Sulfur speciation in heavy petroleums: Information from X-ray absorption near-edge structure

Waldo, Geoffrey S.; Carlson, Robert M. K.; Moldowan, J. Michael; Peters, Kenneth E.; Penner‐Hahn, James E.

doi:10.1016/0016-7037(91)90343-4

Cited by 215 publications

(130 citation statements)

References 56 publications

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“…Differential reduction of organic S compounds to H 2 S does not identify the organic functional groups or the intermediate oxidation states of S. The pyrolysis -gas chromatography -mass spectrometry approach is used for coal, kerogens and aquatic humic substances, but is limited to speciation of thermally stable forms of S. Within this context, S K-and L-edge XANES spectroscopy are proving to be invaluable, non-destructive, and in some cases in situ, techniques for characterizing the S functional groups in natural organic matter. The method has been applied to coals (e.g., Hussain et al 1982, Spiro et al 1984, Huffman et al 1991, George et al 1991, Brown et al 1992, Kasrai et al 1990, 1996b, Olivella et al 2002, Huggins et al 1997, heavy petroleum asphalts (bitumens) and asphaltenes (George & Gorbaty 1989, Gorbaty et al 1991, Waldo et al 1991, Kasrai et al 1994, Vairavamurthy et al 1994, Sarret et al 1999, kerogens , Sarret et al 2002 and sediments, soils and humus (Vairavamurthy et al 1994, 1997, Morra et al 1997, Olivella et al 2002, Qian et al 2002, Beauchemin et al 2002, Solomon et al 2003, Jokic et al 2003. FIG.…”

Section: Organic Geochemistrymentioning

confidence: 99%

Xanes Spectroscopy of Sulfur in Earth Materials

Fleet¹

2005

The Canadian Mineralogist

148

134

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X-ray absorption near-edge structure (XANES) spectroscopy is the ideal non-destructive technique for characterizing and quantifying S species in compositionally complex natural materials such as silicate glasses and minerals, coals, asphalts and asphaltenes, kerogens and humic substances. Sulfur absorption edges represent the transition of S 1s and 2p core electrons to unoccupied antibonding orbitals at the bottom of the conduction band. Shifts in the position of the absorption-edge feature of S K-and L-edge XANES spectra constitute a chemical ruler for oxidation state of both inorganic and organic species of S; the S K edge shifts from 2469.5 eV for chalcopyrite (2-oxidation state) to 2482 eV for gypsum (6+). However, chemical state of S in Earth materials is most readily assigned by comparing the overall XANES profi le with spectra for reference compounds. Sulfur XANES spectra are reviewed for pyrite, troilite, pyrrhotite and NiAs-type Co 0.923 S and Ni 0.923 S, niningerite (MgS), oldhamite (CaS), alabandite (MnS) and cubic FeS, and sphalerite and related phases, as well as for selected solid-solutions of the monosulfi des. Sulfur XANES spectra for FeS, CoS, NiS, MgS, CaS, MnS and ZnS have been simulated by multiple scattering calculations. The S K-edge XANES of transition-metal-bearing monosulfi des generally show anomalous absorption consistent with hybridization of the fi nal S 3p * antibonding states with empty 3d orbitals on the metal atoms. Various applications of S K-and L-edge XANES fi ngerprinting are discussed, including speciation of inorganic S in basaltic glasses, lazurite and haüyne, identifi cation of organic functional groups of S in coals, kerogens and humic substances extracted from subtropical soils and marine sediments, and the association of sulfated sugars with calcifi cation of coral aragonite skeletons.Keywords: XANES spectroscopy, chemical state of S, electronic structure and bonding, sulfi des, sulfates, magma, organic geochemistry. SOMMAIRELa spectroscopie d'absorption des rayons X dans la région pré-seuil (XANES) s'avère la technique non-destructive par excellence pour caractériser et quantifi er les espèces de soufre dans les matériaux naturels de composition complexe, par exemple les verres silicatés et minéraux, charbons, asphaltes et asphaltènes, kérogènes et substances humiques. Les seuils d'absorption du soufre résultent de la transition des électrons 1s et 2p du noyau à des orbites non occupés anti-liaisons à la base de la bande de conduction. Les décalages dans la position des seuils K et L du soufre des spectres XANES constituent un barème chimique important dans l'évaluation du niveau d'oxydation du soufre, à la fois pour les espèces inorganiques et organiques; le seuil K est déplacé de 2469.5 eV dans la chalcopyrite (valence 2-) à 2482 eV dans le gypse (6+). Toutefois, l'état du soufre des matériaux terrestres est plus facilement attribué en comparant le profi l XANES entier d'un échantillon aux spectres des composés de réfé-rence. Les spectres XANES du soufre so...

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Section: Organic Geochemistrymentioning

confidence: 99%

Xanes Spectroscopy of Sulfur in Earth Materials

Fleet¹

2005

The Canadian Mineralogist

148

134

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“…For the Gela sample stored over a long period the majority of the pyrite is converted to sulphate. It is expected that decomposition of organic sulphides account for a large proportion of the evolved H2S at moderate temperatures (Waldo et al, 1991). Although thiophenic forms do indeed appear more stable, sulphur content in both organic sulphide and thiophenic forms decrease during pyrolysis at 260/275°C.…”

Section: Discussionmentioning

confidence: 99%

“…To aid quantification it is therefore desirable to simplify the fitting procedure. Waldo et al (1991) established that the white line intensities of a series of sulphur containing compounds were closely correlated in a linear manner to the edge energy. Here we have used the relationship between white line intensity and energy to construct a simple model of the sulphur absorption spectrum.…”

Section: Introductionmentioning

confidence: 98%

Evolution of sulfur during pyrolysis of petroleum kerogens

Lynch¹,

Everlien²,

Leblond³

et al. 1999

J Synchrotron Radiat

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Sulphur K edge spectroscopy was used to differentiate types of sulphur present in petroleum asphaltenes and kerogens. A simplified model of the near edge structure enabled quantification of the different sulphur forms. The evolution of the sulphur edge following pyrolysis of kerogens confirms that thiophenic sulphur is more stable than organic sulphide forms. Pyrite retained in the kerogens may partially transform to iron sulphate during air storage. During pyrolysis FeS2 is regenerated and subsequently converted to FeS, contributing to the release of H2S. The results show that exchange between organic and mineral forms of sulphur is limited.

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“…[7] XANES (X-ray absorption near-edge structure) spectroscopy is a powerful technique when analyzing sulfur chemistry in solids. It has been used to investigate organic and inorganic sulfur bonding in coals, [8,9] varying heavy petroleums, [10] materials for electrodes in batteries, [11] as well as in different earth materials and sediments. [12][13][14] In a selection of industrial anode cokes and baked anodes, XANES revealed the sulfur speciation to be organic sulfur rings, primarily as thiophene-containing polycyclic aromatic hydrocarbons.…”

Section: Introductionmentioning

confidence: 99%

A XANES Study of Sulfur Speciation and Reactivity in Cokes for Anodes Used in Aluminum Production

Jahrsengene

Wells

Rørvik

et al. 2018

Metall Mater Trans B

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Availability of anode raw materials in the growing aluminum industry results in a wider range of petroleum cokes being used to produce carbon anodes. The boundary between anode grade cokes and what previously was considered non-anode grades are no longer as distinct as before, leading to introduction of cokes with higher sulfur and higher trace metal impurity content in anode manufacturing. In this work, the chemical nature of sulfur in five industrial cokes, ranging from 1.42 to 5.54 wt pct S, was investigated with K-edge XANES, while the reactivity of the cokes towards CO2 was measured by a standard mass loss test. XANES identified most of the sulfur as organic sulfur compounds. In addition, a significant amount is identified (16 to 53 pct) as S-S bound sulfur. A strong inverse correlation is observed between CO2-reactivity and S-S bound sulfur in the cokes, indicating that the reduction in reactivity is more dependent on the amount of this type of sulfur compound rather than the total amount of sulfur or the amount of organic sulfur.

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Sulfur speciation in heavy petroleums: Information from X-ray absorption near-edge structure

Cited by 215 publications

References 56 publications

Xanes Spectroscopy of Sulfur in Earth Materials

Xanes Spectroscopy of Sulfur in Earth Materials

Evolution of sulfur during pyrolysis of petroleum kerogens

A XANES Study of Sulfur Speciation and Reactivity in Cokes for Anodes Used in Aluminum Production

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