Structural features of liquefaction residue from Shenmu-Fugu subbituminous coal

Abstract

Liquefaction residue (LRSFSBC) from Shenmu-Fugu subbituminous coal was ultrasonically extracted with petroleum ether, methanol, cyclohexane, ethyl acetate, acetone, carbon disulfide (CDS) and isometric CDS/acetone mixture (IMCDSAM), respectively. A number of alkanes, arenes, arenols, alkanols, alkenones, esters, and nitrogen-containing organic compounds were identified according to the analyses with Fourier transform infrared spectrometer, gas chromatograph/mass spectrometer, direct analysis in real-time ionization source coupled with ion trap mass spectrometer, and solid-state 13C nuclear magnetic resonance (SS 13C NMR). The tetra- and penta-substituted anthracene or phenanthrene unit could be the average structures in LRSFSBC by SS 13C NMR analysis. The main intermolecular interactions among the organic species in LRSFSBC are π–hydrogen bonds and π–π interactions. These interactions are also the cause for “capsule” formation. Stronger interactions between LRSFSBC and solvents, especially CDS and IMCDSAM, destroyed the interactions and thereby led to high extract yields.