The Experts below are selected from a list of 1410 Experts worldwide ranked by ideXlab platform
Chao Yang - One of the best experts on this subject based on the ideXlab platform.
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visual study on the Interphase Mass Transfer of immiscible liquid liquid system in a stirred tank
Industrial & Engineering Chemistry Research, 2019Co-Authors: Xiaoxia Duan, Chao YangAbstract:A novel experiment is designed to visually study the Interphase Mass Transfer in an immiscible liquid–liquid system using the planar laser-induced fluorescence method combined with the refractive i...
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the Interphase Mass Transfer in liquid liquid systems with marangoni effect
European Physical Journal-special Topics, 2015Co-Authors: Jiayong Chen, Chao YangAbstract:In this paper, we review the related studies on the Interphase Mass Transfer process accompanied with Marangoni effect in liquid-liquid systems. The Marangoni effect is triggered by the local variation of interfacial tension and influenced by many factors, such as the physicochemical properties of the system, the solute concentration and the bulk flow. The onset criterion of the Marangoni effect has been discussed extensively via theoretical analysis and experimental verification, but a unified and universal criterion was still not developed due to the complex system geometry and boundary conditions. When the Marangoni convection occurred, the bulk flow adjacent to the interface was spontaneously disturbed, normally leading to an enhanced Mass Transfer coefficient. Besides, the surface active agent has been found to affect the solute transport across the interface, by either promoting or inhibiting the Marangoni convection according to the nature of additives.
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numerical simulation of the solute induced marangoni effect with the semi lagrangian advection scheme
Chemical Engineering & Technology, 2015Co-Authors: Jie Chen, Zhihui Wang, Chao Yang, Zaisha MaoAbstract:The level set method is combined with the concentration transformation method to solve the Interphase Mass Transfer process. However, the artificial diffusion generated in the Mass Transfer convection term across the interface is inevitable, especially when large shape deformation is encountered at high Reynolds numbers. A semi-Lagrangian advection scheme is introduced to overcome this disadvantage. The methyl isobutyl ketone (MIBK)-acetic acid-water system is adopted to study the unsteady Mass transport process accompanied with the Marangoni effect of a single deformable drop ascending in the infinite continuous phase. The predicted overall Mass Transfer coefficients agree with experimental data very well. The configuration of Marangoni convection is revealed and its effect on the Interphase Mass Transfer process is investigated.
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numerical simulation of the marangoni effect on transient Mass Transfer from single moving deformable drops
Aiche Journal, 2011Co-Authors: Jianfeng Wang, Zhihui Wang, Ping Lu, Chao YangAbstract:A level set approach was adopted in numerical simulation of Interphase Mass Transfer from a deformable drop moving in a continuous immiscible liquid, and the simulation results on Marangoni effect were presented with respect to three experimental runs in the methyl isobutyl ketone-acetic acid-water system. Experiments showed that when the solute concentration was sufficiently high, the Marangoni effect would occur with the Interphase Mass Transfer enhanced. Numerical results indicated that the Mass-Transfer coefficient with Marangoni effect was larger than that without Marangoni effect and stronger Marangoni effect made the drop deform more easily. The predictions were qualitatively in accord with the experimental data. Numerical simulation revealed well the transient flow structure of Marangoni effect. (C) 2011 American Institute of Chemical Engineers AIChE J, 57: 2670-2683, 2011
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experimental investigation of marangoni effect in 1 hexanol water system
Chemical Engineering Science, 2011Co-Authors: Zhihui Wang, Chao Yang, Guangji Zhang, Yumei Yong, Zaisha MaoAbstract:In this work, the interfacial phenomena of a single hanging drop have been observed and captured by a Schlieren optical system. The extraction fractions at different hanging times were determined. For the system without surfactant, the Marangoni effect induced by Interphase Mass Transfer of a solute displays regular convection patterns. The addition of surfactants changed the mode of interfacial instability significantly but in different ways: SDS enhanced the Mass Transfer and Triton X-100 reduced the extraction fraction.
P A M Springer - One of the best experts on this subject based on the ideXlab platform.
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composition trajectories for heterogeneous azeotropic distillation in a bubble cap tray column influence of Mass Transfer
Chemical Engineering Research & Design, 2003Co-Authors: P A M Springer, R Baur, R KrishnaAbstract:The overall objective of this work is to examine the influence of Interphase Mass Transfer on the composition trajectories in heterogeneous azeotropic distillation. Experiments were carried out in a bubble cap distillation column operated at total reflux with the systems: water-ethanol-cyclohexane and water-acetone-toluene. The experiments were carried out in regions of the composition space such that liquid-liquid phase splitting occurred on some of the trays. In order to model the composition trajectories, a rigorous non-equilibrium (NEQ) stage model is developed. The NEQ model incorporates the Maxwell-Stefan diffusion equations to describe the various intraphase Transfers. The developed NEQ model is in good agreement with the experimental results for both experimental systems. In sharp contrast, an equilibrium (EQ) stage model fails even at the qualitative level to model the experiments. For example, for the water-ethanol-cyclohexane system the EQ model anticipates distillation boundary crossing when this does not take place in practice. For the water-acetone-toluene system the EQ model does not anticipate distillation boundary crossing when this phenomena is found in the experiments. It is concluded that for reliable design of azeotropic distillation columns we must take Interphase Mass Transfer effects into account in a rigorous manner.
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influence of Interphase Mass Transfer on the composition trajectories and crossing of boundaries in ternary azeotropic distillation
Separation and Purification Technology, 2002Co-Authors: P A M Springer, R Baur, Rajamani KrishnaAbstract:Abstract This paper examines the influence of Mass Transfer on the composition trajectories in multicomponent azeotropic distillation. Simulations were carried out for three different ternary systems: methanol–isopropanol–water, water–ethanol–acetone, and water–methanol–methylacetate. Two different models were used to calculate the composition trajectories in a tray column: an equilibrium (EQ) stage model and a rigorous nonequilibrium (NEQ) stage model based on the Maxwell–Stefan diffusion equations. The simulations show that the EQ and NEQ model trajectories could follow different composition paths and could end up in completely different corners of the composition space. Furthermore, in all the three case studies the NEQ model trajectory was found to cross the distillation boundary even when the boundary is a straight line. The study has implications for the development of improved separation strategies.
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crossing of the distillation boundary in homogeneous azeotropic distillation influence of Interphase Mass Transfer
Industrial & Engineering Chemistry Research, 2002Co-Authors: P A M Springer, R Baur, B Buttinger, Rajamani KrishnaAbstract:Residue curve maps can be used to predict composition trajectories for packed and trayed distillation columns, provided that vapor and liquid phases are in thermodynamic equilibrium and the column is operating at total reflux. In the case of ternary azeotropic distillations, distillation boundaries divide the composition space into two, or more, regions. It has been mentioned in the literature that distillation boundaries that are straight lines cannot be crossed during actual column operation. The major objective of this paper is to show that Interphase Mass Transfer in ternary azeotropic distillation leads to differences in the component Murphree efficiencies and that such differences can allow even straight-line distillation boundaries to be crossed. Experiments were carried out in a bubble-cap distillation column operated at total reflux. The investigated homogeneous azeotropic system water (1)−ethanol (2)−acetone (3) has a binary minimum-boiling azeotrope for the water−ethanol mixture, which leads to...
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boundary crossing during azeotropic distillation of water ethanol methanol at total reflux influence of Interphase Mass Transfer
Computer-aided chemical engineering, 2002Co-Authors: P A M Springer, Rajamani KrishnaAbstract:Abstract Experiments were carried out in a bubble cap distillation column operated at total reflux with the system: water (1) — ethanol (2) — methanol (3). This system has a binary azeotrope for the water-ethanol mixture, which leads to a slightly curved simple distillation boundary between the azeotrope and pure methanol. For certain starting compositions the measured distillation composition trajectory clearly demonstrate that crossing the distillation boundary is possible. In order to rationalize our experimental results, we develop a rigorous nonequilibrium (NEQ) stage model, incorporating the Maxwell-Stefan diffusion equations to describe Transfer in either fluid phase. The developed NEQ model anticipates the boundary crossing effects and is in excellent agreement with a series of experiments carried out in different composition regions. In sharp contrast, an equilibrium (EQ) stage model fails even at the qualitative level to model the experiments. It is concluded that for reliable design of azeotropic distillation columns we must take Interphase Mass Transfer effects into account in a rigorous manner.
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crossing of boundaries in ternary azeotropic distillation influence of Interphase Mass Transfer
International Communications in Heat and Mass Transfer, 2001Co-Authors: P A M Springer, Rajamani KrishnaAbstract:Abstract This paper examines the influence of Mass Transfer on the composition trajectories in multicomponent azeotropic distillation. Simulations were carried out for five different ternary systems: methanol — iso propanol — water, water — ethanol — acetone, acetone — chloroform — methanol, acetone — chloroform — ethanol, and water — cyclohexane — ethanol. Two different models were used to calculate the composition trajectories in a tray column: an equilibrium (EQ) stage model and a rigorous nonequilibrium (NEQ) stage model based on the Maxwell-Stefan diffusion equations. The simulations show that the EQ and NEQ model trajectories could follow different composition paths and could end up in completely different corners of the composition triangular space. Futhermore, in some of the case studies the NEQ model trajectory was found to cross the distillation boundary even with the feed on the convex side or when the boundary is a straight line. The study has implications for the development of improved separation possibilities.
Rajamani Krishna - One of the best experts on this subject based on the ideXlab platform.
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influence of Interphase Mass Transfer on the composition trajectories and crossing of boundaries in ternary azeotropic distillation
Separation and Purification Technology, 2002Co-Authors: P A M Springer, R Baur, Rajamani KrishnaAbstract:Abstract This paper examines the influence of Mass Transfer on the composition trajectories in multicomponent azeotropic distillation. Simulations were carried out for three different ternary systems: methanol–isopropanol–water, water–ethanol–acetone, and water–methanol–methylacetate. Two different models were used to calculate the composition trajectories in a tray column: an equilibrium (EQ) stage model and a rigorous nonequilibrium (NEQ) stage model based on the Maxwell–Stefan diffusion equations. The simulations show that the EQ and NEQ model trajectories could follow different composition paths and could end up in completely different corners of the composition space. Furthermore, in all the three case studies the NEQ model trajectory was found to cross the distillation boundary even when the boundary is a straight line. The study has implications for the development of improved separation strategies.
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crossing of the distillation boundary in homogeneous azeotropic distillation influence of Interphase Mass Transfer
Industrial & Engineering Chemistry Research, 2002Co-Authors: P A M Springer, R Baur, B Buttinger, Rajamani KrishnaAbstract:Residue curve maps can be used to predict composition trajectories for packed and trayed distillation columns, provided that vapor and liquid phases are in thermodynamic equilibrium and the column is operating at total reflux. In the case of ternary azeotropic distillations, distillation boundaries divide the composition space into two, or more, regions. It has been mentioned in the literature that distillation boundaries that are straight lines cannot be crossed during actual column operation. The major objective of this paper is to show that Interphase Mass Transfer in ternary azeotropic distillation leads to differences in the component Murphree efficiencies and that such differences can allow even straight-line distillation boundaries to be crossed. Experiments were carried out in a bubble-cap distillation column operated at total reflux. The investigated homogeneous azeotropic system water (1)−ethanol (2)−acetone (3) has a binary minimum-boiling azeotrope for the water−ethanol mixture, which leads to...
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boundary crossing during azeotropic distillation of water ethanol methanol at total reflux influence of Interphase Mass Transfer
Computer-aided chemical engineering, 2002Co-Authors: P A M Springer, Rajamani KrishnaAbstract:Abstract Experiments were carried out in a bubble cap distillation column operated at total reflux with the system: water (1) — ethanol (2) — methanol (3). This system has a binary azeotrope for the water-ethanol mixture, which leads to a slightly curved simple distillation boundary between the azeotrope and pure methanol. For certain starting compositions the measured distillation composition trajectory clearly demonstrate that crossing the distillation boundary is possible. In order to rationalize our experimental results, we develop a rigorous nonequilibrium (NEQ) stage model, incorporating the Maxwell-Stefan diffusion equations to describe Transfer in either fluid phase. The developed NEQ model anticipates the boundary crossing effects and is in excellent agreement with a series of experiments carried out in different composition regions. In sharp contrast, an equilibrium (EQ) stage model fails even at the qualitative level to model the experiments. It is concluded that for reliable design of azeotropic distillation columns we must take Interphase Mass Transfer effects into account in a rigorous manner.
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crossing of boundaries in ternary azeotropic distillation influence of Interphase Mass Transfer
International Communications in Heat and Mass Transfer, 2001Co-Authors: P A M Springer, Rajamani KrishnaAbstract:Abstract This paper examines the influence of Mass Transfer on the composition trajectories in multicomponent azeotropic distillation. Simulations were carried out for five different ternary systems: methanol — iso propanol — water, water — ethanol — acetone, acetone — chloroform — methanol, acetone — chloroform — ethanol, and water — cyclohexane — ethanol. Two different models were used to calculate the composition trajectories in a tray column: an equilibrium (EQ) stage model and a rigorous nonequilibrium (NEQ) stage model based on the Maxwell-Stefan diffusion equations. The simulations show that the EQ and NEQ model trajectories could follow different composition paths and could end up in completely different corners of the composition triangular space. Futhermore, in some of the case studies the NEQ model trajectory was found to cross the distillation boundary even with the feed on the convex side or when the boundary is a straight line. The study has implications for the development of improved separation possibilities.
Zaisha Mao - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of the solute induced marangoni effect with the semi lagrangian advection scheme
Chemical Engineering & Technology, 2015Co-Authors: Jie Chen, Zhihui Wang, Chao Yang, Zaisha MaoAbstract:The level set method is combined with the concentration transformation method to solve the Interphase Mass Transfer process. However, the artificial diffusion generated in the Mass Transfer convection term across the interface is inevitable, especially when large shape deformation is encountered at high Reynolds numbers. A semi-Lagrangian advection scheme is introduced to overcome this disadvantage. The methyl isobutyl ketone (MIBK)-acetic acid-water system is adopted to study the unsteady Mass transport process accompanied with the Marangoni effect of a single deformable drop ascending in the infinite continuous phase. The predicted overall Mass Transfer coefficients agree with experimental data very well. The configuration of Marangoni convection is revealed and its effect on the Interphase Mass Transfer process is investigated.
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experimental investigation of marangoni effect in 1 hexanol water system
Chemical Engineering Science, 2011Co-Authors: Zhihui Wang, Chao Yang, Guangji Zhang, Yumei Yong, Zaisha MaoAbstract:In this work, the interfacial phenomena of a single hanging drop have been observed and captured by a Schlieren optical system. The extraction fractions at different hanging times were determined. For the system without surfactant, the Marangoni effect induced by Interphase Mass Transfer of a solute displays regular convection patterns. The addition of surfactants changed the mode of interfacial instability significantly but in different ways: SDS enhanced the Mass Transfer and Triton X-100 reduced the extraction fraction.
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numerical simulation of marangoni effects of single drops induced by Interphase Mass Transfer in liquid liquid extraction systems by the level set method
Science China-chemistry, 2008Co-Authors: Jianfeng Wang, Chao Yang, Zaisha MaoAbstract:The mathematical model of Mass Transfer-induced Marangoni effect is formulated. The drop surface evolution is captured by the level set method, in which the interface is represented by the embedded set of zero level of a scalar distance function defined in the whole computational domain. Numerical simulation of the Marangoni effect induced by Interphase Mass Transfer to/from deformable single drops in unsteady motion in liquid-liquid extraction systems is performed in a Eulerian axisymmetric reference frame. The occurrence and development of the Marangoni effect are simulated, and the results are in good agreement with the classical theoretical analysis and previous simulation.
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Numerical Simulation of the Marangoni Effect with Interphase Mass Transfer Between Two Planar Liquid Layers
Chinese Journal of Chemical Engineering, 2008Co-Authors: Zaisha Mao, Guangji Zhang, Chao YangAbstract:The Marangoni effect induced by Mass Transfer at the interface between two immiscible liquids displays important influence on laboratory and industrial operation of solvent extraction. A systematic numerical study of the two-dimensional Marangoni effect in a two liquid layer system was conducted. The linear relationship of the interfacial tension versus the solute concentration was incorporated into a mathematical model accounting for liquid flow and Mass Transfer in both phases. The typical cases analyzed by Sternling & Scriven (AIChE J., 1959) using the linear instability theory were simulated by the finite difference method and good agreement between the theory and the numerical simulation was observed. The simulation suggests that the Marangoni convection needs certain time to develop sufficiently in strength and scale to enhance the Interphase Mass Transfer, the Marangoni effect is dynamic and transient, and remains at some stabilized level as long as the Mass Transfer driving force is kept constant. When certain level of shear is imposed at the interface as in most cases of practical significance, the Marangoni effect is suppressed slightly but progressively as the shear is increased gradually. The present two-dimensional simulation of the Marangoni effect provides some insight into the underlying mechanism and also the basis for further theoretical study of the three-dimensional Marangoni effect in the real world and in chemical engineering applications.
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the resistance of Interphase Mass Transfer in colloidal liquid aphron systems
Chemical Engineering Science, 2007Co-Authors: Zaisha MaoAbstract:Abstract Colloidal liquid aphrons (CLAs) provide very large interfacial area and thus could enhance Interphase Mass Transfer in multiphase processes. This work characterized the Mass Transfer behavior of CLAs during Mass Transfer of benzoic acid from cyclohexane in CLAs to water in a small stirred vessel. From experimental data the overall Mass Transfer coefficient K L of the surfactant-stabilized CLAs was determined. The influence of stirring speed and concentration of surfactant used for formulating CLAs on K L was investigated. The experimental results show that surfactant adsorbed on the interface of CLAs influences greatly the value of K L , and when the surfactant concentration is below its CMC, the overall CLAs Mass Transfer coefficient K L (mainly varying with the interfacial Mass Transfer resistance) could be fitted to the following expression: K L = H 1 + H 2 ln [ C + H 3 ] . When the surfactant concentration is above its CMC, it is found that the influence of surfactant on diffusion resistance was dependent on its type. For the non-ionic surfactant, the increase of surfactant concentration has little influence on diffusion resistance. However, for the ionic surfactant, the overall CLAs Mass Transfer coefficient K L (mainly varying with the diffusion resistance) decreases approximately in a linear way as the concentration of ionic surfactant is increased. These correlations represent the experimental data satisfactorily.
Jiayong Chen - One of the best experts on this subject based on the ideXlab platform.
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the Interphase Mass Transfer in liquid liquid systems with marangoni effect
European Physical Journal-special Topics, 2015Co-Authors: Jiayong Chen, Chao YangAbstract:In this paper, we review the related studies on the Interphase Mass Transfer process accompanied with Marangoni effect in liquid-liquid systems. The Marangoni effect is triggered by the local variation of interfacial tension and influenced by many factors, such as the physicochemical properties of the system, the solute concentration and the bulk flow. The onset criterion of the Marangoni effect has been discussed extensively via theoretical analysis and experimental verification, but a unified and universal criterion was still not developed due to the complex system geometry and boundary conditions. When the Marangoni convection occurred, the bulk flow adjacent to the interface was spontaneously disturbed, normally leading to an enhanced Mass Transfer coefficient. Besides, the surface active agent has been found to affect the solute transport across the interface, by either promoting or inhibiting the Marangoni convection according to the nature of additives.
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numerical simulation of the marangoni effect on Mass Transfer to single slowly moving drops in the liquid liquid system
Chemical Engineering Science, 2004Co-Authors: Jiayong ChenAbstract:The Marangoni effect is a frequently observed phenomenon of enhancement of Interphase Mass Transfer in liquid-liquid systems. Such an effect, originating front the hydrodynamic instability induced by surface tension sensitivity to surface concentration of Transferred solute, is mathematically formulated and numerically simulated for slowly moving single spherical drops in an axisymmetric boundary-fitted coordinate system by solving coupled fluid flow and solute Mass Transfer equations. Numerical simulation demonstrates the occurrence of the Marangoni effect under typical conditions in liquid-liquid systems, and is in reasonable agreement with the classic theoretical analysis. Sufficient spatial and temporal resolution in simulation reveals the multi-scale interaction of the drop-scale Marangoni effect with the sub-drop-scale local interfacial convection. The effect of solute Transfer direction, Peclet number, surface tension sensitivity to solute concentration, and level of random perturbation on surface concentration are investigated numerically. It is shown that the Marangoni effect occurs in the middle stage of a transient Interphase Mass Transfer process, and the Marangoni convection at the interface does not necessarily results in the Marangoni effect of Mass Transfer enhancement. Besides, the Marangoni effect occurs only when the surface tension sensitivity to the solute concentration variation is above certain critical level. The present axisymmetric simulation of the Marangoni effect provides necessary basis for further work on three-dimensional numerical analysis. (C) 2004 Elsevier Ltd. All rights reserved.
