The valorisation of oil distillation residues constitutes a major problem for refineries. Thermal processes like visbreaking and delayed coking are still quite diffused
technologies. This paper presents some major aspects of the delayed coking kinetic modelling and some preliminary results compared with experimental data. A
mechanistic approach has been adopted; it allows describing the process in wide ranges of operating condition and feedstocks. The developed model can be a useful tool for feedstock selection, production planning, control and optimisation. A special attention is devoted in the paper to substitutive addition reactions responsible of coke formation into the drums
