توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱MODELING AND SIMULATION OF CO2 SEPARATION FROM FLUE GAS USING HOLLOW FIBER MEMBRANE CONTACTORS
اطلاعات انتشار: دوازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۲
A comprehensive 2D mathematical model was developed to study separation of CO2 from flue
gas in hollow fiber membrane contactors. The model was based on “non–wetted mode” in which the gas
mixture filled the membrane pores. Laminar parabolic velocity profile was used for the liquid flow in the
tube side; whereas, the gas flow in the shell side was characterized by Happel’s free surface model. Axial and radial diffusion inside the shell, through the membrane, and within the tube side of the contactor were considered in the model. The equations of model were solved by numerical method based on finite
element method (FEM). The simulation results were compared with the experimental data reported by S.Yan et al. [2007]. They reported the experimental results for the separation of CO2 from flue gas by aqueous solutions using polypropylene membrane contactor. The simulation results were in good agreement with the experimental results for different values of gas and liquid flow rates.<\div>

۲NUMERICAL SIMULATION OF MASS TRANSFER IN GASLIQUID HOLLOW FIBER MEMBRANE CONTACTORS
اطلاعات انتشار: دوازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۲
Hollow fiber membrane contactors have attracted the attention of many researchers as a new means for gas separation. This study presents a numerical simulation using computational fluid dynamics (CFD) of momentum and mass transfer in a hollow fiber membrane contactor for laminar flow conditions. The velocity and concentration profiles of component A are obtained by resolution of the Navier–Stokes and convection–diffusion equations. The influence of various process parameters on mass transfer is investigated. The simulation results for the physical absorption of CO2 in water indicated that the removal rate of CO2 increased with increasing liquid velocity in the shell side. On the other hand, increasing temperature and gas velocity in the tube side seemed to have an opposite effect.<\div>

۳NUMERICAL SIMULATION OF MASS TRANSFER IN POROCRITICAL EXTRACTION FOR LAMINAR FLOW CONDITIONS
اطلاعات انتشار: دوازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۱
In this study is presented a general methodology to predict the performance of a continuous near–critical fluid extraction process to remove compounds from aqueous solutions using hollow fiber membrane contactors. A comprehensive 2D mathematical model was developed to study Porocritical extraction process. The system studied in this work is a membrane based extractor of ethanol and
acetone from aqueous solutions using near–critical CO2. Predictions of extraction percentages obtained by simulations have been compared to the experimental values reported by Bothun et al. [2003]. Simulations of extraction percentage of ethanol and acetone show an average difference of 9.3% and 6.5% with the experimental data, respectively. More accurate predictions of the extraction of acetone
could be explained by a better estimation of the transport properties in the aqueous phase that controls the extraction of this solute.<\div>

۴Numerical simulation of organic compounds separation from water in membrane using finite element method
نویسنده(ها): ، ،
اطلاعات انتشار: همایش ملی مهندسی شیمی، سال
تعداد صفحات: ۱۰
This paper presents mathematical modeling and numerical simulation using computational fluid dynamics (CFD) of mass transfer for caffeine extraction process carried out in a hollow fiber membrane contactor (HFMC). Simulations were based on solving the conservation equations for solute (caffeine) in the membrane contactor. Simulations were performed for extraction of caffeine by subcritical carbon dioxide in a three–fiber module. Finite element method (FEM) was used for solving differential equations. Simulation results compared with the experimental data obtained from literature to validate mass transfer model. Simulation results showed the average deviation of 13% for extraction efficiency with experimental data. Effect of membrane physical properties on the extraction of caffeine investigated in order to estimate optimum conditions. Simulations indicated that membrane parameters greatly affect the extraction efficiency of caffeine.<\div>

۵Hydrodynamic Investigation on the Solvent Extraction of Copper by means of Membrane Contactors Using Computational Fluid Dynamics (CFD)
اطلاعات انتشار: سومین کنفرانس ملی کاربرد CFD در صنایع شیمیایی، سال
تعداد صفحات: ۱۰
Extraction of heavy metals by membrane contactors was theoretically investigated in this study. As a case study, extraction of Cu2+ with a kerosene solution of di(2–ethylhexyl) phosphoric acid (D2EHPA) was studied. Simulations were performed using computational fluid dynamics (CFD) of mass and momentum transfer in all subdomains of a circular membrane contactor. The membrane contactor consists of three sections: lumen, membrane and shell side. Conservation equations were derived for Cu2+ in the membrane contactor and were solved numerically based on finite element method (FEM). The distribution profiles of velocity, concentration, and pressure were obtained for the solute. Simulation results showed an extraction efficiency of 85.8% for Cu2+ while pressure drop is not appreciable along the membrane contactor. Furthermore, results of this study revealed that CFD is a viable tool for the simulation of solvent extraction process via membrane contactors.<\div>

۶Modeling and Numerical Simulation of Ammonia Stripping from Industrial Wastewater Streams
اطلاعات انتشار: سومین کنفرانس ملی کاربرد CFD در صنایع شیمیایی، سال
تعداد صفحات: ۸
Ammonia removal from water was studied experimentally and theoretically by means of a hollow–fiber membrane contactor (HFMC). Aqueous solution of NH3 flowed as feed in the lumen side of membrane contactor while sulfuric acid was used as stripper in the shell side. An unsteady state and 2D mathematical model was developed to study ammonia stripping in the HFMC. The model was implemented in linked MATLAB–COMSOL Multiphysics. COMSOL software was applied to solve the model equations for the contactor while MATLAB software was employed to consider changes in the feed tank’s concentrations. Modeling predictions were then validated with the experimental data and were found to be in good agreement.<\div>

۷Simulation of CO2 Absorption in Hollow–Fiber Membrane Contactors for Wetting and Non–wetting Modes
اطلاعات انتشار: سومین کنفرانس ملی کاربرد CFD در صنایع شیمیایی، سال
تعداد صفحات: ۷
This study deals with absorption of CO2 in hollow–fiber membrane contactors (HFMCs). Simulations were performed to study CO2 transport through HFMCs. The simulations were performed via CFD techniques based on finite element method (FEM). Simulation results were validated with the experimental data for CO2 absorption using amine aqueous solutions. The simulation results were in consistent with the experimental data. Six liquid absorbents including aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), N–methyldiethanolamine (MDEA), 2–amino–2–methyl–1–propanol (AMP), sodium hydroxide (NaOH) and potassium glycinate (PG) were compared for absorption of CO2. The simulation results showed that the removal of CO2 using aqueous solution of PG was the highest among the other absorbents.<\div>

۸Hollow–Fiber Membrane Contactors; Promising Equipments for the Solvent Extraction of Copper
اطلاعات انتشار: اولین همایش ملی مس، سال
تعداد صفحات: ۱۱
Solvent extraction of copper by means of hollow–fiber membrane contactors was investigated in this study. Extraction of copper is conventionally carried out using mixer–settlers. These contactors have some disadvantages such as consumption of high energy, dispersion of two phases and high operating costs. Membrane contactors can obviate the need for conventional contactors. The most favorable module used as membrane contactor is hollow–fiber module. These modules provide high surface area per contact volume. A known interface can be established between aqueous and organic phases for the purpose of mass transfer and extraction. Equilibrium is established at the aqueous–organic interface and depends on the hydrophobicity or hydrophilicity of the membrane. Investigations on copper extraction revealed that these contactors can be used as a new device for the extraction of copper. Some authors have studied the extraction of Cu2+ with a kerosene solution of di(2–ethylhexyl) phosphoric acid (D2EHPA) using hollow–fiber membrane contactors. The provided simulations have been conducted by computational fluid dynamics of mass and momentum transfer in all subdomains of the membrane contactor. The results demonstrate the capability of membrane contactors as efficient devices in the extraction of copper which can provide complete copper recovery.<\div>

۹Modeling and simulation of mass transfer of molybdenum in membrane contactors
اطلاعات انتشار: چهاردهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۴
Mathematical modeling and simulation of mass transfer of molybdenum in hollow–fiber membrane contactor by 2– ethylhexyl phsphonic acid mono–2– ethylhexyl ester (PC–88A) asextractant was studied in this paper. The modeling is based on hydrophobic membranes in which the organic phase filled the pores of porous membrane for countercurrent liquid–liquid contact.Radial and axial diffusions in all subdomains of contactor considered in the model. Computationalfluid dynamics (CFD) of mass and momentum were used to solve the model equations. The simulations scoped to obtain the distribution of molybdenum concentration in the extractionprocess. The modeling findings revealed that as the aqueous phase flows through the tube side, it moves toward the membrane due to the concentration gradient, and then it is extracted by the moving solvent containing extractant and diluent. It is also indicated that at the inlet of tube sidethe total flux is highest because the concentration gradient is highest<\div>
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