Relationship between chemical composition and pyrolysis behaviour of a medium temperature pitch (or Lurgi-gasifier pitch)

This paper studies the chemical composition and pyrolysis behaviour of a medium temperature pitch produced in the SASOL–Lurgi coal gasification process. The results are compared to a commercial petroleum pitch and a commercial binder coal-tar pitch. The SASOL pitch had a high content in oxygen, mainly forming phenols, which make it very reactive at temperatures between 410 and 430 °C, temperatures at which the commercial pitches do not react in a great extent. Despite the high reactivity shown by the SASOL pitch, anisotropic structures, of peculiar shapes, where developed on pyrolysis. Also noticeable is the low polyaromatic hydrocarbon (PAH) content of this pitch, which is of significant interest from a safety and environmental point of view. On the light of these results, possible applications for the SASOL pitch are pointed out.