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Corn stalk was liquefied in methanol under sub/supercritical states and the reaction mixture was extracted with methanol, acetone, and acetone/CS2 (1:1 vol/vol) mixed solvent sequentially. The effects of temperature, time, and the ratio of corn stalk to solvent on the yields of extracts and residue were investigated. The extracts were analyzed with a gas chromatography/mass spectrometer. The results show that corn stalk can be liquefied in sub- and supercritical methanol and over 98% of corn stalk is converted at 300°C and 1.5 h. Benzene-ring-containing compounds, and methyl alkanoates are the dominant constituents of the methanol-extractable fractions from corn stalk liquefied with methanol. [ABSTRACT FROM AUTHOR]

Geting bituminous coal was sequentially extracted with petroleum ether, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature, affording extracts 1 to 5 (E1to E5). In total, 77 organooxygen compounds (OOCs) were identified from E3by gas chromatography/mass spectrometry analysis. The OOCs include 4 alkanols, 8 arenols, 5 ethers, 5 aldehydes, 14 non-nitrogen ketones, 19 nitrogen-containing ketones, 11 alkanoic acids, and 11 esters. This investigation provides an effective approach to the enrichment of OOCs in coals, favoring understanding of the diversity of the organooxygen compounds. [ABSTRACT FROM AUTHOR]

Pocahontas No. 3 coal was extracted with CS2, n-hexane, benzene, methanol, acetone, and acetone/CS2 (1:1 vol/vol) mixed solvent sequentially. The resulting six extracts were analyzed with gas chromatography/mass spectrometer (GC/MS). Hexathiane, octathiocane, 23 sulfur-containing organic species, and 21 nitrogen-containing organic species were detected in the extracts. Sulfur-containing organic species detected in the extracts include dialkyl- and disulfides, dimexano, dibenzothiophene, benzonaphthothiophene, and their methyl-derivatives, among which dimexano and dixanthogen were seldom reported in any sediments. Methanol is effective for extracting sulfur-containing organic species without aromatic ring. Most of the nitrogen-containing organic species detected in the extracts are acridinone, carbazole and their methyl-derivatives, benzocarbazoles, amines, phenanthridinone, and piperidinone. The species number of nitrogen-containing organic compounds detected in the extracts increased with the increase in solvent polarity. Different from those reported previously, N and O atoms often coexist in the same compounds in the present study. [ABSTRACT FROM AUTHOR]