Comparative study of carbonization of hydrocarbons. The 24/26 rule.

Comparative study of different types of carbonization of hydrocarbons, i.e. , electric discharges, thermal pyrolysis and pyrolysis in flame is reported . On the basis of GC/MS experiments, it can be concluded that a large numbe r of compounds, mainly polycyclic aromatic hydrocarbons (PAHs) were formed in each cases. Similar PAHs were formed independently of the starting mater ial, i.e., hexane or naphthalene. The formation of PAHs was explained by th e 24/26 rule, i.e., the molar mass of PAHs increases by C-2 or/and C2H2 uni t incorporation, regularly. The GC/MS investigation reveals that the C-2 or /and C2H2 incorporation takes place in both odd and even series of carbon a tom number of PAHs. Fullerene formation was, however, observed only in the case of high temperature process, i.e., electric discharges. (C) 1999 Elsev ier Science Ltd. All rights reserved.