Solubilization of lignite with superacid (trifluoromethanesulfonic acid)/isopentane at the mild conditions

Shimizu, Ken D.; Karamatsu, H.; Iwami, Yoshihiro; Inaba, Atsushi; Suganuma, Akira; Saito, Ikuo

doi:10.1016/0378-3820(94)00030-w

Cited by 14 publications

(5 citation statements)

References 11 publications

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“…Acid catalyzed coal depolymerization has been used as an analytical technique and for liquefaction. 269,270 Liquid acids such as BF 3 in the presence of excess phenol, 271 p-toluenesulfonic acid, 272 HF-BF 3 , 269 HF-TaF 5 273 and CF 3 SO 3 H/I 2 274,275 and molten salt, 276,277 have been widely studied at temperatures ranging from 100 C to 350 C with low hydrogen pressure. The efficiency of a homogeneous catalyst over heterogeneous catalyst is expected to be high because a heterogeneous inorganic solid cannot penetrate the macromolecular network structure of insoluble coal.…”

Section: Acid Catalystsmentioning

confidence: 99%

Clean liquid fuels from direct coal liquefaction: chemistry, catalysis, technological status and challenges

Vasireddy

Morreale

Cugini

et al. 2011

Energy Environ. Sci.

345

209

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Increased demand for liquid transportation fuels coupled with gradual depletion of oil reserves and volatile petroleum prices have recently renewed interest in coal-to-liquids (CTL) technologies. Large recoverable global coal reserves can provide liquid fuels and significantly reduce dependence on oil imports. Direct coal liquefaction (DCL) converts solid coal (H/C ratio z 0.8) to liquid fuels (H/C ratio z 2) by adding hydrogen at high temperature and pressures in the presence or absence of catalyst. This review provides a comprehensive literature survey of the coal structure, chemistry and catalysis involved in direct liquefaction of coal. This report also touches briefly on the historical development and current status of DCL technologies. Key issues, challenges involved in DCL process and directions for the future research are also addressed.

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Section: Acid Catalystsmentioning

confidence: 99%

Clean liquid fuels from direct coal liquefaction: chemistry, catalysis, technological status and challenges

Vasireddy

Morreale

Cugini

et al. 2011

Energy Environ. Sci.

345

209

View full text Add to dashboard Cite

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“…Although liquid or soluble acids such as ZnCl 2 , SnCl 2 , HF–BF 3 , , and CF 3 SO 3 H proved to be effective for coal liquefaction, they are corrosive and cannot be effectively recovered, which limits their utilization in commercial process. Since solid acids have the advantages of low corrosion and good retrievability, increasing attention is paid to develop solid acids for coal liquefaction.…”

Section: Catalytic Hydroconversion Of Lignites Under Mild Conditionsmentioning

confidence: 99%

Advances in Lignite Extraction and Conversion under Mild Conditions

Wei

Yan

et al. 2015

Energy Fuels

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Lignites are abundant coal resources, but they are low-quality fuel for direct combustion because of their high water content, high ash yield, and low calorific value. Upgrading technologies for lignites such as drying and pyrolysis have been widely investigated. Lignite conversion under mild conditions for producing ash-free coals, value-added chemicals, and/or liquid fuels also deserves attention. This paper reviews recent developments in extraction and mild conversion of lignites. The related techniques, including sequential extraction, thermal dissolution, mild oxidation, and catalytic hydroconversion of lignites, are summarized in detail. In addition, the application of high resolution mass spectrometry in determining lignite-derived products is presented. Future investigations on efficient utilization of lignites are also suggested.

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“…[134][135][136] Relatively low conversions with diphenyl ether and biphenyl as model compounds indicated that aromatic ether and aryl-aryl linkages are more difficult to cleave under these conditions. Triflic acid was effective to convert lignite and Taiheiyo coal to pyridine-solubles almost completely in the presence of isopentane without hydrogen (150 C, 3 h).…”

Section: Conversion Of Saturated Hydrocarbonsmentioning

confidence: 99%