| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 205898 | Fuel | 2015 | 7 Pages |
•Numerous basic species in ethanol-soluble portion from Zhaotong lignite were detected.•N1Ox class species with 1–12 DBE and 8–34 carbon numbers are dominant in the portion.•Molecular mass of the detected species in the portion ranges from 100 to 600 u.•Pyridines and quinolines are the main basic nitrogen species in the portion.
Ethanol-soluble portion (ESP) from Zhaotong lignite ethanolysis at 305 °C was analyzed with a positive-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). The range of molecular mass distribution is from m/z 100 to 600 with the center around m/z 330. Assignment of molecular formulae reveals that the main nitrogen-containing species with relative content of 86.4% are most probably basic nitrogen compounds (BNCs) ionized during ESI in positive-ion mode. The BNCs are N1Ox (x = 0–5) and N2Oy (y = 0–2) with 0–14 double bond equivalent (DBE) values and 9–39 carbon numbers. According to DBE distributions, pyridines and quinolines should be predominant BNCs in the ESP. In addition, amines (DBE < 4) were also identified in the ESP. The average DBE values are 6–8 for N1Ox class species and 7 and 8 for N2Ox class species, indicating that pyridines (or quinolones) and quinolines with an amino group are characteristic structures for N1Ox and N2Ox classes, respectively. Positive-ion ESI FT-ICR MS proved to be a powerful tool for identifying BNCs in coal-derived liquids.
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