Molecular modeling of the early stages of carbonization of primary heavy aromatic compounds in decant oil and its derivatives

Needle coke, a textured carbon, is produced by the liquid-phase carbonization of FCC decant oil, or its derivates. The texture of needle coke depends on the formation of a liquid crystalline intermediate phase, carbonaceous mesophase, during carbonization. The mesophase formation depends, in turn, on the molecular composition of feedstocks. Heavy ends of decant oils consist of PAH with four to six condensed rings with a high degree of alkylation. In this study, phenanthrene, pyrene, chrysene, benzopyrene, and benzo[ghi]perylene were selected as monomers to model the initial stages of free radical formation and polymerization using a semi-empirical MOPAC approach. The side chain cleavage from parent PAH is the primary means of free radical initiation. The local reactive sites on the PAH depends on the configuration of the ring structure. This is an abstract of a paper presented at the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).