Interface Structure between Vitrinite and Inertinite from Shenmu Coal during Pyrolysis

This research investigated the pyrolytic characteristics of the interface between vitrinite and inertinite, exploring the structure and changes at the interface. The various features of macerals and their interface during pyrolysis were analyzed using Fourier transform infrared microspectroscopy and a scanning electron microscope, and the crystallite structures of the macerals were observed using a transmission electron microscope. The results showed an interaction between Shenmu vitrinite and inertinite at their interface. The interface generally showed a gradual changing of pyrolytic degree from the surface toward the center of the layers during pyrolysis. However, cracks from the escape of vitrinite volatile substances terminated at the inertinite layer, which then changed the original mode of heat transfer at the interface and caused a remarkable mutation. The compatibility of the interface structure between vitrinite and inertinite could be improved by heat treatment, which strengthens the aromatic skeletal structures. In addition, the growth of aromatic fringes could be enhanced but inertinite showed a faster progress of graphitization than vitrinite during pyrolysis.