduction at ambient temperature and 17% under refrigerated conditions. Treated soils also exhibited pH neutralization, indicating improved chemical stability. Acute toxicity bioassays (Vibrio fischeri and Ceriodaphnia affinis) confirmed the environmental safety of the applied concentrations (≤0.3 mol L⁻¹). These results support the practical use of Tween 80 in the remediation of petroleum-contaminated soils under boreal constraints, providing transferable data for designing safe and efficient field-scale treatment strategies. This work also offers insights that are relevant to remediation policies in cold climates and to the adaptation of surfactant-assisted technologies for diverse field conditions. Full article

(This article belongs to the Special Issue Advances in Remediation of Contaminated Sites: 3rd Edition)

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15 pages, 3602 KB

Open AccessArticle

Remote Monitoring and Energy Grade Evaluation for Water-Based Centrifugal Pumps Based on Browser/Server Architecture

by Shenlong Gao, Mengjiao Zhao, Jingming Liu, Qiang Huang, Yang Liu, Jie Liu and Tie Sun

Processes 2025, 13(8), 2650; https://doi.org/10.3390/pr13082650 - 21 Aug 2025

Cited by 1 | Viewed by 610

Abstract

This study presents an online evaluation system for the energy efficiency grade of centrifugal pump units using a Browser/Server architecture. The system employs direct calculation and characteristic curve fitting methods to evaluate efficiency, with corrections for viscous fluids. It utilizes Java20, SpringBoot2.7x, HTML5, [...] Read more.

This study presents an online evaluation system for the energy efficiency grade of centrifugal pump units using a Browser/Server architecture. The system employs direct calculation and characteristic curve fitting methods to evaluate efficiency, with corrections for viscous fluids. It utilizes Java20, SpringBoot2.7x, HTML5, CSS3, Ajax, and RESTful API technologies for real-time monitoring and evaluation. The system has undergone rigorous testing and full-scale deployment within a petrochemical facility. As demonstrated herein, it delivers exceptional stability and precision, cutting evaluation time substantially while markedly enhancing energy-conservation performance. Full article

(This article belongs to the Section Process Control and Monitoring)

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16 pages, 3343 KB

Open AccessArticle

Mechanical Behavior and Stress Mechanism of Roof Cutting Gob-Side Entry Retaining in Medium-Thick Coal Seams

by Dongping Zhang, Dongming Song, Longping Zhang and Bin Luo

Processes 2025, 13(8), 2649; https://doi.org/10.3390/pr13082649 - 21 Aug 2025

Cited by 1 | Viewed by 557

Abstract

In response to the complex challenges posed by gob-side entry retaining in medium-thick coal seams—specifically, severe stress concentrations and unstable surrounding rock under composite roof structures—this study presents a comprehensive field–numerical investigation centered on the 5-200 working face of the Dianping Coal Mine, [...] Read more.

In response to the complex challenges posed by gob-side entry retaining in medium-thick coal seams—specifically, severe stress concentrations and unstable surrounding rock under composite roof structures—this study presents a comprehensive field–numerical investigation centered on the 5-200 working face of the Dianping Coal Mine, China. A three-dimensional coupled stress–displacement model was developed using FLAC3D to systematically evaluate the mechanical behavior of surrounding rock under varying roof cutting configurations. The parametric study considered roof cutting heights of 6 m, 8 m, and 10 m and cutting angles of 0°, 15°, and 25°, respectively. The results indicate that a roof cutting height of 8 m combined with a 15° inclination provides optimal stress redistribution: the high-stress zone within the coal rib is displaced 2–3 m deeper into the coal body, and roof subsidence is reduced from 2500 mm (no cutting) to approximately 200–300 mm. Field measurements corroborate these findings, showing that on the return airway side with roof cutting, initial and periodic weighting intervals increased by 4.0 m and 5.5 m, respectively, while support resistance was reduced by over 12%. These changes suggest a delayed main roof collapse and decreased dynamic loading on supports, facilitating safer roadway retention. Furthermore, surface monitoring reveals that roof cutting significantly suppresses mining-induced ground deformation. Compared to conventional longwall mining at the adjacent 5-210 face, the roof cutting approach at 5-200 resulted in notably narrower (0.05–0.2 m) and shallower (0.1–0.4 m) surface cracks, reflecting effective attenuation of stress transmission through the overburden. Taken together, the proposed roof cutting and pressure relief strategy enables both stress decoupling and energy dissipation in the overlying strata, while enhancing roadway stability, reducing support demand, and mitigating surface environmental impact. This work provides quantitative validation and engineering guidance for intelligent and low-impact coal mining practices in high-stress, geologically complex settings. Full article

(This article belongs to the Section Process Control and Monitoring)

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22 pages, 9292 KB

Open AccessArticle

Mechanisms and Potential Assessment of CO₂ Sequestration in the Baijiahai Uplift, Junggar Basin

by Xiaohui Wang, Wen Zhang, Qun Wang, Kepeng Wang, Saisai Qin and Tianyu Wang

Processes 2025, 13(8), 2648; https://doi.org/10.3390/pr13082648 - 21 Aug 2025

Viewed by 446

Abstract

To reduce CO₂ emissions, CO₂ geological storage is recognized as an effective approach to decrease atmospheric carbon concentration. Sequestration in deep saline aquifers has become a research focus. However, the physicochemical property changes in saline formations induced by CO₂ injection [...] Read more.

To reduce CO₂ emissions, CO₂ geological storage is recognized as an effective approach to decrease atmospheric carbon concentration. Sequestration in deep saline aquifers has become a research focus. However, the physicochemical property changes in saline formations induced by CO₂ injection remain unclear, making it difficult to assess their CO₂ storage potential. This study focuses on saline aquifers within the Jurassic Badaowan formation (J₁b), Sangonghe formation (J₁s), and Cretaceous Tugulu Group (K₁tg) of the Baijiahai Uplift in the Junggar Basin. An integrated methodology combining laboratory experiments—including CO₂ static immersion tests, dynamic displacement tests, X-ray diffraction (XRD), mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR) measurements, and mechanical testing—with CMG-based numerical modeling was employed to analyze CO₂ storage mechanisms and evaluate storage potential. The results show that after CO₂ immersion, extensive dissolution of calcite in J₁s, clay swelling/cementation in J₁b, and extensive dissolution of calcite in K₁tg all lead to increased porosity and permeability, with the J₁b formation exhibiting superior CO₂ storage capacity, the highest MICP-derived porosity, and the greatest NMR-measured porosity among the three formations. Numerical simulations further confirmed J₁b’s leading sequestration volume. Based on integrated experimental and simulation results, the J₁b formation is identified as the optimal reservoir for CO₂ storage. However, to manage potential mechanical instability during real-world injection scenarios, injection pressures and rates should be carefully controlled and continuously monitored to avoid formation fracturing and ensure long-term storage security. This study provides a reference for implementing saline aquifer CCUS projects. Full article

(This article belongs to the Section Energy Systems)

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20 pages, 3871 KB

Open AccessArticle

Influence of Ammonium on the Adsorption and Desorption of Heavy Metals in Natural Zeolites

by Luca Marco Ofiera and Christian Kazner

Processes 2025, 13(8), 2647; https://doi.org/10.3390/pr13082647 - 21 Aug 2025

Viewed by 1271

Abstract

Natural zeolites have gained attention as low-cost adsorbents for the removal of heavy metals (HMs) from wastewater. However, their performance can be compromised by the presence of competing cations such as ammonium (NH₄⁺). This study investigated the competitive adsorption and [...] Read more.

Natural zeolites have gained attention as low-cost adsorbents for the removal of heavy metals (HMs) from wastewater. However, their performance can be compromised by the presence of competing cations such as ammonium (NH₄⁺). This study investigated the competitive adsorption and desorption dynamics of NH₄⁺ and six HMs (Cd, Cr, Cu, Ni, Pb, and Zn) on two natural zeolites. Batch and column experiments using synthetic wastewater were conducted to evaluate the effects of different NH₄⁺ concentrations, pH, and particle size on HM removal efficiency and desorption effects. Results showed that increasing NH₄⁺ concentrations significantly reduce HM adsorption, with total capacity decreasing by ~45% at 100 mg/L NH₄-N in kinetic tests. Adsorption isotherms of the HM mixture for both zeolite types followed a clear sigmoidal trend, which was captured well by the Hill model (R² = 0.99), with loading rates up to 56.14 mg/g. Pb consistently exhibited the highest affinity for zeolites, while Cd, Cr, Ni, and Zn were most affected by NH₄⁺ competition in the column tests. Desorption tests confirmed that NH₄⁺ rapidly re-mobilises adsorbed metals, in particular Cd, Cu, and Zn. Slightly acidic to neutral pH conditions were optimal for minimising HM remobilisation. These findings underscore the need to consider competitive interactions and operational conditions when applying natural zeolites for HM removal, especially in ammonium-rich environments such constructed wetlands, soil filters, or other decentralised applications. Full article

(This article belongs to the Special Issue Innovation of Heavy Metal Adsorption Process)

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13 pages, 3072 KB

Open AccessArticle

Effects of Biodiesel–Ethanol–Graphene Droplet Volume and Graphene Content on Microexplosion: Distribution, Velocity and Acceleration of Secondary Droplets

by Jing Shi, Changhao Wang, Wei Zhang and Kesheng Meng

Processes 2025, 13(8), 2646; https://doi.org/10.3390/pr13082646 - 21 Aug 2025

Viewed by 521

Abstract

Under the continuous tightening of global carbon emission policies, the search for sustainable low-emission energy sources is of great significance to reduce the reliance on the use of fossil fuels and to save energy and reduce emissions. Biodiesel–ethanol–graphene mixed fuel has high combustion [...] Read more.

Under the continuous tightening of global carbon emission policies, the search for sustainable low-emission energy sources is of great significance to reduce the reliance on the use of fossil fuels and to save energy and reduce emissions. Biodiesel–ethanol–graphene mixed fuel has high combustion efficiency and low emission characteristics, and an in-depth study of its evaporation and microexplosion characteristics during the heating process can help to better understand the characteristics of this fuel. In this paper, the evaporation, microexplosion, sub-droplet distribution and kinematic properties of biodiesel–ethanol–graphene droplets under different temperatures, volumes and mixing ratios were investigated by simulating the air atmosphere using a modified tube furnace experimental platform. It was found that the BD50E50 (1%G) droplet produced a weak microexplosion under 600 °C, and three secondary droplets were formed, with the largest secondary droplet area reaching 5.28 mm². The BD50E50 (1%G) droplet produced strong microexplosion under 800 °C conditions, and 10 secondary droplets were formed, with the largest secondary droplet area of 3.02 mm². Different intensities of microexplosion and ejection phenomena produced by the biodiesel–ethanol–graphene droplets during the heating process were found, and it was found that the temperature and droplet volume determine whether the microexplosion of the mixed droplets can occur or not, while the intensity of the microexplosion determines the number of secondary droplets and the speed of movement. Additionally, the velocity and acceleration of secondary droplets produced by ejection were significantly greater than those produced by microexplosion. These studies provide a theoretical basis for the application of this fuel. Full article

(This article belongs to the Special Issue Advances in Engineering Thermodynamics and Numerical Simulation)

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15 pages, 7918 KB

Open AccessArticle

Scale Deposition During Water Flooding and the Effect on Reservoir Performance

by Adaobi B. Irogbele, Bilal A. Ibrahim, Derrick Adjei, Vincent N. B. Amponsah, Racha Trabelsi, Haithem Trabelsi and Fathi Boukadi

Processes 2025, 13(8), 2645; https://doi.org/10.3390/pr13082645 - 20 Aug 2025

Viewed by 711

Abstract

Scale deposition during waterflooding, driven by the incompatibility between injected seawater and formation of water, poses significant challenges to reservoir performance. This study examines the mechanisms of inorganic scale formation and assesses its impact on productivity index, permeability, and pressure dynamics using the [...] Read more.

Scale deposition during waterflooding, driven by the incompatibility between injected seawater and formation of water, poses significant challenges to reservoir performance. This study examines the mechanisms of inorganic scale formation and assesses its impact on productivity index, permeability, and pressure dynamics using the ECLIPSE simulator. A five-layered reservoir model with one injector and one producer (spaced 700 feet apart) was simulated under varying seawater injection rates of 1000, 3000, and 5000 stock tank barrels per day (stb/day). The results revealed rapid water breakthrough and escalating water cuts (34–38%) across scenarios, with scale deposition concentrated in layers 3 and 4, reducing permeability by up to 47% and productivity index by 50%. Layer 3 exhibited a threefold higher scaling due to the intense mixing of seawater and the formation of water. The study highlights the necessity of sulfate removal, alternative water sources, well repositioning, and preemptive scale inhibition to minimize reservoir damage caused by scale-induced permeability impairment. Full article

(This article belongs to the Special Issue Unconventional Energy, Clean Energy and Carbon Sequestration: Progress in Technology)

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28 pages, 11980 KB

Open AccessArticle

Gas Sources and Productivity-Influencing Factors of Matrix Reservoirs in Xujiahe Formation—A Case Study of Xin 8-5H Well and Xinsheng 204-1H Well

by Weijie Miao, Xingwen Wang, Wen Zhang, Ling Qiu, Qianli Lu and Xinwei Gong

Processes 2025, 13(8), 2644; https://doi.org/10.3390/pr13082644 - 20 Aug 2025

Viewed by 504

Abstract

The tight sandstone gas reservoirs of the Xujiahe Formation are critical targets for tight gas exploration and development in the Sichuan Basin. While Class I reservoirs have been successfully developed using staged volume fracturing technology, efforts are being increasingly directed toward Class II [...] Read more.

The tight sandstone gas reservoirs of the Xujiahe Formation are critical targets for tight gas exploration and development in the Sichuan Basin. While Class I reservoirs have been successfully developed using staged volume fracturing technology, efforts are being increasingly directed toward Class II and III matrix-type blocks. These reservoirs are characterized by a low permeability, high geo-stress differentials, strong heterogeneity, and limited fracture development. These properties result in several challenges, including ambiguous gas production sources, low reservoir utilization rates, significant variability in horizontal well performance, and rapid early-stage production decline—all of which hinder the effective development of matrix-type reservoirs. This study examines two representative fractured wells, Xin 8-5H and Xinsheng 204-1H, located in Class II and III blocks of the Xujiahe Formation gas reservoir. To identify gas production sources, we establish full-fracturing-section productivity models. Furthermore, accounting for variations in geological characteristics, we develop distinct productivity models for three key zones, the matrix area, fracture area, and fault area, to evaluate the productivity controls. The findings reveal that well Xin 8-5H primarily produces gas from the matrix and fault zones, whereas well Xinsheng 204-1H derives most of its production from the matrix and natural fractures. In matrix-dominated zones, generating complex fracture networks enhances productivity. An optimal cluster spacing of approximately 14 m ensures broad pressure sweep coverage while maintaining effective inter-cluster fracture connectivity. Additionally, natural fractures in the Xu-2 matrix reservoirs play a vital role in fluid communication. To maximize reservoir contact, well trajectories should be designed such that natural fractures are oriented either parallel or perpendicular to the wellbore, thereby improving lateral and vertical development. Near fault zones, adjusting cluster spacing to 14–25 m—while keeping the distance between faults and fracturing stages below 50 m—effectively connects faults and substantially increases production. This study introduces a systematic methodology for identifying gas sources in matrix reservoirs and optimizes key productivity-influencing parameters. The results provide both theoretical insights and practical strategies for the efficient development of Xu-2 matrix reservoirs. Full article

(This article belongs to the Section Energy Systems)

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11 pages, 852 KB

Open AccessArticle

Furthering the Application of a Low-Moisture Anhydrous Ammonia Pretreatment of Corn Stover

by Ming-Hsun Cheng and Kurt A. Rosentrater

Processes 2025, 13(8), 2643; https://doi.org/10.3390/pr13082643 - 20 Aug 2025

Viewed by 467

Abstract

The use of an ammonia fiber expansion pretreatment using low-moisture anhydrous ammonia (LMAA) is a promising strategy for biomass deconstruction, with significant effects on depolymerizing lignin and hemicellulose. An LMAA pretreatment provides several advantages, including compatibility with the high-biomass loading of solids, efficient [...] Read more.

The use of an ammonia fiber expansion pretreatment using low-moisture anhydrous ammonia (LMAA) is a promising strategy for biomass deconstruction, with significant effects on depolymerizing lignin and hemicellulose. An LMAA pretreatment provides several advantages, including compatibility with the high-biomass loading of solids, efficient ammonia recovery, and scalability for industrial operations. In this study, the reactor was revisited and optimized to improve glucan digestibility from corn stover through enzymatic hydrolysis, building on our previous findings that identified limitations in ammonia distribution. The effects of the biomass particle size, the reaction time, and their interaction on glucose yields were investigated to determine their influence on the subsequent enzymatic hydrolysis kinetics. The best glucose yield of 83% was achieved using an LMAA pretreatment of biomass with a 0.5 mm particle size, representing an improvement of approximately 5% compared to biomass with a 1 mm particle size. Additionally, reactor optimization led to a 22% improvement in the glucose yield compared to the previous reactor configuration. According to the results of the reaction kinetics fitting, the enzymatic hydrolysis data indicated that the reaction followed a pseudo-first-order model. Full article

(This article belongs to the Special Issue Advances in Solid Waste Treatment and Design (2nd Edition))

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22 pages, 5520 KB

Open AccessArticle

Comparative Study of Variable-Flow Gas Injection Patterns on CH₄ Diffusion Dynamics: Experimental Insights into Enhanced Coalbed Methane Recovery

by Jingang Wu, Haoran Gong, Guang Zhang, Zhen Lou and Jiaying Hu

Processes 2025, 13(8), 2642; https://doi.org/10.3390/pr13082642 - 20 Aug 2025

Viewed by 494

Abstract

Variable-flow displacement has been effectively used to enhance oil recovery; however, it has rarely been investigated for coalbed methane production, and the CH₄ diffusion laws in this process are not clear. In this paper, we carried out a study on the CH [...] Read more.

Variable-flow displacement has been effectively used to enhance oil recovery; however, it has rarely been investigated for coalbed methane production, and the CH₄ diffusion laws in this process are not clear. In this paper, we carried out a study on the CH₄ diffusion law in the bidirectional diffusion process displaced by variable-flow gas injection. The emission and desorption quantity of CH₄ under variable-flow gas injection, the displacement effect under the principle of equal time and quantity, and the applicability of the CH₄ diffusion model for the bidirectional diffusion process were analyzed. The results indicate that the variable-flow injection modes emit more CH₄ compared to constant flow injection. The CH₄ emission and desorption quantities for each injection mode are as follows: step-changed > sinusoidal-changed > constant flow. Secondly, the order of CH₄ emission and desorption quantity in each gas injection mode is as follows: step-changed > sinusoidal-changed > constant flow. When CO₂ is the injection gas source, the outlet CH₄ emission and desorption quantity are larger than N₂ injection. Thirdly, through the analysis of the principle of equal time and equal quantity, the variable-flow injection modes consume less gas for each volume of emitted CH₄, resulting in a more effective displacement. Finally, the diffusion fitting effect of the bidisperse model for CH₄ in the bidirectional diffusion process is better than that of the unipore model, and the bidisperse diffusion model can better fit the m_t/m_∞ curve of CH₄ diffusion during the variable-flow gas injection replacement process. Full article

(This article belongs to the Section Energy Systems)

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19 pages, 5642 KB

Open AccessArticle

Effect of Back Wear-Ring Clearance on the Internal Flow Noise in a Centrifugal Pump

by Pengxuan Zhou, Minggao Tan, Xianfang Wu, Houlin Liu and Denghao Wu

Processes 2025, 13(8), 2641; https://doi.org/10.3390/pr13082641 - 20 Aug 2025

Viewed by 730

Abstract

To investigate the effects of clearance variations induced by back wear ring wear on internal flow and noise within centrifugal pumps at the design flow rate (Q_o = 25 m³/h), a combined Computational Fluid Dynamics (CFD) and Acoustic Finite [...] Read more.

To investigate the effects of clearance variations induced by back wear ring wear on internal flow and noise within centrifugal pumps at the design flow rate (Q_o = 25 m³/h), a combined Computational Fluid Dynamics (CFD) and Acoustic Finite Element Method (FEM) approach was employed. The SST-SAS turbulence model and Lighthill’s acoustic analogy, were applied to simulate the internal flow and acoustic fields, respectively, across four different clearance values. The impact laws of various back wear-ring clearances on flow-induced noise were analyzed. The results indicate that the head and efficiency of the centrifugal pump gradually decrease with the increase in the back wear-ring clearance. When the clearance reaches 1.05 mm, the head drops by 4.35% and the efficiency decreases by 14.86%. The radial force on the impeller decreases, while the axial force increases and its direction reverses by 180 degrees. The acoustic source strength at the rotor–stator interface, near the volute tongue, and at the outlet of the back wear ring increases with larger clearance; furthermore, high-sound-source regions expand around the balance holes and near the impeller suction side. The dominant SPL frequency for all clearance cases was the blade passing frequency (BPF). As clearance increases, the overall SPL curve shifts upwards; however, the variation gradient decreases noticeably when the clearance exceeds 0.75 mm. The overall internal SPL increases, with the total SPL under 1.05 mm being 1.8% higher than that under 0.15 mm. In total, the optimal back ring clearance is 0.45 mm, which achieves a 38% noise reduction while maintaining a 97.9% head capacity. Full article

(This article belongs to the Section Process Control and Monitoring)

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20 pages, 1289 KB

Open AccessArticle

Influence of Thermal Treatments on Textural and Rheological Properties of Different Types of Meatballs

by Luiza-Andreea Tănase (Butnariu), Doina-Georgeta Andronoiu, Oana-Viorela Nistor, Gabriel-Dănuț Mocanu, Livia Pătrașcu and Elisabeta Botez

Processes 2025, 13(8), 2640; https://doi.org/10.3390/pr13082640 - 20 Aug 2025

Viewed by 712

Abstract

Ready-to-eat products are very popular and controversial due to their microbial safety. The main processing steps in obtaining a safe, edible product is heat treatment. The traditional manufacturing of meatballs, which conducts unhealthy compounds related to deep-fat-fried foods like the oil oxidation of [...] Read more.

Ready-to-eat products are very popular and controversial due to their microbial safety. The main processing steps in obtaining a safe, edible product is heat treatment. The traditional manufacturing of meatballs, which conducts unhealthy compounds related to deep-fat-fried foods like the oil oxidation of harmful substances and polycyclic aromatic hydrocarbons, has been replaced with baking (180 °C) and steaming (94 °C). The addition of aqueous extract from two herbs, lemon balm (Melissa officinalis L.) or wild thyme (Thymus serpyllum L.), has led to twelve variants of meatballs, obtained from the tenderloin of three different animal species (pork, turkey, and beef). During processing, the food components go through conformational changes that affect the texture of the final product. In this study, differential scanning calorimetry for detecting and characterizing the thermal changes in meatballs was used. In addition, the influence of heat treatments on the textural and rheological parameters of meatballs was evaluated using instrumental methods. The cooking yield registered values of 61.21 ± 0.25% for steamed beef samples and 81.36 ± 0.86% for steamed turkey samples. The latest samples also showed the lowest firmness value, 3.41 ± 0.79 N. In this study, the addition of aqueous extracts did not considerably affect the texture and rheological behavior, which were influenced mainly by the heat treatment and meat type. Generally, steaming determined a firmer texture compared to baking. Full article

(This article belongs to the Section Food Process Engineering)

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24 pages, 9679 KB

Open AccessArticle

Mechanisms and Optimization of Critical Parameters Governing Solid-Phase Transport in Jet Pumps for Vacuum Sand Cleanout

by Xia Jia, Hualin Liao, Lei Zhang, Yan Zhang and Jiawei Liu

Processes 2025, 13(8), 2639; https://doi.org/10.3390/pr13082639 - 20 Aug 2025

Viewed by 548

Abstract

This paper addresses the critical challenge of insufficient solid-phase suction capacity in jet pumps during vacuum sand cleanout operations for low-pressure oil and gas wells. Through integrated numerical simulations validated by experimental measurements with under 15% error, a kind of nonlinear interaction mechanism [...] Read more.

This paper addresses the critical challenge of insufficient solid-phase suction capacity in jet pumps during vacuum sand cleanout operations for low-pressure oil and gas wells. Through integrated numerical simulations validated by experimental measurements with under 15% error, a kind of nonlinear interaction mechanism among key operational and solid-phase parameters is revealed in this paper. The results demonstrate that due to intensified turbulent dissipation, particle diameters exceeding 0.5 mm will lead to a significant decrease in pump efficiency, while an increase in solid volume fraction can improve the solid transport rate but will reduce the energy conversion efficiency. Working pressure optimization shows that the pump efficiency will reach its maximum when the work pressure is 5 MPa, while if it is 8 MPa, the solid transport capacity will be increased by 116%. A discharge pressure exceeding 2.5 MPa will reduce the suction pressure difference and disrupt solid phase transport. A novel dual-metric framework considering the solid transport rate and pump efficiency is put forward in this paper, which includes limiting the particle diameter to 0.5 mm or less, maintaining a solid volume fraction below 30%, and keeping the working pressure between 5 and 8 MPa and the discharge pressure at 2.5 MPa or lower. This method can increase the sand removal efficiency to over 30% while minimizing energy loss, providing a validated theoretical basis for sustainable wellbore repair in depleted oil reservoirs. Full article

(This article belongs to the Topic Advanced Heat and Mass Transfer Technologies, 2nd Edition)

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