The purpose of this work is to develop a mass transfer model that incorporates all relevant facto... more The purpose of this work is to develop a mass transfer model that incorporates all relevant factors—migration, diffusion, and convection—to predict ion transfer in electrodialysis cells more completely than conventional models, which neglect convection. As a demonstration of this approach, the study develops a three-dimensional model that incorporates the factor of convection to predict NaCl mass transport through a rectangular electrodialysis cell. The equations used in the model—the complete Navier–Stokes, continuity, and steady-state Nernst–Planck equations—are solved by the finite difference numerical method in the particular control volumes. The equations in the dilute chamber are numerically solved using techniques from computational fluid dynamics (CFD). In order to evaluate the reliability and accuracy of the model, the results are compared with theory as calculated by the Nernst–Planck equation. We discovered that the developed model is capable of predicting the velocity distribution, separation percent, ion concentration distribution, and electrolyte potential in the chamber, with results that closely align with the theory. Additionally, by considering all three contributions, the developed model could predict a detailed distribution of concentration and potential drop in both the x- and y-directions.
One of the main issues facing mankind in this century is the global warming which is induced by t... more One of the main issues facing mankind in this century is the global warming which is induced by the increasing concentration of carbon dioxide and other greenhouse gases in the atmosphere. A promising process for controlling the atmospheric CO2 level is prevention of combustion in flares. In the present work, a novel GTL loop is proposed to convert the natural gas wasted by a gas refinery to higher molecular weight hydrocarbons. The process proposes an alternative method instead of conventional gas-burning flares, aims to minimize CO2 emissions and produce liquid fuel such as gasoline. For this purpose, purged natural gas is converted to synthesis gas in a novel hydrogen-permselective membrane reactor with recycle stream and then it is converted to liquid fuel in Fischer-Tropsch membrane reactor. In this configuration, a loop is constructed by returning and mixing a portion of the product with the original feed through a recycle stream. This approach produces large amounts of higher molecular weight hydrocarbons, hydrogen production and decreases environmental impacts owing to purge gases emission. The simulation results of the aforesaid loop, show decrease in CO2 emission rate with a value of 1/10 to that of flaring with production of 0.018 kgmol/s of hydrogen and more than 90 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value of (about 4 MMscfd) purge gases.
Recently global attempt are focused on replacing gas flaring by environmentally friendly technolog... more Recently global attempt are focused on replacing gas flaring by environmentally friendly technologies, such as gas to liquid (GTL) technology. The main aim of this practice is preventing waste of energy and decreasing the emission of CO2 and other harmful by-product gases. In order to fulfill this goal, improvement of GTL process efficiency seems necessary. For this purpose, in this work the performance of two different configurations is compared in basis of hydrogen component. In both, refinery purge gases are used as a feedstock where enter to reaction side of a hydrogen perm-selective membrane reformer. In the first configuration, steam reformer reactor is located outside the Fischere-Tropsch synthesis loop while in the second one is placed inside the loop. A portion of generated hydrogen in the reformer is permeated through the membrane as a byproduct and the remaining is utilized in FischereTropsch synthesis reactions. The simulation results of the aforementioned loops show that the second configuration is better than the first one of operation. The results of second configuration show 87% hydrogen utilization in FeT reactions and 11% hydrogen production in steam reformer reactions and also 2% hydrogen exit by off gas in separator. Further advantages of this alternative are namely, lessening in CO2 emission rate with a value of 0.8 for the first configuration ones and less than 0.33 to that of flaring, and more than 8430 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value (about 356.5 MMscfd) of purge gases.
Developing a Mechanistic Transport Model for Electrodialysis/Electrodialysis Reversal Process Aza... more Developing a Mechanistic Transport Model for Electrodialysis/Electrodialysis Reversal Process Azadeh Ghorbani *, Leila Karimi, Abbas Ghassemi, Jim Loya Institute for Energy and the Environment New Mexico State University, Las Cruces, NM, USA. *azadeh12@nmsu.edu There is no doubt that the fresh water demand will continue to increases due to the growth of the world’s population and the increase of the worldwide demand on consumer goods. Technologies that were originally developed to desalinate water such as Reverse Osmosis (RO) and Electrodialysis/ Electrodialysis Reversal, ED/EDR, are widely applied to remove contaminants other than salt from freshwater supplies. ED/EDR is an Electrical-driven membrane technology that is effective with salt removal in which ions are transferred through ion exchange membrane. These process would cost less compared to the RO process but no complete model has been presented yet. Therefore, there is a definite need for presenting a model which would incl...
The purpose of this work is to develop a mass transfer model that incorporates all relevant facto... more The purpose of this work is to develop a mass transfer model that incorporates all relevant factors—migration, diffusion, and convection—to predict ion transfer in electrodialysis cells more completely than conventional models, which neglect convection. As a demonstration of this approach, the study develops a three-dimensional model that incorporates the factor of convection to predict NaCl mass transport through a rectangular electrodialysis cell. The equations used in the model—the complete Navier–Stokes, continuity, and steady-state Nernst–Planck equations—are solved by the finite difference numerical method in the particular control volumes. The equations in the dilute chamber are numerically solved using techniques from computational fluid dynamics (CFD). In order to evaluate the reliability and accuracy of the model, the results are compared with theory as calculated by the Nernst–Planck equation. We discovered that the developed model is capable of predicting the velocity distribution, separation percent, ion concentration distribution, and electrolyte potential in the chamber, with results that closely align with the theory. Additionally, by considering all three contributions, the developed model could predict a detailed distribution of concentration and potential drop in both the x- and y-directions.
One of the main issues facing mankind in this century is the global warming which is induced by t... more One of the main issues facing mankind in this century is the global warming which is induced by the increasing concentration of carbon dioxide and other greenhouse gases in the atmosphere. A promising process for controlling the atmospheric CO2 level is prevention of combustion in flares. In the present work, a novel GTL loop is proposed to convert the natural gas wasted by a gas refinery to higher molecular weight hydrocarbons. The process proposes an alternative method instead of conventional gas-burning flares, aims to minimize CO2 emissions and produce liquid fuel such as gasoline. For this purpose, purged natural gas is converted to synthesis gas in a novel hydrogen-permselective membrane reactor with recycle stream and then it is converted to liquid fuel in Fischer-Tropsch membrane reactor. In this configuration, a loop is constructed by returning and mixing a portion of the product with the original feed through a recycle stream. This approach produces large amounts of higher molecular weight hydrocarbons, hydrogen production and decreases environmental impacts owing to purge gases emission. The simulation results of the aforesaid loop, show decrease in CO2 emission rate with a value of 1/10 to that of flaring with production of 0.018 kgmol/s of hydrogen and more than 90 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value of (about 4 MMscfd) purge gases.
Recently global attempt are focused on replacing gas flaring by environmentally friendly technolog... more Recently global attempt are focused on replacing gas flaring by environmentally friendly technologies, such as gas to liquid (GTL) technology. The main aim of this practice is preventing waste of energy and decreasing the emission of CO2 and other harmful by-product gases. In order to fulfill this goal, improvement of GTL process efficiency seems necessary. For this purpose, in this work the performance of two different configurations is compared in basis of hydrogen component. In both, refinery purge gases are used as a feedstock where enter to reaction side of a hydrogen perm-selective membrane reformer. In the first configuration, steam reformer reactor is located outside the Fischere-Tropsch synthesis loop while in the second one is placed inside the loop. A portion of generated hydrogen in the reformer is permeated through the membrane as a byproduct and the remaining is utilized in FischereTropsch synthesis reactions. The simulation results of the aforementioned loops show that the second configuration is better than the first one of operation. The results of second configuration show 87% hydrogen utilization in FeT reactions and 11% hydrogen production in steam reformer reactions and also 2% hydrogen exit by off gas in separator. Further advantages of this alternative are namely, lessening in CO2 emission rate with a value of 0.8 for the first configuration ones and less than 0.33 to that of flaring, and more than 8430 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value (about 356.5 MMscfd) of purge gases.
Developing a Mechanistic Transport Model for Electrodialysis/Electrodialysis Reversal Process Aza... more Developing a Mechanistic Transport Model for Electrodialysis/Electrodialysis Reversal Process Azadeh Ghorbani *, Leila Karimi, Abbas Ghassemi, Jim Loya Institute for Energy and the Environment New Mexico State University, Las Cruces, NM, USA. *azadeh12@nmsu.edu There is no doubt that the fresh water demand will continue to increases due to the growth of the world’s population and the increase of the worldwide demand on consumer goods. Technologies that were originally developed to desalinate water such as Reverse Osmosis (RO) and Electrodialysis/ Electrodialysis Reversal, ED/EDR, are widely applied to remove contaminants other than salt from freshwater supplies. ED/EDR is an Electrical-driven membrane technology that is effective with salt removal in which ions are transferred through ion exchange membrane. These process would cost less compared to the RO process but no complete model has been presented yet. Therefore, there is a definite need for presenting a model which would incl...
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Papers by Azadeh Ghorbani
In this configuration, a loop is constructed by returning and mixing a portion of the product with the
original feed through a recycle stream. This approach produces large amounts of higher molecular
weight hydrocarbons, hydrogen production and decreases environmental impacts owing to purge gases emission. The simulation results of the aforesaid loop, show decrease in CO2 emission rate with a value of 1/10 to that of flaring with production of 0.018 kgmol/s of hydrogen and more than 90 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value of (about 4 MMscfd) purge gases.
In this configuration, a loop is constructed by returning and mixing a portion of the product with the
original feed through a recycle stream. This approach produces large amounts of higher molecular
weight hydrocarbons, hydrogen production and decreases environmental impacts owing to purge gases emission. The simulation results of the aforesaid loop, show decrease in CO2 emission rate with a value of 1/10 to that of flaring with production of 0.018 kgmol/s of hydrogen and more than 90 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value of (about 4 MMscfd) purge gases.