ESCA investigations on Schleenhain lignite lithotypes and the hydrogenation residues

Fiedler, R.; Bendler, D.

doi:10.1016/0016-2361(92)90026-k

Cited by 43 publications

(8 citation statements)

References 8 publications

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“…Figure shows typical XPS spectra of S 2p for the studied coal samples: dem L and Cz, as well as L and Cz oxidized by O 2 /Na 2 CO 3 or PAA which represent highly and moderately oxidized samples. The fitting of S2p peaks (without fixing either positions or half-widths) gave the following binding energies: 163.6 ± 0.1, 165.1 ± 0.2, and 168.0 ± 0.3 eV which correspond respectively to sulfides + thiophenes + thioethers + mercaptans, , sulfoxide C−SO−C, , or sulfones C−SO 2 - C . The first and the third peak are in a very good agreement with literature and the second in a reasonable one; however, it must be added that no constriction on the binding energy was used in the fitting program.…”

Section: Resultssupporting

confidence: 70%

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

2004

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Oxidation of coals of different rank and containing different amounts of sulfur was carried out using O 2 /Na 2 CO 3 . The surface chemical state of some elements (C, O, S) and their content was studied by X-ray photoelectron spectroscopy and compared to those of coal samples oxidized with peroxyacetic acid solution. The extent of surface oxidation depended on the rank of coal, bulk oxygen content of the starting sample, and the type of oxidizing agent. The oxidizing process led to the increase of the amount of oxidized forms of sulfurssulfoxides and sulfones. The changes in the amount of oxygen-containing species were also discussed.

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Section: Resultssupporting

confidence: 70%

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

2004

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“…The corresponding S2p peak was curve resolved using a mixed Lorentzian± Gaussian line shape. Sulfur functionality in coals is assigned from the observed shifting of the binding energy (BE) of the level S2p for different organic sulfur compounds taken as models listed in the literature: 158.7±159.6 eV pyritic, 161.2±162.5 eV sul®dic, 163.7±164.0 eV thiophenes, thioeters and mercaptanes, 166.0 eV sulfoxide, 168.0 eV sulfone, 169.2 eV sulfonate, and 174.8±175.8 eV sulfate [22]. Table 2 shows the quantitative results for sulfur forms obtained by the ASTM method.…”

Section: Methodsmentioning

confidence: 99%

A study of sulfur functionalities in fossil fuels using destructive- (ASTM and Py–GC–MS) and non-destructive- (SEM–EDX, XANES and XPS) techniques

Olivella

Palacios

Vairavamurthy

et al. 2002

Fuel

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A set of Spanish coals and oil shales were studied using destructive and non-destructive techniques to identify the functionalities of the sulfur compounds. The selected samples included organic-sulfur-rich Spanish lignites mined in the Mequinenza, Utrillas and Calaf basins; calcareous source-rocks from Organya Á and sulfur-rich oil shales from Ribesalbes. Using analytical pyrolysis coupled to gas chromatography±mass spectrometry, we estimated the ratio S org /C in these coals and oil shales, and compared them with those obtained by the ASTM method D2492. Also, a scanning electron microscope (SEM) coupled to an energy-dispersive X-ray spectrometer (EDX) allowed the direct determination of organic sulfur content in coals. Two major non-destructive techniques, XANES and XPS, were used to investigate sulfur functionalities, such as pyritic, sul®dic, thiophenic, sulfoxide, sulfone, sulfonate and sulfate forms. The study shows that sulfur characterization in coal is not without dif®culties and no method is exempt from problems and the introduction of possible artifacts. q

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“…It could be observed that the great contribution mainly resulted from various organic oxygen sources of C−O groups at the BE value ∼532.9 eV, CO groups at the BE value ∼531.4 eV, and OC−O groups at the BE value ∼535.4 eV in LZ coal. 68,69 Meanwhile, inorganic oxygen sources from different minerals in LZ coal should be noted, mainly including some oxides, quartz (SiO 2 ), and kaolinite (Al 2 Si 2 O 5 (OH) 4 ) as shown in Figure 5a. Especially for the latter two silicon-based minerals, they owned the propensity to enrich on the upper surface of coal particles 22 and overlapped with some organic oxygen functional groups (e.g., CO groups, C−O groups) in a certain XPS regions, 70 which complicated identification and quantification of the related organic oxygen functional groups.…”

Section: Energy and Fuelsmentioning

confidence: 99%

In-Depth Investigation of Chemical Looping Combustion of a Chinese Bituminous Coal with CuFe₂O₄ Combined Oxygen Carrier

Wang

et al. 2016

Energy Fuels

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Coal is of heterogeneous nature with a complex chemical structure, which is closely associated with its reactivity. In this research, from the perspective of the chemical structure of coal, reaction characteristics of the as-synthesized CuFe 2 O 4 oxygen carrier (OC) with a typical Chinese bituminous coal (designated as LZ) were deeply investigated using thermogravimetric analysis (TGA). Also, the effect of CuFe 2 O 4 oxygen excess number Φ on the reaction behavior of LZ coal with CuFe 2 O 4 was highlighted. TGA investigation of LZ coal reaction with CuFe 2 O 4 at Φ = 1.0 displayed the enhanced reactivity of CuFe 2 O 4 , which was useful to conversion of the aromatic matrix in LZ coal. Furthermore, during LZ coal reaction with CuFe 2 O 4 in the TGA, the gaseous products evolved from the condensed flue gas were in situ analyzed using Fourier transform infrared (FTIR), which indicated that most of the CO 2 resulted from oxidation of CO by CuFe 2 O 4 OC. Meanwhile, the solid product left after LZ coal reaction with CuFe 2 O 4 was analyzed with X-ray photoelectron spectroscopy (XPS), which revealed that oxidation and conversion of the C−C/C−H groups was the limited step at the molecular scale for full conversion of coal. Finally, the effect of CuFe 2 O 4 excess number Φ for LZ coal reaction with CuFe 2 O 4 was investigated by TGA, and the solid product left was analyzed by XPS, which indicated that C−C/C−H was more effectively converted at CuFe 2 O 4 Φ = 1.0 than Φ = 0.5 and 1.5 at the final reaction temperature of 900 °C. In addition, the mechanism of coal oxidation by CuFe 2 O 4 was also explored, and the C−C/C−H involved in LZ coal was preferentially oxidized to form C−O groups and then further converted to OC−O groups through the formed intermediate CO groups. Overall, this research was much beneficial for a mechanistic understanding of the conversion of coal in a CLC system and promotion of the efficient utilization of coal.

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ESCA investigations on Schleenhain lignite lithotypes and the hydrogenation residues

Cited by 43 publications

References 8 publications

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

A study of sulfur functionalities in fossil fuels using destructive- (ASTM and Py–GC–MS) and non-destructive- (SEM–EDX, XANES and XPS) techniques

In-Depth Investigation of Chemical Looping Combustion of a Chinese Bituminous Coal with CuFe₂O₄ Combined Oxygen Carrier

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ESCA investigations on Schleenhain lignite lithotypes and the hydrogenation residues

Cited by 43 publications

References 8 publications

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O2/Na2CO3 or Peroxyacetic Acid Solution. XPS Studies

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O2/Na2CO3 or Peroxyacetic Acid Solution. XPS Studies

A study of sulfur functionalities in fossil fuels using destructive- (ASTM and Py–GC–MS) and non-destructive- (SEM–EDX, XANES and XPS) techniques

In-Depth Investigation of Chemical Looping Combustion of a Chinese Bituminous Coal with CuFe2O4 Combined Oxygen Carrier

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Product

Resources

About

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

The Comparison of Oxygen and Sulfur Species Formed by Coal Oxidation with O₂/Na₂CO₃ or Peroxyacetic Acid Solution. XPS Studies

In-Depth Investigation of Chemical Looping Combustion of a Chinese Bituminous Coal with CuFe₂O₄ Combined Oxygen Carrier