Search for: toluene
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    Natural gas hydrate promotion capabilities of toluene sulfonic acid isomers

    , Article Polish Journal of Chemical Technology ; Vol. 16, Issue. 1 , 2014 , pp. 97-102 ; ISSN: 1899-4741 Jarrahian, A ; Heidaryan, E ; Sharif University of Technology
    The purpose of this study was to investigate the natural gas hydrate promotion capabilities of the hydrotrope Toluene Sulfonic Acid (TSA) isomers as an additive. The capabilities of TSA isomers were measured with different concentrations. The optimum additive concentration for hydrate formation was determined for the given pressure, temperature, mixing condition, and cooling time. The natural gas hydrate promotability of para-TSA was found to be 20% and 35% more than meta-TSA and ortho-TSA respectively at the optimum concentration. Beyond the optimum TSA concentration, the hydrate formation declined as the ice formation reduced the overall gas-to-water volume ratio in the hydrates  

    Synthesis and Optimization of Metal Oxide Catalysts Supported on Nano-structured Alumina for Oxidation of Toluene from Contaminated Air

    , M.Sc. Thesis Sharif University of Technology Jafari, Mina (Author) ; Khorashe, Farhad (Supervisor) ; Kazemeni, Mohammad (Supervisor)
    Exhaust gases from poultry rendering facilities contain volatile organic compounds (VOCs) that are a nuisance, odorous, and smog and particulate matter precursors. Other available treatment options, such as thermal and catalytic incineration require temperature intensive inputs and form additional greenhouse gases. Hence, an inexpensive alternative technology is needed to eliminate these air pollutants. This research investigated the catalytic oxidation of toluene vapors using novel dispersed nano catalysts derived from new preparation method. The combined impregnation (IMP) and deposition-precipitation (DP) was used to prepare supported transition metal oxide catalyst over commercial and... 

    Biodegradation of aromatic hydrocarbons in a compost biofilter

    , Article Journal of Chemical Technology and Biotechnology ; Volume 78, Issue 7 , 2003 , Pages 795-801 ; 02682575 (ISSN) Torkian, A ; Dehghanzadeh, R ; Hakimjavadi, M ; Sharif University of Technology
    Two laboratory-scale biofilters filled with the same type of packing material were operated at different gas flow rates and influent concentrations of toluene and xylene in order to investigate their performance in treating waste gas streams. The columns contained a mixture of municipal compost as a base material and wood chips as a bulking agent in an 80:20 ratio; the porosity was 54%. Microbial acclimation was achieved by addition of nutrient-enriched solution along with pollutants for a week by daily mixing and natural aeration. During the start-up of the systems with inlet concentrations of 20 and 70 ppm for toluene and xylene, respectively, high biomass growth resulted in pressure drops... 

    Degradation of benzene, toluene, and xylene (BTX) from aqueous solution by isolated bacteria from contaminated sites

    , Article Research on Chemical Intermediates ; Volume 41, Issue 1 , January , 2015 , Pages 265-275 ; 09226168 (ISSN) Mesgari Shadi, A ; Yaghmaei, S ; Vafaei, F ; Khataee, A. R ; Hejazi, M. S ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    The present study was carried out to evaluate the degradation efficiency of benzene, toluene, and xylene (BTX) by isolated bacteria from various petroleum-hydrocarbons contaminated sites. Five isolated bacteria were selected for testing BTX biodegradation from liquid culture media. Each of these bacteria was able to degrade BTX but with different efficiencies. Maximum biodegradation efficiency for benzene (more than 70 %) was obtained by Gram-positive coccobacillus, Gram-positive coccus and Gram-negative bacillus bacteria, for toluene (60 %) and xylene (70 %) by Gram-positive coccobacillus and Gram-negative coccobacillus. It was found that the presence of xylene in the substrate mixture... 

    Experimental and simulation investigation on separation of binary hydrocarbon mixture by thermogravitational column

    , Article Journal of Molecular Liquids ; Volume 268 , 2018 , Pages 791-806 ; 01677322 (ISSN) Hashemipour, N ; Karimi Sabet, J ; Motahari, K ; Mahruz Monfared, S ; Amini, Y ; Moosavian, M. A ; Sharif University of Technology
    Elsevier B.V  2018
    In this article, experimental and numerical investigations are performed to study a thermogravitational column (TGC) for the separation of toluene/n-heptane mixture. This research has tried to determine the main significant parameters and their effects on the performance of the process. In experimental examinations, the influence of the main parameters such as feed flow rate, cut and temperature gradient on the performance of the TGC efficiency is studied. In addition, computational fluid dynamics is used to simulate the separation process in this review. The response surface methodology (RSM) was also applied to minimize the number of runs and investigate the optimum operating conditions.... 

    Synthesis Deuterated Aromatic Compunds by Supercritical Method

    , M.Sc. Thesis Sharif University of Technology Shadjirati, Yasamin (Author) ; Outokesh, Mohammad (Supervisor) ; Sajadi, Soudeh (Supervisor)
    Green chemistry seeks to reduce or eliminate the use of hazardous substances in the chemical industry through the development of new products and processes .The replacement of harmful, widely used solvents and reagents is a key part of this approach. Supercritical fluid such as CO2 or water are good solvent for replaceement Exchange reactions involving the displacement of hydrogen bonded to carbon by deuterium are of interest in a broad variety of disciplines, such as the preparative chemistry of isotopically labeled materials, fundamental studies of carbonehydrogen bond activation processes, and studies of the nature of catalysts. The low cost of water and its environmental friendliness... 

    Efficient recyclable catalytic system for deoxygenation of sulfoxides: Catalysis of ionic liquid-molybdenum complexes in ionic liquid solution

    , Article New Journal of Chemistry ; Volume 36, Issue 4 , Dec , 2012 , Pages 971-976 ; 11440546 (ISSN) Bagherzadeh, M ; Ghazali Esfahani, S ; Sharif University of Technology
    Three newly synthesized room temperature ionic liquids containing molybdate anion, [DMIm][MoO 2(NCS) 4], [RPy][MoO 2(NCS) 4] (R = butyl or decyl), and previously reported [BMIm][MoO 2(NCS) 4] were used as catalysts for the reduction of sulfoxides. For facilitating the recyclability of the catalysts, the ionic liquids [RMIm][PF 6] and [RPy][PF 6] (RMIm = 1-n-alkyl-3-methylimidazolium, RPy = 1-n-alkylpyridinium) were applied as ionic solvents and toluene is used as solvent for the organic phase. Molybdenum salts immobilized in RTILs constituted a reusable and efficient heterogeneous catalyst system. A maximum conversion (>99%) was achieved for reduction of diphenyl sulfoxide to diphenyl... 

    Design and Construction the Low Cost Catalyst for Removal of VOCs from Air

    , M.Sc. Thesis Sharif University of Technology Fahimirad, Mahdi (Author) ; Shaygan Salek, Jalaloddin (Supervisor)
    Nowadays, increased pollutants in the air threat the society health condition and Volatile Organic Compounds (VOCs) are the most hazardous ones among them. In the present study, catalytic oxidation as a prominent of the VOCs removal method from air, have attracted attentions due to high removal efficiency and suitable kinetic reaction. Because of its common industrial applications, toluene is intended to be eliminated through a low cost carbon supported catalyst which is synthesised in the laboratory. Construction method, carbonaceous support type, catalyst metal and its load, calcination temperature and time are among influencing design characteristics. A combination of Impregnation and... 

    One-pot reductive amination of aldehydes by the dihydropyridine in water

    , Article Scientia Iranica ; Volume 19, Issue 6 , December , 2012 , Pages 1591-1593 ; 10263098 (ISSN) Ghafuri, H ; Hashemi, M. M ; Sharif University of Technology
    An efficient, highly chemoselective and simple synthesis of secondary amines via reductive amination of aldehydes, aromatic amines and inexpensive and easily accessible Diethyl 2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate (DHP) in the presence of catalytic amounts of p-toluenesulfonic acid (PTSA) in water in good to excellent yields is reported  

    Platinum extraction from spent catalysts by TOPO utilizing RSM technique

    , Article Advanced Materials Research ; Volume 548 , 2012 , Pages 186-192 ; 10226680 (ISSN) ; 9783037854532 (ISBN) Nejad, H. H ; Kazemeini, M ; Fattahi, M ; Sharif University of Technology
    In this research, data on liquid-liquid extraction of platinum from commercial spent catalysts by trioctylphosphine oxide (TOPO) in toluene were experimentally obtained. Alkaline metal salts were used to optimize the separation process. Best Salting-out effect was obtained by KCl which extracted up to 90% of platinum utilizing TOPO. Furthermore, extraction percentages of Pt and Al depending upon different factors were investigated. It was observed that the extraction process was kinetically fast and achieving the equilibrium time took less than 30 seconds. Optimized points obtained utilizing response surface methodology (RSM) by the "Design Expert" software in order to minimize the... 

    (Liquid + liquid) equilibrium for ternary mixtures of {heptane + aromatic compounds + [EMpy][ESO4]} at T = 298.15 K

    , Article Journal of Chemical Thermodynamics ; Volume 43, Issue 10 , 2011 , Pages 1530-1534 ; 00219614 (ISSN) Mirkhani, S. A ; Vossoughi, M ; Pazuki, G. R ; Safekordi, A. A ; Heydari, A ; Akbari, J ; Yavari, M ; Sharif University of Technology
    (Liquid + liquid) equilibrium (LLE) data for the ternary systems (heptane + toluene + 1-ethyl-3-methylpyridinium ethylsulfate) and (heptane + benzene + 1-ethyl-3-methylpyridinium ethylsulfate) were measured at T = 298.15 K and atmospheric pressure. The selectivity and aromatic distribution coefficients, calculated from the equilibrium data, were used to determine if this ionic liquid can be used as a potential extracting solvent for the separation of aromatic compounds from heptane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations  

    Pervaporation of toluene and iso-octane through poly(vinyl alcohol)/graphene oxide nanoplate mixed matrix membranes: Comparison of crosslinked and noncrosslinked membranes

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 7 , 2018 ; 00218995 (ISSN) Khazaei, A ; Mohebbi, V ; Behbahani, R. M ; Ramazani S. A., A ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Removal of aromatic compounds from fuel is an essential requirement in new environmental policies. In the present study, poly(vinyl alcohol)/graphene oxide (GO) mixed matrix membranes were prepared and applied to the separation of toluene from iso-octane by pervaporation, considering the similarity and interaction between graphene and aromatics. The effects of crosslinking and GO content on separation efficiency have been investigated in detail. Owing to the high affinity of GO with toluene through s and π bonds, the selectivity of the membranes was increased by incorporating a low amount of GO. The results also indicated that noncrosslinked membranes have higher selectivity and permeation... 

    The selective aerobic oxidation of methylaromatics to benzaldehydes using a unique combination of two heterogeneous catalysts

    , Article Organic and Biomolecular Chemistry ; Volume 3, Issue 5 , 2005 , Pages 725-726 ; 14770520 (ISSN) Rajabi, F ; Clark, J. H ; Karimi, B ; Macquarrie, D. J ; Sharif University of Technology
    A unique combination of a supported cobalt complex and the first example of supported NHPI in acetic acid gives a surprisingly stable heterogeneous catalytic system for the selective aerobic oxidation of methylaromatics to benzaldehydes at atmospheric pressure. © The Royal Society of Chemistry 2005  

    Analysis and interaction of exergy, environmental and economic in multi-objective optimization of BTX process based on evolutionary algorithm

    , Article Energy ; Volume 59 , 2013 , Pages 147-156 ; 03605442 (ISSN) Sahraei, M. H ; Farhadi, F ; Boozarjomehry, R. B ; Sharif University of Technology
    In this paper sustainability analysis (exergy, environmental and economic) and multi-objective optimization for an aromatic plant are provided and interactions between decision variables are discussed. Environmental evaluation shows that the cancer human toxicity and global warming are the most important environmental concerns and the weight of EIs (environmental impacts) are mainly due to process wastes. The optimizations results demonstrate parameters like reactor temperature have a wide range in the optimizations while some variables, such as extraction unit variables have the same value. Utility EI reduction occurred in economic and exergy optimizations rather than environmental... 

    Degradation of BTEX in groundwater by nano-CaO2 particles activated with L-cysteine chelated Fe(III): enhancing or inhibiting hydroxyl radical generation

    , Article Water Supply ; Volume 21, Issue 8 , 2021 , Pages 4429-4441 ; 16069749 (ISSN) Sun, X ; Ali, M ; Cui, C ; Lyu, S ; Sharif University of Technology
    IWA Publishing  2021
    The simultaneous oxidation performance of benzene, toluene, ethylbenzene, and xylene (BTEX) by nanoscale calcium peroxide particles (nCaO2) activated with ferric ions (Fe(III)) and the mechanism of the enhancement of BTEX degradation by L-cysteine (L-cys) were investigated. The batch experimental results showed that the nCaO2/Fe(III)/L-cys process was effective in the destruction of BTEX in both ultrapure water and actual groundwater. A proper amount of L-cys could enhance BTEX degradation due to the promotion of Fe(II)/Fe(III) redox cycles by the participation of L-cys, but an excessive presence of L-cys would cause inhibition. Adding 1.0 mM L-cys to the nCaO2/Fe(III) system, the... 

    Effect of Relative Humidity on Catalytic Combustion of Toluene over Nano Copper Based Catalysts with Nano Alumina Supports

    , M.Sc. Thesis Sharif University of Technology Esmailirad, Mohammad Reza (Author) ; Khorasheh, Farhad (Supervisor) ; Badkhshann, Amir (Supervisor)
    Volatile organic materials are amongst the most important air pollutants that presence of the moisture in polluted air during oxidation process are the most difficult to remove volatile contaminants using catalysts. In this study, nano-copper oxide catalyst on nano-alumina for complete oxidation of toluene in the presence of moisture at different temperatures and atmospheric pressure were examined. Alumina basic using co-precipitation and sol-gel methods have been synthesized, which is for the first time that alumina tri-second-butyl pre-manufacturer have been used for gamma-nano-alumina by sole gel method was used. Surface properties of synthesized nano-alumina have been studies by various... 

    Comparative Study of Two PWC Methodologies on HDA Process

    , M.Sc. Thesis Sharif University of Technology Poorazimi, Sina (Author) ; Pishvaie, Mahmood Reza (Supervisor)
    Plantwide control plays a significant role in both industrial and academic fields. In this work, two plantwide control methodologies, “Self-Optimiaing Control (SOC)” and “Integrated Framework of Simulation and Heuristic (IFSH)”, have been applied on toluene hydrodealkilation process. Consequently, the performance of each methodology has been evaluated and compared due to the same process disturbance scenarios.The results are as follows: Although self-optimiaing control includes lots of optimization efforts, dynamic performance of the plant dose not exhibit notable differences. Therefore, Integrated framework of simulation and heuristic methodology is preferable for hydrodealkilation... 

    Design and Synthesis of Supported Metal Oxide Catalysts on Activated Carbon for Removal of VOCs from Air

    , Ph.D. Dissertation Sharif University of Technology Zabihi, Mohammad (Author) ; Shaygan Salek, Jalaloddin (Supervisor) ; Khorasheh, Farhad (Supervisor)
    Emission of aromatic and aliphatic compounds to atmosphere is a major environmental concern for many urban societies. Catalytic oxidation of volatile organic compounds (VOCs) is an efficient and low operating cost technology for reduction of air pollution.
    First, dispersed copper oxide nano-catalysts supported on almond shell-based activated carbon were prepared for catalytic oxidation of toluene in air. The Response Surface Methodology (RSM) was used to express the catalyst removal efficiency in terms of catalyst metal loading and calcination temperature. Calcination temperature had a significant effect on the catalyst activity only at high metal loadings (upper 8% wt.). Two different... 

    Numerical and Experimental Analysis of Homogeneous Charge Compression Ignition with Normal Paraffins, Branched-chain Paraffins and Aromatics Combined Fuels

    , Ph.D. Dissertation Sharif University of Technology Reyhanian, Masoud (Author) ; Hosseini, Vahid (Supervisor) ; Mozafari, Ali Asghar (Supervisor)
    The purpose of this dissertation is to experimentally and numerically investigate the effect of molecular structure, composition, and physical and chemical properties of fuel on HCCI combustion. A well-equipped laboratory was set up to perform the required tests, capable of performing HCCI tests with different fuels. All tests used a single-cylinder diesel engine modified to operate in HCCI mode. Also, for numerical simulation, a chemical kinetic multi-zone model was developed to predict HCCI combustion behavior with appropriate accuracy. To investigate the effect of fuel chemical structure on HCCI combustion, three fuels, toluene, iso-octane and normal heptane, with entirely different... 

    Simple and green oxidation of cyclohexene to adipic acid with an efficient and durable silica-functionalized ammonium tungstate catalyst

    , Article Catalysis Communications ; Vol. 43 , 5 January , 2014 , pp. 169-172 Vafaeezadeh, M ; Mahmoodi Hashemi, M ; Sharif University of Technology
    A novel silica-functionalized ammonium tungstate interphase catalyst has been reported as a non-nitric acid route for adipic acid production from one-pot oxidative cleavage of 30% hydrogen peroxide and catalytic amounts of p-toluenesulfonic acid (PTSA). The catalyst has been simply prepared by commercially available starting material. The structure of the catalyst has been investigated using FT-IR spectroscopy, atomic absorption, TEM, SEM and XRD analysis. The catalyst has shown good to high activity even up to 10 runs of reaction. Simple preparation of the catalyst, avoids using harmful phase transfer catalyst (PTC) and/or chlorinated additives are among the other benefits of this work