Pub Date : 2024-01-01DOI: 10.3390/chemengineering8010008
B. Dossumova, L. Sassykova, T. Shakiyeva, D. Muktaly, A. Batyrbayeva, M. A. Kozhaisakova
In this work, the synthesis of magnetite nanoparticles and catalysts based on it stabilized with silicon and aluminum oxides was carried out. It is revealed that the stabilization of the magnetite surface by using aluminum and silicon oxides leads to a decrease in the size of magnetite nanocrystals in nanocomposites (particle diameter less than ~10 nm). The catalytic activity of the obtained catalysts was evaluated during the oxidation reaction of phenol, pyrocatechin and cresol with oxygen. It is well known that phenolic compounds are among the most dangerous water pollutants. The effect of phenol concentration and the effect of temperature (303–333 K) on the rate of oxidation of phenol to Fe3O4/SiO2 has been studied. It has been determined that the dependence of the oxidation rate of phenol on the initial concentration of phenol in solution is described by a first-order equation. At temperatures of 303–313 K, incomplete absorption of the calculated amount of oxygen is observed, and the analysis data indicate the non-selective oxidation of phenol. Intermediate products, such as catechin, hydroquinone, formic acid, oxidation products, were found. The results of UV and IR spectroscopy showed that catalysts based on magnetite Fe3O4 are effective in the oxidation of phenol with oxygen. In the UV spectrum of the product in the wavelength range 190–1100 nm, there is an absorption band at a wavelength of 240–245 nm and a weak band at 430 nm, which is characteristic of benzoquinone. In the IR spectrum of the product, absorption bands were detected in the region of 1644 cm−1, which is characteristic of the oscillations of the C=O bonds of the carbonyl group of benzoquinone. The peaks also found at 1353 cm−1 and 1229 cm−1 may be due to vibrations of the C-H and C-C bonds of the quinone ring. It was found that among the synthesized catalysts, the Fe3O4/SiO2 catalyst demonstrated the greatest activity in the reaction of liquid-phase oxidation of phenol.
{"title":"Catalysts Based on Iron Oxides for Wastewater Purification from Phenolic Compounds: Synthesis, Physicochemical Analysis, Determination of Catalytic Activity","authors":"B. Dossumova, L. Sassykova, T. Shakiyeva, D. Muktaly, A. Batyrbayeva, M. A. Kozhaisakova","doi":"10.3390/chemengineering8010008","DOIUrl":"https://doi.org/10.3390/chemengineering8010008","url":null,"abstract":"In this work, the synthesis of magnetite nanoparticles and catalysts based on it stabilized with silicon and aluminum oxides was carried out. It is revealed that the stabilization of the magnetite surface by using aluminum and silicon oxides leads to a decrease in the size of magnetite nanocrystals in nanocomposites (particle diameter less than ~10 nm). The catalytic activity of the obtained catalysts was evaluated during the oxidation reaction of phenol, pyrocatechin and cresol with oxygen. It is well known that phenolic compounds are among the most dangerous water pollutants. The effect of phenol concentration and the effect of temperature (303–333 K) on the rate of oxidation of phenol to Fe3O4/SiO2 has been studied. It has been determined that the dependence of the oxidation rate of phenol on the initial concentration of phenol in solution is described by a first-order equation. At temperatures of 303–313 K, incomplete absorption of the calculated amount of oxygen is observed, and the analysis data indicate the non-selective oxidation of phenol. Intermediate products, such as catechin, hydroquinone, formic acid, oxidation products, were found. The results of UV and IR spectroscopy showed that catalysts based on magnetite Fe3O4 are effective in the oxidation of phenol with oxygen. In the UV spectrum of the product in the wavelength range 190–1100 nm, there is an absorption band at a wavelength of 240–245 nm and a weak band at 430 nm, which is characteristic of benzoquinone. In the IR spectrum of the product, absorption bands were detected in the region of 1644 cm−1, which is characteristic of the oscillations of the C=O bonds of the carbonyl group of benzoquinone. The peaks also found at 1353 cm−1 and 1229 cm−1 may be due to vibrations of the C-H and C-C bonds of the quinone ring. It was found that among the synthesized catalysts, the Fe3O4/SiO2 catalyst demonstrated the greatest activity in the reaction of liquid-phase oxidation of phenol.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"48 11","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139126974","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 : 2024-01-01DOI: 10.3390/chemengineering8010007
Suchart Kreesaeng, B. Chalermsinsuwan, P. Piumsomboon
In multi-solid, particle-size fluidized bed reactor systems, segregation is commonly observed. When segregation occurred, small solid particles were entrained to the top of the bed and escaped from the reactor. During the combustion process, the small solid particles that escaped from the boiler were burned and subjected to damage around the cyclone separator. This study then employed a computational fluid dynamics approach to investigate solid particle behavior in the reactor using three different sizes of solid particles. The effects of baffle insertion, baffle angle, stage number, and its arrangement were examined. The percentage of segregation was calculated to compare behavior among different reactor systems. The insertion of 45-degree baffles resulted in reduced segregation behavior compared to cases without baffles and with 90-degree baffles, attributed to solid hindering and collision phenomena. Additionally, a double-stage baffle with any arrangement could reduce segregation behavior. The best arrangement was “above-arrangement” due to particles hindering, swirling, and accumulating between the baffle stages. Therefore, to diminish segregation behavior and enhance combustion chemical reactions, the insertion of baffles in the reactor zone is recommended.
{"title":"Effect of Inserting Baffles on the Solid Particle Segregation Behavior in Fluidized Bed Reactor: A Computational Study","authors":"Suchart Kreesaeng, B. Chalermsinsuwan, P. Piumsomboon","doi":"10.3390/chemengineering8010007","DOIUrl":"https://doi.org/10.3390/chemengineering8010007","url":null,"abstract":"In multi-solid, particle-size fluidized bed reactor systems, segregation is commonly observed. When segregation occurred, small solid particles were entrained to the top of the bed and escaped from the reactor. During the combustion process, the small solid particles that escaped from the boiler were burned and subjected to damage around the cyclone separator. This study then employed a computational fluid dynamics approach to investigate solid particle behavior in the reactor using three different sizes of solid particles. The effects of baffle insertion, baffle angle, stage number, and its arrangement were examined. The percentage of segregation was calculated to compare behavior among different reactor systems. The insertion of 45-degree baffles resulted in reduced segregation behavior compared to cases without baffles and with 90-degree baffles, attributed to solid hindering and collision phenomena. Additionally, a double-stage baffle with any arrangement could reduce segregation behavior. The best arrangement was “above-arrangement” due to particles hindering, swirling, and accumulating between the baffle stages. Therefore, to diminish segregation behavior and enhance combustion chemical reactions, the insertion of baffles in the reactor zone is recommended.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"96 12","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139128644","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 : 2023-12-26DOI: 10.3390/chemengineering8010006
I. Anashkin, A. Klinov
Based on the TraPPE force field, previously unknown values of the parameters of the intermolecular interaction potential of trans-decalin were determined. Parametrization was carried out using experimental data on saturated vapor pressure and density at atmospheric pressure. The found parameters make it possible to adequately describe the boiling and condensation lines of trans-decalin and also predict the critical values of pressure, density, and temperature with satisfactory accuracy. Calculations of vapor-liquid phase equilibrium conditions for a binary CO2—trans-decalin mixture in supercritical conditions for CO2 were carried out. When quantitatively comparing the calculated values with experimental data, an underestimation of pressure at a temperature of 345.4 K by 30% is observed, which decreases to 5% for temperatures up to 525 K.
基于 TraPPE 力场，确定了反式癸醛分子间相互作用势参数的未知值。利用大气压下饱和蒸汽压和密度的实验数据进行了参数化。所发现的参数可以充分描述反式萘烷的沸腾和凝结线，并能准确预测压力、密度和温度的临界值。在二氧化碳的超临界条件下，对二氧化碳-反式萘烷二元混合物的汽液相平衡条件进行了计算。将计算值与实验数据进行定量比较后发现，在温度为 345.4 K 时，压力被低估了 30%，而在温度高达 525 K 时，压力被低估的比例下降到 5%。
{"title":"Force Field for Calculation of the Vapor-Liquid Phase Equilibrium of trans-Decalin","authors":"I. Anashkin, A. Klinov","doi":"10.3390/chemengineering8010006","DOIUrl":"https://doi.org/10.3390/chemengineering8010006","url":null,"abstract":"Based on the TraPPE force field, previously unknown values of the parameters of the intermolecular interaction potential of trans-decalin were determined. Parametrization was carried out using experimental data on saturated vapor pressure and density at atmospheric pressure. The found parameters make it possible to adequately describe the boiling and condensation lines of trans-decalin and also predict the critical values of pressure, density, and temperature with satisfactory accuracy. Calculations of vapor-liquid phase equilibrium conditions for a binary CO2—trans-decalin mixture in supercritical conditions for CO2 were carried out. When quantitatively comparing the calculated values with experimental data, an underestimation of pressure at a temperature of 345.4 K by 30% is observed, which decreases to 5% for temperatures up to 525 K.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"29 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155783","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 : 2023-12-20DOI: 10.3390/chemengineering8010003
F. Chiampo
Ultrafiltration is a well-known operation, widely used in food processing, especially to concentrate selectively liquid compounds. However, so far, it has been mainly used to change concentration and/or clarify liquids with low viscosity. Ultrafiltration has seldomly been applied to viscous fluids. In this study, it was used to increase the consistency of fruit pulps, without changing their taste and organoleptic properties. This paper reports the findings achieved in experimental runs carried out on a pilot plant, equipped with four ultrafiltration tubular membranes (total surface area = 0.8 m2). Raw fruit pulps, namely, apple, apricot, and pear, were used to study the influence of the operative parameters on the permeate flux and organoleptic properties of the final products (retentate and permeate). The flow rate was in the range of 3.0–5.1 m3/h, at 50 °C. The influence of temperature on the permeate flux was checked, with one run with apple pulp at 20 °C. As expected, the findings show that high flow rate and temperature improve the permeate flux. Membranes show different performance in permeate flux for the tested pulps. This is probably due to their different chemical and physical composition, which could be responsible for different fouling of the membrane and, as a consequence, a different resistance to the permeate flow. The final products have the same taste as the raw ones, and each of them can be used as it is or as an ingredient. These results have a technological relevance, and, besides, the study shows a methodology for future applications of ultrafiltration.
{"title":"Ultrafiltration to Increase the Consistency of Fruit Pulps: The Role of Permeate Flux","authors":"F. Chiampo","doi":"10.3390/chemengineering8010003","DOIUrl":"https://doi.org/10.3390/chemengineering8010003","url":null,"abstract":"Ultrafiltration is a well-known operation, widely used in food processing, especially to concentrate selectively liquid compounds. However, so far, it has been mainly used to change concentration and/or clarify liquids with low viscosity. Ultrafiltration has seldomly been applied to viscous fluids. In this study, it was used to increase the consistency of fruit pulps, without changing their taste and organoleptic properties. This paper reports the findings achieved in experimental runs carried out on a pilot plant, equipped with four ultrafiltration tubular membranes (total surface area = 0.8 m2). Raw fruit pulps, namely, apple, apricot, and pear, were used to study the influence of the operative parameters on the permeate flux and organoleptic properties of the final products (retentate and permeate). The flow rate was in the range of 3.0–5.1 m3/h, at 50 °C. The influence of temperature on the permeate flux was checked, with one run with apple pulp at 20 °C. As expected, the findings show that high flow rate and temperature improve the permeate flux. Membranes show different performance in permeate flux for the tested pulps. This is probably due to their different chemical and physical composition, which could be responsible for different fouling of the membrane and, as a consequence, a different resistance to the permeate flow. The final products have the same taste as the raw ones, and each of them can be used as it is or as an ingredient. These results have a technological relevance, and, besides, the study shows a methodology for future applications of ultrafiltration.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"270 ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139170731","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 : 2023-12-20DOI: 10.3390/chemengineering8010004
Sasitorn Boonkerd, Lek Wantha
Protein crystallization plays a crucial role in the food and pharmaceutical industries, enhancing product quality and efficiency by improving purity and controlled particle characteristics. This study focused on the crystallization of the versatile protein papain, extracted from papaya. Antisolvent crystallization was performed. This method is cost-effective and is a simple and energy-efficient approach. Beyond protein crystal production, the antisolvent crystallization process serves as a method for encapsulating active pharmaceutical ingredients (APIs). The study investigated organic solvents like ethanol, acetone, and acetonitrile as potential antisolvents. Additionally, the impact of variables such as the solvent-to-antisolvent (S:AS) volume ratio and papain concentration on particle size, particle size distribution, zeta potential, crystallization yield, and residual activity of papain crystals were examined. Ethanol emerged as the optimal antisolvent, reducing the solubility of papain and preserving papain’s crystalline structure with minimal activity loss. Optimal conditions were identified at a 1:4 S:AS volume ratio and a papain concentration of 30 mg/mL, resulting in nanosized spherical crystals with a high yield and preserved activity. This research underscored the crucial role of thoughtful parameter selection in antisolvent crystallization to achieve specific particle characteristics while maintaining the functionality of the crystallized substance.
{"title":"Antisolvent Crystallization of Papain","authors":"Sasitorn Boonkerd, Lek Wantha","doi":"10.3390/chemengineering8010004","DOIUrl":"https://doi.org/10.3390/chemengineering8010004","url":null,"abstract":"Protein crystallization plays a crucial role in the food and pharmaceutical industries, enhancing product quality and efficiency by improving purity and controlled particle characteristics. This study focused on the crystallization of the versatile protein papain, extracted from papaya. Antisolvent crystallization was performed. This method is cost-effective and is a simple and energy-efficient approach. Beyond protein crystal production, the antisolvent crystallization process serves as a method for encapsulating active pharmaceutical ingredients (APIs). The study investigated organic solvents like ethanol, acetone, and acetonitrile as potential antisolvents. Additionally, the impact of variables such as the solvent-to-antisolvent (S:AS) volume ratio and papain concentration on particle size, particle size distribution, zeta potential, crystallization yield, and residual activity of papain crystals were examined. Ethanol emerged as the optimal antisolvent, reducing the solubility of papain and preserving papain’s crystalline structure with minimal activity loss. Optimal conditions were identified at a 1:4 S:AS volume ratio and a papain concentration of 30 mg/mL, resulting in nanosized spherical crystals with a high yield and preserved activity. This research underscored the crucial role of thoughtful parameter selection in antisolvent crystallization to achieve specific particle characteristics while maintaining the functionality of the crystallized substance.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"81 14","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138957960","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 : 2023-12-19DOI: 10.3390/chemengineering8010001
K. Kini, Muddu Madakyaru, F. Harrou, Mukund Kumar Menon, Ying Sun
Fault detection is crucial in maintaining reliability, safety, and consistent product quality in chemical engineering processes. Accurate fault detection allows for identifying anomalies, signaling deviations from the system’s nominal behavior, ensuring the system operates within desired performance parameters, and minimizing potential losses. This paper presents a novel semi-supervised data-based monitoring technique for fault detection in multivariate processes. To this end, the proposed approach merges the capabilities of Principal Component Analysis (PCA) for dimensionality reduction and feature extraction with the Kolmogorov–Smirnov (KS)-based scheme for fault detection. The KS indicator is computed between the two distributions in a moving window of fixed length, allowing it to capture sensitive details that enhance the detection of faults. Moreover, no labeling is required when using this fault detection approach, making it flexible in practice. The performance of the proposed PCA–KS strategy is assessed for different sensor faults on benchmark processes, specifically the Plug Flow Reactor (PFR) process and the benchmark Tennessee Eastman (TE) process. Different sensor faults, including bias, intermittent, and aging faults, are considered in this study to evaluate the proposed fault detection scheme. The results demonstrate that the proposed approach surpasses traditional PCA-based methods. Specifically, when applied to PFR data, it achieves a high average detection rate of 98.31% and a low false alarm rate of 0.25%. Similarly, when applied to the TE process, it provides a good average detection rate of 97.27% and a false alarm rate of 6.32%. These results underscore the efficacy of the proposed PCA–KS approach in enhancing the fault detection of high-dimensional processes.
{"title":"Improved Fault Detection in Chemical Engineering Processes via Non-Parametric Kolmogorov–Smirnov-Based Monitoring Strategy","authors":"K. Kini, Muddu Madakyaru, F. Harrou, Mukund Kumar Menon, Ying Sun","doi":"10.3390/chemengineering8010001","DOIUrl":"https://doi.org/10.3390/chemengineering8010001","url":null,"abstract":"Fault detection is crucial in maintaining reliability, safety, and consistent product quality in chemical engineering processes. Accurate fault detection allows for identifying anomalies, signaling deviations from the system’s nominal behavior, ensuring the system operates within desired performance parameters, and minimizing potential losses. This paper presents a novel semi-supervised data-based monitoring technique for fault detection in multivariate processes. To this end, the proposed approach merges the capabilities of Principal Component Analysis (PCA) for dimensionality reduction and feature extraction with the Kolmogorov–Smirnov (KS)-based scheme for fault detection. The KS indicator is computed between the two distributions in a moving window of fixed length, allowing it to capture sensitive details that enhance the detection of faults. Moreover, no labeling is required when using this fault detection approach, making it flexible in practice. The performance of the proposed PCA–KS strategy is assessed for different sensor faults on benchmark processes, specifically the Plug Flow Reactor (PFR) process and the benchmark Tennessee Eastman (TE) process. Different sensor faults, including bias, intermittent, and aging faults, are considered in this study to evaluate the proposed fault detection scheme. The results demonstrate that the proposed approach surpasses traditional PCA-based methods. Specifically, when applied to PFR data, it achieves a high average detection rate of 98.31% and a low false alarm rate of 0.25%. Similarly, when applied to the TE process, it provides a good average detection rate of 97.27% and a false alarm rate of 6.32%. These results underscore the efficacy of the proposed PCA–KS approach in enhancing the fault detection of high-dimensional processes.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" 831","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138960389","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 : 2023-12-19DOI: 10.3390/chemengineering8010002
Di Zhang
Initiated chemical vapor deposition is a unique solvent-free and completely dry vapor-phase deposition technique used to synthesize organic polymer films. In this process, an activated initiator, monomer, and carrier gas are introduced into the reaction chamber simultaneously. This technique has been widely adopted. However, if the monomer and initiator are introduced into the chamber in stages—allowing gas-phase monomer deposition and condensation first, followed by initiator introduction and controlling the monomer partial pressure to be higher than the saturated vapor pressure—non-spherical polymer nanoparticles with dome-like shapes can be obtained. This advanced iCVD technique is referred to as the “Condensed Droplet Polymerization Approach”. This high monomer partial pressure gas-phase deposition is not suitable for forming uniformly composed iCVD films; but interestingly, it can rapidly obtain polymer nanodomes (PNDs). Using CDP technology, Franklin polymerized multifunctional nanodomes in less than 45 s, demonstrating a wide range of continuous particle size variations, from sub-20 nanometers to over 1 micron. This rapid synthesis included a variety of functional polymer nanodomes in just a matter of seconds to minutes. This review discusses the crucial process conditions of the Condensed Droplet Polymerization (CDP) Approach for synthesizing PNDs. The main focus of the discussion was on the two-step method for synthesizing PNDs, where the nucleation mechanism of PNDs, factors influencing their size, and the effect of pressure on the distinct condensation of monomer vapor into polymer nanodomes and polymer films were extensively explored.
{"title":"Significant Progress of Initiated Chemical Vapor Deposition in Manufacturing Soft Non-spherical Nanoparticles: Upgrading to the Condensed Droplet Polymerization Approach and Key Technological Aspects","authors":"Di Zhang","doi":"10.3390/chemengineering8010002","DOIUrl":"https://doi.org/10.3390/chemengineering8010002","url":null,"abstract":"Initiated chemical vapor deposition is a unique solvent-free and completely dry vapor-phase deposition technique used to synthesize organic polymer films. In this process, an activated initiator, monomer, and carrier gas are introduced into the reaction chamber simultaneously. This technique has been widely adopted. However, if the monomer and initiator are introduced into the chamber in stages—allowing gas-phase monomer deposition and condensation first, followed by initiator introduction and controlling the monomer partial pressure to be higher than the saturated vapor pressure—non-spherical polymer nanoparticles with dome-like shapes can be obtained. This advanced iCVD technique is referred to as the “Condensed Droplet Polymerization Approach”. This high monomer partial pressure gas-phase deposition is not suitable for forming uniformly composed iCVD films; but interestingly, it can rapidly obtain polymer nanodomes (PNDs). Using CDP technology, Franklin polymerized multifunctional nanodomes in less than 45 s, demonstrating a wide range of continuous particle size variations, from sub-20 nanometers to over 1 micron. This rapid synthesis included a variety of functional polymer nanodomes in just a matter of seconds to minutes. This review discusses the crucial process conditions of the Condensed Droplet Polymerization (CDP) Approach for synthesizing PNDs. The main focus of the discussion was on the two-step method for synthesizing PNDs, where the nucleation mechanism of PNDs, factors influencing their size, and the effect of pressure on the distinct condensation of monomer vapor into polymer nanodomes and polymer films were extensively explored.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":" 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138962571","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 : 2023-12-15DOI: 10.3390/chemengineering7060118
G. O. Kalashnikova, D. V. Gryaznova, A. Baranchikov, Sergey N. Britvin, V. Yakovenchuk, G. O. Samburov, V. Veselova, Aleksandra Y. Pulyalina, Y. Pakhomovsky, A. Bazai, M. Y. Glazunova, A. A. Shirokaya, Irina V. Kozerozhets, Anatoly I. Nikolaev, Vladimir K. Ivanov
Titanosilicates comprise a broad class of materials with promising technological applications. The typical obstacle that restricts their industrial applicability is the high manufacturing cost due to the use of specific organotitanium precursors. We herein report a new approach to the synthesis of titanosilicates using an inexpensive inorganic precursor, ammonium titanyl sulfate (ATS or STA), (NH4)2TiO(SO4)2∙H2O. The latter is an intermediate in the processing of titanium-bearing concentrates produced from apatite-nepheline ores. In this paper, the new synthetic approach is exemplified by the microwave-assisted synthesis of IONSIVE-911, one of the most effective Cs-ion scavengers. The method can be modified to synthesize various titanosilicate compounds.
{"title":"Microwave-Assisted Synthesis of Titanosilicates Using a Precursor Produced from Titanium Ore Concentrate","authors":"G. O. Kalashnikova, D. V. Gryaznova, A. Baranchikov, Sergey N. Britvin, V. Yakovenchuk, G. O. Samburov, V. Veselova, Aleksandra Y. Pulyalina, Y. Pakhomovsky, A. Bazai, M. Y. Glazunova, A. A. Shirokaya, Irina V. Kozerozhets, Anatoly I. Nikolaev, Vladimir K. Ivanov","doi":"10.3390/chemengineering7060118","DOIUrl":"https://doi.org/10.3390/chemengineering7060118","url":null,"abstract":"Titanosilicates comprise a broad class of materials with promising technological applications. The typical obstacle that restricts their industrial applicability is the high manufacturing cost due to the use of specific organotitanium precursors. We herein report a new approach to the synthesis of titanosilicates using an inexpensive inorganic precursor, ammonium titanyl sulfate (ATS or STA), (NH4)2TiO(SO4)2∙H2O. The latter is an intermediate in the processing of titanium-bearing concentrates produced from apatite-nepheline ores. In this paper, the new synthetic approach is exemplified by the microwave-assisted synthesis of IONSIVE-911, one of the most effective Cs-ion scavengers. The method can be modified to synthesize various titanosilicate compounds.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"222 22","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138996976","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 : 2023-12-06DOI: 10.3390/chemengineering7060117
P. Yadav, S. Gupta, Surendra Kumar Sharma
This article proposes a better alternative method to prepare CNT antifreeze nanofluid in EG/water by modifying the conventional method that requires long hours of sonication. Sonicating a sample for long hours is time and energy consuming and may deform the structure of CNT. In the modified method, the nanofluid preparation was carried out by dispersion of CNT in EG via sonication followed by adding water and again sonication. The study shows that nanofluid could be prepared in less sonication time of 1.5 h compared to the 5 h required in the conventional method. FTIR spectroscopy revealed that interaction of EG with CNT occurs via trans conformation resulting in greater stabilization and better interaction of nanofluid prepared by this method (85 days) as compared to nanofluid prepared by the conventional method (50 days). The nanofluid prepared by this method has better physical–chemical properties compared to nanofluid prepared by the conventional method. The nanofluid prepared by this method showed higher stability and better physical–chemical properties at a lower sonication time. Hence it is a more effective and cost efficient technique for preparing CNT (EG/water) nanofluid.
{"title":"Evaluation of Stabilization and Physical–Chemical Properties of CNT Antifreeze Nanofluid Prepared in 50:50 EG/Water by Modified Strategy","authors":"P. Yadav, S. Gupta, Surendra Kumar Sharma","doi":"10.3390/chemengineering7060117","DOIUrl":"https://doi.org/10.3390/chemengineering7060117","url":null,"abstract":"This article proposes a better alternative method to prepare CNT antifreeze nanofluid in EG/water by modifying the conventional method that requires long hours of sonication. Sonicating a sample for long hours is time and energy consuming and may deform the structure of CNT. In the modified method, the nanofluid preparation was carried out by dispersion of CNT in EG via sonication followed by adding water and again sonication. The study shows that nanofluid could be prepared in less sonication time of 1.5 h compared to the 5 h required in the conventional method. FTIR spectroscopy revealed that interaction of EG with CNT occurs via trans conformation resulting in greater stabilization and better interaction of nanofluid prepared by this method (85 days) as compared to nanofluid prepared by the conventional method (50 days). The nanofluid prepared by this method has better physical–chemical properties compared to nanofluid prepared by the conventional method. The nanofluid prepared by this method showed higher stability and better physical–chemical properties at a lower sonication time. Hence it is a more effective and cost efficient technique for preparing CNT (EG/water) nanofluid.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"69 3","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138594550","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 : 2023-12-05DOI: 10.3390/chemengineering7060116
Xiaowei Tang, Kunyu Ju
Various methods, such as electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins, have been extensively employed for the removal of copper from nickel anolytes. However, these methods exhibit several significant drawbacks when applied in industrial settings. For instance, electrochemical purification fails to efficiently manage nickel anolyte solutions with low copper content. Chemical precipitation presents challenges in residue management and incurs high production costs for precipitants. Solvent extraction raises concerns related to toxicity, while the use of ion-exchange resins demands meticulous selection of suitable materials. In this review, we present a comprehensive review of the nickel removal methods used for nickel anolyte purification, electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins. We also examine the suitability and benefits of each technique in industrial settings. The ion-exchange method has drawn significant attention due to its strong selectivity and small adsorption quantity. The ion-exchange separation process does not generate any slag, and the ion-exchange resin can be recycled and reused; this method has great potential in a wide range of applications.
{"title":"Exploring Strategies for Copper Removal from Nickel Anolytes: A Review","authors":"Xiaowei Tang, Kunyu Ju","doi":"10.3390/chemengineering7060116","DOIUrl":"https://doi.org/10.3390/chemengineering7060116","url":null,"abstract":"Various methods, such as electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins, have been extensively employed for the removal of copper from nickel anolytes. However, these methods exhibit several significant drawbacks when applied in industrial settings. For instance, electrochemical purification fails to efficiently manage nickel anolyte solutions with low copper content. Chemical precipitation presents challenges in residue management and incurs high production costs for precipitants. Solvent extraction raises concerns related to toxicity, while the use of ion-exchange resins demands meticulous selection of suitable materials. In this review, we present a comprehensive review of the nickel removal methods used for nickel anolyte purification, electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins. We also examine the suitability and benefits of each technique in industrial settings. The ion-exchange method has drawn significant attention due to its strong selectivity and small adsorption quantity. The ion-exchange separation process does not generate any slag, and the ion-exchange resin can be recycled and reused; this method has great potential in a wide range of applications.","PeriodicalId":9755,"journal":{"name":"ChemEngineering","volume":"96 23","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138599891","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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