Pyrolysis of coal tar pitch mixed in the presence of a graphite intercalation compound: A kinetic study

Abstract

A kinetic study has been carried out to determine the influence of the addition of first stage FeCl 3-graphite intercalation compound (GIC) to coal tar pitch (CTP) on the formation and the development of the mesophase. The mesophase formation was followed by the determination of the tetrahydrofuran insoluble fraction (THFI) of the solid residues, which were further characterized by polarized light microscopy. The presence of the Lewis acid (desorbed from the graphite layers) has a great influence during the mesophase spherule formation and development. The activation energy of the formation and the development of the mesophase (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 22% of E a when the CTP is mixed with the GIC. The authors want to highlight the difficulties and mainly the limitations of the method used to calculate this activation energy by THFI measurements. However, we assume 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 catalytic activity of the Lewis acid.