The behavior of fluidized bed reactors has been the object of intense research due to its paramount importance in many chemical processes such as Fluidized Catalytic Cracking (FCC) in the petroleum refining industry. Despite the effort, there are many aspects, which are not yet fully understood, such as the dynamic flow behavior inside these reactors. Academic groups have been joining their efforts along with petrochemical industries to understand more deeply the internal flow of petrochemical regenerators with a view to optimize the FCC process. In the last two decades, computational fluid dynamics (CFD) has proved to be an invaluable tool to investigate the behavior of this equipment. The aim of this study is to model the behavior of a gas-solid three-dimensional fluidized bed reactor with a central jet using a CFD approach.
The numerical data from the model has been obtained using the commercial software package CFX4.4 from AEA technology. The CFD model is based on a two fluid Eulerian-Eulerian model where the two phases are modeled as a continuum.
Simulations of the gas-solid fluidized bed are made using both a two and a three-dimensional model. The numerical results are consistent qualitatively and quantitatively with numerical data reported in the literature.
Fluidized bed reactors are intensively used in many chemical industries such as chemical, petrochemical, food industry and paper manufacturing. The Fluidized Catalytic Cracking process (FCC) is the most complex and profitable process in the petroleum refining industry. The FCC success is due mainly to two factors:
it is a very flexible process and is capable of producing the real need of the local consuming market;
it is economically advantageous. It converts oil of low commercial value in noble derivatives, of higher aggregated value, such as gasoline, and GLP.
The FCC process can be split into two main stages:
the catalytic cracking, where the oil composed of larger molecules are converted into lighter fractions through a catalytic reaction;
the regeneration of the catalyst through the burning of the coke deposited on its surface.
The regenerator of a petrochemical unit is known as the lung of the FCC unit. The large experience in the design and operation of this equipment makes its operation reasonably optimized. However, it is clear that any improvement either in design or in operation of the regenerator will represent a great economy in the whole process. The design of the regenerators to date is based on the BLOCK 2 - - FORUM 8 85 A THREE DIMENSIONAL COMUT
