CHEMICAL STRUCTURE AND CARBONIZATION BEHAVIORS OF AIR-BLOWN PITCHES

A series of pitches were prepared from QI free coal tar through air blowing at 300?℃ for 2?h～12?h. The air blown pitches and raw coal tar were characterized by elemental analysis, FTIR, 1? H-NMR , 13 ? C-NMR , solubility, and optical microscopy. The results showed that air blowing could promote the dehydrogenative condensation reaction between pitch moleculars. The α hydrogen in raw coal tar decreased with air blowing time, while oxygen content had no significant increase in the resulted pitch. The air blown pitches and raw coal tar were carbonized at 480?℃ under 0.1?MPa and 1.6?MPa respectively. It demonstrated that the air blowing at low temperatures was a simple procedure for increasing the coke yield, although it tended to suppress the growth of optical anisotropy at the following carbonization process.