Development of Researches on Coal Chemical Structure. Recent Trends and Future Outlook Since Krevelen's Researches.

Sakawa, Mitsuhiro

doi:10.3775/jie.70.8_782

Cited by 6 publications

(5 citation statements)

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“…It is known that more than 60% of the C atoms in coal exist in aromatic forms, , mainly consisting of 1−4 fused aromatic rings; thus, coal reactivity is strongly dependent on the aromatic structure . Because the large bonding energy of aromatic rings is lessened by reducing the CC bonds to C−C bonds, the cracking reactivity of the polycylic aromatic system can be greatly enhanced by hydrogenation of the aromatic rings .…”

Section: Introductionmentioning

confidence: 99%

Activated Carbon-Catalyzed Hydrogenation of Polycyclic Arenes

et al. 2004

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Benzene and four polycyclic arenes (PAs) were used as substrates and their hydrogenation reactions were conducted over activated carbon (AC) at 300 °C to examine the relationship between their molecular structures and reactivities. The results show that the AC catalyzed the hydrogenation of the PAs selectively and that the reactivities of the arenes toward hydrogenation were dependent on the hydrogen-accepting abilities of the arenes and on the adsorption strengths of the arenes on the catalyst surface. The related mechanisms for hydrogen transfer were also discussed.

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Section: Introductionmentioning

confidence: 99%

Activated Carbon-Catalyzed Hydrogenation of Polycyclic Arenes

et al. 2004

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“…When the coal, which had been oxidized and then swollen by treatment with tetralin, was pyrolyzed, the tar yield was higher than that of the raw coal. Since more than 60 mol % of the carbon atoms in coal are aromatic, − the pyrolysis reactivity of coal is strongly dependent on the aromatic structure. In our earlier studies, we reported on the oxidation of Yallourn coal with aqueous H 2 O 2 in the presence of 1-propanol.…”

Section: Introductionmentioning

confidence: 99%

Relationship between Pyrolysis Reactivity and Aromatic Structure of Coal

et al. 2000

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Illinois No. 6 coal was depolymerized by treatment with trifluoromethanesulfonic acid in methylcyclopentane at 120 °C. The yield of tetrahydrofuran (THF) extract was increased to 89 wt %. This increase was explained by the cleavage of bridges between aromatic units. The extract (TS d fraction) was further hydrogenated using a Ru/carbon catalyst in a mixed solvent of THF and acetic acid at 120 °C for 12-72 h under a hydrogen pressure of 10 MPa. Phenolic resin and polystyrene samples were used as references and were also hydrogenated over Ru/Al 2 O 3 catalyst under the same conditions. After hydrogenation for 72 h, the aromaticity of the hydrogenated TS d fraction (H-TS d fraction), f a , decreased to 0.33 from the original value, 0.6. The pyrolysis reactivity of the treated coals was evaluated using a Curie-point pyrolyzer (CPP) at 500-764 °C in a stream of helium. The reactivity of the TS d fraction was greatly enhanced as a result of the hydrogenation, and 96 wt % of the H-TS d fraction was converted to volatiles during the pyrolysis at 764 °C. A good correlation between the aromaticity and the yield of volatiles was found for both the treated coals and phenolic resins, but not for the polystyrenes. This suggests that pyrolysis reactivity was related to the aromatic structures of the main chains, and that those structures were changed by the hydrogenation.

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“…Today the conception of two-component molecular structure, known as "guest-host" [37,41], net structure [29,42,43], percolation lattice [44,45], or two-phase model [26,46,47] is widely used. This conception originates from the studying of swelling and dilution of coal microcomponents in pyridine [48] and polar or nonpolar solvents [49].…”

Section: Hypothetic Models Of Coal Structurementioning

confidence: 99%

Composition and Structure of Coal Organic Mass. Analytical Review

Barsky¹,

Gulyaev²,

Rudnitsky³

2009

ChChT

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The research works dedicated to the formation regularities of solid fuels chemical structure were analyzed. Modern conceptions of coals chemical structure, which are becoming deeper owing to tooling growth and facts accumulation, were examined by means of critical comparison of different hypothetical models of solid fuels “molecular” structure. The most general points of the respective theories were formulated, according to which “soft” influence on coal structure primary elements bonds system allows bringing its chemical potential to the maximum.

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Development of Researches on Coal Chemical Structure. Recent Trends and Future Outlook Since Krevelen's Researches.

Cited by 6 publications

References 0 publications

Activated Carbon-Catalyzed Hydrogenation of Polycyclic Arenes

Activated Carbon-Catalyzed Hydrogenation of Polycyclic Arenes

Relationship between Pyrolysis Reactivity and Aromatic Structure of Coal

Composition and Structure of Coal Organic Mass. Analytical Review

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