Structural
Features of Extraction Residues from Supercritical Methanolysis of
Two Chinese Lignites
- Publication date
- Publisher
Abstract
The
methanol-insoluble portions from supercritical methanolysis of Shengli
lignite (SL) and Huolinguole lignite (HL) were extracted with an isometric
carbon disulfide/acetone mixed solvent under ultrasonic irradiation
to afford extracts and extraction residues (ERs). The ERs were subjected
to ruthenium-ion-catalyzed oxidation, and soluble portions were separated
from the reaction mixture and esterified. The resulting products were
analyzed with a gas chromatography/mass spectrometer and atmospheric
solids analysis probe/time-of-flight mass spectrometer to reveal structural
features of heavy species in the two lignites. The results show that
the ER from SL is richer in highly condensed aromatic species than
that from HL, while both ERs have the same carbon number range (C<sub>9</sub>–C<sub>24</sub>) of alkyl groups with the highest content
at C<sub>15</sub> on aromatic rings and the same distribution of alkylene
bridges (C<sub>2</sub>–C<sub>20</sub>) connecting aromatic
rings with a higher abundance of shorter linkages than that of longer
linkages