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    Comparative Study of Two PWC Methodologies on HDA Process

    , M.Sc. Thesis Sharif University of Technology Poorazimi, Sina (Author) ; Pishvaie, Mahmood Reza (Supervisor)
    Abstract
    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)
    Abstract
    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... 

    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)
    Abstract
    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... 

    Synthesis Deuterated Aromatic Compunds by Supercritical Method

    , M.Sc. Thesis Sharif University of Technology Shadjirati, Yasamin (Author) ; Outokesh, Mohammad (Supervisor) ; Sajadi, Soudeh (Supervisor)
    Abstract
    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... 

    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)
    Abstract
    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... 

    Characterization of Micromixing and Determination of Mass-Transfer Coefficient in a new Double-Spinning-Disk Contactor

    , M.Sc. Thesis Sharif University of Technology Mirzaei, Mohammad Ali (Author) ; Molaei Dehkordi, Asghar (Supervisor)
    Abstract
    High mixing efficiency and high liquid-liquid mass transfer rate are two key features of spinning disk contactors. This work presents the experimental investigation of mixing and liquid-liquid mass transfer characteristics in a new double coaxial spinning disks contactor. The micromixing efficiency was investigated using a standard system of competitive parallel reaction known as iodide/iodate test reaction. The influences of various operating conditions such as the rotational speed of the disks, the direction of rotation, the feed radial location, the feed distribution pattern, the distance between the disks, and the feed flow rate on the mixing quality were examined carefully. The obtained... 

    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)
    Abstract
    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... 

    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)
    Abstract
    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... 

    Treatment of oilfield produced water by dissolved air precipitation/solvent sublation

    , Article Journal of Petroleum Science and Engineering ; Volume 80, Issue 1 , 2011 , Pages 26-31 ; 09204105 (ISSN) Bayati, F ; Shayegan, J ; Noorjahan, A ; Sharif University of Technology
    Abstract
    Dissolved air precipitation/solvent sublation (DAP/SS) was used for treatment of simulated and real oilfield produced water to generate very fine bubbles which are necessary for effective separation. In this method micro bubbles produced by saturation of air in a pressurized packed column were released in an atmospheric column leading the bubbles to raise resulting trapped contaminants in the Gibbs layer around them to be removed by a layer of immiscible solvent at the top of column. The method was conducted to solutions including Benzene, Toluene and Chlorobenzene (ClB) as part of BTEX contaminants in produced water, mixture of them as simulated produced water and real oilfield produced... 

    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
    2005
    Abstract
    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  

    Thermodynamic analysis of application of organic Rankine cycle for heat recovery from an integrated DIR-MCFC with pre-reformer

    , Article Energy Conversion and Management ; Volume 67 , 2013 , Pages 197-207 ; 01968904 (ISSN) Vatani, A ; Khazaeli, A ; Roshandel, R ; Panjeshahi, M. H ; Sharif University of Technology
    2013
    Abstract
    This work deals with waste heat recovery from a proposed direct internal reforming molten carbonate fuel cell (DIR-MCFC), including an integrated pre-reformer. In this regard, some advantages are attainable over exhaust gas recycling. For instance, due to low temperature in the pre-reformer, carbon deposition and coke formation resulting from higher hydrocarbons can be eliminated. In this study, the cathode outlet provides the heat requirement for the pre-reforming process. After partial heat recovery from the cathode outlet, the stream still has a considerable energy and exergy (352.55 °C and 83.687 kW respectively). This study investigates waste heat recovery from the proposed DIR-MCFC,... 

    Synthesis of SiOC/Al2O3 nano/macro composites through PDC method; investigation of potentials as layers of a packed bed reactor membrane

    , Article Ceramics International ; Volume 46, Issue 11 , 2020 , Pages 19000-19007 Abdollahi, S ; Paryab, A ; Rahmani, S ; Akbari, M ; Sarpoolaky, H ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Thanks to a wide range of pore sizes by nano/macro composites of SiOC/Al2O3, such composites can serve as different layers of the structure of Packed Bed Reactor Membranes (PBRM). In the present study, the Polymer-Derived Ceramics method (PDC) has been used to synthesize nano/macro structures. Firstly, the effect of toluene as an extra carbon source on structure and microstructure of SiOC glass-ceramics was evaluated, such that, 4% (Vol) toluene was recognized as the proper amount to facilitate the synthesis of β-SiC at 1300 °C proved by XRD, Raman spectroscopy, and HR-TEM. Moreover, the presence of micro/meso-porosities was assessed by BET and TEM, indicating the capability of SiOC to serve... 

    Synthesis and application of silica aerogel-MWCNT nanocomposites for adsorption of organic pollutants

    , Article Scientia Iranica ; Volume 17, Issue 2 F , 2010 , Pages 122-132 ; 10263098 (ISSN) Bargozin, H ; Amirkhani, L ; Moghaddas, J. S ; Ahadian, M. M ; Sharif University of Technology
    Abstract
    Silica aerogel-multi wall carbon nanotube composites were synthesized successfully with a waterglass precursor and an ambient pressure drying method. Pure silica aerogels are so fragile that they cannot be used easily. Carbon nanotubes (MWCNT) were used as reinforcements to strengthen the mechanical properties of pure silica aerogels. Results show that inserting small amounts of MWCNT causes silica aerogels to monolith. By addition of MWCNT, monolith nanocomposites were produced with 800 m2/g surface area and a 140° contact angle. Results show that the silica aerogels and reinforced composites have an excellent adsorption property for the removal of organic pollutants from water. The average... 

    Synthesis and application of diethanolamine-functionalized polystyrene as a new sorbent for the removal of p-toluenesulfonic acid from aqueous solution

    , Article Journal of Industrial and Engineering Chemistry ; Volume 30 , October , 2015 , Pages 281-288 ; 1226086X (ISSN) Davarpanah, M ; Ahmadpour, A ; Rohani Bastami, T ; Dabir, H ; Sharif University of Technology
    Korean Society of Industrial Engineering Chemistry  2015
    Abstract
    Polystyrene resin was functionalized by diethanolamine for the efficient removal of p-toluenesulfonic acid (p-TSA) from aqueous solution. Functionalized adsorbent (DEA-PS) was characterized by elemental analysis, Fourier transform infrared spectroscopy, point of zero charge measurement and field-emission scanning electron microscopy. According to the results, maximum removal of p-TSA was observed at the pH range of 2.5-5. The adsorption kinetics of p-TSA onto DEA-PS was represented by pseudo-first-order model and the equilibrium data followed Langmuir model well. The adsorption process was endothermic and spontaneous, along with the positive change of entropy. The regeneration of DEA-PS was... 

    Supported copper and cobalt oxides on activated carbon for simultaneous oxidation of toluene and cyclohexane in air

    , Article RSC Advances ; Volume 5, Issue 7 , Dec , 2015 , Pages 5107-5122 ; 20462069 (ISSN) Zabihi, M ; Khorasheh, F ; Shayegan, J ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    Copper and cobalt oxides supported on almond shell derived activated carbon (AC) with different loadings were synthesized by sequential and co-deposition-precipitation methods leading to Cu(shell)/Co(core)/AC, Co(shell)/Cu(core)/AC and Cu-Co(mixed)/AC catalysts that were subsequently used for catalytic oxidation of gaseous mixtures of toluene and cyclohexane in air in a tubular flow reactor. The catalysts and the support were characterized by Boehm test, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy... 

    Supercritical synthesis and in situ deposition of PbS nanocrystals with oleic acid passivation for quantum dot solar cells

    , Article Materials Chemistry and Physics ; Volume 156 , 2015 , Pages 163-169 ; 02540584 (ISSN) Tavakoli, M. M ; Simchi, A ; Aashuri, H ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Colloidal quantum dot solar cells have recently attracted significant attention due to their low-processing cost and surging photovoltaic performance. In this paper, a novel, reproducible, and simple solution-based process based on supercritical fluid toluene is presented for in situ growth and deposition PbS nanocrystals with oleic-acid passivation. A lead precursor containing sulfur was mixed with oleic acid in toluene and processed in a supercritical fluid condition at different temperatures of 140, 270 and 330 °C for 20 min. The quantum dots were deposited on a fluorine-doped tin oxide glass substrate inside the supercritical reactor. Transmission electron microscopy, X-ray diffraction,... 

    Spatiotemporal description of BTEX volatile organic compounds in a middle eastern megacity: tehran study of exposure prediction for environmental health research (Tehran SEPEHR)

    , Article Environmental Pollution ; Volume 226 , 2017 , Pages 219-229 ; 02697491 (ISSN) Amini, H ; Hosseini, V ; Schindler, C ; Hassankhany, H ; Yunesian, M ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    Abstract
    The spatiotemporal variability of ambient volatile organic compounds (VOCs) in Tehran, Iran, is not well understood. Here we present the design, methods, and results of the Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR) on ambient concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX. To date, this is the largest study of its kind in a low- and middle-income country and one of the largest globally. We measured BTEX concentrations at five reference sites and 174 distributed sites identified by a cluster analytic method. Samples were taken over 25 consecutive 2-weeks at five reference sites (to be used for... 

    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
    Abstract
    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  

    Silver nanoparticles-polyaniline nanocomposite for microextraction in packed syringe

    , Article Chromatographia ; Vol. 77, issue. 5-6 , 2014 , pp. 397-403 ; ISSN: 00095893 Bagheri, H ; Banihashemi, S ; Sharif University of Technology
    Abstract
    A rapid, convenient and reliable method for microextraction in packed syringe (MEPS) of the loop diuretic furosemide (FUR) in urine along with high-performance liquid chromatography (HPLC) was developed. A nanocomposite based on silver nanoparticles/polyaniline (Ag-NPs/PANI) was synthesized and used as the MEPS packing material. This nanocomposite was prepared conveniently using interfacial polymerization without the need for any templates or functional dopants. The feasibility of the synthesized nanocomposites was examined by isolation of FUR from diluted urine samples. After extraction, the analyte was desorbed by 200 μL of methanol. It was then dried and the residue was dissolved in 30 μL... 

    Roles of inorganic oxide nanoparticles on extraction efficiency of electrospun polyethylene terephthalate nanocomposite as an unbreakable fiber coating

    , Article Journal of Chromatography A ; Volume 1375 , 2015 , Pages 8-16 ; 00219673 (ISSN) Bagheri, H ; Roostaie, A ; Sharif University of Technology
    Elsevier  2015
    Abstract
    In the present work, the roles of inorganic oxide nanoparticles on the extraction efficiency of polyethylene terephthalate-based nanocomposites were extensively studied. Four fiber coatings based on polyethylene terephthalate nanocomposites containing different types of nanoparticles along with a pristine polyethylene terephthalate polymer were conveniently electrospun on stainless steel wires. The applicability of new fiber coatings were examined by headspace-solid phase microextraction of some environmentally important volatile organic compound such as benzene, toluene, ethylbenzene and xylene (BTEX), as model compounds, from aqueous samples. Subsequently, the extracted analytes were...