PYROLYSIS OF COAL-TAR PITCH MIXED IN THE PRESENCE OF A GRAPHITE-INTERCALATION COMPOUND - A KINETIC-STUDY

A kinetic study has been carried out to determine the influence of the addition of first stage FeCl3-graphite intercalation compound (GIC) t o coal tar pitch (CTP) on the formation Ind the development of the mes ophase. The mesophase formation was followed by the determination of t he tetrahydrofuran insoluble fraction (THFI) of the solid residues, wh ich were further characterized by polarized light microscopy. The pres ence of the Lewis acid (desorbed from the graphite layers) has a great influence during the mesophase spherule formation and development. Th e activation energy of the formation and the development of the mesoph ase (E-a) is equal to 159 and 204 kJ/mol in the case of the CTP-GIC 8% mixture and the CTP respectively. This corresponds to a decrease of 2 2% of E-a when the CTP is mixed with the GIG. The authors want to high light the difficulties and mainly the limitations of the method used t o calculate this activation energy by THFI measurements. However, we a ssume that the mesophase formation and growth rates are accelerated in the presence of compounds such as GIC for two reasons: the absence of QI particles on the surface of the mesophase spherules and the cataly tic activity of the Lewis acid. (C) 1998 Elsevier Science Ltd. All rig hts reserved.