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 13.7 days after submission; acceptance to publication is undertaken in 2.8 days (median values for papers published in this journal in the second half of 2023).
- 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:
3.5 (2022);
5-Year Impact Factor:
3.4 (2022)
Latest Articles
Electrochemical Polishing Method for Titanium Alloys with a Microgroove Structure
Processes 2024, 12(6), 1114; https://doi.org/10.3390/pr12061114 (registering DOI) - 28 May 2024
Abstract
TI–6AL–4V alloys are widely used in various fields owing to their excellent corrosion resistance, high-temperature resistance, and low-temperature toughness. Herein, a microgroove fixture was used to simulate the microgrooves in a titanium alloy with different aspect ratios to study the influence of the
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TI–6AL–4V alloys are widely used in various fields owing to their excellent corrosion resistance, high-temperature resistance, and low-temperature toughness. Herein, a microgroove fixture was used to simulate the microgrooves in a titanium alloy with different aspect ratios to study the influence of the electrolyte flow rate on the polishing effect. The optimization of the electrochemical polishing parameters was conducted using experiments and simulations. The effects of process parameters, such as the concentration of sodium chloride (NaCl) and zinc chloride (ZnCl2), polishing time, and processing voltage, on the quality of the post-polished surface were studied. Experiments were conducted on microgrooves with different aspect ratios under the optimized polishing process parameters. Changes in the surface elements of the microgrooves after polishing were detected. The experimental results indicated that the optimal electrochemical polishing solution flow rate, NaCl concentration, ZnCl2 concentration, polishing time, and processing voltage were 0.2 m/s, 4.0 wt.%, 0.4 wt.%, 8 min, and 90 V, respectively. After 8 min of electrochemical polishing, a TiO2 passivation film was formed on the surface of the microgroove. The surface roughness of the notch and bottom of the microgroove decreased from 250 nm to below 40 nm, with a minimum of 24.5 nm.
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(This article belongs to the Section Particle Processes)
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Study on the Evolution of Physicochemical Properties of Carbon Black at Different Regeneration Stages of Diesel Particulate Filters Regenerated by Non-Thermal Plasma
by
Yong Luo, Yunxi Shi, Kaiqi Zhuang, Ruirui Ji, Xulong Chen, Yankang Huang, Zhe Wang, Yixi Cai and Xiaohua Li
Processes 2024, 12(6), 1113; https://doi.org/10.3390/pr12061113 (registering DOI) - 28 May 2024
Abstract
As a new type of aftertreatment technology, non-thermal plasma (NTP) can effectively decompose the particulate matter (PM) deposited in diesel particulate filters (DPFs). In this paper, a regeneration test of a DPF loaded with carbon black was carried out using an NTP injection
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As a new type of aftertreatment technology, non-thermal plasma (NTP) can effectively decompose the particulate matter (PM) deposited in diesel particulate filters (DPFs). In this paper, a regeneration test of a DPF loaded with carbon black was carried out using an NTP injection system, and the changes of oxidative activity, elemental content, and occurrence state, microstructure and graphitization degree of carbon black were analyzed to reveal the evolution of the physicochemical properties of carbon black at different regeneration stages of the DPF regenerated by NTP. As the regeneration stage of the DPF advanced, Ti, Tmax, and Te of the carbon black at the bottom of the DPF decreased, which were higher than those at the regeneration interface. After the NTP reaction, the proportion of C element decreased to less than 80%, while the proportion of O element increased to more than 20%; C-O was converted to C=O and the relative content of C=O increased. The average microcrystalline length and average spacing decreased, while the average microcrystalline curvature increased. The ID1/IG (relative peak intensities) of carbon black samples decreased from 3.31 to 3.10, and the R3 (relative peak intensities, R3 = ID3/(IG+ ID2 + ID3)) increased from 0.41 to 0.58. The content of carbon clusters had a great influence on the disorder of the microcrystalline structure, so the graphitization degree of carbon black decreased and the oxidation activity increased.
Full article
(This article belongs to the Special Issue Clean Combustion and Emission in Vehicle Power System, 2nd Edition)
Open AccessArticle
Polyhydroxyalkanoate Production by Actinobacterial Isolates in Lignocellulosic Hydrolysate
by
Dzunani Mabasa, Amrita Ranjan, Marilize Le Roes-Hill, Thandekile Mthethwa and Pamela Jean Welz
Processes 2024, 12(6), 1112; https://doi.org/10.3390/pr12061112 (registering DOI) - 28 May 2024
Abstract
Polyhydroxyalkanoate (PHA) polymers are environmentally friendly alternatives to conventional plastics. In support of a circular bioeconomy, they can be produced by growing microbial strains in waste materials, including lignocellulosic biomass, such as Canola fines (straw). In this study, PHA and polyhydroxybutyrate (PHB) production
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Polyhydroxyalkanoate (PHA) polymers are environmentally friendly alternatives to conventional plastics. In support of a circular bioeconomy, they can be produced by growing microbial strains in waste materials, including lignocellulosic biomass, such as Canola fines (straw). In this study, PHA and polyhydroxybutyrate (PHB) production by a selection of seven wild-type actinobacterial strains, including three strains of Gordonia species, were assessed. When grown in defined media and hydrolysates of Canola fines, the highest amounts of PHB were produced by Nocardia gamkensis CZH20T (0.0476 mg/mL) and Gordonia lacunae BS2T (0.0479 mg/mL), respectively. Six strains exhibited a substrate preference for cellobiose over glucose, xylose, and arabinose in the hydrolysates. Analysis of Fourier transform infrared spectra indicated that the strains produced co-polymers of short- and medium-chain-length PHAs. None of the core phaABC genes were found on defined operons in the genomes of the top PHB-producing strains (all Gordonia strains, N. gamkensis CZH20T, and Streptomyces sp. strain HMC19). The Gordonia strains all harbored three phaA genes, a single phaB gene, and, with the exception of strain BG1.3 (with two predicted phaC genes), a single phaC gene. Predictive analyses of the proteins likely to be translated from the phaC genes revealed PhaC proteins of 37.7–39.2 kDa from Gordonia sp. strain BG1.3, G. lacunae BS2T, and N. gamkensis CZH20T; PhaC proteins of 106.5–107 kDa from Gordonia sp. strain JC51; and the second PhaC from Gordonia sp. strain BG1.3 and N. gamkensis CZH20T, possibly representing a new class of PHA synthases.
Full article
(This article belongs to the Special Issue Advances in Biomass Pretreatment and Conversion Processes)
Open AccessReview
Recent Advances in Biochar: Synthesis Techniques, Properties, Applications, and Hydrogen Production
by
Evan D. Visser, Ntalane S. Seroka and Lindiwe Khotseng
Processes 2024, 12(6), 1111; https://doi.org/10.3390/pr12061111 - 28 May 2024
Abstract
The field of material sciences has evolved vastly in the last two decades, largely due to the discovery of carbon nanomaterials such as graphene and its derivatives. Although they offer positive characteristics, the cost of production and material processing of these carbon nanomaterials
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The field of material sciences has evolved vastly in the last two decades, largely due to the discovery of carbon nanomaterials such as graphene and its derivatives. Although they offer positive characteristics, the cost of production and material processing of these carbon nanomaterials has limited their application. However, scientists have started searching for cheaper and more environmentally friendly alternatives. Biochar, a carbonaceous material derived from biowaste, is the most viable alternative, as it offers characteristics on par with traditional carbon nanomaterials. This review will discuss the production of biochar from biomass, methods of production, the effects various conditions have on the production of biochar, biomass selection, current biochar applications, and the potential biochar has to produce hydrogen as an energy carrier.
Full article
(This article belongs to the Special Issue Green and Sustainable Chemistry of Waste Conversion in Circular Economy: Challenges and Perspectives)
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Open AccessArticle
Organic Waste for Bioelectricity Generation in Microbial Fuel Cells: Effects of Feed Physicochemical Characteristics
by
Shubham Arun Parwate, Wenchao Xue, Thammarat Koottatep and Abdul Salam
Processes 2024, 12(6), 1110; https://doi.org/10.3390/pr12061110 - 28 May 2024
Abstract
Food waste (FW), piggery waste (PW), and activated sludge (AS) were investigated as potential organic feeds for bioelectricity generation in laboratory-scale microbial fuel cells (MFCs). The MFCs fed by FW gained the highest maximum power density at 7.25 W/m3, followed by
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Food waste (FW), piggery waste (PW), and activated sludge (AS) were investigated as potential organic feeds for bioelectricity generation in laboratory-scale microbial fuel cells (MFCs). The MFCs fed by FW gained the highest maximum power density at 7.25 W/m3, followed by those fed by PW at 3.86 W/m3 and AS at 1.54 W/m3. The tCOD removal in the FW-, PW-, and AS-MFCs reached 76.9%, 63.9%, and 55.22%, respectively, within a 30-day retention time. Food waste, which resulted in the highest power density and tCOD removal, was selected for a series of following tests to investigate the effects of some physicochemical properties of organic feed on the performance of MFCs. The effect of feed particle size was tested with three controlled size ranges (i.e., 3, 1, and <1 mm) in MFCs. A smaller feed particle size provided a higher power density of 7.25 W/m3 and a tCOD removal of 76.9% compared to the MFCs fed with organic waste with a larger particle size. An increment in feed moisture from 70% to 90% improved the maximum power density from 7.2 to 8.5 W/m3, with a 17.5% enhancement, and improved the tCOD removal from 75.8% to 83.3%, with a 10.0% enhancement. A moderate C/N ratio of approximately 30/1 maximized the power density and COD removal (7.25 W/m3 and 81.73%) in the MFCs compared to C/N ratios of 20/1 (4.0 W/m3 and 64.14%) and 45/1 (4.38 W/m3 and 71.34%).
Full article
(This article belongs to the Special Issue Advances in Value-Added Products from Waste)
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Open AccessArticle
Modifications on the Processing Parameters of Traditional Pineapple Slices by Stabilized Sound Pressure of Multiple Frequency Ultrasonic-Assisted Osmotic Dehydration
by
Yu-Wen Lin, Yueh-An Yao, Da-Wei Huang, Chung-Jen Chen and Ping-Hsiu Huang
Processes 2024, 12(6), 1109; https://doi.org/10.3390/pr12061109 - 28 May 2024
Abstract
This study investigated the practical feasibility of synergistically and optimally applying ultrasound-assisted osmotic dehydration (UAOD) practices for the pineapple slice picking process (in sugar osmotic solution), with potential implications for improving current practices. This study was carried out to evaluate the effects of
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This study investigated the practical feasibility of synergistically and optimally applying ultrasound-assisted osmotic dehydration (UAOD) practices for the pineapple slice picking process (in sugar osmotic solution), with potential implications for improving current practices. This study was carried out to evaluate the effects of different treatment conditions of single (40 and 80 kHz)/multiple (40/80 kHz) frequencies, output powers (300, 450, and 600 W), and treatment time (5–40 min) at 30, 45, and 60 °Brix applied, respectively, on the pineapple slices picking process. The sound pressure of the UA was also measured to confirm that it provided the corresponding effect stably under different conditions. The ideal UAOD operating condition for pineapple slices is a 45 °Brix sugar osmotic solution, with frequency multiplexing at 40/80 kHz and an output power of 450 W for 25 min, which yields the optimal solids gain (SG) rate of 7.58%. The above results of this study indicated that UAOD could improve the accelerated quality transfer of pineapple slices and enhance the final product quality, thereby increasing the efficiency of the dehydration process and saving processing costs and time.
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(This article belongs to the Special Issue Drying Kinetics and Quality Control in Food Processing, 2nd Edition)
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Open AccessArticle
Target Tracking Two Degrees of Freedom State Feedback Control for Continuous Flow Microfluidic Chips Temperature Controller
by
Yuqi Jiang, Yang Liu, Yuxiong Xue, Wei Jiang and Seiji Hashimoto
Processes 2024, 12(6), 1108; https://doi.org/10.3390/pr12061108 - 28 May 2024
Abstract
Microfluidic chips represent a cutting-edge technology for manipulating fluids within micrometer-scale spaces and are gradually becoming a new favorite platform in life science research. Precise and fast zonal temperature control is essential for accelerating biological experiments. However, current multi-channel temperature controllers typically rely
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Microfluidic chips represent a cutting-edge technology for manipulating fluids within micrometer-scale spaces and are gradually becoming a new favorite platform in life science research. Precise and fast zonal temperature control is essential for accelerating biological experiments. However, current multi-channel temperature controllers typically rely on multiple channel sets to achieve single set-point control, which results in discrepancies between the fluid temperature distribution and sensor temperature due to the distributed temperature field in the fluid channel. To estimate the actual temperature and implement gradient temperature control, this paper introduces an extension of the target tracking (TT) two degrees of freedom (2DOF) state feedback control (SFC) method, followed by a presentation of simulation and experimental results. Through comparisons with an enhanced PID system in both simulation and experimentation, the paper demonstrates an 8.96% reduction in the maximum temperature difference across different regions and a 27.89% decrease in the time taken to reach various temperatures. This solution effectively addresses the existing challenges in temperature control for microfluidic chips, offering a more precise and stable control within the desired temperature range.
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(This article belongs to the Section Advanced Digital and Other Processes)
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Open AccessArticle
Kinetics of Vegetable Oils (Rice Bran, Sunflower Seed, and Soybean) Extracted by Pressurized Liquid Extraction in Intermittent Process
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Paulo Rodolfo Ramos, Joyce Sponchiado, João Victor Febrônio Echenique, Gustavo César Dacanal and Alessandra Lopes de Oliveira
Processes 2024, 12(6), 1107; https://doi.org/10.3390/pr12061107 - 28 May 2024
Abstract
The research focuses on optimizing vegetable oil production processes for human consumption, emphasizing green and efficient extraction methods using renewable solvents with minimal toxic residues. Pressurized liquid extraction (PLE), especially with ethanol, is studied for its efficiency and low solvent usage in intermittent
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The research focuses on optimizing vegetable oil production processes for human consumption, emphasizing green and efficient extraction methods using renewable solvents with minimal toxic residues. Pressurized liquid extraction (PLE), especially with ethanol, is studied for its efficiency and low solvent usage in intermittent processes. By evaluating extraction parameters and kinetics, the study aims to determine optimal conditions for higher extraction rates and yields, providing insights into production costs and other factors. Specifically, the research examines the behavior of extraction kinetics for vegetable oils like rice bran, sunflower seeds, and rolled soybeans. It also seeks to determine mass diffusivity in semi-continuous processes and to model PLE in intermittent processes using Fick’s Law and Mathematica Wolfram Software v11.2. The effective diffusivity (Deff) for rice bran oil in pressurized ethanol varied between 13.09 and 15.70 × 10−12 m2/s, and the Deff value of sunflower seed oil was between 8.10 and 12.60 × 10−12 m2/s. For rolled soybean oil, the Deff value ranged from 17.25 to 31.29 × 10−12 m2/s. The mass diffusivity values of vegetable oils in pressurized ethanol remained within the same order of magnitude. The mass diffusivity for PLE in an intermittent process presented values of 5.97 × 10−12 m2/s for rice bran oil with 3 extraction cycles. The Deff value for sunflower seed oil in pressurized ethanol was 1.38 × 10−12 m2/s, with 4 cycles, and for rolled soybeans, the Deff value was 1.77 × 10−12 m2/s in 3 cycles. The Deff value found in the intermittent extraction process was lower than that in the semi-continuous process. The total solvent renewal in the semi-continuous extraction process significantly impacted the diffusivity values for all extracted oils, as this process utilizes much more solvent compared to the intermittent process for all matrices studied. Various factors, including geometry, average particle diameter, extraction temperature, and rinse solvent volume, can affect the differences in curve behavior between the semi-continuous and intermittent processes. Despite these factors, the intermittent process is considered more viable for implementation due to its favorable economic and environmental characteristics, primarily because it requires a much smaller amount of solvent.
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(This article belongs to the Special Issue Separation and Extraction Techniques in Food Processing and Analysis)
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Open AccessArticle
An Adaptive Discrete Integral Terminal Sliding Mode Control Method for a Two-Joint Manipulator
by
Jianliang Xu, Zhen Sui, Wenduo Wang and Feng Xu
Processes 2024, 12(6), 1106; https://doi.org/10.3390/pr12061106 - 28 May 2024
Abstract
In response to the trajectory tracking control problem of manipulators under measurement disturbances, a novel multi-input multi-output discrete integral terminal sliding mode control scheme is proposed. Initially, this scheme establishes a dynamic model of a two-joint manipulator based on the Lagrangian dynamics analysis
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In response to the trajectory tracking control problem of manipulators under measurement disturbances, a novel multi-input multi-output discrete integral terminal sliding mode control scheme is proposed. Initially, this scheme establishes a dynamic model of a two-joint manipulator based on the Lagrangian dynamics analysis method. Subsequently, a discrete integral terminal sliding mode control law based on the dynamic model of the two joints is designed, incorporating delayed estimation of unknown disturbances and discretization errors in the manipulator system. To enhance the trajectory tracking accuracy of the control scheme and suppress the impact of sliding mode chattering on the manipulator system, an adaptive switching term is introduced into the discrete integral terminal sliding mode control law. The paper derives an adaptive discrete integral terminal sliding mode control scheme and provides stability proof for the proposed approach. Simulation experiments are conducted to compare the proposed adaptive discrete integral terminal sliding mode control scheme with classical discrete sliding mode control schemes and discrete integral terminal sliding mode control schemes. The simulation results demonstrate that the designed adaptive discrete integral terminal sliding mode control scheme maintains trajectory tracking errors within 0.004 radians for each joint of the manipulator, with minimal changes in control torque for each joint. The absolute integral of the control torque variations is calculated at , which is lower than other control schemes, thereby validating the effectiveness and superiority of the proposed approach.
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(This article belongs to the Section Automation Control Systems)
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Open AccessArticle
Approach to Chemical Process Transition Control via Regulatory Controllers with the Case of a Throughput Fluctuating Ethylene Column
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Dong Huang, Gang Liu, Kezhong Chen, Lizhi Liu and Jinlin Guo
Processes 2024, 12(6), 1105; https://doi.org/10.3390/pr12061105 - 28 May 2024
Abstract
For chemical processes, dynamic optimization is employed for process transition. On the basis of the multilayer control structure, the employment of dynamic optimization is affected by the regulatory control system. To avoid the adjustment of the regulatory control system, set-point optimization is proposed.
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For chemical processes, dynamic optimization is employed for process transition. On the basis of the multilayer control structure, the employment of dynamic optimization is affected by the regulatory control system. To avoid the adjustment of the regulatory control system, set-point optimization is proposed. For comparison, two types of optimization models, namely direct optimization and set-point optimization, are formulated. The superiority of set-point optimization is rigorously proven. By simulating the commercial process of a throughput-fluctuating ethylene column, the integrated absolute error and maximum deviation of product quality are reduced by more than 150% with set-point optimization. The results indicate that the approach to process transition via regulatory controllers not only avoids the insecurity caused by the switching of set-point controllers but also improves the optimization performance. In conclusion, the proposed optimization structure, namely set-point optimization, is operable and stable for commercial chemical process transitions.
Full article
(This article belongs to the Special Issue Continuous Production and Catalysis Optimization of Chemical Industry Processes)
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Open AccessReview
Recent Advancements in Photo-Bioreactors for Microalgae Cultivation: A Brief Overview
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Giannis Penloglou, Alexandros Pavlou and Costas Kiparissides
Processes 2024, 12(6), 1104; https://doi.org/10.3390/pr12061104 - 28 May 2024
Abstract
Inspired by the vast potential of microalgae in the bioeconomy and the numerous applications and benefits associated with their cultivation, a multitude of pilot- and industrial-scale microalgae production systems have been developed in recent years. Both open and closed cultivation systems have been
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Inspired by the vast potential of microalgae in the bioeconomy and the numerous applications and benefits associated with their cultivation, a multitude of pilot- and industrial-scale microalgae production systems have been developed in recent years. Both open and closed cultivation systems have been successfully utilized, with closed photo-bioreactors (PBRs) emerging as the most versatile option for various applications and products, enabling the implementation of advanced optimization strategies. Therefore, this short review provides a comprehensive overview of the different PBR configurations and their recent applications, primarily in large-scale but also in pilot- and laboratory-scale microalgae cultivation. A detailed discussion of the advantages, limitations, specific applications and recent advancements of each type of PBR is presented to aid researchers, engineers and industry stakeholders in selecting the most suitable PBR design for their specific goals and constraints. Moreover, this review highlights the major challenges impeding the full commercialization of microalgal products and forecasts future trends in the microalgae-based industry. The diverse potential applications of microalgae in various sectors, including biofuels, nutraceuticals, pharmaceuticals, agriculture and environmental remediation, underscore the versatility and significance of the relevant cultivation technologies. By offering valuable insights into the future commercial scale and trends of microalgal biotechnology, this work sheds light on the challenges and opportunities facing this burgeoning industry.
Full article
(This article belongs to the Special Issue Innovative Bioreactor Design and Advanced Optimization Strategies for Biorefineries and Bioprocessing)
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Open AccessArticle
Multi-Criteria Optimization of a Laboratory Top-Lit Updraft Gasifier in Order to Reduce Greenhouse Gases and Particulate Matter Emissions
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Alexandru-Polifron Chiriță, Ioan Pavel, Radu-Iulian Rădoi, Gabriela Matache, Gheorghe Șovăială and Ana-Maria Carla Popescu
Processes 2024, 12(6), 1103; https://doi.org/10.3390/pr12061103 - 27 May 2024
Abstract
Air pollution from combustion processes is harming human health and the environment. To mitigate this, one needs to adopt cleaner energy production methods, in particular, to optimize combustion systems in order to minimize pollutants and increase efficiency. Flue gas analysis and particulate matter
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Air pollution from combustion processes is harming human health and the environment. To mitigate this, one needs to adopt cleaner energy production methods, in particular, to optimize combustion systems in order to minimize pollutants and increase efficiency. Flue gas analysis and particulate matter (PM) monitoring, starting from the prototype phase, is crucial to minimize and regulate pollutant emissions. This article analyses the emissions of pollutants and particulate matter from a combustion test gasifier working on the Top-Lit Updraft (TLUD) principle in order to optimize functionality and reduce exhaust emissions. Three experiments were performed in which the primary (gasification) air flow rate (GA) was kept constant at 25 L/min, and the secondary (combustion) air flow rate (CA) was adjusted to obtain a CA/GA ratio of 2 (50 L/min), 3 (75 L/min), and 4 (100 L/min) respectively. Based on a multi-criterial analysis, the optimal CA/GA ratio for TLUD combustion is 3, offering a well-rounded performance in output temperatures, PM and greenhouse gases (GHG) emissions, and efficiency, while the CA/GA ratio of 4 has good PM and GHG emissions performance but lower efficiency, and the CA/GA ratio of 2 is the least favorable due to its poor performance in output temperatures, PM and GHG emissions.
Full article
(This article belongs to the Section Environmental and Green Processes)
Open AccessFeature PaperArticle
Sodium Hypochlorite Pentahydrate as a Chlorinating Reagent: Application to the Tandem Conversion of β,γ-Unsaturated Carboxylic Acids to α,β-Unsaturated Lactones
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Michio Iwaoka, Reo Shimada, Masaki Kuroda, Takehito Ikeda and Eduardo E. Alberto
Processes 2024, 12(6), 1102; https://doi.org/10.3390/pr12061102 - 27 May 2024
Abstract
Sodium hypochlorite pentahydrate (NaClO·5H2O, 1) has recently been employed in organic synthesis as an oxidant for alcohols, sulfides, glycols, etc. In most of these reactions, however, reagent 1 functions just as a simple oxidant, and the variations of the reactions
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Sodium hypochlorite pentahydrate (NaClO·5H2O, 1) has recently been employed in organic synthesis as an oxidant for alcohols, sulfides, glycols, etc. In most of these reactions, however, reagent 1 functions just as a simple oxidant, and the variations of the reactions have not been well explored. In this study, we report another useful and fascinating reaction, in which reagent 1 functions as a green chlorinating reagent toward β,γ-unsaturated carboxylic acid (2). When substrate 2 was stirred at room temperature with 1 (2 eq) in acetonitrile for 1 h, α,β-unsaturated lactone (3) was obtained in moderate yields (up to 62%). The same reaction proceeded in various organic and aqueous solvents as well. When excess reagent 1 was employed, lactone 3 was further oxidized to the corresponding epoxide (4) for some cases. The conversion is initiated by electrophilic attack of HOCl to the C=C bond of 2 to generate a chloronium ion intermediate, which is cyclized to β-chlorolactone (5) and then 3 through the elimination of HCl. The usefulness of 1 as a chlorinating reagent was further demonstrated in the electrophilic substitution of activated aromatic compounds.
Full article
(This article belongs to the Special Issue Advances and Prospects in Organic Synthesis)
Open AccessReview
Application of Additive Manufacturing in the Automobile Industry: A Mini Review
by
Jian Yang, Bo Li, Jian Liu, Zhantong Tu and Xin Wu
Processes 2024, 12(6), 1101; https://doi.org/10.3390/pr12061101 - 27 May 2024
Abstract
The automobile industry is recognized as one of the most influential sectors shaping global economies, societies, and individual lifestyles. Therefore, fierce competition among different companies is continuously undergoing, and special attention is focused on innovations to improve competitiveness. In the past several years,
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The automobile industry is recognized as one of the most influential sectors shaping global economies, societies, and individual lifestyles. Therefore, fierce competition among different companies is continuously undergoing, and special attention is focused on innovations to improve competitiveness. In the past several years, additive manufacturing (AM) has emerged as an innovative technology in applications in the automobile industry with significant advantages over traditional techniques. As a result, increasing efforts have been paid to combining AM technology with the development of the automobile industry. Currently, many automobile players are optimizing their industrial layout by incorporating innovative AM techniques, and meanwhile, a lot of research progress has been achieved in order to meet the market demand. This article aims at presenting a timely review to conclude the recent advances in the application of AM techniques in the automobile industry, focusing on the available AM techniques, printable materials, and industry applications, based on which the advantages and disadvantages of each technique and material system are discussed in order to reveal the current application situation. The current research gaps and challenges are also outlined to indicate future research opportunities. Hopefully, this work can be useful to related researchers as well as game players in the industry of this field.
Full article
(This article belongs to the Special Issue Additive Manufacturing of Materials: Process and Applications)
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Open AccessArticle
The Effects of Drying and Grinding on the Extraction Efficiency of Polyphenols from Grape Skin: Process Optimization
by
Lea Peternel, Tea Sokač Cvetnić, Jasenka Gajdoš Kljusurić, Tamara Jurina, Maja Benković, Ivana Radojčić Redovniković, Ana Jurinjak Tušek and Davor Valinger
Processes 2024, 12(6), 1100; https://doi.org/10.3390/pr12061100 - 27 May 2024
Abstract
Maximizing the yield of bioactive molecules extracted from plant materials requires the investigation of extraction process variables; therefore, in this research, a traditional aqueous solid–liquid extraction method was employed on two distinct grape pomace skin samples. The grape skin pomace represents a potentially
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Maximizing the yield of bioactive molecules extracted from plant materials requires the investigation of extraction process variables; therefore, in this research, a traditional aqueous solid–liquid extraction method was employed on two distinct grape pomace skin samples. The grape skin pomace represents a potentially valuable source of biologically active compounds, particularly polyphenols. Experiment 1 utilized ground grape pomace skin, whereas experiment 2 utilized grape pomace skin that had been both dried and ground beforehand. Employing a Box–Benkhen experimental design and response surface modeling in the Statistica 14.0 software package, this study evaluated the impact of temperature, extraction time, solid-to-liquid ratio (S/L), and mixing speed on extraction efficiency. The extracted compounds were assessed for both physical properties (conductivity, total dissolved solids, and pH) and chemical properties (total polyphenol content and antioxidant activity using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The optimization matrix design identified the specific conditions required to achieve the optimal physical and chemical properties of grape skin extract as follows: (i) for experiment 1, extraction time (t) = 15 min, temperature (T) = 80 °C, solid-to-liquid ratio (S/L) = 10 g/L, and mixing speed (rpm) = 500 1/min and (ii) for experiment 2, extraction time (t) = 15 min, temperature (T) = 80 °C, solid-to-liquid ratio (S/L) = 10 g/L, and mixing speed (rpm) = 375 1/min. Under optimal process conditions, 26.1284 mgGAE/gd.m. and 25.1024 mgGAE/gd.m., respectively, were obtained. These findings demonstrate the effectiveness of the optimization process in identifying precise extraction conditions that yield the optimal chemical properties of grape skin extracts.
Full article
(This article belongs to the Section Separation Processes)
Open AccessArticle
Numerical Simulation of Hydraulic Fracture Propagation on Multilayered Formation Using Limited Entry Fracturing Technique
by
Hexing Liu, Wenjuan Ji, Yi Huang, Wandong Zhang, Junlong Yang, Jing Xu and Mingyang Mei
Processes 2024, 12(6), 1099; https://doi.org/10.3390/pr12061099 - 27 May 2024
Abstract
Hydraulic fracturing is one of the most effective stimulation methods for unconsolidated sandstone reservoirs. However, the design of hydraulic fracturing must take into account the mechanical and stress properties of different geological formations between layers. In this paper, a three-dimensional coupled fluid-solid model
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Hydraulic fracturing is one of the most effective stimulation methods for unconsolidated sandstone reservoirs. However, the design of hydraulic fracturing must take into account the mechanical and stress properties of different geological formations between layers. In this paper, a three-dimensional coupled fluid-solid model using the finite element method is developed to investigate multiple vertical fractures at different depths along a vertical wellbore under different geological and geomechanical conditions. The finite element model does not require further refinement of any new cracks, requiring much smaller degrees of freedom and higher computational efficiency. In addition, new elements were used to account for local pressure drop due to perforation entry friction along the vertical wellbore. Numerical simulation results indicate that hydraulic fracture connections are observed from adjacent layers. Furthermore, the low stress contrast and high Young’s modulus between the layers increases the likelihood of multiple fracture connections. Higher fluid leakage rates increase the likelihood of fracture branching, but decrease the area of fracture coverage near the wellbore. Increasing fluid viscosity is effective in improving the area of fracture coverage near the wellbore. These findings are useful for the design of hydraulic fracturing in multi-layered formations in unconsolidated sandstone formations.
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(This article belongs to the Special Issue Study of Multiphase Flow and Its Application in Petroleum Engineering)
Open AccessArticle
Parabolic Modeling Forecasts of Space and Time European Hydropower Production
by
Cristina Lincaru, Adriana Grigorescu and Hasan Dincer
Processes 2024, 12(6), 1098; https://doi.org/10.3390/pr12061098 - 27 May 2024
Abstract
Renewable sources of energy production are some of the main targets today to protect the environment through reduced fossil fuel consumption and CO2 emissions. Alongside wind, solar, marine, biomass and nuclear sources, hydropower is among the oldest but still not fully explored
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Renewable sources of energy production are some of the main targets today to protect the environment through reduced fossil fuel consumption and CO2 emissions. Alongside wind, solar, marine, biomass and nuclear sources, hydropower is among the oldest but still not fully explored renewable energy sources. Compared with other sources like wind and solar, hydropower is more stable and consistent, offering increased predictability. Even so, it should be analyzed considering water flow, dams capacity, climate change, irrigation, navigation, and so on. The aim of this study is to propose a forecast model of hydropower production capacity and identify long-term trends. The curve fit forecast parabolic model was applied to 33 European countries for time series data from 1990 to 2021. Space-time cube ArcGIS representation in 2D and 3D offers visualization of the prediction and model confidence rate. The quadratic trajectory fit the raw data for 14 countries, validated by visual check, and in 20 countries, validated by FMRSE 10% threshold from the maximal value. The quadratic model choice is good for forecasting future values of hydropower electric capacity in 22 countries, with accuracy confirmed by the VMRSE 10% threshold from the maximal value. Seven local outliers were identified, with only one validated as a global outlier based on the Generalized Extreme Studentized Deviate (GESD) test at a 5% maximal number of outliers and a 90% confidence level. This result achieves our objective of estimating a level with a high degree of occurrence and offering a reliable forecast of hydropower production capacity. All European countries show a growing trend in the short term, but the trends show a stagnation or decrease if policies do not consider intensive growth through new technology integration and digital adoption. Unfortunately, Europe does not have extensive growth potential compared with Asia–Pacific. Public policies must boost hybrid hydro–wind or hydro–solar systems and intensive technical solutions.
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(This article belongs to the Special Issue Optimal Design for Renewable Power Systems)
Open AccessEditorial
Electrochemical Technology for New Materials Synthesis and Reprocessing
by
Yury P. Zaikov
Processes 2024, 12(6), 1097; https://doi.org/10.3390/pr12061097 - 27 May 2024
Abstract
It is difficult to underestimate the role of electrochemistry in the modern world. High-temperature technologies are essential for technological progress in the 21st century. [...]
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(This article belongs to the Special Issue Electrochemical Technology for New Materials Synthesis and Reprocessing)
Open AccessArticle
Strategies for Optimizing Shut-In Time: New Insights from Shale Long-Term Hydration Experiments
by
Bo Zeng, Enjia Dong, Zhiguang Yao, Yi Song, Zhuang Xiong, Yongzhi Huang, Xiaoyan Gou and Xiaodong Hu
Processes 2024, 12(6), 1096; https://doi.org/10.3390/pr12061096 - 27 May 2024
Abstract
In the process of hydraulic fracturing, fracturing fluid invades the formation and reacts with shale. Water-sensitive clay minerals swell when exposed to water. This results in a change in the mechanical properties of shale. However, the influences of a long-term water–shale reaction on
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In the process of hydraulic fracturing, fracturing fluid invades the formation and reacts with shale. Water-sensitive clay minerals swell when exposed to water. This results in a change in the mechanical properties of shale. However, the influences of a long-term water–shale reaction on mechanical properties are still unclear, and an optimization strategy of the shut-in time is required. In this paper, an optimization strategy for the shut-in time based on a shale long-term hydration experiment is proposed. In this paper, the water–shale reaction is simulated by laboratory experiments under normal temperature and pressure. The experiments are performed based on specimens from a shale outcrop. Clay and mineral composition, Young’s modulus, surface hardness, and tensile strength parameters are measured at 30-day intervals for 90 days. A CT scan was performed for 180 days. The experimental results show that the mass fraction of clay increased by 14.719%. In addition, significant argillaceous shedding occurs during the water–shale reaction period of 3–4 months. By testing the tensile strength, uniaxial compression decreases by 90.481% in three months. The Young’s modulus of mineral points decreases to 40% after reaction for three months. The shale has softened. The softening process is nonlinear and there are inflection points. The diffusion behavior of clay minerals and the expansion behavior of new fractures are observed by CT during 3–4 months of water–shale reaction. The results show that the shale softening and pore fracture structure changes are non-linear and heterogeneous, resulting in critical water–shale reaction time. According to the experimental results, the critical water–shale reaction time can be summarized. In this time, the fracture volume increases significantly, which is conducive to increasing oil and gas production. However, the fracture volume is not significantly increased by prolonging the shut-in time. The experimental results can guide the design of hydraulic fracturing shut-in time of shale reservoirs.
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(This article belongs to the Special Issue Innovations in Hydraulic Fracturing Technology for Unconventional Reservoirs)
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Open AccessArticle
ARM Cortex Simulation Design for Trajectory Curves Evaluation of Collaborative Robots’ Tungsten Inert Gas Welding
by
Shan Gao, Hua Geng, Yaqiong Ge and Wenbin Zhang
Processes 2024, 12(6), 1095; https://doi.org/10.3390/pr12061095 - 27 May 2024
Abstract
An ARM Cortex simulation system for collaborative welding robots is presented in this paper. The components of the ARM Cortex SoC for embedded robot control, an OpenGL ES with image rendering, and a 3D geometry engine OpenCasCade for modeling are integrated for the
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An ARM Cortex simulation system for collaborative welding robots is presented in this paper. The components of the ARM Cortex SoC for embedded robot control, an OpenGL ES with image rendering, and a 3D geometry engine OpenCasCade for modeling are integrated for the purposes of simulating system self-controllability and cost effectiveness. This simulation of a collaborative welding robot achieved convenience while meeting the performance requirements; meanwhile, the auxiliary design was able to mark the trajectory of the robot’s end effector and reveal the collaborative robot’s inverse kinematic parameters, namely the position and Euler angle. An ARM Linux X11 Window environment that was set to create a 3D simulation rendering algorithm was built simultaneously. Then, the STEP model of the robot was loaded by using the OpenCasCade functionality. After that, the robot model and complex spline surface could be visualized by using the Qt QGLWidget. Finally, the correctness of the kinematic algorithm was verified by conducting simulations and analyzing the robot’s kinematics through the simulation results, which could verify the expected design and provide a set of fundamental samples for the robot trajectory industry regarding welding applications.
Full article
(This article belongs to the Special Issue Process Automation and Smart Manufacturing in Industry 4.0/5.0)
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