Segregation patterns and characteristics differences of superfine pulverized coal ground by three pulverizing systems

Ma, Yang; Liu, Jiaxun; Jiang, Yabin; Jiang, Xiumin; Ma, Junfang; Jiao, Anyao

doi:10.1016/j.apt.2018.12.002

Cited by 9 publications

(3 citation statements)

References 53 publications

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“…This is also the reason that no LCNAs with carbon numbers <10 are observed in all the samples. In addition, the HN_8.1 coal endures the longest crushing time among the eight samples, and thus, the temperature in the milling system is higher, 29 promoting the volatilization of LCNAs. Moreover, the appearance of reverse comminution that reduces the specific surface area of HN_8.1 might also be a reason.…”

Section: Resultsmentioning

confidence: 99%

Solvent Extraction of Superfine Pulverized Coal. Part 1. Composition of the Extract

et al. 2020

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The chemical properties of coal extracts play a crucial role in understanding coal structure, constructing coal model, and developing clean coal technology. However, there is little knowledge about the superfine comminution-induced mechanochemical effect on the coal extraction process and composition of the extracts. In this paper, typical solid-phase microextraction (SPME) and solvent extraction experiments were performed, which can identify both nonpolar and polar molecules in the coal structure, providing reliable structural information. Then, three different analytical methods were employed to characterize the chemical properties of the extracts, including gas chromatograph-time-of-flight-mass spectrometry (GC-TOF-MS), GC-triple quadrupole-MS (GC-QqQ-MS), and GC−MS. The final results show that the particle size has a notable impact on the composition of nonpolar molecules based on SPME. Polycyclic aromatic hydrocarbons (PAHs) were detected through GC-QqQ-MS in order to study the relation between the AMHs and coal structure. More stabilized structures of the "angular" PAHs were observed in higher ranked coals. In addition, the detailed hydrocarbons, oxygen-containing, and heteroatom-containing species were identified based on GC−MS results. The content of hydrocarbons monotonically increases with the decrease of the particle size, while the constituents with carbonyl groups such as ketone and ester also increase, shedding light on the construction of a multicomponent coal model with structural diversity. The findings from this work give a more comprehensive understanding about the particle size effect on coal extraction and provide a new perspective to understand the chemical morphology of superfine pulverized coal.

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Section: Resultsmentioning

confidence: 99%

Solvent Extraction of Superfine Pulverized Coal. Part 1. Composition of the Extract

et al. 2020

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“…Moreover, as the particle sizes decrease, the inertinite content decreases and the vitrinite content increases. 51 The higher content of pyrite in inertinite and larger amount of thiophene in vitrinite 20 may also affect the content of organic and inorganic sulfur in coal.…”

Section: Resultsmentioning

confidence: 99%

“…The increase of ash enriched with minerals results in the increase of inorganic sulfur like pyrite in small coal fractions. Moreover, as the particle sizes decrease, the inertinite content decreases and the vitrinite content increases . The higher content of pyrite in inertinite and larger amount of thiophene in vitrinite may also affect the content of organic and inorganic sulfur in coal.…”

Section: Results and Discussionmentioning

confidence: 99%

Chemical Properties of Superfine Pulverized Coal Particles. Part 4. Sulfur Speciation by X-ray Absorption Near-Edge Structure Spectroscopy

et al. 2020

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Exploring the transformation mechanisms of sulfur during the superfine comminution plays a crucial role in constructing a coal macromolecular model and developing clean coal technologies. In this work, the occurrences of sulfur in raw coal were quantitatively analyzed by X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS). The sulfur forms in two typical rank coals were compared, and the influence of particle size on the transformation of sulfur was elucidated. Furthermore, the mechanochemical effect on sulfur speciation during the superfine comminution was focused on. The final results indicate that HN coal contains more thiophene with ring structures, while sulfate is the dominant sulfur form in NMG coal. In addition, pyrite can be easily oxidized to sulfate and elemental S, while sulfide, sulfoxide, and sulfone are susceptible to transformation to thiophene during the coalification. It is worth noticing that during the superfine comminution, the organic sulfur shows a decreasing trend, while the inorganic sulfur shows the opposite, suggesting that a conversion from organic to inorganic sulfur exists due to the mechanochemical effect. In addition, two conversion pathways of sulfur are concluded, i.e., sulfide → sulfoxide → sulfone and thiophene → sulfoxide → sulfone → sulfate, which further elucidate the sulfur transformation mechanisms in coal. As the particle size decreases, there is an evident decline for sulfide and thiophene, while pyrite, elemental S, and sulfate generally increase. As for sulfoxide and sulfone, different tendencies are observed in HN and NMG coals due to the complex oxidation processes. The combined application of XANES and XPS is recommended for better characterization of the sulfur speciation and distribution due to the different probing depths in coal particles. This research provides a comprehensive understanding of the mutual transformation between organic and inorganic sulfur in coal. The elucidation of sulfur migration pathways can further promote the exploitation of more valuable desulfurization methods.

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Microscopic pyrolysis mechanisms of superfine pulverized coal based on TG-FTIR-MS and ReaxFF MD study

Liu,

Yang,

Liu

et al. 2024

Energy

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Segregation patterns and characteristics differences of superfine pulverized coal ground by three pulverizing systems

Cited by 9 publications

References 53 publications

Solvent Extraction of Superfine Pulverized Coal. Part 1. Composition of the Extract

Solvent Extraction of Superfine Pulverized Coal. Part 1. Composition of the Extract

Chemical Properties of Superfine Pulverized Coal Particles. Part 4. Sulfur Speciation by X-ray Absorption Near-Edge Structure Spectroscopy

Microscopic pyrolysis mechanisms of superfine pulverized coal based on TG-FTIR-MS and ReaxFF MD study

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