The petrological features and chemical structure in liquefaction residues of coal rich in semi-fusinite.

The coal rich in semi-fusinite was selected to run liquefaction rests in tubing-bomb reactors in a pre-heated sand bath. The petrological features of liquefaction residues were observed by microscopy, and the comparative discussion on chemical structure on raw coal and relatively liquefaction residues were presented by using FF-IR, 13C-NMR, and Py-GC/MS techniques. The results show that the liquefaction conversion reaches to more than 50% although coal used with high semi-fusinite content. The optical examination of liquefaction residues show that the partial semi-fusinites become plastic, and even formes hollow spheres, which indicate that semi-fusinites have involved in the liquefaction reaction. The comparison of chemical structure of raw coal and relatively liquefaction residues clearly show that the changes of chemical structures during liquefaction are occurred. Furthermore, the results of Py-GC/MS show that the compounds in residue are mainly composed of alklynaphthalene, C2-naphthalene and C3-naphthalene are main constitutions. Finally, the role of semi-fusinite in liquefaction was further discussed according to the results of speculation and petrological features. [ABSTRACT FROM AUTHOR]