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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]

Microwave-assisted hydroconversion of demineralized Shengli lignite liquefaction residue (DMSLLR) over Ni-B/SiO2in methanol was investigated under mild conditions. The results show that Ni-B/SiO2significantly catalyzed DMSLLR hydroconversion by increasing the methanol-extractable fraction of hydroconverted DMSLLR to 87.7% over Ni-B/SiO2from 62.3% without catalyst. The yields of alkanes, hydroarenes, alkyl arenes, non-substituted arenes, organooxygen compounds, and organosulfur compounds from catalytic hydroconversion of DMSLLR are drastically higher than those from non-catalytic hydroconversion of DMSLLR. Benzo[ghi]perylene is the most abundant condensed arenes detected. [ABSTRACT FROM PUBLISHER]

Microwave-assisted hydroconversions of demineralized Shengli lignite liquefaction residue (DMSLLR) were investigated over different zeolites in methanol at 140°C. The catalytic effects of the zeolites on the yields and compositions of methanol-soluble portions (MSPs) as well as the structural features of the MSPs and methanol-insoluble portions (MISPs) were examined. The results show that the yields of the MSPs over different zeolites follow the order: HZSM-5 > Hβ > HY > HM; HZSM-5 and Hβ observably promoted DMSLLR hydroconversion to gas chromatography/mass spectrometry-detectable normal alkanes and oxygen-containing organic species, whereas much more arenes were detected in the MSPs from hydrotreated DMSLLR with HY and HM. [ABSTRACT FROM PUBLISHER]

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]

Rice-stalk powder was heated in supercritical methanol at 300°C and the resulting products were analyzed with gas chromatography/mass spectrometer (GC/MS). After the supercritical methanolysis, more than 89% of organic mater in the rice-stalk powder was converted to methanol-soluble species, in which more than 100 organic compounds were detected and most of them are oxygen-containing ones, including ketones, hydroxybenzenes, esters, methoxyaromatics, aldehydes, alkanols, and carboxylic acids. Other species detected are alkanes, alkenes, arenes, and nitrogen- and sulfur-containing organic compounds. [ABSTRACT FROM AUTHOR]