Sulfur Compounds In Petroleum Research Articles

Speciation and molecular characterization of thiophenic and sulfide compounds in petroleum by sulfonation and methylation followed by electrospray mass spectrometry.

Thiophenes and sulfides are the dominant sulfur-containing compounds in petroleum and have been widely ofconcern in the fields of petroleum refining and geochemistry. In this study, a novel approach was developed for selective separation and characterization of petroleum-derived thiophenic and sulfide compounds. Thiophenic compounds were selectively converted to sulfonates in the presence of vitriolic acid and can be characterized by negative ion electrospray mass spectrometry. Thiophenic sulfonates were further separated from the oil by silica chromatography and enabled the molecular characterization of sulfides in the residual oil. Various model sulfur compounds and a vacuum gas oil were used to validate the method; thiophenic and sulfide biomarker compounds in a well-documented crude oil were selectively characterized. The results indicate that the approach is feasible for molecular characterization of thiophenic and sulfide compounds, which is complementary to recently developed methods for separation and/or ionization of sulfur compounds in petroleum.

Review on Sulfur Compounds in Petroleum and Its Products: State-of-the-Art and Perspectives

Review on Sulfur Compounds in Petroleum and Its Products: State-of-the-Art and Perspectives

Characterization of Desulfinase for the Removal of Recalcitrant Sulfur Compounds in Petroleum

Biodesulfurization provides a method to remove the sulfur from organosulfur compounds found in petroleum. This multi‐step pathway is able to remove sulfur from dibenzothiophene (DBT), one of the most recalcitrant compounds found in petroleum and crude oil. A critical enzyme in this pathway is an aromatic desulfinase (DszB) that catalyzes the final rate‐limiting step of the desulfurization. The DszB enzyme from Nocardia asteroides A3H1 was overexpressed in E. coli, purified using Ni2+‐affinity chromatography and characterized kinetically. Kinetic assays revealed a sigmoidal response when the velocity was plotted against substrate concentration, calling into question the monomeric structure of the enzyme previously reported by crystallography studies. Size exclusion chromatography and cross‐linking experiments were conducted to further investigate the oligomerization of HPBS desulfinase. Attempts to further purify the enzyme using Co2+‐affinity chromatography provided further evidence that under certain conditions DszB may exhibit cooperativity.Support or Funding InformationJMU Department of Chemistry and Biochemistry Dr. Linette M. Watkins NSF Grant No. CHE‐1757874

Identification of Artifacts in the Methylation Process of Sulfur Compounds in Petroleum

Methylation of sulfides and thiophenes into methyl sulfonium salts for electrospray ionization (ESI) mass spectrometry analysis has been a widely used approach for molecular characterization of sul...

Optimization of Substrate and Starter Cell Concentrations for Dibenzothiopene Biodegradation by Indigeneous Marine Bacteria <i>Mauricauda olearia</i> LBF-1-0009, <i>Alcanivorax xenomutants</i> LBF-1-0018, and <i>Stakelama pacifica</i> LBF-1-0031

Dibenzothiophene (DBT) and its derivatives have been widely used as model organic sulfur compounds in petroleum, included their biodegradation process. The abilities of microorganisms to degrade pollutants are significantly influenced by various factors such as microbial species, nutrients and environmental parameters. In this research, we carried out further study to determine optimal condition for DBT biodegradation regarding with substrate and strains cell concentration by several indigenous marine bacteria from Indonesia. These three isolates were belong to Mauricauda olearia, Alcanivorax xenomutants, and Stakelama pacifica, with homology result 99% each. Optimal dibenzothiophene as substrate reached by all isolates is 100 ppm, while cell concentration or microbial numbers that gave highest growth for all isolates is 20 based on conversion of OD600 nm measurement.

Optimization of Substrate and Starter Cell Concentrations for Dibenzothiopene Biodegradation by Indigeneous Marine Bacteria Mauricauda olearia LBF-1-0009, Alcanivorax xenomutants LBF-1-0018, and Stakelama pacifica LBF-1-0031

Dibenzothiophene (DBT) and its derivatives have been widely used as model organic sulfur compounds in petroleum, included their biodegradation process. The abilities of microorganisms to degrade pollutants are significantly influenced by various factors such as microbial species, nutrients and environmental parameters. In this research, we carried out further study to determine optimal condition for DBT biodegradation regarding with substrate and strains cell concentration by several indigenous marine bacteria from Indonesia. These three isolates were belong to Mauricauda olearia, Alcanivorax xenomutants, and Stakelama pacifica, with homology result 99% each. Optimal dibenzothiophene as substrate reached by all isolates is 100 ppm, while cell concentration or microbial numbers that gave highest growth for all isolates is 20 based on conversion of OD600 nm measurement.

An ultrahigh-resolution mass spectrometry study of ozonation products of petroleum sulfur compounds

Potential use of ultrahigh-resolution mass spectrometry for determination of sulfur-containing components of petroleum before and after ozonation has been described. The chemical composition of the petroleum before and after ozonation has been determined using a Fourier transform ion-cyclotron mass spectrometer with soft ionization techniques: atmospheric-pressure photoionization and positive- or negative-ion electrospray ionization. The article presents the main trends of change in the composition of petroleum sulfur components in the ozonation process as revealed on the basis of ultrahigh-resolution mass spectra.

Synergic Effects of Photocatalytic and Enzymatic Degradation of Dibenzothiophene by Titania Nanolayer Coated on Glass and Intracellular Enzymes

To remove sulfur compounds in petroleum, the authors prepared intracellular enzymes that could degrade dibenzothiophene (DBT) in the presence of titania nanolayer coated on glass as photocatalyst. The titania nanolayer was synthesized by the sol–gel method coated on glass by doctor blade method using titanium tetra isopropoxide (TTIP) as precursor and characterized by Fourier transmission infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) techniques, atomic force microscopy (AFM), and UV–Vis spectroscopy (DRS). The enzymatic action of the intracellular enzymes in aqueous media containing a titania was evaluated as a feasible system for the degradation of dibenzothiophene as a model sulfur compound. Dibenzothiophene was degraded to a large extent after a very short period of 20 min. Intracellular enzymes in the presence of titania nanolayer possess synergic effect in photocatalytic and enzymatic degradation of dibenzothiophene by titania nanolayer coated on glass using doctor blade method and intracellular enzymes.

ChemInform Abstract: Sulfur Compounds of Petroleum. Part 12. Synthesis of b,d-Anellated Diindanothiophenes (VI) and (VII).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Characterization of Sulfide Compounds in Petroleum: Selective Oxidation Followed by Positive-Ion Electrospray Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

A novel analytical method for identifying sulfides in petroleum and its fractions was developed. Sulfides in petroleum were selectively oxidized into sulfoxides using tetrabutylammonium periodate (TBAPI) and identified by positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). A variety of model sulfur compounds were examined to evaluate the selective oxidization and ionization efficiencies for sulfur compounds in petroleum. Two fractions, straight-run diesel and saturates of Athabasca oilsands bitumen were investigated using this approach. The oxidization process was highly selective for sulfides from thiophenes and aromatic hydrocarbons. Oxidation generated sulfoxides were ionized by positive-ion ESI and analyzed by FT-ICR MS. Mass spectra revealed the composition characteristics of sulfides in the diesel by contrasting the double bond equivalence (DBE) and carbon number distribution of sulfur compounds before and after oxidation. The abundant sulfides in the straight run diesel and saturates fraction of oilsands bitumen had DBE values of 1-3 and 1-4, respectively.

Electrochemical determination of elemental sulfur in Brazilian naphtha: method and validation

Sulfur compounds in petroleum have caused several problems such as corrosion of equipment, lack of high quality final products, and emission of toxic gases into the environment. Elemental sulfur can increase these problems, since small amounts of it turn mercaptans into potential corrosion agents. This paper describes the applicability of a voltammetric method to quantify elemental sulfur in Brazilian naphtha samples. Elemental sulfur was quantified in synthetic and real samples using square wave voltammetry and a hanging mercury drop electrode. The method was found to have low limits of detection (0.003 mg L−1) and quantification (0.009 mg L−1) and a good recovery range (94.0–108.6%). This voltammetric method has potential for use in elemental sulfur determination in naphtha samples containing mercaptans and aliphatic and aromatic disulfides.

A simulation on the formation of organic sulfur compounds in petroleum from thermochemical sulfate reduction

Thermochemical reduction of magnesium sulphate with n-pentane was carried out in an autoclave in the presence of water at high temperature and pressure to simulate the origination of organic sulfur compounds in petroleum from thermochemical sulphate reduction (TSR). The products of 3 phases (gas, oil, and solid) were analyzed by some advanced analytical methods including gas chromatography, microcoulometry, FT-IR, and X-ray diffraction. Results show that the TSR reaction occurred at 425–525°C with MgO, C, H 2S, CO 2, and a series of organic sulfur compounds such as mercaptans, sulfoethers, and thiophenes as the main products. The reaction kinetics was studied and the calculated activation energy is 58.0 kJ/mol.

Biodesulfurization of Dibenzothiophene by a Newly Isolated Thermophilic Bacteria Strain

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 sulfur 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 products because it keeps the remaining hydrocarbon molecules fully active as energy sources without any loss of their thermal units. At the next step, some physical and chemical properties of main culture were optimized as follows: 6gr/lit glucose, 4gr/lit ammonium chloride, 0.15 mM DBT, pH= 7 and temperature= 45°C. During 6 days, growing cells of this microorganism can convert 87.5% of DBT in 250 ml flask. At last, kinetic analysis has been done and Michaelis-Menten equation qualified. Equation parameters Vmax and KM calculated and data led to 0.548 mM h −1 and 0.458 mM, respectively.

Removal of Dibenzothiophene from the Simulated Petroleum by γ-Irradiation Induced Reaction

A novel method for the removal of sulfur compounds in petroleum was put forward and investigated on the basis of the radiochemical reaction induced by y irradiation. Dibenzothiophene (DBT) dissolved in dodecane was employed as the simulated petroleum. The results showed that the removal efficiency of DBT was about 33% when the radiation dose was 185 kGy. The apparent reactions for the removal of DBT were presumed, and the corresponding kinetics equation was deduced and proven experimentally. Meanwhile, some methods were preliminarily used to improve the removal of DBT in the presence of y irradiation at room temperature. Among which, the mixture of hydrogen peroxide (H 2 O 2 ) and acetic acid (HAC) appeared to be synergic to the radiation removal of DBT. Also, Cobalt-oxide showed significant promotion to the removal of DBT under the irradiated situation, and the removal efficiency increased by over 40% compared with radiation only.

Isolation and characterization of a sulfur-oxidizing chemolithotroph growing on crude oil under anaerobic conditions.

Molecular approaches have shown that a group of bacteria (called cluster 1 bacteria) affiliated with the epsilon subclass of the class Proteobacteria constituted major populations in underground crude-oil storage cavities. In order to unveil their physiology and ecological niche, this study isolated bacterial strains (exemplified by strain YK-1) affiliated with the cluster 1 bacteria from an oil storage cavity at Kuji in Iwate, Japan. 16S rRNA gene sequence analysis indicated that its closest relative was Thiomicrospira denitrificans (90% identity). Growth experiments under anaerobic conditions showed that strain YK-1 was a sulfur-oxidizing obligate chemolithotroph utilizing sulfide, elemental sulfur, thiosulfate, and hydrogen as electron donors and nitrate as an electron acceptor. Oxygen also supported its growth only under microaerobic conditions. Strain YK-1 could not grow on nitrite, and nitrite was the final product of nitrate reduction. Neither sugars, organic acids (including acetate), nor hydrocarbons could serve as carbon and energy sources. A typical stoichiometry of its energy metabolism followed an equation: S(2-) + 4NO(3)(-) --> SO(4)(2-) + 4NO(2)(-) (Delta G(0) = -534 kJ mol(-1)). In a difference from other anaerobic sulfur-oxidizing bacteria, this bacterium was sensitive to NaCl; growth in medium containing more than 1% NaCl was negligible. When YK-1 was grown anaerobically in a sulfur-depleted inorganic medium overlaid with crude oil, sulfate was produced, corresponding to its growth. On the contrary, YK-1 could not utilize crude oil as a carbon source. These results suggest that the cluster 1 bacteria yielded energy for growth in oil storage cavities by oxidizing petroleum sulfur compounds. Based on its physiology, ecological interactions with other members of the groundwater community are discussed.

Degradation of Dibenzothiophene by Sulfate-Reducing Bacteria Cultured in the Presence of Only Nitrogen Gas.

To remove sulfur compounds in petroleum, we isolated sulfate-reducing bacteria that could degrade dibenzothiophene in the presence of only nitrogen gas. Among the 19 strains isolated, some could grow in the presence of 10% (v/v) kerosene and of which two strains were identified as Desulfomicrobium escambium and Desulfovibrio longreachii. Gas chromatography of the ethyl-acetate extract of bacterial cultures, in which 10% or more of the dibenzothiophene initially present was degraded, gave five unknown peaks as the presumable degradation products. Thus, desulfurization of dibenzothiophene could be carried out without oxygen or hydrogen in a pathway different from the anaerobic one already reported, in which biphenyl is detected as the main product.

Degradation of dibenzothiophene by sulfate-reducing bacteria cultured in the presence of only nitrogen gas

To remove sulfur compounds in petroleum, we isolated sulfate-reducing bacteria that could degrade dibenzothiophene in the presence of only nitrogen gas. Among the 19 strains isolated, some could grow in the presence of 10% (v/v) kerosene and of which two strains were identified as Desulfomicrobium escambium and Desulfovibrio longreachii. Gas chromatography of the ethyl-acetate extract of bacterial cultures, in which 10% or more of the dibenzothiophene initially present was degraded, gave five unknown peaks as the presumable degradation products. Thus, desulfurization of dibenzothiophene could be carried out without oxygen or hydrogen in a pathway different from the anaerobic one already reported, in which biphenyl is detected as the main product.

SULFUR FILTER BY INTERMETALLIC MEDIA

ABSTRACT Two types of filter are developed. One is for the removal of sulfur compounds in petroleum and its derived products. The other is for upgrading, which is to lower the amount of asphaltene. Although research in selectivity and life cycle estimation of intermetallic media is still continuing, the mechanisms behind this technology are based upon the concept of nanotechnology and the principle of membrane mimetic chemistry.

Microbial desulfurization of organic sulfur compounds in petroleum.

Sulfur removal from petroleum is important from the standpoint of the global environment because the combustion of sulfur compounds leads to the production of sulfur oxides, which are the source of acid rain. As the regulations for sulfur in fuels become more stringent, the existing chemical desulfurizations are coming inadequate for the "deeper desulfurization" to produce lower-sulfur fuels without new and innovative processes. Biodesulfurization is rising as one of the candidates. Several microorganisms were found to desulfurize dibenzothiophene (DBT), a representative of the organic sulfur compounds in petroleum, forming a sulfur-free compound, 2-hydroxybiphenyl. They are promising as biocatalysts in the microbial desulfurization of petroleum because without assimilation of the carbon content, they remove only sulfur from the heterocyclic compounds which is refractory to conventional chemical desulfurization. Both enzymological and molecular genetic studies are now in progress for the purpose of obtaining improved desulfurization activity of organisms. The genes involved in the sulfur-specific DBT desulfurization were identified and the corresponding enzymes have been investigated. From the practical point of view, it has been proved that the microbial desulfurization proceeds in the presence of high concentrations of hydrocarbons, and more complicated DBT analogs are also desulfurized by the microorganisms. This review outlines the progress in the studies of the microbial desulfurization from the basic and practical point of view.

Structural characterization of sulfur compounds in petroleum by S-methylation and carbon-13 NMR spectroscopy. [Erratum to document cited in CA120:58049

Structural characterization of sulfur compounds in petroleum by S-methylation and carbon-13 NMR spectroscopy. [Erratum to document cited in CA120:58049