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Volume 8
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Processes, Volume 8, Issue 1 (January 2020) – 125 articles

Cover Story (view full-size image): The demand on biologics has been constantly rising over the past decades and has become crucial in modern medicine. Due to progress that had been made in upstream processing (USP), difficulties arise in the downstream and demand for process intensification and innovative solutions. Process integration is one of the key strategies for intensifying and developing novel processes. Therefore, this work focuses on the integration of precipitation using a quality by design approach for process development. Further, the results obtained experimentally are taken to develop a predictive process model towards a digital twin and model-based advanced process control.View this paper.
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16 pages, 5810 KiB  
Article
Analysis of Dynamic Characteristics and Control Strategies of a Solvent Dehydration Distillation Column in a Purified Terephthalic Acid Plant
by Xiuhui Huang, Jun Wang and Zeqiu Li
Processes 2020, 8(1), 125; https://doi.org/10.3390/pr8010125 - 19 Jan 2020
Cited by 2 | Viewed by 5357
Abstract
In this study, a solvent dehydration column of purified terephthalic acid (PTA) plant was used as the research object. Based on a dynamic model of the solvent dehydration column, a dynamic sensitivity analysis of the key parameters was carried out using Aspen Dynamics. [...] Read more.
In this study, a solvent dehydration column of purified terephthalic acid (PTA) plant was used as the research object. Based on a dynamic model of the solvent dehydration column, a dynamic sensitivity analysis of the key parameters was carried out using Aspen Dynamics. After the dynamic model reached stability, the reflux rate, methyl acetate concentration, and reflux temperature of the solvent dehydration column were adjusted and the changes of the key separation indexes under the corresponding disturbance were analyzed. According to the analysis results, a sensitive plate temperature controller was added to carry out the dynamic sensitivity analysis. In addition, the acetic acid (HAc) concentration of the bottom of the column was found to be unstable in the dynamic sensitivity analysis. Considering the HAc concentration controller of the column bottom, two control strategies were designed. By analyzing the dynamic response of the feed flow disturbance under different control strategies, a more suitable control strategy under different conditions was obtained. From this, a reasonable method could be derived to design the control strategy, thereby providing a theoretical basis for further real-time optimization and advanced control of solvent dehydration in a PTA plant. Full article
(This article belongs to the Section Chemical Processes and Systems)
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Figure 1

Figure 1
<p>Acetate dehydration steady-state process flow.</p> Full article ">Figure 2
<p>Temperature and composition distribution during the steady-state of C-1 and C-3.</p> Full article ">Figure 2 Cont.
<p>Temperature and composition distribution during the steady-state of C-1 and C-3.</p> Full article ">Figure 3
<p>Three-phase balance model of the vapor–liquid–liquid rectification tray structure.</p> Full article ">Figure 4
<p>Sensitivity analysis of the R1 reflux in the C-1 column.</p> Full article ">Figure 5
<p>Dynamic sensitivity analysis of the R1 strand on the temperature of sensitive plate. (<b>a</b>) Dynamic sensitivity analysis of the R1 mass flow. (<b>b</b>) Sensitivity analysis of the MA mass fraction in R1. (<b>c</b>) Sensitivity analysis of the R1 temperature.</p> Full article ">Figure 6
<p>Sensitivity analysis of adding temperature controller. (<b>a</b>) Dynamic sensitivity analysis of the MA mass fraction in the R1 to the HAc mass fraction at the bottom of the column. (<b>b</b>) Dynamic sensitivity of temperature in the R1 to the HAc mass fraction at the bottom of the column.</p> Full article ">Figure 7
<p>Sensitivity analysis of the added temperature and component controllers. (<b>a</b>) Dynamic sensitivity analysis of the MA mass fraction in the R1 to the HAc mass fraction at the bottom of the column. (<b>b</b>) Dynamic sensitivity of the temperature in the R1 to the HAc mass fraction at the bottom of the column.</p> Full article ">Figure 8
<p>Sensitivity analysis of the HAc concentration in the bottom of the column after adding temperature and component controllers. (<b>a</b>) Sensitivity analysis of the HAc concentration at the bottom of the column. (<b>b</b>) Sensitivity analysis of the HAc mass flow at the bottom of the column.</p> Full article ">Figure 9
<p>Control strategies for the HAc dehydration system. (<b>a</b>) Control strategy 1 and (<b>b</b>) control strategy 2.</p> Full article ">Figure 10
<p>The control responses of CS1 and CS2 on the temperature of the 16th try. (<b>a</b>) Responses to disturbance in feed F1 and (<b>b</b>) responses to disturbance in feed F2.</p> Full article ">Figure 11
<p>The control responses of CS1 and CS2 to the mass fraction on the HAc at the bottom. (<b>a</b>) Responses to disturbance in feed F1 and (<b>b</b>) responses to disturbance in feed F2.</p> Full article ">Figure 12
<p>The control responses of the CS1 and CS2 strategies on the mass fraction of the HAc at the top. (<b>a</b>) Responses to disturbance in feed F1 and (<b>b</b>) responses to disturbance in feed F2.</p> Full article ">Figure 13
<p>The control response of CS1 CS2 to the heating of the column boiler reboiler. (<b>a</b>) Response to disturbance in feed F1 and (<b>b</b>) response to disturbance in feed F2.</p> Full article ">
23 pages, 4240 KiB  
Article
Screening of Amino Acids and Surfactant as Hydrate Promoter for CO2 Capture from Flue Gas
by Jyoti Shanker Pandey, Yousef Jouljamal Daas and Nicolas von Solms
Processes 2020, 8(1), 124; https://doi.org/10.3390/pr8010124 - 19 Jan 2020
Cited by 36 | Viewed by 4759
Abstract
In this study, the kinetics of flue gas hydrate formation in bulk water in the presence of selected amino acids and surfactants are investigated. Four amino acids (3000 ppm) are selected based on different hydropathy index. Constant-ramping and isothermal experiments at 120 bar [...] Read more.
In this study, the kinetics of flue gas hydrate formation in bulk water in the presence of selected amino acids and surfactants are investigated. Four amino acids (3000 ppm) are selected based on different hydropathy index. Constant-ramping and isothermal experiments at 120 bar pressure and 1 °C temperature are carried out to compare their hydrate promotion capabilities with surfactant sodium dodecyl sulfate (SDS) (500–3000 ppm) and water. Based on experimental results, we report the correlation between hydrate promotion capability of amino acids and their hydrophobicity. Hydrophobic amino acids show stronger flue gas hydrate promotion capability than water and hydrophilic amino acids. We discuss the controlling mechanisms to differentiate between promoters and inhibitors’ roles among the amino acids. Between 2000–3000 ppm concentrations, hydrophobic amino acids have near similar promotion capabilities as SDS. This research highlights the potential use of amino acids as promoters or inhibitors for various applications. Full article
(This article belongs to the Special Issue Analysis and Experimental Study on Natural Gas Hydrate Exploitation Processes)
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<p>Schematic diagram of the rocking cell-5 apparatus.</p> Full article ">Figure 2
<p>Flue gas (30 mole% CO<sub>2</sub>) hydrate formation in the presence of amino acids: P-T variation during constant ramping scheme for selected amino acid during flue gas hydrate formation with 30% CO<sub>2</sub>.</p> Full article ">Figure 3
<p>Flue gas (20 mole% CO2) hydrate formation in the presence of amino acids at 1 °C: P-T variation during isothermal experiments for selected amino acid during flue gas hydrate formation.</p> Full article ">Figure 4
<p>Subcooling kinetics in presence of amino acids and surfactant. Subcooling temperatures at the onset of the flue gas hydrate formation with amino acids and surfactant. (<b>a</b>) Subcooling temperature for 20% mole CO<sub>2</sub> for sodium dodecyl sulfate (SDS) at different concentration (fresh and memory). (<b>b</b>) Subcooling temperature for 20 and 30 mole% CO<sub>2</sub> for SDS at different concentration (fresh). (<b>c</b>) Subcooling temperature for 20% mole CO2 for amino acids at different concentration (fresh and memory). (<b>d</b>) Subcooling temperature for 20 and 30 mole% CO<sub>2</sub> for amino acids at different concentration (fresh).</p> Full article ">Figure 5
<p>Gas uptake (Fresh and Memory)-20% CO<sub>2</sub>: Gas uptake analysis for 20% CO<sub>2</sub> and effect of surfactant and different amino acids on the gas uptake for flue gas hydrate formation (20% CO<sub>2</sub>) measured during an isothermal experiment conducted at 120 bar and 1 °C recorded both for fresh and memory samples.</p> Full article ">Figure 6
<p>Gas uptake for fresh run (20% CO<sub>2</sub> and 30% CO<sub>2</sub>). Gas uptake during fresh runs for 20 and 30 mole% CO<sub>2</sub> with SDS and amino acid.</p> Full article ">Figure 7
<p>Pressure vs. time variation surfactant and amino acid at isothermal temp 1 °C. (<b>a</b>) Pressure vs. time curve surfactant (SDS 3000 ppm and SDS 1000 ppm) and amino acid (L-valine and L-methionine) for 20 mole% CO<sub>2</sub> at pressure 120 bar and 1 °C. (<b>b</b>) Pressure vs time curve surfactant (SDS 3000 ppm and SDS 1000 ppm) and amino acid (L-valine and L-methionine) for 30 mole% CO<sub>2</sub> at pressure 120 bar and 1 °C.</p> Full article ">Figure 8
<p>Effect on CO<sub>2</sub> recovery % due to the change in CO<sub>2</sub> concentration in the Flue gas. Change in CO<sub>2</sub> recovery % for surfactant and selected amino acids due to change in CO<sub>2</sub> mole % in the feed gas, measured during an isothermal experiment conducted at 120 bar, 1 °C.</p> Full article ">
15 pages, 2257 KiB  
Article
Multimode Operating Performance Visualization and Nonoptimal Cause Identification
by Yuhui Ying, Zhi Li, Minglei Yang and Wenli Du
Processes 2020, 8(1), 123; https://doi.org/10.3390/pr8010123 - 19 Jan 2020
Cited by 6 | Viewed by 2583
Abstract
In the traditional performance assessment method, different modes of data are classified mainly by expert knowledge. Thus, human interference is highly probable. The traditional method is also incapable of distinguishing transition data from steady-state data, which reduces the accuracy of the monitor model. [...] Read more.
In the traditional performance assessment method, different modes of data are classified mainly by expert knowledge. Thus, human interference is highly probable. The traditional method is also incapable of distinguishing transition data from steady-state data, which reduces the accuracy of the monitor model. To solve these problems, this paper proposes a method of multimode operating performance visualization and nonoptimal cause identification. First, multimode data identification is realized by subtractive clustering algorithm (SCA), which can reduce human influence and eliminate transition data. Then, the multi-space principal component analysis (MsPCA) is used to characterize the independent characteristics of different datasets, which enhances the robustness of the model with respect to the performance of independent variables. Furthermore, a self-organizing map (SOM) is used to train these characteristics and map them into a two-dimensional plane, by which the visualization of the process monitor is realized. For the online assessment, the operating performance of the current process is evaluated according to the projection position of the data on the visual model. Then, the cause of the nonoptimal performance is identified. Finally, the Tennessee Eastman (TE) process is used to verify the effectiveness of the proposed method. Full article
(This article belongs to the Special Issue Process Optimization and Control)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Schematic of process variations along different basis vectors.</p> Full article ">Figure 2
<p>Topology of self-organizing map network.</p> Full article ">Figure 3
<p>Training process of visual monitoring model for multi-modal operating conditions.</p> Full article ">Figure 4
<p>Economic benefit curve of each dataset.</p> Full article ">Figure 5
<p>Visual monitoring model based on subtractive clustering. (<b>a</b>) U-matrix map; (<b>b</b>) training map.</p> Full article ">Figure 6
<p>Visual monitoring model based on operator experience. (<b>a</b>) U-matrix map; (<b>b</b>) training map.</p> Full article ">Figure 7
<p>Test data mapping results. (<b>a</b>) test (general); (<b>b</b>) test (best).</p> Full article ">Figure 8
<p>Online process operation performance monitoring results. (<b>a</b>) general; (<b>b</b>) general–poor; (<b>c</b>) general–poor–good; (<b>d</b>) general–poor–good–best.</p> Full article ">Figure 9
<p>Online process performance assessment results.</p> Full article ">Figure 10
<p>Nonoptimal performance cause identification result. (<b>a</b>) “General” grade nonoptimal cause identification; (<b>b</b>) “poor” grade nonoptimal cause identification; (<b>c</b>) “good” grade nonoptimal cause identification.</p> Full article ">
21 pages, 11290 KiB  
Article
Numerical Study on the Influence of Inlet Guide Vanes on the Internal Flow Characteristics of Centrifugal Pump
by Peifeng Lin, Yongzheng Li, Wenbin Xu, Hui Chen and Zuchao Zhu
Processes 2020, 8(1), 122; https://doi.org/10.3390/pr8010122 - 17 Jan 2020
Cited by 14 | Viewed by 4012
Abstract
In order to make the centrifugal pump run efficiently and stably under various working conditions, the influences of the incoming vortex flow in the inlet pipe on the main flow in the impeller is studied numerically, based on the k − ω SST [...] Read more.
In order to make the centrifugal pump run efficiently and stably under various working conditions, the influences of the incoming vortex flow in the inlet pipe on the main flow in the impeller is studied numerically, based on the k − ω SST turbulence model. Some guide vanes with different offset angle were added to change the statistical characteristic of the internal flow in the inlet pipe of the centrifugal pump. Both contour distributions of internal flow and statistical results of external performance are obtained and analyzed. The results show that the existence of vanes can divide the large vortex because of the reversed flow from the rotating impeller at low flow rate conditions into small vortices, which are easier to dissipate, make the velocity and pressure distribution more uniform, improve the stability of the flow in the impeller, reduce the hydraulic loss, and improve the hydraulic performance of the pump. The pump with vanes of offset angle 25° has a small pressure pulsation amplitude at each monitoring point. Comparing with the performance of the original pump, the head increased by around 2% and efficiency increased by around 2.5% of the pump with vanes of offset angle 25°. Full article
(This article belongs to the Collection Modeling, Simulation and Computation on Dynamics of Complex Fluids)
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Figure 1
<p>Three-dimensional model and mesh model of the centrifugal pump.</p> Full article ">Figure 2
<p>Schematic diagram of inlet guide vanes.</p> Full article ">Figure 3
<p>Grid diagram and the centrifugal pump with vanes.</p> Full article ">Figure 4
<p>The scheme of the test rig.</p> Full article ">Figure 5
<p>Comparison of experimental and simulation results for pump head and efficiency.</p> Full article ">Figure 6
<p>Numerical distribution of Q criteria for inlet and outlet sections with or without inlet guide vanes.</p> Full article ">Figure 7
<p>Volute cross section and monitoring point distribution.</p> Full article ">Figure 8
<p>Sectional velocity contour in the impeller.</p> Full article ">Figure 8 Cont.
<p>Sectional velocity contour in the impeller.</p> Full article ">Figure 9
<p>Turbulent kinetic energy distribution in the impeller.</p> Full article ">Figure 9 Cont.
<p>Turbulent kinetic energy distribution in the impeller.</p> Full article ">Figure 10
<p>Velocity distribution in the volute cross-section.</p> Full article ">Figure 10 Cont.
<p>Velocity distribution in the volute cross-section.</p> Full article ">Figure 11
<p>Pressure analysis of interface between volute and impeller.</p> Full article ">Figure 11 Cont.
<p>Pressure analysis of interface between volute and impeller.</p> Full article ">Figure 12
<p>Static pressure distribution of section VI for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 12 Cont.
<p>Static pressure distribution of section VI for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 13
<p>Static pressure distribution of section VIII for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 14
<p>Monitoring point pressure pulsation near the tongue for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 14 Cont.
<p>Monitoring point pressure pulsation near the tongue for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 15
<p>Frequency domain diagram of pressure pulsation in Section VI for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 15 Cont.
<p>Frequency domain diagram of pressure pulsation in Section VI for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 16
<p>Frequency domain diagram of pressure pulsation in section VIII for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 16 Cont.
<p>Frequency domain diagram of pressure pulsation in section VIII for different flow rates: (<b>a</b>) 0.4<span class="html-italic">Q</span><sub>d</sub>, (<b>b</b>) 0.6<span class="html-italic">Q</span><sub>d</sub>, (<b>c</b>) 0.8<span class="html-italic">Q</span><sub>d.</sub></p> Full article ">Figure 17
<p>External characteristic curve of centrifugal pump.</p> Full article ">
29 pages, 1072 KiB  
Review
Modeling and Exploiting Microbial Temperature Response
by Philipp Noll, Lars Lilge, Rudolf Hausmann and Marius Henkel
Processes 2020, 8(1), 121; https://doi.org/10.3390/pr8010121 - 17 Jan 2020
Cited by 26 | Viewed by 10187
Abstract
Temperature is an important parameter in bioprocesses, influencing the structure and functionality of almost every biomolecule, as well as affecting metabolic reaction rates. In industrial biotechnology, the temperature is usually tightly controlled at an optimum value. Smart variation of the temperature to optimize [...] Read more.
Temperature is an important parameter in bioprocesses, influencing the structure and functionality of almost every biomolecule, as well as affecting metabolic reaction rates. In industrial biotechnology, the temperature is usually tightly controlled at an optimum value. Smart variation of the temperature to optimize the performance of a bioprocess brings about multiple complex and interconnected metabolic changes and is so far only rarely applied. Mathematical descriptions and models facilitate a reduction in complexity, as well as an understanding, of these interconnections. Starting in the 19th century with the “primal” temperature model of Svante Arrhenius, a variety of models have evolved over time to describe growth and enzymatic reaction rates as functions of temperature. Data-driven empirical approaches, as well as complex mechanistic models based on thermodynamic knowledge of biomolecular behavior at different temperatures, have been developed. Even though underlying biological mechanisms and mathematical models have been well-described, temperature as a control variable is only scarcely applied in bioprocess engineering, and as a conclusion, an exploitation strategy merging both in context has not yet been established. In this review, the most important models for physiological, biochemical, and physical properties governed by temperature are presented and discussed, along with application perspectives. As such, this review provides a toolset for future exploitation perspectives of temperature in bioprocess engineering. Full article
(This article belongs to the Special Issue Bioprocess Monitoring and Control)
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Figure 1

Figure 1
<p>Timeline of temperature models described in paragraphs 2–3 starting in 1889 with the semi-empirical Arrhenius model. First author of the described model (paragraph number; equation number). Models marked with bold letters are described in detail and the remaining models in non-bold letters are summarized in <a href="#processes-08-00121-t001" class="html-table">Table 1</a>.</p> Full article ">Figure 2
<p>Scheme of the thermal growth curve where the temperature (K) is plotted against the growth rate (s<sup>−1</sup>). Cardinal temperatures (<span class="html-italic">T<sub>min</sub></span>, <span class="html-italic">T<sub>opt</sub></span>, and <span class="html-italic">T<sub>max</sub></span>) with their corresponding growth rates (<span class="html-italic">µ<sub>opt</sub></span> and <span class="html-italic">µ<sub>50%opt</sub></span>) are indicated.</p> Full article ">
11 pages, 3170 KiB  
Article
Characteristics of Low-Temperature Polyvinyl Chloride Carbonization by Catalytic CuAl Layered Double Hydroxide
by Erwei Pang, Weijun Liu, Shuhua Zhang, Nengshuo Fu and Zhongxun Tian
Processes 2020, 8(1), 120; https://doi.org/10.3390/pr8010120 - 17 Jan 2020
Cited by 5 | Viewed by 4667
Abstract
A good way to make carbon materials was presented in low-temperature polyvinyl chloride (PVC) carbonization by catalysis. The process of low-temperature PVC carbonization by CuAl-layered double hydroxide (CuAl-LDH) was investigated by thermogravimetric analysis (TGA) and tubular furnace. The results show that CuAl-LDH accounting [...] Read more.
A good way to make carbon materials was presented in low-temperature polyvinyl chloride (PVC) carbonization by catalysis. The process of low-temperature PVC carbonization by CuAl-layered double hydroxide (CuAl-LDH) was investigated by thermogravimetric analysis (TGA) and tubular furnace. The results show that CuAl-LDH accounting for 5% of PVC mass enabled acceleration of the dehydrochlorination in PVC as soon as possible and maximized the yield of the PVC carbonized product. The vacuum with 0.08 MPa, 20 °C/min heating rate and 90 min carbonized maintenance time were optimal for PVC carbonization. Moreover, the best morphology and yield of the carbonized product was provided at a carbonization temperature of 300 °C. Full article
(This article belongs to the Special Issue Processes for Bioenergy and Resources Recovery from Biowaste)
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<p>Diagram of apparatus of pyrolysis.</p> Full article ">Figure 2
<p>DTG and TG curves for the degradation of PVC and its composite: (<b>a</b>) the curve of DerivativeThermogravimetry; (<b>b</b>) the curve of Thermogravimetry.</p> Full article ">Figure 3
<p>TG curves for the pyrolysis of pure PVC and its composites.</p> Full article ">Figure 4
<p>The morphology of the carbonized product under different pyrolysis atmospheres: (<b>a</b>) nitrogen; (<b>b</b>) vacuum; (<b>c</b>) air.</p> Full article ">Figure 5
<p>The yield of carbonized product under three different pyrolysis atmospheres.</p> Full article ">Figure 6
<p>The morphology of the carbonized product.</p> Full article ">Figure 7
<p>The curves for the yield of carbonized product different carbonization temperatures.</p> Full article ">Figure 8
<p>TG curves for the pyrolysis of PVC/CuAl-LDH-5% at different heating rates.</p> Full article ">Figure 9
<p>The curve for the yield of carbonized product with different carbonization maintenance times.</p> Full article ">Figure 10
<p>Images of the acid-washed carbonized product of PVC/CuAl-LDH-5%: (<b>a</b>) the surface of carbonized product; (<b>b</b>) the amplifying surface of carbonized product.</p> Full article ">
12 pages, 1358 KiB  
Article
Energy and Material Flows and Carbon Footprint Assessment Concerning the Production of HMF and Furfural from a Cellulosic Biomass
by Hannes Schöppe, Peter Kleine-Möllhoff and Rolf Epple
Processes 2020, 8(1), 119; https://doi.org/10.3390/pr8010119 - 17 Jan 2020
Cited by 22 | Viewed by 5607
Abstract
5-hydroxymethyl-furfural (HMF) and furfural are interesting as potential platform chemicals for a bio-based chemical production economy. Within the scope of this work, the process routes under technical development for the production of these platform chemicals were investigated. For two selected processes, the material [...] Read more.
5-hydroxymethyl-furfural (HMF) and furfural are interesting as potential platform chemicals for a bio-based chemical production economy. Within the scope of this work, the process routes under technical development for the production of these platform chemicals were investigated. For two selected processes, the material and energy flows, as well as the carbon footprint, were examined in detail. The possible production process optimizations, further development potentials, and the research demand against the background of the reduction of the primary energy expenditure were worked out. Full article
(This article belongs to the Special Issue Biomass Processing and Conversion Systems)
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<p>Production process of HMF (following the pilot process of the literature [<a href="#B15-processes-08-00119" class="html-bibr">15</a>]).</p> Full article ">Figure 2
<p>Material and energy flows as well as CO<sub>2</sub> emissions during HMF synthesis (according to the pilot process of the authors of [<a href="#B15-processes-08-00119" class="html-bibr">15</a>]).</p> Full article ">Figure 3
<p>Energy consumption in the synthesis of HMF (according to the pilot process of the literature [<a href="#B15-processes-08-00119" class="html-bibr">15</a>]).</p> Full article ">Figure 4
<p>Production process for the continuous production of furfural using the Huaxia Furfural technology. Modified by Westpro (according to the authors of [<a href="#B18-processes-08-00119" class="html-bibr">18</a>]).</p> Full article ">Figure 5
<p>Material and energy flows, as well as CO<sub>2</sub> emissions from the synthesis of furfural (using the Huaxia Furfural technology, modified by Westpro).</p> Full article ">Figure 6
<p>Energy intensity in the synthesis of furfural (when using the Huaxia Furfural technology modified by Westpro).</p> Full article ">
11 pages, 1142 KiB  
Article
Polyetherimide-Montmorillonite Nano-Hybrid Composite Membranes: CO2 Permeance Study via Theoretical Models
by Asif Jamil, Oh Pei Ching, Muhammad Naqvi, Hafiza Aroosa Aslam Khan and Salman Raza Naqvi
Processes 2020, 8(1), 118; https://doi.org/10.3390/pr8010118 - 17 Jan 2020
Cited by 2 | Viewed by 2705
Abstract
The incorporation of aminolauric acid modified montmorillonite (f-MMT) in polyetherimide (PEI) has been implemented to develop hollow fibre nano-hybrid composite membranes (NHCMs) with improved gas separation characteristics. The aforementioned characteristics are caused by enhanced f-MMT spatial dispersion and interfacial interactions [...] Read more.
The incorporation of aminolauric acid modified montmorillonite (f-MMT) in polyetherimide (PEI) has been implemented to develop hollow fibre nano-hybrid composite membranes (NHCMs) with improved gas separation characteristics. The aforementioned characteristics are caused by enhanced f-MMT spatial dispersion and interfacial interactions with PEI matrix. In this study, existing gas permeation models such as, Nielsen, Cussler, Yang–Cussler, Lape–Cussler and Bharadwaj were adopted to estimate the dispersion state of f-MMT and to predict the CO2 permeance in developed NHCMs. It was found out that the average aspect ratio estimated was 53, with 3 numbers of stacks per unit tactoid, which showed that the intercalation f-MMT morphology is the dominating dispersion state of filler in PEI matrix. Moreover, it was observed that Bharadwaj model showed the least average absolute relative error (%AARE) values till 3 wt. % f-MMT loading in the range of ±10 for a pressure range of 2 to 10 bar. Hence, Bharadwaj was the best fit model for the experimental data compared to other models, as it considers the platelets orientation. Full article
(This article belongs to the Special Issue Nano-Hybrid Composite Membranes)
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Figure 1
<p>Estimation of <span class="html-italic">f</span>-MMT aspect ratio by using (<b>a</b>) Nielsen, (<b>b</b>) Cussler, (<b>c</b>) Yang–Cussler, (<b>d</b>) Lape–Cussler, and (<b>e</b>) Bharadwaj, permeation models.</p> Full article ">Figure 2
<p>Schematics of calculating stacks per unit tactoid via Bharadwaj method.</p> Full article ">Figure 3
<p>Bharadwaj model for polyetherimide–modified montmorillonite (PEI-<span class="html-italic">f</span>-MMT) NHCMs.</p> Full article ">
12 pages, 1847 KiB  
Article
Correlation between Antibacterial Activity and Free-Radical Scavenging: In-Vitro Evaluation of Polar/Non-Polar Extracts from 25 Plants
by Mahmoud Rayan, Baheer Abu-Farich, Walid Basha, Anwar Rayan and Saleh Abu-Lafi
Processes 2020, 8(1), 117; https://doi.org/10.3390/pr8010117 - 17 Jan 2020
Cited by 16 | Viewed by 4818
Abstract
Objectives: The current study aimed to measure the antioxidant and antibacterial activities of 25 wild Palestinian edible plants, which were subjected to extraction by polar and non-polar solvents. Correlations between free radical scavenging activity and antibacterial activity of the extracts were assessed for [...] Read more.
Objectives: The current study aimed to measure the antioxidant and antibacterial activities of 25 wild Palestinian edible plants, which were subjected to extraction by polar and non-polar solvents. Correlations between free radical scavenging activity and antibacterial activity of the extracts were assessed for both polar and non-polar fractions. Materials: Twenty-five wild edible plant species that are frequently consumed by people in Palestine (mainly in a rural area) were examined. Among them, 10 plant species were among those with the highest mean cultural importance values, according to an ethnobotanical survey that was conducted in the West Bank, Palestine, a few years ago. Method: The protocol of the DPPH assay for testing free-radical scavenging was utilized for determining EC50 values, while microdilution tests were conducted to determine the 50% inhibitory concentration (IC50) of the extracts for the microorganism Staphylococcus mutans. Results and Discussion: Eight extracts (non-polar fractions) were found to possess an antibacterial IC50 of less than 20 ppm, such as Foeniculum vulgare, Salvia palaestinafruticose, Micromeria fruticose, Trigonella foenum-graecum, Cichorium pumilum jacq, Salvia hierosolymitana boiss, Ruta chalepensis, and Chrysanthemum coronarium. The polar fractions possess higher antioxidant activity, while non-polar fraction possess higher antibacterial activity. Looking at all the results together can deceive and lead to the conclusion that there is no correlation between antibacterial activity against S. mutans and free radical scavenging (R2 equals 0.0538). However, in-depth analysis revealed that non-polar plant extracts with an EC50 of free radical scavenging ≤100 ppm have a four-fold order of enrichment toward more activity against S. mutans. These findings are of high importance for screening projects. A four-fold order of enrichment could save plenty of time and many in screening projects. The antibacterial active extracts marked by low-medium free radical scavenging might act through a mechanism of action other than that of highly active, free radical scavenging extracts. Conclusion: The screening of antioxidant and antimicrobial activity performed on 25 selected wild plant extracts revealed a satisfactory free radical scavenging and antimicrobial potential that could be of value in the management of oxidative stress. Further studies are recommended to explore novel and highly active natural antibacterial products. Full article
(This article belongs to the Special Issue Extraction, Characterization and Pharmacology of Natural Products)
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<p>Correlations between the EC<sub>50</sub> for free radical scavenging and antibacterial activity (IC<sub>50</sub>) for the non-polar extracts.</p> Full article ">Figure 2
<p>Correlations between antibacterial activity (IC<sub>50</sub>) and the EC<sub>50</sub> for free radical scavenging for the eight most active plant extracts against <span class="html-italic">S. mutans</span>.</p> Full article ">Figure 3
<p>Enrichment plot of the prediction model for the antibacterial activity of the plant extracts, based on their free radical scavenging activity (non-polar extracts).</p> Full article ">Figure 4
<p>A receiver operating characteristic (ROC) curve showing the performance of the antibacterial/free radical scavenging correlation model.</p> Full article ">
12 pages, 5879 KiB  
Article
Controllability Comparison of the Four-Product Petlyuk Dividing Wall Distillation Column Using Temperature Control Schemes
by Xing Qian, Rui Liu, Kejin Huang, Haisheng Chen, Yang Yuan, Liang Zhang and Shaofeng Wang
Processes 2020, 8(1), 116; https://doi.org/10.3390/pr8010116 - 16 Jan 2020
Cited by 6 | Viewed by 3297
Abstract
An effective process intensification strategy based on dividing walls shows promising energy-saving results for distillation processes. The three-product Petlyuk dividing wall distillation columns (DWDCs) are able to save approximately 30% energy in comparison with the traditional distillation columns. Furthermore, the four-product extended Petlyuk [...] Read more.
An effective process intensification strategy based on dividing walls shows promising energy-saving results for distillation processes. The three-product Petlyuk dividing wall distillation columns (DWDCs) are able to save approximately 30% energy in comparison with the traditional distillation columns. Furthermore, the four-product extended Petlyuk DWDC reduces about 50% of operation costs than conventional distillation sequences. Although researchers have extensively studied control schemes for the three-product Petlyuk DWDC, relatively little work has been done on the four-product extended Petlyuk DWDC. This paper studies feasible temperature control schemes containing temperature control scheme (TC), simplified temperature difference control scheme (STDC), and simplified double temperature difference control scheme (SDTDC) for the four-product extended Petlyuk DWDC. STDC and SDTDC are introduced so as to improve the dynamic performances with simple control schemes. All three control schemes are tested against a series of feed compositions and feed rate disturbances. Dynamic performances prove that the proposed STDC and SDTDC schemes are better at handling the inserted feed disturbances. These are very encouraging results for industrialization of the four-product extended Petlyuk DWDC in the future. Full article
(This article belongs to the Special Issue Process Optimization and Control)
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<p>The extended Petlyuk dividing wall distillation column (DWDC).</p> Full article ">Figure 2
<p>Thermally coupled structure of the extended Petlyuk DWDC.</p> Full article ">Figure 3
<p>The detailed data of the four-product extended Petlyuk DWDC.</p> Full article ">Figure 4
<p>Sensitivity analysis profiles: (<b>a</b>) D; (<b>b</b>) S1; (<b>c</b>) S2; (<b>d</b>) L1; (<b>e</b>) L2; (<b>f</b>) L3.</p> Full article ">Figure 5
<p>Singular value decomposition analysis profiles for the simplified temperature difference control scheme (STDC): (<b>a</b>) L1; (<b>b</b>) L2; (<b>c</b>) L3.</p> Full article ">Figure 6
<p>Singular value decomposition analysis profiles for simplified double temperature difference control scheme (SDTDC): (<b>a</b>) L1; (<b>b</b>) L2; (<b>c</b>) L3.</p> Full article ">Figure 7
<p>Temperature control (TC) scheme.</p> Full article ">Figure 8
<p>Simplified temperature difference control scheme (STDC).</p> Full article ">Figure 9
<p>Simplified double temperature difference control scheme (SDTDC).</p> Full article ">Figure 10
<p>Dynamic responses in face of ±10% feed composition disturbances.</p> Full article ">Figure 10 Cont.
<p>Dynamic responses in face of ±10% feed composition disturbances.</p> Full article ">Figure 11
<p>Dynamic responses in face of ±10% feed flow disturbances.</p> Full article ">
20 pages, 3249 KiB  
Review
Plasmonic-Active Nanostructured Thin Films
by Jay K. Bhattarai, Md Helal Uddin Maruf and Keith J. Stine
Processes 2020, 8(1), 115; https://doi.org/10.3390/pr8010115 - 16 Jan 2020
Cited by 17 | Viewed by 9960
Abstract
Plasmonic-active nanomaterials are of high interest to scientists because of their expanding applications in the field for medicine and energy. Chemical and biological sensors based on plasmonic nanomaterials are well-established and commercially available, but the role of plasmonic nanomaterials on photothermal therapeutics, solar [...] Read more.
Plasmonic-active nanomaterials are of high interest to scientists because of their expanding applications in the field for medicine and energy. Chemical and biological sensors based on plasmonic nanomaterials are well-established and commercially available, but the role of plasmonic nanomaterials on photothermal therapeutics, solar cells, super-resolution imaging, organic synthesis, etc. is still emerging. The effectiveness of the plasmonic materials on these technologies depends on their stability and sensitivity. Preparing plasmonics-active nanostructured thin films (PANTFs) on a solid substrate improves their physical stability. More importantly, the surface plasmons of thin film and that of nanostructures can couple in PANTFs enhancing the sensitivity. A PANTF can be used as a transducer for any of the three plasmonic-based sensing techniques, namely, the propagating surface plasmon, localized surface plasmon resonance, and surface-enhanced Raman spectroscopy-based sensing techniques. Additionally, continuous nanostructured metal films have an advantage for implementing electrical controls such as simultaneous sensing using both plasmonic and electrochemical techniques. Although research and development on PANTFs have been rapidly advancing, very few reviews on synthetic methods have been published. In this review, we provide some fundamental and practical aspects of plasmonics along with the recent advances in PANTFs synthesis, focusing on the advantages and shortcomings of the fabrication techniques. We also provide an overview of different types of PANTFs and their sensitivity for biosensing. Full article
(This article belongs to the Special Issue Materials Processing for Production of Nanostructured Thin Films)
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<p>Schematic diagrams illustrating the excitation of surface plasmons from (<b>a</b>) thin film using prism as a coupling device, generating propagating surface plasmon or surface plasmon polariton (SPP), and (<b>b</b>) nanoparticle, generating a localized surface plasmon resonance (LSPR). The typical spectra that can be obtained after the surface plasmon excitation are shown on the right.</p> Full article ">Figure 2
<p>Schematic of commonly applied strategies for the synthesis of plasmonic-active nanostructured thin films starting from (<b>a</b>) deposition on patterned template, (<b>b</b>) deposition on patterned substrate, (<b>c</b>) deposition on planar substrate, and (<b>d</b>) transfer on planar substrate.</p> Full article ">Figure 3
<p>(<b>a</b>) Schematic representation of process steps for fabricating nanohole arrays using nanosphere lithography. (<b>b</b>) SEM images of (top) the resulting large area (~30 × 30 µm<sup>2</sup>) single crystalline hexagonal nanohole array, (middle) an elliptical nanohole array (60° tilt angle) after nanosphere removal, and (bottom) after 4 min Ag electroless plating onto the nanohole array. (<b>c</b>) SERS spectra of (<b>A</b>) 4 min Ag plated nanohole array, (<b>B</b>) 4 min Ag plated flat silver film, (<b>C</b>) a standard nanohole array, and (<b>D</b>) 5× a flat silver film. All substrates were exposed to 1 mM benzenethiol prior to SERS measurements. P = 0.32 mW, t = 180 s, and λ<sub>max</sub> = 532 nm. Reproduced (<b>a</b>,<b>c</b>) and adapted (<b>b</b>) with permission from Reference [<a href="#B56-processes-08-00115" class="html-bibr">56</a>], Copyright 2009, American Chemical Society.</p> Full article ">Figure 4
<p>(<b>A</b>) Schematic for fabricating the large-area nanohole arrays. (<b>a</b>) A thermal resist layer spun on a Si wafer is imprinted with a nanoimprint stamp with circular post patterns. (<b>b</b>) The Si wafer is subsequently etched to be a nanohole template with deep circular trenches. (<b>c</b>) A metal film is directionally deposited on the Si template. (<b>d</b>) The metal surface is coated with a thin layer of epoxy and covered with a glass slide. The Ag film is then peeled off of the template to reveal the smooth nanohole array made in the metal film. The Si template can be reused to make multiple identical samples. (<b>B</b>) (<b>a</b>) A SEM image of the Si template with deep circular trenches. (<b>b</b>) A cross-sectional SEM image of the Si template after depositing a 100 nm thick Ag film. (<b>c</b>) A SEM image of the template-stripped Ag periodic nanohole array. The inset shows a zoomed-in image of the template-stripped Ag nanoholes. The diameter of the nanoholes and periodicity of the array are 180 and 500 nm, respectively. (<b>d</b>) A photograph of the fabricated nanohole array chip. A 26.5 mm × 26.5 mm area of 100 nm-thick Ag film with nanohole patterns in an 8 mm × 8 mm area in the center is transferred to a standard microscope slide. The inset in panel d shows a photograph of a multi-channel PDMS chip attached on the silica-coated nanohole array chip. Reproduced with permission from Reference [<a href="#B44-processes-08-00115" class="html-bibr">44</a>], Copyright 2011, American Chemical Society.</p> Full article ">Figure 5
<p>SEM images of AgFON-505 (<b>a</b>), AuNP-AgFON-505 (<b>b</b>), with cross-sectional image of AuNP-AgFON-505 (<b>c</b>). Raman spectra of AuNP-AgFON-505, AgFON-505, and AuNP-Ag film substrates (<b>d</b>). Raman mapping images of AuNP-AgFON-505 versus AgFON-505 at 785 nm excitation laser (<b>e</b>,<b>f</b>). (<b>g</b>) FDTD simulations of E-fields on AuNP assemblies on AgFON-505 substrate at 785 nm laser wavelength. Partially enlarged image for dimer AuNPs (<b>g1</b>) and crevice gap (<b>g2</b>) in AuNP-AgFON-505 system. Reproduced with permission from Reference [<a href="#B78-processes-08-00115" class="html-bibr">78</a>], Copyright 2016, American Chemical Society.</p> Full article ">Figure 6
<p>(<b>a</b>) Schematic illustration of preparation of the film over nanowell surfaces. (<b>b</b>) SEM images of Ag film over nanowell surface [diameter of nanospheres (D) = 510 nm; mass thickness of Ag film (<span class="html-italic">d</span><sub>m</sub>) = 50 nm; and etch time (<span class="html-italic">t</span><sub>e</sub>) = 10 min]. (<b>A</b>) Well-packed area of over 40 µm<sup>2</sup> and (<b>B</b>) magnified image of the same sample. The SEM accelerating voltage was 5 kV. (<b>c</b>) (<b>A</b>) Collection of reflectance spectra of Ag film over nanowell surface in different solvents (D = 590 nm; <span class="html-italic">d</span><sub>m</sub> = 50 nm). (<b>B</b>) Plots of λ<sub>min</sub> (solvent)–λ<sub>min</sub> (dry nitrogen) versus refractive index of the solvent for three nanosphere sizes: D = 450, 510, and 590 nm. Each data point represents the average value obtained from at least three surfaces. Error bars show the standard deviations. For all surface preparations, <span class="html-italic">d</span><sub>m</sub> = 50 nm and <span class="html-italic">t</span><sub>e</sub> = 10 min. Reproduced with permission from Reference [<a href="#B41-processes-08-00115" class="html-bibr">41</a>], Copyright 2005, American Chemical Society.</p> Full article ">Figure 7
<p>(<b>a</b>) Native surface data for the nanospike deposition from precursor solution of 6.8 mM HAuCl<sub>4</sub> and 1 mM Pb(CH<sub>3</sub>COO)<sub>2</sub>: column (1) SEM (45° tilted) and column (2) AFM images of the gold nanospike surfaces as a function of electrodeposition time. The red and white scale bars are 200 nm and 1 mm, respectively. 2D-FFT data (insets) are shown for the top-down SEM images. Adapted with permission from Reference [<a href="#B80-processes-08-00115" class="html-bibr">80</a>], Copyright 2018, The Royal Society of Chemistry. (<b>b</b>) (<b>A</b>) SEM images of nanostructured gold film (NGF) prepared by providing −1.2 V for 60 s followed by −1.6 V for 30 s (vs. Ag/AgCl (KCl, Satd) from 50 mM potassium dicyanoaurate. Scale bars: 2 µm. Insets are the corresponding higher magnification SEM images (scale bars: 0.2 µm). (<b>B</b>) Optical set up for localized surface plasmon resonance spectroscopy in reflection mode. (<b>C</b>) Bulk refractive index response of as-prepared NGF evident by change in LSPR peak wavelength. (<b>D</b>) Real-time LSPR response of self-assembled monolayer (SAM)-modified NGF to different concentrations of Concanavalin A. NGF was surface modified with a mixed SAM of αMan-C8-SH and TEG-SH (1:3). Reproduced with permission from Reference [<a href="#B50-processes-08-00115" class="html-bibr">50</a>], Copyright 2014, Elsevier Ltd.</p> Full article ">
18 pages, 1395 KiB  
Article
Research on Green Power Dispatching Based on an Emergy-Based Life Cycle Assessment
by Tao Li, Yi Miao Song, Ang Li, Jing Shen, Chao Liang and Ming Gao
Processes 2020, 8(1), 114; https://doi.org/10.3390/pr8010114 - 16 Jan 2020
Cited by 8 | Viewed by 2930
Abstract
Environmental protection pressures and green energy strategies have created major challenges for a cleaner production of China’s coal-fired power generation. Although China’s electric power dispatching department has tried to prioritize clean energy, the current dispatching models lack environmental indicators related to coal-fired power [...] Read more.
Environmental protection pressures and green energy strategies have created major challenges for a cleaner production of China’s coal-fired power generation. Although China’s electric power dispatching department has tried to prioritize clean energy, the current dispatching models lack environmental indicators related to coal-fired power generation. The main purpose of this paper is to provide a comprehensive environmental indicator for the cleanliness evaluation of coal-fired power plants. In this paper, the (Emergy-based Life Cycle Assessment) Em-LCA method is used to measure and analyze environmental related resource consumption, socio-economic investment, and emissions in the whole life cycle of coal-fired power plants. At the same time, based on the above three environmental impacts in the whole life cycle, this paper constructs the (Em-LCA based Cleaner Production Comprehensive Evaluation) ECPCE index to guide a green dispatching plan. By comparing the calculation results of the index, this paper finds that there are differences in the environmental advantages of different generating units in green dispatching, which are closely related to the process management of coal-fired power plants in production and the environment. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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<p>The emergy-base life cycle assessment (Em-LCA) methodology for coal-fired power generation.</p> Full article ">Figure 2
<p>Comparisons of renewable and non-renewable resource consumption (×10<sup>24</sup>).</p> Full article ">Figure 3
<p>Life Cycle renewable and non-renewable resource consumption (×10<sup>11</sup>).</p> Full article ">Figure 4
<p>Life Cycle socio-economic investment.</p> Full article ">Figure 5
<p>Socio-economic investment of waste treatment stage.</p> Full article ">Figure 6
<p>Life cycle emission emergy of whole coal-fired power plant.</p> Full article ">Figure 7
<p>The ECPCE index of four generating units.</p> Full article ">
13 pages, 3288 KiB  
Article
The Potential Antibacterial and Antifungal Activities of Wood Treated with Withania somnifera Fruit Extract, and the Phenolic, Caffeine, and Flavonoid Composition of the Extract According to HPLC
by Mervat EL-Hefny, Mohamed Z. M. Salem, Said I. Behiry and Hayssam M. Ali
Processes 2020, 8(1), 113; https://doi.org/10.3390/pr8010113 - 16 Jan 2020
Cited by 40 | Viewed by 6415
Abstract
In the present study, Melia azedarach wood blocks treated with different acetone extract concentrations from Withania somnifera fruits are assessed for their antibacterial and anti-fungal activities. Wood blocks of M. azedarach treated with W. somnifera fruit extract at concentrations of 0, 1, 2, [...] Read more.
In the present study, Melia azedarach wood blocks treated with different acetone extract concentrations from Withania somnifera fruits are assessed for their antibacterial and anti-fungal activities. Wood blocks of M. azedarach treated with W. somnifera fruit extract at concentrations of 0, 1, 2, and 3% are evaluated for in vitro antimicrobial activity against five genbank accessioned bacterial strains—Agrobacterium tumefaciens, Dickeya solani, Erwinia amylovora, Pseudomonas cichorii, and Serratia pylumthica—and two fungi, namely, Fusarium culmorum and Rhizoctonia solani. Through HPLC analysis we find that the most abundant quantified phenolic and flavonoid compounds of acetone extract (mg/100 g) are salicylic acid (9.49), vanillic acid (4.78), rutin (4702.58), and myricetin (1386.62). Wood treated with the extract at 2% and 3% show no growth of A. tumefaciens, E. amylovora, and P. cichorii. Use of the extract at 3% causes inhibition of fungal mycelia of F. culmorum and R. solani by 84.07% and 67.03%, respectively. In conclusion, potent antifungal and antibacterial activity against plant pathogens is found when an acetone extract of W. somnifera fruits is applied to wood samples. Full article
(This article belongs to the Special Issue Green Separation and Extraction Processes)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Antibacterial activity of wood treated with acetone extracts of <span class="html-italic">Withania somnifera</span>. (<b>A</b>) <span class="html-italic">Agrobacterium tumefaciens</span>; (<b>B</b>) <span class="html-italic">Dickeya solani</span>; (<b>C</b>) <span class="html-italic">Erwinia amylovora</span>; (<b>D</b>) <span class="html-italic">Pseudomonas cichorii</span>; (<b>E</b>) <span class="html-italic">Serratia pylumthica</span>. C indicates control treatment (10% DMSO); 1, 2, and 3 indicate 1%, 2%, and 3% concentrated acetone extract.</p> Full article ">Figure 2
<p>Antifungal activity of the treated wood with <span class="html-italic">Withania somnifera</span> fruit acetone extract. (<b>A</b>) <span class="html-italic">Fusarium culmorum;</span> (<b>B</b>) <span class="html-italic">Rhizoctonia solani.</span></p> Full article ">Figure 3
<p>HPLC chromatogram of phenolic/caffeine (<b>A</b>) and flavonoid (<b>B</b>) compounds identified in acetone extracts of <span class="html-italic">Withania somnifera</span> fruits.</p> Full article ">Figure 3 Cont.
<p>HPLC chromatogram of phenolic/caffeine (<b>A</b>) and flavonoid (<b>B</b>) compounds identified in acetone extracts of <span class="html-italic">Withania somnifera</span> fruits.</p> Full article ">
9 pages, 2113 KiB  
Article
Co-Firing of Sawdust and Liquid Petroleum Gas in the Application of a Modified Rocket Stove
by Paisan Comsawang, Suwat Nanetoe and Nitipong Soponpongpipat
Processes 2020, 8(1), 112; https://doi.org/10.3390/pr8010112 - 15 Jan 2020
Cited by 3 | Viewed by 4575
Abstract
The heating rate, firepower, and thermal efficiency of a modified rocket stove using sawdust and liquid petroleum gas (LPG) as co-firing fuel were investigated. Three modified rocket stoves with a height of 400 mm and outside diameters of 225, 385, and 550 mm [...] Read more.
The heating rate, firepower, and thermal efficiency of a modified rocket stove using sawdust and liquid petroleum gas (LPG) as co-firing fuel were investigated. Three modified rocket stoves with a height of 400 mm and outside diameters of 225, 385, and 550 mm were tested. It was found that there was an insignificant difference in heating rate and firepower when stoves were tested without co-firing with LPG. In this case, the stove heating rate was in the range of 1.49–1.55 °C/min. When LPG was used, the heating rate tended to linearly increase with the increase of LPG flow rate. The heating rate was in range of 2.42–2.80, 2.63–3.27, and 3.07–4.22 °C/min when LPG consumption rates were 2.38 × 10−5, 3.33 × 10−5, and 5.00 × 10−5 kg/s, respectively. The slight increase of stove heating rate and firepower was seen when the stove diameter was increased from 225 to 385 mm. The increase of stove diameter from 385 to 550 mm resulted in a huge increase of heating rate and firepower. Thermal efficiency of the sawdust stove without LPG decreased from 17.90% to 9.97% when the stove diameter was increased from 225 to 550 mm. For co-firing of sawdust and LPG, the increase of LPG flow rate from 2.38 × 10−5 to 5 × 10−5 kg/s caused the linear increase of thermal efficiency from 20.27% to 33.80%, 29.36% to 38.89%, and 25.25% to 36.39% for the stove with diameters of 225, 385, and 550 mm., respectively. Full article
(This article belongs to the Special Issue Biomass Processing and Conversion Systems)
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Graphical abstract
Full article ">Figure 1
<p>Stove setup.</p> Full article ">Figure 2
<p>Relationship between stove heating rate and stove diameter.</p> Full article ">Figure 3
<p>Relationship between stove heating rate and liquid petroleum gas (LPG) flow rate.</p> Full article ">Figure 4
<p>Relationship between firepower and stove diameter.</p> Full article ">Figure 5
<p>Relationship between firepower and LPG flow rate.</p> Full article ">Figure 6
<p>Sawdust layer in stove.</p> Full article ">Figure 7
<p>Relationship between stove efficiency and stove diameter.</p> Full article ">Figure 8
<p>Relationship between stove efficiency and LPG flow rate.</p> Full article ">
12 pages, 819 KiB  
Article
Evaluation of Different Treatment Processes for Landfill Leachate Using Low-Cost Agro-Industrial Materials
by Tawfiq J. H. Banch, Marlia M. Hanafiah, Abbas F. M. Alkarkhi, Salem S. A. Amr and Nurul U. M. Nizam
Processes 2020, 8(1), 111; https://doi.org/10.3390/pr8010111 - 15 Jan 2020
Cited by 24 | Viewed by 4240
Abstract
Leachate is a complex liquid that is often produced from landfills, and it contains hazardous substances that may endanger the surrounding environment if ineffectively treated. In this work, four leachate treatment applications were examined: combined leachate/palm oil mill effluent (POME) (LP), leachate/tannin (LT), [...] Read more.
Leachate is a complex liquid that is often produced from landfills, and it contains hazardous substances that may endanger the surrounding environment if ineffectively treated. In this work, four leachate treatment applications were examined: combined leachate/palm oil mill effluent (POME) (LP), leachate/tannin (LT), pre-(leachate/tannin) followed by post-(leachate/POME) (LT/LP), and pre-(leachate/POME) followed by post-(leachate/tannin) (LP/LT). The aim of this work is to evaluate and compare the performance of these treatment applications in terms of optimizing the physicochemical parameters and removing heavy metals from the leachate. The highest efficiency for the optimization of the most targeted physicochemical parameters and the removal of heavy metals was with the LP/LT process. The results are indicative of three clusters. The first cluster involves raw leachate (cluster 1), the second contains LP and LP/LT (cluster 2), and the third also consists of two treatment applications, namely, LT and LT/LP (cluster 3). The results demonstrate that LP/LT is the most appropriate method for leachate treatment using low-cost agro-industrial materials. Full article
(This article belongs to the Special Issue Wastewater Treatment Processes)
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<p>Reduction efficiencies for the physicochemical parameters in the four treatment applications.</p> Full article ">Figure 2
<p>Removal efficiencies for the heavy metals in the four treatment applications.</p> Full article ">Figure 3
<p>Cluster dendrogram of the four treatment applications based on the residual concentrations of heavy metals and the physicochemical parameters.</p> Full article ">
13 pages, 6462 KiB  
Article
Optimization Design and Analysis of Polymer High Efficiency Mixer in Offshore Oil Field
by Zheng Shu, Shijie Zhu, Jian Zhang, Wensen Zhao and Zhongbin Ye
Processes 2020, 8(1), 110; https://doi.org/10.3390/pr8010110 - 15 Jan 2020
Cited by 3 | Viewed by 2897
Abstract
The degree of polymer-water mixing in high-pressure pipelines on offshore oilfields usually influences the polymer solution’s performance. To realize efficient mixing of the polymer mother liquor with dilution water in the high-pressure pipeline, a high-efficiency mixer is designed and optimized. The designed mixer [...] Read more.
The degree of polymer-water mixing in high-pressure pipelines on offshore oilfields usually influences the polymer solution’s performance. To realize efficient mixing of the polymer mother liquor with dilution water in the high-pressure pipeline, a high-efficiency mixer is designed and optimized. The designed mixer consists of four parts: a T-shaped pipe as the main body, an inlet flow-splitting plate, a stainless-steel flow-guiding tube, and an outlet flow-splitting plate. Mathematical models are built by using computational fluid dynamics (CFD) and the mixing effects are compared by using Fluent. The research results show that compared with conventional T-shaped mixers, the designed high-efficiency mixer has better mixing performance and increases the mixing rate to 80%. To optimize the mixing rate, the length of the stainless-steel tube is increased and the tube is perforated to guide the flow. The result shows that boring holes along straight lines around the tube can achieve good optimization effect and increase the mixing rate to 95%. The designed high-efficiency mixer can effectively improve the dissolving efficiency and solve problems in polymer-water mixing in the high-pressure pipeline. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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<p>The design diagram of the high efficiency mixer.</p> Full article ">Figure 2
<p>Physical model of high efficiency mixer.</p> Full article ">Figure 3
<p>Mesh generation.</p> Full article ">Figure 4
<p>Mesh quality analysis chart.</p> Full article ">Figure 5
<p>Comparison of mixing effects at the X section of two model mixers.</p> Full article ">Figure 6
<p>Mixing characteristics at Y–Z sections.</p> Full article ">Figure 7
<p>Distribution of volume fraction of polymer on different positions of X–Y axis.</p> Full article ">Figure 8
<p>Model of improved high-efficiency mixer.</p> Full article ">Figure 9
<p>Simulated mixing effect of the optimized mixer.</p> Full article ">Figure 9 Cont.
<p>Simulated mixing effect of the optimized mixer.</p> Full article ">Figure 10
<p>The simulation mixing result of Scheme B.</p> Full article ">Figure 11
<p>Mixing effect of different hole-boring schemes (Left is a; Right is b).</p> Full article ">
17 pages, 3815 KiB  
Article
Short-Term Wind Power Prediction Based on Improved Grey Wolf Optimization Algorithm for Extreme Learning Machine
by Jiale Ding, Guochu Chen and Kuo Yuan
Processes 2020, 8(1), 109; https://doi.org/10.3390/pr8010109 - 15 Jan 2020
Cited by 33 | Viewed by 3184
Abstract
In order to improve the accuracy of wind power prediction and ensure the effective utilization of wind energy, a short-term wind power prediction model based on variational mode decomposition (VMD) and an extreme learning machine (ELM) optimized by an improved grey wolf optimization [...] Read more.
In order to improve the accuracy of wind power prediction and ensure the effective utilization of wind energy, a short-term wind power prediction model based on variational mode decomposition (VMD) and an extreme learning machine (ELM) optimized by an improved grey wolf optimization (GWO) algorithm is proposed. The original wind power sequence is decomposed into series of modal components with different center frequencies by the VMD method and some new sequences are obtained by phase space reconstruction (PSR). Then, the ELM model is established for different new time series, and the improved GWO algorithm is used to optimize its parameters. Finally, the output results are weighted and merged as the final predicted value of wind power. The root-mean-square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) of the proposed VMD-improved GWO-ELM prediction model in the paper are 5.9113%, 4.6219%, and 13.01% respectively, which are better than these of ELM, back propagation (BP), and the improved GWO-ELM model. The simulation results show that the proposed model has higher prediction accuracy than other models in short-term wind power prediction. Full article
(This article belongs to the Section Process Control and Monitoring)
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<p>Convergence factor comparison chart.</p> Full article ">Figure 2
<p>Short-term wind power prediction flow chart based on improved grey wolf optimization (GWO)- extreme learning machine (ELM) model.</p> Full article ">Figure 3
<p>Shubert function convergence curve.</p> Full article ">Figure 4
<p>Four classic test function convergence curves.</p> Full article ">Figure 5
<p>100 KW medium-size wind turbines from a wind farm in Henan.</p> Full article ">Figure 6
<p>The flow chart of improved variational mode decomposition (VMD) decomposition.</p> Full article ">Figure 7
<p>Decomposition of VMD.</p> Full article ">Figure 8
<p>Three frequency waveform prediction sketch diagrams. (<b>a</b>) Low-frequency wind power prediction, (<b>b</b>) medium-frequency wind power prediction, and (<b>c</b>) high-frequency wind power prediction.</p> Full article ">Figure 9
<p>With/without high-frequency wave wind power prediction.</p> Full article ">Figure 10
<p>The comparison of different prediction results curve.</p> Full article ">
14 pages, 1996 KiB  
Article
Non-Linear Sliding Mode Controller for Photovoltaic Panels with Maximum Power Point Tracking
by Hina Gohar Ali, Ramon Vilanova Arbos, Jorge Herrera, Andrés Tobón and Julián Peláez-Restrepo
Processes 2020, 8(1), 108; https://doi.org/10.3390/pr8010108 - 14 Jan 2020
Cited by 34 | Viewed by 5271
Abstract
In this paper, nonlinear sliding mode control (SMC) techniques formulated for extracting maximum power from a solar photovoltaic (PV) system under variable environmental conditions employing the perturb and observe (P and O) maximum power point tracking (MPPT) technique are discussed. The PV system [...] Read more.
In this paper, nonlinear sliding mode control (SMC) techniques formulated for extracting maximum power from a solar photovoltaic (PV) system under variable environmental conditions employing the perturb and observe (P and O) maximum power point tracking (MPPT) technique are discussed. The PV system is connected with load through the boost converter. A mathematical model of the boost converter is derived first, and based on the derived model, a SMC is formulated to control the gating pulses of the boost converter switch. The closed loop system stability is verified through the Lyapunov stability theorem. The presented control scheme along with the solar PV system is simulated in MATLAB (matric laboratory) (SMC controller and PWM (Pulse Width Modulation) part) and PSIM (Power electronics simulations) (solar PV and MPPT algorithm) environments using the Simcoupler tool. The simulation results of the proposed controller (SMC) are compared with the classical proportional integral derivative (PID) control scheme, keeping system parameters and environmental parameters the same. Full article
(This article belongs to the Section Process Control and Monitoring)
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<p>System scheme based on a classical proportional integral derivative (PID) control.</p> Full article ">Figure 2
<p>System scheme based on the improved sliding mode controller (SMC).</p> Full article ">Figure 3
<p>Photovoltaic (PV) panel double-diode model representation.</p> Full article ">Figure 4
<p>Perturb and observe (P and O) algorithm.</p> Full article ">Figure 5
<p>(<b>a</b>) Profile of the PV panel voltage, (<b>b</b>) tracking response of the proposed PID controller, and (<b>c</b>) profile of the PV power extraction.</p> Full article ">Figure 6
<p>(<b>a</b>) Profile of the PV panel voltage, (<b>b</b>) tracking response of the proposed SMC controller, and (<b>c</b>) profile of power extraction.</p> Full article ">Figure 6 Cont.
<p>(<b>a</b>) Profile of the PV panel voltage, (<b>b</b>) tracking response of the proposed SMC controller, and (<b>c</b>) profile of power extraction.</p> Full article ">Figure 7
<p>Reference, PID, and SMC PV voltage curve.</p> Full article ">Figure 8
<p>Reference, PID, and SMC PV power curve.</p> Full article ">Figure 9
<p>PID and SMC PV tracking error curve.</p> Full article ">
22 pages, 3691 KiB  
Article
A Two-Stage Optimal Scheduling Model of Microgrid Based on Chance-Constrained Programming in Spot Markets
by Jiayu Li, Caixia Tan, Zhongrui Ren, Jiacheng Yang, Xue Yu and Zhongfu Tan
Processes 2020, 8(1), 107; https://doi.org/10.3390/pr8010107 - 14 Jan 2020
Cited by 5 | Viewed by 2848
Abstract
Aimed at the coordination control problem of each unit caused by microgrid participation in the spot market and considering the randomness of wind and solar output and the uncertainty of spot market prices, a day-ahead real-time two-stage optimal scheduling model for microgrid was [...] Read more.
Aimed at the coordination control problem of each unit caused by microgrid participation in the spot market and considering the randomness of wind and solar output and the uncertainty of spot market prices, a day-ahead real-time two-stage optimal scheduling model for microgrid was established by using the chance-constrained programming theory. On this basis, an improved particle swarm optimization (PSO) algorithm based on stochastic simulation technology was used to solve the problem and the effect of demand side management and confidence level on scheduling results is discussed. The example results verified the correctness and effectiveness of the proposed model, which can provide a theoretical basis in terms of reasonably coordinating the output of each unit in the microgrid in the spot market. Full article
(This article belongs to the Special Issue Advances in Sustainable Supply Chains)
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<p>The structure of the microgrid system.</p> Full article ">Figure 2
<p>The flow chart of the microgrid participating in the spot market.</p> Full article ">Figure 3
<p>The flow chart of the algorithm solution.</p> Full article ">Figure 4
<p>The scheduling revenue convergence curve of the microgrid.</p> Full article ">Figure 5
<p>Spot market electricity price forecast chart.</p> Full article ">Figure 6
<p>The comparison of the microgrid operation plan and electricity price in the day-ahead market.</p> Full article ">Figure 7
<p>Real-time market microgrid operation plan.</p> Full article ">Figure 8
<p>The comparison of the two-stage optimal scheduling results.</p> Full article ">Figure 9
<p>The comparison of day-ahead scheduling of the microgrid before and after demand side management.</p> Full article ">Figure 10
<p>The comparison of the two-stage optimal scheduling results (demand side management).</p> Full article ">Figure 11
<p>The curve diagram of the microgrid’s day-ahead market returns under different levels.</p> Full article ">Figure 12
<p>The curve diagram of the microgrid’s real-time market returns under different levels.</p> Full article ">
12 pages, 1609 KiB  
Article
Physicochemical Properties of Guava Snacks as Affected by Drying Technology
by Yuri M. Leiton-Ramírez, Alfredo Ayala-Aponte and Claudia I. Ochoa-Martínez
Processes 2020, 8(1), 106; https://doi.org/10.3390/pr8010106 - 14 Jan 2020
Cited by 18 | Viewed by 6278
Abstract
Guava is widely consumed because of its agro-industrial use, and its antioxidant properties attributed to vitamin C and carotenoids content. However, it has a short shelf life. Guava has been dried by atomization, fluidized bed, lyophilization (FD) and convective drying (CD). CD requires [...] Read more.
Guava is widely consumed because of its agro-industrial use, and its antioxidant properties attributed to vitamin C and carotenoids content. However, it has a short shelf life. Guava has been dried by atomization, fluidized bed, lyophilization (FD) and convective drying (CD). CD requires long operation times and the product characteristics are not desirable. In contrast, FD produces high quality products, but requires long processing times, high energy consumption and high operation costs. As an alternative, the Refractance Window® (RW) drying is relatively simple and cheap technique. The objective of this study was to compare the effect of CD, FD and RW techniques, on the moisture content, water activity, color, porosity, volume change, vitamin C and carotenoids content in guava samples. The samples dried by RW required less time to reduce the moisture content and exhibited smaller changes in color than CD or FD. There were greater losses of carotenoids and vitamin C when drying by CD whereas RW had similar losses than FD. Lyophilized products exhibited minor change in volume and greater porosity. RW results in better retention of properties, compared with other drying techniques. Based on this, RW is a promising technique for the development of guava snacks. Full article
(This article belongs to the Special Issue Drying Kinetics and Quality Control in Food Processing)
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<p>Acrylic mold for the preparation of slices of guava pure.</p> Full article ">Figure 2
<p>Refractance window equipment for drying guava slices.</p> Full article ">Figure 3
<p>Drying curves of guava samples using convective drying (CD), freeze drying (FD) and refractance window drying (RW).</p> Full article ">Figure 4
<p>Effect of the drying method (CD, FD and RW) on the water activity of guava samples.</p> Full article ">Figure 5
<p>Total color change of guava samples using different drying methods (CD, FD and RW).</p> Full article ">
16 pages, 2957 KiB  
Article
A Dynamic Active Safe Semi-Supervised Learning Framework for Fault Identification in Labeled Expensive Chemical Processes
by Xuqing Jia, Wende Tian, Chuankun Li, Xia Yang, Zhongjun Luo and Hui Wang
Processes 2020, 8(1), 105; https://doi.org/10.3390/pr8010105 - 13 Jan 2020
Cited by 8 | Viewed by 3512
Abstract
A novel active semi-supervised learning framework using unlabeled data is proposed for fault identification in labeled expensive chemical processes. A principal component analysis (PCA) feature selection strategy is first given to calculate the weight of the variables. Secondly, the identification model is trained [...] Read more.
A novel active semi-supervised learning framework using unlabeled data is proposed for fault identification in labeled expensive chemical processes. A principal component analysis (PCA) feature selection strategy is first given to calculate the weight of the variables. Secondly, the identification model is trained based on the obtained key process variables. Thirdly, the pseudo label confidence of identification model is dynamically optimized with an historical, current, and future pseudo label confidence mean. To increase the upper limit of the identification model that is self-learning with high entropy process data, active learning is used to identify process data and diagnosis fault causes by ontology. Finally, a PCA-dynamic active safe semi-supervised support vector machine (PCA-DAS4VM) for fault identification in labeled expensive chemical processes is built. The application in the Tennessee Eastman (TE) process shows that this hybrid technology is able to: (i) eliminate chemical process noise and redundant process variables simultaneously, (ii) combine historical pseudo label confidence with future pseudo label confidence to improve the identification accuracy of abnormal working conditions, (iii) efficiently select and diagnose high entropy unlabeled process data, and (iv) fully utilize unlabeled data to enhance the identification performance. Full article
(This article belongs to the Special Issue Process Optimization and Control)
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<p>The framework of the PCA-dynamic active safe semi-supervised support vector machine (PCA-DAS4VM) based fault identification method.</p> Full article ">Figure 2
<p>S4VM fault identification diagram focusing on multiple low density boundaries.</p> Full article ">Figure 3
<p>Flow chart of Tennessee Eastman (TE) process.</p> Full article ">Figure 4
<p>Principal component variance percent explained for fault 4.</p> Full article ">Figure 5
<p>The principal component eigenvalues of fault 4.</p> Full article ">Figure 6
<p>Weight of the key measurement variables for fault 4.</p> Full article ">Figure 7
<p>Key variables selected for each of the 20 TE faults.</p> Full article ">Figure 8
<p>Accuracy of PCA-DAS4VM under different numbers of labeled data.</p> Full article ">Figure 9
<p>Accuracy of PCA-DAS4VM under different percentages of unlabeled data.</p> Full article ">Figure 10
<p>F1 scores for PCA-S4VM, DAS4VM, and PCA-DAS4VM models.</p> Full article ">Figure 11
<p>False positive rate (FPR) for PCA-S4VM, DAS4VM, and PCA-DAS4VM models.</p> Full article ">Figure 12
<p>FDR for PCA-S4VM, DAS4VM, and PCA-DAS4VM models.</p> Full article ">Figure 13
<p>Accuracy rate for dynamic sparse stacked auto-encoders (DSSAE), ALSemiFDA, and PCA-DAS4VM models.</p> Full article ">Figure 14
<p>Graphical scenario object model of the TE process based on ontology.</p> Full article ">Figure 15
<p>Fault 4 graphical scenario object model.</p> Full article ">
14 pages, 4461 KiB  
Article
Ultrasonically Induced Sulfur-Doped Carbon Nitride/Cobalt Ferrite Nanocomposite for Efficient Sonocatalytic Removal of Organic Dyes
by Surabhi Kamal, Guan-Ting Pan, Siewhui Chong and Thomas Chung-Kuang Yang
Processes 2020, 8(1), 104; https://doi.org/10.3390/pr8010104 - 13 Jan 2020
Cited by 22 | Viewed by 4509
Abstract
The sulfur-doped carbon nitride/cobalt ferrite nanocomposite (SCN/CoFe2O4) was prepared via ultrasonication and studied for the sonocatalytic degradation of wastewater organic dye pollutants including methylene blue, rhodamine B, and Congo red. The X-ray photoelectron spectroscopy confirmed the presence and atomic [...] Read more.
The sulfur-doped carbon nitride/cobalt ferrite nanocomposite (SCN/CoFe2O4) was prepared via ultrasonication and studied for the sonocatalytic degradation of wastewater organic dye pollutants including methylene blue, rhodamine B, and Congo red. The X-ray photoelectron spectroscopy confirmed the presence and atomic ratios of S, C, N, Co, Fe, and O elements and their corresponding bonds with Co2+ and Fe3+ cations. The nanocomposite was found to have aggregated nanoparticles on a sheet-like structure. The bandgap energy was estimated to be 1.85 eV. For the sonocatalytic degradation of 25-ppm methylene blue at 20 kHz, 1 W and 50% amplitude, the best operating condition was determined to be 1 g/L of catalyst dosage and 4 vol % of hydrogen peroxide loading. Under this condition, the sonocatalytic removal efficiency was the highest at 96% within a reaction period of 20 min. SCN/CoFe2O4 outperformed SCN and CoFe2O4 by 2.2 and 6.8 times, respectively. The SCN/CoFe2O4 nanocomposite was also found to have good reusability with a drop of only 7% after the fifth cycle. However, the degradation efficiencies were low when tested with rhodamine B and Congo red due to difference in dye sizes, structural compositions, and electric charges. Full article
(This article belongs to the Special Issue Advanced Liquid Waste and Gas Waste Treatment Processes)
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<p>(<b>a</b>) XRD patterns of CoFe<sub>2</sub>O<sub>4</sub>, SCN, and SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite; (<b>b</b>) FT-IR spectra of CoFe<sub>2</sub>O<sub>4</sub>, SCN, and SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite.</p> Full article ">Figure 2
<p>FESEM (<b>a</b>) and TEM (<b>b</b>) of SCN; FESEM (<b>c</b>) and TEM (<b>d</b>) of CoFe<sub>2</sub>O<sub>4</sub>; FESEM (<b>e</b>) and TEM (<b>f</b>) of SCN/CoFe<sub>2</sub>O<sub>4</sub>.</p> Full article ">Figure 3
<p>(<b>a</b>) UV-Vis spectra of SCN, CoFe<sub>2</sub>O<sub>4</sub>, and SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite; (<b>b</b>) (αhν)<sup>2</sup> vs. bandgap energy.</p> Full article ">Figure 4
<p>Photoluminescence spectra of SCN, CoFe<sub>2</sub>O<sub>4</sub> and SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite.</p> Full article ">Figure 5
<p>The XPS spectra of (<b>a</b>) C 1s; (<b>b</b>) N 1s; (<b>c</b>) S 2p; (<b>d</b>) Co 2p; (<b>e</b>) Fe 2p; (<b>f</b>) O 1s.</p> Full article ">Figure 6
<p>Effect of SCN/CoFe<sub>2</sub>O<sub>4</sub> dosage on the catalytic degradation of MB without ultrasonication. Experimental conditions: [MB] = 25 ppm, [catalyst] = 0–1.5 g/L, [H<sub>2</sub>O<sub>2</sub>] = 4 vol %.</p> Full article ">Figure 7
<p>Effect of H<sub>2</sub>O<sub>2</sub> loading on the catalytic degradation of MB without ultrasonication. Experimental conditions: [MB] = 25 ppm, [catalyst] = 1 g/L mg, [H<sub>2</sub>O<sub>2</sub>] = 0–6 vol %.</p> Full article ">Figure 8
<p>(<b>a</b>) Change in concentration of MB as a function of ultrasonication time; (<b>b</b>) ln(C<sub>0</sub>/C) versus ultrasonication time. Experimental conditions: [MB] = 25 ppm, [sonocatalyst] = 1 g/L, [H<sub>2</sub>O<sub>2</sub>] = 4 vol %.</p> Full article ">Figure 9
<p>Effect of the type of organic dye on sonodegradation. Experimental conditions: [Dye concentration] = 25 ppm, [sonocatalyst] = 1 g/L, [H<sub>2</sub>O<sub>2</sub>] = 4 vol %.</p> Full article ">Figure 10
<p>(<b>a</b>) Recyclability of SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite; (<b>b</b>) FT-IR of recovered SCN/CoFe<sub>2</sub>O<sub>4</sub> nanocomposite after the third cycle.</p> Full article ">
11 pages, 2927 KiB  
Article
Hygro-Thermo-Mechanical Responses of Balsa Wood Core Sandwich Composite Beam Exposed to Fire
by Luan TranVan, Vincent Legrand, Pascal Casari, Revathy Sankaran, Pau Loke Show, Aydin Berenjian and Chyi-How Lay
Processes 2020, 8(1), 103; https://doi.org/10.3390/pr8010103 - 13 Jan 2020
Cited by 4 | Viewed by 4894
Abstract
In this study, the hygro–thermo–mechanical responses of balsa core sandwich structured composite was investigated by using experimental, analytical and numerical results. These investigations were performed on two types of specimen conditions: dry and moisture saturation sandwich composite specimens that are composed of E-glass/polyester [...] Read more.
In this study, the hygro–thermo–mechanical responses of balsa core sandwich structured composite was investigated by using experimental, analytical and numerical results. These investigations were performed on two types of specimen conditions: dry and moisture saturation sandwich composite specimens that are composed of E-glass/polyester skins bonded to a balsa core. The wet specimens were immersed in distilled water at 40 °C until saturated with water. The both dry and wet sandwich composite specimens were heated by fire. The mass loss kinetic and the mechanical properties were investigated by using a cone calorimeter following the ISO 5660 standard and three-point bending mechanical test device. Experimental data show that the permeability and fire resistance of the sandwich structure are controlled by two composite skins. Obtained results allow us to understand the Hygro–Thermo–Mechanical Responses of the sandwich structured composite under application conditions. Full article
(This article belongs to the Special Issue Green Technologies: Bridging Conventional Practices and Industry 4.0)
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<p>The studied E-glass/polyester/balsa sandwich composite beam specimen (<b>a</b>). Dimensions were illustrated the chosen directions of the moisture and heat flux. D<sub>1</sub>, D<sub>2</sub> and D<sub>3 </sub>are, respectively, the transverse directions and the thickness direction (<b>b</b>).</p> Full article ">Figure 2
<p>Diagram of the ATLAS cone calorimetry: holder of the test specimen (<b>a</b>), conical heater (<b>b</b>).</p> Full article ">Figure 3
<p>Sketch of the supporting (<b>a</b>) and the device (<b>b</b>) for the three-point bending tests of sandwich beams.</p> Full article ">Figure 4
<p>Diffusion kinetics of moisture at 40 °C in a sandwich beam (<b>a</b>) and a bi-blade (one skin and a core) (<b>b</b>).</p> Full article ">Figure 5
<p>Mass loss curves as a function of fire exposure time for dry E-glass polyester single skin (<b>a</b>) and sandwich composite beam (<b>b</b>) from cone calorimetry measurements at 750 °C.</p> Full article ">Figure 6
<p>Cross-sectional view of the during fire exposure of the dry specimens (<b>a</b>) and the moisture saturation specimens (<b>b</b>).</p> Full article ">Figure 7
<p>Three-point bending test: Force—displacement curve of the dry and water saturation sandwich specimens (<b>a</b>), failure mode of dry sandwich specimen (<b>b</b>) and water saturation sandwich specimen (<b>c</b>).</p> Full article ">Figure 8
<p>The curve of the <span class="html-italic">δ</span>/(<span class="html-italic">FL</span>) = <span class="html-italic">L</span><sup>2</sup> to determine the Young’s modulus (<span class="html-italic">E</span>) and the shear modulus (<span class="html-italic">G</span>).</p> Full article ">Figure 9
<p>Post-residual flexural mechanical responses as a function of fire exposure time: normalized residual force (<b>a</b>) and normalized residual modulus (<b>b</b>).</p> Full article ">Figure 10
<p>Cross-section of the sandwich structured composite beam after 100 s exposed to fire for the dry specimen (<b>a</b>) and the moisture saturation specimen (<b>b</b>).</p> Full article ">
7 pages, 1178 KiB  
Article
The Effects of Lung-Moistening Herbal Medicines on Bleomycin-Induced Pulmonary Fibrosis Mouse Model
by Junmo Ahn, Hyejin Joo, Jihye Park, Jae-Woo Park, Kwan-Il Kim, Hee-Jae Jung, Youngmin Bu and Beom-Joon Lee
Processes 2020, 8(1), 102; https://doi.org/10.3390/pr8010102 - 12 Jan 2020
Cited by 5 | Viewed by 4842
Abstract
In traditional medicine, lung-moistening herbal medicines (LMHM) are regarded as a major option for treating symptoms of pulmonary fibrosis (PF) including dry cough and dyspnea. As PF agents are being applied to the development of lung cancer agents, PF and lung cancer are [...] Read more.
In traditional medicine, lung-moistening herbal medicines (LMHM) are regarded as a major option for treating symptoms of pulmonary fibrosis (PF) including dry cough and dyspnea. As PF agents are being applied to the development of lung cancer agents, PF and lung cancer are reported to have high pathological and pharmacological relationships. This study was proposed to identify candidates for the treatment of PF via investigating the effect of LMHM on PF mouse model. PF was induced by intratracheal instillation of bleomycin. Six water extracts of LMHM such as Farfarae Flos (FAF), Trichosanthis Semen (TRS), Lilii Bulbus (LIB), Adenophorae Radix (ADR), Asteris Radix (ASR), and Scrophulariae Radix (SCR) were prepared and administered (300 mg/kg) orally for 10 days after induction. The changes in body weight, histopathology, and immune cell of bronchoalveolar lavage fluid (BALF) were investigated. Among those, LIB and ADR significantly decreased the deposition of collagen and septal thickness of alveolar and terminal bronchiole. Moreover, SCR, TRS, LIB, and ADR decreased total cells, macrophages, and lymphocytes in BALF. Taken together, ADR and LIB could be the candidates to reduce PF. Further studies on their effects at different doses and analysis of their underlying molecular mechanisms are needed. Full article
(This article belongs to the Special Issue Cancer Systems Biology and Natural Products)
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<p>Effects of herbal medicines used to treat pulmonary fibrosis on Masson’s trichrome-stained left lung (10×, <b>A</b>), Hematoxylin-Eosin-stained lung sections (200×, <b>B</b>), Masson’s trichrome-stained lung sections (200×, <b>C</b>), body weight (<b>D</b>), Ashcroft score (<b>E</b>), and collagen fiber area of left lung (<b>F</b>). Scale bars are 1 mm (<b>A</b>) and 400 μm (<b>B</b>,<b>C</b>), respectively. FAF, Farfarae Flos; TRS, Trichosanthis Semen; LIB, Lilii Bulbus; ADR, Adenophorae Radix; ASR, Asteris Radix; SCR, Scrophulariae Radix. * represents statistical differences from control group (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p> Full article ">Figure 2
<p>Inflammatory cell counts in the Bronchoalveolar fluid of each group. The typical image of inflammatory cell distribution in each group (<b>A</b>), the graph of the total cell number (<b>B</b>), macrophage number (<b>C</b>), and lymphocyte number (<b>D</b>), respectively. The magnification of A is 200×. Scale bar is 400 μm. FAF, Farfarae Flos; TRS, Trichosanthis Semen; LIB, Lilii Bulbus; ADR, Adenophorae Radix; ASR, Asteris Radix; SCR, Scrophulariae Radix. * represents statistical differences from control group (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001).</p> Full article ">
14 pages, 3986 KiB  
Article
Acid-Base Flow Battery, Based on Reverse Electrodialysis with Bi-Polar Membranes: Stack Experiments
by Jiabing Xia, Gerhart Eigenberger, Heinrich Strathmann and Ulrich Nieken
Processes 2020, 8(1), 99; https://doi.org/10.3390/pr8010099 - 11 Jan 2020
Cited by 41 | Viewed by 8468
Abstract
Neutralization of acid and base to produce electricity in the process of reverse electrodialysis with bipolar membranes (REDBP) presents an interesting but until now fairly overlooked flow battery concept. Previously, we presented single-cell experiments, which explain the principle and discuss the potential of [...] Read more.
Neutralization of acid and base to produce electricity in the process of reverse electrodialysis with bipolar membranes (REDBP) presents an interesting but until now fairly overlooked flow battery concept. Previously, we presented single-cell experiments, which explain the principle and discuss the potential of this process. In this contribution, we discuss experiments with REDBP stacks at lab scale, consisting of 5 to 20 repeating cell units. They demonstrate that the single-cell results can be extrapolated to respective stacks, although additional losses have to be considered. As in other flow battery stacks, losses by shunt currents through the parallel electrolyte feed/exit lines increases with the number of connected cell units, whereas the relative importance of electrode losses decreases with increasing cell number. Experimental results are presented with 1 mole L−1 acid (HCl) and base (NaOH) for open circuit as well as for charge and discharge with up to 18 mA/cm2 current density. Measures to further increase the efficiency of this novel flow battery concept are discussed. Full article
(This article belongs to the Special Issue Electrolysis Processes)
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<p>Schematic of main ionic fluxes and electrode reactions of the REDBP (reverse electrodialysis with bipolar membranes) stack used, in the lower part during charge and in the upper part during discharge. Only one of several repeating cell units is shown between the electrode compartments. The respective electrode reactions during charge and discharge are indicated at the electrodes. CM: cation exchange membrane, AM: anion exchange membrane, BM: bipolar membrane.</p> Full article ">Figure 2
<p>Parallel flow concept for acid, base and salt solution through four repeating cell units in the middle of a stack. The black arrows indicate the flow directions of acid (HCl), of base (NaOH) and of salt solution (NaCl), and the colored arrows indicate the main fluxes of specific ions during discharge, also at OCV.</p> Full article ">Figure 3
<p>Subsequent cell frames for one repeating cell unit: (<b>a</b>) for up-flow of HCl, (<b>b</b>) for up-flow of NaOH and (<b>c</b>) for cross-flow of the NaCl solution.</p> Full article ">Figure 4
<p>Self-discharge test at 25 °C for different stack sizes and different acid and base concentrations. (<b>a</b>) 5-cell stack, 1M acid and base, (<b>b</b>) 10-cell stack, 1M acid and base, (<b>c</b>) 15-cell stack, 1M acid and base, (<b>d</b>) 20-cell stack, 1M acid and base, (<b>e</b>) 20-cell stack with 0.5 M acid/base concentration. OCV_Stack (black) has been measured between the electrodes, OCV_AllSCs (blue) between the first and the last repeating cell unit of the stack, OCV_5cells_1st (green solid) and OCV_5cells_2nd (green, dotted) have been measured across the first and second 5-cell unit.</p> Full article ">Figure 5
<p>(<b>a</b>) Simplified sketch of ionic shunt currents of H<sup>+</sup> (red arrows) and OH<sup>−</sup> (blue arrows) through the feed/exit lines of acid and base, and compensating ionic currents inside of four repeating cell units in the middle of the stack. The different arrow thickness indicates the increased shunt currents in the stack center. (<b>b</b>) Corresponding electric potential profiles φ across the repeating cell units (black) and in the acid (red) and the base feed/exit lines (blue). The arrows indicate the direction of the ion fluxes between cell compartments and feed/exit lines.</p> Full article ">Figure 6
<p>Charge and discharge behavior of a 20-cell stack with 1 M acid/base at 25 °C and 9 mA/cm<sup>2</sup> current density. The black line is the stack voltage measured across the electrodes; the blue line is the stack voltage across the 20-cell units. The voltages measured across the first repeating cell unit next to the electrode (red), the first 5-cell unit (green, solid) and the second 5-cell unit (green, dotted) are also shown.</p> Full article ">Figure 7
<p>Discharge voltages and net discharge power densities of the 20-cell stack with 1 M acid/base at 25 °C, plotted over discharge current density.</p> Full article ">Figure 8
<p>Current density measurements during charge and discharge with 1 M acid and base at 25 °C and 0.1 MPa at steady state. Current-voltage curves of positive slope represent charging, of negative slope discharging. Results for a 20-cell stack are shown in (<b>a</b>) and for a 15-cell stack in (<b>b</b>). Displayed are the measured voltages, VSC (across BP (bipolar membranes) of the first single cell, red), V5cell_2nd (across the second 5-cell unit, green dotted), V5cell_1st (across the first 5-cell unit, green solid), VAllSCs (across all cell units measured between Pt electrodes, blue) and VStack (stack voltage between electrodes, black).</p> Full article ">
16 pages, 2225 KiB  
Article
Assessment of the Usefulness of the Twin-Screw Press in Terms of the Pressing Efficiency and Antioxidant Properties of Apple Juice
by Kamil Wilczyński, Zbigniew Kobus, Rafał Nadulski and Marek Szmigielski
Processes 2020, 8(1), 101; https://doi.org/10.3390/pr8010101 - 11 Jan 2020
Cited by 9 | Viewed by 4375
Abstract
The paper presents the possibility of applying a twin-screw press for juice extraction from apples with different textural properties. The research was carried out with six different varieties; namely, Granny Smith, Modi, Ligol, Lobo, Boscop and Szampion. During the experiment, the following properties [...] Read more.
The paper presents the possibility of applying a twin-screw press for juice extraction from apples with different textural properties. The research was carried out with six different varieties; namely, Granny Smith, Modi, Ligol, Lobo, Boscop and Szampion. During the experiment, the following properties were measured: texture properties, pressing yield and polyphenolic content; and ascorbic acid content and antioxidant activity both in raw apples and apple juice. Based on the analysis, three hardness levels of apples can be distinguished, impacting the course of juice pressing in a twin-screw press (low hardness below 30 N, medium hardness 30–50 N and high hardness 50 N). The study showed that only high hardness apples are suitable for pressing on a twin-screw press. The mechanism by which texture properties influence the juice pressing process in the studied press was explained. It was further demonstrated that the hardness of apples has a positive impact on the degree of extraction of polyphenols and ascorbic acid into apple juice. This is caused by the different fracture patterns of tissues with different mechanical properties. High hardness apples (Granny Smith and Modi) were characterized by a considerably greater degree of bioactive substance extraction into juice than medium hardness apples. Full article
(This article belongs to the Collection Sustainable Food Processing Processes)
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Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Experimental flowchart.</p> Full article ">Figure 2
<p>Raw juice and filtered juice pressing yield depending on apple variety. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 for raw juices. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 for filtered juices.</p> Full article ">Figure 3
<p>The influence of apple variety on cloud value and total suspended solids in apple juice. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in the case of total suspended solids. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 for cloud value.</p> Full article ">Figure 4
<p>The influence of variety properties on total polyphenol content in fresh apples and in juice. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in apples. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in juices.</p> Full article ">Figure 5
<p>Chart illustrating fruit tissue disruption: (<b>A</b>) soft varieties; (<b>B</b>) hard varieties.</p> Full article ">Figure 6
<p>Influence of variety properties on total polyphenol content (TPC) in juice and in the sediment in juice. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in juices. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in sediment.</p> Full article ">Figure 7
<p>The effects of various varieties on content of ascorbic acid in the fresh apples and apple juice. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in apples. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in juices.</p> Full article ">Figure 8
<p>Influence of variety properties on antioxidant activity of juice and extracts from fresh apples. Different capital letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in apples. Different lowercase letters indicate values significantly different at <span class="html-italic">p</span> &lt; 0.05 in juices.</p> Full article ">
13 pages, 2089 KiB  
Article
Preparation of Sawdust-Filled Recycled-PET Composites via Solid-State Compounding
by Rula M. Allaf, Esraa Albarahmieh and Mohammad Futian
Processes 2020, 8(1), 100; https://doi.org/10.3390/pr8010100 - 11 Jan 2020
Cited by 16 | Viewed by 6426
Abstract
Recently, consumer markets have shown great interest in sustainable products. Considerable research efforts are headed towards developing biodegradable and recyclable polymers and composites. In this study, the fabrication of a wood–plastic composite (WPC) via solid state compounding has been examined. Polyethylene terephthalate (PET) [...] Read more.
Recently, consumer markets have shown great interest in sustainable products. Considerable research efforts are headed towards developing biodegradable and recyclable polymers and composites. In this study, the fabrication of a wood–plastic composite (WPC) via solid state compounding has been examined. Polyethylene terephthalate (PET) and wood sawdust waste as major components of waste and challenging materials for the manufacturing of WPCs have been explored. Furthermore, the addition of poly(ε-caprolactone) as a biodegradable plasticizing agent was investigated. Composite powders were prepared by cryogenic solid-state milling (cryomilling) according to a statistical mixture design. Mechanical and water absorption properties were inspected on film samples obtained by hot pressing. Different formulations resulted in a variety of colors, textures, water interactions and mechanical properties. A sawdust content of approximately 25 vol.% was optimal for the best combination of properties. The results indicated that cryomilling is technically advantageous in the production of WPCs. Full article
(This article belongs to the Special Issue Green Synthesis Processes of Polymers & Composites)
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<p>Effect of wood content (0–60 vol.%) on recycled-PET wood plastic composite (rPET WPC) color. SD = sawdust.</p> Full article ">Figure 2
<p>Sample stress–strain curves of rPET-based composites filled with 10 vol.%, 30 vol.% and 50 vol.% of SD, with and without the addition of PCL (30 vol.%), noted as PCL/SD <sub>PCL%/SD%</sub>. Inset figure presents a magnification of the small strain region.</p> Full article ">Figure 3
<p>Tensile properties of rPET-based composites: (<b>a</b>) Young’s modulus, (<b>b</b>) tensile strength, and (<b>c</b>) ductility as function of PCL and SD contents. Dotted lines represent polynomial (<b>a</b>,<b>b</b>) and exponential (<b>c</b>) fits. Error bars are shown in one direction only.</p> Full article ">Figure 4
<p>Mixture response surface and contour plots for effects of composition on rPET WPC mechanical properties: (<b>a</b>) tensile modulus, (<b>b</b>) tensile strength, and (<b>c</b>) ductility. Design space and design points are shown within the solid grey outline on the simplex coordinate system.</p> Full article ">Figure 5
<p>Scatter plot of (<b>a</b>) water uptake (WU%) and (<b>b</b>) thickness swelling (TS%) for samples as function of SD content.</p> Full article ">
15 pages, 5024 KiB  
Article
Influence of Eccentricity on Hydrodynamic Characteristics of Nuclear Reactor Coolant Pump under Different Cavitation Conditions
by Yuanyuan Zhao, Bin Lin, Xiuli Wang, Rongsheng Zhu and Qiang Fu
Processes 2020, 8(1), 98; https://doi.org/10.3390/pr8010098 - 10 Jan 2020
Cited by 5 | Viewed by 2772
Abstract
In order to study the influence of eccentricity on hydrodynamic characteristics of nuclear reactor coolant pump under different cavitation conditions, five different schemes were obtained by analyzing and optimizing the existing structural schemes. Based on the RNG k-ε model (Renormalization Group with k-epsilon [...] Read more.
In order to study the influence of eccentricity on hydrodynamic characteristics of nuclear reactor coolant pump under different cavitation conditions, five different schemes were obtained by analyzing and optimizing the existing structural schemes. Based on the RNG k-ε model (Renormalization Group with k-epsilon turbulence models) and two-fluid two-phase flow model, the unsteady numerical analysis and test verification of different designed schemes are carried out by using the flow field software ANSYS CFX. The results of research show that different eccentricities will affect the nuclear reactor coolant pump’s head under different cavitation conditions, and the corresponding head in the scheme with the eccentricity of 5mm under the fracture cavitation condition is lower than that of the other schemes. When the impeller rotates at a certain angle from the initial position under critical and severe cavitation conditions, the radial force acting on the rotor system will fluctuate greatly. Under the condition of fracture cavitation, the radial force changed periodically and the resultant force value is small. Compared to the original scheme, the peak value of radial force is 6° clockwise after eccentricity of the impeller appeared. With the aggravation of cavitation condition, the axial force value of impeller decreases, but the corresponding amplitude of the impeller increases. Under critical and severe cavitation conditions, the maximum axial force amplitude of the nuclear reactor coolant pump appears in the two times blade frequency, and in the broken cavitation condition, the maximum axial force amplitude appears at the shaft frequency. When the eccentricity is 20 mm, the axial force fluctuates most under critical and severe cavitation conditions, and when the eccentricity is 10 mm, the corresponding axial force is smaller than that of the original scheme. When the eccentricity is 5 mm, the axial force on the impeller is the smallest, but the amplitude is the largest under the condition of fracture cavitation. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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<p>The optimized compensation scheme.</p> Full article ">Figure 2
<p>The eccentricity scheme of the nuclear reactor coolant pump.</p> Full article ">Figure 3
<p>3D modeling and grid of the water body of the nuclear reactor coolant pump.</p> Full article ">Figure 4
<p>The head for each scheme.</p> Full article ">Figure 5
<p>The testing site and comparison between the experimental results and the simulation results.</p> Full article ">Figure 5 Cont.
<p>The testing site and comparison between the experimental results and the simulation results.</p> Full article ">Figure 6
<p>The change curves of the head ((<b>a</b>–<b>c</b>) represent conditions with inlet total pressure of 140 kPa, 110 kPa, and 100 kPa respectively).</p> Full article ">Figure 6 Cont.
<p>The change curves of the head ((<b>a</b>–<b>c</b>) represent conditions with inlet total pressure of 140 kPa, 110 kPa, and 100 kPa respectively).</p> Full article ">Figure 7
<p>The vapor phase volume fraction diagram of three different inlet pressure condition under eccentric e = 0 mm (<b>a</b>–<b>c</b>) represent conditions with inlet total pressure of 140 kPa, 110 kPa and 100 kPa respectively).</p> Full article ">Figure 8
<p>The hierarchical graph under the inlet total pressure being140 kPa.</p> Full article ">Figure 9
<p>The polar diagram of the resultant of radial force distribution on the impeller.</p> Full article ">Figure 9 Cont.
<p>The polar diagram of the resultant of radial force distribution on the impeller.</p> Full article ">Figure 10
<p>The time-domain diagram of the axial force of a nuclear reactor coolant pump impeller.</p> Full article ">Figure 11
<p>The frequency-domain diagram of the axial force of the impeller in the pump.</p> Full article ">
11 pages, 693 KiB  
Article
Drying Kinetics, Grinding Characteristics, and Physicochemical Properties of Broccoli Sprouts
by Dariusz Dziki, Ewa Habza-Kowalska, Urszula Gawlik-Dziki, Antoni Miś, Renata Różyło, Zbigniew Krzysiak and Waleed H. Hassoon
Processes 2020, 8(1), 97; https://doi.org/10.3390/pr8010097 - 10 Jan 2020
Cited by 10 | Viewed by 5292
Abstract
In this study, we studied the drying process, grinding characteristics and physicochemical characteristics of broccoli sprouts (BS). The seeds of broccoli were germinated at 20 °C for 3 and 6 days. Then, the seeds were air- and freeze-dried, and the Page model was [...] Read more.
In this study, we studied the drying process, grinding characteristics and physicochemical characteristics of broccoli sprouts (BS). The seeds of broccoli were germinated at 20 °C for 3 and 6 days. Then, the seeds were air- and freeze-dried, and the Page model was used for prediction of drying kinetics of broccoli sprouts. It was observed that the drying time of BS decreased about twofold as the air-drying temperature increased from 40 to 80 °C. An increasing the air-drying temperature from 40 to 80 °C decreased the drying time by approximately twofold. Freeze-drying of sprouts took the longest drying time. Germination of seeds significantly decreased the value of grinding energy requirements, and the ground sprouts exhibited a different grinding pattern in comparison to ground non-germinated seeds. In terms of color parameters, the highest lightness and yellowness were found for freeze-dried sprouts. Redness and yellowness of sprouts increased with an increase in the air-drying temperature. The lowest total color difference was obtained for the freeze-dried sprouts. Higher drying temperature resulted in lower total phenolics content (TPC) and decreased antioxidant activity (AA). The highest TPC and AA were observed in air-dried sprouts (40 °C) and freeze-dried sprouts after 6 days of germination. Full article
(This article belongs to the Collection Sustainable Food Processing Processes)
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<p>Drying curves of dried broccoli sprouts with experimental and predicted data based on the Page model: <span class="html-italic">MR</span>—moisture ratio, SPD40, SPD60 and SPD80—sprouts air-dried at 40, 60 and 80 °C, respectively, SPF—freeze-dried sprouts, (<b>A</b>)—after 3 days of germination and (<b>B</b>)—after 6 days of germination.</p> Full article ">
16 pages, 5455 KiB  
Article
Hierarchical Cs–Pollucite Nanozeolite Modified with Novel Organosilane as an Excellent Solid Base Catalyst for Claisen–Schmidt Condensation of Benzaldehyde and Acetophenone
by Aleid Ghadah Mohammad S., Fitri Khoerunnisa, Severinne Rigolet, T. Jean Daou, Tau-Chuan Ling and Eng-Poh Ng
Processes 2020, 8(1), 96; https://doi.org/10.3390/pr8010096 - 10 Jan 2020
Cited by 7 | Viewed by 3736
Abstract
Cs–pollucite can be a potential solid base catalyst due to the presence of (Si-O-Al)−Cs+ basic sites. However, it severely suffers from molecular diffusion and pore accessibility problems due to its small micropore opening. Herein, we report the use of new [...] Read more.
Cs–pollucite can be a potential solid base catalyst due to the presence of (Si-O-Al)−Cs+ basic sites. However, it severely suffers from molecular diffusion and pore accessibility problems due to its small micropore opening. Herein, we report the use of new organosilane, viz. dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC), as a promising pore-expanding agent to develop the hierarchical structure in nanosized Cs–pollucite. In respect to this, four different amounts of TPOAC were added during the synthesis of hierarchical Cs–pollucite (CP-x, x = 0, 0.3, 1.0, or 2.0, where x is the molar ratio of TPOAC) in order to investigate the effects of TPOAC in the crystallization process of Cs–pollucite. The results show that an addition of TPOAC altered the physico-chemical and morphological properties of hierarchical Cs–pollucite, such as the crystallinity, crystallite size, pore size distribution, surface areas, pore volume, and surface basicity. The prepared solids were also tested in Claisen–Schmidt condensation of benzaldehyde and acetophenone, where 82.2% of the conversion and 100% selectivity to chalcone were achieved by the CP-2.0 catalyst using non-microwave instant heating (200 °C, 100 min). The hierarchical CP-2.0 nanocatalyst also showed better catalytic performance than other homogenous and heterogeneous catalysts and displayed a high catalyst reusability with no significant deterioration in the catalytic performance even after five consecutive reaction runs. Full article
(This article belongs to the Special Issue Synthesis and Application of Novel Nanocatalysts)
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<p>TG curves of as-synthesized (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0.</p> Full article ">Figure 2
<p><sup>29</sup>Si MAS + DEC NMR spectra of as-synthesized (<b>a</b>) CP-0 and (<b>b</b>) CP-2.0.</p> Full article ">Figure 3
<p>XRD patterns of calcined (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0.</p> Full article ">Figure 4
<p>FESEM and particle size distributions (with standard deviation, S.D) of calcined (<b>a</b>–<b>c</b>) CP-0, (<b>d</b>–<b>f</b>) CP-0.3, (<b>g</b>–<b>i</b>) CP-1.0, and (<b>j</b>–<b>l</b>) CP-2.0.</p> Full article ">Figure 5
<p>IR spectra of calcined (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0.</p> Full article ">Figure 6
<p>Nitrogen gas adsorption (closed symbols) and desorption (open symbols) curves of (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0. Inset: Pore size distribution derived from the DFT method.</p> Full article ">Figure 7
<p>CO<sub>2</sub>-TPD of (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0.</p> Full article ">Figure 8
<p>Correlation plots between the amount of TPOAC added with the specific surface area (S<sub>BET</sub>) and basicity of Cs–pollicite samples.</p> Full article ">Figure 9
<p>(<b>A</b>) Claisen–Schmidt condensation of benzaldehyde and acetophenone catalyzed with (<b>a</b>) CP-0, (<b>b</b>) CP-0.3, (<b>c</b>) CP-1.0, and (<b>d</b>) CP-2.0 nanocatalysts at 200 °C, where the respective Arrhenius linear plots are also shown in (<b>B</b>) using the second-order rate constants determined at 180, 190, and 200 °C.</p> Full article ">Figure 10
<p>Effect of catalyst loading on the conversion of Claisen–Schmidt condensation of benzaldehyde and acetophenone. Catalyst = CP-2.0, reaction temperature = 200 °C, reaction time = 100 min, benzaldehyde = 10 mmol, acetophenone = 5 mmol, solvent free.</p> Full article ">Figure 11
<p>Effect of the acetophenone:benzaldehyde molar ratio on the conversion of Claisen–Schmidt condensation. Catalyst = CP-2.0, catalyst loading = 0.50 g, reaction temperature = 200 °C, reaction time = 100 min, solvent-free.</p> Full article ">Figure 12
<p>(<b>A</b>) Conversion of acetophenone in Claisen–Schmidt condensation reaction using different catalysts (reaction temperature = 200 °C, time = 100 min, benzaldehyde = 10 mmol, acetophenone = 5 mmol), (<b>B</b>) catalyst reusability test of CP-2.0 in Claisen–Schmidt condensation of benzaldehyde and acetophenone, and (<b>C</b>) XRD patterns of (<b>a</b>) fresh CP-2.0 and (<b>b</b>) CP-2.0 after five consecutive reaction runs.</p> Full article ">
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