Characterizations of the Extracts from Geting Bituminous Coal by Spectrometries

Abstract

Geting bituminous coal (GBC) was sequentially extracted with petroleum ether, carbon disulfide (CDS), methanol, acetone, and isometric CDS/acetone mixed solvent at room temperature to afford extracts 1–5 (E1–E5) and residue. Detailed characterizations of the extracts were performed with a gas chromatography/mass spectrometer (GC/MS), Fourier transform infrared (FTIR) spectrometer, and direct analysis in real-time ionization source (DARTIS) coupled to an ion-trap mass spectrometer (ITMS). GBC and its residue were also analyzed with the FTIR spectrometer. Particle sizes of the residue were significantly reduced compared to those of GBC according to the observation with a scanning electron microscope. Arenes with 1–4 rings and more condensed arenes were enriched into E1 and E2, respectively, while more heteroatom-containing organic species were detected in other extracts, especially in E3 and E4 according to GC/MS analysis. The extracts, especially E1–E4, contain more aliphatic moieties and less aromatic moieties compared to GBC and its residue based on FTIR analysis. DARTIS/ITMS proved to be a powerful tool for analyzing thermally labile and/or involatile species, which are difficult to be identified with GC/MS, in the extracts.

Characterization of humic acids extracted from a lignite and interpretation for the mass spectra

“…15,16 Modern instrumental analyses such as Fourier transform infrared spectroscopy (FTIR), 17 scanning electron microscopy (SEM), 18 and gas chromatography/mass spectrometry (GC/MS) 19 have been applied in the characterization of the compositions of complex biomass/coal. Olivella and co-workers used analytical pyrolysis coupled with GC/MS to obtain the detailed molecular structure information of humic acids from Spanish leonardite coal.…”

“…Shi et al studied Geting bituminous coal using SEM and FTIR to learn the surface morphology of raw coal/extraction residue and structural details such as chemical functional groups, respectively. 18 The extracts obtained from Geting bituminous coal through sequential solvent extraction contained more aliphatic components and less aromatic compounds compared with raw coal and its extraction residue. The combination of different analytical methods can promote in-depth investigation on the composition of humic acids that originate from lignite at the molecular level.…”

Insight into the structural features of Zhaotong lignite using multiple techniques

“…Coals are too complex to be elaboratively characterized. It is common to understand original structural information on coals with direct characterization tools, such as solid-state 13 C nuclear magnetic resonance (NMR) [6][7][8], Fourier transform infrared (FTIR) spectrometer [9,10], and X-ray photoelectron spectrometer (XPS) [11][12][13]. http Analyses with such tools greatly facilitate the understanding of carbon skeleton structures and functional groups along with oxygen, nitrogen, and sulfur forms in coals.…”

Effects of hydrogen and FeNi–S/γ-Al 2 O 3 on the hydroconversion of extraction residue from Geting bituminous coal in cyclohexane

“…Compared with TD, the yields of long-chain normal alkanes are much lower under other 3 reaction conditions, indicating that the pressurized gas atmosphere and catalyst facilitate the rupture of long-chain normal alkanes. According to previous investigations, long-chain normal alkanes were detected in the extract of GBC [35], but in the current investigation, relatively free alkanes were ultrasonically extracted, thus the alkanes could inherently exist in ER GBC and be wrapped into macromolecular structures in ER GBC due to "capsule effect" [36]. The pressurized gas atmosphere, especially H 2 , and catalyst could destroy the "capsule structure" and release the wrapped alkanes in ER GBC , resulting in an increase in the yields of alkanes.…”