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Shengli lignite (SL) was subjected to sequential extraction (SE) with carbon disulfide, benzene, methanol, acetone, and tetrahydrofuran under ultrasonication to afford extracts 1–5, respectively, and the residue (R SE , i.e., residue from SE). The R SE was subjected to sequential thermal dissolution (STD) in benzene, methanol, and acetone in a batch autoclave from 210 to 330 °C to afford soluble portions (SPs) and the residue (R STD , i.e., residue from STD). The total yield of extracts 1–5 is only 2.86%, while the yields of SPs from STD in benzene, methanol, and acetone are 5.69%, 10.15%, and 48.41%, respectively. The SPs from STD in benzene and methanol mainly consist of hydrocarbons and phenols, while ketones are the main compounds detected in the SP from STD in acetone and most of nitrogen-containing organic compounds appear in the SP from STD in acetone. During STD in acetone, acetone conversion to phorone, isophorone, and their derivatives was confirmed. [ABSTRACT FROM AUTHOR]

Shengli lignite (SL) was oxidized and depolymerized in aqueous sodium hypochlorite under mild conditions followed by sequential extraction with ethoxyethane and ethyl acetate. The extracts were analyzed by Fourier transform infrared spectroscopy, gas chromatograph/mass spectrometry (GC/MS), time-of-flight mass spectrometry (TOF-MS) equipped with electrospray ionization (ESI), and direct analysis in real time (DART) to understand the structural features of SL. In total, 130, 272, and 818 compounds were identified by GC/MS, ESI-MS, and DART-MS, respectively, and the corresponding molecular mass distributions are between 70 and 322, 114 and 664, 113 and 753 u , respectively. GC/MS detected molecules with low molecular mass and polarity, and the major species include aliphatic acids, benzene polycarboxylic acids, chloro-substituted species and nitrogen-containing compounds. A large number of heteroatom-containing compounds (oxygen, nitrogen and sulfur) with relatively high molecular mass and unsaturation degree were determined using ESI-MS. As an ambient ionization technique, DART speeded up the analysis time with little or no sample pretreatment. Compared to the other two MS techniques, DART-MS broadened the measurement range, and O x N 5 , and O x N 6 classes were only detected by DART-MS. [ABSTRACT FROM AUTHOR]

A three-step degradation, including sequential ultrasonic extraction (UE), sequential thermal extraction (TE), and ruthenium ion-catalyzed oxidation (RICO), of Xianfeng lignite (XL) was performed to characterize the organonitrogen species (ONSs) in XL. More than 87.3% of organic matter in XL was converted into soluble portions through the degradation. The analysis with X-ray photoelectron spectrometer shows that pyrrolic, amino, and quaternary nitrogen species are the main nitrogen forms both in XL and its residue from UE, while nitroaromatics, chemisorbed N-oxides, and pyrrolic nitrogen are predominant in the residue from TE. A series of ONSs, including pyridines, quinolines, benzo[d]imidazoles, and arylamines, were identified in the extracts from TE of the UE residue according to GC/MS analysis. Among the ONSs, pyridines and quinolines are the most abundant. The ONSs could be released by thermally destroying noncovalent bonds, such as hydrogen bonds and aromatic π-π interactions, during TE of the UE residue. Most of ONSs released from RICO of the TE residue could be generated from the degradation of nitrogen-containing macromolecular aromatics in XL matrix (XLM). Nitrobenzenecarboxylic acids are the most abundant ONSs released from RICO of the TE residue and should be released by the degradation of macromolecular nitroaromatics in XLM. [ABSTRACT FROM AUTHOR]

A highly dispersive Fe/ZSM-5 as the precursor of Fe-S/ZSM-5 was prepared by decomposing Fe(CO)5 onto ZSM-5 zeolite at 250°C. Shengli lignite (SL) was isolated to extractable portion (EP) and extraction residue (ER) by exhaustive extraction with isometric carbon disulfide/acetone mixed solvent (IMCDSAMS) under ultrasonic irradiation. The EP and ER were analyzed with a direct analysis in real time ionization source coupled to ion trap mass spectrometer. Both of them and SL were analyzed with a Fourier transform infrared spectrometer. The ER was subjected to non-catalytic hydroconversion (NCHC) and catalytic hydroconversion (CHC) over Fe-S/ZSM-5, which was formed by in situ reaction of Fe/ZSM-5 with sulfur added, in cyclohexane under pressurized hydrogen at 300°C. The reaction mixtures were sequentially extracted with petroleum ether, carbon disulfide, methanol, acetone, and IMCDSAMS to afford extracts 1-5 (E1-E5), which were analyzed with a gas chromatography/mass spectrometer (GC/MS). As model reactions, the CHCs of di(1-naphthyl)methane (DNM) and diphenylmethane (DPM) over Fe-S/ZSM-5 were also conducted in cyclohexane at 300°C. The results show that more than 50% of organic matter in the ER was converted to a soluble portion by the CHC, whereas the yield of soluble portion from the NCHC is only 10.52%. GC/MS-detectable species only appear in the E1, which mainly consists of alkanes, arenes, and arenols either from the NCHC or from the CHC. DNM was selectively hydrocracked to naphthalene and 1-methylnaphthalene over Fe-S/ZSM-5, while DPM hydrocracking did not proceed, indicating that Fe-S/ZSM-5 catalyzed the formation of radical hydrogen from molecular hydrogen and subsequent radical hydrogen transfer (RHT) to the ipso-position of naphthalene ring in DNM. Some CH2 and O in the ER could be connected to condensed aromatic rings (CARs). Analogously, RHT to the ipso-position of CARs in the ER resulted in the release of arenes and phenols from the ER. [ABSTRACT FROM AUTHOR]