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Wheat stalk was pyrolyzed under microwave irradiation and different dilute acids pretreatment, and the pyrolytic mixture were extracted with tetrahydrofuran. The effects of dilute acids pretreatment on the yield of tetrahydrofuran-extractable fraction and the selective conversion of wheat stalk under microwave irradiation were investigated. Compositions of extractable fraction were analyzed with gas chromatography/mass spectrometry. The results indicated that acids can remarkably improve the formation of furfural, pyran-2-one, and 2-butenal, etc. [ABSTRACT FROM PUBLISHER]

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]

Diversity of urban energy system structure (UESS) was analyzed based on information entropy. To find out the evolution law of UESS and thus provide principles to coordinate and optimize the UESS, the correlative relationship model between UESS and its influencing factors can be developed using the partial least square (PLS) regression. Here we took Xiamen City as an example to analyze the evolution tendency and the influencing factors of diversity of energy supply structure (ESS) and energy demand structure (EDS). The results showed that, on the whole, the diversity of ESS in Xiamen was rising over time as a logistic curve from 1996 to 2003, with reducing speed from 1999 though. While in the period, EDS in Xiamen City didn't improve efficiently. Urbanization level, population, gross domestic product (GDP), and the third industrial structure had significantly affected ESS. Meanwhile, number of vehicles, GDP, population, per capita disposable income, and energy eco-efficiency had obvious influences on EDS. As for Xiamen City, the improvement of diversity of EDS should be especially emphasized. [ABSTRACT FROM AUTHOR]

A three-dimensional finite element model is established to study factors influencing factures in oriented hydraulic fracturing. The results indicate factors include horizontal principal stress difference and the angle between oriented perforation and the maximum horizontal stress. The computations reveal that hydraulic fracture will not always initiate along a perforation, and usually the hydraulic fracture is in a zigzagged shape. When the stress difference and the perforation angle are great, dual fractures will appear along both perforation and the maximum stress directions, verified by laboratory experiments. For improving the accuracy of stress measurement, oriented perforation can reduce the complexity of hydraulic fractures. [ABSTRACT FROM PUBLISHER]

Hydrodenitrogenation (HDN) of isoquinoline (IQ) over Ni and Pd/C were investigated at 200 and 300°C under pressurized hydrogen. The results show that Ni is less active at 200°C but more active at 300°C than Pd/C for HDN of IQ. Raising reaction temperature from 200 to 300°C significantly increased nitrogen removal selectivity. π-Electrondensity of pyridine ring and cleavage of C–N bond were investigated and found to play important roles in HDN of IQ. [ABSTRACT FROM PUBLISHER]

Xilihaote lignite (XL) and Geting bituminous coal (GBC) were extracted using isometric carbon disulfide/acetone binary solvent at 45°C under microwave irradiation. The raw coals and residues were analyzed with a Fourier transform infrared spectrometer and the extracts with a gas chromatograph/mass spectrometer. The results show that the extract yield of GBC is much higher than that of XL lignite and the molecular composition of the extract from XL is significantly different of that from GBC. [ABSTRACT FROM PUBLISHER]

A raw bio-oil (RBO) from pyrolysis of rice husk was upgraded by catalytic esterification with methanol over an acidic resin. Both RBO and the upgraded bio-oil (UBO) were analyzed with a Fourier transform infrared spectrometer, pH meter, and an elemental analyzer. They were extracted sequentially withn-hexane, CCl4, CS2, benzene, and CH2Cl2. All of the extracts were analyzed with gas chromatography/mass spectrometer. The results showed that the carboxylic acids (CA) in the RBO were converted to their corresponding methyl esters (MEs), leading to a significant increase in pH value from 2.8 (RBO) to 5.3 (UBO). The total extract yield of UBO is much higher than that of RBO. In total, 20 CAs and 19 MEs were identified. The CAs include two alkenoic acids, a cycloalkanecarboxylic acid, a hydroxyalkanoic acid, a hydroxyalkenoic acid, an oxyalkanoic acid, a methoxyoxyalkanoic acid, an alkanedioic acid, an oxyalkanedioic acid, an aminoalkanoic acid, two furoic acids, three substituted benzoic acids, and five substituted phenylalkanoic acids. [ABSTRACT FROM PUBLISHER]

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]

A high-temperature coal tar collected from Xuzhou Coking Plant, Saint-Gobain Pipelines (Xuzhou) Co., Ltd. was exhaustively extracted with petroleum ether (PE). The extract was sequentially eluted with PE and PE/carbon disulfide mixed solvent with PE volume contents of 90, 80, 60, 50, and 40% to afford eluates 1 to 6 (E1toE6), respectively. The eluates were analyzed with gas chromatography/mass spectrometer. In total, 12 condensed arenes with 3 to 6 rings and 14 heteroatomic condensed aromatics with 2 to 4 rings were detected inE4toE6. [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]

Shenfu subbituminous coal (SFSBC) and pretreated SFSBC with H2O2were subjected to oxidation with NaOCl at 30°C for 5 h. The results show that the pretreatment with H2O2significantly increased the yields of water-soluble species (WSS), especially benzene carboxylic acids (BCA) and long-chain alkanedioic acids (LCADA), but substantially inhibited the formation of chloro-substituted alkanoic acids. The introduction of oxygen functional groups to SFSBC by the pretreatment (LCADA) could be responsible for the increase in the yields of WSS, especially BCA and LCADA. [ABSTRACT FROM PUBLISHER]

Geting bituminous coal was sequentially and exhaustively extracted with petroleum ester, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature to afford extracts 1–5 (E1-E5). All the extracts were analyzed with a gas chromatography/mass spectrometer. As main components, a series of condensed arenes with 4–6 rings were detected in E2, but only extremely small amounts of the condensed arenes were detected in other extracts. The authors' experiment provides an effective approach for enriching condensed arenes from coals, especially from bituminous coals, such as GBC. [ABSTRACT FROM PUBLISHER]

A series of CoxMn0.06/SiO2 catalysts, which were used for the synthesis of light hydrocarbons from CO hydrogenation, were prepared. The effects of reaction temperature, the morphological and structural properties of the catalysts on the CO conversion and product selectivity were examined. The results show that both CO conversion and C2 to C4 hydrocarbon selectivity are significantly affected by the amount of Co loaded onto the catalysts. The optimum Co content was determined to be 10 wt% (i.e., for Co0.10Mn0.06/SiO2) catalyst, and corresponding CO conversion and the selectivity to C2 to C4 hydrocarbons are 95.3 and 80.6%, respectively, at 400°C. [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]

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]

Bio-oil prepared from flash pyrolysis of rice stalk around 500°C was upgraded by filtration and catalytic esterification. Both raw and upgraded bio-oils were observed with an optical microscope. The upgraded bio-oil was extracted with benzene, carbon disulfide, hexane, and carbon tetrachloride, respectively, and the soluble fractions were analyzed with FTIR and GC/MS. In addition, ion trap mass spectrometer was used for analysis of the benzene-soluble fraction. The results show that the upgrading substantially improved the dispersity of organic droplets in the bio-oil and completely removed char particles from the bio-oil, but heavy species are still the main components in the upgraded bio-oil; the soluble fractions contain aliphatic, benzene-ring-containing, ester, and bonded hydroxyl moieties, and methoxy-containing species are the most abundant GC/MS-detectable compounds. [ABSTRACT FROM AUTHOR]