Hydrocarbon pyrolysis, molecular reaction model

Molecular reaction schemes have a long history of use in the design of pyrolysis coils. Since the pioneer works of Myers and Watson [46] and Schutt [47] on propane pyrolysis, improved by Snow and Schutt [48], molecular reaction schemes have been applied to the modelling of the pyrolysis of light and heavy hydrocarbons [38, 49—56]. Froment and co-workers have extensively promoted molecular reaction schemes in a series of papers [57—61] a brief account can be found in a book by Froment and Bischoff [25]. 

Mos of the solid carbonaceous material available to industry is derived from the pyrolysis of petroleum residues, coal, and coal tar residues. Understanding the reactions occurring during pyrolysis would be beneficial in conducting materials research on the manufacture of carbonaceous products. The pyrolysis of aromatic hydrocarbons has been reported to involve condensation and polymerization reactions that produce complex carbonaceous materials (I). Interest in the mechanism of pyrolysis of aromatic compounds is evidenced in a recent study by Edstrom and Lewis (2) on the differential thermal analysis of 84 model aromatic hydrocarbons. The study demonstrated that carbon formation was related to the molecular size of the compound and to energetic factors that could be estimated from ionization potentials. 

The use of computer generation systems in modelling the pyrolysis of large hydrocarbons is no longer considered simply an alternative to manual mechanism construction. It has become a necessity. The quantity of species and reactions becomes enormous, increasing molecular weight. This is particularly true if the focus is not merely on linear alkanes but also on other typical components of naphthas and gasoils, such as Bo-alkancs or cyc/o-alkanes, where the number of possible isomers increases exponentially with the number of carbon atoms in the molecule. 

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