Abstract: A predictive kinetic model is disclosed for simulating fluid catalytic cracking of large hydrocarbon molecules having a lumping scheme that includes hydrocarbon descriptions based on boiling point distribution and chemical properties. The simulation results in a nearly continuous prediction of products as function of boiling point temperature. The lumping scheme defines a relatively large number of small fixed boiling-point range pseudo-components for describing product material, and a smaller number of larger boiling-point range pseudo-components for describing feed conversion and selectivity. The chemical properties for describing hydrocarbons include total hydrogen, aromatic carbon and aromatic hydrogen.