Pub Date : 2023-08-17DOI: 10.3390/chemengineering7040074
Ismaila A. Oyehan, A. Osunleke, Olanrewaju O. Ajani
The dynamics of a quadruple tank system (QTS) represent an extensive class of multivariate nonlinear uncertain systems found in the industry. It has been established that changes in split fractions affect the transmission zero location, thereby altering the operating conditions between the minimum and non-minimum phase regions. The latter is difficult to control as more fluid flows into the two upper tanks than into the two bottom tanks, resulting in competing effects between the initial and final system responses. This attribute, alongside nonlinearity, uncertainties, constraints, and a multivariate nature, can degrade closed-loop system performance, leading to instability. In this study, we addressed the aforementioned challenges by designing controllers for the regulation of the water flow in the two bottom tanks of the QTS. For comparative analysis, three controller algorithms—a nonlinear model predictive controller (NMPC), NMPC augmented with an extended Kalman filter (i.e., NMPC-EKF) and linear model predictive controller (LMPC)—were considered in the analysis and design of the control mechanism for the quadruple water level system in a non-minimum phase condition via the Matrix Laboratory (MATLAB) simulation package environment. The simulated and real-time results in the closed loop were analyzed, and the controller performances were considered based on faster setpoint responses, less oscillation, settling time, overshoot, and smaller integral absolute error (IAE) and integral square error (ISE) under various operational conditions. The study showed that the NMPC, when augmented with an EKF, is effective for the control of a QTS in the non-minimum phase and could be designed for more complex, nonlinear, and multivariable dynamics systems, even in the presence of constraints.
{"title":"Closed-Loop Stability of a Non-Minimum Phase Quadruple Tank System Using a Nonlinear Model Predictive Controller with EKF","authors":"Ismaila A. Oyehan, A. Osunleke, Olanrewaju O. Ajani","doi":"10.3390/chemengineering7040074","DOIUrl":"https://doi.org/10.3390/chemengineering7040074","url":null,"abstract":"The dynamics of a quadruple tank system (QTS) represent an extensive class of multivariate nonlinear uncertain systems found in the industry. It has been established that changes in split fractions affect the transmission zero location, thereby altering the operating conditions between the minimum and non-minimum phase regions. The latter is difficult to control as more fluid flows into the two upper tanks than into the two bottom tanks, resulting in competing effects between the initial and final system responses. This attribute, alongside nonlinearity, uncertainties, constraints, and a multivariate nature, can degrade closed-loop system performance, leading to instability. In this study, we addressed the aforementioned challenges by designing controllers for the regulation of the water flow in the two bottom tanks of the QTS. For comparative analysis, three controller algorithms—a nonlinear model predictive controller (NMPC), NMPC augmented with an extended Kalman filter (i.e., NMPC-EKF) and linear model predictive controller (LMPC)—were considered in the analysis and design of the control mechanism for the quadruple water level system in a non-minimum phase condition via the Matrix Laboratory (MATLAB) simulation package environment. The simulated and real-time results in the closed loop were analyzed, and the controller performances were considered based on faster setpoint responses, less oscillation, settling time, overshoot, and smaller integral absolute error (IAE) and integral square error (ISE) under various operational conditions. The study showed that the NMPC, when augmented with an EKF, is effective for the control of a QTS in the non-minimum phase and could be designed for more complex, nonlinear, and multivariable dynamics systems, even in the presence of constraints.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44969194","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 : 2023-08-17DOI: 10.3390/chemengineering7040073
Lucas B. de Faria, G. F. Teixeira, A. C. F. Alves, J. Linares, S. Oliveira, A. Motheo, F. Colmati
This work presents the electrochemical degradation of the herbicide Diuron by anodic oxidation on a Ti/Ru0.3Ti0.7O2 metal mixed oxide anode using sulfate as the electrolyte. The study includes the influence of Diuron concentration and current density on anodic oxidation. The results evidence a first-order degradation, with the highest capacity achieved at 40 mA cm−2 and at an initial Diuron concentration of 38 mg L−1. Nevertheless, in terms of efficiency and energy demand, the operation at 10 mA cm−2 is favored due to the more efficient and less energy-consuming condition. To discern the optimum design and operation conditions, this work presents the results of a preliminary technical–economic analysis, demonstrating that, to minimize the total costs of the system, it is recommended to seek the most efficient conditions, i.e., the conditions demanding the lowest applied charges with the highest Diuron degradation. At the same time, attention must be given to the required cell voltage to not increase excessively the operating costs.
本文研究了以硫酸盐为电解液，在Ti/Ru0.3Ti0.7O2金属混合氧化物阳极上阳极氧化降解除草剂迪乌隆。研究了Diuron浓度和电流密度对阳极氧化的影响。结果证明了一级降解，在40 mA cm−2和38 mg L−1的初始Diuron浓度下达到最高容量。然而，在效率和能源需求方面，由于效率更高，能耗更低，10毫安cm−2的操作更受青睐。为了确定最佳的设计和运行条件，本工作提出了初步的技术经济分析结果，表明为了使系统的总成本最小化，建议寻求最有效的条件，即要求最低的施加费用和最高的Diuron降解的条件。同时，必须注意所需的电池电压，以免过度增加运行成本。
{"title":"Electrochemical Degradation of Diuron by Anodic Oxidation on a Commercial Ru0.3Ti0.7O2 Anode in a Sulfate Medium","authors":"Lucas B. de Faria, G. F. Teixeira, A. C. F. Alves, J. Linares, S. Oliveira, A. Motheo, F. Colmati","doi":"10.3390/chemengineering7040073","DOIUrl":"https://doi.org/10.3390/chemengineering7040073","url":null,"abstract":"This work presents the electrochemical degradation of the herbicide Diuron by anodic oxidation on a Ti/Ru0.3Ti0.7O2 metal mixed oxide anode using sulfate as the electrolyte. The study includes the influence of Diuron concentration and current density on anodic oxidation. The results evidence a first-order degradation, with the highest capacity achieved at 40 mA cm−2 and at an initial Diuron concentration of 38 mg L−1. Nevertheless, in terms of efficiency and energy demand, the operation at 10 mA cm−2 is favored due to the more efficient and less energy-consuming condition. To discern the optimum design and operation conditions, this work presents the results of a preliminary technical–economic analysis, demonstrating that, to minimize the total costs of the system, it is recommended to seek the most efficient conditions, i.e., the conditions demanding the lowest applied charges with the highest Diuron degradation. At the same time, attention must be given to the required cell voltage to not increase excessively the operating costs.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45352142","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 : 2023-08-12DOI: 10.3390/chemengineering7040072
G. Smyrnakis, G. Stamoulis, D. Palaiogiannis, Theodoros G. Chatzimitakos, V. Athanasiadis, S. Lalas, D. Makris
The examination presented herein sought to establish a novel methodology for the efficient recovery of polyphenolic antioxidants from coffee processing residues, namely coffee silverskin (CSS). The process developed was an ethanol-based organosolv treatment, assisted by acid catalysis, using sulfuric acid or oxalic acid as the catalyst. The first approach was modeling treatment based on severity, where it was found that treatment dependence on time and temperature may well be described by linear relationships. Response surface methodology was then deployed as a consecutive stage, to optimize treatments with regard to catalyst concentration and resident time. In this case, again, linear models could effectively predict polyphenol recovery yield (YTP). For the sulfuric-acid-catalyzed treatment, the maximum theoretic YTP was found to be 10.95 ± 0.44 mg caffeic acid equivalent (CAE) g−1 DM, achieved at CSuAc = 1.5% and t = 300 min. On the other hand, the maximum YTP of 10.30 ± 0.53 could be attained at COxAc = 4%, and t = 300 min. Considering treatment severity, it was concluded that the use of oxalic acid, a food-grade organic acid, instead of sulfuric acid, a corrosive acid, would afford equivalent effects at lower severity. The high-performance liquid chromatography analyses also revealed that the extract produced through the oxalic-acid-catalyzed treatment was more enriched in neochlorogenic and chlorogenic acids, and it exhibited stronger antiradical activity, but weaker ferric-reducing effects. It is proposed that the methodology developed may contribute towards the use of coffee processing wastes as potential sources of bioactive ingredients and the design of novel functional products, in the frame of a more sustainable strategy for coffee processing companies.
{"title":"Recovery of Polyphenolic Antioxidants from Coffee Silverskin Using Acid-Catalyzed Ethanol Organosolv Treatment","authors":"G. Smyrnakis, G. Stamoulis, D. Palaiogiannis, Theodoros G. Chatzimitakos, V. Athanasiadis, S. Lalas, D. Makris","doi":"10.3390/chemengineering7040072","DOIUrl":"https://doi.org/10.3390/chemengineering7040072","url":null,"abstract":"The examination presented herein sought to establish a novel methodology for the efficient recovery of polyphenolic antioxidants from coffee processing residues, namely coffee silverskin (CSS). The process developed was an ethanol-based organosolv treatment, assisted by acid catalysis, using sulfuric acid or oxalic acid as the catalyst. The first approach was modeling treatment based on severity, where it was found that treatment dependence on time and temperature may well be described by linear relationships. Response surface methodology was then deployed as a consecutive stage, to optimize treatments with regard to catalyst concentration and resident time. In this case, again, linear models could effectively predict polyphenol recovery yield (YTP). For the sulfuric-acid-catalyzed treatment, the maximum theoretic YTP was found to be 10.95 ± 0.44 mg caffeic acid equivalent (CAE) g−1 DM, achieved at CSuAc = 1.5% and t = 300 min. On the other hand, the maximum YTP of 10.30 ± 0.53 could be attained at COxAc = 4%, and t = 300 min. Considering treatment severity, it was concluded that the use of oxalic acid, a food-grade organic acid, instead of sulfuric acid, a corrosive acid, would afford equivalent effects at lower severity. The high-performance liquid chromatography analyses also revealed that the extract produced through the oxalic-acid-catalyzed treatment was more enriched in neochlorogenic and chlorogenic acids, and it exhibited stronger antiradical activity, but weaker ferric-reducing effects. It is proposed that the methodology developed may contribute towards the use of coffee processing wastes as potential sources of bioactive ingredients and the design of novel functional products, in the frame of a more sustainable strategy for coffee processing companies.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46542048","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 : 2023-07-29DOI: 10.3390/chemengineering7040071
A. Zhuzhgov, L. Isupova, E. A. Suprun, A. Gorkusha
This study revealed an increased reactivity of centrifugally thermoactivated products of gibbsite toward aqueous solutions of nickel nitrate at room temperature as well as under hydrothermal conditions. X-ray, thermal, microscopy, adsorption and chemical analysis methods were used to investigate and demonstrate the possibility of obtaining highly loaded mixed aluminum–nickel oxide systems, with a nickel content of ca. 33 wt.%, using a hydrochemical treatment at room temperature or a hydrothermal treatment of suspensions of the product of the centrifugal thermal activation of gibbsite in aqueous solutions of nickel nitrate. It was shown that the thermal treatment of xerogels—hydrochemical interaction products—in the range of 350–850 °C led to the formation of NiO phases and highly dispersed solid solutions of nickel based on the NiAl2O4 spinel structure, with different ratios and a high specific surface area of 140–200 m2/g. A hydrochemical treatment of suspensions at room temperature ensures that the predominant formation of the NiO phase is distributed over the surface of the alumina matrix after calcination, whereas hydrothermal treatment at 150 °C leads to a deeper interaction of the suspension components at the treatment step, which occurs after the thermal treatment of the formed xerogel in the predominant formation of poorly crystallized NiAl2O4 spinel (“protospinel”). The considered method makes it possible to obtain complex aluminum–nickel oxide systems with different phase ratios, decreases the number of initial reagents and synthesis steps, completely excludes waste and diminishes the total amount of nitrates by 75 wt.% compared to the classical nitrate scheme for the coprecipitation of compounds with a similar elemental composition.
{"title":"Low-Waste Synthesis and Properties of Highly Dispersed NiO·Al2O3 Mixed Oxides Based on the Products of Centrifugal Thermal Activation of Gibbsite","authors":"A. Zhuzhgov, L. Isupova, E. A. Suprun, A. Gorkusha","doi":"10.3390/chemengineering7040071","DOIUrl":"https://doi.org/10.3390/chemengineering7040071","url":null,"abstract":"This study revealed an increased reactivity of centrifugally thermoactivated products of gibbsite toward aqueous solutions of nickel nitrate at room temperature as well as under hydrothermal conditions. X-ray, thermal, microscopy, adsorption and chemical analysis methods were used to investigate and demonstrate the possibility of obtaining highly loaded mixed aluminum–nickel oxide systems, with a nickel content of ca. 33 wt.%, using a hydrochemical treatment at room temperature or a hydrothermal treatment of suspensions of the product of the centrifugal thermal activation of gibbsite in aqueous solutions of nickel nitrate. It was shown that the thermal treatment of xerogels—hydrochemical interaction products—in the range of 350–850 °C led to the formation of NiO phases and highly dispersed solid solutions of nickel based on the NiAl2O4 spinel structure, with different ratios and a high specific surface area of 140–200 m2/g. A hydrochemical treatment of suspensions at room temperature ensures that the predominant formation of the NiO phase is distributed over the surface of the alumina matrix after calcination, whereas hydrothermal treatment at 150 °C leads to a deeper interaction of the suspension components at the treatment step, which occurs after the thermal treatment of the formed xerogel in the predominant formation of poorly crystallized NiAl2O4 spinel (“protospinel”). The considered method makes it possible to obtain complex aluminum–nickel oxide systems with different phase ratios, decreases the number of initial reagents and synthesis steps, completely excludes waste and diminishes the total amount of nitrates by 75 wt.% compared to the classical nitrate scheme for the coprecipitation of compounds with a similar elemental composition.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43066350","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 : 2023-07-27DOI: 10.3390/chemengineering7040069
Sela Kong, Tongor Keang, Monyneath Bunthan, Manit Say, Yukleav Nat, C. Tan, Reasmey Tan
Sacha inchi oil (SIO) extraction has been extensively studied using various oil extraction techniques to achieve a high oil recovery. However, most studies relied on heat-based methods, which led to compromised oil quality and reduced nutritional values, particularly polyunsaturated fatty acids (omega-3 and omega-6), vitamin E, and phenolic compounds. To address these concerns, this study employed a hydraulic cold-pressed extraction (HCPE) technique for extracting SIO aiming to enhance oil yield while preserving its nutritional integrity. During the HCPE process of sacha inchi seeds (SIS), conducted at a constant temperature of 25 ± 1 °C, pressures and pressing times were varied within the range of 30–50 MPa and 10–30 min, respectively, to determine their impact on SIO yields. The results revealed that both pressure and pressing time significantly influenced the yields of SIO (p < 0.05), with the highest oil recovery of 86.31 wt.% on a wet basis achieved at 50 MPa for 30 min. Regarding physicochemical properties, the peroxide values (5.71–9.07 meq/kg), iodine values (176.22–197.76 g I2/100 g), acid values (1.82–2.16 mg KOH/g), and percentage of free fatty acids (0.91–1.08 wt.% as oleic acid) were found to be influenced by pressure and pressing time (p < 0.05). Additionally, the color variation by L* (34.22–35.17), −a* (0.39–0.81), and b* (3.48–5.62) changed with each oil yield. Notably, the high iodine value in SIO indicated a substantial content of polyunsaturated fatty acids, including omega-3 (40.86%), omega-6 (40.87%), and omega-9 (10.20%). Furthermore, a comparison with solvent extraction methods demonstrated that HCPE exhibited similar efficiency in extracting SIO, offering additional advantage in terms of its cold-pressed condition, eliminating of solvent use, simplicity, short extraction time, and higher oil recovery.
{"title":"Hydraulic Cold-Pressed Extraction of Sacha Inchi Seeds: Oil Yield and Its Physicochemical Properties","authors":"Sela Kong, Tongor Keang, Monyneath Bunthan, Manit Say, Yukleav Nat, C. Tan, Reasmey Tan","doi":"10.3390/chemengineering7040069","DOIUrl":"https://doi.org/10.3390/chemengineering7040069","url":null,"abstract":"Sacha inchi oil (SIO) extraction has been extensively studied using various oil extraction techniques to achieve a high oil recovery. However, most studies relied on heat-based methods, which led to compromised oil quality and reduced nutritional values, particularly polyunsaturated fatty acids (omega-3 and omega-6), vitamin E, and phenolic compounds. To address these concerns, this study employed a hydraulic cold-pressed extraction (HCPE) technique for extracting SIO aiming to enhance oil yield while preserving its nutritional integrity. During the HCPE process of sacha inchi seeds (SIS), conducted at a constant temperature of 25 ± 1 °C, pressures and pressing times were varied within the range of 30–50 MPa and 10–30 min, respectively, to determine their impact on SIO yields. The results revealed that both pressure and pressing time significantly influenced the yields of SIO (p < 0.05), with the highest oil recovery of 86.31 wt.% on a wet basis achieved at 50 MPa for 30 min. Regarding physicochemical properties, the peroxide values (5.71–9.07 meq/kg), iodine values (176.22–197.76 g I2/100 g), acid values (1.82–2.16 mg KOH/g), and percentage of free fatty acids (0.91–1.08 wt.% as oleic acid) were found to be influenced by pressure and pressing time (p < 0.05). Additionally, the color variation by L* (34.22–35.17), −a* (0.39–0.81), and b* (3.48–5.62) changed with each oil yield. Notably, the high iodine value in SIO indicated a substantial content of polyunsaturated fatty acids, including omega-3 (40.86%), omega-6 (40.87%), and omega-9 (10.20%). Furthermore, a comparison with solvent extraction methods demonstrated that HCPE exhibited similar efficiency in extracting SIO, offering additional advantage in terms of its cold-pressed condition, eliminating of solvent use, simplicity, short extraction time, and higher oil recovery.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48851857","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 : 2023-07-27DOI: 10.3390/chemengineering7040070
R. Pal
The viscosity models for concentrated suspensions of unimodal hard spheres published in the twenty-first century are reviewed, compared, and evaluated using a large pool of available experimental data. The Pal viscosity model for unimodal suspensions is the best available model in that the predictions of this model agree very well with the low (zero)-shear experimental relative viscosity data for coarse suspensions, nanosuspensions, and coarse suspensions thickened by starch nanoparticles. The average percentage error in model predictions is less than 6.5%. Finally, the viscous behavior of concentrated multimodal suspensions is simulated using the Pal model for unimodal suspensions.
{"title":"Recent Progress in the Viscosity Modeling of Concentrated Suspensions of Unimodal Hard Spheres","authors":"R. Pal","doi":"10.3390/chemengineering7040070","DOIUrl":"https://doi.org/10.3390/chemengineering7040070","url":null,"abstract":"The viscosity models for concentrated suspensions of unimodal hard spheres published in the twenty-first century are reviewed, compared, and evaluated using a large pool of available experimental data. The Pal viscosity model for unimodal suspensions is the best available model in that the predictions of this model agree very well with the low (zero)-shear experimental relative viscosity data for coarse suspensions, nanosuspensions, and coarse suspensions thickened by starch nanoparticles. The average percentage error in model predictions is less than 6.5%. Finally, the viscous behavior of concentrated multimodal suspensions is simulated using the Pal model for unimodal suspensions.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42140348","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 : 2023-07-26DOI: 10.3390/chemengineering7040068
Lena-Marie Ränger, Yannick Waibel, Thomas Grützner
For an in-depth investigation of the separation process in small-scale distillation columns, knowledge about the exact vapor load inside the column is highly important. However, since columns with small diameters have a comparatively high surface-to-volume ratio, heat losses have a significant impact on fluid dynamics, as they lead to unwanted condensation, and thus, to changes in the internal flows. This work presents a procedure used to measure heat losses in a 9.6 m high distillation column with three partially parallel segments (multiple dividing wall column). The evaporator is made of stainless steel, and the column walls are made of double-walled, evacuated, mirrored glass, and additionally, these can be heated. It is found that significant amounts of heat are lost in the evaporator. Throughout the column height, around 0.8 kW are additionally lost, even with external wall heating. To determine the main reason for this significant loss, thermal images are taken, indicating that the problem mainly arises because of the flanges. Based on this, it can be concluded that proper insulation and additional heating jackets for the column walls are highly recommended for small-scale distillation columns in order to increase their thermal efficiency.
{"title":"Experimental Investigation of Heat Losses in a Pilot-Scale Multiple Dividing Wall Distillation Column with Three Parallel Sections","authors":"Lena-Marie Ränger, Yannick Waibel, Thomas Grützner","doi":"10.3390/chemengineering7040068","DOIUrl":"https://doi.org/10.3390/chemengineering7040068","url":null,"abstract":"For an in-depth investigation of the separation process in small-scale distillation columns, knowledge about the exact vapor load inside the column is highly important. However, since columns with small diameters have a comparatively high surface-to-volume ratio, heat losses have a significant impact on fluid dynamics, as they lead to unwanted condensation, and thus, to changes in the internal flows. This work presents a procedure used to measure heat losses in a 9.6 m high distillation column with three partially parallel segments (multiple dividing wall column). The evaporator is made of stainless steel, and the column walls are made of double-walled, evacuated, mirrored glass, and additionally, these can be heated. It is found that significant amounts of heat are lost in the evaporator. Throughout the column height, around 0.8 kW are additionally lost, even with external wall heating. To determine the main reason for this significant loss, thermal images are taken, indicating that the problem mainly arises because of the flanges. Based on this, it can be concluded that proper insulation and additional heating jackets for the column walls are highly recommended for small-scale distillation columns in order to increase their thermal efficiency.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48536881","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 : 2023-07-24DOI: 10.3390/chemengineering7040067
Juliana de Araujo, W. Silvestre, G. Pauletti, L. Muniz
This study aimed to evaluate the extraction of Corymbia citriodora (Hook.) K.D.Hill and L.A.S.Johnson essential oil by steam distillation under reduced pressure. Yield and composition of the essential oils obtained at different system pressures were analyzed. System pressure had a significant influence on essential oil yield, resulting in a reduction of 78.6% when the pressure was reduced from 690 Torr to 240 Torr. There were also changes in essential oil composition, with an increase in citronellol content (oxygenated monoterpene). However, the major compound (citronellal) remained at a high content in all tests. Regarding the extracted mass of the major compounds (citronellal, citronellol), there was a significant reduction for all when the system pressure was reduced. Although the reduction in the pressure of the system caused a reduction in oil yield, it was possible to carry out the steps of extraction and purification of the major compound simultaneously. Reduced pressure extraction may decrease process time, increasing its efficiency and reducing costs in the extraction of essential oils.
{"title":"Influence of the Absolute Pressure of the Extraction System on the Yield and Composition of Corymbia citriodora (Hook.) K.D.Hill and L.A.S.Johnson Leaf Essential Oil Extracted by Steam Distillation","authors":"Juliana de Araujo, W. Silvestre, G. Pauletti, L. Muniz","doi":"10.3390/chemengineering7040067","DOIUrl":"https://doi.org/10.3390/chemengineering7040067","url":null,"abstract":"This study aimed to evaluate the extraction of Corymbia citriodora (Hook.) K.D.Hill and L.A.S.Johnson essential oil by steam distillation under reduced pressure. Yield and composition of the essential oils obtained at different system pressures were analyzed. System pressure had a significant influence on essential oil yield, resulting in a reduction of 78.6% when the pressure was reduced from 690 Torr to 240 Torr. There were also changes in essential oil composition, with an increase in citronellol content (oxygenated monoterpene). However, the major compound (citronellal) remained at a high content in all tests. Regarding the extracted mass of the major compounds (citronellal, citronellol), there was a significant reduction for all when the system pressure was reduced. Although the reduction in the pressure of the system caused a reduction in oil yield, it was possible to carry out the steps of extraction and purification of the major compound simultaneously. Reduced pressure extraction may decrease process time, increasing its efficiency and reducing costs in the extraction of essential oils.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44112096","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}
Cosmetics have always been in demand across the globe among people of all age groups. In the modern cosmetic world, nanostructured materials have proven hugely advantageous in producing cosmeceuticals or ‘nano-cosmeceuticals’ and various beauty products. The application of nanostructured materials in cosmetic products possesses some challenges in terms of short- and long-term safety and environmental issues, despite their growing popularity. The nanostructured particles in cosmeceuticals provide a targeted route of administration due to their high penetrability, site selectivity, high effectiveness, prolonged activity, and drug encapsulation potential. However, standard methods for toxicity evaluation may not be relevant for cosmeceuticals, leading to the need for an alternative methodology. This review article compiles detailed descriptions of all significant aspects of nanostructured materials in the cosmetics industry, which include the synthesis and characterization of relevant nanostructured materials for cosmeceuticals, state-of-the-art practices, mechanisms for the synthesis of advanced materials, toxicological concerns in terms of health risks in humans, and environmental concerns. Also, a proposal for new approaches in terms of regulatory measures to mitigate these problems has been suggested. The primary focus of this article is to provide a comprehensive outlook on this subject area and contribute to the exploration of new prospects and emerging roles of nanostructured materials in the cosmetics industry.
{"title":"Functional Nanostructured Materials in the Cosmetics Industry: A Review","authors":"Anjali Sharma, Pooja Agarwal, Zahra Sebghatollahi, Neelima Mahato","doi":"10.3390/chemengineering7040066","DOIUrl":"https://doi.org/10.3390/chemengineering7040066","url":null,"abstract":"Cosmetics have always been in demand across the globe among people of all age groups. In the modern cosmetic world, nanostructured materials have proven hugely advantageous in producing cosmeceuticals or ‘nano-cosmeceuticals’ and various beauty products. The application of nanostructured materials in cosmetic products possesses some challenges in terms of short- and long-term safety and environmental issues, despite their growing popularity. The nanostructured particles in cosmeceuticals provide a targeted route of administration due to their high penetrability, site selectivity, high effectiveness, prolonged activity, and drug encapsulation potential. However, standard methods for toxicity evaluation may not be relevant for cosmeceuticals, leading to the need for an alternative methodology. This review article compiles detailed descriptions of all significant aspects of nanostructured materials in the cosmetics industry, which include the synthesis and characterization of relevant nanostructured materials for cosmeceuticals, state-of-the-art practices, mechanisms for the synthesis of advanced materials, toxicological concerns in terms of health risks in humans, and environmental concerns. Also, a proposal for new approaches in terms of regulatory measures to mitigate these problems has been suggested. The primary focus of this article is to provide a comprehensive outlook on this subject area and contribute to the exploration of new prospects and emerging roles of nanostructured materials in the cosmetics industry.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41641351","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 : 2023-07-21DOI: 10.3390/chemengineering7040065
A. Buasri, Phensuda Sirikoom, Sirinan Pattane, Orapharn Buachum, V. Loryuenyong
In the present investigation, response surface methodology (RSM) and machine learning (ML) are applied to the biodiesel production process via acid-catalyzed transesterification and esterification of triglyceride (TG). In order to optimize the production of biodiesel from used cooking oil (UCO) in a microwave reactor, these models are also compared. During the process, Box–Behnken design (BBD) and an artificial neural network (ANN) were used to evaluate the effect of the catalyst content (3.0–7.0 wt.%), methanol/UCO mole ratio (12:1–18:1), and irradiation time (5.0–9.0 min). The process conditions were adjusted and developed to predict the highest biodiesel yield using BBD with the RSM approach and an ANN model. With optimal process parameters of 4.94 wt.% catalyst content, 16.76:1 methanol/UCO mole ratio, and 8.13 min of irradiation time, a yield of approximately 98.62% was discovered. The coefficient of determination (R2) for the BBD model was found to be 0.9988, and the correlation coefficient (R) for the ANN model was found to be 0.9994. According to the findings, applying RSM and ANN models is advantageous when optimizing the biodiesel manufacturing process as well as making predictions about it. This renewable and environmentally friendly process has the potential to provide a sustainable route for the synthesis of high-quality biodiesel from waste oil with a low cost and high acid value.
{"title":"Process Optimization of Biodiesel from Used Cooking Oil in a Microwave Reactor: A Case of Machine Learning and Box–Behnken Design","authors":"A. Buasri, Phensuda Sirikoom, Sirinan Pattane, Orapharn Buachum, V. Loryuenyong","doi":"10.3390/chemengineering7040065","DOIUrl":"https://doi.org/10.3390/chemengineering7040065","url":null,"abstract":"In the present investigation, response surface methodology (RSM) and machine learning (ML) are applied to the biodiesel production process via acid-catalyzed transesterification and esterification of triglyceride (TG). In order to optimize the production of biodiesel from used cooking oil (UCO) in a microwave reactor, these models are also compared. During the process, Box–Behnken design (BBD) and an artificial neural network (ANN) were used to evaluate the effect of the catalyst content (3.0–7.0 wt.%), methanol/UCO mole ratio (12:1–18:1), and irradiation time (5.0–9.0 min). The process conditions were adjusted and developed to predict the highest biodiesel yield using BBD with the RSM approach and an ANN model. With optimal process parameters of 4.94 wt.% catalyst content, 16.76:1 methanol/UCO mole ratio, and 8.13 min of irradiation time, a yield of approximately 98.62% was discovered. The coefficient of determination (R2) for the BBD model was found to be 0.9988, and the correlation coefficient (R) for the ANN model was found to be 0.9994. According to the findings, applying RSM and ANN models is advantageous when optimizing the biodiesel manufacturing process as well as making predictions about it. This renewable and environmentally friendly process has the potential to provide a sustainable route for the synthesis of high-quality biodiesel from waste oil with a low cost and high acid value.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47469229","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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