Improved methods for the selective isolation of the sulfide and thiophenic classes of compounds from petroleum

Payzant, J. D.; Mojelsky, Thomas W.; Strausz, O. P.

doi:10.1021/ef00016a004

Cited by 54 publications

(48 citation statements)

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“…Conversely, the thiophenes undergo photoinduced polymerization and thus contain up to 45 carbons (e.g., O 14 S 1 ) and can therefore incorporate more oxygen atoms (up to 17). It is important to note that previous studies have indicated that sulfides readily oxidize to sulfoxides (but not sulfones) upon thermal and chemical oxidation, whereas thiophenes do not oxidize. ,, However, we do not observe this trend for the heavy distillate cut and hypothesize that photooxidation versus other forms of oxidation involve different reaction pathways and thus produce different oxidized products. Moreover, the presence of aromatics in the thiophene fractions promotes photooxidation from sunlight because they are known to act as chromophores.…”

Section: Resultscontrasting

confidence: 85%

“…Thiophenic species are the most abundant type of sulfur in petroleum and have been shown to be nonreactive/noncorrosive in refinery operations; they are extremely stable structures, which persist throughout geologic time and survive thermal/catalytic refinery processes. , Conversely, sulfides/disulfides comprise a smaller mass fraction of sulfur-containing species in crude oil, but are much more reactive and corrosive than their thiophenic counterparts. , Moreover, sulfoxides have been detected in crude oils by positive-ion (+) electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS), but were shown to comprise a very small percent of the total sulfur in petroleum . Sulfur content and functionality are especially of interest to refinery/production strategies because governmental regulations limit their concentrations in commercial products to protect the environment and public health, and there are many methods to isolate sulfur species from petroleum. − In line with these concerns, sulfur chemistry is crucial for understanding the formation of water-soluble species through photooxidation of oil spills (fate), as well as environmental consequences (impact). Correspondingly, a study involving photoirradiation of various benzothiophene model compounds along with a high-sulfur crude oil demonstrated that water-soluble sulfur-containing acidic species are produced from photooxidation .…”

Section: Introductionmentioning

confidence: 99%

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Molecular Composition of Photooxidation Products Derived from Sulfur-Containing Compounds Isolated from Petroleum Samples

et al. 2020

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Following the Deepwater Horizon (DWH) oil spill, the limited availability of the Macondo well oil prompted the use of a more widely available surrogate oil supplied by BP, collected from a nearby well. It is chemically similar but has minor compositional differences compared to the oil spilled in DWH. Similarly, the two light sweet crude oils were shown to produce abundant sulfur-containing photoproducts upon solar irradiation, despite a low sulfur content in both parent oils (<0.5 wt %). To investigate the role of chemical functionality in photooxidation of sulfur-containing hydrocarbons, sulfides and thiophenes were isolated from DWH and surrogate parent oils and subjected to laboratory-based irradiation. Their water-and oil-soluble photoproducts were analyzed by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry to access compositional differences between photoproducts of the two oils. The results demonstrate that DWH produces heavily oxidized water-/oil-soluble compounds (up to O 18 S 1 ), whereas the surrogate oil yields species with only up to 14 oxygen atoms (O 14 S 1 ). To understand the behavior of a geochemically different sample, a light distillation cut from an Arabian heavy oil was also subjected to the same preparatory workflow and analysis. The results point to the occurrence of photoinduced polymerization reactions during the production of high-molecular-weight/heavily oxidized water-soluble compounds. Furthermore, thiophene and sulfide fractions from all oils were shown to produce abundant water-and oil-soluble photoproducts upon laboratory-irradiation, confirming the importance of this process in oxidative, surface weathering of oil and in the production of petroleum-derived dissolved organic sulfur species. Sulfides from light oils were susceptible to photooxidation and matched previous reports of low-double bond equivalent O x S 1 species from irradiated DWH and surrogate oils.

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Section: Resultscontrasting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Molecular Composition of Photooxidation Products Derived from Sulfur-Containing Compounds Isolated from Petroleum Samples

et al. 2020

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“…This is consistent with some of previous studies. 20 Even though S 1 class species had higher content than S 2 class species before HDT, the S 2 class species were more active. Figure 4 shows the S 1 class composition of SFEF subfractions and their corresponding HDT products.…”

Section: ■ Results and Discussionmentioning

confidence: 93%

Transformation of Sulfur Compounds in the Hydrotreatment of Supercritical Fluid Extraction Subfractions of Saudi Arabia Atmospheric Residua

et al. 2015

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Atmospheric residue from Saudi Arabia (SZAR) was subjected to supercritical fluid extraction fractionation (SFEF) experiments. Four extractable subfractions (SFEF 1−4) and an unextractable end-cut were obtained. SFEF 1−4 were subjected to a hydrotreating (HDT) test in a mini-tubular reactor packed with commercial hydrodemetallization (HDM) and hydrodesulfurization (HDS) catalysts in order to determine the structural composition transformation of sulfur-containing compounds. Experiments were undertaken at a temperature of 360°C, a hydrogen pressure of 14.7 MPa, a liquid hour space velocity (LHSV) of 0.25 h −1 , and a H 2 /feed ratio of 650:1 (m 3 /m 3 ). The SFEF subfractions and their products were subjected to analysis of their sulfur and nitrogen contents, using an ANTEK 7000S analyzer, and their saturates, aromatics, resins, and asphaltenes (SARA) compositions were analyzed using open column liquid chromatography. The detailed molecular composition of sulfur heteroatom species was determined by methylation, followed by positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). In ESI FT-ICR analysis, the sulfur-containing compounds were characterized in terms of class, type (double bond equivalence, DBE), carbon number distribution, and relative abundance. According to the different number of sulfur atoms, sulfur-containing compounds can be divided into S 1 and S 2 class species. The results show that, depending on different transformation mechanisms, S 1 class species, which have less-aromatic cores, are easy to convert, no matter the side chain length. In addition, S 2 class species with less-aromatic cores and/or less carbon numbers have better hydrogenation reactivities. Meanwhile, S 2 class species with long and/or complex chains would be easy to cleavage into small ones under the reaction conditions. Compare to S 1 class species, S 2 species are more active. The potential transformation of sulfur compounds in HDT of subfractions of atmospheric residua were inferred from the DBE distribution and carbon number data by involving SFEF, methylation followed by FT-ICR MS for sulfur species of SFEF subfractions and their HDT products. The results may help understanding of the heavy oil sulfur removal sequence and catalyst/ process optimization for heavy oil desulfurization and thereby assist the efficient production of clean transporation fuels.

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“…carried out quantitative analysis of sulfides from different crude oils by the approach of oxidation–reduction coupled with chromatography. Nevertheless, it was pointed out that the reaction extents of different sulfides were unequal during the oxidation–reduction process, and some sulfides cannot be reduced as a result of excessive oxidation . Methylation–demethylation is another approach for obtaining high-purity sulfides and showed no discrimination on different sulfides, which enabled more detailed molecular composition analysis of sulfides. − However, the separation process is complex and needs a very long time, which takes at least 1 week to ensure sufficient conversion of the sulfides.…”

Section: Introductionmentioning

confidence: 99%

Isolation of Sulfides from Petroleum for Molecular Characterization by Alumina and Silica Gel Adsorption

Zhang

Chang

et al. 2020

Energy Fuels

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Sulfide (sulfur ether or thioether) is a kind of chemically active compound in petroleum, which has special significance in both geochemistry and oil processing. However, the molecular characterization of sulfides is a challenge because the composition of sulfides is very complex and each individual sulfide generally has a very low concentration. Separation is necessary for an in-depth characterization of these compounds, but it is not easy to achieve thus far. Here, we developed a method for the isolation of sulfides from petroleum fractions. Sulfides have different adsorption behaviors from the petroleum matrix on the aluminum oxide and silica gel. The petroleum fraction was first separated by an alumina column to obtain the mixture of sulfides and nonpolar hydrocarbons, and then the mixture was transferred into the second column, which was packed with silica gel. Hydrocarbons were removed by a nonpolar solvent, and sulfides were eluted from the column with a polar solvent. Isolated fractions were characterized by high-resolution mass spectrometry and gas chromatography (GC). Results show that the method is simple and practical. The purity of the sulfide fraction is acceptable for composition analysis by GC-relevant techniques. The method could be used for routine analysis of sulfides in crude oil and its products.

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Improved methods for the selective isolation of the sulfide and thiophenic classes of compounds from petroleum

Cited by 54 publications

References 4 publications

Molecular Composition of Photooxidation Products Derived from Sulfur-Containing Compounds Isolated from Petroleum Samples

Molecular Composition of Photooxidation Products Derived from Sulfur-Containing Compounds Isolated from Petroleum Samples

Transformation of Sulfur Compounds in the Hydrotreatment of Supercritical Fluid Extraction Subfractions of Saudi Arabia Atmospheric Residua

Isolation of Sulfides from Petroleum for Molecular Characterization by Alumina and Silica Gel Adsorption

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