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mass-transfer
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Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; 2019 ; 01496395 (ISSN) ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Simulation of methanol carbonylation reactor in acetic acid production plant: selection of an appropriate correlation for mass transfer coefficients
, Article International Journal of Chemical Reactor Engineering ; Volume 17, Issue 4 , 2019 ; 15426580 (ISSN) ; Tourani, S ; Khorasheh, F ; Sharif University of Technology
De Gruyter
2019
Abstract
This paper deals with mathematical modeling and simulation of methanol carbonylation reactor in acetic acid production plant that consisted of a continuous stirred tank reactor (CSTR), a flash drum, a Joule-Thomson valve, and a condenser. The model was based on material and energy balances that considered liquid-gas mass transfer, thermodynamics, and reactor hydrodynamics. The most important aspect of the model was the selection of an appropriate correlation for prediction of mass transfer coefficient. Several correlations were examined and comparison of the model results with plant data indicated that the correlation reported by Lemoine was most appropriate. The simulation results were...
Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; Volume 55, Issue 17 , 2020 , Pages 3140-3150 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Bellwether Publishing, Ltd
2020
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Mass transfer during drop formation on the nozzle: New flow expansion model
, Article AIChE Journal ; Volume 52, Issue 3 , 2006 , Pages 895-910 ; 00011541 (ISSN) ; Bastani, D ; Taeibi Rahni, M ; Sharif University of Technology
2006
Abstract
An attempt was made to introduce a new approach for evaluating mass transfer during drop formation via definition of a parameter related to the extent of the convective mixing within the growing drop. For this purpose it was assumed that the entrance of the dispersed flow into the growing drop from the nozzle is analogous to the entrance of the flow from a smaller channel to a larger one. This transfer mechanism has been dubbed the "flow expansion." A global time-dependent Reynolds number of growing drop (Regd) was defined based on the equivalent diameter of growing drop as a length scale and also on a velocity scale, which is obtained using this flow expansion assumption. The results show...
Interaction of micropolar fluid structure with the porous media in the flow due to a rotating cone
, Article Alexandria Engineering Journal ; Volume 60, Issue 1 , 2021 , Pages 1249-1257 ; 11100168 (ISSN) ; Ali, K ; Bashir, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
A model of heat and mass transfer of two dimensional MHD micropolar fluid over a cone is constructed. Similarity transformation is adopted for the conversion of partial differential equations into ordinary differential equations have been linearized by employing the Newton's linearization technique and then new sets of equations are discretized using the finite difference method. The impact of non-dimensional parameters is further analyzed and the numerical results for profiles of velocity, temperature and concentration are expressed graphically and the results are discussed in detail. For the higher values of Dufour number, temperature field is enhanced graphically but show the opposite...
Interaction of micropolar fluid structure with the porous media in the flow due to a rotating cone
, Article Alexandria Engineering Journal ; Volume 60, Issue 1 , 2021 , Pages 1249-1257 ; 11100168 (ISSN) ; Ali, K ; Bashir, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
A model of heat and mass transfer of two dimensional MHD micropolar fluid over a cone is constructed. Similarity transformation is adopted for the conversion of partial differential equations into ordinary differential equations have been linearized by employing the Newton's linearization technique and then new sets of equations are discretized using the finite difference method. The impact of non-dimensional parameters is further analyzed and the numerical results for profiles of velocity, temperature and concentration are expressed graphically and the results are discussed in detail. For the higher values of Dufour number, temperature field is enhanced graphically but show the opposite...
Mass Transfer Modeling while Formation of Liquid Jet to another Liquid
, M.Sc. Thesis Sharif University of Technology ; Bastani, Darioush (Supervisor)
Abstract
Liquid-liquid extraction is one of most important processes in chemical industries. So determination of operating condition effects is very critical. In this thesis we modeled concentration profile in the jet via mathematical equations and compare with experimental data. The major problem in concentration profile and solving equations is lack of knowledge in velocity profile within the jet was formed. Therefore, different flow models such as piston flow model, parabolic flow model, vortex flow model and a cone flow model was used and terminal concentrations inside the jet compared with laboratory values. Results shows the most accurate model to predict the flow concentration along the...
Experimental and CFD Study of Physical Properties Effect on Hydrodynamic and Mass Transfer Coefficient of Single Drops
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor)
Abstract
In present study, it is tried to investigate the effect of physical properties on hydrodynamic and overall mass transfer coefficient of single drops using different experiments and then simulation of drop motion with OpenFOAM software version 1.7.1. the systems were choosen are toluene/acetone/water and n-butanol/succinic acid/water which their interfacial tensions are 36 and 1.6 mN/m respectively. Various type of nozzles have been used for produce of 1.5, 2, 3 and 4 millimeter drops. The results show that in absence of solute component, the rising velocity of toluene drops in each size is higher than rising velocity of butanol drops inside the water between 25 to 75 percent. But with...
Study on The Influence of Nanoparticles and Magnetic Field on The Liquid-Liquid Mass Transfer Coefficients
,
M.Sc. Thesis
Sharif University of Technology
;
Molaei Dehkordi, Asghar
(Supervisor)
Abstract
Magnetite (Fe3O4) nanoparticles were synthesized and coated with Oleic Acid using the co-precipitation method. The particles were characterized using DLS, FT-IR, SEM, XRD, VSM and UV-Vis spectrophotometry analysis. The mean size of particles was 28.8 nm and the FT-IR analysis indicated that Oleic Acid was coated suitably on the nanoparticles. The vsm test indicated no hysteresis loop for the particles, defining the superparamagnetism of them. A nanofluid containing nanoparticles in 5wt% Acetic Acid in Toluene as the base fliud was prepared. The stability of this nanofluid was determined using UV-Vis spectrophotometry to be less more then 95% in the first two hours. This nanofluid is used as...
Experimental Investigation of Mass Transfer by Droplet Using Image Processing
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Afshin, Hossein ($item.subfieldsMap.e)
Abstract
Wide and varied aspects of droplet motion due to its increasing application in various fields has attracted much attention. Analysis of mass transfer from the liquid drop into the other fluid, such as complex and intriguing problems in fluid mechanics, which is very important. Many experimental and numerical studies have been carried out in this case that the evelopment of laboratory equipment and software, are rapidly growing.
In this study, given the importance of this issue, experimental study on mass transfer in fluid systems solution droplet liquid - liquid extraction, have been considered. Different methods have been discussed to date. In the present study, using image processing...
In this study, given the importance of this issue, experimental study on mass transfer in fluid systems solution droplet liquid - liquid extraction, have been considered. Different methods have been discussed to date. In the present study, using image processing...
Study of the Effect of Presence of Nano- Particles on the Mass Transfer and Hydrodynamics of Drops
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Goodarznia, Iraj (Supervisor)
Abstract
Regarding to the effect of nanoparticles on mass transfer and hydrodynamics characteristics, limited number of studiesavailableinthe literature.In this work, mass transfer performanceand hydrodynamic characteristics nanofluidshavebeeninvestigated in the liquid−liquid extraction process. The chemical system of toluene-acetic acid-water was used, and two Extraction columnswith diameter of 10cm and height of 55cm and 6 cm were designed. The drops were organic nanofluids containing silica nano-particles and carbon nano-tubes.Synthesized silica nanoparticles by sol-gel methods, were modified with Triethoxyoctylsilane and Polydimethylsiloxane as well as Carbon nano-tubes were modified with dodecyl...
Modeling and simulation of desiccant wheel for air conditioning
, Article Energy and Buildings ; Volume 38, Issue 10 , 2006 , Pages 1230-1239 ; 03787788 (ISSN) ; van Paassen, D ; Saidi, M. H ; Sharif University of Technology
2006
Abstract
This paper presents the modeling of a desiccant wheel used for dehumidifying the ventilation air of an air-conditioning system. The simulation of the combined heat and mass transfer processes that occur in a solid desiccant wheel is carried out with MATLAB Simulink. Using the numerical method, the performance of an adiabatic rotary dehumidifier is parametrically studied, and the optimal rotational speed is determined by examining the outlet adsorption-side humidity profiles. The solutions of the simulation at different conditions used in air dehumidifier have been investigated according to the previous published studies. The model is validated through comparison the simulated results with...
A computational fluid dynamics (CFD) approach to modeling of pervaporation in thin membrane channels
, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Shayegh, M ; Azad, R. R ; Sharif University of Technology
2006
Abstract
A comprehensive model for pervaporation in thin membrane channels was developed to study the effect of changing temperature and concentration on mass flux. This model consists of momentum, energy and species mass balances along and across the membrane in the flow channel. A computational fluid dynamics (CFD) code was written in C++ programming language to solve the coupled non-linear transport equations in the channel by finite volume method. The Semi-Implicit Pressure Link Equation (SIMPLE) CFD algorithm is used to modify the dependent variables in each of the iterations. The effect of variation of temperature and concentration on transport and thermodynamic properties were considered by...
A new approach to heat and mass transfer in a rotary dehumidifier: Modeling and simulation
, Article 2005 ASME Fluids Engineering Division Summer Conference, Houston, TX, 19 June 2005 through 23 June 2005 ; Volume 1 PART B , 2005 , Pages 1049-1054 ; 0791841987 (ISBN); 9780791841983 (ISBN) ; Van Paassen, D ; Saidi, M. H ; Sharif University of Technology
2005
Abstract
In this paper the analytical and simulation modelling of the combined heat and mass transfer processes that occur in a solid desiccant wheel is carried out. Using the numerical method, the performance of an adiabatic rotary dehumidifier is parametrically studied, and the optimal rotational speed is determined by examining the outlet adsorption-side humidity profiles. An approach to compare the solutions for different conditions used in air dehumidifier has been investigated according to the previous published studies. Comparing the simulated results with the published actual values of an experimental work substantiates the validity of model. The model accuracy with respect to the key...
Comparison of a new numerical model with the published data for enthalpy wheel and air dehumidifier: Study of optimum speed and wall effects
, Article 2005 ASME Summer Heat Transfer Conference, HT 2005, San Francisco, CA, 17 July 2005 through 22 July 2005 ; Volume 4 , 2005 , Pages 331-339 ; 0791847314 (ISBN); 9780791847312 (ISBN) ; Van Paassen, D ; Saidi, M. H ; Sharif University of Technology
2005
Abstract
In this paper the analytical and simulation modelling of the combined heat and mass transfer processes that occur in a solid desiccant wheel is carried out. Using the numerical method, the performance of adiabatic rotary dehumidifier and enthalpy wheels are parametrically studied, and the optimal rotational speed is determined by examining the outlet adsorption-side humidity profiles. A comparison of solutions for different conditions used in the air dehumidifier has been investigated according to the previously published studies. These approaches have been developed for enthalpy wheels. The simulated results have been compared with the published actual values of an experimental work. This...
The influence of nanoparticles on hydrodynamic characteristics and mass transfer performance in a pulsed liquid-liquid extraction column
, Article Chemical Engineering and Processing: Process Intensification ; Volume 50, Issue 11-12 , 2011 , Pages 1198-1206 ; 02552701 (ISSN) ; Khoobi, N ; Mozdianfard, M. R ; Bahmanyar, H ; Sharif University of Technology
Abstract
With respect to the influence of nanoparticles on mass transfer characteristics, limited number of studies available in the literature, deal primarily with gas-liquid systems. In this work, mass transfer performance and hydrodynamic characteristics including static and dynamic dispersed phase hold-ups of nanofluids have been investigated for pulsed liquid-liquid extraction column (PLLEC). The nanofluids used were prepared by dispersing SiO2 nanoparticles of 0.01, 0.05 and 0.1 volume percent with two different hydrophobicities in kerosene as base fluid using ultrasonication. UV-vis spectrophotometer was also used for evaluation of the nanofluids stability. The results were compared with...
Numerical modeling of incline plate LiBr absorber
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 47, Issue 3 , November , 2011 , Pages 259-267 ; 09477411 (ISSN) ; Farhanieh, B ; Sharif University of Technology
2011
Abstract
Among major components of LiBr-H 2O absorption chillers is the absorber, which has a direct effect on the chillier size and whose characteristics have significant effects on the overall efficiency of absorption machines. In this article, heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled incline plate absorber in the Reynolds number range of 5
A numerical study on the absorption of water vapor into a film of aqueous LiBr falling along a vertical plate
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 46, Issue 2 , 2009 , Pages 197-207 ; 09477411 (ISSN) ; Farhanieh, B ; Sharif University of Technology
Abstract
Absorber is an important component in absorption machines and its characteristics have significant effects on the overall efficiency of absorption machines. This article reports a model of simultaneous heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water - cooled vertical plate absorber in the Reynolds number range of 5 < Re < 150. The boundary layer assumptions were used for the transport of mass, momentum and energy equations and the fully implicit finite difference method was employed to solve the governing equations in the film flow. Dependence of lithium bromide aqueous properties to the temperature and concentration and film...
The level set modeling of droplet dynamic in fluid-fluid interaction
, Article 39th AIAA Fluid Dynamics Conference, 22 June 2009 through 25 June 2009, San Antonio, TX ; 2009 ; 9781563479755 (ISBN) ; Mazaheri, I ; Dehkordi, A. M ; Schneider, G. E ; Sharif University of Technology
Abstract
In this work, we present a level set method to simulate steady and unsteady mass transfer from a single droplet moving in a second phase fluid under buoyant force. We initially use level set to determine the interface between the two phases, where the shape of drop forms. Next, we extend this method to solve a unique mass transfer equation for the entire solution domain without considering the discontinuity appeared at the interface. We use a finite element method incorporated with the characteristic-based split (CBS) algorithm to implement axi-symmetric mass transfer equations on a stationary Eulerian grid. Of course, the convection-diffusion modeling of mass transfer is different from the...
Reactive absorption in packed bed columns in the presence of magnetic nanoparticles and magnetic field: Modeling and simulation
, Article Journal of Industrial and Engineering Chemistry ; Volume 45 , 2017 , Pages 131-144 ; 1226086X (ISSN) ; Molaei Dehkordi, A ; Sharif University of Technology
Korean Society of Industrial Engineering Chemistry
2017
Abstract
In this article, the influences of ferrofluid and magnetic field on the reactive absorption in packed-bed contactors have been investigated. Because of importance of carbon dioxide emission as a global concern, absorption of carbon dioxide was chosen to investigate these effects. In this regard, multitube approach was applied to model the contactor. The simulation results were validated against experimental data reported in the literature in the absence of nanoparticles and magnetic field and good agreement was obtained. Moreover, influences of various operating conditions on the contactor performance were investigated. It was found that for 3.4 vol.% of magnetic nanoparticles (MNPs), the...