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dibenzothiophene
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Biodesulfurization of dibenzothiophene by a newly isolated thermophilic bacteria strain
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 25, Issue 3 , 2006 , Pages 65-72 ; 10219986 (ISSN) ; Yaghmaei, S ; Mousavi, S.M ; Jadidi, A.R ; Sharif University of Technology
2006
Abstract
Microbiological analyses of soil chronically exposed to petroleum complex compounds of some oil springs in south of Iran resulted in isolation and purification of a new native thermophilic strain which is capable to desulfurize petroleum sulfur compounds by 4-S mechanism. Dibenzothiophene (DBT) was selected as a complex sulfiir compound model and many experiments were done to identify the metabolic pathway. The results of these experiments show that DBT is ultimately converted to 2-hydroxybiphenyl (2-HBP) and sulfite. This is a special metabolic pathway in that there is no effect on the carbon skeleton of organic compounds and would be ideal for desulfurization to upgrade the petroleum...
Selective desulfurization of dibenzothiophene by newly isolated Corynebacterium sp. strain P32C1
, Article Biochemical Engineering Journal ; Volume 5, Issue 1 , 2000 , Pages 11-16 ; 1369703X (ISSN) ; Kheirolomoom, A ; Vossoughi, M ; Tanaka, E ; Katoh, S ; Sharif University of Technology
2000
Abstract
Corynebacterium sp. strain P32C1 was selected from 30 strains isolated from soil samples of various areas in Iran on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. During 27 h of cultivation in a jar-fermentor, DBT with an initial concentration of 0.25 mM was completely converted to 2-hydroxybip henyl (2HBP). Concentration change of 2'-hydroxybiphenyl-2-sulfinate (HBPS) during cultivation showed the general characteristics of reactions in series, DBT → HBPS → 2HBR. With resting cells prepared in late exponential phase, DBT of 0.5 mM was completely converted to 2HBP during 30 min, and the maximum specific production rate of 2HBP was 37 mmol/(kg dry...
Photocatalytic degradation of dibenzothiophene using La/PEG-modified TiO2 under visible light irradiation
, Article Research on Chemical Intermediates ; Jan , 2014 , pp. 1-17 ; Vossoughi, M ; Feilizadeh, M ; Zakeri, S. M. E ; Mohammadi, M. M ; Rashtchian, D ; Yoosefi Booshehri, A ; Sharif University of Technology
Abstract
While the photocatalytic degradation of various organic compounds under UV light irradiation has been widely investigated, visible-light-induced photocatalytic degradation of low levels of pollutants such as dibenzothiophene (DBT) is occasionally reported. In the present work, lanthanide/polyethylene glycol-modified TiO2 (La/PEG/TiO2) has been successfully synthesized by a sol-gel method. The photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis diffusive reflectance spectroscopy, and energy dispersive X-ray analysis. Moreover, the photocatalytic degradation of DBT under visible light irradiation is investigated for the...
Simulation of Hydrodesulfurization Plant
, M.Sc. Thesis Sharif University of Technology ; Fahadi, Fathollah (Supervisor)
Abstract
Sulfur components are one of the most important impurities in various petroleum fractions that cause many problems in refining and consumption. In this thesis, hydrodesulfurization process, which has an economical and environmental especial position in petroleum and other related industries, has been discussed. In hydrodesulfurization process, under specific operation condition, sulfur components are converted catalytically to the H2S in a fixed bed reactor. In this study dibenzothiophene, which is one of the most strength and complex sulfur components, is considered as the base component. A Langmuir-Hinshelwood kinetic equation is used to describe the reaction by using the commercial...
Studies on DBT Removal from Compositional Oil Model Using CNT
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manoochehr (Supervisor) ; Aalemzadeh, Iran (Supervisor)
Abstract
In this research, carbon nanotubes (CNTs) and CNT coated by titanium dioxide (TiO2) were used as adsorbents for desulfurization. Photocatalytic oxidation by titanium dioxide Degussa P-25 nanoparticles (as photocatalyst) immobilized on a porous and low-density support called “perlite” and CNT/TiO2 was perused. TiO2-coatings were prepared by liquid phase deposition method.This is a wet process for the formation of metal oxide thin films on substrates. The coating of nanotubes with TiO2 was confirmed by IR and EDAX and morphological properties were observed by SEM analysis.The physical properties of adsorbents were determine using BET.Dibenzothiophene (DBT)dissolved in acetonitrile was used as...
Biodesulfurization of Light Fuel Oil
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fatollah (Supervisor) ; Molaei, Asghar (Supervisor) ; Arabeyan, Daruosh (Co-Advisor)
Abstract
Biological removal of sulfur compounds from petroleum is one of the major attractions of environmental technologies in the oil industry. Inefficient sulfur removal in refining processes causes sulfur oxides (SOx) production after combustion, which has adverse effects on the environment.Today the most common way to remove sulfur from crude oil is Hydrodesulfurization which has poor performance in removing some heterocyclic compounds such as thiophenes. Increase the amount of sulfur in the remaining oil reserves and the other hand, more stringent environmental regulations, has led researchers to development and invent new methods for desulfurization. Biological desulfurization is one of these...
Reduction of Sulfur Content of Model Feed by Oxidative Process in them Presence of Carbon Structures Based W-Mo Nanocatalysts
, Ph.D. Dissertation Sharif University of Technology ; Kazemini, Mohammad (Supervisor) ; Rashidi, Alimorad (Supervisor) ; Hajjar, Zeinab (Co-Supervisor)
Abstract
In this research, molybdenum and tungsten catalysts modified with cobalt and nickel on a carbon support have been synthesized and investigated in the oxidation desulfurization process. A model fuel was used to evaluate the synthesized catalysts. This model fuel was n-decane. dibenzothiophene was also used as a sulfur model. The synthesized catalysts were subjected to various analyzes such as XRD, FTIR, Raman, BET-BJH, NH3-TPD, TEM and ICP-OES for structural evaluation. On the other hand, synthetic parameters such as metal loading rate, molar or weight ratio of secondary metal (cobalt and nickel) to primary metal (molybdenum and tungsten) and molar ratio of citric acid to primary metal as...
Photocatalytic degradation of dibenzothiophene using La/PEG-modified TiO2 under visible light irradiation
,
Article
Research on Chemical Intermediates
;
Volume 41, Issue 7
,
July
,
2015
,
Pages 4151-4167
;
09226168 (ISSN)
; Vossoughi, M
; Feilizadeh, M
; Zakeri, S. M. E
; Mohammadi, M. M
; Rashtchian, D
; Yoosefi Booshehri, A
;
Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
While the photocatalytic degradation of various organic compounds under UV light irradiation has been widely investigated, visible-light-induced photocatalytic degradation of low levels of pollutants such as dibenzothiophene (DBT) is occasionally reported. In the present work, lanthanide/polyethylene glycol-modified TiO2 (La/PEG/TiO2 ) has been successfully synthesized by a sol-gel method. The photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis diffusive reflectance spectroscopy, and energy dispersive X-ray analysis. Moreover, the photocatalytic degradation of DBT under visible light irradiation is...
The oxidative desulfurization process performed upon a model fuel utilizing modified molybdenum based nanocatalysts: Experimental and density functional theory investigations under optimally prepared and operated conditions
, Article Applied Surface Science ; Volume 527 , 2020 ; Kazemeini, M ; Rashidi, A ; Seif, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
CoMo/reduced graphene oxide (rGO) catalyst was synthesized for the oxidative desulfurization process (ODS) of dibenzothiophene (DBT) in n-decane. Parameters including total metal (Co and Mo) loading, Co/Mo and CA (citric Acid)/Mo molar ratios were investigated toward achieving optimum conditions. The catalysts were characterized by the XRD, ICP, FTIR, Raman Spectroscopy, BET-BJH, NH3-TPD, XPS, and TEM methods. The product sulfur content was measured by the ICP-OES while the product was evaluated using FTIR and 1H NMR analyses. All experimental stages were designed using Design-Expert software. High BET area, acidity, uniform particle size, and Co-promoter played key roles in this...
Study of a newly isolated thermophilic bacterium capable of Kuhemond heavy crude oil and dibenzothiophene biodesulfurization following 4S pathway at 60°C
, Article Journal of Chemical Technology and Biotechnology ; Volume 83, Issue 12 , June , 2008 , Pages 1689-1693 ; 02682575 (ISSN) ; Shayegan, J ; Yaghmaei, S ; Alemzadeh, I ; Sharif University of Technology
2008
Abstract
Background: To meet stringent emission standards stipulated by regulatory agencies, the oil industry is required to bring down the sulfur content in fuels. As some compounds cannot be desulfurized by existing desulfurizing processes (such as hydrodesulfurization, HDS) biodesulfurization has become an interesting topic for researchers. Most of the isolated biodesulfurizing microorganisms are capable of desulfurization of refined products whose predominant sulfur species are dibenzothiophenes so biocatalyst development is still needed to desulfurize the spectrum of sulfur-bearing compounds present in whole crude. Results: The first desulfurizing bacterium active at 60 °C has been isolated,...
Biodesulfurization of dibenzothiophene by a newly isolated Rhodococcus erythropolis strain
, Article Bioresource Technology ; Volume 101, Issue 3 , 2010 , Pages 1102-1105 ; 09608524 (ISSN) ; Vosoughi, M ; Ziaee, A. A ; Sharif University of Technology
2010
Abstract
A new dibenzothiophene (DBT) desulfurizing bacterium was isolated from oil-contaminated soils in Iran. HPLC analysis and PCR-based detection of the presence of the DBT desulfurization genes (dszA, dszB and dszC) indicate that this strain converts DBT to 2-hydroxybiphenyl (2-HBP) via the 4S pathway. The strain, identified as Rhodococcus erythropolis SHT87, can utilize DBT, dibenzothiophene sulfone, thiophene, 2-methylthiophene and dimethylsulfoxide as a sole sulfur source for growth at 30 °C. The maximum specific desulfurization activity of strain SHT87 resting cells in aqueous and biphasic organic-aqueous systems at 30 °C was determined to be 0.36 and 0.47 μmol 2-HBP min-1 (g dry cell)-1,...
Kinetics of Adsorption of DBT Sulfur Containing Compound of Gasoline via Nanostructured Adsorbent
, M.Sc. Thesis Sharif University of Technology ; Sadrnezhad, Khatiboleslam (Supervisor)
Abstract
Based on the new standards, less than 10 ppm sulfur is allowed for the automotive fuels. This has led researchers to try improving the present conventional methods as well as seeking alternative routes for refinement of the petroleum products so much to comply with the requirements. Since thiophenic fragments such as dibenzothiophene (DBT) are the most durable sulfur compounds in the current hydrodisulfurization method, many studies have been conducted over recent years on how to remove these compounds. In this thesis, the desulfurization of dibenzothiophene from gasoline via adsorption method was studied. In order to carry out the adsorption process, a nanocomposite of graphitic-carbon...
Study and Improvement of Nano-photocatalytic Process Fordegradation of Chemical Contaminants
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Vosoughi, Manouchehr (Supervisor)
Abstract
In this thesis, photocatalytic oxidation as a potential method for the treatment of organic environmental contaminants is deeply investigated. While the photocatalytic degradation of various organic compounds under UV light irradiation has been widely investigated, visible-light-induced photocatalytic degradation of low-levels of the pollutants such as Dibenzothiophene (DBT) and 2-Nitrophenol (2-NP) are occasionally reported. In the present work, Lanthanide / Polyethylene glycol -modified TiO2 (La/PEG/TiO2) and Fe,Cu,S/TiO2 have been successfully synthesized by a sol–gel method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission...
Kinetic Evaluations, Economical and Scale-up Studies of the Co-Mo/Ɣ-Al2O3Catalyst for Hydrodesulfurization (HDS) Process
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Khorashe, Farhad (Supervisor)
Abstract
Sulfur compounds are very undesirable and result in Corrosion in metal equipment, air pollutions and poisoning of refinery Catalysts such as reforming Catalyst. Therefore, application of Hydrodesulfurization (HDS) process in order to decrease the amount of sulfur in petroleum cuts has a great importance. HDS process is the most usual and efficientmethod for sulfur removal. In this method sulfur compounds at vigorous operating conditions such as high temperature and pressure in the presence of catalyst react with hydrogen and produce hydrogen disulfide and hydrocarbon. Sulfided Co–Mo catalysts are widely used in this process.
The aim of this study is to prepare and improve CoMo/γ-Al2O3...
The aim of this study is to prepare and improve CoMo/γ-Al2O3...
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) ; Kazemeini, M ; Seif, A ; Rashidi, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
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...
Deep oxidative desulfurization via rGO-immobilized tin oxide nanocatalyst: Experimental and theoretical perspectives
, Article Advanced Powder Technology ; Volume 33, Issue 3 , 2022 ; 09218831 (ISSN) ; Kazemeini, M ; Hasannia, S ; Ekramipooya, A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this contribution, reduced grapheme oxides (rGO) with immobilized tin oxide (SnO2) nanocatalysts were synthesized via the Incipient Wetness Impregnation (IWI) method. To characterize the SnO2/rGO composites, several analyses including the; XRD, Raman, FTIR, ICP-OES, BET-BJH, XPS, TEM, and TPD were utilized. Then the effects of parameters including reaction time, total metal loading, and the initial sulfur concentration of model fuel in the dibenzothiophene (DBT) oxidation desulfurization process were evaluated. After determining the optimal conditions for the aforementioned parameters, the influences of 3 effective factors of the molar ratio of oxidant/substrate (O/S), the molar ratio of...
Oxidative desulfurization of simulated light fuel oil and untreated kerosene
, Article Fuel Processing Technology ; Volume 90, Issue 3 , 2009 , Pages 435-445 ; 03783820 (ISSN) ; Kiaei, Z ; Sobati, M.A ; Sharif University of Technology
2009
Abstract
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...