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Investigation of Operating Parameters for Thorium Adsorption from Wastewater by Using of Radiated Grafting Polymeric Adsorbents in Packed Bed Column
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohamad (Supervisor) ; Torab Mostaedi, Meysam (Supervisor) ; Asadollahzadeh, Mehdi (Co-Supervisor) ; Torkaman, Rezvan (Co-Supervisor)
Abstract
Today, the pollution of heavy metals in wastewater and surface waters, which is a global environmental problem, has increased with the expansion of various industrial activities. Heavy metals cause serious health problems due to their accumulation in human and animal tissues. Thorium, is a radioactive element with an atomic number of 90 that is widely used in the optics, aerospace, metallurgy and chemical industries, in the manufacture of high-strength alloys, in UV photocells, and especially in the nuclear industry. The primary sources of radioactive wastewater include nuclear power plants, nuclear energy industry research centers, medical institutions, industrial production, universities,...
Investigation of Sulfate Reducing Bacteria for Treatment of Wastewaters Polluted by Heavy Metals
, M.Sc. Thesis Sharif University of Technology ; Kariminia Hamedani, Hamid Reza (Supervisor) ; Borghei, Mehdi (Supervisor)
Abstract
The main objective of this research was to evaluate the application of a new strain of Brevundimonas naejangsanensis which is newly identified sulfate-reducing bacteria (SRB), in chromium(VI) removal in contaminated wastewater. A laboratory scale packed bed reactor (PBR) was fabricated and operated to study the bacteria’s feasibility on chromium(VI) reduction and removal. The reactor was packed with polyurethane foam cubes and operated under different feeding and operating conditions of HRT, COD/〖SO〗_4^(2-) ratio and influent chromium(VI) concentration. A maximum chromium removal of 94.6% was achieved in the PBR when operated at an HRT of 24 h with COD/〖SO〗_4^(2-) ratio of .70 and influent...
Modeling and Characterizing Transient Behavior of Distillation Columns with Travelling Wave Theory
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor)
Abstract
Simulation and controlling nonlinear process is one of the challenging problems in academic and industrial research. Saving data for keeping history of process or arising number of calculation for optimization in control design, is forcing to decrease number of equation or order of system. One of the methods to decrease the order of distillation process is using the travelling wave theory. This solution shows god accuracy for simulation the behavior of distillation column. On the other hand finite difference method as a solver for distillation equation takes some time to converge to steady state condition and the numbers of calculation in this method are high. Finite difference method is...
Dehydration of THF Using Different Zeolites
, M.Sc. Thesis Sharif University of Technology ; Molaei Dehkordi, Asghar (Supervisor)
Abstract
The aim of this work was to investigate the performance of different kinds of Linde type A zeolite (LTA) for the dehydration of Tetrahydrofuran (THF)-water solution. Batch experiments were carried out to evaluate the effect of various operating parameters such as contact time, initial concentration, mixing temperature (10, 15,and 25 C), amount of adsorbent, and zeolite type(3A, 4A, and 5A zeolites). In theoretical studies, we took the advantage of several types of equilibrium model isotherms such as Langmuir, Freundlich, Dubin-Kaganer-Radushkevich (DKR) to describe the experimental adsorption data. Besides, three adsorption kinetic models including pseudo-first-order, pseudo-second-order,...
Adsorption Process Modeling by Rigorous Solution Method, on the Packed Bed Filled Zeolite
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Taghikhani, Vahid (Supervisor) ; Farhadi, Fatolla (Supervisor)
Abstract
The appearance of water in pipe lines of the natural gas transportation would cause several problems. In this regard, disparate methods have been developed to produce and refine of the natural gas, and one of the most common method is adsorption process. In this study, modeling and simulation of the adsorption process in the packed bed of zeolite 4A has been done. This research includes four steps, first, adsorption process and all types of adsorbent were investigated. Second, using rigorous solution method, equations of mass and energy balance derived. Third, using the collocation method and MATLAB programing, system equations of mass and energy was solved. Finally, accuracy of simulation...
Application of Sulfur Degrading Bacteria in Bioremediation
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamid Reza (Supervisor)
Abstract
The main objective of this research was to evaluate the application of a new strain of Brevundimonas naejangsanensis which is newly identified sulfate-reducing bacteria (SRB), in bioremediation. A laboratory scale packed bed reactor (PBR) was fabricated and operated to study the new bacteria’s feasibility on SO_4^(2-) reduction. The reactor was packed with polyurethane foam cubes and operated under different feeding and operating conditions of HRT, COD/SO_4^(2-) ratio and salinity. A maximum SO_4^(2-) reduction of 73.6% was achieved in the PBR when operated at an HRT of 12 h with SO_4^(2-) concentration of 670 mg/L, COD/SO_4^(2-) ratio of 1 and salinity of 3%. The results show that this...
Experimental Studies on Biodiesel Production Using Waste Frying Oil in a Hetergogeneous Catalytic Reaction
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamid Reza (Supervisor) ; Shaygan Salek, Jalaloddin (Supervisor) ; Pazouki, Mohammad (Co-Advisor)
Abstract
Biodiesel can be a good alternative for fossil diesel since it isrenewable, biodegradable and non-toxic. Also, in comparison with fossil fuels, it emits less air pollutants and greenhouse gases.Findacost effective and environmentally friendly wayforcontinuousproductionofbiodieselcanaddressmany of our environmental concerns. In this study, we applied heterogeneous alkali-catalyzed transesterification as method and used waste frying oil as a low cost feedstock for biodiesel production. The project was performed in two phases. First, experiments were conducted in astirred reactor to finda suitable catalyst which was strontium carbonate calcinated for 3:24 hours in 975̊C.
RPB(rotating...
RPB(rotating...
Carbon Dioxide Absorption with Chemical Reaction in the Presence of Magnetic Nanoparticles and Magnetic Field
, M.Sc. Thesis Sharif University of Technology ; Molaei Dehkordi, Asghar (Supervisor)
Abstract
It has been shown that absorption of carbon dioxide can be enhanced using nanoparticles and in the presence of magnetic field. In the present work, the influences of ferrofluids and magnetic fields on the absorption of CO2 in packed-bed contactors have been investigated carefully. In this regard, multi-tube approach has been applied to model the contactor. The simulation results were validated against experimental data reported in the literature in the absence of nanoparticles and magnetic fields and good agreement was obtained. The influences of variable operating conditions on the contactor performance were carefully investigated. It was found that for 3.4% volume percent of magnetic...
Modeling of multiple noncatalytic gas-solid reactions in a moving bed of porous pellets based on finite volume method
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 43, Issue 9 , 2007 , Pages 881-894 ; 09477411 (ISSN) ; Saboohi, Y ; Sharif University of Technology
2007
Abstract
A mathematical model is presented to simulate the multiple heterogeneous reactions with complex set of physicochemical and thermal phenomena in a moving bed of porous pellets. This model is based on both heat and mass transfer phenomena of gaseous species in a porous medium including chemical reactions at interfaces whose areas vary during the conversion. This model accounts for both the exothermic and endothermic reactions which can be equimolar or nonequimolar. Furthermore it considers simultaneously the reactions in the nonisothermal transient condition. A powerful technique based upon finite volume fully implicit approach has been implemented to solve the complicated governing equations...
A non-isothermal, transient model of a non-catalytic reaction in a packed bed with a multi-component high-temperature gas mixture
, Article 3rd M.I.T. Conference on Computational Fluid and Solid Mechanics, Boston, MA, 14 June 2005 through 17 June 2005 ; 2005 , Pages 1023-1025 ; 0080444814 (ISBN); 9780080444819 (ISBN) ; Saboohi, Y ; Sharif University of Technology
2005
Abstract
A mathematical model has been developed to simulate heterogeneous reactions with a complex set of physicochemical and thermal phenomena in a packed bed. These include the chemical reaction itself, the transport of gaseous species in the pores, the generation or consumption of heat by the reactions, and the transport of heat in the porous domain. Solution of complicated sets of governing equations is based upon the concept of a finite volume fully implicit approach. The model has then been applied to analyze the reduction of a hematite pellet in a moving packed bed reactor. © 2005 Elsevier Ltd
Mathematical model and energy analysis of ethane dehydration in two-layer packed-bed adsorption
, Article Particuology ; Volume 47 , 2019 , Pages 33-40 ; 16742001 (ISSN) ; Hosseini, S. H ; Ahmadi, G ; Olazar, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The 3A zeolites are excellent adsorbents for industrial-scale gas dehydration because of the low energy required for regeneration and ease of operation. A computational study of the dehydration of an industrial feed stream containing ethane and water was performed using an in-house code that included an appropriate equilibrium adsorption isotherm. The validated computational model was used to examine the impact of particle size on the process dynamics and the corresponding pressure drop. The water concentration along the adsorption column was also investigated. To increase the process capacity, the packed adsorption bed was divided into two distinct layers, which were operated with different...
Numerical investigations of fluid flow and lateral fluid dispersion in bounded granular beds in a cylindrical coordinates system
, Article Chemical Engineering and Technology ; Volume 30, Issue 10 , 2007 , Pages 1369-1375 ; 09307516 (ISSN) ; Turunen, I ; Yousefi, H ; Bastani, D ; Sharif University of Technology
2007
Abstract
Results are presented from a numerical study examining the flow of a viscous, incompressible fluid through a random packing of non-overlapping spheres at moderate Reynolds numbers, spanning a wide range of flow conditions for porous media. By using a laminar model including inertial terms and assuming rough walls, numerical solutions of the Navier-Stokes equations in three-dimensional porous packed beds resulted in dimensionless pressure drops in excellent agreement with those reported in a previous study. This observation suggests that no transition to turbulence could occur in the range of the Reynolds number studied. For flows in the Forchheimer regime, numerical results are presented of...
Kinetics, experimental and simulation studies of Chinese Hamster Ovary cell growth in a packed-bed bioreactor
, Article World Applied Sciences Journal ; Volume 15, Issue 11 , 2011 , Pages 1568-1575 ; 18184952 (ISSN) ; Tabandeh, F ; Zomorodipour, A. R ; Mohammad-Beigi, H ; Ebrahimi, S ; Habib Ghomi, H ; Sharif University of Technology
2011
Abstract
To figure out the relationship between nutrient deprivation and cell growth, simulation can be effective. In the present work, the growth of Chinese Hamster Ovary (CHO) cells was simulated based on stoichiometric and kinetics calculations. The simulation results were compared to the experimental data from a packed-bed bioreactor and a good agreement was observed. The kinetic parameters (K Glc, K Amn, K Lact and μ Max) were optimized by a genetic algorithm method using stoichiometric parameters (Y X/Glc, Y X/Amm, and Y Lac/Glc). The stoichiometric and kinetic parameters were used in the simulation to study the growth of CHO cells. The concentrations of the toxic by-products, ammonium and...
Modeling of sorption enhanced steam methane reforming in an adiabatic packed bed reactor using various CO2 sorbents
, Article Journal of Environmental Chemical Engineering ; Volume 9, Issue 5 , 2021 ; 22133437 (ISSN) ; Abbas, S. Z ; Maqbool, F ; Ramirez Solis, S ; Dupont, V ; Mahmud, T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
A 1-D heterogeneous model of sorption-enhanced steam methane reforming (SE-SMR) process in a packed bed reactor consisting of nickel catalyst well mixed with CO2 sorbent particles is investigated for three types of common sorbents. The performance of SE-SMR process is studied under low medium pressure conditions (3 – 11 bar) to find the optimum operating conditions. Optimal CaO sorption corresponding to 82% CH4 conversion and 85% H2 purity is found at 900 K, 3 bar, 3.5 kgm−2s−1 and S/C of 3.0. In contrast, lithium zirconate (LZC) and hydrotalcite (HTC) sorbents exhibited best sorptions under the operating conditions of 773 K, 5 bar and S/C of 3 with CH4 conversion of 91.3% and 55.2%, and H2...
Multi-objective optimization of industrial membrane SMR to produce syngas for Fischer-Tropsch production using NSGA-II and decision makings
, Article Journal of Natural Gas Science and Engineering ; Volume 32 , 2016 , Pages 222-238 ; 18755100 (ISSN) ; Farsi, M ; Eini, S ; Sharif University of Technology
Elsevier
2016
Abstract
Membrane reactors are an advanced technology with vast application capacities for equilibrium limited endothermic reactions. The main propose of this study is to offer an optimized packed-bed membrane steam methane reforming (SMR) tubular reactor for sustainable CH4 conversion by implementing triple-objective optimization model based on optimum H2/CO ratio for low temperature Fischer-Tropsch (F-T) process. In this study a one dimensional pseudo-homogeneous model based on mass, energy, and momentum conservation laws is used to simulate the behavior of a packed-bed membrane reactor for production of syngas by SMR. In the optimization section, the proposed work explores optimal values of...
Comparison of conventional and spherical reactor for the industrial auto-thermal reforming of methane to maximize synthesis gas and minimize CO2
, Article International Journal of Hydrogen Energy ; Volume 42, Issue 31 , 2017 , Pages 19798-19809 ; 03603199 (ISSN) ; Saeidi, S ; Najari, S ; Gallucci, F ; Sharif University of Technology
Abstract
Auto-thermal reforming (ATR), a combination of exothermic partial oxidation and endothermic steam reforming of methane, is an important process to produce syngas for petrochemical industries. In a commercial ATR unit, tubular fixed bed reactors are typically used. Pressure drop across the tube, high manufacturing costs, and low production capacity are some disadvantages of these reactors. The main propose of this study is to offer an optimized radial flow, spherical packed bed reactor as a promising alternative for overcoming the drawbacks of conventional tubular reactors. In the current research, a one dimensional pseudo-homogeneous model based on mass, energy, and momentum balances is...
Photocatalytic decomposition of direct red 16 and kinetics analysis in a conic body packed bed reactor with nanostructure titania coated Raschig rings
, Article Chemical Engineering Journal ; Volume 151, Issue 1-3 , 2009 , Pages 295-301 ; 13858947 (ISSN) ; Asgari, M ; Soleymani, A. R ; Taghavinia, N ; Sharif University of Technology
2009
Abstract
A conic body packed bed reactor, internally irradiated with a UV-C lamp and equipped with circulating upflow stream was employed to investigate the decomposition of a widely used azo dye, direct red 16, in water. The synthesized nanostructure TiO 2 photocatalyst particles were immobilized on the surface of transparent Raschig ring packings. Solutions with initial concentration of 30 mg L -1 of dye, within the range of typical concentration in textile waste waters, were treated under the mild operating conditions of natural pH of 6.75 and temperature of 25 °C. Investigations on the active species showed that hydroxyl radicals play the major role in the process, providing a perfect degradation...
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...
Chemically modified organic/inorganic nanoporous composite particles for the adsorption of reactive black 5 from aqueous solution
, Article Reactive and Functional Polymers ; Volume 86 , 2015 , Pages 7-15 ; 13815148 (ISSN) ; Shojaei, A ; Karimi, M ; Sharif University of Technology
Elsevier
2015
Abstract
In the present work, we report a chemically modified polyacrylamide/silica nanoporous composite adsorbent for the removal of reactive black 5 (RB5) azo dye from aqueous solutions. The composite adsorbent was synthesized in a packed bed and modified by ethylenediamine (EDA). The adsorbent was characterized by Fourier transformation infrared (FT-IR), thermogravimetric analysis (TGA), thermoporometry, Brunauer, Emmett and Teller (BET) method and scanning electron microscopy (SEM). Mechanical stability of the adsorbent was examined in a packed bed by following the back-pressure of the column. Pore diameter of the composite adsorbent in dry and wet states was estimated to be about 18.71 nm and...
Optimization of ferrous biooxidation rate in a packed bed bioreactor using Taguchi approach
, Article Chemical Engineering and Processing: Process Intensification ; Volume 46, Issue 10 , 2007 , Pages 935-940 ; 02552701 (ISSN) ; Yaghmaei, S ; Jafari, A ; Vossoughi, M ; Ghobadi, Z ; Sharif University of Technology
2007
Abstract
The biological oxidation of ferrous ion by iron-oxidizing bacteria is potentially a useful industrial process for removal of H2S from industrial gases, desulphurization of coal, removal of sulfur dioxide from flue gas, treatment of acid mine drainage and regeneration of an oxidant agent in hydrometallurgical leaching operations. The main purpose of this study was to find optimum values of the process parameters on the ferrous biooxidation rate by immobilization of a native Sulfobacillus species on the surface of low density polyethylene (LDPE) particles in a packed-bed bioreactor using Taguchi method. Five control factors, including temperature, initial pH of feed solution, dilution rate,...