Structural Evaluation of Zao Zhuang Coal

Nomura, Masakatsu; Artok, Levent; Murata, Satoru; Yamamoto, Akira; Hama, Hiroshi; Gao, Hong; Kidena, Koh

doi:10.1021/ef9701448

Cited by 44 publications

(43 citation statements)

References 38 publications

(67 reference statements)

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“…Sulfur was not considered in the hypothetical average model structures because of its negligible content. 41 The hypothetical molecular formulas for selected CT-asp at 0 and 60 min were shown in Figure 8 and were in good agreement with the experimental average molecular formulas.…”

Section: Resultssupporting

confidence: 70%

Reactivity and Structure Changes of Coal Tar Asphaltene during Slurry-Phase Hydrocracking

Deng

et al. 2017

Energy Fuels

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Coal tar asphaltene (CT-asp) is one of the important heavy components of coal tar. It has significant influences on the conversion efficiency of slurry-phase hydrocracking. The reactivity and structure changes of CT-asp in a slurry-phase process were investigated. Experimental results showed that the conversion of CT-asp reached 66.5 wt % with a significant decrease of sulfur and oxygen contents as the reaction time increased. The CT-asp obtained from the hydrocracking reaction carried out for different time has been analyzed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and 1 H/ 13 C nuclear magnetic resonance. The chemical structural analysis results confirmed that CT-asp was mainly composed of more aromatic rings with oxygen functional groups and possessed a higher aromaticity and shorter aliphatic chains after hydrocracking. Moreover, the effective cracking of carbonyl groups, pyrrolic nitrogen, and alkyl sulfides in CT-asp was found during the slurry-phase hydrocracking. It was considered that a structure with an average of two aromatic rings per aromatic sheet existed in the average molecule of CT-asp, and the aromatic sheets were condensed with each other through diphenyl-like structures or oxo-bridged linkages. In addition, a free radical reaction pathway of CT-asp in slurry-phase hydrocracking was proposed on the basis of the main detected products and the molecular structural changes.

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Section: Resultssupporting

confidence: 70%

Reactivity and Structure Changes of Coal Tar Asphaltene during Slurry-Phase Hydrocracking

Deng

et al. 2017

Energy Fuels

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“…However, malonic acid was not detected in either MEOP or MEAP because it is labile toward RICO. 54 Various BPCAs are mainly generated from the oxidation of different aromatic rings in coals. The macromolecular precursors of the BPCAs can be classified into catacondensed aromatics (CCAs), polyaryls, and PCAs.…”

Section: Methodsmentioning

confidence: 99%

Structural Characterization of Typical Organic Species in Jincheng No. 15 Anthracite

et al. 2015

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The structures of typical organic species in Jincheng No. 15 anthracite (J15A) were characterized by solid-state 13 C nuclear magnetic resonance, X-ray photoelectron spectrometry, X-ray diffraction, and Fourier transform infrared spectrometry in combination with gas chromatography/mass spectrometry and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry analyses of the resulting soluble organic species from ruthenium-ion-catalyzed oxidation (RICO) of J15A. The results show that the typical organic species in J15A are condensed aromatics, along with small amounts of methyl group as the dominant side chain on the condensed aromatic rings (CARs) and methylene linkage connecting the CARs. Every aromatic cluster contains five rings on average, and the substituted degree of each aromatic ring is very low. In addition, J15A is rich in peri-condensed aromatics but poor in cata-condensed aromatics and polyaryls. The oxygen functional groups in J15A include C−O and >CO groups. Pyrrolic nitrogen species and arylthiophenes are the main organic nitrogen and sulfur species in J15A, respectively.

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“…In addition, many structural models of coals based on the analyses of structural characters were constructed. − In 1942, Fuchs et al proposed the first coal structural model based on the pyrolysis products. In 1984, the classic Shinn model was proposed based on the products of liquefaction combined with the results of elemental analysis, aromaticity analysis, and the analysis of chemical functional groups .…”

Section: Introductionmentioning

confidence: 99%

Structures of Aromatic Clusters of Different Coals Based on Benzene Carboxylic Acids from Coal via Oxidation

Yang

Hou

et al. 2017

Energy Fuels

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Benzene carboxylic acids (BCAs) are considered to be an important group of chemicals and widely used in the chemical industry. The generation of BCAs from coal via oxidation is widely studied, indicating that the distributions of BCAs are various with different coals and the yields of BCAs with lower numbers of carboxyl groups increase in the process of coalification. However, the relationship between distributions of BCAs and the aromatic clusters of coal is unclear. In this work, combined with the results of distributions of BCAs and 13 C NMR, the most probable aromatic clusters in different coals were proposed. The result indicates that, in the process of coalification (from lignite to anthracite), the aromatic cluster size and the degree of condensed aromatic rings both increase with an increase in carbon content or coal rank, but the substituted degree of aromatic rings decreases. When the carbon content of coal is lower than 87%, the aromatic rings in coal are arranged in a linear catenation manner. When the carbon content of coal is more than 87%, aromatic rings in coal are arranged in a circular catenation manner. The substituents of aromatic clusters are distributed uniformly on the aromatic rings. With the increase of coal rank, the average substituted carbon chain length (L n ) decreases; namely, more and more aromatic clusters tend to be directly connected to others. These structural features make the yields of benzene dicarboxylic acids and benzene tricarboxylic acids (BTAs) increase with coal ranks from lignite to anthracite via oxidation. The highest yield of BCAs is benzene tetracarboxylic acids from Xiaolongtan lignite to Xuanzhong bituminous coal via oxidation. With further increasing coal rank, the highest yield of BCAs is BTAs from Pingdingshan bituminous coal to Taixi anthracite via oxidation. The proposed aromatic clusters well explain the reasons that the yields of BCAs with lower numbers of carboxyl group are significantly increased with increasing coal rank.

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Structural Evaluation of Zao Zhuang Coal

Cited by 44 publications

References 38 publications

Reactivity and Structure Changes of Coal Tar Asphaltene during Slurry-Phase Hydrocracking

Reactivity and Structure Changes of Coal Tar Asphaltene during Slurry-Phase Hydrocracking

Structural Characterization of Typical Organic Species in Jincheng No. 15 Anthracite

Structures of Aromatic Clusters of Different Coals Based on Benzene Carboxylic Acids from Coal via Oxidation

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