Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110097
Tristan Cole , Paul Ani , Ahmed Jasim , Zeyad Zeitoun , Joseph Smith
Reverse flow reactors are notable for their dynamic operation under unsteady state conditions, the minimization of energy use, and reduction of harmful greenhouse emissions. The main advantages offered by reverse flow reactors over conventional fixed bed reactors include enhanced reaction rates and reduced waste due to superior mixing and more efficient heat transfer. Sophisticated application of key principles of process intensification has facilitated the use of reverse flow reactors in numerous industrial applications including the oxidation of volatile organic compounds emissions, sulfuric acid production, reduction of NOx emissions from nitric acid production, steam-methane reforming for hydrogen production, and partial oxidation of methane for syngas production. This paper explores the potential of reverse flow reactors to promote sustainable chemical manufacturing processes with a reduced environmental impact across numerous industrial applications.
{"title":"Process intensification in reverse flow reactors to boost various industrial applications: A review","authors":"Tristan Cole , Paul Ani , Ahmed Jasim , Zeyad Zeitoun , Joseph Smith","doi":"10.1016/j.cep.2024.110097","DOIUrl":"10.1016/j.cep.2024.110097","url":null,"abstract":"<div><div>Reverse flow reactors are notable for their dynamic operation under unsteady state conditions, the minimization of energy use, and reduction of harmful greenhouse emissions. The main advantages offered by reverse flow reactors over conventional fixed bed reactors include enhanced reaction rates and reduced waste due to superior mixing and more efficient heat transfer. Sophisticated application of key principles of process intensification has facilitated the use of reverse flow reactors in numerous industrial applications including the oxidation of volatile organic compounds emissions, sulfuric acid production, reduction of NOx emissions from nitric acid production, steam-methane reforming for hydrogen production, and partial oxidation of methane for syngas production. This paper explores the potential of reverse flow reactors to promote sustainable chemical manufacturing processes with a reduced environmental impact across numerous industrial applications.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110097"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110138
Petr V. Zemlianskii , Alexander L. Kustov , Maria N. Timofeeva , Leonid M. Kustov
Herein, a literature review on the application of microwave irradiation (MW) for the synthesis of MFe2O4 spinels (M: Cu2+, Zn2+, Mn2+, Ni2+ and Co2+) and oxidation processes of organic pollutants as well as hydrogen production with the use of such catalysts was conducted. The main attention was focused on the tuning of the particle size of spinels and their physicochemical properties by using MW synthesis. The advantages of MW synthesis are shown in comparison with traditional thermal heating (TH). The physicochemical and catalytic properties of MFe2O4 spinel obtained under the conditions of MW and TH are compared.
{"title":"Microwave irradiation as an instrument for tuning of physicochemical and catalytic properties of MFe2O4 spinels","authors":"Petr V. Zemlianskii , Alexander L. Kustov , Maria N. Timofeeva , Leonid M. Kustov","doi":"10.1016/j.cep.2024.110138","DOIUrl":"10.1016/j.cep.2024.110138","url":null,"abstract":"<div><div>Herein, a literature review on the application of microwave irradiation (MW) for the synthesis of MFe<sub>2</sub>O<sub>4</sub> spinels (M: Cu<sup>2+</sup>, Zn<sup>2+</sup>, Mn<sup>2+</sup>, Ni<sup>2+</sup> and Co<sup>2+</sup>) and oxidation processes of organic pollutants as well as hydrogen production with the use of such catalysts was conducted. The main attention was focused on the tuning of the particle size of spinels and their physicochemical properties by using MW synthesis. The advantages of MW synthesis are shown in comparison with traditional thermal heating (TH). The physicochemical and catalytic properties of MFe<sub>2</sub>O<sub>4</sub> spinel obtained under the conditions of MW and TH are compared.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110138"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110093
Ahmed J. Aladily, Thamer J. Mohammed, Talib M. Albayati
Separation processes using membrane have increasingly gained attention due to their notable advancements in various areas, including designs, utilizing cutting-edge materials in the fabrication of membrane, production techniques and module engineering. However, it is still limitations especially membrane fouling. One of the promising techniques is coupling electrocoagulation (EC) with membrane to overcome this serious problem and energy saving on the other hand. This paper shows an overview of the typical configuration of integrated EC-membrane system and hybrid EC-membrane system and their applications in industrial wastewater treatment. Different combinations of integrated EC process with microfiltration (EC-MF), ultrafiltration (EC-UF), nanofiltration (EC-NF), and reverse osmosis (EC-RO) with detailed reactor design and case studies were explored. Case studies regarding the application for many sources of wastewater have been demonstrated. Moreover, all main factors affecting EC-membrane process such as; electrode material, inter -electrode distance, current Density, shape of the electrode, electrode arrangement, initial pH, concentration of anions, electrolyte conductivity, EC Time, agitation speed, type of power supply, operating temperature, and pollutant initial concentration were studied. Cost analysis equations also included. The critical analysis and recommendations presented in this review paper will significantly enhance the scientific understanding of the readers.
{"title":"Coupling of electrocoagulation and membrane in hybrid and integrated systems for wastewater treatment, focusing on trends of reactor designs, fundamentals, and factors affecting the process: A critical review","authors":"Ahmed J. Aladily, Thamer J. Mohammed, Talib M. Albayati","doi":"10.1016/j.cep.2024.110093","DOIUrl":"10.1016/j.cep.2024.110093","url":null,"abstract":"<div><div>Separation processes using membrane have increasingly gained attention due to their notable advancements in various areas, including designs, utilizing cutting-edge materials in the fabrication of membrane, production techniques and module engineering. However, it is still limitations especially membrane fouling. One of the promising techniques is coupling electrocoagulation (EC) with membrane to overcome this serious problem and energy saving on the other hand. This paper shows an overview of the typical configuration of integrated EC-membrane system and hybrid EC-membrane system and their applications in industrial wastewater treatment. Different combinations of integrated EC process with microfiltration (EC-MF), ultrafiltration (EC-UF), nanofiltration (EC-NF), and reverse osmosis (EC-RO) with detailed reactor design and case studies were explored. Case studies regarding the application for many sources of wastewater have been demonstrated. Moreover, all main factors affecting EC-membrane process such as; electrode material, inter -electrode distance, current Density, shape of the electrode, electrode arrangement, initial pH, concentration of anions, electrolyte conductivity, EC Time, agitation speed, type of power supply, operating temperature, and pollutant initial concentration were studied. Cost analysis equations also included. The critical analysis and recommendations presented in this review paper will significantly enhance the scientific understanding of the readers.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110093"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110091
Jia-hui Shi , Shi-jiao Li , Sheng-lin Yan , Zheng-hong Luo
Researching the regime transition of the subcooled flow is essential for designing high-performance heat exchangers. A high-speed camera platform is built to study the bubble behavior of the subcooled boiling of a water-ethanol mixture in a microchannel. Simultaneous synchronisation of thermodynamic transient characterisation and high speed flow visualisation. The flow in the microchannel can be divided into single-phase convection, isolated bubble, bubbly flow, and slug flow regions. The combination of micro-channel and multi-component coolant along with keeping the subcooled boiling within the bubbly flow region can improve the heat transfer performance. The wall effect in the microchannel will enhance the bubble-induced heat transfer and result in a reduced heat transfer performance under higher inlet velocity conditions. Compared with lower velocity of 0.05 m/s, the bubble departure frequency for higher velocity of 0.15 m/s decreased by a maximum of 2 times in the bubbly flow region. The heat transfer coefficient for the bubbly flow regime is found to be universally proportional to the void fraction for all conditions analysed in this paper. Hence, the manners that are beneficial for void fraction improvement can be utilized to regulate the heat transfer coefficient of the microchannel within the bubbly flow regime.
{"title":"Visualization study on temporal regime transition of multicomponent subcooled flow in microchannel","authors":"Jia-hui Shi , Shi-jiao Li , Sheng-lin Yan , Zheng-hong Luo","doi":"10.1016/j.cep.2024.110091","DOIUrl":"10.1016/j.cep.2024.110091","url":null,"abstract":"<div><div>Researching the regime transition of the subcooled flow is essential for designing high-performance heat exchangers. A high-speed camera platform is built to study the bubble behavior of the subcooled boiling of a water-ethanol mixture in a microchannel. Simultaneous synchronisation of thermodynamic transient characterisation and high speed flow visualisation. The flow in the microchannel can be divided into single-phase convection, isolated bubble, bubbly flow, and slug flow regions. The combination of micro-channel and multi-component coolant along with keeping the subcooled boiling within the bubbly flow region can improve the heat transfer performance. The wall effect in the microchannel will enhance the bubble-induced heat transfer and result in a reduced heat transfer performance under higher inlet velocity conditions. Compared with lower velocity of 0.05 m/s, the bubble departure frequency for higher velocity of 0.15 m/s decreased by a maximum of 2 times in the bubbly flow region. The heat transfer coefficient for the bubbly flow regime is found to be universally proportional to the void fraction for all conditions analysed in this paper. Hence, the manners that are beneficial for void fraction improvement can be utilized to regulate the heat transfer coefficient of the microchannel within the bubbly flow regime.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110091"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to reduce the hazard of the heavy metal chromium, the reduction of Cr from Cr(VI) to Cr(III) for further removal was applied in this study. ZIF-8 modified with Ag was used as the photo-catalyst, and adsorption and degradation were further enhanced by deep penetration through in situ growth of Ag/ZIF-8 in the pores of polyvinylidene fluoride (PVDF) membrane. The composite Ag/ZIF-8/PVDF membrane was characterized by XRD, BET, SEM-EDS, UV–Vis and XPS, and the results proved that the nanoparticles of ZIF-8 and Ag were uniformly distributed inside the membrane pores. The removal efficiency of Cr(VI) was enhanced by 78 % after modification of Ag nanoparticles on the ZIF-8 surface, and further enhanced by 68 % after loading the composite particles (Ag/ZIF-8) into the PVDF membrane. Moreover, the removal mechanism was investigated by free radical trapping experiments, and the results showed that O2·- was the main factor in the photo-catalytic process, followed by ·OH. The results indicated that enhancement of coupled adsorption-degradation process by deep permeation is a feasible approach to improve the heavy metal removal performance due to the dispersive and domain-limiting effects of membrane pores. Ag/ZIF-8/PVDF material is expected to be applied in the field of practical Cr(VI)-containing industrial wastewater treatment.
{"title":"Removal of Cr(VI) by coupled adsorption and photocatalytic degradation based on Ag/ZIF-8/PVDF membrane","authors":"Chunyan Chen , Jiancai Yue , Jian Zhou , Qian Liu , Yaling Tang , Chunlin Chen , Guoqing Xiao","doi":"10.1016/j.cep.2024.110120","DOIUrl":"10.1016/j.cep.2024.110120","url":null,"abstract":"<div><div>In order to reduce the hazard of the heavy metal chromium, the reduction of Cr from Cr(VI) to Cr(III) for further removal was applied in this study. ZIF-8 modified with Ag was used as the photo-catalyst, and adsorption and degradation were further enhanced by deep penetration through in situ growth of Ag/ZIF-8 in the pores of polyvinylidene fluoride (PVDF) membrane. The composite Ag/ZIF-8/PVDF membrane was characterized by XRD, BET, SEM-EDS, UV–Vis and XPS, and the results proved that the nanoparticles of ZIF-8 and Ag were uniformly distributed inside the membrane pores. The removal efficiency of Cr(VI) was enhanced by 78 % after modification of Ag nanoparticles on the ZIF-8 surface, and further enhanced by 68 % after loading the composite particles (Ag/ZIF-8) into the PVDF membrane. Moreover, the removal mechanism was investigated by free radical trapping experiments, and the results showed that O<sub>2</sub>·<sup>-</sup> was the main factor in the photo-catalytic process, followed by ·OH. The results indicated that enhancement of coupled adsorption-degradation process by deep permeation is a feasible approach to improve the heavy metal removal performance due to the dispersive and domain-limiting effects of membrane pores. Ag/ZIF-8/PVDF material is expected to be applied in the field of practical Cr(VI)-containing industrial wastewater treatment.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110120"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110109
Hulusi Delibaş, İbrahim Halil Yılmaz
Fins are widely used thermal elements that help transport heat away from a hot surface by increasing the surface area and volume of cooling fluid that flows through them. The functional material selected for these elements is critical for accomplishing efficient heat removal at a low cost. Fin profile, material properties, surface properties, raw material cost, and manufacturing cost are decisive in selecting competitive materials from a holistic perspective. This study has presented two novel material indices for effectively selecting fin and contact heat sink materials. A guiding methodology has been proposed involving both material cost and applicable manufacturing processes for candidate materials. A cost model is proposed to compare manufacturing processes, and production characteristics for varying fin profiles are also investigated. Results show that although die casting is the most economical process among all processes and can produce almost any fin shape, hot forming processes like extrusion and forging allow implementing fin materials with 90.2−98.1% higher thermal conductivity. Beryllia alloys and aluminum nitrides with relatively higher thermal conductivity, ranging between 60−330 W/m∙°C, are preferable for contact heat sinks.
{"title":"Thermo-economic optimization for the advanced material selection of fins and heat sinks","authors":"Hulusi Delibaş, İbrahim Halil Yılmaz","doi":"10.1016/j.cep.2024.110109","DOIUrl":"10.1016/j.cep.2024.110109","url":null,"abstract":"<div><div>Fins are widely used thermal elements that help transport heat away from a hot surface by increasing the surface area and volume of cooling fluid that flows through them. The functional material selected for these elements is critical for accomplishing efficient heat removal at a low cost. Fin profile, material properties, surface properties, raw material cost, and manufacturing cost are decisive in selecting competitive materials from a holistic perspective. This study has presented two novel material indices for effectively selecting fin and contact heat sink materials. A guiding methodology has been proposed involving both material cost and applicable manufacturing processes for candidate materials. A cost model is proposed to compare manufacturing processes, and production characteristics for varying fin profiles are also investigated. Results show that although die casting is the most economical process among all processes and can produce almost any fin shape, hot forming processes like extrusion and forging allow implementing fin materials with 90.2−98.1% higher thermal conductivity. Beryllia alloys and aluminum nitrides with relatively higher thermal conductivity, ranging between 60−330 W/m∙°C, are preferable for contact heat sinks.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110109"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110088
Yiping Cao , Linghong Tang , Wei Li , Shenguan Xu , Min Zeng , Kai Zhao
The demand for heat transfer in various industries has been growing rapidly in recent years, which creates severe demands on heat exchangers with high efficiency. The development of low-noise level heat exchangers is critical for submarines and other highly stealthy equipment. Based on the flow properties in the shell-side of shell and tube heat exchanger with continuous helical baffles, the fully and confined helical channels with single tube and tube bundles are established in this paper. Computational fluid dynamics and Aero-acoustic theory are combined to examine the heat transfer and flow noise propagation mechanism inside the helical channels. The results show that the helical channel with helix angle β = 40° exhibits the best overall performance for both single tube and tube bundles. This configuration not only achieves higher heat transfer efficiency but also maintains lower sound pressure levels. As the Reynolds number increases, the pressure drops, the Nusselt number and the sound pressure level all increase. The helical flow within the helix channels contributes to improving the heat transfer performance. The heat transfer performance is enhanced by 2.8∼22.0 % compared with the straight channel. Notably, the maximum sound pressure level observed in the helical channel at a helix angle of β = 40°, which registers at 69.22 dB, lies intermediate to the values recorded for the straight channels and other helical channels. The research can not only highlight the low-noise advantages of helical baffles but also offer new design guidance for noise and vibration suppression in heat exchangers.
{"title":"Numerical investigation on the aerodynamic noise and heat transfer characteristics of continuous helical channels with tube bundles","authors":"Yiping Cao , Linghong Tang , Wei Li , Shenguan Xu , Min Zeng , Kai Zhao","doi":"10.1016/j.cep.2024.110088","DOIUrl":"10.1016/j.cep.2024.110088","url":null,"abstract":"<div><div>The demand for heat transfer in various industries has been growing rapidly in recent years, which creates severe demands on heat exchangers with high efficiency. The development of low-noise level heat exchangers is critical for submarines and other highly stealthy equipment. Based on the flow properties in the shell-side of shell and tube heat exchanger with continuous helical baffles, the fully and confined helical channels with single tube and tube bundles are established in this paper. Computational fluid dynamics and Aero-acoustic theory are combined to examine the heat transfer and flow noise propagation mechanism inside the helical channels. The results show that the helical channel with helix angle <em>β</em> = 40° exhibits the best overall performance for both single tube and tube bundles. This configuration not only achieves higher heat transfer efficiency but also maintains lower sound pressure levels. As the Reynolds number increases, the pressure drops, the Nusselt number and the sound pressure level all increase. The helical flow within the helix channels contributes to improving the heat transfer performance. The heat transfer performance is enhanced by 2.8∼22.0 % compared with the straight channel. Notably, the maximum sound pressure level observed in the helical channel at a helix angle of <em>β</em> = 40°, which registers at 69.22 dB, lies intermediate to the values recorded for the straight channels and other helical channels. The research can not only highlight the low-noise advantages of helical baffles but also offer new design guidance for noise and vibration suppression in heat exchangers.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110088"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110090
Muhammad Mujiburohman
Fixed adsorptive distillation (FAD), a hybrid separation method combining distillation and adsorption, was proven to be able to break the azeotropic point and to enhance the product purity of azeotropic solution. FAD consists of two conventional distillation columns, equipped with an inter-bed of adsorbent. To operate a continuous FAD, a pair of adsorbent beds must be utilized in which adsorption operation and adsorbent regeneration are carried out alternately. This work is a parametric study which aims to model and to simulate a continuous FAD with adsorbent regeneration using thermal desorption. The azeotropic solution model used is water-isopropyl alcohol (IPA) with adsorbent of silica. Variable analysis is conducted to derive the equations, to obtain the appropriate design variable/s, and to systematically calculate the state variables. The appropriate design variables are the adsorptive flow (Adf) and the bottom product of Column 2 (B2); while the recycle variable is the distillate of Column 2 (D2). The successful continuous FAD is measured based on the composition of IPA in the feed of Column 2 (xF2) and that in the distillate of Column 2 (xD2); both must be above the azeotropic point. To ensure the successful continuous FAD with a fresh feed of 100 mol/min. (30 % mole IPA), relatively pure water and IPA in both bottoms, and equal flow split of adsorptive-bypass flow (Rf = 1), the adsorptive flow and the flow rate of bottom product of Column 2 are operated at (25.00–107.00) mol/min. and (29.77–30.29) mol/min., respectively.
{"title":"Modeling and simulation of continuous fixed adsorptive distillation with adsorbent regeneration using thermal desorption","authors":"Muhammad Mujiburohman","doi":"10.1016/j.cep.2024.110090","DOIUrl":"10.1016/j.cep.2024.110090","url":null,"abstract":"<div><div>Fixed adsorptive distillation (FAD), a hybrid separation method combining distillation and adsorption, was proven to be able to break the azeotropic point and to enhance the product purity of azeotropic solution. FAD consists of two conventional distillation columns, equipped with an inter-bed of adsorbent. To operate a continuous FAD, a pair of adsorbent beds must be utilized in which adsorption operation and adsorbent regeneration are carried out alternately. This work is a parametric study which aims to model and to simulate a continuous FAD with adsorbent regeneration using thermal desorption. The azeotropic solution model used is water-isopropyl alcohol (IPA) with adsorbent of silica. Variable analysis is conducted to derive the equations, to obtain the appropriate design variable/s, and to systematically calculate the state variables. The appropriate design variables are the adsorptive flow (<em>A<sub>df</sub></em>) and the bottom product of Column 2 (<em>B<sub>2</sub></em>); while the recycle variable is the distillate of Column 2 (<em>D<sub>2</sub></em>). The successful continuous FAD is measured based on the composition of IPA in the feed of Column 2 (<em>x<sub>F2</sub></em>) and that in the distillate of Column 2 (<em>x<sub>D2</sub></em>); both must be above the azeotropic point. To ensure the successful continuous FAD with a fresh feed of 100 mol/min. (30 % mole IPA), relatively pure water and IPA in both bottoms, and equal flow split of adsorptive-bypass flow (<em>R<sub>f</sub></em> = 1), the adsorptive flow and the flow rate of bottom product of Column 2 are operated at (25.00–107.00) mol/min. and (29.77–30.29) mol/min., respectively.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110090"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110136
Zhiqun Yu , Lishan Geng , Zhaoyang Mu , Jiadi Zhou , Bingbing Chen , Yuyu Yang
Mononitration products of N-(4-Methoxyphenyl)acetamide (NMA) are intermediates of various mature products. However, for the nitration of NMA, N-(4-methoxy-2-nitrophenyl)acetamide (2-NMA) and N-(4-methoxy-3-nitrophenyl) acetamide (3-NMA) will be produced at the same time, making it difficult to control the selectivity of single nitration product, and no kinetics study has ever been reported before. To comprehend the high regioselectivity nitration of NMA more deeply, a microfluidic system was developed to evaluate the reaction kinetics of NMA nitration. At first, two different systems for nitration were identified. Then, the kinetics parameters for these two systems were determined. Next, a series of validation experiments were designed to show the accuracy of the kinetic model. In the end, to obtain a controlled selectivity, the effects of reaction temperature, initial concentration and molar ratio were investigated through the model simulation. Under the conditions optimized by the kinetic model, the selectivity for both 2-NMA and 3-NMA could achieve above 99.5 %, but due to the changes in the properties of the reaction solution, it was extremely difficult to achieve in practice. Ultimately, within the feasibility range of the kinetic model, 98.4 % selectivity of 2-NMA and 96.1 % selectivity of 3-NMA were obtained in the microreactor, respectively.
{"title":"Mononitration of N-(4-Methoxyphenyl)acetamide in continuous-flow: Kinetics study and process optimization","authors":"Zhiqun Yu , Lishan Geng , Zhaoyang Mu , Jiadi Zhou , Bingbing Chen , Yuyu Yang","doi":"10.1016/j.cep.2024.110136","DOIUrl":"10.1016/j.cep.2024.110136","url":null,"abstract":"<div><div>Mononitration products of <em>N</em>-(4-Methoxyphenyl)acetamide (<strong>NMA</strong>) are intermediates of various mature products. However, for the nitration of <strong>NMA</strong>, <em>N</em>-(4-methoxy-2-nitrophenyl)acetamide (<strong>2-NMA</strong>) and <em>N</em>-(4-methoxy-3-nitrophenyl) acetamide (<strong>3-NMA</strong>) will be produced at the same time, making it difficult to control the selectivity of single nitration product, and no kinetics study has ever been reported before. To comprehend the high regioselectivity nitration of <strong>NMA</strong> more deeply, a microfluidic system was developed to evaluate the reaction kinetics of <strong>NMA</strong> nitration. At first, two different systems for nitration were identified. Then, the kinetics parameters for these two systems were determined. Next, a series of validation experiments were designed to show the accuracy of the kinetic model. In the end, to obtain a controlled selectivity, the effects of reaction temperature, initial concentration and molar ratio were investigated through the model simulation. Under the conditions optimized by the kinetic model, the selectivity for both <strong>2-NMA</strong> and <strong>3-NMA</strong> could achieve above 99.5 %, but due to the changes in the properties of the reaction solution, it was extremely difficult to achieve in practice. Ultimately, within the feasibility range of the kinetic model, 98.4 % selectivity of <strong>2-NMA</strong> and 96.1 % selectivity of <strong>3-NMA</strong> were obtained in the microreactor, respectively.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"208 ","pages":"Article 110136"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.cep.2024.110141
Piotr Cyganowski , Włodzimierz Tylus , Sebastian Kinas , Piotr Jamróz
Aromatic amines (AAMs) are essential compounds for producing a wide range of industrial and pharmaceutical products. However, traditional synthesis methods using nitroaromatic compounds (NACs) pose environmental and health risks due to byproduct contamination and the carcinogenic nature of NACs. In this context, this study introduces a novel catalyst containing rhenium (Re) active sites. While this approach does not eliminate the carcinogenic risks associated with NACs, it aims to improve process efficiency. The catalyst, synthesized within a styrene-based matrix functionalized with 1,1′-carbonyldiimidazole, combines high affinity for NACs with the catalytic prowess of Re that may be also a tool in achieving process selectivity. Characterization via XPS and HRTEM confirmed the presence of highly dispersed Re species within the polymer matrix. The catalyst demonstrated superior activity in batch hydrogenation of various NACs, achieving high conversion rates. A 3D-printed packed bed reactor (PBR) was then developed for continuous flow-mode reduction of 4-nitrophenol (4-NP), achieving significant processing capacity and highlighting its potential for scalable applications. This innovative approach not only addresses environmental concerns associated with NACs but also enhances the efficiency of AAM production, presenting a viable solution for industrial processes.
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