Computer generation of a network of elementary steps for coke formation during the thermal cracking of hydrocarbons

The methodology for developing a detailed network for coke formation during thermal cracking of hydrocarbons is described. Coke is represented as an aromatic structure. Coke growth is described by elementary reactions between surface species and the components present in the gas phase. The elementary reactions can be divided into five classes of reversible reactions: hydrogen abstraction, substitution, addition by gas phase radicals, addition to gas phase olefins and cyclization. The complete network for coke formation during ethane cracking contains over 14,000 reaction steps between 2400 reaction components, the latter being determined not only by the surface species but also by their local environment. (C) 2001 Elsevier Science B.V. All rights reserved.