Based on the full range of published data in fluidized-bed catalytic cracking (FCC) performance and kinetic rates, and adapted to the industrial unit of the PETROBRAS' Alberto Pasqualini Refinery (REFAP), an integrated dynamic model for the UOP stacked FCC is developed. The model is capable to capture the major dynamics effects that occur in this system. It shows a comparison between regenerator dense phase modeling like continuous stirred lank reactor (CSTR) and emulsion-bubble bed. The model represented by a nan-linear system of differential-algebraic equations, was written in language C and implemented in MATLAB/SIMULINK. The results are compared with the data obtained in the REFAP industrial plant.