Identification of Sulfur- and Nitrogen-containing Organic Species in the Extracts from Pocahontas No. 3 Coal

Abstract

Pocahontas No. 3 coal was extracted with CS 2 , n-hexane, benzene, methanol, acetone, and acetone/CS 2 (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 nitrogencontaining 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 nitrogencontaining 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.

Enrichment and Identification of Arylhopanes from Shengli Lignite

“…It is well known that benzo [20,21]hopanes 4−7 (C 32−35 , 2) and benzo [16,17,21]hopanes 6,8,9 (C 31−35 , 3) are formed from compound 1 via the cyclization reactions at C20 and C16, respectively. Some compounds with fluorene and acenaphthene moieties (e.g., compounds 4 and 5) in coals should be partially produced from D-ring monoaromatic 8 (14)-secobenzo [20,21]hopanes 6,10,11 (C 32−35 , 6) and 8 (14)-secobenzo [16,17,21]hopanes 11,12 (C 31−35 , 7), which are produced from the corresponding benzohopanes (i.e., compounds 2 and 3) via aromatization and C8−C14 bond cleavage, respectively. Coals are rich in the compounds with two aromatic moieties linked by −(CH 2 ) n −, such as 1-benzylnaphthalene ( 8), but their origin is still unclear.…”

Application of mass spectrometry in the characterization of chemicals in coal‐derived liquids

“…S‐ heterocyclic aromatics, such as benzothiophene, dibenzothiophene, and benzo[ b ]naphthothiophene along with their alkylated homologues, were identified by GC and GC/MS. In addition, some thiols, sulfides, and disulfides likewise were tentatively detected in the extracts by the high‐resolution MS. Cao et al () also reported dibenzothiophenes, benzo[ b ]naphthothiophenes, and their methylated homologues in the extracts from sequential extraction of Pocahontas No. 3 coal.…”

“…NCCs in extracts from coal extraction and thermal dissolution can more truly represent the original nitrogen forms in coals since the cleavage of covalent bonds involving N almost does not occur during low‐temperature extraction and thermal dissolution. Several investigations have focused on the separation and characterization of NCCs in the extracts from low‐temperature extraction (Ding et al, ; Wei, Wang, & Zong, ; Cao et al, ) and thermal dissolution (Liu et al, ; Wang et al, ) of coals. Ding et al () separated a series of fatty acid amides from Shengli lignite through extraction in carbon disulfide followed by column chromatography and identified by GC/MS.…”

“…The detected fatty acid amides are composed of fourteen alkanamides (C 15 –C 28 ) and three alkenamides (C 18 and C 22 ), as listed in Table . Sequential Soxhlet and ultrasonic extractions in different solvents followed by GC/MS analysis of the extracts have been used for characterizing NCCs in coals (Wei, Wang, & Zong, ; Cao et al, ). NCCs, such as pyridines, quinolines, benzo[ d ]imidazoles, and arylamines, were detected by GC/MS in the extracts from sequential thermal dissolution of extraction residue from Xianfeng lignite, and pyridines are the most abundant NCCs.…”

The Effect of Pretreatment with H2O2on the Oxidation of Shenfu Subbituminous Coal with NaOCl

“…Various NCSs were identified from extracts of coals Ding et al, 2008;Zong et al, 2009;Wei et al, 2009;Cao et al, 2010) and reaction mixtures of coals (Wei et al, 2002;Liu et al, 2003), but to the authors' knowledge, no reports were issued on the detection of any NCSs in the products from coal oxidation.…”