Pub Date : 2023-10-09DOI: 10.3390/chemengineering7050094
Nadezhda Petkova, Ani Petrova, Ivan Ivanov, Ivanka Hambarlyiska, Yulian Tumbarski, Ivayla Dincheva, Manol Ognyanov, Petko Denev
This research aimed to reveal the chemical composition of different fractions obtained by sequential extraction of purple coneflower (Echinacea purpurea) roots and to evaluate the antimicrobial activity of some of them. Hexane, chloroform, ethyl acetate, and water were used as solvents to obtain the corresponding extracts. A GC-MS analysis was employed to reveal the chemical composition of hexane, chloroform, and ethyl acetate fractions. Conventional and ultrasound-assisted water extraction was performed to isolate inulin-type polysaccharides. Eighteen microorganisms were used for testing the antimicrobial activity of the obtained organic extracts. From GC-MS analysis more than forty compounds were detected in the fractions, including fatty acids, organic acids, fatty alcohols, sterols, and terpenes. Only in ethyl acetate extract were found mannitol and fructose isomers, while in chloroform extract were detected α- and β-amyrin, and betulin. Ethyl acetate fraction demonstrated the highest antimicrobial activity against 11 microorganisms (Bacillus cereus, B. amyloliquefaciens, Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, Saccharomices cerevisiae, and Peniclium sp.). The polysaccharide fractions were structurally characterized by FT-IR and NMR studies as linear inulin having β-(2→1)-linked Fru units and a T-Glc unit linked α-(1→2). Inulin from coneflower roots showed poor flowability, promising bulk and tapped density, swelling properties, and better oil-holding than water-holding capacity. This study demonstrated the potential of coneflower root fractions as a rich source of phytochemicals with antimicrobial activities and potential prebiotic activity due to inulin content (15% yield) and echinacea root as a useful biobased industrial crop/material.
{"title":"Chemical Composition of Different Extracts from Echinacea purpurea (L.) Moench Roots and Evaluation of Their Antimicrobial Activity","authors":"Nadezhda Petkova, Ani Petrova, Ivan Ivanov, Ivanka Hambarlyiska, Yulian Tumbarski, Ivayla Dincheva, Manol Ognyanov, Petko Denev","doi":"10.3390/chemengineering7050094","DOIUrl":"https://doi.org/10.3390/chemengineering7050094","url":null,"abstract":"This research aimed to reveal the chemical composition of different fractions obtained by sequential extraction of purple coneflower (Echinacea purpurea) roots and to evaluate the antimicrobial activity of some of them. Hexane, chloroform, ethyl acetate, and water were used as solvents to obtain the corresponding extracts. A GC-MS analysis was employed to reveal the chemical composition of hexane, chloroform, and ethyl acetate fractions. Conventional and ultrasound-assisted water extraction was performed to isolate inulin-type polysaccharides. Eighteen microorganisms were used for testing the antimicrobial activity of the obtained organic extracts. From GC-MS analysis more than forty compounds were detected in the fractions, including fatty acids, organic acids, fatty alcohols, sterols, and terpenes. Only in ethyl acetate extract were found mannitol and fructose isomers, while in chloroform extract were detected α- and β-amyrin, and betulin. Ethyl acetate fraction demonstrated the highest antimicrobial activity against 11 microorganisms (Bacillus cereus, B. amyloliquefaciens, Staphylococcus aureus, Listeria monocytogenes, Salmonella enteritis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, Saccharomices cerevisiae, and Peniclium sp.). The polysaccharide fractions were structurally characterized by FT-IR and NMR studies as linear inulin having β-(2→1)-linked Fru units and a T-Glc unit linked α-(1→2). Inulin from coneflower roots showed poor flowability, promising bulk and tapped density, swelling properties, and better oil-holding than water-holding capacity. This study demonstrated the potential of coneflower root fractions as a rich source of phytochemicals with antimicrobial activities and potential prebiotic activity due to inulin content (15% yield) and echinacea root as a useful biobased industrial crop/material.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135142213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-07DOI: 10.3390/chemengineering7050093
Andrey Altynov, Ilya Bogdanov, Daniil Lukyanov, Maria Kirgina
Natural gas liquids are a by-product of natural gas preparation, one of the most common and environmentally friendly energy sources. In natural gas fields located in remote areas, there is no resource-efficient way to use natural gas liquids. However, natural gas liquids are a valuable hydrocarbon feedstock for the production of motor fuels, in particular motor gasolines. The aim of this work is to develop a method for obtaining motor gasolines by processing natural gas liquids on a zeolite catalyst, taking into account the influence of the particle size of the zeolite catalyst, the technological parameters of the process, and the composition of the feedstock. As part of the work, for the first time, regularities of the influence of zeolite catalyst particle size, technological parameters of the process and the composition of feedstock on the composition and characteristics of the resulting processed products were revealed. A database about the composition and characteristics of natural gas liquids, obtained from various gas fields in Western Siberia of the Russian Federation, has been accumulated. During the study, it was found that the optimal particle size of the zeolite catalyst is 0.50–1.00 mm; optimal technological parameters are a temperature of 375 °C, pressure 2.5 atm. and the feedstock space velocity 2 h−1. It is shown that the processing of natural gas liquids of various compositions on a zeolite catalyst, on average, makes it possible to increase their detonation resistance by more than 16 points. The results obtained indicate the prospects of using the process for the production of motor gasoline. The paper presents a number of blending recipes for obtaining fuels, both within the framework of production at the fields and at processing plants.
{"title":"Natural Gas Liquids into Motor Gasolines: Methodology for Processing on a Zeolite Catalyst and Development of Blending Recipes","authors":"Andrey Altynov, Ilya Bogdanov, Daniil Lukyanov, Maria Kirgina","doi":"10.3390/chemengineering7050093","DOIUrl":"https://doi.org/10.3390/chemengineering7050093","url":null,"abstract":"Natural gas liquids are a by-product of natural gas preparation, one of the most common and environmentally friendly energy sources. In natural gas fields located in remote areas, there is no resource-efficient way to use natural gas liquids. However, natural gas liquids are a valuable hydrocarbon feedstock for the production of motor fuels, in particular motor gasolines. The aim of this work is to develop a method for obtaining motor gasolines by processing natural gas liquids on a zeolite catalyst, taking into account the influence of the particle size of the zeolite catalyst, the technological parameters of the process, and the composition of the feedstock. As part of the work, for the first time, regularities of the influence of zeolite catalyst particle size, technological parameters of the process and the composition of feedstock on the composition and characteristics of the resulting processed products were revealed. A database about the composition and characteristics of natural gas liquids, obtained from various gas fields in Western Siberia of the Russian Federation, has been accumulated. During the study, it was found that the optimal particle size of the zeolite catalyst is 0.50–1.00 mm; optimal technological parameters are a temperature of 375 °C, pressure 2.5 atm. and the feedstock space velocity 2 h−1. It is shown that the processing of natural gas liquids of various compositions on a zeolite catalyst, on average, makes it possible to increase their detonation resistance by more than 16 points. The results obtained indicate the prospects of using the process for the production of motor gasoline. The paper presents a number of blending recipes for obtaining fuels, both within the framework of production at the fields and at processing plants.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135300763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present research involves producing graphene oxide (GO) using the Hummers method, generating a composite using GO and PVA, and analyzing these composites’ structural and optical characteristics. PVA and GO were used in varied percentages to deal with the issue of how the features of GO/PVA alter depending on concentration. The impact of thermal annealing on the structure and optical characteristics of GO/PVA materials at various concentrations were also investigated. UV-VIS was used to investigate the band gap value of GO/PVA composites. The band gap value changed due to an increase in the concentration of GO in the composites in the PVA and the impact of thermal annealing. The band gap value, specific resistance, and dielectric constant were all found to be well controlled by varying the thermal annealing temperature and the concentration of GO in this case. Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) were performed on pure PVA and GO/PVA samples in various percentages of GO in order to examine the effect of temperature on the physical properties of (n = 1, 2, 3, 5, 20%) nGO%/PVA nanocomposites. Thermal stability increased as the fraction of GO in the PVA polymer matrix increased.
{"title":"Investigating the Effect of Thermal Annealing and Changing the Concentration of GO in GO/PVA Nanocomposites on Their Structural, Electrical, and Optical Properties","authors":"Lala Gahramanli, Mustafa Muradov, Goncha Eyvazova, Mahammad Baghir Baghirov, Sevinj Mammadyarova, Gunel Aliyeva, Elman Hajiyev, Faig Mammadov, Stefano Bellucci","doi":"10.3390/chemengineering7050092","DOIUrl":"https://doi.org/10.3390/chemengineering7050092","url":null,"abstract":"The present research involves producing graphene oxide (GO) using the Hummers method, generating a composite using GO and PVA, and analyzing these composites’ structural and optical characteristics. PVA and GO were used in varied percentages to deal with the issue of how the features of GO/PVA alter depending on concentration. The impact of thermal annealing on the structure and optical characteristics of GO/PVA materials at various concentrations were also investigated. UV-VIS was used to investigate the band gap value of GO/PVA composites. The band gap value changed due to an increase in the concentration of GO in the composites in the PVA and the impact of thermal annealing. The band gap value, specific resistance, and dielectric constant were all found to be well controlled by varying the thermal annealing temperature and the concentration of GO in this case. Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) were performed on pure PVA and GO/PVA samples in various percentages of GO in order to examine the effect of temperature on the physical properties of (n = 1, 2, 3, 5, 20%) nGO%/PVA nanocomposites. Thermal stability increased as the fraction of GO in the PVA polymer matrix increased.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135644886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.3390/chemengineering7050091
Miguel Castilla-Barbosa, Orlando Rincón-Arango, Manuel Ocampo-Terreros
The zeta potential of soils is an electric potential in the double-layer interface and is a physical property exhibited by any particle related to electrochemical attractive forces. On the other hand, the chemical aging phenomenon is seen as the chief mechanism of the aging of sands due to the dissolution and precipitation of minerals, resulting in the development of the cementation of particles in granular mediums. The present investigation focuses on determining whether granular materials can generate cementation due to electrokinetic forces, and if the zeta potential could be related as a measure of the potential of chemical aging. X-ray fluorescence and diffraction tests were performed to characterize four representative fractions of one kind of sand, and zeta potential studies were carried out to determine the electrical potential on the mineral surfaces of each one. Zeta potential analysis showed both dependence on the mineralogical content and the variation in the pH of the colloidal solution fluid because the increase in OH- ion concentrations increases the thickness of the diffuse double layer and the electrokinetic forces of attraction. Moreover, the zeta potential showed an increase in the thickness of the diffuse double layer, due to the electrokinetic forces, which can be associated with the development of cohesive forces with a dependence on the mineralogy of sands.
{"title":"Electrokinetic Forces as an Electrical Measure of Chemical Aging Potential in Granular Materials","authors":"Miguel Castilla-Barbosa, Orlando Rincón-Arango, Manuel Ocampo-Terreros","doi":"10.3390/chemengineering7050091","DOIUrl":"https://doi.org/10.3390/chemengineering7050091","url":null,"abstract":"The zeta potential of soils is an electric potential in the double-layer interface and is a physical property exhibited by any particle related to electrochemical attractive forces. On the other hand, the chemical aging phenomenon is seen as the chief mechanism of the aging of sands due to the dissolution and precipitation of minerals, resulting in the development of the cementation of particles in granular mediums. The present investigation focuses on determining whether granular materials can generate cementation due to electrokinetic forces, and if the zeta potential could be related as a measure of the potential of chemical aging. X-ray fluorescence and diffraction tests were performed to characterize four representative fractions of one kind of sand, and zeta potential studies were carried out to determine the electrical potential on the mineral surfaces of each one. Zeta potential analysis showed both dependence on the mineralogical content and the variation in the pH of the colloidal solution fluid because the increase in OH- ion concentrations increases the thickness of the diffuse double layer and the electrokinetic forces of attraction. Moreover, the zeta potential showed an increase in the thickness of the diffuse double layer, due to the electrokinetic forces, which can be associated with the development of cohesive forces with a dependence on the mineralogy of sands.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135457896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-28DOI: 10.3390/chemengineering7050090
Néstor A. Urbina-Suarez, Cristian J. Salcedo-Pabón, Jefferson E. Contreras-Ropero, German L. López-Barrera, Janet B. García-Martínez, Andrés F. Barajas-Solano, Fiderman Machuca-Martínez
This study investigates the influence of photoperiod and wastewater concentration on the growth of microalgae and cyanobacteria for the removal of environmentally significant parameters (COD, BOD, Cr, Fe, color, chlorides, nitrogen compounds, and phosphates) from dyeing wastewater. A two-factor central composite design with surface response was employed, involving two algae species (Chlorella and Scenedesmus sp.) and two cyanobacteria species (Hapalosiphon and Oscillatoria sp.). The findings indicated that extended photoperiods (>13 h) and higher wastewater concentrations (70–80% v/v) enhanced biomass production across all strains. However, Hapalosiphon and Chlorella sp. (1.6 and 0.45 g/L) exhibited better tolerance to the wastewater’s high toxicity, resulting in higher biomass concentrations and improved COD and BOD removal by Hapalosiphon sp. (75% and 80%, respectively). Further analysis of the obtained biomass revealed their potential applications. Among the cyanobacteria, Hapalosiphon sp. synthesized the highest concentrations of total proteins and lipids (38% and 28% w/w, respectively), while Oscillatoria sp. displayed a high protein content (42% w/w). In contrast, the algae demonstrated a strong propensity for storing substantial quantities of total carbohydrates (65% and 57% w/w for Scenedesmus and Chlorella sp., respectively). These results signify the feasibility of cultivating photosynthetic microorganisms in industrial dyeing wastewater as a sustainable source of nutrients for targeted metabolite production.
{"title":"A Phytochemical Approach to the Removal of Contaminants from Industrial Dyeing Wastewater","authors":"Néstor A. Urbina-Suarez, Cristian J. Salcedo-Pabón, Jefferson E. Contreras-Ropero, German L. López-Barrera, Janet B. García-Martínez, Andrés F. Barajas-Solano, Fiderman Machuca-Martínez","doi":"10.3390/chemengineering7050090","DOIUrl":"https://doi.org/10.3390/chemengineering7050090","url":null,"abstract":"This study investigates the influence of photoperiod and wastewater concentration on the growth of microalgae and cyanobacteria for the removal of environmentally significant parameters (COD, BOD, Cr, Fe, color, chlorides, nitrogen compounds, and phosphates) from dyeing wastewater. A two-factor central composite design with surface response was employed, involving two algae species (Chlorella and Scenedesmus sp.) and two cyanobacteria species (Hapalosiphon and Oscillatoria sp.). The findings indicated that extended photoperiods (>13 h) and higher wastewater concentrations (70–80% v/v) enhanced biomass production across all strains. However, Hapalosiphon and Chlorella sp. (1.6 and 0.45 g/L) exhibited better tolerance to the wastewater’s high toxicity, resulting in higher biomass concentrations and improved COD and BOD removal by Hapalosiphon sp. (75% and 80%, respectively). Further analysis of the obtained biomass revealed their potential applications. Among the cyanobacteria, Hapalosiphon sp. synthesized the highest concentrations of total proteins and lipids (38% and 28% w/w, respectively), while Oscillatoria sp. displayed a high protein content (42% w/w). In contrast, the algae demonstrated a strong propensity for storing substantial quantities of total carbohydrates (65% and 57% w/w for Scenedesmus and Chlorella sp., respectively). These results signify the feasibility of cultivating photosynthetic microorganisms in industrial dyeing wastewater as a sustainable source of nutrients for targeted metabolite production.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135388649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-19DOI: 10.3390/chemengineering7050089
G. Zh. Moldabayeva, G. M. Efendiyev, A. L. Kozlovskiy, N. S. Buktukov, S. V. Abbasova
This article is devoted to the construction and statistical analysis of models that express the relationship between performance indicators and a large number of geological and technological factors. The volume of additionally produced oil, the volume of limited water, the duration of the effect and profit per well, taking into account the cost of the polymer, are taken as performance indicators. The key goal of the article is to develop a method and models for making technological choices to enhance the effectiveness of measures to limit water inflows in production wells under conditions of uncertainty. The methodological basis of the study was the provisions and principles of mathematical statistics, the theory of fuzzy sets, the theory of decision-making under conditions of uncertainty based on materials generated by statistical processing of data on physical and geological conditions, and the results of waterproofing work, obtaining, and analyzing information. The scientific novelty of the study lies in the construction of technological solutions based on modeling the performance indicators of waterproofing works with an assessment of the significance of each factor and the reliability of the models and decision-making under conditions of uncertainty, expressed by multi-criteria and multi-factoriality. The practical significance follows from a solution that satisfies the conditions for achieving the maximum of all indicators of the efficiency of the process of limiting water inflows, both technological and economic. An algorithm was developed and implemented for evaluating optimal technological solutions according to four criteria based on information about the geological and physical conditions of the field and the experience of implementing geological and technical measures to limit water inflows, including the analysis of factors, their weighted contribution, model building, statistical evaluation of reliability indicators, decision-making taking into account uncertainty.
{"title":"Modeling and Adoption of Technological Solutions in Order to Enhance the Effectiveness of Measures to Limit Water Inflows into Oil Wells under Conditions of Uncertainty","authors":"G. Zh. Moldabayeva, G. M. Efendiyev, A. L. Kozlovskiy, N. S. Buktukov, S. V. Abbasova","doi":"10.3390/chemengineering7050089","DOIUrl":"https://doi.org/10.3390/chemengineering7050089","url":null,"abstract":"This article is devoted to the construction and statistical analysis of models that express the relationship between performance indicators and a large number of geological and technological factors. The volume of additionally produced oil, the volume of limited water, the duration of the effect and profit per well, taking into account the cost of the polymer, are taken as performance indicators. The key goal of the article is to develop a method and models for making technological choices to enhance the effectiveness of measures to limit water inflows in production wells under conditions of uncertainty. The methodological basis of the study was the provisions and principles of mathematical statistics, the theory of fuzzy sets, the theory of decision-making under conditions of uncertainty based on materials generated by statistical processing of data on physical and geological conditions, and the results of waterproofing work, obtaining, and analyzing information. The scientific novelty of the study lies in the construction of technological solutions based on modeling the performance indicators of waterproofing works with an assessment of the significance of each factor and the reliability of the models and decision-making under conditions of uncertainty, expressed by multi-criteria and multi-factoriality. The practical significance follows from a solution that satisfies the conditions for achieving the maximum of all indicators of the efficiency of the process of limiting water inflows, both technological and economic. An algorithm was developed and implemented for evaluating optimal technological solutions according to four criteria based on information about the geological and physical conditions of the field and the experience of implementing geological and technical measures to limit water inflows, including the analysis of factors, their weighted contribution, model building, statistical evaluation of reliability indicators, decision-making taking into account uncertainty.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135063233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-18DOI: 10.3390/chemengineering7050088
Pathik Sahoo
Multistep flow catalytic reactions in organic chemistry integrate multiple sequential organic reactions to enhance cost-efficiency, time management, and labour resources, all while boosting effectiveness and environmental sustainability. Similar to how we select molecular synthons for reactions in retrosynthesis, we can employ time-crystal synthons to integrate catalytic reaction cycles in the development of a reaction pathway. This involves considering individual catalytic reaction steps of cycles as time-consuming events that can be topologically arranged like a clock. This results in a perpetual machine that violates time translational symmetry, leading to the production of a time crystal. This approach involves transferring a single product from one catalytic cycle to a neighbouring reaction cycle, connecting various reaction vessels vertically to establish a ‘cascade’ of reaction cycles. Additionally, catalytic cycles can be integrated by sharing common reaction steps or implementing a metathesis reaction at the junction zone of two neighbouring cycles. Here, the concept of time-crystal synthons facilitates the linear integration of heterogeneous catalytic cycles, step by step, to transfer products through the common reaction medium when modifying conventional flow synthesis. Significantly, this time-crystal synthon-driven multistep approach offers advantages over conventional flow synthesis, as the reaction vessels can be equipped with microwave and photosynthesis methodologies, allowing for the collection of specific products from their respective vessels as needed, providing more options to integrate reactions and enabling flow control using gravity.
{"title":"Time Crystal Synthon: The Way to Integrate Cascade Reactions for Advancing Multistep Flow Synthesis","authors":"Pathik Sahoo","doi":"10.3390/chemengineering7050088","DOIUrl":"https://doi.org/10.3390/chemengineering7050088","url":null,"abstract":"Multistep flow catalytic reactions in organic chemistry integrate multiple sequential organic reactions to enhance cost-efficiency, time management, and labour resources, all while boosting effectiveness and environmental sustainability. Similar to how we select molecular synthons for reactions in retrosynthesis, we can employ time-crystal synthons to integrate catalytic reaction cycles in the development of a reaction pathway. This involves considering individual catalytic reaction steps of cycles as time-consuming events that can be topologically arranged like a clock. This results in a perpetual machine that violates time translational symmetry, leading to the production of a time crystal. This approach involves transferring a single product from one catalytic cycle to a neighbouring reaction cycle, connecting various reaction vessels vertically to establish a ‘cascade’ of reaction cycles. Additionally, catalytic cycles can be integrated by sharing common reaction steps or implementing a metathesis reaction at the junction zone of two neighbouring cycles. Here, the concept of time-crystal synthons facilitates the linear integration of heterogeneous catalytic cycles, step by step, to transfer products through the common reaction medium when modifying conventional flow synthesis. Significantly, this time-crystal synthon-driven multistep approach offers advantages over conventional flow synthesis, as the reaction vessels can be equipped with microwave and photosynthesis methodologies, allowing for the collection of specific products from their respective vessels as needed, providing more options to integrate reactions and enabling flow control using gravity.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135155109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-15DOI: 10.3390/chemengineering7050087
Borhan Albiss, Mohammad Al-Widyan
This study presents the numerical simulation, optimization, preparation, and characterization of Cu(In, Ga)Se2 (CIGS) thin-film solar cells (TFSCs). Different cell parameters were investigated, including Ga/(Ga+In) (GGI) ratios, the thicknesses of CIGS absorption layers, the fill factor (FF), the open-circuit voltage (Voc), and the short-circuit current (Isc). The effects of the simulated parameters on the power conversion efficiency (η) of each prototype CIGS cells were investigated. The optimal GGI ratio was approximately 0.6. Using COMSOL Multiphysics software, a CIGS layer thickness of 2 μm and an η of 17% was calculated, assuming constant operating temperatures. Moreover, prototype CIGS solar cells with various compositions were prepared via a simple and cost-effective method based on sol–gel, sonication, and spin-coating techniques. The microstructures and electrical and optical properties of the CIGS-based solar cells were evaluated using current–voltage (I-V) characteristics, scanning electron microscopy (SEM), X-ray diffraction, atomic force microscopy (AFM), and UV-vis spectroscopy. The elemental compositions of the solar cell layers were evaluated via energy-dispersive X-ray fluorescence (EDXRF). The obtained results were compared with the experimental results. For example, in a prototype cell with a CIGS absorption layer thickness of 2 μm and a GGI ratio of 0.6, the experimental value of η was about 15%. Our results revealed that the agreement between the simulation results and the experimental findings for most of the simulated parameters is quite good. These findings indicate that a non-destructive analysis based on EDXRF is a versatile tool for evaluating CIGS solar cells in a very short time with excellent repeatability for both layer composition and thickness.
{"title":"Numerical Simulation, Preparation, and Evaluation of Cu(In, Ga)Se2 (CIGS) Thin-Film Solar Cells","authors":"Borhan Albiss, Mohammad Al-Widyan","doi":"10.3390/chemengineering7050087","DOIUrl":"https://doi.org/10.3390/chemengineering7050087","url":null,"abstract":"This study presents the numerical simulation, optimization, preparation, and characterization of Cu(In, Ga)Se2 (CIGS) thin-film solar cells (TFSCs). Different cell parameters were investigated, including Ga/(Ga+In) (GGI) ratios, the thicknesses of CIGS absorption layers, the fill factor (FF), the open-circuit voltage (Voc), and the short-circuit current (Isc). The effects of the simulated parameters on the power conversion efficiency (η) of each prototype CIGS cells were investigated. The optimal GGI ratio was approximately 0.6. Using COMSOL Multiphysics software, a CIGS layer thickness of 2 μm and an η of 17% was calculated, assuming constant operating temperatures. Moreover, prototype CIGS solar cells with various compositions were prepared via a simple and cost-effective method based on sol–gel, sonication, and spin-coating techniques. The microstructures and electrical and optical properties of the CIGS-based solar cells were evaluated using current–voltage (I-V) characteristics, scanning electron microscopy (SEM), X-ray diffraction, atomic force microscopy (AFM), and UV-vis spectroscopy. The elemental compositions of the solar cell layers were evaluated via energy-dispersive X-ray fluorescence (EDXRF). The obtained results were compared with the experimental results. For example, in a prototype cell with a CIGS absorption layer thickness of 2 μm and a GGI ratio of 0.6, the experimental value of η was about 15%. Our results revealed that the agreement between the simulation results and the experimental findings for most of the simulated parameters is quite good. These findings indicate that a non-destructive analysis based on EDXRF is a versatile tool for evaluating CIGS solar cells in a very short time with excellent repeatability for both layer composition and thickness.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135435297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-14DOI: 10.3390/chemengineering7050086
Karla Y. Mora-Bonilla, Iván F. Macías-Quiroga, Nancy R. Sanabria-González, María T. Dávila-Arias
The present study investigated the degradation of an aqueous Allura Red AC (AR–AC) solution by activating hydrogen peroxide with bicarbonate using cobalt ion (Co2+) as the catalyst. Four independent variables (H2O2, NaHCO3, Co2+, and dye concentrations) were analyzed in the composite central design (CCD). AR–AC degradation was optimized using the response surface methodology (RSM). Under optimal degradation conditions (41.86 mg/L AR–AC, 5.58 mM H2O2, 2.00 mM NaHCO3, and 9.00 µM Co2+), decolorization > 99.86%, mineralization (CO2 to conversion) of 12.99%, and total nitrogen removal of 51.97% were achieved. The predicted values for the three response variables were consistent with the experimental values, with determination coefficients (R2) greater than 0.9053. Because cobalt ions (Co2+) are a source of water pollution, after oxidation, these were adsorbed on sodium bentonite (Na–Bent), obtaining a final concentration of <0.01 mg/L. Bicarbonate-activated hydrogen peroxide is a potential technology for dye wastewater treatment that operates at an alkaline pH and at ambient temperature.
本研究以钴离子(Co2+)为催化剂，用碳酸氢盐活化过氧化氢，研究了水溶液中紫外光AC (AR-AC)的降解。在复合中心设计(CCD)中分析了四个自变量(H2O2, NaHCO3, Co2+和染料浓度)。采用响应面法(RSM)对AR-AC降解进行了优化。在最佳降解条件(41.86 mg/L AR-AC, 5.58 mM H2O2, 2.00 mM NaHCO3, 9.00µM Co2+)下，脱色>矿化率(CO2转化率)为12.99%，总氮去除率为51.97%。3个响应变量的预测值与实验值一致，决定系数(R2)均大于0.9053。由于钴离子(Co2+)是水体的污染源，经氧化后吸附在钠基膨润土(Na-Bent)上，最终浓度为0.01 mg/L。碳酸氢盐活化过氧化氢是一种有潜力的染料废水处理技术，在碱性pH值和环境温度下运行。
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Pub Date : 2023-09-14DOI: 10.3390/chemengineering7050085
Laith S. Sabri, Abbas J. Sultan, Jamal M. Ali, Hasan Shakir Majdi, Muthanna H. Al-Dahhan
Fluidized bed reactors are essential in a wide range of industrial applications, encompassing processes such as Fischer–Tropsch synthesis and catalytic cracking. The optimization of performance and reduction in energy consumption in these reactors necessitate the use of efficient heat transfer mechanisms. The present work examines the considerable impact of tube end geometries, superficial gas velocity, and radial position on heat transfer coefficients within fluidized bed reactors. It was found that the tapered tube end configurations have been empirically proven to improve energy efficiency in fluidized bed reactors significantly. For example, at a superficial gas velocity of 0.4 m/s, the tapered end form’s local heat transfer coefficient (LHTC) demonstrated a significant 20% enhancement compared to the flat end shape. The results and findings of this work make a valuable contribution to the advancement of complex models, enhance the efficiency of fluidized bed reactor processes, and encourage further investigation into novel tube geometries.
{"title":"Enhancing Heat Transfer Performance in Simulated Fischer–Tropsch Fluidized Bed Reactor through Tubes Ends Modifications","authors":"Laith S. Sabri, Abbas J. Sultan, Jamal M. Ali, Hasan Shakir Majdi, Muthanna H. Al-Dahhan","doi":"10.3390/chemengineering7050085","DOIUrl":"https://doi.org/10.3390/chemengineering7050085","url":null,"abstract":"Fluidized bed reactors are essential in a wide range of industrial applications, encompassing processes such as Fischer–Tropsch synthesis and catalytic cracking. The optimization of performance and reduction in energy consumption in these reactors necessitate the use of efficient heat transfer mechanisms. The present work examines the considerable impact of tube end geometries, superficial gas velocity, and radial position on heat transfer coefficients within fluidized bed reactors. It was found that the tapered tube end configurations have been empirically proven to improve energy efficiency in fluidized bed reactors significantly. For example, at a superficial gas velocity of 0.4 m/s, the tapered end form’s local heat transfer coefficient (LHTC) demonstrated a significant 20% enhancement compared to the flat end shape. The results and findings of this work make a valuable contribution to the advancement of complex models, enhance the efficiency of fluidized bed reactor processes, and encourage further investigation into novel tube geometries.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134912911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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