Search for: desulfurization
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    A review on the methods in diesel desulfurization

    , Article Current Analytical Chemistry ; Volume 17, Issue 6 , 2021 , Pages 815-830 ; 15734110 (ISSN) Nazir, M. S ; Ahmad, S ; Tahir, Z ; Ul Hassan, S ; Ali, Z ; Akhtar, M. N ; Azam, K ; Abdullah, M. O ; Sharif University of Technology
    Bentham Science Publishers  2021
    Background: Diesel mainly consists of paraffin and thio-aromatic compounds. Sulfur present in diesel exhaust is the major challenge for oil refineries. Sulfur is an oxidizing element that discharges as acute pollutant in the environment, having adverse effects on human and animal life. Introduction: The scope of this review paper is to discuss and highlight the recent advancements in the process of desulfurization of diesel oil to explore the less energy-intensive and more economical process. Methods: Recently, different techniques are widely used for desulfurization of diesel oil to remove sulfur containing compounds from diesel. These techniques mainly involve hydrodesulfurzation,... 

    Desulfurization of Tabas coal with microwave irradiation/peroxyacetic acid washing at 25, 55 and 85 °C

    , Article Fuel ; Volume 83, Issue 7-8 , 2004 , Pages 943-949 ; 00162361 (ISSN) Jorjani, E ; Rezai, B ; Vossoughi, M ; Osanloo, M ; Sharif University of Technology
    Tabas coal sample from Iran was desulfurized with combination of microwave irradiation and peroxyacetic acid washing in a batch reactor. The effect of irradiation time and power, peroxyacetic acid reaction time and temperature and particle size on reduction of sulfur was investigated. For microwaved/acid washed samples, depending on desulfurization conditions, the reduction in pyritic, organic and total sulfur ranged from 26 to 91, 2.6 to 38.4 and 17 to 65%, respectively. Microwave irradiation had positive effect on desulfurization with peroxyacetic acid. For <300 μm size fraction, after irradiation, the reduction enhanced from 49.9 to 86.6% in pyritic sulfur, 23.8 to 35% in organic sulfur... 

    Synthesis and Evaluation of Nanostructured Magnetic Photocatalysts for Oxidation Desulfurization of Liquid Fuels

    , M.Sc. Thesis Sharif University of Technology Salehian, Siamak (Author) ; Ghotbi, Sirous (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
    In recent decades, desulfurization processes have become necessary to reduce environmental pollution due to fuel sulfur emissions. In this research, in order to photocatalytic oxidation desulfurization of liquid fuel, a model fuel (normal octane) under visible light irradiation of 250 W sodium lamp, using H2O2 oxidant and methanol solvent in the presence of BMO/Fe@MIL(x%) composite. BMO and Fe@MIL were investigated. From the tests, X-ray diffraction, scanning and transmission electron microscope imaging, absorption and desorption of nitrogen gas, infrared spectrometer-Fourier transform, visible-ultraviolet reflection spectroscopy, optical radiation spectroscopy and vibration magnetometer in... 

    Electrochemical oxidative desulfurization for high sulfur content crude gas-oil

    , Article Separation and Purification Technology ; Volume 248 , 2020 Tavan, Y ; Shahrokhi, M ; Farhadi, F ; Sharif University of Technology
    Elsevier B.V  2020
    Presence of sulfur components in liquid fuels should be controlled due to environmental issues and process considerations. In order to decrease the level of sulfurous compounds in crude gas-oil with 5750 ppmw sulfur, electrochemical oxidative desulfurization has been investigated over electrodes of copper and stainless steel because of their easy operation and mild process conditions. In this research, the effects of stirring rate, temperature, applied potential, sodium hydroxide addition as electrolyte media and water volume have been examined on the sulfur removal efficiency. The results show that electrical conductivity of gas-oil sharply increases with addition of electrolyte up to 613... 

    The Investigation of Adsorption Desulfurization of Ethyl Mercaptan by Microfluidic Technology

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Ayda (Author) ; Mohammadi, Ali Asghar (Supervisor)
    In recent years, desulfurization has received much attention due to its devastating environmental effects. The existence of sulfur compounds has effects such as corrosion, poisoning of catalysts, reduction of heat of combustion and reduction of price. Sulfur compounds in hydrocarbon fuels also produce sulfur oxides caused by combustion then they enter the atmosphere, and cause acid rain. Acid rain dissolves building materials, poisons lakes, and destroys forests. Therefore, removing sulfur or converting it to less harmful substances is one of the most important processes in refineries. The method studied in this research is the use of adsorption desulfurization method by microchannel which... 

    Oxidation Desulfurization of Liquid Fuels Using TiO2-based Photocatalysts

    , M.Sc. Thesis Sharif University of Technology Ostovar, Abdollah (Author) ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
    Due to the increasing consumption of fuel, the use of new methods with high efficiency to remove sulfur from fossil fuels is felt more than ever. Hydrogenation and oxidation of sulfur organic matter, such as thiophenes, is an old method of desulfurization of liquid fuels. Using a photocatalyst, everything can be done in an environment that is very low cost. In this study, the photocatalytic elimination of dibenzothiophene was investigated. For this purpose, carbon-doped thiamine dioxide was used as the photocatalytic base, which is synthesized by hydrothermal method. This method is the same source of titanium and carbon. To increase the performance of the catalyst, platinum metal was loaded... 

    Oxidative desulfurization of Non-hydrotreated kerosene using hydrogen peroxide and acetic acid

    , Article Chinese Journal of Chemical Engineering ; Volume 17, Issue 5 , 2009 , Pages 869-874 ; 10049541 (ISSN) Molaei Dehkordi, A ; Sobati, M. A ; Nazem, M. A ; Sharif University of Technology
    The oxidative desulfurization of a real refinery feedstock (i.e., non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied. The influences of various operating parameters including reaction temperature (T), acid to sulfur molar ratio (nacid/nS), and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated. The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal. Moreover, there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS8 and 23 for the reaction temperatures of 25... 

    Microfluidics Desulfurization of Hydrocarbons Components

    , M.Sc. Thesis Sharif University of Technology Ranjbar Koleibi, Amir (Author) ; Mohammadi, Aliasghar (Supervisor) ; Kazemeini, Mohammad (Supervisor)
    Microfluidic is a science and technology in which they study the behavior of fluids, control them and design devices or systems with dimensions of tens to hundreds of micrometers. The technology has the ability to design and manufacture macro-scale and micro-scale equipment, such as micro-pumps, micro-valves, micro-filters, micro-mixers, micro-reactors, and other equipment. The benefits of this technology include the use of low sample size, low waste of energy, low power consumption, short response time, high system performance, portability and performance of several operating phases in a compressed piece such as production, isolation and analysis. Also, the very low amount of chemicals and... 

    Theoretical and Practical Effects of Ultrasound on Desulfurization Process

    , M.Sc. Thesis Sharif University of Technology Makarem, Mohammad Amin (Author) ; Ghotbi, Siroos (Supervisor) ; Taghikhani, Vahid (Co-Advisor) ; Badakhshan, Amir (Co-Advisor)
    In past three decades, use of crude oil’s derivatives increased dramatically. The critical environmental condition of today’s world, which majorly caused by unclean fuels, forces governments to legislate new rules to increase quality of fuels. These rules force refinery industries to produce clean fuels. One of the main processes in producing clean fuels is Desulfurization process. For fuel desulfurization there are different kinds of processes like HydroDesulfruization, Oxidative Desulfurization, Bio-desulfurization, etc. From these processes Hydro-desulfurization is the conventional process for desulfurization. Because of significant problems of this process, like high operational cost,... 

    Using Molecular Dynamics Simulation for Investigation of Sulfuric Compounds Adsorption on Zeolite

    , M.Sc. Thesis Sharif University of Technology Ramezani Shabolaghi, Kianoush (Author) ; Mohammadi, Aliasghar (Supervisor)
    There are different sulfur compounds in the crude oil, and after combustion all of these sulfuric compounds produce sulfur dioxide, this sulfur dioxide cause acid rain, deactivation of catalysts and also environmental bad effects. So the amount of sulfur that is released should be controlled and this is done by removing sulfuric compounds before combustion. zeolites as adsorbent of sulfuric compounds has been used widely by researches and had given good results. molecular dynamics simulation as an effective way for describing the behavior of these compounds in the molecular level and in scales of angstrom has been used and the effect of van der waals and electrostatic forces between sorbates... 

    Oxidative Desulfurization of Gas Condensate

    , M.Sc. Thesis Sharif University of Technology Keshavarzi, Samaneh (Author) ; Seifkordi, Ali Akbar (Supervisor) ; Bazmi, Mansour (Co-Advisor) ; Ghaedian, Maryam (Co-Advisor)
    Due to increasing environmental concern, special interest has been paid to reduction of organosulfur compounds in transportaion fuels. The sulfur- containing compounds are converted into sulfur oxide, i.e, SOx , during combustion, which is a major source of acid rain and air pollution.Gas condensate is a mixture consisting primarily of pentanes and heavier hydrocarbons which is recovered as a liquid from natural gas. It is a proper hydrocarbon source for producing gasoline, kerosene and gas oil in refineries. In this reseach a gas condensate was used as feedstock for studing oxidative desulfurization (ODS). The influence of various parameters of desulforization including the reaction... 

    Extraction of Oxidized Sulfur Compounds of Gas Oil from Oxidation Desulfurization Reactor Products

    , M.Sc. Thesis Sharif University of Technology Heidari, Mahsa (Author) ; Sayf Kordi, Ali Akbar (Supervisor) ; Ghaedian, Maryam (Supervisor)
    It is well known that sulfur removal from petroleum is necessary for both industrial and environmental reasons. Sulfur in petroleum products corrodes parts of internal combustion engines and refineries due to the formation of sulfur oxyacids and causes major air pollution and acid rain due to exhaust from diesel engines and emission of sulfur oxides. Hydrodesulfurization (HDS), biodesulfurization (BDS), extraction by ionic-liquids (ILs), selective adsorption, alkylation desulfurization and oxidative desulfurization (ODS) are some methods, can be effective in removal of sulfur compounds. Among these new processes, ODS appears to be particularly promising and is currently receiving increasing... 

    Extraction conditions for removal of oxidized sulfur compounds in gas oil

    , Article Korean Journal of Chemical Engineering ; Volume 30, Issue 3 , 2013 , Pages 700-705 ; 02561115 (ISSN) Heidari, M ; Safekordi, A. A ; Ghaedian, M ; Shafeghat, A ; Sharif University of Technology
    An experimental study was conducted to investigate the extraction of oxidized sulfur compounds from gas oil. Solvents used for this purpose included acetone, acetonitrile, methanol and propanol. The effect of solvent concentration, solvent to gas oil ratio, temperature, time and number of stages was studied. To select the best solvent and conditions for extraction, two criteria were considered: high desulfurization and more hydrocarbon recovery. Results showed that extraction time and temperature have no significant effect. Methanol for low ability of extraction of oxidized sulfur compounds and propanol for low hydrocarbon recovery were excluded from further experiments. After the tests, the... 

    Desulfurization of high sulfur petroleum coke by molten caustic leaching

    , Article Egyptian Journal of Petroleum ; Volume 28, Issue 2 , 2019 , Pages 225-231 ; 11100621 (ISSN) Askari, H ; Khorasheh, F ; Soltanali, S ; Tayyebi, S ; Sharif University of Technology
    Egyptian Petroleum Research Institute  2019
    Desulfurization by molten caustic leaching (MCL) at 400–500 °C has been investigated in order to reduce the sulfur content of petroleum coke. Effective parameters on desulfurization of petroleum coke, other than temperature, include alkali to feed (petroleum coke) mass ratio, time and mesh size in the ranges of 0.5–1.5, 1–3 h and 200–600 µm, respectively. In this work, petroleum coke desulfurization conditions using solid KOH have been studied. Maximum petroleum coke desulfurization by MCL method has been obtained by Taguchi L9 design using alkali to feed mass ratio of 1, temperature of 600 °C, time of 2 h and mesh size of 200 µm. The changes in the main groups on the coke surface have been... 

    Highly efficient SO3Ag-functionalized MIL-101(Cr) for adsorptive desulfurization of the gas stream: Experimental and DFT study

    , Article Chemical Engineering Journal ; Volume 363 , 2019 , Pages 73-83 ; 13858947 (ISSN) Pourreza, A ; Askari, S ; Rashidi, A ; Seif, A ; Kooti, M ; Sharif University of Technology
    Elsevier B.V  2019
    In this research, an adsorbent with manifold interplay sites for the adsorption of sulfur components is developed in a silver ion functionalized Cr3+ based metal-organic framework (MIL-101(Cr)-SO3Ag). The adsorption performance of MIL-101(Cr), MIL-101(Cr)-SO3H, and MIL-101(Cr)-SO3Ag was evaluated in dynamic adsorption system in terms of its adsorption capacity. MIL-101(Cr)-SO3Ag could interact with H2S through multiple ways which performed about 4 times higher adsorption capacity (96.75 mg/g) rather than MIL-101(Cr); further, the high adsorption capacity of MIL-101(Cr)-SO3Ag was almost unchanged after five successive adsorption–desorption cycles, making it a potential adsorbent for an... 

    Adsorptive desulfurization of wild naphtha using magnesium hydroxide-coated ceramic foam filters in pilot scale: Process optimization and sensitivity analysis

    , Article Chemical Engineering and Processing - Process Intensification ; Volume 152 , 2020 Salehi, E ; Askari, M ; Afshar, S ; Eidi, B ; Aliee, M. H ; Sharif University of Technology
    Elsevier B.V  2020
    Ultra-deep desulfurization for production of clean fuels is of great significance from environmental outlook. In this paper, adsorptive desulfurization (ADS) of wild naphtha was investigated in pilot scale using Mg(OH)2-impregnated aluminosilicate ceramic foam filters (ASCFs) as adsorbent. Effects of four operating parameters including temperature, pressure, adsorption bed length and initial sulfur concentration on sulfur removal efficiency of the process were studied via central composite design of experiment methodology. Sobol's sensitivity analysis was employed to quantitatively determine the impacts of the operating parameters on the removal performance of the separation system. The... 

    Oxidative desulfurization of a model liquid fuel over an rGO-supported transition metal modified WO3 catalyst: Experimental and theoretical studies

    , Article Separation and Purification Technology ; Volume 269 , 2021 ; 13835866 (ISSN) Hasannia, S ; Kazemeini, M ; Seif, A ; Rashidi, A ; Sharif University of Technology
    Elsevier B.V  2021
    The XW/rGO compounds (XW = Co or Ni modified WO3) have has been utilized as catalysts in the oxidative desulfurization (ODS) process of a liquid model fuel containing dibenzothiophene (DBT). Various characterization methods were carried out to complete evaluations of the prepared catalysts. Moreover, using the GC–MS method, it became clear that the final product of the process was dibenzothiophene sulfone (DBTO2). Furthermore, results showed that under the optimized conditions (oxidant to substrate molar ratio = 6, 75 °C and catalyst to substrate molar ratio = 0.08), the DBT content of a model fuel was declined by 100% only within a reaction duration time of 45 min using the CoW (20)/rGO... 

    Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part I: Flask experiments

    , Article Fuel ; Volume 85, Issue 17-18 , 2006 , Pages 2555-2560 ; 00162361 (ISSN) Mousavi, S. M ; Yaghmaei, S ; Salimi, F ; Jafari, A ; Sharif University of Technology
    Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans has proved to be a significant step in the bioleaching of sulfide minerals and the treatment of acid mine drainage. The same bioreaction also has beneficial applications in the desulphurization of coal and removal of hydrogen sulfide from gaseous effluents. In this research, the effects of some process variables such as pH, temperature, elemental sulfur, amount of initial ferrous and magnesium ions on oxidation of ferrous sulfate by a native A. ferrooxidans, which was isolated from a chalcopyrite concentrate, were investigated. All experiments carried out in shake flasks at 33 °C that was obtained as optimum... 

    Oxidative desulfurization of simulated light fuel oil and untreated kerosene

    , Article Fuel Processing Technology ; Volume 90, Issue 3 , 2009 , Pages 435-445 ; 03783820 (ISSN) Dehkordi, A.M ; Kiaei, Z ; Sobati, M.A ; Sharif University of Technology
    An experimental investigation was conducted on the oxidative desulfurization of model sulfur compounds such as dibenzothiophene and benzothiophene in toluene as a simulated light fuel oil with a mixture of hydrogen peroxide as the oxidant and various acids as the catalyst. The influences of various parameters including reaction temperature (T), acid to sulfur molar ratio (Acid/S), oxidant to sulfur molar ratio (O/S), type of acid, and the presence of sodium tungstate and commercial activated carbon as a co-catalyst on the fractional conversion of the model sulfur compounds were investigated. The experimental data obtained were used to determine the reaction rate constant of the model sulfur... 

    Exact Dynamic Simulation and Control for Hydrotreating Unit of Tehran Refinery

    , M.Sc. Thesis Sharif University of Technology Shabanian, Jaber (Author) ; Bozorgmehri, Ramin (Supervisor)
    Since steady state behavior of a plant is affected by the change of various inputs to the plant, the transient behavior of the chemical plants are also very important in their general performance. On the other hand, catalytic hydrotreating is one of the most important processes in crude oil refining process in many aspects such as economical, technical and environmental. Thus, the goal of this project was dynamic simulation and control of catalytic hydrotreating unit (UNIFINER Unit) of Tehran Refinery with using the HYSYS software. To fulfill this target, data that were necessary for simulation were gathered from Unifiner unit of Tehran refinery at first. Then, steady state simulation of the...