Synthesis of Silicalite-1 Nanoparticles and Investigating the Effect of Seeding Steps on the Seeded Supports in Order to Prepare High Quality Zeolite Membrane
Sayed Fatemeh
Banihashemi
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
author
Ali
Ahmadpour
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
author
Majid
Pakizeh
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
author
Mahdi
Pourafsharichenar
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN
author
text
article
2012
per
In the present investigation, nanosized silicalite-1 powder was first synthesized as a seed with mean diameter of 40 nm by the hydrothermal method. Seeding of nanosized zeolite crystals on the support surface is one of key steps in the secondary growth synthesis method. Therefore, in order to increase the quality of the zeolite membrane, subsequent seeding steps were investigated by dip-coating technique. The seeded supports and silicalite-1 nanoparticles were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), N2-BET adsorption/desorption isotherm,Fourier Transform Infrared Spectroscopy (FT-IR), Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimeter (DSC). Examination of the number of seeding steps showed that three subsequent seeding steps would improve the quality of seed layer.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
1
11
https://www.nsmsi.ir/article_7123_29bc90c8bf73aa9fbfe6e5ee7fd1f9d6.pdf
A Study of the Mass Transport and Charge Propagation in the Cobalt Oxide Nanoflakes
Hossein
Heli
Department of Chemistry, Science and Research Branch, Islamic Azad University, Fars, I.R. IRAN
author
Hossein
Yadegari
Department of Chemistry, K.N. Toosi University of Technology, Tehran, I.R. IRAN
author
text
article
2012
per
A simple and efficient method was reported for the synthesis of conalt (II) oxide nanoflakes. Morphology and chemical structure of the nanoflakes were evaluated by different electron microscopy methods (scanning and transmission), X-ray diffraction, scanning tunneling microscopy and electrochemical methods. A comprehensive study on the electrochemical behavior of the nanoflakes at an interface with electrolyte, charge propagation and mass transport (counter ion diffusion) processes in the nanoflakes and the kinetic and mechanism of electrochemical reactions were performed by cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical reaction rate constants and counter cation diffusion coefficient into the nanoflakes at different potentials were reported.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
13
33
https://www.nsmsi.ir/article_7124_57d246286296af619fc9df9ada50ff71.pdf
Activity Coefficients of Major Ions and Salts in Urmia Salt Lake
Sima
Rezvantalab
Chemical Engineering Department, Urmia University of Technology, P.O. Box 57155/419 Urmia, I.R.
author
Elham
Jannatdoust
Chemical Engineering Department, Urmia University of Technology, P.O. Box 57155/419 Urmia, I.R. IRAN
author
Aref
Alipour
Mining Engineering Department, Urmia University of Technology, P.O. Box 57155/419 Urmia, I.R. IRAN
author
text
article
2012
per
All of researches have been done about Urmia Salt Lake up to now, are about its chemical composition. Whereas thermodynamics study of the lake and evaluation of single-ion and mean salt activity in order to prepare phase diagram has theoretical and practical importance. In this study, ionic and salt activity coefficients have computed in 25°C temperature, assuming homogenous chemical composition in the lake and using published information in recent years. By Pitzer model and its results, we have predicted solubility and saturation indexes for some minerals.Urmia Salt Lake brines were shown to be oversaturated with respect to magnezit and dolomite.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
35
43
https://www.nsmsi.ir/article_7160_5122243cfb742e9205496f34e46d816c.pdf
Electrolyte Solutions and Osmotic Coefficient of [BMIM][BF4] Ionic Liquid Using New GV-SAFT-MSA Equation of State
Vahab
Sahraei
Chemical Engineering Department, Sharif University of Technology, Tehran ,I.R. IRAN
author
Syrous
Ghotbi
Chemical Engineering Department, Sharif University of Technology, Tehran ,I.R. IRAN
author
Vahid
Taghikhani
Chemical Engineering Department, Sharif University of Technology, Tehran ,I.R. IRAN
author
Khodadad
Nazari
Research Institute of Petroleum Industry (RIPI), Tehran, I.R. IRAN
author
text
article
2012
per
In this work “Statistical Association Fluid Theory (SAFT)” Equation Of State (EOS) is applied for activity coefficient of electrolyte solution. For considering the presence of ions Mean Spherical Approximation (MSA) term is added to SAFT EOS. The SAFT EOS can predict the thermodynamic properties of associating fluids like H2O and by adding the MSA term, the thermodynamic properties of electrolyte solutions can be obtained. In this work a new term for hard-sphere reference fluid is used. The proposed model has three adjustable parameters. In this the work correlation of activity coefficient for 14 electrolyte solutions is considered. The results show that the proposed model can correlate very well the activity coefficient. The proposed model can also correlate better than Pitzer model the osmotic coefficient of ionic liquid solution [BMIM][BF4] as an organic salt at different temperatures.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
45
54
https://www.nsmsi.ir/article_7166_622afc6ad8737f1f6e223282c02415b2.pdf
Cation Exchange Resin Based on Polybutyl Methacrylate in Determination of Hemoglubin A1c
Maryam
Nickhoo
Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, I.R. IRAN
author
Habibollah
Baharvand
Iran Polymer & Petrochemical Institute, P.O. Box 14965-115 Tehran, I.R. IRAN
author
Homayon
AhmadPanahi
Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, I.R. IRAN
author
text
article
2012
per
Determination of glycated proteins is effective in the monitoring of long-term glucose control in individuals with diabetes mellitus. Nowadays micro-column ion-exchange chromatography that could separate the proteins is frequently used. In this system, the separation was carried out on an ion-exchange resin. One of these resins based on polybutyl methacrylate is synthesized, using suspension polymerization technique. The synthesized resin was characterized by analytical methods. FT-IR spectroscopy confirmed presence of carboxylic groups in the resin. Using Scanning Electron Microscope (SEM) and BET surface analysis techniques, respectively, macroporous structure of the resin was confirmed and specific surface area was determined. Application of the resin in separation of hemoglobin A1c was examined by UV-spectrophotometer as detector. It is shown that the synthesized macropore cation exchange resin with cation exchange capacity of 3.083 mEq / (g dry resin) is applicable for Hb A1c hemoglobin separations.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
55
62
https://www.nsmsi.ir/article_7167_28aee50e0ff3690a4c8483efcdbb20b8.pdf
Comparative Effect of Acid Treatment and DTPA Chelating Agent on Optical Properties of Chemi-Mechanical Pulp Bleached by Hydrogen Peroxide-Magnesium Hydroxide
Somayeh
Ghasemi
Department of Wood and Paper Science and Technology, Faculty of Natural Resources,
Tarbiat Modares University, Tehran, I.R. IRAN
author
Rabi
Behrooz
Department of Wood and Paper Science and Technology, Faculty of Natural Resources,
Tarbiat Modares University, Tehran, I.R. IRAN
author
text
article
2012
per
Appropriate composition of chemicals and optimizing of bleaching stages have important effect on bleached pulp quality. Transition metals have the greatest destructive effects on peroxide bleaching. One of the most effective of treatments for removing these metals is using of chelating agents. Since in some countries, the chelating material is classified as toxic substances. This research was done for evaluating effectiveness and the possibility of using acidic pre-treatment as an alternative for chelating materials in hydrogen peroxide bleaching of CMP based on Mg(OH)2. Evaluation of optical properties of the hand sheet papers for pretreatment by DTPA and acid washing showed that the DTPA pre-treated samples had the highest brightness and the lowest yellowness index and opacity. Also, transition metals measurements showed that the acid pre-treatment removed more magnesium ion and less Mn and Fe ions compared to DTPA. According to the research results, acid pre-treatment have less efficiency in metal elimination than DTPA.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
63
69
https://www.nsmsi.ir/article_7169_184020adfc0c468c8ec1d28ebc88ebbd.pdf
Sulfur Removal from Gasoline by Pervaporation
Masoumeh
Takbiri
Research Centre for Membrane Separation Processes, School of Chemical Engineering,
Iran University of Science and Technology (IUST), Tehran, I.R. IRAN
author
Tooraj
Mohammadi
Research Centre for Membrane Separation Processes, School of Chemical Engineering,
Iran University of Science and Technology (IUST), Tehran, I.R. IRAN
author
Afshin
Pak
Research Centre for Membrane Separation Processes, School of Chemical Engineering,
Iran University of Science and Technology (IUST), Tehran, I.R. IRAN
author
text
article
2012
per
Sulfur present in gasoline results in air pollution by SOx emissions. With the mixtures of thiophene/n-hexane making up the model gasoline, PDMS/PA composite membrane was used for sulfur removal from gasoline by pervaporation. Effects of sulfur content (0.3-0.6 wt.%), feed temperature (30-50 ºC), permeate pressure (23-100 mmHg) and feed flow rate (30-90 L/h) were investigated on pervaporation separation of n-hexane/thiophene binary mixtures. Douglas design was used to research the effects of operating parameters on total fluxes. Experimental results indicated that sulfur content and feed flow rate have negligible effects on total flux in comparison with feed temperature and permeate pressure. Increasing feed temperature, sulfur content, feed flow rate and decreasing permeate pressure, increase total flux. According to significance of feed temperature and permeate pressure, effects of these investigated on thiophene enrichment factors. Thiophene enrichment factor increased with decreasing feed temperature and permeate pressure. The highest enrichment factor of thiophene was obtained to be 1.5 at a feed temperature of 30 ºC and a permeate pressure of 23 mmHg.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
71
80
https://www.nsmsi.ir/article_7172_4dc2ce88eef63fcea5ed410c6e83e065.pdf
An Investigation on the Effects of Surface Activation and Acidic Pretreatment on Ilmenite Recovery
Mostafa
Maleki Moghadam
Department of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, I.R. IRAN
author
Abbas
Sam
Department of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, I.R. IRAN
author
Hasan
Haji Amin Shirazi
Department of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, I.R. IRAN
author
text
article
2012
per
Application of flotation in ilmenite fine particles recovery was not proved promising in previous studies, due to very limited active sites on ilmenite which is responsible for poor flotability of the mineral. In this work, surface activation and acidic pretreatment were examined to improve ilmenite floatability. Experiments were conducted on samples collected from the feed to line 3, containing 6.36% TiO2. The samples were ground to minus 106µm. Taguchi method was used to design experiments leading to optimal operational conditions, which found to be 700 g/t Clarient Flotinor SM 15 and Flotinor FS mixture with ratio 1/1 as collectors, 15 minutes as conditioning time and pH at 8.5. It is shown that using Pb(NO3)2 as surface activation with dosages up to 150 g/t, resulted in about 50% increase in recovery with a corresponding 9% increase in separation efficiency. Additionally, the concentrate grade was increased about 14% by using acidic pretreatment before conditioning.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
81
88
https://www.nsmsi.ir/article_7174_678ddbab29eb1232c10bf2ed2cd43684.pdf
Investigation on Mixing Time in a Dual Rushton Impeller Stirred Tank
Firuz
Fakheri
Transport Phenomena Research Center, Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996 Tabriz, I.R. IRAN
author
Jafarsadegh
Moghaddas
Transport Phenomena Research Center, Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996 Tabriz, I.R. IRAN
author
text
article
2012
per
Mixing time can be used as a comparative measurement of mixers efficiency. The present study is an investigation of the effect of important operating variables (impeller rotational speed and air bubbles present) on the mixing time in an agitated tand by dual Rushton turbine. This study has shown that the mixing time decreases with an increase in impeller speed and the effect of gas flow rate on the mixing time depends on the impeller rotational speeds. The mixing time obtained by conductivity method has been compared with the PLIF technique by Moghaddas. According to the experimental results, the mixing times which were obtained from the conductivity technique have a good agreement with the PLIF technique. Therefore, the conductivity technique is a simple, accurate and cost effective technique to replace expensive way. Also, the mixing time obtained by using the correlation and formula at large scale of mixing systems was incorrect, and the number of available correlation in this scale of mixing systems is limited. In the present study,to predict of mixing time in a dual Rushton impeller stirred, a six-concentration obtained experimentally and that calculated from compartment model was obtained.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
89
100
https://www.nsmsi.ir/article_7176_40cb992e23bbe9d0230c2debb5772adf.pdf
Study of Mixing of Phases inside the Sieve Tray Using Computational Fluid Dynamics
Mahmood Reza
Rahimi
Chemical Engineering Department, Faculty of Engineering, Yasouj University,Yasouj, I.R. IRAN
author
text
article
2012
per
In the present study a three-dimensional Eulerian-Eulerian Computational Fluid Dynamics (CFD) model was developed to predict the hydrodynamics behavior of industrial scale sieve trays, for study of phase mixing inside the tray. The dispersed gas and the continuous liquid phases are as two interpenetrating phases. Three parameters consisting distribution of density of mixture, volume fraction distribution and interfacial area density were evaluated as characteristics of mixing. Four regions consisting near wall region, the area between adjacent holes, behind the entrance and exit weirs are distinguished as regions with poor mixing. Plug flow with almost uniform phase mixing was seen at central region of tray. The extent of mixing is depended on the gas and liquid flow rates, and the response of central region and above mentioned 4 poor mixing areas to change of gas and liquid flow rates are different. The results showed that proposed model can well predict some details of phase mixing characteristics, while known methods have not ability to show them.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
101
113
https://www.nsmsi.ir/article_7178_c39df0f0acbf881331e1e6633ef4ce57.pdf
Determination of Scale Formation in Iranian Oil Reservoir During Water Injection Process
Samaneh
Saboor
School of Chemical, Petroleum and Gas Engineering, Semnan University,
P.O. Box 35195-363, Semnan, I.R. IRAN
author
Mohammad Nader
Loftollahi
School of Chemical, Petroleum and Gas Engineering, Semnan University,
P.O. Box 35195-363, Semnan, I.R. IRAN
author
Pouya
Mottahedin
School of Chemical, Petroleum and Gas Engineering, Semnan University,
P.O. Box 35195-363, Semnan, I.R. IRAN
author
text
article
2012
per
The Pitzer model was used to predict the quantity and kind of scales for some cases of sea and formation water. These scales are formed because of injection incompatible water with the formation water or change in temperature and pressure. These scales are barium sulfate, strontium sulfate, calcium sulfate)gypsum and anhydrate( that create many problems in oil reservoir or in producing well. Obtained results showed that maximum amount of scales are formed for higher ratio of formation water to sea water and often amount of strontium sulfate is greater than other scales. Also due to more solubility of gypsum, amount of anhydrate is ignorable. With increasing temperature, amount of strontium sulfate and calcium sulfate increases and barium sulfate decreases and increasing pressure, decreases supersaturation and amount of sulfate scales. For temperature and pressure condition in this research, effect of pressure is less than other parameters. The various calculation results demonstrated that the proposed model is in good agreement with the reported field observation.
Nashrieh Shimi va Mohandesi Shimi Iran
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1022-7768
31
v.
1
no.
2012
115
123
https://www.nsmsi.ir/article_7180_70777563b6cfbcf0a238d25d2a5d3d00.pdf