(740h) 3D CFD Mesh Configurations and Turbulence Models Studies and Their Influence On the Industrial Risers of Fluid Catalytic Cracking

One of the most important applications of the gas-solid fluidization is the fluidized catalytic cracking (FCC) process in petroleum refineries. In order to describe the large number of components present in heavy distillates and the kinetic models that are able to predict the profiles of heavy and light chemical fractions in industrial risers, the four lump approach has been used, where each lump represents hundreds of molecules in a specific range of molecular weight.

This study analyses the influence of  k-e and the Shear Stress Transport Models (SST) as well as hexahedral and tetrahedral mesh configurations on the fluid dynamic behavior of fluid catalytic cracking (FCC). The catalyst distribution field and production of gasoline were analyzed for each case. A four lump kinetic model in which the heavy oil (gas oil) is converted into gasoline and light hydrocarbon gas was adopted. Equations were solved numerically by finite volume method using a three-dimensional Eulerian-Eulerian approach with a commercial CFD code, CFX version 13.0. Appropriate functions were implemented in the model by considering the heterogeneous kinetics and catalyst deactivation. The simulation results were validated against the experimental results reported in the literature by Farag et al (1994) and Derouin et al. (1997).

It was found that conversion of gas oil and production yield of gasoline depend on the turbulence models and mesh configurations.