Y.-P. Zhao

The Enrichment and Identification of Methyl Alkanones from Thermally Soluble Shengli Lignite

Shengli lignite was subjected to thermal dissolution in a methanol/benzene mixed solvent at 240°C for 1 h. The soluble fraction was sequentially eluted with petroleum ether and 5, 10, and 15% carbon disulfide/petroleum ether mixed solvents through a silica gel-packed column to afford eluted fractions 1 to 4 (EF1 to EF4). In total, 15 methyl alkanones from C15 to C27, including 2 methyl side-chain alkanones and 13 methyl straight-chain alkanones were enriched in EF4 and identified with gas chromatography/mass spectrometry.

Separation and identification of organic compounds from thermally dissolved Shengli lignite in a methanol/benzene mixed solvent

Thermal dissolution of Shengli lignite was conducted in a methanol/benzene mixed solvent at 240oC for 1 h. The soluble fraction was sequentially eluted with petroleum ether (PE) and carbon disulfide (CDS)/ PE mixed solvents with increased CDS to PE ratio through a silica gel-packed column. A series of normal alkanes, polycyclic aromatics, methyl alkanoates, alkanoic acids, and fatty acid amides were enriched to large extents and 6-hydroxy-7-isopropyl-1,1,4a-trimethyl-2,3,4,4a,10, 10a-hexahydrophenanthren-9(1H)-one was successfully separated with high purity by the column chromatography.

The Identification of Organooxygen Compounds in Geting Bituminous Coal

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 (E1 to E5). In total, 77 organooxygen compounds (OOCs) were identified from E3 by 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.

The Enrichment of Condensed Arenes in Geting Bituminous Coal

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.

Enrichment of oxygen–containing aromatics in an extract from Zhundong subbituminous coal

Zhundong subbituminous coal (ZSBC) was exhaustively extracted with isometric carbon disulfide (CDS)/acetone mixed solvent to afford extract 1 (E 1 ), which was sequentially extracted with petroleum ether (PE) and CDS to afford extracts 2 (E 2 ) and 3 (E 3 ). E 3 was gradiently eluted into effluent portions 1 to 5 (EPs 1 to 5) through a silica gel-packed column sequentially with PE, CDS/PE mixed solvents with volume ratio of 3:7, 1:1 and 7:3, and CDS. According to analysis with a gas chromatography/mass spectrometer, in total, 22 alkyl phenyl carbonates were enriched into EP 3 , and anthraquinone and its two derivatives, nine polycyclic aromatic ketones and two polycyclic aromatic lactones into EP 4 . Most of the oxygen-containing aromatics are value-added chemicals.

The Isolation of Condensed Arenes from Shenmu-Fugu Coal Liquefaction Residue

Shenmu-Fugu subbituminous coal liquefaction residue was exhaustively extracted with petroleum ether (PE) to afford PE-extractable fraction (PEEF), which was then eluted with petroleum ether through a silica gel-filled column. The PEEF and eluates were analyzed with a gas chromatographer/mass spectrometer and a Fourier transform infrared spectrometer. As a result, a number of 4- to 7-ring condensed arenes (CAS) were detected in the PEEF series of 4- to 6-ring CAs along with long-chain alkanes were isolated from the PEEF by column chromatography.

The compositional features of thermally soluble fractions from two Chinese coals in cyclohexane

Shengli lignite (SL) and Shenmu-Fugu subbituminous coal (SFSBC) were subjected to thermal dissolution in cyclohexane at 300°C for 1 h under hydrogen. The reaction mixtures were extracted with petroleum ether (PE) and the PE-extractable fractions (PEEFs) were analyzed with a gas chromatography/mass spectrometer. The results show that the PEEFs from thermally dissolved SL (TDSL) and thermally dissolved SFSBC (TDSFSBC) mainly consist of alkanes, alkenes, arenes, and oxygen-containing organic compounds (OCOCs); the yields of alkanes and alkenes in the PEEF from TDSFSBC are appreciably higher than those from TDSL, while the yields of arenes and oxygen-containing organic compounds in the petroleum ether-extractable fraction from thermally dissolved Shenmu-Fugu subbituminous coal are significantly lower than those from thermally dissolved Shengli lignite; arenols are dominant OCOCs in the PEEF from TDSL, while main OCOCs in the PEEFs from TDSFSBC are arenols and esters.

Thermal dissolution of Shengli lignite in ethyl acetate

Thermal dissolution (TD) of Shengli lignite (SL) in ethyl acetate (EA) was carried out under different conditions, including temperature, solvent to SL ratio ( RS/SL), and time. The yields of EA-extractable fractions (EAEFs) increased with raising temperature from 240–300°C, but then decreased when the temperature was higher than 300°C, and the effects of RS/SL and time on EAEF yields was slight when RS/SL and time exceeded 20/1 and 1 h, respectively. These results suggest the optimal conditions for the TD of SL are 300°C, 20/1 of RS/SL, and 1 h. Then a couple of scale-up experiments were carried out under the optimal conditions with SL and dehydrated SL. According to analysis with a gas chromatography/mass spectrometry, major species in the EAEF from the TD of SL are oxygen-, sulfur-, and nitrogen-containing organic compounds along with elemental sulfur. The sulfur- and nitrogen-containing organic compounds detected include thioethers, thiophenes, amines, and nitrocyclic compounds. According to the structural characteristics of organic compounds in the EAEF, the mechanism for the TD of SL with EA was presumed.

Catalytic hydroconversion of Lingwu bituminous coal over Fe-S/γ-Al2O3

Fe-S/γ-Al2O3 was prepared by thermally decomposing Fe(CO)5 onto γ-Al2O3 and subsequent sulphurisation with sublimed sulphur in a magnetically stirred autoclave and used as the catalyst for catalytic hydroconversion (CHC) of Lingwu bituminous coal (LBC). Non-catalytic hydroconversion (NCHC) and CHC of LBC were conducted in cyclohexane under 5 MPa of initial hydrogen pressure at 300°C. The reaction mixtures were extracted with petroleum ether and analysed with a gas chromatography/mass spectrometer. The results show that Fe-S/γ-Al2O3 significantly catalysed the formation of hydroarenes, arenes and arenols and completely removed 2,5-dimethylthiophene from LBC.

The Identification of Soluble Nitrogen-containing Organic Species in Two Chinese Lignites

Shengli lignite (SL) and Xiaolongtan lignite (XL) were extracted with carbon disulfide, benzene, methanol, acetone, and tetrahydrofuran sequentially. The OFs of organinitrogen compounds in the lignites and their residues were characterized by X-ray photoelectron spectroscopic analysis, and the nitrogen-containing organic species in the extracts were identified with gas chromatography/mass spectrometer. The results show that pyridinic nitrogen Np, pyrrolic nitrogen Np′, quaternary nitrogen Nq, and oxidized nitrogen No are the four OFs of organic nitrogen in the two lignites, and the content of Np′ in XL is higher than that in SL. The relative contents (RCs) of pyridines and quinolines in the extracts from XL are higher than those from SL, while the RCs of amides and amines in the extracts from SL were higher than those from XL.