(244c) A Generic Hydrodynamic Model of Fluid Catalytic Cracking (FCC) Riser Reactor

While commercial FCC riser reactor converts heavy hydrocarbon petroleum fractions into a slate of more usable products, mass transfer, momentum transfer, heat transfer, catalytic cracking reaction and phase transfer are entangled and occur simultaneously inside the riser reactor. Since the FCC process is in nature strong inter-coupled with multiphase flow hydrodynamics, in order to predict accurate behavior of the riser reactor, all these processes need to be comprehensive modeled. Unfortunately most of published literature focused too much on the FCC process itself without paying enough attention to significant influence on the cracking kinetics from multiphase flow hydrodynamic, such as local catalyst concentration, local catalyst velocity and even catalyst average size. The aim of this work is to develop a generic modeling approach which can fully incorporate multiphase flow hydrodynamics with FCC process. The emphasis of this model is to develop a framework to simultaneously simulate the multiphase flow hydrodynamics, cracking reaction and their inter-coupling characteristics in riser reactor. As a global approach, the modeling of cracking kinetics is still based on lumping of compounds which are made on the basis of boiling range of feed stocks and corresponding products in the reaction system. In order to avoid the mathematical complexities, four lump kinetic schemes are being used in this work. This modeling approach opens up a new dimension for making generic models suitable for the analysis and control studies of FCC units. Predictions of the model will compare with the yield pattern of industrial scale plant data reported in literature.